Distribution and change in antimicrobial resistance of bacteria from sputum of patients in respiratory intensive care unit

Abstract:

ObjectiveTo investigate the distribution and antimicrobial resistance of bacteria isolated from sputum of patients in respiratory intensive care unit (RICU). MethodsNonrepetitive bacteria isolated from sputum specimens of 557 hospitalized patients in RICU of a tertiary firstclass hospital between January 2013 and December 2015 were collected, antimicrobial resistance of bacteria was analyzed. ResultsA total of 1 131 bacterial strains were isolated, 212(18.8%) were grampositive bacteria and 919(81.2%) were gramnegative bacteria. The top five species were Acinetobacter baumannii (30.2%), Pseudomonas aeruginosa (21.1%), Staphylococcus aureus (18.2%), Klebsiella pneumoniae (9.8%), and Serratia marcescens (8.3%). In 20132015, isolation rate of Staphylococcus aureus and nonfermentative bacteria showed no obvious changing tendency, but isolation rate of Enterobacteriaceae strains had increasing tendency. Antimicrobial susceptibility testing results showed that Acinetobacter baumannii and Pseudomonas aeruginosa exhibited high resistance rates to imipenem, levofloxacin, and gentamicin (all >60%), resistance rate of Pseudomonas aeruginosa to ceftazidime showed a downward trend (from 59.4% to 37.5%); isolation rate of methicillinresistant Staphylococcus aureus (MRSA) was 96.1%, susceptibility to tigecycline, vancomycin, linezolid, compound sulfamethoxazole, quinupristin/dalfopristin were almost 100%; resistance rates of Enterobacteriaceae strains to sulfonamide decreased from 55.6% to 14.3%，but resistance rates to ceftazidime, cefotaxime, imipenem, levofloxacin, and gentamicin were all >60%. ConclusionThe major bacteria isolated from sputum of patients in RICU are Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus, antimicrobial resistance of isolated bacteria is serious.