High Rates of Antimicrobial Resistance and Virulence Gene Distribution Among spp. Isolated from Pediatric Patients in Tehran, Iran.

Background: continues to be important causes of acute pediatric diarrhea worldwide. produces numerous virulence factors involved in colonization and invasion into epithelial cells which eventually result in the disease. The present study was conducted to evaluate the prevalence of virulence genes and to investigate antibiotic resistance profiles among isolates obtained from pediatric patients in Iran.

Methods: A total of 141 isolates were collected between March 2017 and September 2018 from stool of children under 14 who were suspected to have shigellosis. isolates were identified using standard microbiological and serological tests and antimicrobial susceptibility testing was carried out via Kirby-Bauer disk diffusion method. In addition, the presence of seven virulence determinants including , and were evaluated using PCR.

Results: (78.7%) was the most prevalent spp. among children with shigellosis followed by (19.9%) and (1.4%). Antimicrobial susceptibility testing revealed that most of the isolates were considered as multidrug-resistant (MDR) strains. Our findings also showed a high resistance rate against trimethoprim-sulfamethoxazole in isolates. The prevalence of , and were 100%, 95.7%, 95.7%, 94.3%, 93.6%, 92.9%, and 80.8%, respectively.

Conclusion: The current study revealed that was the predominant species isolated from children with shigellosis in Iran. Our results also indicated a high distribution of type III secretion system effector protein-encoding genes and high multidrug-resistance among shigella spp. in Iran. Therefore, it is suggested that antimicrobial susceptibility testing be performed prior to antibiotic prescription.