Detection of intrinsic blaOXA-51-like by multiplex PCR on its own is not reliable for the identification of Acinetobacter baumannii

Zander, Esther; Higgins, Paul G.; Fernández-González, Ana; Seifert, Harald

doi:10.1016/j.ijmm.2012.12.007

Cited by 35 publications

(30 citation statements)

References 13 publications

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“…The strains were identified by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (24) and amplified rRNA gene restriction analysis (ARDRA) (25). Species identification was confirmed by detection of the OXA-51 gene by PCR (26) and also by detection of the bsp gene (a novel target) by real-time quantitative PCR (27,28).…”

Section: Methodsmentioning

confidence: 94%

Contribution of Efflux Pumps, Porins, and β-Lactamases to Multidrug Resistance in Clinical Isolates of Acinetobacter baumannii

Rumbo

Gato

López

et al. 2013

Antimicrob Agents Chemother

166

142

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eWe investigated the mechanisms of resistance to carbapenems, aminoglycosides, glycylcyclines, tetracyclines, and quinolones in 90 multiresistant clinical strains of Acinetobacter baumannii isolated from two genetically unrelated A. baumannii clones: clone PFGE-ROC-1 (53 strains producing the OXA-58 ␤-lactamase enzyme and 18 strains with the OXA-24 ␤-lactamase) and clone PFGE-HUI-1 (19 strains susceptible to carbapenems). We used real-time reverse transcriptase PCR to correlate antimicrobial resistance (MICs) with expression of genes encoding chromosomal ␤-lactamases (AmpC and OXA-51), porins (OmpA, CarO, Omp33, Dcap-like, OprB, Omp25, OprC, OprD, and OmpW), and proteins integral to six efflux systems (AdeABC, AdeIJK, AdeFGH, CraA, AbeM, and AmvA). Overexpression of the AdeABC system (level of expression relative to that by A. baumannii ATCC 17978, 30-to 45-fold) was significantly associated with resistance to tigecycline, minocycline, and gentamicin and other biological functions. However, hyperexpression of the AdeIJK efflux pump (level of expression relative to that by A. baumannii ATCC 17978, 8-to 10-fold) was significantly associated only with resistance to tigecycline and minocycline (to which the TetB efflux system also contributed). TetB and TetA(39) efflux pumps were detected in clinical strains and were associated with resistance to tetracyclines and doxycycline. The absence of the AdeABC system and the lack of expression of other mechanisms suggest that tigecycline-resistant strains of the PFGE-HUI-1 clone may be associated with a novel resistance-nodulation-cell efflux pump (decreased MICs in the presence of the inhibitor Phe-Arg ␤-naphthylamide dihydrochloride) and the TetA(39) system.

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Section: Methodsmentioning

confidence: 94%

Contribution of Efflux Pumps, Porins, and β-Lactamases to Multidrug Resistance in Clinical Isolates of Acinetobacter baumannii

Rumbo

Gato

López

et al. 2013

Antimicrob Agents Chemother

166

142

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“…In addition to providing promoters to increase the expression of bla OXA genes, some insertion sequences have been found to insert into the middle of bla OXA genes, disrupting their function. The insertion sequences ISAba15 and ISAba19 have been identified to be inserted into bla OXA-66 and bla OXA-78 , respectively (95). To date, this has been detected very rarely, suggesting that in most instances, it is more beneficial for the bacteria to carry a gene coding for a functional OXA-51-like enzyme.…”

Section: Other Insertion Sequences In Acinetobactermentioning

confidence: 99%

OXA β-Lactamases

2014

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SUMMARY The OXA β-lactamases were among the earliest β-lactamases detected; however, these molecular class D β-lactamases were originally relatively rare and always plasmid mediated. They had a substrate profile limited to the penicillins, but some became able to confer resistance to cephalosporins. From the 1980s onwards, isolates of Acinetobacter baumannii that were resistant to the carbapenems emerged, manifested by plasmid-encoded β-lactamases (OXA-23, OXA-40, and OXA-58) categorized as OXA enzymes because of their sequence similarity to earlier OXA β-lactamases. It was soon found that every A. baumannii strain possessed a chromosomally encoded OXA β-lactamase (OXA-51-like), some of which could confer resistance to carbapenems when the genetic environment around the gene promoted its expression. Similarly, Acinetobacter species closely related to A. baumannii also possessed their own chromosomally encoded OXA β-lactamases; some could be transferred to A. baumannii , and they formed the basis of transferable carbapenem resistance in this species. In some cases, the carbapenem-resistant OXA β-lactamases (OXA-48) have migrated into the Enterobacteriaceae and are becoming a significant cause of carbapenem resistance. The emergence of OXA enzymes that can confer resistance to carbapenems, particularly in A. baumannii , has transformed these β-lactamases from a minor hindrance into a major problem set to demote the clinical efficacy of the carbapenems.

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“…To resolve discrepancies resulting from iii above, select primers were used for more accurate species identification (18)(19)(20)(21). Statistical methods.…”

Section: Methodsmentioning

confidence: 99%

Informing Antibiotic Treatment Decisions: Evaluating Rapid Molecular Diagnostics To Identify Susceptibility and Resistance to Carbapenems against Acinetobacter spp. in PRIMERS III

et al. 2017

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The widespread dissemination of carbapenem-resistant Acinetobacter spp. has created significant therapeutic challenges. At present, rapid molecular diagnostics (RMDs) that can identify this phenotype are not commercially available. Two RMD platforms, PCR combined with electrospray ionization mass spectrometry (PCR/ ESI-MS) and molecular beacons (MB), for detecting genes conferring resistance/susceptibility to carbapenems in Acinetobacter spp. were evaluated. An archived collection of 200 clinical Acinetobacter sp. isolates was tested. Predictive values for susceptibility and resistance were estimated as a function of susceptibility prevalence and were based on the absence or presence of beta-lactamase (bla) NDM, VIM, IMP, KPC, and OXA carbapenemase genes (e.g., bla , bla , and bla OXA-58 found in this study) against the reference standard of MIC determinations. According to the interpretation of MICs, 49% (n ϭ 98) of the isolates were carbapenem resistant (as defined by either resistance or intermediate resistance to imipenem). The susceptibility sensitivities (95% confidence interval [CI]) for imipenem were 82% (74%, 89%) and 92% (85%, 97%) for PCR/ESI-MS and MB, respectively. Resistance sensitivities (95% CI) for imipenem were 95% (88%, 98%) and 88% (80%, 94%) for PCR/ESI-MS and MB, respectively. PRIMERS III establishes that RMDs can discriminate between carbapenem resistance and susceptibility in Acinetobacter spp. In the context of a known prevalence of resistance, SPVs and RPVs can inform clinicians regarding the best choice for empiric antimicrobial therapy against this multidrug-resistant pathogen.

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Detection of intrinsic blaOXA-51-like by multiplex PCR on its own is not reliable for the identification of Acinetobacter baumannii

Cited by 35 publications

References 13 publications

Contribution of Efflux Pumps, Porins, and β-Lactamases to Multidrug Resistance in Clinical Isolates of Acinetobacter baumannii

Contribution of Efflux Pumps, Porins, and β-Lactamases to Multidrug Resistance in Clinical Isolates of Acinetobacter baumannii

OXA β-Lactamases

Informing Antibiotic Treatment Decisions: Evaluating Rapid Molecular Diagnostics To Identify Susceptibility and Resistance to Carbapenems against Acinetobacter spp. in PRIMERS III

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