Evaluation of Class 1 and 2 Integrons and Antibiotic Resistance Pattern in Salmonella enterica Isolated from Diarrheal Food-Borne Outbreaks in Iran

Abstract

Background: Salmonella spp. are major causes of food-borne disease and have been identified among many diarrheal outbreaks. The major aim of the current investigation was to evaluate the class 1 and 2 integrons and antibiotic resistance pattern in Salmonella enterica isolated from diarrheal food-borne outbreaks in Iran. 

Methods: This study was carried out on 115 diarrheal feces samples obtained from
food-borne outbreak in 2016 in Iran. Antimicrobial resistance patterns of 27 isolated
S. enterica seovars and presence of class 1 and class 2 integrons in the serovars were
investigated using conventional and molecular methods. Results were statistically
analyzed using SPSS software v. 21 and Chi-Square test.

Results: Overall, 27 S. enterica were characterized as 14 S. Paratyphi C, 7 S. Enteritidis, 5 S. Paratyphi D, and 1 S. Paratyphi A serovars. Results of molecular assay showed that class 1 integron presented in all and class 2 integron in three strains. All isolates with class 2 integron genes were resistant to almost all the antimicrobials.

Conclusion: Most studied Salmonella strains from diarrheal food-borne outbreak of Iran in 2016 were multiple resistant to the highlighted antimicrobials. Knowledge about risk factor involving the salmonellosis and their control measures could help the national
authorities to prevent the outbreaks. Further comprehensive studies with larger sample sizes are necessary to acquire more data about risk factors of multiple resistant
Salmonella outbreaks in the country.