Identification of 50 Class D β-Lactamases and 65 Acinetobacter-Derived Cephalosporinases in Acinetobacter spp

• DOI: 10.1128/aac.01261-13
• Publication Date: 2013-11-26T03:28:07Z
• Authors: Bruno Périchon; Sylvie Goussard; Violaine Walewski; Lenka Krizova; Gustavo Cerqueira; Cheryl Murphy; Michael Feldgarden; Jennifer Wortman; Dominique Clermont; Alexandr Nemec; Patrice Courvalin
• Keywords: Acinetobacter baumannii; Acinetobacter calcoaceticus; rpoB; Horizontal Gene Transfer; Insertion sequence

Whole-genome sequencing of a collection 103 Acinetobacter strains belonging to 22 validly named species and another 16 putative allowed detection genes for 50 new class D β-lactamases 65 Acinetobacter-derived cephalosporinases (ADC). All oxacillinases (OXA) contained the three typical motifs β-lactamases, STFK, (F/Y)GN, K(S/T)G. The phylogenetic tree drawn from OXA sequences led an increase in number groups 7 18. topologies RpoB trees were similar, supporting ancient acquisition blaOXA by species. β-lactamase appeared be intrinsic several species, such as baumannii, pittii, calcoaceticus, lwoffii. Neither blaOXA-40/143- nor blaOXA-58-like detected, their origin remains therefore unknown. analysis based on alignment deduced blaADC revealed five main clusters, one containing ADC closely related A. baumannii others composed remaining No indication or transfer was observed between distantly except blaOXA-279, possibly transferred genomic 6 parvus. Analysis β-lactam susceptibility seven harboring cloning corresponding Escherichia coli susceptible strain indicated very weak hydrolysis carbapenems. Overall, this study reveals large pool different spp., potentially transferable pathogenic genus.