Background and Aims: The rate of variation in various genes of a bacterial species is
different during evolution. Therefore, in systematic bacterial studies many researchers compare
the phylogenetic tree of a particular gene to the standard tree of an rRNA gene. Regarding the
importance of 16SrRNA gene and the evolutionary process of RecA protein family, we
investigated the changes in sequences of the RecA protein family in selected bacterial phylums
in comparing with their 16SrRNA genes.
Materials and Methods: For this purpose, sequences of the RecA protein family were
extracted from Uniprot database (with some help from ProSite) and then they were categorized
by using CD-hit algorithm. One species was selected from each category. Then we found
16SrRNA complete sequences for same species. After that, based on the Average Alignment
Score (AAS), the 16S-taxonomic tree was obtained. Furthermore, Similar calculations were
considered for corresponding RecA proteins phylums.
Results: By comparing amount of AAS in 16SrRNA phylums and RecA phylums, we
observed that the Actinobacteria phylum is the closest to the header phylum in the 16Staxonomy
tree, but this phylum in the RecA is the most distant to the header phylum, on the
other hand, the position of the cyanobacteria phylum remains the same in both calculations,
which indicates the least amount of changes in the genus and species of this phylum.
Conclusion: The 16S-taxonomy tree which has been compiled and presented in this study
for the first time is different from the available bioinformatics algorithms for phylogenetic tree
drawing. Finding the species with the highest and lowest rates of changes, can be a type of
prediction method for indicating the reasons why bacteria become resistant to drugs over a long
period of time.
Background and Aims: The purpose of this study was to investigate the possibility of Listeria monocytogenes entering the VBNC state during the frozen storage and the expression of its pathogenic genes
Materials and Methods: Bacteria in 106 Colony counts of in mid log phase were inoculated into three Culture medium including Normal Saline (NS), BHI Broth and Fish Broth (FB) and kept at -18ºCfor 2 months and examined. Then, bacteria were evaluated on enriched medium BHI agar using culture methods (colony count) over times 4 and 8 hours, 2, 4, 8, 20, 30 and 60 days after the freezing shock using the method of RT-PCR for investigating the expression of 16S rRNA, hly and inlA genes; they were evaluated before and after the freezing shock.
Results: This bacterium retained its ability to cultivate until the end of the shock, but reduced its number. Freezing stopped the expression of genes of hly and inlA, as these genes were not expressed in a rich culture medium either. By adding blood to the rich culture medium of this bacterium, only the hemolysin O pathogen gene was expressed.
Conclusion: Although freezing does not lead to the introduction of this bacterium into the VBNC state, it is effective as an adverse environmental factor for the bacteria in the expression of its pathogenic genes. Blood and its agents can act as an agent for the induction and clarification of the hly gene, and the expression of pathogenic bacterial genes are independent of each other.
Background and Objective: Recently, coronavirus has become a major cause of death and hospital admission worldwide. This study was aimed to assess the factors associated with the presentation via ambulance and time to in-hospital death or discharge from the hospital using a multilevel joint modeling approach.
Materials and Methods: In this historical cohort study, hospitalized patients with COVID-19 were included from 34 medical centers in Khuzestan province, Iran, from February 18th, 2020, to January 5th, 2021. Joint model analysis was used to assess the impact of demographic and clinical characteristics on the mode of hospital presentation and time to death/discharge from hospitals in Khuzestan province, Iran.
Results: Among 22,356 patients, 14.2% presented to the hospital via ambulance, and 11.2% died in the hospital. The odds of ambulance use was higher in patients with older age, male sex, comorbidities including respiratory disease, diabetes, cancer, and drug abuse, and symptoms such as respiratory distress and loss of consciousness. Older age, male sex, a higher burden of comorbidities, symptoms of chest pain, respiratory distress, and loss of consciousness, and admission to intensive care unit were predictors of in-hospital mortality. The median survival time was longer for patients with COVID-19 who self-presented to the hospital compared to those who presented with ambulance (31 vs 20 days; log-rank P
Background: In the outbreak of infectious diseases, non-pharmacological intervention might be the only available protection tools. The aim of this systematic review is to investigate whether it is or is not necessary to wear masks in new corona virus (COVID-19) outbreaks in the community.
Methods: On February, 28, 2020, related databases were searched with the following keywords: "COVID-19"; "COVID 19"; 2019-nCoV; 2019-CoV; coronavirus; mask* and facemask. We updated the search in March 13, 2020. A total of 982 relevant reports were identified after removing duplicates. Of these, 71 references were screened based on titles and abstracts. After excluding unrelated studies, 36 studies were included in the full-text review and were assessed for eligibility. Finally, 3 articles met our inclusion criteria.
Results: In three wards of hospital with more exposure to infected patients, wearing the N95 respirator while using regular disinfectants and hand hygiene, was a better way to prevent COVID-19 transmission from patients to nurses and physicians when compared to non-users of masks. Another study on family members with a history of travelling to Wuhan, showed that those who had worn a surgical mask only during the hospital visit, were infected. However, the 7 years old child of the family who wore a surgical mask, was not found to be infected by COVID-19. Finally, none of eleven healthcare workers who had unprotected exposure with confirmed cases were infected.
Conclusion: Due to the newness of the COVID-19 virus, no clinical trials have been found regarding the use of the masks in the prevention of the disease, and the level of evidence were low.
The 2019 novel coronavirus is another type of known coronaviruses; SARS-CoV-1 and MERS-CoV. The World Health Organization (WHO) has named the virus SARS-CoV-2 and its disease as coronavirus disease 2019 (abbreviated COVID-19). The first case of COVID-19 was reported in December 2019 in Wuhan, China. The epidemiological studies have shown that the disease is transmitted from animal to human, and the spread of the disease from person to person is rapidly expanding. Currently, the most important factor in preventing and controlling the spread of the disease is proper recognition, health care, and control measures. Given the importance of early detection and timely treatment of the disease, the use of nanoscale materials for the production of sensors and drug delivery system can be of great assistance to the researchers. In this context, we aimed to explain the effects of the prevalence of the disease worldwide and consider the different aspects of SARS-CoV-2.
Background and Aim: SARS-CoV-2 is the causative agent of Coronavirus 2019 or COVID-19 in the world. Novel coronavirus disease is a respiratory disease. To date, there have been challenges in the treatment for COVID-19 and emerged new variants like UK B1.1.7. Accordingly, an effective prevention regime is needed for this infection, which covers most variants. The purpose of this research was to predict the conserved epitopes of Spike and Nucleocapsid proteins from SARS-CoV-2 for the design of a novel coronavirus 2019 multi-epitope vaccine using in silico tools.
Materials and Methods: Computational analysis and immunoinformatics approaches include identification of potential conserve epitopes and selection of epitopes based on allergenicity, toxicity, antigenicity, and molecular docking were used for epitope prediction and screening. In the next step, selected segments of the epitopes were attached by the suitable linkers. Finally, Maltese-bound protein (MBP) as an adjuvant was added to the novel vaccine structure. The secondary and third structures of the designed multi-epitope vaccine were predicted via immunoinformatics algorithms. Predicted structure refined and validated for attaining best stability. In the end, immunoinformatics evaluation, molecular docking, and molecular dynamics were performed to confirm vaccine efficiency. Codon optimization and in silico cloning were done to ensure the expression yield of the novel multi-epitope vaccine in the target host.
