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 ß-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.