Aspectos microbiológicos e epidemiológicos de amostras de Corynebacterium spp. isoladas de pacientes com infecções hematogênicas internados em diversos hospitais da rede pública e privada localizados na região metropolitana do Rio de Janeiro

Abstract

Corynebacterium spp can be part of the microbiota of human skin and mucous membranes. Corynebacterial infections are gaining importance in both industrialized and developing countries. However, the pathogenicity of corynebacteria remains underestimated, including in Brazil. The growing number of cases of infections of different origins has demonstrated the increased interest in these pathogens. Among the predisposing factors for infections by Corynebacterium spp, malignancy states, advanced age, hospitalization and/or antibiotic therapy for a prolonged period, among others, stand out. Recently, the occurrence of bacteremia has been associated with patient morbidity and mortality. Antibiotic therapy is essential, and treatment cannot wait for a long period of time for isolation, identification and the susceptibility profile of the microorganisms involved. Empiric antibiotic therapy is often used in the treatment of corynebacteriosis. However, the high rate of antimicrobial resistance among Corynebacterium spp. sometimes leads only to the use of vancomycin as the drug of choice. In Rio de Janeiro, isolation of corynebacteria from patients treated at a university hospital, mainly from urine and intravenous sites, has been reported. Additionally, a nosocomial outbreak was caused by multidrug-resistant strains of Corynebacterium striatum. The laboratory identification of Corynebacterium spp remains a challenge for routine diagnosis. Therefore, the present study has as general objective the retrospective and prospective analysis of microbiological and epidemiological aspects of samples of Corynebacterium spp. isolated from patients with hematogenous infections hospitalized in several public and private hospitals in the metropolitan region of Rio de Janeiro. During the two-year period of the study, 64 clinical samples were isolated from blood cultures and identified as Corynebacterium spp in a clinical laboratory with extensive care in the private network. The MALDI-TOF technique allowed the identification of samples of the genus Corynebacterium spp and the characterization of several species isolated from blood cultures with greater speed and precision. Most samples were identified at the species level (n= 51; 78.46%). However, 13 samples were partially identified as Corynebacterium spp (21.53%). The identified species were (n=10), C. striatum (n=17; 24.61%), C. amycolatum (n=12; 15.38%), C. jeikeium (n=5; 9.26% ), C. urealyticum (n=6; 9.26%), C. aurimucosum (n=5; 7.69%), C. simulans (n=2), C. colyeae (n=1), C. tuberculostearicum (n=1), C. pseudodiphtheriticum (n=1) and C. minutissimum (n=1). A greater number of cases were observed in elderly and female patients, in addition to three cases in neonates. The expression of MDR profiles of the tested samples was observed mainly in C. striatum, C. urealyticum besides C. jeikeium. The improvement of laboratory techniques contributes to the diagnosis of infections caused by Corynebacterium spp. mainly reducing the spread of multi-drug resistance and nosocomial infections