Results: This study showed that our data support the suggestion that the designed vaccine could induce immune responses against SARS-CoV-2 variants.
Conclusion: The structure designed had acceptable quality with software reviews. Further in vitro and in vivo experiments are needed to confirm the safety and immunogenicity of the candidate vaccine.
Coronavirus infection is nowadays a major public health issue which affected societies and economics worldwide. It is therefore necessary to attempt to conduct research to find how the disease affect the human health. In this regard, the Student Research Committees (SRC), subdivision of research vice-chancellor of Iranian Universities of medical sciences have effectively contributed to provide suitable platform for medical students to learn how to conduct scientific researches. The purpose of this study is to evaluate the studies conducted by student research committees in the field of Covid-19 because Covid-19 is currently one of the most fundamental health issues in the world as well as in our country. This field can increase students' ability to solve problems and gain experience to deal with health challenges and problems. According to the scientometrics system of SRCs of medical universities of the country, the research activity of the SRC of Shahid Beheshti University of Medical Sciences has always been growing, which shows the increased motivation and spirit of cooperation among students of this university in the field of research. In this context, programs and progress of Shahid Beheshti University of Medical Sciences SRC can be considered as a model for other universities to focus on the potential and capability of young student researchers to deal with these concerning health challenges and issues.
Background and Objective: Coronavirus disease known as COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is affecting over 200 countries all over the world. This study was aimed to identify simple and swiftly available laboratory biomarkers to help facilitate effectual triage to categorize suspected COVID-19 patients.
Materials and Methods: According to a standard protocol, we collected clinical, etiological, and laboratory data of 140 patients who underwent diagnostic tests at Medical Laboratory Group, Tehran, Iran, from October 1 to November 28, 2020, based on PCR testing for SARS-CoV-2 infection. Leukocyte parameters, C-reactive protein (CRP) and, ferritin levels were measured in patients with positive PCR COVID-19 test.
Results: 140 patients with COVID-19 infection were included in the study. The median age in women was 41.5 (23-60) years and 45.3 (22-68) years in men. Based on RT-PCR result, there were significant differences for neutrophil, lymphocyte, and monocyte counts. Overall, 72.8% of patients had monocyte count more than 11 ×109 /L. The mean neutrophil lymphocyte ratio (NLR) for women was 2.8 (SD: 1.8) and 2.6 (SD: 1.7) for men. Only in 15 patients (10.7%) with respiratory symptoms, CRP level was more than 5 mg/L.
Conclusion: We found a significant increase in monocyte count. Lymphopenia was also observed. In patients with respiratory symptoms, CRP was significantly higher than the normal reference range.
The Coronavirus disease 2019, identified by Chinese researchers to be the caused by a novel enveloped betacoronavirus, Severe Acute Respiratory Syndrome Coronavirus- 2 which was first isolated in Wuhan, China has been declared a global pandemic by the world health organization. The virus has several structural proteins that contributed to its pathogenesis such as spikes, membrane, envelop and nucleocapsid protein facilitating its attachment, entry and cell-to-cell transmission. The virus is readily transmitted through human-to-human contact and there is presently no approved vaccine for its prevention. This study was carried out to review the epidemiology of Severe Acute Respiratory Syndrome Coronavirus- 2, its host and reservoir, pathogenesis, transmission, clinical manifestation and potential treatment options for the infection.
Background and Aims: Hydatidosis is one of the most important zoonotic parasitic diseases. Hydatidosis is endemic in Iran and is the cause of hospitalization of almost 1% of patients in surgical wards. The purpose of this study is to examine the epidemiologic status of hydatid cyst in patients undergoing surgery in Golestan hospital of Ahvaz during 2002-2011 using archived files of the patients.
Materials and Methods: This research is a cross-sectional study. During the mentioned period, 2002 until 2011, 55 patients in Ahvaz Golestan hospital have undergone hydatid cyst surgery and the information in the patients' files were examined by referring to the relevant archives in the mentioned hospital.
Results & Conclusion: Among the 55 patients studied, 37 (67.3%) were female and 18 patients (32.7%) were male. The highest incidence rate was found in liver with 47 cases (85.5%), followed by lung with 5 cases (9%). Considering the results, the highest prevalence rate was found among urban residents (n=33 ,60%) whilst 22 cases(40%) belonged to the rural residents. The results of this study indicate that the occurrence of the disease was significant in Khuzestan province during the mentioned period which reflects the necessity of more comprehensive and updated studies.
Background and Aims: Staphylococcus aureus is the most common and important nosocomial pathogens and due to potential virulence and increasing resistance to anti-microbial medicines, they become one of the most important health problems through worldwide. So the aim of this study was identification and characterization of S. aureus resistant to Methicillin and Vancomycin from patients hospitalized in Razi hospital of Ghaemshahr and Shahid Zare of Sari and characteristics antibiotics susceptibility pattern in 2015.
Materials and Methods: In this cross-sectional descriptive study, 134 strains of Staphylococcus aureus from hospitalized patients in infectious diseases and burns were collected randomly from the hospital laboratory and transferred to the research laboratory. The specimens were incubated in Blood Agar medium for 24 hours at 37 ° C. The colonies were examined for morphology, biochemical properties, resistance to polymixin and sensitivity to Novobiocin. For isolates, antibiotic test was performed using disk diffusion method and PCR detection was performed. PCR results were approved for sequencing.
Results: 100 out of 134 samples were positive for S. aureus; 51 samples were methicillin-resistant and 2 samples were resistant to all of the antibiotics and Vancomycin with vanA and vanB resistance gene.
Conclusions: Determination of new resistance factor in nosocomial infection is one of the major challenges in treating these infections. 25.37% of the samples, weren’t S. aureus. This study showed 51% prevalence of methicillin-resistance.
Background and Aims: Chickenpox is a highly contagious disease caused by infection with Varicella Zoster Virus (VZV). Although it is usually a self-limited disease, but severe complications may occasionally occur. The aim of this study was to investigate the seroprevalence of VZV antibody among students of Babol University of Medical Sciences especially female students in reproductive age.
Materials and Methods: 270 students were enrolled to our study. After signing a written informed consent, demographic data and 5 ml blood sample were collected from each participant. Following serum isolation, each serum sample was assessed by ELISA technique for VZV IgG.
Results and Conclusion: Of two hundred and seventy students, 197 were female and 73 were male. Out of female students, 145 students (73.6%) were single and in reproductive age. 17.3% of female students and 8.2% of male students were seronegative and susceptible to VZV infection. Besides, 7.9% of unmarried male students and 20.7% of unmarried female students were susceptible to VZV infection. The highest susceptibility to VZV was seen in 18-21 years age group. Therefore, more than 20% of unmarried female students were susceptible to VZV, which can be important regarding infection during pregnancy and subsequent severe complications. Consequently, vaccination for VZV in susceptible students especially unmarried female students is recommended.
Background and Aims: Helicobacter pylori is the main cause of various gastroduodenal diseases. It is estimated that app roximately, more than half of the adult population in developed countries and 90% of people in developing countries infected with H. pylori. H. pylori infection may be related to Genetic of virulence factors and environmental factors. The aim of this study was to assess of frequency cagA and vacA genes of H. pylori isolated from patients with Gastrointestinal Disorders.
