Flora Infeksiyon Hastalıkları ve Klinik Mikrobiyoloji Dergisi (Dec 2013)
The Prevalence of Extended-Spectrum Beta-Lactamase and Antibiotic Resistance among Escherichia coli and Klebsiella pneumoniae Isolates Responsible for Nosocomial Blood-Stream Infections
Abstract
Introduction: This study aimed to identify the extended-spectrum beta-lactamase (ESBL) production prevalence of Escherichia coli and Klebsiella pneumoniae strains isolated from nosocomial bloodstream infections as well as their resistance to the antibiotics used. Materials and Methods: This study examined the E. coli and K. pneumoniae strains isolated from blood-stream infections at the Health Care and Research Hospital, Faculty of Medicine, Cumhuriyet University, between 2009 and 2012. Strain description and antimicrobial susceptibility tests were carried out using an automated system (BD, Phoenix, AZ, USA) based on the recommendations of the Clinical and Laboratory Standards Institute (CLSI). Results: This study examined 321 E. coli and 104 K. pneumoniae strains isolated from nosocomial blood-stream infections. ESBL was found in 38.3% of E. coli strains and in 26.9% of K. pneumoniae strains isolated from blood cultures. No resistance was found in any strains to carbapenems. Amikacin was considered to be the second-least resistant antibiotic for these strains. One hundred and thirtyfour of the 425 nosocomial strains were isolated from intensive care units and 291 from other services. Fifty-six percent of strains isolated from intensive care units were found to be E. coli and 44% as K. pneumoniae. ESBL was found in 57.3% of E. coli and 30.5% of K. pneumoniae strains isolated from intensive care units, and this ratio was found to be 32.5% and 22.2%, respectively, for other units. Conclusion: Increasing rates of resistance are being reported worldwide in studies carried out with E. coli and K. pneumoniae strains raising future concerns. Thus, resistance data should be constantly updated. We conclude that the local data gathered in this study can be used in the fight against relevant bacterial nosocomial bloodstream infections and can be effective in creating successful empirical treatment models and preventing the spread of such microorganisms.
