Temporal evolution of carbapenem-resistant Acinetobacter baumannii in Curitiba, southern Brazil.

In the last few years, carbapenem-resistant Acinetobacter baumannii isolates (CR-AB) have been identified worldwide. The first description of OXA-23-producing A baumannii in Brazil was from the city of Curitiba in 2003. The aim of the present study was to evaluate the persistence and dissemination of the first OXA-23-producing A baumannii clone isolated from patients in Hospital de Clinicas, Curitiba, Brazil. An antimicrobial susceptibility profile of the isolates was determined by the standard agar dilution method. Molecular detection of beta-lactamase genes was done by polymerase chain reaction. The clonal relationship of the isolates was analyzed by pulsed-field gel electrophoresis (PFGE). Epidemiologic and clinical features were evaluated as well. Genotypic analysis of 172 CR-AB isolates by PFGE identified 3 distinct major PFGE clusters (A, B, and C, accounting for 36, 69, and 65 isolates, respectively). All isolates carried the bla(OXA-23)-like gene and were multidrug-resistant, but were susceptible to tigecycline and polymixin B. The mortality rate related to CR-AB infection was 45.4%, and ventilator-associated pneumonia and bloodstream infections were the most frequent clinical manifestations. The presence of 3 clones among the CR-AB isolates suggests that cross-transmission was the main mechanism responsible for dissemination of OXA-23 producers. PFGE pattern A was genotypically similar to that of the first OXA-23-producing A baumannii clone identified in Curitiba in 1999. This clone persisted in the same hospital until April 2004. The presence of the bla(OXA-)23-like gene was the main mechanism associated with carbapenem resistance among the isolates studied.

Schimith Bier KE ，Luiz SO ，Scheffer MC ，Gales AC ，Paganini MC ，Nascimento AJ ，Carignano E ，Dalla Costa LM ... -  《-》

Emergence of carbapenem resistance in Acinetobacter baumannii in the Czech Republic is associated with the spread of multidrug-resistant strains of European clone II.

Nemec A ，Krízová L ，Maixnerová M ，Diancourt L ，van der Reijden TJ ，Brisse S ，van den Broek P ，Dijkshoorn L ... -  《-》

Identification of multidrug- and carbapenem-resistant Acinetobacter baumannii in Canada: results from CANWARD 2007.

McCracken M ，DeCorby M ，Fuller J ，Loo V ，Hoban DJ ，Zhanel GG ，Mulvey MR ... -  《-》

Epidemiological characterization and distribution of carbapenem-resistant Acinetobacter baumannii clinical isolates in Italy.

This study was aimed at tracing the molecular characteristics of carbapenem-resistant Acinetobacter baumannii (CRAB) clinical isolates in Italy with both pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Two hundred and two CRAB isolates were collected during 2004-2009, in two different surveillance periods, from 22 Italian hospitals that were representative for both distribution and infection. PFGE was performed, and the MLST scheme used was based on the gene sequence as published on the MLST Pasteur website http://www.pasteur.fr/mlst. Representatives of the major European clones I (RUH 875) and II (RUH 134) were used as controls. The two groups of isolates were characterized for their carbapenem resistance genes: 154 of 202 carried bla(OXA-58) alone, 21 of 202 also carried bla(OXA-23) , and 27 of 202 carried bla(OXA-23) alone. No isolates were positive for bla(OXA-24) . Genotype analysis of all isolates identified four distinct patterns by PFGE, which correlated with four distinct sequence types (STs) by MLST. The distribution of these four clusters in Italy confirmed the propensity of A. baumannii for nosocomial cross-transmission in a vast geographical area. We observed that clones A and B had similarities with European clone II and I respectively. By MLST, clone A was ST2, like European clone II, and clone B was ST1, like European clone I. PFGE and MLST showed the same discriminatory power and reproducibility. In addition, the two methods were concordant in defining CRAB Italian clones and in correlating them with the two pan-European clones.

Mezzatesta ML ，D'Andrea MM ，Migliavacca R ，Giani T ，Gona F ，Nucleo E ，Fugazza G ，Pagani L ，Rossolini GM ，Stefani S ... -  《-》

Two distinct clones of carbapenem-resistant Acinetobacter baumannii isolates from Korean hospitals.

Park YK ，Choi JY ，Jung SI ，Park KH ，Lee H ，Jung DS ，Heo ST ，Kim SW ，Chang HH ，Cheong HS ，Chung DR ，Peck KR ，Song JH ，Ko KS ... -  《-》