[Distribution and Drug Sensitivity of Pathogens Causing Nosocomial Infection in Patients with Hematological Granulocytosis].

Objective: To investigate the distribution and drug resistance of nosocomial infection pathogens in AL patients with hematological agranulocytosis, so as to provide evidence for the clinical rational use of antibiotics.

Methods: Pathogenic data of 504 hospitalized patients with agranulocytosis caused by nosocomial infection in the Department of Hematology, the First Hospital of Lanzhou University from May 2015 to May 2018 were collected and retrospectively analyzed for the distribution of pathogenic bacteria and the results of drug susceptibility.

Results: The isolated pathogenic bacteria strains amounted to 184, out of which, 168 strains (91.3%) orginated from the patients with acute leukemia, while 16 strains (8.7%) originated from the patients with non-acute leukemia. The positive samples mainly originated from blood stream, the isolated bacteria from which were 81 straims (44%); then originated from sputam and pharynx swabs, from which isolated bacteria amounted to 54 strains (29.3%) and 35 strains (19%) respectively. In the pathogenic bacteria, the Gram-negative bacteria amounted to 126 strains accounting for 68.46%, out of which the most commond bacteria strains were Klebseilla pneumoniae, cscherichia coli and Pseudomonas aeruginosa; the Gram positive bocteria amounted to 23 strains accounting for 12.5%, mainly staphy lococeus anreus, and Staphylococcus epitermidis; the fungi amounted to 35 strains accounting for 19.02%, mainly Candida albicans. The detection rates of Escherichia coli and Klebsiella pneumoniae producing extended-spectrum β-lactamases (ESBLs) were 40.0% and 22.2%, respectively. They were 100% sensitive to amikacin and 27.8% resistant to carbapenems. Klebsiella pneumoniae had the highest sensitivity to amikacin, 94.44% to ampicillin, 97.22% to carbapenems and 100% sensitive to ammonia. Their penicillin-resistance rate was the highest, up to 80%; Pseudomonas aeruginosa was sensitive to the antibiotics (＞80%）. Methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococcus were detected in Gram-positive bacteria. The susceptibility rate of main Gram-positive bacteria to vancomycin and linezolid was 100%, and they were 100% resistant to penicillin.

Conclusion: Gram-negative bacteria are the main pathogens of nosocomial infection in patients with hematological agranulocytosis. Pathogens have different resistance to antimicrobial agents. It is important to know the distribution and susceptibility of common pathogens for rational selection of antimicrobial agents and control of nosocomial infection.