Materials and Methods: This cross-sectional descriptive study carried out on 120 patients with gastrointestinal diseases in Gorgan city in 2017. (40 patients of gastric cancer, 40 patients of peptic ulcer, 40 patients of without cancer and ulcer). After genomic DNA extraction PCR was carried out using specific H.pylori primers.
Results: Overall, 120 H.pylori strains were isolated. The frequency of cagA was %67.5 in gastric cancer, %60 in peptic ulcer and %45 in patiens without ulcer and gastric cancer. Also frequency of vacA gene was detected %55 in gastric cancer, %40 in peptic ulcer and %27.5 in patiens without ulcer and gastric cancer.
Conclusion: Based on our findings it seems that the cag A and vac A genes were virulence among H. pylori isolated from studied patients. The frequency of cagA and vacA genes H. pylori were than in gastric cancer and peptic ulcer patients.
Background and Objective: Acinetobacter has been considered an important nosocomial pathogen since 1970. This study aims to investigate the prevalence of Acinetobacter infection during 2017-2021, study the antibiogram of these bacteria, and study the impact of gender on infection.
Materials and Methods: This is a retrospective study in which data of the clinical samples received in Al-Kafeel Hospital, Kerbala, Iraq, between April 2017 and February 2021 were searched for Acinetobacter infection and their antibiotic susceptibility testing.
Results: The prevalence of Acinetobacter infection was 9.2% of cases. Male to Female ratio was 3:1, and there was a significant difference in Acinetobacter infection regarding gender. There were high resistance rates to major antibiotic classes. Maximum resistance was recorded for Amoxicillin (100%), followed by 3rd generation cephalosporins, including Cefotaxime (92.3%), Ceftriaxone (91.6%), Ceftazidime (91.3%), Cefixime (80%); in addition to growing resistance to carbapenems, Imipenem (42.8%) and Meropenem (62.2%). The lowest resistance rates were found to colistin sulfate (10%). There 80.7% of the isolates were multidrug-resistant MDR.
Conclusion: Acinetobacter spp., is considered as fast emerging opportunistic agents with evolving drug resistance. Rationale use of antibiotics is important and necessary to prevent microbial resistance. Gender is considered a risk factor for Acinetobacter infection.
Background and Objective: Acinetobacter baumannii is considered to be a re-emerging causative agent of nosocomial infections. There is a significant relation between pathogenicity of this bacterium and the numerous virulence factors. The purpose of this study was to investigate nine virulence factor genes in A. baumannii isolates derived from hospitalized patients.
Materials and Methods: A total of 50 A. baumannii isolates were recovered from patients with pneumonia in Imam Khomeini Hospital, Tehran, Iran. Following biochemical and microbiological identification of the bacteria, Multiplex PCR was performed for basD, plD, csuA genes, surA, pbpG, bfmR genes, and bap, ompA genes using specific sets of primers which were specifically designed for this study. The espA was identified separately by a Uniplex PCR assay. All amplified DNA fragments were sequenced for the products’ confirmation.
Results: Among the 50 clinical isolates of A. baumannii studied, bfmR and pbpG genes were reported in all samples (100%), bap, plD, surA, and csuA genes were collected from 49 samples (98%), 48 (96%) of these isolates had ompA and basD genes, and espA gene was observed in only five isolates (10%).
Conclusion: According to this study results, virulence factors genes in clinical A. baumannii have a prevalence rate more than 90%. Additionally, the high incidence rate of those genes related to biofilm formation indicates that most clinical strains have the ability to form biofilm structures.
Background: Regarding the availability of an effective vaccine against hepatitis B virus, global vaccination is the best cost-effective strategy to prevent HBV infection. However, some people may not respond to the vaccine or the titer of antibody decreases by time. Therefore, the present study aimed to determine the frequency of anti-HBs antibody (anti-HBsAb), among university students in Fars province, southern Iran.
Methods: In this cross-sectional study, 825 medical students were enrolled. Blood samples were taken from the subjects, and the serum separated and stored at – 20 ºC until use. Next, HBs Ab titer was measured by ELISA method.
Results: Out of 825 students 54% was male and 46% were female. The mean age of the students was 19.5±1.9. The titer of anti-HBsAb in 529 (64%) of subjects was lower than 10 mIU/mL. Significant relationship was observed between age and the titer of anti-HBsAb (P=0.001), although no significant relationship was observed between gender (P=0.19), history of blood transfusion (P=0.58) and the titer of anti-HBsAb.
Conclusion: Finding of this study showed that the titer of anti-HBsAb in more than half of students was lower than 10 mIU/mL and by time the anti-HBsAb titer decreased, indicating the necessity of measurement of anti-HBsAb titer in medical students.
Background and Aims: Salmonella Spp. is one of the most common causes of bacterial gastroenteritis and foodborne diseases. More than 2500 serotypes of Salmonella have been identified which most of them cause infections in humans.
Phylogenetic analysis of the family Enterobacteriaceae has not been subjected to extensive variation based on 16S rRNA sequences. In fact 16S rRNA gene was not thought to solve taxonomic problems concerning closely related species because of its highly degree of conservation in own structure. So, 23S rRNA gene which has a potential to classified related strains under sub-species level were candidate to analysis of Salmonella spp.
The aim of this study was to evaluate the clinical Salmonella strains’ relationship using
23S rRNA gene sequence.
Materials and Methods: DNA of identified Salmonella spp. from patients with acute diarrhea was extracted. Sequences of 23S rRNA were determined after PCR tests. The whole gene sequences were used to generate phylogenetic trees based on Neighbor-joining method by MEGA 5.05 5.
Results: Helix (25 and 45) structures were detected in the most of different serotypes isolates. All S.Typhi included helix-25 in ribosomal structure, but in the other strains, helix-45 was also observed. The similarity between Salmonella spp. was 99-100% based on 23S rRNA.
Conclusions: 23S rRNA gene sequence data was better to analyze at subspecies level and differentiation between serovars. According to variety in Salmonella serotypes based on difference in Anti gene O and H, application of new molecular methods and substituting them with traditional assays are needed.
Background: Acinetobacter baumannii is a non-fermentative gram-negative coccobacill that has high level of resistance to antimicrobial agents. Biofilm formation is an important feature of most clinical isolates of Acinetobacter spp, this led to higher resistance to antibiotics. The current study aimed to assess the ability of biofilm production and to determine the frequency of bap gene in clinical isolates of Acinetobacter baumannii.
Materials & Methods: This descriptive cross-sectional study was performed on 165 strains collected from hospitals of Tehran in 2019 and confirmatory tests were performed to identify the bacteria. The antibiotic resistance pattern of the isolates was determined by disk diffusion method against 10 antibiotics and also the ability of biofilm production was evaluated by microtiter plate method (MPT) and tube method (TM). Subsequently Molecular assays of blaOXA-51 and bap genes identification and its frequency were investigated.
Results: In this study, among 165 isolates examined, 73 isolates were confirmed as Acinetobacter baumannii. Among 73 strains studied the most antibiotic resistance was imipenem (94.52%). blaOXA-51 and bap genes were detected in 100% and 53.42% of isolates. Also, 8 isolates (10.95%) by MTP and 7 isolates (9.58%) by the TM method were able to form strong biofilm.
Conclusion: The results obtained showed that in consistent with other researches, biofilm formation in Acinetobacter baumannii isolates was associated with present of bap gene.
