Search for Enterohaemorrhagic Escherichia coli O157:H7 and Salmonella enterica in the faeces and furs of apparently healthy kittens in Abeokuta, Nigeria

Abstract

Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 and Salmonella enterica are important zoonotic bacteria responsible for enteric infections in humans. The present study investigated the possible role of kittens in the zoonotic transmission of antimicrobial resistant EHEC O157 and Salmonella enterica to human using selective enrichment and isolation, biochemical characterization and serology. Out of all 90 (45 rectal and 45 fur swabs) samples examined, Escherichia coli was isolated from 38 (42.2%) comprising of 25 (55.5%) from faeces and 13 (28.9%) from furs. None of the E. coli isolates belonged to serotype O157:H7. Salmonella enterica was detected in three (3.3%) out of 90 samples including two (4.2%) from faecal samples and one (2.2%) from the fur samples. All identified bacterial isolates were tested for susceptibility to antimicrobials using the Kirby-Bauer disk diffusion method. Escherichia coli isolates were resistant to ampicillin (100%), tetracycline (100%), streptomycin (84.2%), cefotaxime (76.3%), nalidixic acid (73.2%), amoxicillin/clavulanic acid (71.1%), pefloxacin (52.6%), sulphonamide (52.6%), sulphamethoxazole/trimethoprim (50.0%), norfloxacin (42.1%), neomycin (36.8%), chloramphenicol (34.2%), ciprofloxacin (21.1%), gentamicin (21.1%) and kanamycin (18.4%). All three Salmonella enterica isolates were resistant to ampicillin, nalidixic acid, compound sulphonamide and streptomycin. Two Salmonella enterica isolates showed resistance to cefotaxime, ciprofloxacin, chloramphenicol, kanamycin, norfloxacin, pefloxacin and sulphamethoxazole/trimethoprim. Only one isolate showed resistance to amoxicillin/clavulanic acid and neomycin. The Salmonella enterica isolates were all susceptible to gentamicin. The present study showed that apparently healthy kittens harbour multidrug resistant E. coli and Salmonella enterica in their faeces and furs. These bacteria can be transmitted to humans through close contact with carrier cats.

Keywords: Antimicrobial resistance, EHEC O157, faeces, furs, kittens, Salmonella enterica.