Phenotypic and genotypic characterization of extended-spectrum β-lactamase genes in Pseudomonas aeruginosa isolates from local dogs bred in Nsukka, Nigeria

One of the major public health concerns is the transmission of antibiotic-resistant bacteria including extended spectrum beta-lactamase (ESBL)-producing Pseudomonas aeruginosa (P. aeruginosa) from animals to humans. This study investigated the prevalence of blaSHV, blaCTX-M, blaOXA and blaTEM ESBL genes in P. aeruginosa isolates from Nigeria local dogs bred in Nsukka. Anal swab samples (n = 150) were bacteriologically analyzed on soybean casein digest broth and cetrimide agar for the enrichment and isolation of P. aeruginosa respectively. Antibiotic sensitivity test was done according to Clinical and Laboratory Standard Institute (CLSI) criteria. Extended-Spectrum B-Lactamases production was detected phenotypically using the double disc synergy test (DDST) method and genotypically multiplex PCR technique respectively. A total of 39 (26.0 %) of the 150 samples were P. aeruginosa which were multiply resistant to antibiotics tested. The P. aeruginosa isolates were found to be multiply resistant to antibiotics tested. Twenty-One (53.9%) of the isolates showed ESBL phenotype while 18 (46.2 %) of the isolates were confirmed ESBL positive by Polymerase Chain Reaction (PCR). The prevalence of blaSHV, blaCTX-M, blaOXA and blaTEM genes in P. aeruginosa tested were 4 (10.3%), 17 (43.6 %), 15 (38.5%), and 6 (15.4%), respectively. This study, therefore, reported multi-drug resistant ESBL-positive P. aeruginosa in these local dog breeds. The exposure of these animals to antibiotics accumulates antibiotic resistance determinants in their intestinal flora.