Background: Dermatophytes are common causes of cutaneous infections in humans and animals, which mostly reproduce by an asexual process. Such types of reproduction in many filamentous fungi are usually regulated by brlA, abaA, and wetA genes. The presence of these genes in dermatophytes was investigated.
Materials & Methods: Conidiation genes represented by brlA, abaA, and wetA were determined in seven strains of dermatophytes using a polymerase chain reaction (PCR) method.
Results: All strains of Microsporum canis and one strain of Microsporum ferrugineum (MH383043) were shown to have all three specific conidiation genes, which were absent in other strains, except for Trichophyton interdigitale which had only the abaA gene.
Conclusion: Dermatophytes content of brlA, abaA, and wetA genes is variable and strain-dependent. The conidiation process in most dermatophytes is assumed to be under the control of other genes not included in this study.
Background and Aims: Microbial detoxification is one of the methods for eliminating of aflatoxins, including aflatoxin M1. Reports indicate that some strains of lactic acid bacteria family through surface adsorption of aflatoxin in their cellwall can be effective in removing them and as a primer culture. In this study, the ability of Bifidobacterium animalis and Lactobacillus delbrueckii in the adsorption of aflatoxin M1 in skim milk was assessed.
Materials and Methods: For this purpose, about 108 and 109 cfu/ ml of B. animalis (Lactis) and L. delbrueckii (Blegaricus) were inoculated into skim milk without aflatoxin M1. Then, the samples were spiked by aflatoxin M1 in concentrations of 0.25, 0.5 and 0.75 ng/ ml. The concentration of the aflatoxin reside in supernatant of milk samples after different storage times (0.5, 1, 2 and 24 h) and temperatures of 4 and 37°C was measured by ELISA method, and the results were confirmed by HPLC.
Results: The results showed that the highest amount of aflatoxin M1 removal was respectively related to B. animalis (60 ± 2.5%) with a concentration of 108 cells/ ml and L. delbrueckii (58.5 ± 2.5%) with a concentration of 109 cells/ ml and a concentration of 0.5 ng/ml poison at 37°C for 30 minutes. By comparing the concentration of both bacteria, it also appeared that the B. animalis concentration at 37°C and L. delbrueckii concentration at 4°C were more effective. Also, the results indicate that the ability of bacteria to reduce the amount of poison in half an hour in milk samples with values of 0.75 ng/ml poison at 4°C and 0.5 ng/ml poison at 37°C is higher; but over time, contaminated milk at a concentration of 0.75 ng/ml poison compared to 0.5 ng/ml poison showed an increased amount of aflatoxin removal.
Calclusion: B. animalis and L. delbrueckii can act as two useful probiotics to reduce the harmful effects of aflatoxin M1.
Background and Aims: The monitoring of the causative agents of nosocomial infections (Nis), particularly in the Intensive Care Unit (ICU) ward to detect any change in pattern of infection and their resistance profile are crucial. The aim of this study was to investigate the antibiotic resistance pattern among Gram-negative rods isolated from inpatients in different wards of ICU in Shiraz, Iran.
Materials and Methods: In this cross-sectional study from Jaunary to June 2017, 91 different clinical samples were collected from Nemazi teaching hospital ICU wards. After confirming all the isolates by the conventional microbiologic methods, their antimicrobial susceptibility pattern against 11 antibiotics were investigated using the disk diffusion test. Extended-spectrum β-lactamase (ESBL) production was also examined.
Results and Conclusions: The isolated bacteria were Acinetobacter baumannii (n=72, 79.1%), Pseudomonas aeruginosa (n=14, 15.4%), and Escherichia coli (n=5, 5.5%). The highest and the lowest resistance rates were observed against ampicillin (100% and 95.8%) among P. aeruginosa and A. baumannii and imipenem and amikacin (0%) among P. aeruginosa and E. coli isolates, respectively. The frequency of multidrug-resistant (MDR) and ESBL-producing isolates was found 84.6% and 19.8%, respectively. Of the MDR isolates, 23.4% were ESBL producers. A significant difference was determined between ESBL production and MDR isolates.
Regarding the high rate of antimicrobial resistance among clinical isolates in the study area, the antibiotic susceptibility results may be a useful guide for empirical therapy used by physicians.
Background and Aims: Acinetobacter baumannii is a major cause of nosocomial infections and is resistant to many antibiotics. Over expression of AdeABC and AdeIJK efflux pumps in Acinetobacter causes resistance to aminoglycosides and decreases the sensitivity of fluoroquinolones. The aim of this study was to investigate the phenotypic activity of the Acinetobacter baumanni isolates associated with presence of adeA, adeB, and adeI genes.
Materials and Methods: The study was performed on 55 strains of A. baumannii isolated collected from specimens of patients hospitalized in Milad Hospital , Tehran. The isolates were diagnosed using biochemical tests and antibiotic susceptibility testing was done by disk diffusion method based on CLSI guidelines. Cartwheel method was used to study phenotypic activity of efflux pump. Multiplex PCR was used to determine the presence of genes.
Results: The prevalence of multiple drug resistant isolates was 98%. In terms of efflux pump activity 3.63% isolates were strong, 67.27% moderate and 29.09% were non-active. The frequency of adeA, adeB, adeI genes was 87.2%, 85.4% and 94.5%, respectively. There was significant association between adeA and adeB genes among isolates with actively and non-actively efflux pump.
Conclusions: Determination of actively phenotype of efflux pump can determine the multiple drug resistance among A. baumannii isolates. The results confirms the role of main genes encoding AdeABC operon,adeA and adeB in activity of A. baumannii efflux pump.
Background: Acinetobacter baumannii is one of the most common challenging pathogens in causing serious infections in intensive care units of modern hospital systems around the world and poses a serious threat to public and patient health. This study aims to analyze the network of scientific and empirical collaborations of A. baumannii researchers in the last three decades. Materials & Methods: The present study was performed using the Co-citation analysis technique. All A. baumannii publications indexed on the Web of Science Core Collection for the period 1990-2019 are the statistical population of the study. After an advanced search, 4473 documents were retrieved. A total of 18343 authors contributed to the publication of the retrieved documents. Ravar PreMap 184.108.40.206, NetDraw, and UCINET 6.528.0.0 software were utilized for data analysis. Results: Data analysis showed that the global publication of A. baumannii has risen. "Clinical Infectious Diseases," was the best journal, and "Seifert, Harald," the most influential researcher, and "Seifert, Harald * Higgins, Paul G," were identified as the best co-citation pair. Top researchers in A. baumannii were "Beceiro," "Alejandro," "HSU Li Yang," and "Seifert, Harald," respectively, based on degree, betweenness and closeness centrality indicators. Conclusion: Analysis of social networks A. baumannii presents an objective and realistic view to experts and planners in Medical Sciences. Also, the structure of A. baumannii's internal relationships and researchers' connections is determined objectively. Finally, researchers get acquainted with journals, scientists and organizations that are proliferated and effective and plan to collaborate with them in the future
Keywords: Acinetobacter Baumannii; Co-citation analysis, Social network analysis; Scientometrics; Bibliometrics
Background and Aims: Pharmaceutical residuals like antibiotics in livestock products and their consumption by humans from food chain can lead to the spread of bacteria resistant to antibiotics. The aim of the current study was to investigate antibiotic resistance and determine the prevalence rate of genes encoding extended spectrum beta-lactamase (ESBLs) in Acinetobacter strains isolated from raw foodstuffs.
