Clinical analysis of 74 cases of bloodstream infections caused by multidrug-resist-ant Acinetobacter / 中国感染与化疗杂志

ABSTRACT

Objective To study the clinical characteristics,antimicrobial restistance of bloodstream infections (bacteremia) caused by multidrug-resistant Acinetobacter and analyze the outcomes of antibacterial therapy.Methods The clinical data were reviewed retrospectively for 74 patients with bloodstream infection caused by multidrug-resistant Acinetobacter who were trea-ted in HuaShan hospital from January 2005 to December 2011 .Results During the 6-year period,74 patients were diagnosed with multidrug-resistant Acinetobacter bacteremia,73 of which were nosocomial infections.The remaining one was community-acquired. Primary bloodstream infection accounted for 51 .4% (38/74),and secondary infection 48.6% (36/74), mainly secondary to pulmonary infections (23.0%,17/74). Solid tumor was the most common underlying disease (24.3%,18/74).Prior corticosteroid therapy,indwelling deep venous catheter,surgery and invasive procedures were predisposing factors of bacteremia. Acinetobacter-related bloodstream infections were associated with higher white blood cell count,increased neutrophil percentage,higher APACHE II score and lower serum albumin level.The bloodstream infection was caused by Acinetobacter baumannii in 65 pa-tients,Acinetobacter lwoffi in 7 patients,both Acinetobacter baumannii and Acinetobacter junii in one patient.The all-cause mortality rate was 27.0% (20/74).In vitro susceptibility testing showed that 20.0% (15/75 )of the Acinetobacter isolates were resistant to cefoperazone-sulbactam,which was the lowest among all the antibiotics tested.About 40.0% to 42.7% of the isolates were resistant to carbapenems.The outcome was related to the antimicrobial restistance.Carbapenem non-suscepti-ble Acinetobacter was associated with poorer outcome compared with carbapenem-susceptible Acinetobacter (mortality 46.9%vs 11 .9%,P <0.05 ).Cefoperazone-sulbactam non-susceptible Acinetobacter was also associated with poorer outcome com-pared with cefoperazone-sulbactam susceptible Acinetobacter (mortality 40.0% vs 18.2%,P <0.05).Of the 32 patients who had infections with carbapenem-non-susceptible Acinetobacter,20 received sulbactam-containing antimicrobial agent.The mor-tality of these 20 patients was 20.0% (4/20),significantly lower than that of the 12 patients who did not receive sulbactam-containing antimicrobial agent (66.7%).Conclusions Majority of the bloodstream infections caused by multidrug-resistant Acinetobacter are nosocomial infections.Surgical operation and serious condition may predispose the patients to develop Acine-tobacter bacteremia.Acinetobacter isolates are highly resistant to commonly used antibiotics.The Acinetobacter isolates not susceptible to carbapenem or cefoperazone-sulbactam are associated with poorer outcome and higher mortality.More attention should be paid to prevention and control of Acinetobacter-related nosocomial infections.