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Background and Objective: The most common enterohemorrhagic Escherichia coli strain is the O157: H7 serotype, which is one of the most important intestinal pathogens and can cause complications such as hemorrhagic colitis, hemolytic uremic syndrome and acute renal failure. The aim of this study was to evaluate the enterohemorrhagic Escherichia coli causing molecular outbreaks of foodborne illness in Iran.
Methods: In this descriptive cross-sectional study, 189 fecal swab specimens were examined during April to September 2018. All suspected isolates were tested for biochemical tests. The isolates were confirmed by molecular PCR and evaluated by antimicrobial susceptibility tests.
Results: From 189 stool swab samples studied, 98 Escherichia coli isolates were detected based on phenotypic tests. Most of the outbreaks occurred in summer and the prevalence of enterohemorrhagic Escherichia coli was 24.5%, which 4% of them were non-O157H7. Most patients were between 1 and 12 years of age and the highest antibiotic resistance to cotrimoxazole and chloramphenicol was observed at 80% and 79%, respectively.
Conclusion: This study showed an increase in enterohemorrhagic Escherichia coli with 24.5% and an increase in antibiotic resistance to the antibiotics of chloramphenicol, cotrimoxazole and carbapenems. Increased resistance to imipenem and meropenem antibiotics makes it difficult to treat beta-lactamase-resistant strains.

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Background and Objective: Campylobacter is one of the most important pathogens causing bacterial gastroenteritis, which is usually transmitted through the food of animal origin. This study was done to evaluate the status of Campylobacter in diarrheal food outbreaks compared to other microbial agents.
Methods: This descriptive study was performed on 305 diarrheal swab samples from 102 food outbreaks during six months from spring to the end of summer 2018. Presence of Campylobacter species were assessed according to the protocol of the General Directorate of Laboratory Affairs.
Results: Out of 305 samples, 8 (2.6%) were identified as Campylobacter species, 3 (37.5%) Campylobacter and 5 (62.5%) Campylobacter coli. The epidemiology of the outbreaks showed that female (54.5%), average age of 16-30 years (28.2%), consumption of salads and vegetables (16.1%) and living in the cities (59.7%) were the most cases.
Conclusion: This study showed that in addition to classic pathogens such as Salmonella, Shigella, Escherichia coli, attention also should be paid to Campylobacter bacteria. In addition, recognizing epidemiological factors can play an important role in preventing and controlling food outbreaks.

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Background and Objective: Yersinia is water and foodborne organism that cause human gastroenteritis. This study was done to evaluate the frequency of Yersinia species isolated from children diarrheal samples and chicken meat in Tehran, Iran.
Methods: In this descriptive study 250 sample of diarrhea of children referred to the Children's Medical Center, Tehran, Iran and 250 samples of chicken were collected and examined for Yersinia infection during July 2016 to March 2017. Isolation method was performed based on initial enrichment in phosphate buffer for 3 weeks in refrigerator (cooling in c4 +) and then using KOH as secondary enrichment and culture on CIN agar medium. Biotyping method was used to determine pathogenic strains.
Results: In this study, 5(2%) isolates from pediatric diarrhea samples and 20 isolates (8%) from chicken meat samples were obtained from Yersiniaenterocolitica. Biotyping of human Yersiniaenterocolitica isolates identified 3 cases of biotype 1A, one case of biotype 1B, one case of biotype 2 and from chicken meat isolates, 16 isolates belonged to biotype 1A and 4 isolates belonged to biotype 1B.
Conclusion: Presence of common pathogenic 1B and non-pathogenic 1A biotypes in pediatric diarrhea samples and chicken meat can indicate the cause of diarrhea in children.