[Pathogen distribution and antimicrobial resistance among lower respiratory tract infections in patients with hematological malignancies]

Objective: To investigate the pathogen distribution and antimicrobial resistance among lower respiratory tract infections in patients with hematological malignancies. Methods: Sputum samples were collected from 967 patients with hematological malignancies and lower respiratory tract infections in Department of Hematology,the Second Hospital of Shanxi Medical University from January 2017 to July 2020. The pathogens and drug sensitivity reports were carried out by automatic bacterial identification instruments. WHONET 5.6 and SPSS 20.0 softwares were used for statistical analysis. Results: A total of 961 strains of pathogens were isolated, 516 (53.7%) pathogens were Gram-negative bacteria, mainly 118 strains of Klebsiella pneumonia (12.3%), 68 strains of Pseudomonas aeruginosa (7.1%), 67 strains of Acinetobacter baumannii (7.0%),52 strains of Stenotrophomonas maltophilia (5.4%), 43 strains of Escherichia coli (4.5%), and 42 strains of Enterbacter cloacae (4.4%). There were 171 (17.8%) strains of Gram-positive bacteria and 274 (28.5%) fungi. The drug resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannii to carbapenem were 22.1%-31.3%. Stenotrophomonas maltophilia was sensitive to levofloxacin, compound sulfamethoxazole and minocycline. The antimicrobial resistance rates of these three enterobacteria to carbapenems, cefoperazone/sulbactam, piperacillin/tazobactam were low (<10%). The resistant Gram-positive bacteria to ticoplanin, vancomycin and linazolamide were not detected. Conclusion: The major pathogens related to lower respiratory tract infections in patients with hematological malignancies are gram-negative bacteria in our centre. Different pathogens appear different characteristics of antimicrobial resistance.