Epidemiological and antimicrobial susceptibility patterns of Staphylococcus aureus isolated from the nasal cavity of healthcare personnel at a public hospital in Northeastern Brazil: a cross-sectional survey

Abstract Nasal colonization by Staphylococcus aureus among healthcare professionals represents a potential risk for the spread of resistant strains in hospital settings. Thus, this cross-sectional study aimed to determine the prevalence of nasal colonization by S. aureus and to characterize the antimicrobial resistance profile of the isolated strains from professionals working in a public hospital in Caxias, Maranhão, Brazil. This study was carried out from December 2024 to February 2025. A total of 132 professionals working in a public hospital in the state of Maranhão were included. Among the participants, 36 (27.27%) were colonized by S. aureus , and 6 isolates (16.66%) were identified as methicillin-resistant S. aureus (MRSA). High resistance rates were observed to penicillin G and ampicillin (94.4%), as well as to the macrolides erythromycin (83.3%) and azithromycin (77.8%). Resistance to tetracycline was detected in 11.1% of the isolates, with 22.2% showing intermediate susceptibility. All isolates were susceptible to clindamycin, chloramphenicol, and rifampicin. Regarding risk factors, working in two healthcare locations compared to one remained significantly associated with nasal colonization after adjustment (OR = 3.15–3.50; p < 0.05), whereas longer professional experience was identified as a protective factor (OR ranging from 0.11 to 0.17; p < 0.05). These findings demonstrate the circulation of multidrug-resistant S. aureus strains among healthcare professionals and highlight the importance of active surveillance, rational antimicrobial use, and strengthened infection control strategies to reduce the spread of resistant pathogens in hospital environments.