Distribution and Antibiotics Resistance Pattern of Community-Acquired Methicillin-Resistance Staphylococcus aureus in Southwestern Nigeria.

BACKGROUND

Methicillin-resistant Staphylococcus aureus is a global public health challenge and there is a continuous increase in community-acquired infections among people in different geographical location. We sought the distribution and antibiotics pattern of community-acquired methicillin-resistant Staphylococcus isolates among apparently healthy residents of Ibadan, Southwestern Nigeria.

METHODS

Seven hundred (700) healthy volunteers residing in Ibadan metropolis, Nigeria, were enrolled in this study. Isolates from the nasal swabs were aseptically collected and characterized using standard and established microbiological methods, which included growth and fermentation on mannitol salt agar, colonial morphology, Gram-staining reaction, Microbact™ 12S identification kit and confirmed with 16SrRNA. After identification of the isolates, antimicrobial susceptibility test was performed on Mueller-Hinton agar by modified Kirby-Bauer disc diffusion method and the presence of mecA and nuc genes were detected via polymerase chain reaction assay.

RESULTS

Prevalence of Staphylococcus aureus nasal carriage and Methicillin-resistant Staphylococcus in this study was 31.9% and 9.43% respectively. The residents of Ibadan North local government area (Fisher's Exact = 1.8962, P = .028) and Egbeda local government area (Fisher's Exact = 2.7222, P = .006) are likely to carry Methicillin-resistant Staphylococcus than any other local government area in Ibadan, Nigeria. The antimicrobial resistance patterns of the isolates revealed high resistance to Oxacillin (96.9%). Most of the isolates were sensitive to vancomycin (92.4%). Polymerase chain reaction analysis showed that mecA gene was present in all 66 (100%) Methicillin-resistant Staphylococcus aureus isolates. Male-gender (ϰ = 8.849, P = .003), Adults; 40-50 years old (ϰ = 9.842, P = .002), low educational background (ϰ = 36.817, P ˂ .001), recent hospital visitation (ϰ = 8.693, P = .003) are some of the factors that are observed in this study to be associated with Methicillin-resistant Staphylococcus infection.

CONCLUSION

Our findings revealed the relatively high frequency of nasal carriers of Methicillin-resistant Staphylococcus aureus among the apparently healthy residents of the studied area and the advent of multidrug resistance among these isolates. Our study also supports previous findings on male-gender and low educational background as risk factors of S. aureus carriage. The need for rational chemotherapy, routine detection and regular surveillance of Methicillin-resistant Staphylococcus to limit its spread and reduce treatment failures is important.