Risk Factors and Impact on Clinical Outcome of Multidrug-Resistant Acinetobacter Baumannii Acquisition in Cardiac Surgery Patients

Published:December 21, 2015DOI:


      Acinetobacter baumannii recently has emerged as an important nosocomial pathogen. The aim of this study was to assess the impact on mortality of multidrug-resistant A. baumannii (MDR-AB) infection/colonization in patients undergoing cardiac surgery and to investigate microbiologic characteristics, epidemiologic spread of this pathogen, and the relative containment measures.


      Single-center, retrospective cohort study of prospectively collected data.


      Cardiac surgery tertiary-care center.


      Patients with positive MDR-AB cultures from September 1, 2009 to December 31, 2011.


      Bivariate and multivariate analyses were performed to individualize the risk factors for MDR-AB-infections in cardiac surgery patients. To evaluate the MDR-AB attributable mortality, a retrospective matched cohort study was performed. Incidence density ratio (IDR) was calculated to compare the MDR-AB infection/colonization before and after the introduction of preventive measures adopted following the first cases.

      Measurements and Main Results

      MDR-AB acquisition occurred in 14 patients (0,6%) of 2385 patients. At the multivariate analyses, preoperative use of inotropic drugs (OR 18.2, 95% CI 4.6-71.9) and logistic EuroSCORE (OR 1.09, 95% CI 1.06-1.13) were found as independent risk factors. Patients with MDR-AB had 57% cumulative in-hospital mortality; no statistical differences in mortality were observed in the matched group. IDR revealed a significantly decreased incidence of infection/colonization (0.3 per 1,000 days of stay compared with 0.03/1,000 days of stay, p = 0.0001) after the containment measures became effective.


      Sicker patients are more susceptible to be infected by A. baumannii, but mortality is not significantly higher compared with other patients with similar characteristics. Adequate measures are fundamental to control the spread of the infection.

