Detection of extended spectrum beta lactamases from pseudomonas aeruginosa isolates from otitis and pyoderma infections of canines

Pseudomonas aeruginosa is the most frequently isolated opportunistic Gram-negative bacilli from recurrent otitis and chronic suppurative skin infections of canines.Chronic infections are mainly due to the development of various resistance mechanisms, of which production of extended spectrum beta lactamases (ESBLs) is the most important.Therefore, the present study was carried out to detect the ESBLs production from Pseudomonas aeruginosa (P.aeruginosa) isolates of canines.A total of ninety-seven samples (n=97) were collected from otitis and pyoderma cases of canines.On microscopic, cultural and biochemical examination, 35 isolates were assumed to be P. aeruginosa.All 35 isolates were confirmed as P. aeruginosa by Polymerase Chain Reaction (PCR) using species-specific 16S rRNA primers that yielded a specific amplicon of 956 bp size.Phenotypic screening of ESBLs production was performed by employing Phenotypic Screening Test (PST), which suggested all isolates as "Suspect ESBLs producers".Twenty one isolates (21/35, 60%) were confirmed as ESBL producers based on the results of Double Disk Synergy Test (DDST).The genetic determinants of ESBLs were detected by using multiplex PCR (mPCR) which revealed the prevalence of bla TEM gene to be 20% (7/35), bla OXA to be 31.42%(11/35) and bla SHV to be 25.71% (9/35).