Materials and Methods: In this study, 300 samples from protein foodstuffs (mutton, beef, chicken, hamburger, hot dog, sausages) and dairy foodstuffs (raw milk and cheese) were prepared and investigated in terms of contamination with Acinetobacter baumannii from July 2015 to November 2016. The isolated bacteria were identified by biochemical tests to species level and confirmed by the PCR technique via blaOXA-51 gene. Antibiotic resistance of the isolates was studied using the diffusion disc method. Also, the presence of ESBLs enzymes in the isolates wa s done phenotypically and genetically through PCR and combined disk tests.
Results: The results showed that 43 strains of A. baumannii were isolated from the protein and dairy foodstuffs, 93% from protein foodstuffs and 7% from dairy foodstuffs. Also, 30% of the isolates had multidrug- resistance (MDR). Further, the findings of PCR illustrated that the prevalence of genes encoding ESBLs in the isolates were: TEM 21%, PER 23.5%, VEB 18.5% and SHV35%.
Conclusions: Foodstuffs can act as a food source for A. baumannii that can lead to transferring and spreading genes encoding antibiotic resistance to humans.
Background and Aims: Flow cytometry is a rapid method that can analyze thousands of cells per second and can be used for determination of microbial populations and determination of bacterial antimicrobial susceptibility. In this study antibiotic resistance pattern of Acinetobacter baumannii isolates by flow cytometer was evaluated.
Materials and Methods: 55 isolates of Acinetobacter baumannii were isolated from clinical specimen of patients and were identified by biochemical tests. Antibiotic resistance patterns were studied by disc diffusion method and MDR strains were selected. MIC of Meropenem and Piperacillin were determined. Also antibiotic resistance pattern of isolates was determined by coloring with Rhodamine-123 and flow cytometry.
Results: 98% of isolates were MDR. The MIC ranges for maropenem were 8 - 256 μg/mL and for piperacillin were 128-1024 μg/mL. By flow cytometry it was demonstrated that at concentrations of 8, 4 and 2 μg/mL of meropenem, only 1.96%, 1.44% and 0.59%, of cells were killed respectively. At concentrations of 64,128 and 16 μg/mL of piperacillin, 13.8%, 11.3% and 5.9%of cells were killed respectively. Reducing the number of living bacteria was observed with increasing concentrations of both antibiotics.
Conclusion: The similarity between the results of flow cytometry and both agar and broth antibacterial susceptibility methods showed flow cytometry as a reliable and rapid test that can be used for this purpose.
Background and Objective: Moraxella catarrhalis a gram-negative bacterium, is a significant cause of lower and upper respiratory infections. The RND family efflux pumps lead to multidrug resistance in gram-negative bacteria. One of the well-known pumps in M. catarrhalis is AcrAB-OprM system. This study aimed to investigate the antibiotic resistance in M. catarrhalis and to determine its antibiotic resistance dependence on the efflux pump.
Methods: In this study, 137 different clinical samples were collected. M. catarrhalis isolates were confirmed by biochemical assays and PCR. The antibiotic susceptibility pattern was investigated by disc diffusion method according to CLSI. Phenotypic study of the efflux pumps activity was done using cartwheel method. Study of the acra, acrb, and oprm genes were performed by, PCR. In addition, the association of efflux pump with antibiotic resistance was investigated using phenylalanine-arginine β-naphthylamide.
Results: Of 10 isolated M. catarrhalis, 70% (7 isolates) showed multiple antibiotic resistance. The resistance to cefazolin, ceftazidime, tetracycline, chloramphenicol, and ciprofloxacin antibiotics was also dependent on the efflux pump.
Conclusion: The results showed that multiple antibiotic resistance has increased in Moraxella catarrhalis. The 70% presence of acra, acrb, oprm efflux genes of the efflux pumps in this bacterium and antibiotic resistance reduction in the presence of efflux pump inhibitor shows the importance of examining these genes’ presence to suggest a suitable treatment model for the patients infected with M. catarrhalis.
Background and Aims: Marine Actinomycetes are gram-positive bacteria that sometimes are free, saprophytic or plant and animal-associated, including marine sponges. More than 75% of antibiotics and antimicrobial compounds are produced by actinomycetes. In recent years, due to the need for new drugs, marine microorganisms have been considered as new sources of potential production of significant metabolites. The purpose of this study is isolation and identification of marine sponge-associated Actinomycete and investigation of its antibacterial activity.
Materials and Methods: The Actinomycete was isolated from the marine Sponge collected from the depths of coastal waters in Bushehr and screened for antibacterial activity on pathogenic microorganisms of Escherichia coli، Bacillus cereus، Klebsiella spp.، Salmonella spp. and Proteus spp. using a Disk Diffusion Method. For molecular identification, genomic DNA was first extracted from isolate and then, the16S rDNA gene was amplified by PCR and Sequenced. The results were analyzed using bioinformatic programs, Bioedit and MEGA6.
Results: In this study, based on phylogeny studies, it was determined that the isolate belonged to thegenus Streptomyces, and biochemical studies showed that all tests except catalase and gram were negative; antibacterial activity study showed significant activity against three pathogenic bacteria, E. coli, Bacillus cereus and Salmonella spp. It was more active against Salmonella spp. (around 16mm inhibition zone diameter).
Conclusions: The results showed that depths of the Bushehr coastal waters have marine sponge associated actinomycetes, which are a source of secondary metabolites with biological activity.
Background: The current study was aimed to evaluate the antibacterial and antioxidant activities of some Saudi Arabia honey products. Methods: For this investigation, sixty Saudi Arabia honey products were tested to determine the antimicrobial activity against highly antibiotic-resistant pathogens as well as antioxidant activity in comparison with Manuka honey as a standard. Results: Testing Saudi Arabia honeys, different levels of growth suppression were observed against five bacterial strains. The pathogenic strains were Staphylococcus aureusas, Escherichia coli, Proteus vulgaris, Citrobacter diversus and Salmonella enterica. These suppression levels depended on the type of honey. The comparative study of Saudi Arabia honeys revealed a strong correlation between total polyphenol and flavonoid contents and significant radical scavenging activities. Conclusion: It was concluded that Saudi Arabia honey products have the capacity to suppress the growth of pathogenic bacteria and perform significant radical scavenging activities. Keywords: Antibacterial activity, Antioxidant activity, Saudi Arabia honey
Background: One of the medicinal fungi that has been used in traditional medicine for a long time is the Basidiomycete fungus Fomes fomentarius, which is widely distributed in Iran. Polysaccharides as one of the metabolites of this fungus have anti-inflammatory, anti-diabetic, antibacterial, antioxidant, and anti-cancer properties.
Materials & Methods: Optimization of independent variables of MgSO4.7H2O concentration, initial pH, yeast extract, and inoculum percentage to increase biomass and polysaccharide production of F. fomentarius was investigated using the Taguchi method. Then, the biological properties of the produced polysaccharide including antibacterial activity was investigated by bacterial colony counting method, antioxidant activity using DPPH free radical, and antiproliferative effect on 5 cancer cell lines MKN-45, AGS, A549, KYSE-30 and 5637 using MTS test.
Results: The concentration of MgSO4.7H2O and initial pH had a significant effect (P A549 5637> AGS> MKN-45). This effect increases with increasing concentration. In KYSE-30 cell line treatment with 200 g/mL polysaccharide, cell viability reaches 40% after 72 hours.
