Infection with Acinetobacter baumannii in an intensive care unit in the Western part of Romania

Abstract

Background: Acinetobacter baumannii is one of the main causes of morbidity and mortality in critical condition patients. The pathogen's ability to survive under a wide range of environment conditions and to persist for long periods of time on areas represents a frequent cause of endemic infection hotbeds especially in the Intensive Care Unit. The objectives of the study are: determining the 5-year incidence of A. baumannii infection in patients admitted in the ICU which needed mechanical ventilation; the analysis of these cases regarding pathological antecedents; processing the data regarding these cases; gradual analysis of the susceptibility/resistance of isolated A. baumannii strains; observing the emergence of A. baumannii infection in patients transferred into the ICU.

Methods: We have performed an observational retrospective study regarding the incidence of Acinetobacter baumannii infections in the Intensive Care Unit of the Hospital of Infectious Diseases and Pneumophtisiology "Victor Babes" Timisoara, Clinic II Infectious Diseases, during June 2011 - June 2015.

Results: We have identified a high prevalence of Acinetobacter baumannii infection, with an average period of 6 days. Bronchial suction was the most common pathological product in the study (90 % of the cases). Resistance to antimicrobials has been determined: the lowest resistance was recorded for ampicillin + sulbactam (81.1 %), and the highest resistance rate was recorded for ceftazidime and imipenem (94.6 % each). When comparing resistance to third generation cephalosporins, the difference was not statistically significant (94.6 % for ceftazidime vs. 86.5 % for cefoperazone, p = 0.117). Within the present study we were able to observe a significantly high resistance of the germ to carbapenems, with a good sensitivity to aminoglycosides, and to colistin. Only one strain of Acinetobacter baumannii was resistant to all classes of tested antibiotics.

Conclusions: Generally, carbapenems represented the elective treatment in severe infections; however, the number of carbapenem-resistant Acinetobacter baumannii strains is growing, dramatically reducing therapeutic options, fact that brings back to our attention reusing colistin, although the administration of this antibiotic has been limited due to new antibiotics classes.

Keywords: Acinetobacter baumannii; Antibiotic resistance; Infection; Intensive Care Unit; Mechanical ventilation.

Fig. 1

Clinical samples used for the isolation of Acinetobacter baumannii strains included in the study

Fig. 2

Beta-lactam resistance of bacterial strains included in the study

Fig. 3

Aminoglycosides and colistin resistance of bacterial strains included in the study

Fig. 4

Yearly susceptibility to colistin of bacterial strains included in the study