TITLE:
Genetic Antimicrobial Resistant Staphylococcus Coagulase Negative Isolates from Nasals of Health Workers in Selected Hospitals in Makueni County
AUTHORS:
Caroline Nzomo, Samuel Kariuki, Susan Githii, Sepha Mabeya
KEYWORDS:
Coagulase-Negative Staphylococcus Species, Methicillin Resistance, mecA Gene, Health Care Workers
JOURNAL NAME:
Open Access Library Journal,
Vol.13 No.6,
June
11,
2026
ABSTRACT: Coagulase-negative staphylococci (CoNS) are common skin and mucous membrane flora but are increasingly recognized as opportunistic pathogens and reservoirs of antimicrobial resistance in healthcare settings. Nasal colonization among healthcare workers (HCWs) represents a potential source of transmission within healthcare facilities. This study assessed the prevalence, antimicrobial resistance patterns, and genotype characteristics of CoNS among HCWs at Makueni County Referral Hospital (MCRH) and Makindu Sub-County Hospital (MSCH). A total of 294 nasal swabs were collected from HCWs across different professional cadres. Isolates were identified by: inoculating on mannitol salt agar, followed by standard biochemical tests. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method, and polymerase chain reaction (PCR) was used to detect the mecA gene among phenotypically confirmed methicillin-resistant CoNS (MRCoNS) isolates. Overall, 87.8% (258/294) of HCWs were colonized with CoNS, with carriage rates of 88.7% at MCRH and 85.0% at MSCH, though the difference was not statistically significant (p = 0.378). CoNS isolates exhibited extensive antimicrobial resistance, including 100% resistance to penicillin, 96.6% kjto ampicillin, 71.3% to cefoxitin, 65% to ciprofloxacin, 60% to trimethoprim-sulfamethoxazole, 53.2% to clindamycin, and 47.8% to tetracycline. Erythromycin showed the lowest resistance at 30%. Among phenotypically confirmed MRCoNS isolates, the mecA gene was detected in 87.6% (177/202), while 12.4% (25/202) were mecA-negative. These findings demonstrate a high prevalence of multidrug-resistant and mecA-positive CoNS among HCWs and emphasize the importance of routine surveillance, detection of circulating resistance determinants, and strengthened infection prevention and control measures to reduce nosocomial transmission.Subject AreasAgricultural Science, Entomology