Distribution and antimicrobial resistance of pathogens causing bloodstream infection in patients with hematological diseases in 2012-2016

Abstract:

ObjectiveTo understand clinical characteristics, pathogenic distribution and antimicrobial resistance of bloodstream infection(BSI) in patients with hematological diseases, so as to provide evidence for rational application of antimicrobial agents.MethodsClinical data of hematological patients with BSI from January 2012 to December 2016 were retrospectively analyzed, including infection site, species of pathogens, resistance to commonly used antimicrobial agents and so on.ResultsA total of 308 patients were with BSI, 337 strains of pathogens were isolated from blood culture, 119 (35.3%) of which were grampositive bacteria, mainly coagulasenegative staphylococcus and Enterococcus; 215 strains(63.8%) were gramnegative bacteria, mainly Escherichia coli(E. coli), Klebsiella pneumoniae(K. pneumoniae), and Pseudomonas aeruginosa(P. aeruginosa); 3(0.9%) were fungi, all were Candida tropicalis. The proportion of gramnegative bacteria isolated from patients with BSI increased gradually, up to 71.6%. Resistance rates of E. coli and K. pneumoniae to cefoperazone/sulbactam, piperacillin/tazobactam, and carbapenems were all<20%. Resistance rates of P. aeruginosa to amikacin, ciprofloxacin, cefoperazone/sulbactam, piperacillin/tazobactam, and carbapenems were all<20%. Susceptibility rates of major grampositive bacteria to vancomycin, teicoplanin, and linezolid were close to or up to 100%, vancomycinresistant Enterococcus (VRE) was not found. Susceptibility rate of Candida tropicalis to amphotericin B was 100%. The detection rates of extendedspectrum βlactamases in E. coli and K. pneumoniae were 55.6% and 41.2% respectively. Five strains of methicillinresistant Staphylococcus aureus were detected among 8 strains of Staphylococcus aureus, and 86.7% of 60 strains of coagulasenegative staphylococcus were methicillinresistant staphylococcus.ConclusionThere are many kinds of pathogens causing BSI in hospitalized patients with hematological diseases, proportion of gramnegative bacteria has increasing tendency, detection rate of multidrugresistant organisms is high, antimicrobial agents should be selected rationally based on the distribution and drug resistance of pathogens in different regions.

Key words:

hematological disease; bloodstream infection; pathogen; drug resistance; healthcareassociated infection