The Emerging of extended-spectrum β-lactamase producing Shigella sonnei in Tehran

Background: Emergence of extended-spectrum beta-lactamases (ESBLs) producing Shigella spp, resistance to third-generation of Cephalosporinsis a growing concern worldwide. The aim of this study was to determine emerging beta-lactam resistant Shigellasonnei, isolates during a short period in Milad hospital of Tehran. Methods: During two month from April to May 2018, a total of 32 Shigella species were isolated from patients admitted to Milad hospital of Tehran .Stool specimens of patients were inoculated to routine culture media such as blood agar, MaCkonkey and XLD agar. Suspected colonies were identified by routine laboratory tests and all confirmed isolates were serogrouped by commercially available antisera. Susceptibility testing was performed by disk diffusion method as recommended by CLSI guideline. Our primary results revealed a high rate of resistance to routinely used antibiotics including the third generation of cephelaspourins. All isolated were sent to Iranian Reference Health Laboratory for further studies such as MIC detection and molecular typing by PFGE method. Results: During two month April and May 2018 in total 32 strains of Shigella serotypes including 31 Sh.sonnei and one Sh .flexneri serotype were isolated from out patients admitted to Milad hospital of Tehran. The majority of patents were children under under14 years old. All isolates had the same antimicrobial resistance pattern and were resistant to Ampicillin, Ceftriaxone, Cefotaxime and Trimethoprim/Sulfamethoxazole. All isolates of Shigellasonnei were susceptible to Ciprofloxacin by E-test method and intermediate by Disk dissuasion methods. All Shigella isolates were ESLBs positive by double disk confirmatory method. Conclusion: Our study revealed an emerging resistance among Shigella isolates especially producing ESBLs .Emerging of MDR resistant strains among Shigella isolates is an important treatment issue worldwide.

کلیدواژه ها:

Shigella ، Extended-spectrum β-lactamase (ESBLs)