Conclusion: Optimizing the culture medium of the medicinal fungus Fomes fomentarius increases the production of polysaccharides up to 5.410 g/L. Optimization increases the biological activity of polysaccharides. Antibacterial activity against Staphylococcus aureus and Escherichia coli is 50% and 25%, respectively. The antioxidant activity of polysaccharides is 16.11% and the viability of KYSE-30 cancer cells reaches 40% after 72 hours.
Background and Aim: Bacterial enteritis occurred in neonatal lambs, is an economically important disease that can cause high morbidity and mortality in lambs, therefore, emergency antibacterial treatment is necessary. Malva sylvestris L. plays an important role in traditional remedies for medicinal properties. The present study aimed to evaluate the antibacterial activity of M. sylvestris on bacterial pathogens isolated from the stool of diarrhetic lamb.
Materials and Methods: The antibacterial activities of M. sylvestris hydroalcoholic extract (MSHE) were evaluated by agar diffusion and microbroth dilution methods against isolates of Salmonella enterica (n=10), Escherichia coli (n=10) and standard strains S. enterica PTCC 1709-CIP104115, E. coli PTCC1270.
Results & Conclusion: The results of plant extract efficiency against clinically isolated reported as Minimum Inhibitory Concentration (MIC) test and Minimum Bactericidal Concentration (MIC) test toward E. coli (MIC: 11.56±0.0 mg×mL-1 and MBC: 21.25±0.0 mg×mL-1) S. enterica (MIC: 42.50±0.0 mg×mL-1 and MBC: 80.00±0.0 mg×mL-1). The conclusions of this study indicated that M. sylvestris revealed antibacterial properties and this plant could be a good candidate for the generation of new wide spectrum antibacterial agents.
On December 31, 2019, pneumonia due to the severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2, formerly known as 2019-nCoV) appeared to Wuhan, China, and COVID-19 is an infectious disease caused by SARS. CoV-2. SARS-CoV-2 is a new strain of coronavirus that has not been previously identified in humans. Until April 18, 2020, 2275783 were confirmed and 156104 deaths worldwide reported. This paper presents an overview of the findings that scientists have realized so far. In this study articles indexed in Embase, Elsevier, PubMed, Google Scholar and using keywords SARS-CoV-2, COVID-19, Coronavirus 2019 and nCoV-2019 were used. The World Health Organization and the Centers for Disease Control and Prevention used the world's most reputable websites to obtain the latest COVID-19 disease statistics. In the initial search, 500 articles were extracted and 55 articles were selected after duplication and evaluation of title and abstract. The results show that the mortality rate of the virus in the elderly and people with underlying diseases is significantly higher than in the healthy ones. High-risk groups for the disease include cardiovascular disease, diabetes, chronic respiratory disease, and hypertension, respectively. The novel coronavirus pandemic is more widespread in humans compared to previous coronaviruses, which indicates the extremely high prevalence of the virus. No vaccine or cure has been found for the virus so far, but supportive treatments and early diagnosis are effective in the treatment process, and there are many treatments around the world for the treatment of COVID-19.
Keywords: COVID19|SARS-CoV-2|2019 novel coronavirus disease|COVID-19 pandemic ,
Background and Objective: Wound healing is the result of interactions between cytokines, growth factors, blood, and extracellular matrix. Facing this challenging issue has become one of the essential concerns in health and medical fields, needing different remedies. One of the newest treatments in wound healing is the application of probiotic bacteria. Therefore, the aim of the current study is to evaluate the effect of Bifidobacterium bifidum probiotic bacteria on acute wound healing and exploring the potential of their supernatant on increasing angiogenesis in female mice in the form of biological dressing.
Materials and Methods: 44 female BALB/c mice were studied into six groups in two phases of 7 and 14 days. After the wounding process, wound sizes were measured by a digital caliper every 48 hours. Mice were dressed and treated. Histological samples were studied, and the results were analyzed statistically.
Results: Bifidobacterium bifidum probiotic bacteria not only show exciting potential as a therapeutic and effective agent but also our examination proved that application of this probiotic plus Aloe vera hydrogel (experimental group 1) can significantly reduce the wound healing duration and increases angiogenesis (P
Background and Aims: Diarrhea caused by intestinal bacteria is a major cause of mortality, especially in children under the age of five in developing countries. Vaccines can be considered as an important solution to prevent these diseases. Toxin-coregulated pilus (TcpA), OMPW and cholera toxin are the most important virulence factors of vibrio cholera and have immunogenic characteristics. In this study, a recombinant immunogen consisting of TcpA, Outer Membrane Protein OMPW, and cholera toxin B-subunit (CtxB) was designed. This chimeric protein, which contains B-cell epitopes and an adjuvant sequence, can potentially increase the likelihood of developing effective immune responses.
Materials and Methods: To increase the probability expression of the OTC protein, gene codons and various parameters effective in expression were optimized. The thermodynamic analysis of the mRNA structure was performed to verify stability. The third structure of the protein was predicted and the quality of the structures was evaluated. Linear and conformational epitopes were also determined.
Results: Protein with the sequence of OTC showed the highest antigenicity index. Codon Adaptaion Index of chimer increased to 0/89. The third predicted structure based on the RaptorX server showed good quality. The thermodynamic analysis of the mRNA structure showed that the predicted structure is stable. Conformational and linear epitopes were observed in all three domain of chimeric protein.
Conclusions: The results showed that the protein produced from this structure could act as an immunogen against the binding and toxin function of Vibrio cholera bacteria.
Background and Aims: Oncolytic viruses (OVs) are a new approach in treatment of cancer. Antitumor efficacy of OVs were limited due to insufficient and non-specific viral delivery to tumor sites. To overcome this issue, mesenchymal stem cells (MSCs) were used for their ability to specifically homing into tumors. The main aim of this study was to use MSCs as carriers and investigate the effect of oncolytic reovirus infection in MSCs, induction of apoptosis, nitric oxide (NO) secretion and their effects for selectively killing tumor cells, to use in future.
Materials and Methods: MSCs isolated from mice adipose tissue and confirmed. Then, the ability of the virus to infect MSCs and the effect of reovirus infection in induction of apoptosis and NO secretion in MSCs were evaluated.
Results: The results demonstrate that reovirus could replicate on MSCs. The finding indicated that the NO production significantly was higher at 72 h post infection with different MOI in comparison to the control cells. Also, reovirus induced high level of apoptosis in the MSCs at 48 h post infection compared with the control cells.
Conclusions: Based on observed results, reovirus increased the secretion of iNOS (inducible nitric oxide) in the infected MSCs at 48 h post infection; therefore, high amounts of NO and reovirus replication were found to trigger apoptosis at 48 h post infection. Therefore, by optimizing the replication time of virus in the MSCs, specific viral delivery to tumor sites are available and causes cancer cells’ death.
Background: the aim of this study was the isolation of phages able to lyse some strains of MDR-K. pneumoniae (named vB_Kp1 and vB_Kp2) and E. aerogenes (named vB_Ea1) from swages.
