Prevalence Of Multi-Drug Resistant Staphylococcus Aureus In Clinical Specimens Obtained From Patients Attending The University Of Benin Teaching Hospital, Benin City, Nigeria.

Abstract

Methicillin resistant Staphylococcus aureus (MRSA) is a source of hospital required infection (HAI) world-wide and an important human pathogen that is found in most communities in Nigeria. The study was carried out to determine the prevalence and resistance pattern of methicillin-resistant strains of Staphylococcus aureus in specimens of pus, wound, aspirates and swabs obtained from patients attending the University of Benin Hospital, Benin City. A total of 3612 samples collected by clinical staff and sent for routine examination were bacteriologically processed using standard methods. Sensitivity tests were carried out by the disc diffusion method and minimum inhibitory concentration (MIC) was determined with graded concentrations of oxacillin in Mueller-Hinton agar. A total of 3,533 (97.2%) isolates were obtained of which 1315 (37.2%) were Staphylococcus aureus. Methicillin-resistant stains of the Staphylococcus aureus isolates were 1039 (79%). MRSA was isolated at a significantly higher (p<0.05) rate from pus and wounds of women than men. All the MRSA were resistant to ampicillin (100%), 99.8% to streptomycin and 99.9% to tetracycline. Resistance to amoxycillin-clavulanate (28.6%) was significantly lower (p<0.001) compared to other agents except for vancomycin resistance (0.007%). Therefore, the use of antimicrobial agents other than vancomycin can be successful after sensitivity tests have been carefully carried out. The need to improve on the public health awareness of the use of antimicrobial agents is further encouraged as this would reduce the incidence and prevalence of resistance among clinical isolates especially MRSA.

Key words: Staphylococcus aureus, prevalence, multi-drug resistance, antimicrobial agents .