Occurrence of Methicilin-resistant Staphylococcus aureus in a Nigerian tertiary Hospital
A total of 3,692 clinical samples consisting 1,969 urine samples, 535 blood culture, 362 high vagina swabs, 207 endocervical swabs, 125 cerebrospinal fluid, 136 ear swabs, 200 eye swabs and 158 wound swabs were microbiologically investigated for Staphylococcus aureus and methicillin resistant Staphylococcus aureus at the Department of Medical Microbiology, University Teaching Hospital Ibadan. Two hundred and eight Staphylococcus aureus (5.6%) were isolated, twenty two, (10.6%) of which were methicilin resistant. Nine isolates 9/22(40.9%), were resistant to nine antibiotics having, R-type aug.amg.amx.pef.tet.cxc.e.nit.nal, two isolates 2/22 (9.1%) had octuple resistant pattern ; R-type aug.amg.amx.pef.cxc.e.nit.nal, four isolates 4/22 (18.2%) had septuple ; R-type aug.amg.amx.pef.cxc.e.nit resistant pattern, two isolates 2/22(9.1%) had quintuple ; R-type aug.amx.cxc.e.nit, one isolate 1/22 (4.5%) quadruple ; R-type aug.amx.cxc.nit, and another four isolates 4/22 (18.2%) had triple; R-type amx.cxc.nit. Seventeen, (77.3%) of the methicilin resistant Staphylococcus aureus, were resistant to 30mcg Ceftriaxone, while nineteen, (86.4%) were resistant to 30mcg Ceftazidime. All the twenty two methicilin resistant Staphylococcus aureus were resistant to Amoxycillin (25mcg), Cloxacillin (10mcg), Nitrofurantoin (300mcg), and Gentamycin (10mcg). The MIC of Ceftazidime for 3 isolates, 3/19(15.8%) was 120mcg/ml and the MIC of Ceftazidime for 16 isolates, 16/19 (84.2%) was 60mcg/ml, while the MIC of Ceftriaxone for 1 isolate, 1/17 (5.9%), 6 isolates, 6/17 (35.3%) , 10 isolates, 10/17 (58.8%) were >150mcg/ml, 150mcg/ml, 75mcg/ml respectively and the MIC of Ceftriaxone for the remaining 6 isolates, 6/17(35.3%) was 37.5mcg/ml . Taking into consideration the danger associated with methicillin resistant Staphylococcus aureus, the findings from this study underscores the need for public enlightenment of both the hospital workers and the general public on the risk associated with this group of globally important pathogens and the necessary precautions for its control both in the hospitals and the communities in Nigeria.
Key Words: Methicilin resistant Staphylococcus aureus, Ibadan, Nigeria