Staphylococcus aureus: PREVALENCE AND SUSCEPTIBILITY TO ANTIMICROBIALS IN PATIENTS ADMITTED TO AN INTENSIVE CARE UNIT WITH THE USE OF ARTIFICIAL RESPIRATORS

Staphylococcus is composed of at least 40 species, but only a few are of clinical and pathogenic importance to humans. Among these species, S. aureus is the pathogen that most affects humans, with a nosocomial characteristic, can be found in the oral mucosa, nasal, skin and digestive tract, but is capable of causing infection with a high resistance profile when the system immune system is weakened presenting defensive failures. The objective of this study was to analyze samples of endotracheal secretions after 24h of orotracheal intubation in patients admitted to an intensive care unit (ICU) of a hospital in the northwest of Paraná. Patients were selected regardless of gender, age, pathologic diagnosis at the time of admission, length of hospital stay, and prior antimicrobial use. These samples were sent to the laboratory after the collection procedure performed by the physiotherapists of the hospital, and the standard procedures of microbiological growth by inoculation and scoring were performed and submitted to automated analysis by the Phoenix ®TM system of panel 105 of the corresponding DB to Gram-positive cocci, thus reporting the frequencies of each microorganism found and their respective susceptibility profiles to 27 antimicrobials. A total of 367 patients presented positive cultures for the microorganism, being Pseudomonas aeruginosa isolated from 77 (21%) samples, followed by S. aureus in 70 (19%) samples, and Acinetobacter baumannii isolated from 59 (16%) samples. Of the 70 samples identified as S. aureus, 66% presented resistance to some antimicrobial like; ampicillin, cefoxitin, streptomycin-S, gentamicin-S and penicillin G. In relation to the antimicrobial cefoxitin, which replaced old methicillin, 70 (100%) samples of S. aureus presented resistance, thus conferring the profile of methicillin-resistant Staphylococcus aureus (MRSA), 100% resistance to beta-lactams and aminoglycosides was observed for antimicrobial classes, followed by 98% to nitrufurans and 95% resistance to quinolones. The results show that P. aeruginosa and S. aureus infections in ICU are highly prevalent and S. aureus presented high resistance to antimicrobial agents, with continuous monitoring of endotracheal secretion and its rapid identification in the search for better management of antibiotic therapy and invasive procedures.