Antimicrobial Susceptibility and Molecular Detection of Integrons, Sulfonamides and Trimethoprim Resistance of Extra Drug-Resistant Escherichia coli Isolates

International Journal of Enteric Pathogens

article

Zahra Sabeti¹  Vahid Soheili²  Fatemeh Aflakian¹  Gholamreza Hashemitabar¹  Mahdi Askari Badouei¹ 

[1] Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad;Department of Pharmaceutical Control, School of Pharmacy, Mashhad University of Medical Sciences

关键词: Antimicrobial resistance;    Escherichia coli;    XDR;    Urinary tract infections;    sul genes;    dfr genes;    integrons;   

DOI  :  10.34172/ijep.2022.5510

学科分类：农业科学（综合）

来源: Alborz University of Medical Sciences

【 摘 要 】

Background: Escherichia coli , a gram-negative bacterium, is the causative agent for approximately 80% of urinary tract infections (UTIs). UTI treatment has resulted in the overuse of antibiotics in hospitals and communities, and subsequently the increase of antimicrobial resistance. The emergence of extensively drug resistance (XDR) strains has become a costly and dangerous challenge in the treatment of most bacterial infections and UTIs. Objective: This study aimed to determine the frequency of XDR isolates and investigate the distribution of common sulfonamide- (sul1, sul2, & sul3) and trimethoprim (dfrA1, dfrA12, & dfrA14) -related resistance genes among E. coli isolates from UTI patients. Furthermore, the isolates were sought for the presence of class 1 and class 2 integrons (Int1 & Int2) among XDR E. coli isolates. Materials and Methods: 120 uropathogenic- E. coli isolates recovered from UTI cases in Mashhad were assessed in 2017-2019. Overall, 39 out of 120 isolates were identified as XDR isolates as they were resistant to all classes of tested antibiotics, except for two or fewer comprising quinolones (first and second generation), cephalosporins (first and third generation), penicillins, tetracyclines, and sulfonamide-trimethoprim. Results: The antimicrobial susceptibility testing (AST) results determined a substantial resistance rate against cloxacillin (98.3%), oxacillin (98.3%), and cephalexin (94.17%). According to polymerase-chain reaction results, sul1 and dfrA14 genes with the frequency of 35 (89.74%) and 28 (71.79%) were identified as the most prevalent resistant genes among XDR isolates. In addition, int1 and int2 genes were detected among 23 (58.9%) and 8 (20.5%) XDR isolates, respectively. In conclusion, the substantial distribution of sul1 and dfrA14 genes was highlighted among XDR E. coli isolates recovered from UTI. Conclusion: Based on the present research findings, class I integrons play a major role in the dissemination of resistance gene cassettes, including sul and dfr in XDR isolates, and should be investigated in the future.

【 授权许可】

CC BY-NC