Iranian Journal of Medical Microbiology

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: 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: 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 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 Aim: Increasing of resistant bacteria is a major concern globally. The emergence of XDR gram-negative bacteria is a more serious problem due to treatment limitations. This study aimed to evaluate the frequency of extensively drug-resistant (XDR) gram-negative bacterial isolates in different clinical samples from Payvand Clinical and Specialty Laboratory, Tehran, Iran, for 6 months by VITEK 2 system. Materials and Methods: During March 2020-September 2020, different clinical samples were collected from patients referred to Payvand Clinical and Specialty Laboratory. Bacterial identification and antimicrobial susceptibility test (AST) were performed applying an automated VITEK 2 system. The frequency of identified bacteria, their resistance to common antibiotics and also XDR bacteria were calculated and reported, respectively. Results: Overall, 4125 urine specimens, 34 sputum samples, and 1 tracheal aspirate tube were submitted to Payvand Laboratory during 6 months. Of them, 486 urine, 32 sputum, and a tracheal aspirate tube samples were culture positive. Gram-negative isolated bacteria were included in this study. Based on AST, 63.3% of the isolated Klebsiella pneumoniae, 100% of Pseudomonas aeruginosa, and all Acinetobacter baumannii isolates were susceptible to amikacin and colistin. Totally, 31 XDR gram-negative bacteria, including: K. pneumonia (ssp. pneumonia (n=20), and ozaenae (n=2), Escherichia coli (n=3), P. aeruginosa (n=5), and A. baumannii (n=1) were identified from 18 urine samples, 12 sputum specimens, and a tracheal aspirate tube. Conclusion: The rate of XDR bacteria was high in the investigated laboratory in this study. Therefore, accurate screening and antimicrobial stewardship is recommended in different medical centers of Iran. © 2022 This is an original open-access article distributed under the terms of the Creative Commons Attribution-noncommercial 4.0 International License. All Rights Reserved.

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 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 Aim: Carbapenem-resistant Acinetobacter baumannii (CRAb) has ability to develop and acquire resistance makes it one of the most critical nosocomial pathogens globally. Whole genome sequemcing (WGS) technology was employed to map genes associated with antimicrobial resistance (AMR),virulene factors and to identify multilocus sequence types (MLST). In order to understand the resistance mechanism for A. baumannii species, this study set out to establish the genetic makeup of the species. Materials and Methods: Whole-genome sequencing (WGS) of A.b4, A.b49 and A.b75 was performed using Illumina MiSeq and the genomes were assembled with SPAdes. ARG-ANNOT, CARD-RGI, VFDB, PHAST, PlasmidFinder were used to analyse all genomes. Results: Genome analysis revealed that Ab4 belongs to ST944, represented singletons that could not be attributed to any, A.b49 belongs to ST1104, represented unique ST.While A.b75 belongs to ST195 which represented known international clones of high risk .Molecular characterisation showed the presence 23 antibiotic resistance genes in all straines of A. baumannii. 12 of them are shared by all 3 strains and 11 are common between A. baumannii 4(ST/944), 49 (ST/1104) and 75(ST/195). The common drug-resistance genes shared by all 3 strains include bla OXA-72 (resistance to carbapenems), ade genes, RND (adeFJK, adeLN & adeR), and SMR (abeS) encoding for efflux pumps. Conclusion: We present WGS analysis of three A. baumannii strains belonging to three different STs. The presence of strains harboring acquired AMR genes makes them more dangerous. Acquired resistance genes and chromosomal gene mutation are successful routes for disseminating AMR determinants among A. baumannii. Identification of chromosomal and plasmid-encoded AMR in the genome of A. baumannii may help understand the mechanism behind the genetic mobilization and spread of AMR genes.

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.

ABSTRACT 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 1.0.0.0, 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 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.

ABSTRACT 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 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: 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: 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 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 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 and Aim: Carbapenem resistant-Pseudomonas aeruginosa (CRPA) is one of the most important causes of severe and persistent infections. The contributions of different resistance mechanisms to Carbapenems and biofilm formation among a collection of imipenem susceptible and non-susceptible P. aeruginosa isolates were investigated. Materials and Methods: In this cross-sectional study, a total of 117 P. aeruginosa isolates were collected. The disc diffusion method assessed the susceptibility of isolates to various antimicrobials. The Carbazole method was used for the detection of alginate producers. Multiplex-PCRs were performed for the detection of biofilm and resistance genes. The expression mRNA levels of efflux pumps were assessed by phenotypic and genotypic (Quantitative Real-time PCR) approaches. Results: The highest resistance rate was related to ceftazidime, chloramphenicol, ceftriaxone, tetracycline, and levofloxacin. MDR phenotype was observed in 8.4% of strains. The frequency of carbapenem resistance was also 24.7%. The Carbazole test was positive at 53.8%. In general, 62.4% of isolates were able to form a biofilm, 28.8% of which were resistant to carbapenem. The distribution of algD and algU genes were 41.8% and 26.5%, respectively. The frequency of MBL-encoded genes was as follows; blaIMP (62.1%), blaVIM (31.0%), and blaNDM (6.8%). The relative levels of MexX, MexC, MexB and MexA mRNA in CRPA strains with active efflux pump were 81.8%, 63.6%, 54.5%, and 36.4%, respectively. Conclusion: The existence of different resistant mechanisms in P. aeruginosa can cause cross antibiotic resistance, lead to the appearance of resistant strains, and make the treatment difficult. Biofilm production is directly related to antibiotic resistance. Efflux pumps are actively expressed in carbapenem-resistant strains. © 2022, This is an original open-access article distributed under the terms of the Creative Commons Attribution-noncommercial 4.0 International License which permits copy and redistribution of the material just in noncommercial usages with proper citation.

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