| Objective To analyse the characteristics of pathogen distribution and drug susceptibility to antibacterial agents of bacterial infection in hematology hospitalized patients admitted to our hospital from 2010 to 2014;also reviewed in pre-engraftment phase the clinical feature of infection in the patients after undergoing hematopoietic stem cell transplantation(HSCT),to expore the ralationship of bacterial infection and the type of stem cell transplant,graft-versus-host disease(GVHD),earlier death.Methods The microbiological data from the patients admitted to hematological unit from January 2010 to December 2014.Antimicrobial susceptibility test was done by Kirby-Bauer method and automated systems meanwhile the data was analysed by WHONET 5.6.Etiologic feature and the changes of drug resistance pattern of bacterial infection in pre-engraftment phase were retrospectively reviewed in the patients after undergoing hematopoietic stem cell transplantation and the clinical data were statistically analysed by IBM SPSS17.0.Results From January 2010 to December 2014 the culture-positive specimens were 634(19.14%)in all of 3312 samples from hematological patients. Among it,blood sample were 488,the rest were sputum specimens. 207 strains(32.65%) were gram-positive cocci and 427(67.35%) were gram-negative bacilli.The former mainly contained coagulase negative Staphylococcus(CNS),Streptococcus,Enterococcus,while Escherichia coli,Klebsiella pneumoniae, Pseudomonas aeruginosa were the three most bacterial isolates from the latter and non-fermentative bacteria gradually increased year by year.The resistant rates to imipenem, piperacillin/tazobactam, cefoperazone/sulbactam(CPZ/SB) and amikacin of Escherichia Coli were 0.8%,13.7%,17.1% and 12.9% respectively, compared with 11.8%,11.8%,33.3% and 8.8% for Klebsiella pneumoniae.The two bacteria above-mentioned had a higher resistant rate was between 41.2% to 86.7% to cephalosporins. Detection rates of Extended-spectrum beta-lactamases(ESBLs) in Escherichia coli and Klebsiella pneumoniae were 83.9% and 75%.The resistant rate of Pseudomonas aeruginosa to imipenem was 3.3%, to ceftazidime was 6.7% equal to piperacillin/tazobactam,and to cefoperazone/sulbactam was zero. The sensitivity rate of Acinetobacter baumannii was 18.2% to imipenem, was 100% to cefoperazone/sulbactam.Penicillin(G) –resistant strains in Staphylococcus aureus(SA)and coagulase negative Staphylococcus(CNS) accounted for 100% and 87.5% respectively,while Methicillin-resistant strains in S.aureus(MRSA) and MRCNS accounted for 20% and 65.9% separately.The resistant rate to quinolones of Enterococcus faecium strains was 96.2%-100%. No vancomycin and/or linezolid and/or tigecycline resistant strains of Staphylococcus spp. and Enterococcus spp. were found in hematological patients.Among 414 HSCT recipients reviewed in our department in the corresponding period,98 patients had microbiologically-documented microorganisms isolated with 113 positive samples dominated by Gram-negative bacterium(75.22%) mainly withEscherichia coli and Klebsiella pneumoniae which basically were resistant strains. Conversely, coagulase negative Staphylococcus(CNS) and Enterococcus faecium strains which isoloted were all drug-sensitive strains. 33 patients(7.47%) died from infection after transplantation.The infection rate of patients received transplantation from umbilical cord blood(UCB) was higher than recipients from bone marrow transplantation or peripheral blood stem cell transplantation(χ2=21.062,P=0.000); furthermore, the bacteria infection rate of recipients from UCB with a GVHD was higher than those without a GVHD(χ2=7.233,P=0.07), with statistical significance.Conclusion Hematology have a higher incidence of bacterial infections and Gram-negative bacilli was the major pathogen.Drug-resistant strains gradually increased in the HSCT patients.Our results may have relevant value in the empirical use of antimicrobial agents for the treatment of infections in patients with hematological disease and effective prevention or treatment of infectious complications after hematopoietic stem cell transplantation. |
PDF Full Text Request