Extended-spectrum beta-Lactamase (ESBL) producing bacteria isolated from blood culture in thai hospitals from 2007-2012

Abstract

Background: Antibiotic resistance in bacteria is a major public health problem. The resistance rates increase every year due to the evolution of bacteria and misuse of antibiotics. The objective of this study was to determine ESBL strains of the most common 2 gram-negative bacteria isolated from blood culture, Escherichia coli and Klebsiella pneumoniae. Methods: We conducted blood stream infection surveillance in Sa Kaeo and Nakhon Phanom by using automated blood culture system. We performed disks diffusion assay following the criteria of the Clinical Laboratory Standards Institute (CLSI) for positive culture. Blood specimens were collected from all hospitals as clinical indicated sepsis. Results: From 2007-2012, a total 11,846 blood specimens were collected. Gramnegative bacteria were mostly found; 2660 (22.5%) isolates of E. coli and 877 (7.4%) isolates of K. pneumoniae. In 6 years, ESBL producing strains were found in 487 isolates of E. coli (18.3%) and 166 isolates of K. pneumoniae (18.9%). The percentage of E.coli ESBL producing bacteria increased from 5.5% in 2007 to 25.0% in 2012, similar to those of K. pneumoniae which rose from 13.6% in 2007 to 22.4% in 2012. ESBL producing strains showed more than 90% susceptibility to Ertapenem, Imipenem, Meropenem and Amikacin. Conclusions: The percentage of antibiotic resistance E. coli and K. pneumoniae increased from 2007 to 2012 which lead to problems in treatment and management in hospitals. The drug of choice for ESBL producing strains are carbapenem and aminoglycoside (only Amikacin). This study emphasizes the urgency to control and monitor antibiotic resistance bacterial pathogens. N