Negar Souod

Publications (7)10.92 Total impact

• Article: Uropathogenic Escherichia coli in Iran: Serogroup distributions, virulence factors and antimicrobial resistance properties.

  Hassan Momtaz, Azam Karimian, Mahboobeh Madani, Farhad Safarpoor Dehkordi, Reza Ranjbar, Meysam Sarshar, Negar Souod
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  ABSTRACT: BACKGROUND: Urinary tract infections (UTIs) are one of the most common bacterial infections with global expansion. These infections are predominantly caused by uropathogenic Escherichia coli (UPEC). METHODS: Totally, 123 strains of Escherichia coli isolated from UTIs patients, using bacterial culture method were subjected to polymerase chain reactions for detection of various O- serogroups, some urovirulence factors, antibiotic resistance genes and resistance to 13 different antibiotics. RESULTS: According to data, the distribution of O1, O2, O6, O7 and O16 serogroups were 2.43%, besides O22, O75 and O83 serogroups were 1.62%. Furthermore, the distribution of O4, O8, O15, O21 and O25 serogroups were 5.69%, 3.25%, 21.13%, 4.06% and 26.01%, respectively. Overall, the fim virulence gene had the highest (86.17%) while the usp virulence gene had the lowest distributions of virulence genes in UPEC strains isolated from UTIs patients. The vat and sen virulence genes were not detected in any UPEC strains. Totally, aadA1 (52.84%), and qnr (46.34%) were the most prevalent antibiotic resistance genes while the distribution of cat1 (15.44%), cmlA (15.44%) and dfrA1 (21.95%) were the least. Resistance to penicillin (100%) and tetracycline (73.98%) had the highest while resistance to nitrofurantoin (5.69%) and trimethoprim (16.26%) had the lowest frequencies. CONCLUSIONS: This study indicated that the UPEC strains which harbored the high numbers of virulence and antibiotic resistance genes had the high ability to cause diseases that are resistant to most antibiotics. In the current situation, it seems that the administration of penicillin and tetracycline for the treatment of UTIs is vain.
  Annals of Clinical Microbiology and Antimicrobials 04/2013; 12(1):8. · 2.64 Impact Factor
• Source

  Available from: Sadegh Ghorbani-Dalini

  Article: Epidemiological evaluation of Helicobacter pylori infection in patients with gastrointestinal disorders in Chahar Mahal and Bakhtiari province

  Mohammad Kargar, Negar Souod, Sadegh Ghorbani-Dalini, Abbas Doosti
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  ABSTRACT: Background & Objective: Helicobacter pylori is a bacterium responsible for one of the most prevalent infections found in humans worldwide. Considering the importance of this infection and its different prevalence in different regions of Iran, this study was conducted to determine the prevalence of Helicobacter pylori in Chahar Mahal and Bakhtiari as a high-risk province. Materials & Methods : This cross-sectional descriptive study was performed on 200 patients with dyspeptic symptoms referred to Hajar Hospital, Shahrekord. First, we applied the RUT and PCR assays to identify Helicobacter pylori-positive samples, and then performed SPSS software and statistical analyses to find the relationship between Helicobacter pylori infection and different kinds of diseases. Results: Out of all samples, 82% were infected with Helicobacter pylori. According to the data, there was a significant relationship between sex, level of education, and pain and Helicobacter pylori infection, while there was no relationship between the bacterium and age, family size, occupation, alcohol consumption, and smoking. Conclusion: Given the increased prevalence of Helicobacter pylori infection and its complications, health education and tight control of re-infection are recommended in patients.
  Journal of Fasa University of Medical Sciences. 02/2013; 2(4).
• Article: Study of Helicobacter pylori genotype status in saliva, dental plaques, stool and gastric biopsy samples.

