Genotypic characterization of extended spectrum beta-lactamase in gram negative bacterial contaminants of some door handles in Olabisi Onabanjo University Teaching Hospital, Sagamu, Ogun state

Abstract

Background: Nosocomial infections due to cross-transmission by microorganisms from inanimate surfaces have become a recognized public health problem. Objectives: This research was carried out to detect bacterial contaminants of door handles and their production of extended spectrum beta-lactamase (ESBL) in Olabisi Onabanjo University Teaching Hospital. Methods: Seventy door handles from twenty-seven sections of Olabisi Onabanjo University Teaching Hospital were swabbed and inoculated on different culture media. The isolates were identified using standard microbiological procedures. Susceptibility of the isolates to eleven antibiotics was determined by Kirby- Bauer disc diffusion test. Phenotypic detection of ESBL was determined by modified double disc synergy test (MDDST) followed by PCR amplification of ESBL- encoding genes. Results: Forty-four (62.9%) out of 70 door swabs were positive for bacterial growth. S. aureus was the most common isolate (22.9%). Multidrug resistance was observed in 15(79.0%) and 20(69%) of Gram positive and Gram-negative isolates, respectively. Coagulase negative staphylococci, E. coli, Acinetobacter and Shigella species were totally resistant to ceftazidime (100%). PCR amplification of ESBL-genes revealed the presence of blaTEM blaCTX -M and blaSHV in 4(14.3%), 2(7.2%) and 1(3.6%) isolate, respectively. Conclusion: This study revealed that door handles of different sections in hospital environment were contaminated by multidrug resistant Gram-negative bacteria encoding ESBL genes. Keywords: Bacterial contamination; drug resistance; extended spectrum beta-lactamase.