Staphylococcus aureus is an asymptomatic colonizer present in about 30% of the global population and is estimated to account for 17% of healthcare-associated infections (HAIs) worldwide. Due to its ability to form biofilms, this pathogen can survive for long periods on hospital surfaces, contributing to antimicrobial resistance. The objective of this study was to identify the prevalence of S. aureus in three public hospitals in Manaus, Amazonas.

Samples were collected from hospital surfaces using sterile swabs. They were inoculated in Brain Heart Infusion broth at 37°C for 24 hours, then isolated on selective Mannitol Salt Agar. Selected colonies underwent biochemical tests for species confirmation.

A total of 997 samples from hospital surfaces were collected, of which 544 (54.56%) showed S. aureus growth. Hospital A (HA) had the highest prevalence, with 38.90% positive samples, followed by Hospital B (HB) with 33.39%, and Hospital C (HC) with 27.71%. Among hospital sectors, the wards and intensive care units (ICUs) showed the highest colonization rates. In HA, 46.23% of ward and 37.26% of ICU samples were positive. In HB, positivity was 44.75% in wards and 43.09% in ICUs. In HC, the ward showed the highest prevalence (65.56%) compared to other hospitals, while the ICU had 17.22%. The most frequently contaminated surfaces were patient beds (HA: 12.26%; HB: 18.23%; HC: 33.77%), floors (HA: 14.15%; HB: 13.81%; HC: 8.61%), and oxygen regulators (HA: 10.38%; HB: 19.89%; HC: 26.49%).

This study revealed a high prevalence of S. aureus on hospital surfaces, which is concerning as these surfaces can act as reservoirs, facilitating cross-transmission in the hospital environment. Epidemiological studies are essential to better understand the behavior of this bacterium and to develop new protocols and strategies to reduce its spread.