Phenotypic and Genotypic Determination of ESBL Producing E. coli and K. pneumoniae Strains Isolated From Dogs and Cats

The emergence and rapid spread of extended-spectrum beta-lactamase (ESBL)-producing bacteria of animal origin pose a threat to public health. Pathogens with zoonotic potentials, such as ESBL/AmpC-producing Escherichia coli and Klebsiella pneumoniae, can be transmitted from animals to humans through direct contact or contaminated environmental materials. This study was carried out to determine by phenotypic and genotypic methods ESBL/AmpC production of E. coli and K. pneumoniae strains isolated from healthy and diarrheic cats/dogs and determine multi-drug resistance via Kirby-Bauer Disc Diffusion Methods. Thirty-three K. pneumoniae and 167 E. coli were isolated and identified from stool samples. In the screening test, (38.5%) 77 isolates were evaluated as suspicious for ESBL production, and through confirmation tests performed with the double-disc synergy method, it was determined that 63 isolates produced ESBL phenotypically. The bla_SHV, bla_TEM, bla_CTX-M, and bla_OXA genes which were found to be 2, 33, 22, and 8, respectively responsible for ESBL production were determined by PCR. A total of 35 isolates were suspected of phenotypic AmpC production, and (94.2%) 33 were confirmed as AmpC positive by a three-dimensional test. The AmpC gene groups in E. coli strains have as follows: 14 strains CIT (AmpC origin-Citrobacter freundii), 13 strains FOX (cefoxitin), 11 strains ACC (Ambler class C), 3 strains DHA (Dhahran Hospital, Saudi Arabia), and 2 strains EBC (AmpC origin-Enterobacter cloacae). AmpC gene groups in K. pneumoniae strains have as follows: 4 strains CIT, 4 strains FOX, 3 strains ACC, and 2 strains EBC. Among E. coli strains canine origin was 69.7% (60/86), while 32 strains (39.5%) from feline origin showed Multi-drug resistance (MDR) profile. MDR among the K. pneumoniae strains from isolated dog origin was 28.5% (4/14) and six (31.5%) strains from feline origin were found to be MDR. Screening of phenotypic ESBL production of isolates was performed using antibiotic discs reported by CLSI. According to the results of our study, it was determined that ESBL/AmpC-producing bacteria were found at a higher rate in dogs. It was concluded that companion animals may pose a public health threat because they can contaminate the environment with their feces, and these bacteria may pose a zoonotic risk.