Aspectos microbiológicos e clínico-epidemiológicos de cepas de Corynebacterium spp. isoladas em laboratórios da rede privada localizados na região metropolitana do Rio de Janeiro

Abstract

In the present study, microbiological and clinical-epidemiological aspects of Corynebacterium spp. strains collected from various clinical materials and diagnosed in a laboratory of the private network from Rio de Janeiro metropolitan area were investigated. Samples of Irregular Gram-positive rods (IGPRs) isolated were analyzed by using the MALDI-TOF. Susceptibility to antimicrobial agents (n=5) was evaluated by the disk-diffusion technique (BrCAST) and the search for the presence of tox gene by multiplex PCR technique. During the two-year period of study, were isolated fifty-one Corynebacterium spp. strains from clinical materials of female and male patients of all age groups teated in several hospital units (64.70%) and outpatients (35.29%) from the metropolitan region. Analysis using the MALDI-TOF technique identified 84.31% Corynebacterium species: C. striatum (n=13; 25.49%), C. amycolatum (n=10; 25.49%) C. xerosis (n=6; 19.60%), C. pseudodiphtheriticum (n=3), C. jeikeium (n=2), C. tuberculostearicum (n=2), C. urealyticum (n=2), C. minutissimum (n=2), C. imitans (n=1) and C. simulans (n=1). Some strains (15.69%) were identified as C. amycolatum/C.xerosis (n=3) and Corynebacterium sp.(n=5). C. diphtheriae not producing diphtheria toxin was diagnosed in the laboratory in case of tonsil abscess. All strains of Corynebacterium spp. demonstrated sensitivity to linezolid and vancomycin and heterogenic resistance profiles to penicillin, ciprofloxacin and gentamicin. MDR profiles were detected in only three samples: C. striatum, C. urealyticum and C. imitans. Most Corynebacterium spp. strains were isolated from blood (49.1%) and urine (13.72%). In conclusion, hospital and community infections caused by several Corynebacterium species occur in the metropolitan region of Rio de Janeiro as well as in several countries. Our data emphasize previous studies that described C. striatum and C. amycolatum as one of the main pathogens responsible for infections and/or nosocomial outbreaks, including in Brazil. Therefore, IGPRs strains must be properly isolated and identified, and should not be considered only as commensal bacteria of the skin and mucous membranes and discarded as contaminants strains. Pathogens of the Corynebacterium genus cannot be underestimated, especially in countries where classic diphtheria remains endemic, including Brazil, and epidemic outbreaks have been occurring in several countries, in addiction to the emergence of zoonotic diphtheria, in Brazil and worldwide.