Distribution of Macrolide, Lincosamide, and Streptogramin B and Detection of erm Genes in Staphylococcus aureus from Wounds in Uyo, Nigeria

The increasing resistance to macrolide, lincosamide, and streptogramin B (MLSB) among methicillin-resistant Staphylococcus aureus (MRSA) is a challenge. The study determined the constitutive and inducible MLSB resistance and erm genes in S. aureus from wounds using the erythromycin-clindamycin D-zone test and a multiplex polymerase chain reaction assay, respectively. Of the 260 patients recruited in the study, S. aureus was isolated from the wounds of 102 patients, giving a prevalence rate of 39.2%. Of the 102 S. aureus isolates, 32.4% were methicillin-sensitive S. aureus (MSSA), and 67.6% were MRSA. The prevalence of S. aureus in wounds was higher in females (39.8%) than in males (38.4%). The highest prevalence of S. aureus was found in divorce patients (59.1%) and those residing in urban areas (39.7%). There was no statistical difference between the occurrence of MRSA and MSSA in wounds based on the sex (p = 0.97), age (p = 0.08), and marital status (p = 0.41) of the patients. All (100%) MRSA were resistant to Cefoxitin, and chloramphenicol, while ˂ 50% of MRSA were resistant to Tetracycline, Ciprofloxacin, and Gentamycin. Of the 69 MRSA isolates from the wounds, 21.7% and 26.1% were iMLSB and cMLSB phenotypes, respectively. Nine (9) MSSA were iMLSB phenotypes, and eight MSSA were cMLSB phenotypes. Among the 12 representative isolates, three (3) MRSA and one (1) MSSA isolate possessed the ermC gene. This study has revealed that screening tests for iMLSB-resistant S. aureus strains are critical for the therapeutic management of wound infections caused by S. aureus.