Staphylococcus aureus Host Spectrum Correlates with Methicillin Resistance in a Multi-Species Ecosystem

Area of Science:

• Ecology
• Microbiology
• One Health

Background:

• Antibiotic resistance is a significant global health concern for humans and animals.
• Limited research exists on the role of bacterial host spectrum in antibiotic resistance spread within ecosystems.

Purpose of the Study:

• To investigate methicillin-resistant *Staphylococcus aureus* (MRSA) prevalence in various species at a Gabonese primatology center.
• To evaluate the influence of antibiotic pressure and host spectrum on MRSA acquisition and dissemination.

Main Methods:

• Prevalence assessment of MRSA in isolates from humans, non-human primates (NHPs), micromammals, and bats.
• Comparison of MRSA prevalence between antibiotic-exposed and unexposed species.
• Analysis of MRSA strain characteristics (generalist vs. specialist) and their association with host species.

Main Results:

• MRSA prevalence was higher in antibiotic-exposed species (humans, NHPs) than unexposed species (micromammals, bats).
• Higher MRSA prevalence was observed in NHPs in enclosures compared to those in captivity.
• Generalist MRSA strains, found in wild species, suggest interspecific transmission from exposed populations.
• Generalist strains not found in humans showed higher MRSA proportions than specialist strains.

Conclusions:

• Antibiotic pressure is a key factor in MRSA acquisition, amplified by irregular treatment.
• Generalist bacterial strains exhibit a greater propensity for acquiring antibiotic resistance.
• The host spectrum plays a crucial role in the dissemination of antibiotic resistance in ecosystems with significant human antibiotic use.