Materials and Methods: Different Klebsiella pneumoniae and Enterobacter aerogenesis strains isolated from clinical specimens (January to September 2018) in three Hospitals in Amol, (Mazandaran, Iran). Kirby Bauer’s disc diffusion method was used for determination of resistance profiles of these isolates using different antibiotics. The resistant strains to multi tested antibiotics (MDR) were selected to investigate the effect of isolated phages from wastewater and hospital sewage. Presence of phage investigated by plaque formation and after enriching and concentrating the isolated bacteriophages and staining the samples, a transmitting electron microscope (TEM) was used to observe the morphology of the bacteriophages. Phage identification tests including host range and One-step growth were performed.
Results: TEM analysis revealed that tree phages have an icosahedral capsid and long contractile tail. Therefore, they are a member of the Myoviridae family. Phages were able to lyse 14 (56%) of the 25 strains of multidrug-resistant bacteria isolated. The one-step growth curve showed large burst sizes and short latent times.
Conclusions: The formation of clear plaques shows the high lyse power of phages, so they have good potential for further analysis for clinical use as a therapeutic agent in the future.
Background and Aims: Pseudomonas aeruginosa is a potent pathogen for humans using multiple virulence factors. The purpose of this study was to investigate the effect of Saccharomyces cerevisiae lysates and supernatants on biofilm, alginate factors.
Materials and Methods: First, the supernatant extract and lysate were prepared from the native strain of Saccharomyces cerevisiae and turned into dry powder. Then, supernatant and lysate extracts were admixed with Pseudomonas aeruginosa strain PAO1 and strain M 8821, respectively, and biofilm in the strain PAO1 and alginate in strain 8821 M by Colorimetric method is measured by reading Optical Density(OD) also mention to the wave length. Supernatant with MIC concentration of 1/2 in both experiments and all concentrations of lysates in biofilm test and the highest concentration of lysates in alginate test were used.
Results: Supernatant of Saccharomyces cerevisiae at a concentration of 1 / 2MIC (0.512 mg / ml) with P
Background: The expression of most genes involved in pathogenesis in Pseudomonas aeruginosa is controlled and regulated by a gene system called quorum sensing (QS). The purpose of this study was to investigate the quorum quenching of garlic extract in preventing the expression of genes involved in QS system of P. aeruginosa.
Methods: In the present cross-sectional study, 12 P. aeruginosa strains were collected from burn wounds, cultured on special media and then confirmed by differential tests. The PCR test was performed to detect the lasI and lasR genes. The expression level of lasI gene was assessed in the presence of garlic extract and tobramycin antibiotic by real-time PCR, and the active ingredient of garlic extract was analyzed by HPLC.
Results: Examination of 12 strains cultured on special and differential media showed that all 12 strains were P. aeruginosa. The PCR results indicated that all strains had 100% lasI and lasR genes. The real-time PCR results also revealed that the garlic extract was able to reduce the expression level of lasI gene in P. aeruginosa. It was found that tobramycin has a greater ability to reduce the expression level of this gene compared with garlic extract.
Conclusion: This study showed that the garlic extract could reduce the expression of lasI gene in P. aeruginosa isolates, and that the active ingredients of this extract could be used to treat infections as an alternative to antibiotic therapy.
Background: Disinfectants have important clinical applications. Antibiotic resistance of some hospital pathogens such as Pseudomonas aeruginosa has led to the use of disinfectants. In the present study, the effects of four commercial disinfectants; Hydrocare, Benzalkonium Chloride, Cetrimide-C, and Vico sience on Pseudomonas aeruginosa isolates were investigated.
Materials & Methods: The dilutions of four tested disinfectants recommended by the manufacturer were prepared and their effects on twelve Pseudomonas aeruginosa isolates were evaluated at five, ten, fifteen minutes after the bacterial inoculation.
Results & Discussion: Hydrocare and Benzalkonium Chloride inhibited the growth of all strains while Cetrimide-C disinfectant did not inhibit the growth of bacterial strains at any time. The Vico sience completely inhibited the growth of bacterial strains at ten and fifteen minutes after the addition of disinfectant. Since the recommended dilutions by the manufacturer were prepared and evaluated in the present study, the inefficiency of some of the disinfectants indicated that the evaluation and dilution assay of the disinfectant is necessary prior to routine use in laboratories or health centers.
Background and Aims: A major problem in the treatment of Pseudomonas aeruginosa infections is the emergence of strains with multiple resistances (MDR). The aim of this study was to identify virulence genes lasB, toxA, algD, exos in P. aeruginosa isolated from human and animal using Multiplex-PCR method and determination of antibiotic resistance.
Materials and Methods: This cross-sectional study was performed on the 120 non-repetitive samples, including, 60 clinical samples of human and 60 animal samples collected from Tehran, Iran. Antibiotic susceptibility test was performed by disk diffusion test. The multiplex - PCR method was performed to identify various virulence genes.
Results & Conclusion: The highest resistance rate was related to amoxicillin and amikacin in the both types of samples. lasB and exoA genes were the most prevalent virulence determinants in the human and animals samples, respectively. The results of antibiotic susceptibility test showed that the resistance in human strains was far higher than animal and this could be the result of arbitrary administration of the drug. The lasB gene in human specimens and the exoA gene in animals play an important role in the development of the disease.
Background and Aims: Pseudomonas aeruginosa is an opportunistic pathogen that causes serious infections and high mortality among burn patients. The aim of this study is to evaluate the protective effects of a candidate divalent vaccine containing type A flagellin and pilin of P. aeruginosa in a burn wound mouse model.
Materials and Methods: Recombinant flagellin A and pilin proteins were generated by expressing fliC and pilA genes (cloned in pET-28a and pET-22b vectors, respectively) in E. coli BL-21. Groups of mice were immunized by injection of 10 µg of either flagellin A and pilin, or flagellin A, or pilin. Specific IgG titer was measured by ELISA. The functional activity of antibodies was evaluated by opsonophagocytosis assay. The protective effects of the vaccine were evaluated by measuring mortality and bacterial load in mice.
Results: Immunization with flagellin A and pilin mixture significantly increased the specific IgG antibody titer as well as opsonophagocytosis compared to monovalent antigens (P
Background and Aims: The type IV Pilin is an important colonization factor for opportunistic pathogens of Pseudomonas aeruginosa, which plays a role in the formation of biofilms and binding to the host cells. Each type of Pilin is coded with a particular auxiliary gene. This specific relationship can be used as a therapeutic target for detecting P. aeruginosa strains as well as its molecular classification. The purpose of this study was to evaluate the frequency of different types of auxiliary genes in cystic fibrosis, burns, and environmental samples.
Materials and Methods: Pseudomonas aeruginosa samples were collected from patients with cystic fibrosis, burns as well as environmental wastewaters during 2016-2017. Samples were cultured and identified using standard microbial and biochemical methods. DNA extraction was performed by boiling and PCR was performed through specific primers.
Results: Totally, 90 isolates of P. aeruginosa samples (35 environmental, 30 burns, and 25 cystic fibrosis) were examined. tfpO and tfpZ were positive in 71 and 2 isolates, respectively.
Conclusion: The results indicated that Pseudomonas aeruginosa Pilin types are very diverse. Regardless of the source of the samples, the most common tfp was tfpO. Taking into account the fact that tfpZ was found only in burns, it can be assumed that this particular type may appear in severe clinical conditions. Ultimately, larger statistical population and use of more comprehensive typing methods is suggested for better results.
Background and Aims: Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli are the most important bacteria responsible for hospital infections with multiple antibiotic resistance. Problems in the treatment of infections caused by resistant isolates have been the factor for the investigation of alternative drugs, including medicinal plants.
