OXA-51-like β-lactamases and their association with particular epidemic lineages of Acinetobacter baumannii

Abstract

Sixty diverse clinical Acinetobacter baumannii isolates of worldwide origin were assigned to sequence groups, based on a multiplex PCR for the ompA, csuE and bla(OXA-51-like) genes. The majority (77%) of isolates belonged to sequence groups 1 and 2 (SG1 and SG2), with sequence group 3 (SG3) and non-grouped isolates accounting for the remainder. The isolates were not closely related according to pulsed-field gel electrophoresis (PFGE), and the majority were sensitive to imipenem and meropenem. The construction of a linkage map of OXA-51-like beta-lactamase sequence relationships revealed two closely related clusters of enzymes, one focused around OXA-66 and the other around OXA-69. Isolates belonging to SG1 encoded an enzyme from the OXA-66 cluster, while those belonging to SG2 encoded an enzyme from the OXA-69 cluster. All SG3 isolates encoded OXA-71, which does not form part of a close enzyme grouping. Major multinational lineages accounted for a significant proportion of A. baumannii clinical isolates, and the evolution of the OXA-51-like enzymes appears to be an ongoing process.

Characterization of Epidemiologically Unrelated Acinetobacter baumannii Isolates from Four Continents by Use of Multilocus Sequence Typing, Pulsed-Field Gel Electrophoresis, and Sequence-Based Typing of bla OXA-51-like Genes

“…Forty-four isolates of A. baumannii from 22 countries, including three standard representatives of the endemic pan-European clonal lineages I, II, and III, were included in this study. All isolates were identified as A. baumannii as described previously (8) and by the presence of a bla OXA-51-like gene (45). All the isolates were recovered from cases of invasive disease in various hospitals between 1982 and 2006.…”

Occurrence of OXA-107 and IS Aba 1 in Carbapenem-Resistant Isolates of Acinetobacter baumannii from Croatia

“…The first description of carbapenem-resistant clinical isolates of A. baumannii in Croatia reported the presence of an OXA-69-like oxacillinase (4). The unusual OXA-107 enzyme was first detected in A. baumannii isolates from Poland and Slovenia (3) and is closely related to OXA-69, with an amino acid change at position 167 that replaces leucine with valine (3). OXA-107 is not distinguished from OXA-69 by the multiplex PCR method of Turton et al (8).…”

Pneumonia caused by extensive drug-resistant Acinetobacter baumannii among hospitalized patients: genetic relationships, risk factors and mortality

“…Recently, sequencebased typing (SBT) of bla OXA-51-like gene variants was reported to have potential for use in the epidemiological characterization of A. baumannii isolates obtained from various locations in Europe. bla OXA-69 , bla OXA-66 , and bla OXA-71 are the predominant members of closely related bla OXA-51-like subgroups, which are associated with European clone I (EUI), EUII, and EUIII, respectively [14][15][16]. However, few studies have investigated the correlation between bla OXA-51-like variants with MLST typing.…”

“…Although MLST has many advantages, it is a robust scheme that is often time-consuming, expensive, and labour-intensive [14]. Currently, several studies have reported that sequence-based typing (SBT) of bla OXA-51-like gene variants has potential for application to assess the epidemiological characterization of A. baumannii [14][15][16], but more data are needed.…”