      Key Words

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        • Munoz-Price L.S.
        • Weinstein R.A.
        Acinetobacter infection.
        N Engl J Med. 2008; 358: 1271-1281
        • Bergogne-Berezin E.
        • Towner K.J.
        Acinetobacter spp. as nosocomial pathogens: Microbiological, clinical, and epidemiological features.
        Clin Microbiol Rev. 1996; 9: 148-165
        • Mastoraki A.
        • Douka E.
        • Kriaras I.
        • et al.
        Preventing strategy of multidrug-resistant Acinetobacter baumanii susceptible only to colistin in cardiac surgical intensive care units.
        Eur J Cardiothorac Surg. 2008; 33: 1086-1090
        • Jawad A.
        • Seifert H.
        • Snelling A.M.
        • et al.
        Survival of Acinetobacter baumannii on dry surfaces: Comparison of outbreak and sporadic isolates.
        J Clin Microbiol. 1998; 36: 1938-1941
        • Towner K.J.
        Acinetobacter: An old friend, but a new enemy.
        J Hosp Infect. 2009; 73: 355-363
        • Corbella X.
        • Montero A.
        • Pujol M.
        • et al.
        Emergence and rapid spread of carbapenem resistance during a large and sustained hospital outbreak of multiresistant Acinetobacter baumanii.
        J Clin Microbiol. 2000; 38: 4086-4095
        • Theaker C.
        • Azadian B.
        • Soni N.
        The impact of Acinetobacter baumannii in the intensive care unit.
        Anaesthesia. 2003; 58: 261-279
        • Jang T.N.
        • Lee S.H.
        • Huang C.H.
        • et al.
        Risk factors and impact of nosocomial Acinetobacter baumannii bloodstream infections in the adult intensive care unit: A case-control study.
        J Hosp Infect. 2009; 73: 143-150
        • Playford E.G.
        • Craig J.C.
        • Iredell J.R.
        Carbapenem-resistant Acinetobacter baumannii in intensive care unit patients: Risk factors for acquisition, infection and their consequences.
        J Hosp Infect. 2007; 65: 204-211
        • Mathai A.S.
        • Oberoi A.
        • Madhavan S.
        • et al.
        Acinetobacter infections in a tertiary level intensive care unit in northern India: Epidemiology, clinical profiles and outcomes.
        J Infect Pub Health. 2012; 5: 145-152
        • Blot S.
        • Vandewoude K.
        • Colardyn F.
        Nosocomial bacteremia involving Acinetobacter baumannii in critically ill patients: A matched cohort study.
        Intensive Care Med. 2003; 29: 471-475
        • Wisplinghoff H.
        • Perbix W.
        • Siefert H.
        Risk factors for nosocomial bloodstream infections due to Acinetobacter baumannii: A case-control study of adult burn patients.
        Clin Infect Dis. 1999; 28: 59-66
        • Horan T.C.
        • Andrus M.
        • Dudeck M.A.
        CDC/NHSN surveillance definition of health care-associated infection and criteria for specific types of infections in the acute care setting.
        Am J Infect Control. 2008; 36: 309-332
        • Abbo A.
        • Navon-Venezia S.
        • Hammer-Muntz O.
        • et al.
        Multidrug-resistant Acinetobacter baumannii.
        Emerg Infect Dis. 2005; 11: 22-29
        • Struelens M.J.
        Consensus guidelines for appropriate use and evaluation of microbial epidemiologic typing systems.
        Clin Microbiol Infect. 1996; 2: 2-11
        • Tenover F.C.
        • Arbeit R.D.
        • Goering R.V.
        • et al.
        Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: Criteria for bacterial strain typing.
        J Clin Microbiol. 1995; 33: 2233-2239
        • De Jong G.
        • Duse A.
        • Richards G.
        • et al.
        Back to basics—optimizing the use of available resources during an outbreak of multi-drug resistant Acinetobacter spp.
        J Hosp Infect. 2004; 57: 186-187
        • Nashef S.A.M.
        • Roques F.
        • Michel P.
        • et al.
        European system for cardiac operative risk evaluation (EuroSCORE).
        Eur J Cardiothorac Surg. 1999; 16: 9-13
        • Baran G.
        • Erbay A.
        • Bodur B.
        • et al.
        Risk factors for nosocomial imipenem-resistant Acinetobacter baumannii infections.
        Int J Infect Dis. 2008; 12: 16-21
        • Pierri M.D.
        • Capestro F.
        • Zingaro C.
        • et al.
        The changing face of cardiac surgery patients: An insight into a Mediterranean region.
        Eur J Cardiothorac Surg. 2010; 38: 407-413
        • Manikal V.M.
        • Landman D.
        • Saurina G.
        • et al.
        Endemic carbapenam-resistant Acinetobacter spp. in Brooklyn.
        New York: City-wide prevalence, interinstitutional spread, and relation to antibiotic usage. Clin Infect Dis. 2003; 31: 101-106
        • Allen S.
        Prevention and control of infection in the ICU.
        Curr Anaesth Crit Care. 2005; 16: 191-199
        • Pimentel J.D.
        • Lowb J.
        • Stylesb K.
        • et al.
        Control of an outbreak of multi-drug-resistant Acinetobacter baumannii in an intensive care unit and a surgical ward.
        J Hosp Infect. 2005; 59: 249-253
        • Zarrilli R.
        • Crispino M.
        • Bagattini M.
        • et al.
        Molecular epidemiology of sequential outbreaks of Acinetobacter baumannii in an Intensive Care Unit Shows the Emergence of Carbapenem Resistance.
        J Clin Microbiol. 2004; 42: 946-953
        • Michalopoulos A.
        • Geroulanos S.
        • Rosmarakis E.
        • et al.
        Frequency, characteristics, and predictors of microbiologically documented nosocomial infections after cardiac surgery.
        Eur J Cardiothorac Surg. 2006; 29: 456-460