Analysis and forecast for multidrug-resistant Acinetobacter baumannii Infections among liver transplant recipients

Acinetobacter baumannii (Ab) has become an important pathogenic bacterium with specific epidemic features in the intensive care unit. We explored the epidemiology of multidrug-resistant Ab infections among liver transplant recipients at the Liver Transplantation Center, 1st Affiliated Hospital of Shanghai Jiao Tong University.

Seventeen multidrug-resistant Ab strains were isolated from the sputum and bronchoalveolar lavage fluid specimens of 249 liver transplant recipients from January 2007 to December 2009. The drug resistance and minimum inhibitory concentration (MIC) for the 17 Ab strains were determined. The Ab strains were genotyped with the use of repetitive element-based polymerase chain reaction. The risk factors were also characterized by single-factor and multifactor analysis to the clinical data of the 249 liver transplant recipients.

The drug sensitivity results showed that the 17 Ab strains isolated displayed 100% drug resistance rate to aminoglycosides (gentamicin), quinolones (ciprofloxacin), penicillins (piperacillin), cephalosporins (ceftazidime, cefotaxime, and cefepime), and carbapenems (imipenem and meropenem). The 17 Ab strains could be divided into 3 genotypes: 1, 1, and 15 strains for types A, C, and B, respectively. Fungal culture positivity after operation (odds ratio [OR], 5.470) and tracheal intubation twice (OR, 11.538) were the independent risk factors for multidrug-resistant Ab strain infection.

Type B multidrug-resistant Ab strains are prevalent in the liver transplantation center, and they could be transmitted clonally. Liver transplant recipients with postoperational fungal culture positivity and tracheal intubation twice are prone to multidrug-resistant Ab infections. Therefore, a high degree of vigilance should be paid to those recipients to avoid nosocomial Ab infections.