Identification and resistant gene detection with genotyping in blood cultures with gram positive bacteria growth

Rapid identification of the bacteria and antibiotic resistance causing sepsis is very important. Beginning with the appropriate treatment as soon as possible reduced morbidity/mortality, shortened the hospitalization time, prevented the unnecessary antibiotic use and reduced the hospital costs. Automated blood culture systems have significantly reduced the identification time of bacterial pathogens. However, faster identification systems are required to begin the right treatment as early as possible. The aim of this study is identification and resistant gene detection (mecA gene and vanA, vanB, vanC1, vanC2/C3 genes that cause methicillin and vancomycin resistance) with genotyping method (Genotype® BC Gram-positive) in blood cultures with gram positive bacteria growth which were obtained from inpatient from Düzce University Hospital's services.The study included a total of 72 Gram positive bacteria (which are 45 CNS, 17 S. aureus,9 Enterococci and one S. group D) identified in blood culture samples. Genotyping revealed a total of 49 CNS of which 37 (75%) is mecA positive; a total of 17 S.aureus of which 9 (52.9%) is mecA positive; a total of 10 enterococci of which 2(20%) vanA positive; 2 S.pneumoniae and 2 S. mitis / oralis. Two S. pneumoniae and 2 S. mitis / oralis which could not be detected in the culture, were determined by genotyping method. In the statistical evaluation performed as a result of genotyping study; there was a significant correlation between bacterial culture and genotyping methods for all bacterial species (p = 0.999).Using the BC Gram positive test, sepsis causative bacteria from blood culture bottles and resistance genes of these bacteria were detected correctly within 4-5 hours. For this reason it was found that genotyping may contribute to early clinical diagnosis and treatment of sepsis patients. However, in our study, genotyping method was not found in 10 samples with bacteria detected in culture. Therefore, it is thought that the use of culture and molecular methods together is very important in the diagnosis of sepsis. Key words: Sepsis, Blood culture, Genotypic tests, Gram positive cocci, mecA, van Genes, rapid molecular testing.