Determinants of MRSA Colonization and Presence of the Panton-Valentine Leukocidin Gene (LUK-PVL) Among MRSA Isolates from People Living with HIV/AIDS at Irrua Specialist Teaching Hospital, Edo State, Nigeria

Background: Understanding which host characteristics predict Methicillin-resistant Staphyloccus aureus (MRSA) colonisation status and multi-site burden is essential for designing targeted infection-control strategies among people living with HIV/AIDS (PLWH). Concurrently, the Panton-Valentine Leukocidin gene (LUK-PVL), the molecular marker of hypervirulent communitY-associated MRSA (CA-MRSA), has not been characterized in any PLWH cohort from Edo State, Nigeria. This study investigates the participant-level and multi-site determinants of MRSA colonisation, and characterizes LUK-PVL prevalence and the clinical profile of PVL-positive isolates, in 176 PLWH at Irrua Specialist Teaching Hospital (ISTH).

Methods: 176 PLWH were screened for MRSA using three-site swabbing (nasal, axilla, groin; 528 specimens); 131 (74.43%) were MRSA-positive, yielding 230 isolates. Determinants of MRSA carriage status (N=176 participants) and multi-site colonization (≥2 positive sites, n=148 recoverable profiles) were assessed by chi-square, Mann-Whitney U, and binary logistic regression. LUK-PVL was detected by multiplex PCR (McClure protocol; amplicon 433 bp) in all 230 isolates.

Results: MRSA carriage was significantly associated with age group (χ²=9.900, p=0.042), occupation (χ²=7.173, p=0.047), WHO clinical stage (χ²=3.663, p=0.040), and CD4 count category (χ²=3.824, p=0.047). A clear immunosuppression gradient was observed: MRSA positivity was 86.5% at CD4 <200 cells/µL, declining to 69.6% at CD4 >500. Multi-site colonisation (41.2% of profiles) was independently predicted by hospitalisation within 6 months (aOR=4.30, p=0.011), within 12 months (aOR=4.59, p=0.010), and younger age (aOR=0.97/year, p=0.046); CD4 count was non-predictive (p=0.794). LUK-PVL was detected in 1 of 230 isolates (0.43%), from a recently hospitalised male with preserved CD4 (680 cells/µL), active skin infection, and a mecA+/SCCmecV+/SCCmecII− profile consistent with CA-MRSA.

Conclusion: MRSA colonisation in PLWH is determined by immune status at the level of initial carriage acquisition, and by healthcare contact at the level of multi-site dissemination. The near-absence of PVL confirms predominantly HA-MRSA lineage circulation. These findings support CD4-stratified MRSA screening and hospitalisation-linked decolonisation as the most targeted preventive strategies in this population.