Rapid spread of multiresistant Acinetobacter baumannii isolates in intensive care units (ICUs) and in vitro activity of colistin and tigecycline.


A cinetobacter baumannii is a pleomorphic aerobic gram-negative bacillus, which is widespread in nature and frequently isolated from the hospital environment and hospitalized patients. The organism is particularly common in patients who are intubated and in those who carry multiple intravenous lines or monitoring devices, surgical drains, or indwelling urinary catheters, and usually causes a large number of clinical conditions, including pneumonia, bacteraemia, urinary tract infections, wound infections, endocarditis and meningitis. A. baumannii is susceptible to relatively few antibiotics including meropenem, colistin, amikacin, rifampicin, minocycline and tigecycline [1]. Multidrug-resistant A. baumannii is not a new or emerging phenomenon, as it is inherently resistant to multiple antibiotics. Therefore, the treatment of severe A. baumannii infections is often difficult [2, 3]. In recent years A. baumannii has emerged as an important nosocomial pathogen, particularly in intensive care units (ICUs) where several outbreaks have been described. More recently, microbiological surveillance data showed an increased prevalence of up to 4% of A. baumannii isolates in ICUs of Italian hospitals [4-7]. In 2011 a significant increase in A. baumannii isolates (Vitek II system, bioMérieux, Marcy l’Etoile, France) was observed in the ICU of the SS Annunziata Hospital of Taranto in southern Italy. In the same year, 81 strains were isolated, compared to 11 and 10 isolates in 2009 and 2010. Therefore, at present A. baumannii is the prevalent strain among the bacterial isolates in our ICU with an incidence rate of 15% (2.7% in 2009 and 1.9% in 2010) versus Pseudomonas aeruginosa (11.8%) and Klebsiella pneumoniae (11.3%). In most cases (79%), A. baumannii was isolated from the respiratory tract and in 12.3% from the bloodstream, while in the remaining cases from liquor and cutaneous wounds. Our data show that the most common phenotype (99% of the isolates) was resistant to piperacillin, piperacillin/tazobactam, cefepime, ceftazidime, aztreonam, ciprofloxacin, levofloxacin, minocycline and imipenem. Resistance to gentamicin and isepamicin was observed in 3.7% and 10.3% of the isolates. No resistance to colistin or tigecycline was observed in any A. baumannii strain isolates. In vitro activity of antimicrobial agents against A. Lettera all’Editore

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@article{Buccoliero2012RapidSO, title={Rapid spread of multiresistant Acinetobacter baumannii isolates in intensive care units (ICUs) and in vitro activity of colistin and tigecycline.}, author={Giovanni Buccoliero and Elisabetta Morelli and Gaetano Lonero and Chiara Romanelli and Francesco Resta and Salvatore Pisconti}, journal={Le infezioni in medicina : rivista periodica di eziologia, epidemiologia, diagnostica, clinica e terapia delle patologie infettive}, year={2012}, volume={20 4}, pages={296-8} }