Prevalência de Staphylococcus aureus e Staphylococcus aureus resistente à meticilina no meio ambiente bucal de pessoas idosas domiciliadas e acamadas, e fatores associados à essa colonização

Abstract

The elderly population is the fastest growing demographic in the world. As a consequence, there is an increase in the number of elderly people living at home or even bedridden, withvarying degrees of dependence. With aging, the immune system becomes less efficient, generating systemic impairments in the elderly, who become more vulnerable to possiblebacterial infections by multidrug-resistant pathogens. The objective of this studywastoevaluate the prevalence of Staphylococcus aureus and Methicillin-resistant Staphylococcusaureus (MRSA) colonizing the oral environment of elderly people living at home, whetherbedridden or not, as well as to evaluate factors associated with this colonization. Sampleswere collected from the oral environment of 263 elderly people from August to November2023, in the city of Natal/RN. The samples were collected with the help of swabs, whichwereplaced in saline solution and sent to the research laboratory. The samples were inoculatedinBHI (Brain Heart Infusion Broth) enrichment broth and after incubation were seededintheselective culture medium mannitol salt agar. Colonies suggestive of Staphylococcus aureuswere reisolated with subsequent identification through conventional laboratory tests andmassspectrometry (MALDI-TOF). The identification of the MRSA strain was performedbythedisk diffusion method, using the antimicrobial cefoxitin. The same technique was usedtoassess the susceptibility profile to other antimicrobials. Data related to sociodemographicfactors and access, care, and general and oral health conditions were collected throughtheapplication of a questionnaire. The prevalence of elderly individuals colonized by S. aureuswas 13.3% (n=35) and for MRSA it was 1.5% (n=4). The MRSA strains were resistant topenicillin, erythromycin, and clindamycin. After performing the multivariate analysis, thevariables that had a significant association with the presence of S. aureus were self-perceivedgeneral health (p=0.005) and difficulty in eating (p=0.006). Poor general health and difficultyin eating due to pain were the factors that contributed to colonization by S. aureus. Thepresence of S. aureus, especially the MRSA lineage, colonizing elderly people may represent a health risk to this population, especially due to their greater immunological vulnerability.