Bacterial Pathogens Differed Between Neutropenic and Non-neutropenic Patients in the Same Hematological Ward: An 8-Year Survey

Background. Bacterial infections are very common among patients with hematological diseases. Scant data are available regarding differences in the epidemiology and biological features of bacterial infections in neutropenic and non-neutropenic patients. Methods. The aim of this survey was to compare the bacterial pathogens in neutropenic and non-neutropenic patients in the same ward during an 8-year period. Results. A total of 1139 bacterial strains were isolated from 1071 patients with hematological diseases. The percentage of Gram-negative bacteria was significantly higher in neutropenic patients than in non-neutropenic patients (70.4% vs. 55.0%, respectively, P < .01). In neutropenic patients, the most commonly-isolated bacterium was Pseudomonas aeruginosa, followed by Klebsiella pneumoniae, Escherichia coli, Acinetobacter baumannii, and Stenotrophomonas maltophilia. In respiratory exudates, Gram-negative bacteria were also more frequently isolated from neutropenic patients than from non-neutropenic patients (79.1% vs. 56.1%, respectively, P < .01). The proportion of non-fermentative Gram-negative bacilli was significantly higher in neutropenic patients than in non-neutropenic patients (52.9% vs. 30.5%, respectively, P <.01). In blood culture samples from neutropenic patients, the most frequently identified pathogens, apart from coagulase negative staphylococcus, were Gram-negative bacilli (58.2%). In addition, the proportion of Escherichia coli in neutropenic patients was significantly higher than that in non-neutropenic patients (P <.01). Escherichia coli and Klebsiella pneumoniae strains from neutropenic patients also produced extended-spectrum beta-lactamases at a higher rate of than those strains from non-neutropenic patients (Escherichia coli, 57.6% vs. 30.3%, respectively, P <.01; Klebsiella pneumonia, 31.9% vs. 13.0%, respectively, P <.01). Conclusions. This study showed that there are significant differences in the epidemiology and biological features of bacteria isolated from neutropenic and non-neutropenic patients.