Objective:The present study was carried out to appraise the antibiotic resistance and to detect some of the target resistant genes in Escherichia coli (E. coli) isolated from apparently healthy broilers.Materials and Methods:Cloacal swab samples (n = 60) were collected from apparently healthy broilers (n = 60) sold at two different live bird markets (LBMs) of Chattogram, Bangladesh. Isolation and identification of the Escherichia coli was done by the following standard bacteriological techniques followed by biochemical tests. The antibiotic susceptibility of E. coli isolates was determined by the disk diffusion method. The antibiotic resistant genes were detected by polymerase chain reaction (PCR) using specific primers.Results:The overall prevalence of E. coli in broilers was 61.67% (n = 37/60) (95% CI = 49–72.93). The antibiogram study showed that the isolates were 100% resistant to ampicillin and tetracycline followed by sulfomethoxazole-trimethoprim (94.59%, n = 35/37) and nalidixic acid (91.89%, n = 34/37). To the contrary, 56.76% (n = 21/37) isolates were sensitive to both ceftriaxone and gentamicin followed by colistin (48.65%, n = 18/37). All of E. coli isolates were multidrug resistant (MDR) and carried blaTEM, tetA, and Sul2 genes.Conclusion:The presence of MDR genes in E. coli isolates in broilers could pose a serious public health threat.

Sorbitol non-fermenting Shiga toxin producing Escherichia coli (SNF-STEC) is considered as a significant emerging pathogen. Though, cattle and buffaloes are the chief reservoir, species like goat, sheep, deer and other ruminants can also harbor this pathogen. Therefore, this pathogen can easily be transmitted to human and other animals through food chain and their environment. The present study, aimed to ascertain the antibiotic resistance profile of SNF-STEC isolates from buffaloes as well as to detect the resistance genes. A total of 33 sorbitol non-fermenting (SNF) E. coli isolates were tested against ten commonly used antibiotics both in human and veterinary medicine. Results revealed that 78.8% isolates were resistant to sulfamethoxazole-trimethoprim and nalidixic acid whereas 60.6% to tetracycline and 48.5% to doxycycline. The majority of the isolates were found sensitive to both gentamycin and ciprofloxacin (90%) followed by erythromycin (66.7%) and ceftriaxone (51.5%). Of 33 SNF E. coli, 12 were STEC harboring both stx1 and stx2 gene that dictated 66.7% isolates were found resistant to sulfamethoxazole-trimethoprim and nalidixic acid followed by ampicillin (58.3%) and tetracycline (58.3%). blaTEM was detected in 66.7% ampicillin resistant isolates and sul2 was exposed in 34.6% sulfamethoxazole-trimethoprim resistant isolates. sul1 gene was negative for the sulfamethoxazole-trimethoprim resistant isolates.