Antimicrobial Susceptibility Profiles of Staphylococcus aureus Strains from Ear, Nose and Wound Swabs of Patients Attending Health Care Facilities, Ebonyi Sate, Nigeria

Abstract

Aim: This study assessed age group related level of infection and antimicrobial susceptibility profiles of Staphylococcus aureus strains from a clinical specimen. Study Design: This is a prospective cross-sectional study conducted among in-patients and out- patients suspected of having a bacterial infection to determine the age group related level of infection and antimicrobial susceptibility profile of Staphylococcus aureus strains. Place and Duration of Study: The study was conducted between May, 2015 and June, 2016 at the Microbiology Laboratory of Akanu Ibiam Federal Polytechnic, Unwana, Ebonyi State, Nigeria. Methodology: A total of 723 clinical specimens including ear, nose and wound swabs were analysed for the presence of S. aureus. Standard microbiology laboratory tests were used to isolate and identify the strains. Antibiotic susceptibility testing of the strains was determined by the disc diffusion test (Kirby-Bauer method). Multidrug resistance was defined in this study as resistance to at least three different classes’ of antibiotics. Results: A total of 215 (29.74%)  S. aureus strains were obtained. The prevalence rate of S. aureus concerning types of specimen was 85 (51.52%) for wound swabs, 66 (33.33%) for nose swabs and 64 (17.78%) for ear swabs. There was no significant difference (P = 2.50) observed in the number of nose, ear and wound swabs that yielded S. aureus. Age group basis observation of S. aureus strains shows that the age group 21 – 30 years yielded the highest number of S. aureus strains representing 81 (37.67%).  In the tertiary hospital (MMH), almost all the strains showed high sensitivity to ofloxacin 101 (89.38%), followed by gentamycin 95 (84.07%). Antibiotic resistance was highest with cloxacillin 70 (61.95%) followed by cefuroxime 68 (60.18%). Also, in the teaching hospital (FETHA), a high level of sensitivity to ofloxacin 100 (98.04 %) and gentamycin 94 (92.16%) was recorded. Here, cloxacillin 61 (59.80%) followed by ceftazidime 57 (55.88%) showed the highest antibiotic resistance. A total of 76 (35.35%) of S. aureus strains were multidrug resistant (MDR).  Out of this total number of MDR S. aureus strains, 36 (42.35%), 24 (36.36%) and 16 (25.00%) were from wound, nose and ear swabs respectively. Constant antibiotic resistance monitoring is required in order guide physicians in choosing antibiotics against S. aureus.