Phenotypic and genotypic evaluation of ESBL- and AmpC-producing Escherichia coli isolated from chicken distributed in Birjand, East of Iran

The aims of the present study were to detect Escherichia coli in chicken distributed in Birjand, to investigate the prevalence of ESBL and AmpC beta-lactamases producers among them, and to identify their antibiotic resistance patterns. The study was conducted on 150 chicken samples, and the antimicrobial susceptibility patterns were determined by the Kirby–Bauer disk diffusion method. Phenotypic identification of ESBL and AmpC was performed by the combined disk test (CDT). The specific genes of ESBL and AmpC beta-lactamases were detected using two multiplex PCR (m-PCR) assays. According to our results, 116 out of 150 chicken samples were contaminated with E. coli. Moreover, the highest resistance of E. coli isolates was observed to trimethoprim/sulfamethoxazole (46%), ampicillin (40%), and amoxicillin (29.33%). In the molecular confirmation step, among 17 (11.33%) beta-lactamase producers, five samples contained the blaCTX-M14 gene (3.33%), two samples contained blaDHA (1.33%) and blaCTX-M3 gene (1.33%), and just one sample carried blaCMY-2 gene (0.66%). The blaSHV and blaTEM genes were not detected in any strains isolated from the chicken samples. This study showed the contamination of chicken with antibiotic-resistant E. coli. Therefore, it is recommended that veterinarians be more precautious in prescribing antibiotics.

Antimicrobial Susceptibility Profile of Enterococcus Species Isolated from Companion Birds and Poultry in the Northeast of Iran

Enterococci are Gram-positive facultative anaerobic bacteria commonly found in the gastrointestinal tract of the mammals and birds. These cocci are isolated from urinary tract infections, bacteremia, endocarditis, and burn wounds in humans. The evolution of antibiotic-resistant enterococci raised a problem due to the possibility of the transmission of these organisms between poultry and human. Regarding this, the present study was conducted to evaluate the prevalence of Enterococcus species among companion birds and poultry in the Northeastern of Iran and determine the antibiotic susceptibility profile of enterococci. To this end, oral and cloacal swabs were collected from 150 caged birds. Antibiotic susceptibility profile was determined using the standard disk diffusion method. The results revealed that out of 150 samples, 56 (37.33%) cases contained enterococci. Most of the specimens (25.33%) were Enterococcus faecalis isolated from 6.66% of the samples. Additionally, 2.66% and 1.33% of the samples were contaminated with Enterococcus mundtii and Enterococcus gallinarum, respectively. Furthermore, Enterococcus malodoratus and Enterococcus raffinosus were isolated from 0.66% of the samples. The results revealed that all of the isolates of E. faecalis and E. faecium were resistant to more than five antimicrobial agents. Most of E. faecalis and E. faecium isolates showed resistance to Cefazolin, Tiamulin, Flumequine, and Cephalexin. Accordingly, the majority of the isolates had multidrug resistance to the tested antibiotics. In conclusion, the presence of multidrug-resistant enterococci in the birds living close to humans requires thorough observations due to the transmission of these organisms to humans.