Background: Carbapenems are beta-lactam antibiotics that are considered as the last line of therapy against multidrug resistant extended spectrum beta-lactamase. The resistance to carbapenems predominantly through carbapenemase is one of the most important emerging health problems worldwide in the therapy of clinical infections. The objective of the present study is to determine the presence of carbapenemase encoding genes among Gram- negative bacterial spp. associated with clinical infections in dogs. Methods: 30 Escherichia coli, 11 Klebsiella pneumoniae and three Pseudomonas aeruginosa isolated from urine, swabs from lesional skin and anterior vagina of dogs presented with different clinical ailments formed the samples for the study. Polymerase chain reaction was carried out to detect the presence of carbapenemase encoding genes viz., KPC, NDM, OXA, VIM and IMP among the isolates.Result: Out of the 44 Gram- negative isolates tested, 28 (76.3%) were positive for at least one tested carbapenemase gene. The highest frequency of carbapenemase recorded was for NDM followed by OXA-181, KPC, OXA-48 and VIM. Our study identified a high prevalence of carbapenemases among companion animals like dogs which could act as potential source of transmission of these resistance bacteria or their genomes to humans.

Background: Antibiotic resistance is an emerging concern in the therapy of clinical infections worldwide. Previous studies conducted in our laboratory have confirmed an increase in the prevalence of extended spectrum beta-lactamase (ESBL) among the Gram-negative bacterial pathogens associated with dogs, which could act as a potential source for the transfer of these resistant pathogens or their genetic determinants to human. Since carbapenems are the last resort drugs against these resistant pathogens, the study was aimed to isolate and characterise carbapenem resistance among Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae) and Pseudomonas aeruginosa (P. aeruginosa) associated with common clinical infections in dogs.Methods: A total of 100 samples were collected from lesional skin, urine and anterior vagina of dogs presented to the Veterinary Hospitals of Kerala Veterinary and Animal Sciences University at Mannuthy and Thrissur. The samples were cultured onto Brain Heart Infusion Agar (BHIA), Eosin Methylene Blue (EMB) and Mac Conkey (MAC) for isolation of bacteria. Identification of the isolates was performed based on cultural, morphological and biochemical characteristics. The isolates were subjected to antimicrobial susceptibility test (ABST) against the 12 commonly used beta-lactam and non–beta-lactam group of antibiotics by disc diffusion method and further subjected to screening for ESBL double disc diffusion method. Carbapenem-resistant isolates were subjected to phenotypic confirmatory test for carbapenemase production employing Imipenem-EDTA and Ertapenem-boronic acid minimum inhibitory concentration (MIC) strip method.Result: Forty four Gram-negative bacterial isolates obtained were viz., E. coli (30), K. pneumonia (11) and P. aeruginosa (3) from the 100 samples. Apart from these, other isolates obtained were Staphylococcus spp. (53) and Bacillus spp. (2). All the Gram-negative isolates were subjected to ABST employing 12 common antibiotics belonging to beta-lactam and non-beta-lactam groups. Multidrug resistance (MDR) could be observed in 28 E. coli, 11 K. pneumoniae and three P. aeruginosa isolates. All the 42 MDR isolates showed positive results for ESBL production. A total of 14 isolates out of the 44 Gram-negative bacilli were found to be resistant to carbapenem either to imipenem, meropenem or ertapenem. Among the 14 Gram-negative isolates, nine turned out to be positive for metallo-beta-lactamase (MBL) and none for K. penumoniae carbapenemase (KPC) on phenotypic confirmatory test for detecting major carbapenemase enzymes. The present study documented that Gram- negative bacteria like E. coli, K. pneumoniae and P. aeruginosa isolated from dogs are showing an increase rate of resistance against carbapenems which are the last resort drugs against ESBL producers. Hence, there is an urgent need to curb the irrational and excessive use of antibiotics in veterinary sector.