Antimicrobial Resistance of Microorganisms Causing Pneumonia in Patients of a Public Hospital in Brazilian Pre-Amazon Region

Nosocomial infections have been common in health services in Brazil. Among them, pneumonia is very highlighted due to the comorbidity that usually affects intensive treatment unit (ITU) patients, and due to the need for endotracheal intubation. The aim of this study was to determine the resistance profile of bacteria isolated from ITU patients with pneumonia in a public hospital in São Luis, an important city in the Brazilian pre-Amazon region. Bacteria strains were obtained from tracheal aspiration and collected for diagnosis as well for phenotypic characterization. Standards culture media, such as blood and MacConkey agar, were used to isolate clinical strains. Automatized Vitek 2 method was used to identify strains and disc diffusion method (Kirby-Bauer) was performed to determine the antimicrobial susceptibility profile. During study, eighty-eight patients were diagnosed with pneumonia, caused by more than 20 different bacteria. Among them, P. aeruginosa (28%), Acinetobacter baumannii (20%), Coagulase-negative Staphylococci (19%), Staphylococcus aureus (8%) and Klebsiella pneumoniae (7%) were the most prevalent microorganisms. Regarding to the resistance, antimicrobial susceptibility test showed that majority of Gram-negative bacteria presented resistance to ampicillin. In Gram-positive bacteria there was a high resistance to ampicillin, penicillin, ciprofloxacin, clindamycin and erythromycin. This study showed a high prevalence of bacteria resistance in ITU patients in a public hospital. Although P. aeruginosa was the most frequent pathogen, it was possible to find other pathogens that were not recurrent, such as Enterobacter spp., Proteus mirabilis and Providencia stuartii. Regarding antimicrobials, the results showed a high resistance to several antimicrobials.