Corynebacterium pseudodiphtheriticum isolated from relevant clinical sites of infection: a human pathogen overlooked in emerging countries.

AIMS: To examine the occurrence of and to determine the antimicrobial susceptibility of Corynebacterium pseudodiphtheriticum among patients with bacterial infections at a teaching hospital.

METHODS AND RESULTS: A total of 113 Coryne. pseudodiphtheriticum strains identified by conventional biochemical methods and API-Coryne System were recovered from patients from different age groups: 65.48% adults (18 to < or =59 years old), 9.73% aged (> or =60 years old); 14.15% infants (<18 years old); 4.42% newborns (0-7 days). Micro-organisms were mostly related to infections in the urinary (29.2%) and respiratory tracts (27.45%) and intravenous sites (18.6%). Clinical samples were obtained only from 32.7% patients (26 adults, four aged, four infants and three newborns) presenting at least one of the predisposing conditions: end-stage renal disease; renal transplant; AIDS and Mycobacterium tuberculosis infection; cancer, hepatic cirrhosis; haemodialysis and catheter use. Antimicrobial susceptibility tests identified multiresistant phenotypes. Most strains (>50%) were resistant to oxacillin, erythromycin and clindamycin.

CONCLUSIONS: Despite significant differences in age and functional status of patients Coryne. pseudodiphtheriticum may be implicated as a cause of respiratory and nonrespiratory human infections.

SIGNIFICANCE AND IMPACT OF THE STUDY: Data are valuable for practitioners indicating the occurrence of multiresistant phenotypes and the possibility of severe infections due to Coryne. pseudodiphtheriticum, a pathogen usually overlooked in emerging countries.