Materials and Methods: In this experimental study, antimicrobial activity of aqueous and alcoholic extract of Garlic and Aloe vera on 63 strains of P. aeruginosa, S. aureus and E. coli isolated from clinical specimens were investigated. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) was carried out by tube dilution method.
Results and Conclusion: In the MIC test, E. coli isolates showed the most sensitivity to the aqueous (with mean MIC, MBC 236.8 and 473.6 mg/ml, respectively) and alcoholic extract of the Garlic (with mean MIC, MBC 329.6 and 659.2 mg/ml, respectively) (P
Background and Objective: Pseudomonas aeruginosa is an opportunistic pathogen, and alginate is its most important factor in pathogenicity. The objective of the study is the immunogenicity evaluation of P. Pseudomonas aeruginosa alginate conjugated to exotoxin A as a vaccine candidate in mice.
Materials and Methods: The mucoid strain of Pseudomonas aeruginosa 6494 was used to prepare alginate, and the separation of exotoxin A was done with the standard strain of PAO1. Alginate was extracted by means of sedimentation with cold ethanol, dialysis, enzymatic digestion and chromatography. To improve immunogenicity, purified antigen was coupled to exotoxin A with ADH as a spacer and EDAC as a linker. Based on confirmation tests, the resulting conjugate was devoid of specific toxicity and pyrogenic effect. Four groups of BALB/c female mice (each group was included 15 mice) were selected in the next step. The first group with the ALG, the second group with the D-ALG-ETA, and the third one with the ETA were vaccinated. The fourth group (control group) was vaccinated with normal saline. Vaccination was performed in three injectable doses with two-week intervals. Subsequently, serum samples were collected, and antibody responses were measured by the ELISA method for total IgG, IgG1, IgG2a, IgG2b, IgG3.
Results: After the second and third doses with ALG-ETA showed a significant increase in antibody titer against ALG-ETA in comparison with pure ALG. The titers of IgG2a, IgG2b, IgG, IgG1, IgG3 antibodies that produced against alginate increased in the third injection compared to the first conjugate injection, which was 2.9, 3, 5.2, 10, and 9.2, respectively.
Conclusion: These results show that ALG from Pseudomonas aeruginosa increases anti-alginate antibodies in conjugate form with exotoxin A and can be considered an appropriate, effective adjuvant.
Background: Pseudomonas aeruginosa infections are resistant to antimicrobial agents and produce toxic virulence factors such as exotoxin A. Studies have shown that some nanoparticle compounds and antibiotics have a synergistic effect. Therefore, the aim of this study was to investigate the synergistic effect of silver nanoparticles and erythromycin on antibiotic-resistant P. aeruginosa.
Materials & Methods: In this descriptive cross-sectional study, 40 cultured samples of burn wound secretions were taken from Imam Musa Kazem (PBUH) Burns Hospital in Isfahan, Iran. Diagnostic and differential tests were performed. Antibiogram was performed to obtain the bacterial resistance pattern and the exotoxin A gene was detected by PCR. The bacterial minimum inhibitory concentration (MIC) was then applied to the silver nanoparticles (shape and mean size) and erythromycin separately and a common mixture of both in 10 dilutions to investigate the synergistic effect.
Results & Conclusion: A number of 26 bacteria were strains of P. aeruginosa. Of samples, 25 (96.15%) had exotoxin A gene. All samples were sensitive to all erythromycin concentrations. The mean MIC of nanoparticles against bacteria was reported to be 2 μg/mL. A solution of 40 μg/mL erythromycin and 2 μg/mL nanoparticles was also considered as MIC solution. Pseudomonas aeruginosa is sensitive to erythromycin to very low concentrations of silver particles. But no synergistic effect between silver nanoparticles and erythromycin was reported for this bacterium. Based on PCR results and antibiotic resistance pattern, a significant number of the samples contained the exotoxin A gene and the use of erythromycin alone was not appropriate for treatment.
Background and Aims: Pseudomonas aeruginosa is one of the most important pathogens of nosocomial infections, especially in the ICU (Intensive Care Unit), which has resistance to a wide range of antibiotics, especially Carbapenems. Among the most important resistance mechanisms of this bacteria against carbapenems are MexAB-OprM efflux pump. Therefore, the aim of this study was to evaluate the gene expression of MexAB-OprM efflux pump in clinical isolates of P. aeruginosa that isolated from ICU.
Materials and Methods: A total of 33 sampales were isolated from patient in ICU units from different Hamadan hospitals, since november 2018 to May 2019. Antibiotic susceptibility testing was performed using disk diffusion and Minimal Inhibitory Concentration (MIC) methods by Etest for imipenem. Expression levels of MexAB-OprM efflux pump genes were measured by Real-Time PCR.
Results: The results of statistical analysis showed that the highest resistance was to Ceftriaxone 21 (63.63%) and the lowest resistance was to piperacillin, 11 (33.33%). The results of the MIC of imipenem showed that among off 33 samples isolated from the ICU, 14 (42.42%) and 19 (57.57%) isolates were resistant and susceptible, respectively. Increased expression of of MexA, MexB and OprM genes compared with control strain were observed in 20% (4/20), 25% (5/20) and 20% (4/20) of isolates, respectively.
Conclusion: Increased expression of MexAB-OprM efflux pump is one of the most common mechanisms in the resistance of P. aeruginosa isolates against Carbapenem antibiotics in different units of hospitals especially intensive care unit. So identification of resistance mechanisms to Carbapenem antibiotics can be useful in controlling and treating such resistant isolates.
Background and Objective: Quorum sensing (QS) and virulence genes in Pseudomonas aeruginosa causing severe infections in humans. In the present study, the effect of chitosan (CS) and zinc oxide nanoparticles (ZnO-NPs) on the expression level of lasI, exoS and toxA genes during lag, exponential-and stationary growth phases of P. aeruginosa were studied.
Materials and Methods: CS and ZnO-NPs were synthesized by ionic gelation and ultrasonic methods, respectively. The clinical samples were collected from patients suffering from wound infections from 2018-2019, and preliminary identification of P. aeruginosa has done with the standard biochemical tests and 16S rDNA gene. The virulence genes (lasI, exoS and toxA) were detected by polymerase chain reaction (PCR). Finally, real-time reverse transcription-PCR (qRT-PCR) was performed to detect the expression level of QS and virulence-related genes in samples grown at a medium contain minimum inhibitory concentrations (MICs) of CS and ZnO-NPs.
Results: CS and ZnO-NPs were successfully prepared with average particle sizes of 20 and 40 nm. The prevalence rate of virulence-related genes among all clinical isolates originated from burn patients was as follows; toxA (100%), exoS (88%), and lasI (56%). The MIC value of CS was equal to 0.5 mg/mL, which is 8-fold lower than that for ZnO-NPs (4 mg/mL). qRT-PCR analysis revealed CS and ZnO-NPs decrease the expression of lasI, exoS, and toxA in clinical P. aeruginosa isolates during the exponential phase compared to other growth phases. toxA+/exoS+/lasI+ isolates exhibited similar patterns of gene expression changes in response to both NPs at all growth phases. Expression of toxA gene downregulated at exponential-and stationary growth phases of ATCC27853 treated with CS and ZnO-NPs.
Conclusion: The results obtained from this study may provide a better understanding of the expression changes of virulence-related genes throughout different growth phases of P. aeruginosa.