[Analysis of the distribution characteristics and drug resistance of non-fermenting bacterial infection in intensive care unit from 2009 to 2015]

Abstract

Objective: To study the distribution characteristics and drug resistance of non-fermenting bacterial infection in intensive care unit (ICU) at a tertiary hospital during seven consecutive years, and to provide evidence for rational use of antibiotics in ICU.

Methods: A retrospective analysis was conducted. The related data about non-fermentative bacteria obtained from clinical specimens, collected from lower respiratory tract, blood, urine, bile and other secretions of ICU patients admitted to Binzhou Medical University Hospital from January 2009 to December 2015 were retrospectively analyzed. The distribution characteristics and drug resistance of non-fermentative bacteria, and isolation rate of multiple drug resistance (MDR) strains were analyzed.

Results: 2 672 strains of nonfermentative bacteria were isolated during seven consecutive years, accounting for 57.9％ gram negative (G-) bacilli (2 672/4 613),and 35.2％ of all bacteria (2 672/7 587).The top five were Acinetobacter baumannii (38.4％),Pseudomonas aeruginosa (34.6％),Onion burkholderia cepacia (9.9％),Stenotrophomonas maltophilia (6.2％),and Pseudomonas fluorescens (5.6％).Non-fermentative bacteria were mainly isolated from the lower respiratory tract (60.9％).Isolation of the non-fermentative bacteria accounted for over 50％ of G-bacilli during seven consecutive years, and the isolation rate of the top five types of bacteria showed no obvious change, while positive rate of Acinetobacter baumannii showed a tendency to increase (obviously from 26.5％ in 2009 to 50.2％ in 2015),and a lowering trend of positive rate of Onion burkholderia cepacia,Stenotrophomonas maltophilia, and Pseudomonas fluorescens was obvious (from 15.6％,10.6％,13.0％ in 2009 to 5.6％,7.4％,1.4％ in 2015 respectively) was observed. The isolation rate of Pseudomonas aeruginosa was stable (about 30％) during seven consecutive years. The drug susceptibility results showed that the resistant rates of Acinetobacter baumannii against imipenem, meropenem, aminoglycosides and third-generation cephalmsporins were all higher than 70％,while its resistant rate to cefoperazone-sulbactam was relatively lower (40.2％-68.1％)with relatively higher sensitivity rate (23.6％-46.0％).In contrast, the resistant rates of Pseudomonas aeruginosa against antibiotics were low,while the sensitivity rate to fourth-generation cephalmsporins cefepime (58.3％-87.7％)and third-generation cephalmsporins was high (ceftazidime:55.6％-79.3％,piperacillin-tazobactam:62.5％-86.2％,cefoperazone-sulbactam:46.0％-89.8％).From 2009 to 2015,the incidence of MDR strains of Acinetobacter baumannii showed an obvious increasing tendency (from 68.0％ to 84.1％);in contrast, the incidence of MDR strains of Pseudomonas aeruginosa did not show an obviously increase in incidence from 2009 to 2012,on the other hand, it showed a decreasing tendency from a peak 68.6％ in 2012 to 23.5％ in 2015.

Conclusions: The isolation rate of non-fermentative bacteria was high and the drug resistance situation was serious. Therefore,it is important to grasp the knowledge regarding distribution characteristics, drug resistance and variation of non-fermentative bacteria in ICU. It is not only beneficial for both rational use of antibiotics, improve efficacy but also helpful in reducing the emergence of drug resistance stains.