  Hassan Momtaz, Negar Souod, Hossein Dabiri, Meysam Sarshar
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  ABSTRACT: To compare genotype of Helicobacter pylori (H. pylori) isolated from saliva, dental plaques, gastric biopsy, and stool of each patient in order to evaluate the mode of transmission of H. pylori infection. This cross-sectional descriptive study was performed on 300 antral gastric biopsy, saliva, dental plaque and stool samples which were obtained from patients undergoing upper gastrointestinal tract endoscopy referred to endoscopy centre of Hajar hospital of Shahrekord, Iran from March 2010 to February 2011. Initially, H. pylori strains were identified by rapid urease test (RUT) and polymerase chain reaction (PCR) were applied to determine the presence of H. pylori (ureC) and for genotyping of voculating cytotoxin gene A (vacA) and cytotoxin associated gene A (cagA) genes in each specimen. Finally the data were analyzed by using statistical formulas such as Chi-square and Fisher's exact tests to find any significant relationship between these genes and patient's diseases. P < 0.05 was considered statistically significant. Of 300 gastric biopsy samples, 77.66% were confirmed to be H. pylori positive by PCR assay while this bacterium were detected in 10.72% of saliva, 71.67% of stool samples. We were not able to find it in dental plaque specimens. The prevalence of H. pylori was 90.47% among patients with peptic ulcer disease (PUD), 80% among patients with gastric cancer, and 74.13% among patients with none ulcer dyspepsia (NUD) by PCR assay. The evaluation of vacA and cagA genes showed 6 differences between gastric biopsy and saliva specimens and 11 differences between gastric and stool specimens. 94.42% of H. pylori positive specimens were cagA positive and all samples had amplified band both for vacA s and m regions. There was significant relationship between vacA s1a/m1a and PUD diseases (P = 0.04), s2/m2 genotype and NUD diseases (P = 0.05). No statically significant relationship was found between cagA status with clinical outcomes and vacA genotypes (P = 0.65). The evaluation of vacA and cagA genes showed 6 differences between gastric biopsy and saliva specimens and 11 differences between gastric and stool specimens. Regard to high similarity in genotype of H. pylori isolates from saliva, stomach and stool, this study support the idea which fecal- oral is the main route of H. pylori transmission and oral cavity may serve as a reservoir for H. pylori, however, remarkable genotype diversity among stomach, saliva and stool samples showed that more than one H. pylori genotype may exist in a same patient.
  World Journal of Gastroenterology 05/2012; 18(17):2105-11. · 2.47 Impact Factor
• Article: Molecular Characterization of Shiga Toxin-Producing Escherichia coli Isolated from Ruminant and Donkey Raw Milk Samples and Traditional Dairy Products in Iran.

  Hassan Momtaz, Rahil Farzan, Ebrahim Rahimi, Farhad Safarpoor Dehkordi, Negar Souod
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  ABSTRACT: The aims of the current study were to detect the virulence factors and antibiotic resistance of Shiga toxin-producing E. coli, in animal milk and dairy products in Iran. After E. coli dentification with culture method, PCR assay were developed for detection of pathogenic genes, serotypes and antibiotic resistance genes of E. coli. Results showed that out of 719 samples, 102 (14.18%) were confirmed to be positive for E. coli and out of 102 positive samples, 17.64% were O26 and 13.72% were O157 and 1.96% were O91 and 1.96% were O145 serotypes. Totally, the prevalence of stx1 and papA genes were the highest while the prevalence of sfaS and fyuA were the lowest in the positive samples. PCR results showed that tetA, tetB were the highest (64.70%) and aac(3)-IV were the lowest (27.45%) antibiotic resistant genes in E. coli positive samples. Our study indicated that the isolated E. coli trains in these regions had a highest antibiotic resistance to tetracycline (58.82%) and the lowest to nitrofurantoin (3.92%). tetA gene and E. coli O157 serotype had highest and aac(3)-IV gene, and E. coli O145 serotype had a lowest frequency rates of antibiotics resistance genes, in the region.
  TheScientificWorldJOURNAL 01/2012; 2012:231342. · 1.66 Impact Factor
• Article: Real-time PCR for Helicobacter pylori quantification and detection of clarithromycin resistance in gastric tissue from patients with gastrointestinal disorders.

