Molecular characterization of multiple antibiotic-resistant Pseudomonas aeruginosa isolated from selected hospital fomites and hands of health care workers in Ondo, Nigeria

The study reported the molecular characterization, antibiotic susceptibility profile and the nature of resistance genes in the multiple antibiotic resistant Pseudomonas aeruginosa isolated from selected hospital fomites and hands of health care workers in Ondo, Nigeria. Various fomites and hands of health care workers were swabbed for the detection of Pseudomonas aeruginosa. Each sample was cultured separately on MacConkey and Centrimide agar plates and incubated for 18-24h at 37oC. Pure isolates were obtained using Analytical Profile Index (API) 20E kit. Kirby Bauer’s disc diffusion technique was used to decide the susceptibility of the pure isolates to known antibiotics. Resistant genes to 3 or more antibiotics were determined by Polymerase Chain Reaction (PCR) using appropriate primers. Two hundred Gram-negative bacterial isolates were recovered from 480 swab-stick samples analyzed out of which 54 were Pseudomonas aeruginosa. All the P. aeruginosa isolates showed total resistance to augmentin, cefixime and cefuroxime meanwhile 30 were resistant to nitrofuratoin, gentamycin 11, ceftazidime 7, ofloxacin 2 and ciprofloxacin 1. 31 (57.4%) were resistant to three or more classes of antibiotics. Out of the 12 representative isolates, 6 harboured blaCTX-M (585 bp) gene and were not susceptible to beta lactam antibiotics while 4 of the 7 Aminoglycoside (gentamycin) resistant isolates harboured aac-3-iv (286 bp) gene. In conclusion, different hospital fomites might be possible sources of nosocomial infections. Key words: P. aeruginosa, antibiotic-resistance, hospital workers, Ondo, Nigeria.