Year: 2026
Type: preprint
Study design: Observational Study
Abstract: Aims The oral cavity is increasingly recognized as a reservoir of Staphylococcus species, yet knowledge gaps remain regarding species diversity, antimicrobial resistance (AMR), overlap with nasal carriage, and colonization persistence. Therefore, this study characterized oral and nasal Staphylococcus colonization in healthy young adults and explored the oral cavity as a potential niche for antimicrobial resistance (AMR) surveillance. Materials and methods Staphylococcus spp. from oral and nasal samples of 101 dentistry students were isolated and identified by MALDI-TOF MS. Antimicrobial susceptibility was assessed using EUCAST/CLSI guidelines. Longitudinal oral samples from a subgroup were analysed by Fourier transform infrared spectroscopy (FTIR-ATR) to explore strain persistence and turnover. Results Staphylococcus c olonization was highly prevalent (oral: 91%; nasal: 95%), with 86% concurrent oro-nasal colonization. Staphylococcus epidermidis predominated in both niches. Resistance to ≥ 1 antimicrobial was detected in 80% of coagulase-negative staphylococci (CoNS) and 73% of oral Staphylococcus aureus carriers. Multidrug-resistant phenotypes were found in 10% of CoNS carriers. Although multidrug-resistant and methicillin-resistant S. aureus was not detected, oral S. aureus frequently showed resistance to commonly prescribed dental antibiotics (amoxicillin, erythromycin, and clindamycin). Resistance frequencies were comparable between niches. Species-specific colonization dynamics suggested temporal turnover among Staphylococcus warneri and persistence-like clustering for S. aureus in some participants. Conclusions The oral cavity harbours diverse, frequently antimicrobial-resistant Staphylococcus populations at rates comparable to the nasal cavity. These findings support the oral cavity as a complementary ecological niche for Staphylococcus carriage, highlighting its relevance for future AMR surveillance strategies in dentistry and human health.
Source: Research Square
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: green
Funder: Universidade do Minho
OpenAlex ID: W7203733586