  Mohammad Kargar, Sadegh Ghorbani-Dalini, Abbas Doosti, Negar Souod
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  ABSTRACT: Helicobacter pylori gram-negative bacteria commonly infect the human gastrointestinal (GI) tract and are readily diagnosed by endoscopy. H. pylori infection causes a broad range of host symptoms from discomfort to significant GI disorders (GIDs). Severity of the clinical manifestations depends mainly upon bacterial load. In this cross-sectional study, we investigated the affects of 23S rRNA point mutations on H. pylori count in naturally infected human GI tissues. Two-hundred H. pylori patients with suspected GIDs were evaluated to determine bacteria concentration and presence of four known 23S rRNA point mutations, causing clarithromycin resistance. Gastric biopsy specimens were examined by rapid urease test and 16S rRNA-targeted PCR to identify H. pylori; then bacterial load was quantified by real-time PCR targeting wild type and known 23S rRNA mutations. Eighty-two percent of the samples were confirmed as H. pylori-positive, having 10(4)-10(12) colony-forming units (CFU)/ml. The 10(6) load was most strongly associated with peptidyltransferase point mutations of the 23S rRNA gene A2144G (p = 0.033), A2143G (p = 0.005), A2143C (p = 0.005), and A2142G (p = 0.015). Thus, our findings indicated that dominant 23S rRNA mutated H. pylori strains have the same growth rate as the wild type in a gastric environment.
  Research in Microbiology 12/2011; 163(2):109-13. · 2.76 Impact Factor
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  Available from: Sadegh Ghorbani-Dalini

  Article: Real-Time PCR Assay Using Allele-Specific TaqMan probe for Detection of Clarithromycin Resistance and Its Point Mutations in Helicobacter Pylori

  Mohammad Kargar, Sadegh Ghorbani-Dalini, Abbas Doosti, Negar Souod
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  ABSTRACT: Background: Helicobacter pylori is a fastidious microorganism and therefore standard phenotypic susceptibility tests can take at least 10-14 days. Molecular based diagnostic assays offer an alternative approach to obtain susceptibilities to antibiotics and detection of point mutations with greater accuracy. The aim of this study was the assessment of Clarithromycin resistance and its point mutations by using real-time PCR assay. Methods: This cross-sectional descriptive study was performed on 200 gastric biopsy specimens obtained from patients undergoing upper gastrointestinal endoscopy at Hajar hospital in Shahrekord. Initially Helicobacter pylori were identified by rapid urease test (RUT) and polymerase chain reaction (PCR). Then clarithromycin resistance and its point mutations were evaluated by using specific probes and real-time PCR technique. Findings: Of total samples, 164 (82%) were Helicobacter pylori positive. Overall, a clarithromycin susceptible strains were detected in 105 (64.02%) patients and resistance strains were detected in 59 (35.98%) which were identified as 4 (2.44%) A 2144G, 26 (15.85%) A2143G, 15 (9.15%) A2143C, and 20 (12.19%) A2142G point mutations. Genotype of 5 (8.47%) strains was not detected. Purely resistant strains were detected in 38 (23.17%), while heteroresistant were found in the remaining 16 cases (9.76%). Conclusion: Results showed that real-time PCR assay has high accuracy to simultaneously identify Helicobacter pylori and clarithromycin resistance types directly in gastric biopsy specimens in short time.
  Journal of Isfahan Medical School. 01/2011; 29:65-73.
• Article: Comparison of the virulence factors of Helicobacter pylori isolated in stomach and saliva in Iran.

  Hassan Momtaz, Negar Souod, Hossein Dabiri
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  ABSTRACT: Helicobacter pylori is a microaerophilic, spiral-shaped motile bacterium that is strongly associated with gastroduodenal diseases, but recently, dental plaque and saliva have been implicated as possible sources of H pylori infection. Two virulence factors that are expressed by the alleles of the cytotoxin genes, cagA and vacA, have been identified. The aim of this study was to compare cagA and vacA genotypes of H pylori between stomach and saliva in a same patient. This study was performed on antrum gastric biopsy specimens and saliva samples, which were obtained from 250 patients undergoing upper gastrointestinal tract endoscopy in Hagar Hospital of Shahrekord Township in Iran. Initially, H pylori strains were identified by rapid urease test; then, we applied polymerase chain reaction assay to analyze cagA and vacA genotypes of H pylori from both gastric and saliva specimens. One hundred eighty-nine (75.6%) and 36 (14.4%) samples were H pylori positive in gastric and saliva samples, respectively. Evaluation of virulence factors in the 36 patients whose saliva and gastric samples were both positive for H pylori showed a great deal of cytotoxin genotypic diversity between stomach and saliva in the same patient; in fact, 14 patients (38.8%) had different H pylori strains in their saliva and gastric samples. The data suggest that >1 H pylori strain may exist in stomach and saliva in the same patient.
  The American Journal of the Medical Sciences 11/2010; 340(5):345-9. · 1.39 Impact Factor