Description of the metallo-beta-lactamase GIM-1 in Acinetobacter pittii

作者:Kaase Martin*; Szabados Florian; Pfennigwerth Niels; Anders Agnes; Geis Gabriele; Pranada Arthur B; Roessler Susann; Lang Uwe; Gatermann Soeren G
来源:Journal of Antimicrobial Chemotherapy, 2014, 69(1): 81-84.
DOI:10.1093/jac/dkt325

摘要

Objectives: To characterize the mechanisms involved in the reduced carbapenem susceptibility of five Acinetobacter pittii strains isolated from different regions of Germany. Methods: The strains were analysed by susceptibility testing, phenotypic tests for metallo-beta-lactamase production, sequencing of the integron structure and strain typing by PFGE, as well as multilocus sequence typing (MLST) and plasmid analysis by S1 restriction and hybridization. Results: Despite GIM-1 production, the MICs of imipenem were only 4 mg/L for four strains and some methods of phenotypic MBL detection failed. According to PFGE and MLST, the strains belonged to four different clones, but bla(GIM-1) was present in identical integron structures in all strains and carried on plasmids of similar to 60 kb. Conclusions: For the first time, GIM-1 has been demonstrated in A. pittii. This resistance mechanism has previously been reported only in Enterobacteriaceae and Pseudomonas aeruginosa. As GIM-1 was found in strains with diverse clonal backgrounds, but encoded on plasmids of a similar size, further spread among Acinetobacter spp. seems possible. The detection of GIM-1 production might be challenging in some strains due to the low MICs of carbapenems.