Perfil epidemiológico, susceptibilidade antimicrobiana e virulência de microrganismos corineformes isolados de pacientes hospitalizados

Abstract

Health care associated infections have become a serious problem of public health worldwide. Corynebacterium species have been reported with increasing frequency as nosocomial pathogens, especially in immunocompromised patients. In this perspective, this study aimed to identify coryneform microorganisms isolated from patients hospitalized in a referral hospital in the mountainous region of Rio de Janeiro, determine the profile of sensitivity of these microorganisms, and evaluate these strains potential to adhesion in HEp-2 cells. Thus, 214 samples from individuals hospitalized and various clinical samples were analyzed by traditional phenotypic methods. The data indicated the presence of 09 irregular Gram-positive bacilli. The strains were isolated from the following clinical samples: bronchoalveolar fluid (06 strains), surgical wound secretion (01 strain), blood culture (01 strain), and vaginal secretion (01 strain). Conventional phenotypic characterization has not completed the identification of the isolates. The final identification was performed by Maldi-Tof technique, which identified 100% of genus and species stains. The data indicated the presence of four Corynebacterium accolens (44.45%), three Corynebacterium amycolatum (33.35%), one Corynebacterium minutissimum (11.10%), and one Corynebacterium falsenii (11.10%). Susceptibility profiles to antimicrobials were performed by disk diffusion test agar (Kirby-Bauer). The isolates exhibited heterogeneous susceptibility profiles to antimicrobials. Corynebacterium amycolatum (stains 28, 59B and 134) and Corynebacterium accolens (stain 80) showed multiresistance profiles. Two isolates (samples 28 and 134) showed imepenem resistance, and were valued of the production of metallo-beta-lactamase by disk method approach. The metallo-beta-lactamase was detected in both. To test the samples as their adhesion capacity, HEp-2 cells were submitted a period of 3 hours to infection at 37ºC. All strains were able to adhere in HEp-2 cells. The most frequent phenotype was aggregative adhesion (71%), predominant in C. amycolatum. This study provides important epidemiological data of prevalence of infections caused by corynebacteria in the mountainous region of Rio de Janeiro. It contributes to the knowledge of the antimicrobial susceptibility profile of commonly underestimated microorganisms as etiological agents of human infections. It addresses the mechanisms of adhesion involved in these infections, and highlights the need for health professionals to remain alert to the possibility of infectious by Corynebacterium spp. in different body sites, in the hospital environment, especially multidrug-resistant samples to antimicrobials commonly used in clinical routine.