Characteristics and Clinical Outcomes of Extended-Spectrum beta-lactamase-producing Klebsiella pneumoniae Bacteremia in Cancer Patients

Background: Cancer patients can be at a higher risk of infection due to drug-resistant bacteria than the general population for various reasons. We performed a retrospective study to evaluate possible risk factors and outcomes of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) bacteremia in cancer patients. Materials and Methods: Cases were divided into two groups based on whether or not the isolated strain produced ESBL and multivariable regressions were done to identify possible risk factors of ESBL-KP bacteremia and mortality. For ESBL-producing strain, additional molecular analysis was done. Results: 278 cases with KP bacteremia were identified between 2010 and 2012, of which ESBL-producers were 50 (18%). The presence of percutaneous drainage catheter [odds ratio (OR) 4.99, P <0.001] and prior exposure to certain classes of antibiotics including third-generation cephalosporin (OR 2.14, P = 0.03) had significant associations with ESBL-KP bacteremia. Individuals who died within 14 days after the onset of KP bacteremia were more likely to have higher mean Pitt bacteremia score (1.56 in survival group vs. 3.43 in mortality group, P <0.001), hemodialysis (OR 17.03, P = 0.01) and chronic liver disease (OR 5.57, P = 0.01). Although 14-day mortality was higher with ESBL production (OR 2.76, P = 0.04), no significant differences in 30day mortality (OR 1.67, P = 0.20) and other morbidity indices were observed. 49 ESBL-KP isolates, 65.4% of them produced CTX-M-14 and CTX-M-15 enzymes, and ST711 was the most common. Conclusion: There were several differences in clinical characteristics between ESBL-KP and non-ESBL-KP bacteremia in cancer patients, similar to previous reports including non-cancer patients.