Study of class 1 integrons and plasmid profile among multiple drug resistant uropathogenic Escherichia coli

Pak J Pharm Sci. 2020 Nov;33(6):2643-2649.


The emergence of multidrug resistance in uropathogenic Escherichia coli (UPEC) is associated with the presence of drug resistant plasmids and integrons which facilitate horizontal gene transfer which impose serious challenges in patients with urinary tract infections (UTIs). The proposed research study is designed to determine emerging antibiotic resistance trends and the presence of plasmids and class 1 integron in UPEC. A total 74 strains of urinary pathogens were procured among them 50 UPEC isolates were selected and their antibiotic resistance pattern was performed by CLSI guidelines. Plasmid DNA of UPEC strains was extracted by kit method and profiling was done using gel electrophoresis. Class 1 integron genes intI1, sul1 and qacEΔ1 were detected by multiplex PCR in UPEC. Among gram negative urinary isolates, 50 (68%) isolates were E. coli, while the rest were Klebsiella, Pseudomonas, Enterobacter etc. All the tested UPEC were totally resistant to quinolones while sensitive to fosfomycin, imipenem and colistin antibiotics. Majority of multidrug resistant UPEC showed common resistant phenotype of fluoroquinolones, cephalosporins, sulfamethoxazole/trimethoprim and aminoglycosides. Out of the 50 UPEC isolates 46 (92%) were multi-drug resistant having one to three plasmids of more than 1kb and 41 (82%) possessed class 1 integron genes. Over all association between antibiotic resistance and presence of class 1 integron genes showed statistically significant results (p<0.05). Our results also depict a strong correlation between multidrug resistance and presence of class 1 integron in UPEC isolates (p<0.05). The presence of multiple plasmid bands in MDR E. coli strains and high prevalence of class 1 integrons indicate the role of plasmids and integrons in the horizontal transmission of antibiotic resistance genes in UPEC.