PLASMID PROFILING AND CURING ANALYSIS OF MULTI-DRUG RESISTANT NOSOCOMIAL BACTERIAL PATHOGENS FROM CLINICAL SAMPLES FROM UNIVERSITY OF BENIN TEACHING HOSPITAL, BENIN CITY, EDO STATE, NIGERIA

Abstract

One hundred and fifty nosocomial pathogens from 10 clinical sources from the University of Benin Teaching Hospital (UBTH), Benin City were isolated and identified. Staphylococcus aureus (30%) was the most predominant, while Klebsiella oxytoca, Citrobacter spp. and Streptococcus spp. were the least (0.7%). Their antibiotic resistance patterns were ascertained against 9 antibiotics. The isolates showed multiple resistance against 3 - 8 antibiotics. None was resistant to as few as 1 – 2 antibiotics. Resistance to cefuroxime (92.7%) was highest, and least to cefixime (34%). Curing experiment was carried out on all resistant isolates using 10% sodium dodecyl sulphate. Positive result was obtained in 149(99.3%) of the total isolates. Loss of antibiotic resistance marker was total in 7(4.7%) and variable in 142(94.6%). 1(0.7%) did not lose any resistance marker. These results were statistically significant (p< 0.05). Eighty five percent of strains cured of at least 50% of their resistant markers harboured plasmids. The plasmids ranging in molecular size from <0.56kb to >23.13kb were grouped into 12 plasmid profiles with the 23.13kb plasmid being the most common. The numbers of strains per plasmid profile group varied from 1-18.The acquisition of plasmids seem to have greatly contributed to the rapid spread of antibiotic resistance genes in the bacterial population.