The Frequency of Extended Spectrum Beta-Lactamase in Escherichia coli and Klebsiella pneumoniae Strains Isolated from Health-Care Associated Infections: A Four-Year Study

Introduction: Extended spectrum beta-lactamase production is detected more frequently in members of the Enterobacteriaceae family, especially in Escherichia coli and Klebsiella spp. strains. In this study, it was aimed to investigate ESBL frequency in E. coli and Klebsiella pneumoniae strains isolated from health-care associated infections. Materials and Methods: Patients admitted to our hospital between January 2014-December 2017 with the diagnosis of “health care associated infection” according to Centers for Disease Control and Prevention criteria were retrospectively reviewed. Double disc synergy method was used to evaluate ESBL positivity in E. coli and K. pneumoniae strains isolated from the clinical samples of these patients. Results: A total of 621 E. coli and K. pneumoniae strains (151 strains in 2914, 214 strains in 2015, 129 strains in 2016 and 127 strains in 2017) isolated from health-care associated infections were included into the study. ESBL positivity was detected as 60.8% in 2014, 71.1% in 2015, 72.7% in 2016 and 65.0% in 2017 for E. coli strains and 38.7% in 2014, 52.7% in 2015, 38.4% in 2016 and 25.5% in 2017 for K. pneumoniae strains, respectively. Conclusion: It is important to define ESBL production correctly in the laboratory to enhance success in the treatment of infections that have these enzymes