RESUMEN
In this study, it was aimed to determine the possible factors affecting the clinical importance of Corynebacterium striatum isolates, which were accepted as infectious or contamination/colonization agents, by comparing their clinical and microbiological characteristics, antimicrobial susceptibility results, biofilm forming abilities and genotypic characteristics. The patients with C.striatum growth in the clinical samples sent to the laboratory were evaluated as infection or contamination/colonization with the evaluation of the examination findings and other laboratory parameters by the relevant physician. This study included 58 isolates, 29 of which were considered as infection and 29 as contamination/colonization. Length of hospital stay, presence of underlying disease [diabetes mellitus (DM), neurological disease, ischemic heart disease, chronic kidney disease, solid tumor], surgical operation status in the last month, and antibiotic use in the last three months of the patients were examined. Identification of the bacterial type was made with MALDI-TOF MS (Bruker/Germany) system. Antimicrobial susceptibility tests were performed by disc diffusion and gradient diffusion method and evaluated according to EUCAST standards. Biofilm production was determined in 96-well microtiter plates on negatively charged polystyrene surfaces. Clonal analyzes were performed by PFGE method using Xba1 enzyme. It was observed that there was no difference in terms of demographic characteristics in the two patient groups included in the study. It was observed that C.striatum strains isolated from outpatients were mostly found in the contamination/ colonization group. The presence of diabetes mellitus, ischemic heart disease, chronic kidney disease and solid tumor was not statistically different in the two patient groups. It was observed that C.striatum strains grown in the samples of patients with neurological disease were mostly found in the infectious agent group (p= 0.025). It has been observed that C.striatum strains grown purely in culture were mostly found in the infectious agent group (p= 0.001). Biofilm production was found to be significantly higher in the infectious agent group (p= 0.015). In antimicrobial susceptibility tests, it was observed that there was widespread multidrug resistance (MDR) in both groups and there was no significant difference between the groups in terms of antimicrobial susceptibility. In our study, it was determined that the strains showed very different PFGE patterns and were not clonally related to each other. In this study, it was determined that the demographic characteristics and comorbidities of the patients were not helpful in evaluating the clinical significance of C.striatum. Biofilm production was observed to be a common virulence factor in C.striatum strains. It was thought that there may be difficulties in the treatment of C.striatum in the future due to the widespread MDR detection among this bacterium strains. Our study contributes to draw attention to the increase in C.striatum infections, resistance and virulence factors.