scholarly journals Identification of Acinetobacter baumannii by Detection of the blaOXA-51-like Carbapenemase Gene Intrinsic to This Species

2006 ◽  
Vol 44 (8) ◽  
pp. 2974-2976 ◽  
Author(s):  
J. F. Turton ◽  
N. Woodford ◽  
J. Glover ◽  
S. Yarde ◽  
M. E. Kaufmann ◽  
...  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Gamal Wareth ◽  
Christian Brandt ◽  
Lisa D. Sprague ◽  
Heinrich Neubauer ◽  
Mathias W. Pletz

Abstract Background Acinetobacter baumannii ability to develop and acquire resistance makes it one of the most critical nosocomial pathogens globally. Whole-genome sequencing (WGS) was applied to identify the acquired or mutational variants of antimicrobial resistance (AMR) genes in 85 German A. baumannii strains utilizing Illumina technology. Additionally, the whole genome of 104 German isolates deposited in the NCBI database was investigated. Results In-silico analysis of WGS data revealed wide varieties of acquired AMR genes mediating resistance mostly to aminoglycosides, cephalosporins, carbapenems, sulfonamides, tetracyclines and macrolides. In the 189 analyzed genomes, the ant (3″)-IIa conferring resistance to aminoglycosides was the most frequent (55%), followed by blaADC.25 (38.6%) conferring resistance to cephalosporin, blaOXA-23 (29%) and the blaOXA-66 variant of the intrinsic blaOXA-51-likes (26.5%) conferring resistance to carbapenems, the sul2 (26%) conferring resistance to sulfonamides, the tet. B (19.5%) conferring resistance to tetracycline, and mph. E and msr. E (19%) conferring resistance to macrolides. blaTEM variants conferring resistance to cephalosporins were found in 12% of genomes. Thirteen variants of the intrinsic blaOXA-51 carbapenemase gene, blaOXA-510 and blaADC-25 genes were found in isolates obtained from dried milk samples. Conclusion The presence of strains harboring acquired AMR genes in dried milk raises safety concerns and highlights the need for changes in producing dried milk. Acquired resistance genes and chromosomal gene mutation are successful routes for disseminating AMR determinants among A. baumannii. Identification of chromosomal and plasmid-encoded AMR in the genome of A. baumannii may help understand the mechanism behind the genetic mobilization and spread of AMR genes.


2013 ◽  
Vol 18 (31) ◽  
Author(s):  
J W Decousser ◽  
C Jansen ◽  
P Nordmann ◽  
A Emirian ◽  
R A Bonnin ◽  
...  

We report the first outbreak of carbapenem-resistant NDM-1-producing Acinetobacter baumannii in Europe, in a French intensive-care unit in January to May 2013. The index patient was transferred from Algeria and led to the infection/colonisation of five additional patients. Concurrently, another imported case from Algeria was identified. The seven isolates were genetically indistinguishable, belonging to ST85. The blaNDM-1 carbapenemase gene was part of the chromosomally located composite transposon Tn125. This report underscores the growing concern about the spread of NDM-1-producing A. baumannii in Europe.


2008 ◽  
Vol 52 (11) ◽  
pp. 3837-3843 ◽  
Author(s):  
Jennifer M. Adams-Haduch ◽  
David L. Paterson ◽  
Hanna E. Sidjabat ◽  
Anthony W. Pasculle ◽  
Brian A. Potoski ◽  
...  

ABSTRACT A total of 49 unique clinical isolates of multidrug-resistant (MDR) Acinetobacter baumannii identified at a tertiary medical center in Pittsburgh, Pennsylvania, between August 2006 and September 2007 were studied for the genetic basis of their MDR phenotype. Approximately half of all A. baumannii clinical isolates identified during this period qualified as MDR, defined by nonsusceptibility to three or more of the antimicrobials routinely tested in the clinical microbiology laboratory. Among the MDR isolates, 18.4% were resistant to imipenem. The frequencies of resistance to amikacin and ciprofloxacin were high at 36.7% and 95.9%, respectively. None of the isolates was resistant to colistin or tigecycline. The presence of the carbapenemase gene bla OXA-23 and the 16S rRNA methylase gene armA predicted high-level resistance to imipenem and amikacin, respectively. bla OXA-23 was preceded by insertion sequence ISAba1, which likely provided a potent promoter activity for the expression of the carbapenemase gene. The structure of the transposon defined by ISAba1 differed from those reported in Europe, suggesting that ISAba1-mediated acquisition of bla OXA-23 may occur as an independent event. Typical substitutions in the quinolone resistance-determining regions of the gyrA and parC genes were observed in the ciprofloxacin-resistant isolates. Plasmid-mediated quinolone resistance genes, including the qnr genes, were not identified. Fifty-nine percent of the MDR isolates belonged to a single clonal group over the course of the study period, as demonstrated by pulsed-field gel electrophoresis.


2011 ◽  
Vol 55 (7) ◽  
pp. 3084-3090 ◽  
Author(s):  
Carlos Rumbo ◽  
Esteban Fernández-Moreira ◽  
María Merino ◽  
Margarita Poza ◽  
Jose Antonio Mendez ◽  
...  

ABSTRACTThe resistance ofAcinetobacter baumanniistrains to carbapenems is a worrying problem in hospital settings. The main mechanism of carbapenem resistance is the expression of β-lactamases (metalloenzymes or class D enzymes). The mechanisms of the dissemination of these genes amongA. baumanniistrains are not fully understood. In this study we used two carbapenem-resistant clinical strains ofA. baumannii(AbH12O-A2 and AbH12O-CU3) expressing the plasmid-borneblaOXA-24gene (plasmids pMMA2 and pMMCU3, respectively) to demonstrate thatA. baumanniireleases outer membrane vesicles (OMVs) duringin vitrogrowth. The use of hybridization studies enabled us to show that these OMVs harbored theblaOXA-24gene. The incubation of these OMVs with the carbapenem-susceptibleA. baumanniiATCC 17978 host strain yielded full resistance to carbapenems. The presence of the original plasmids harboring theblaOXA-24gene was detected in strain ATCC 17978 after the transformation of OMVs. New OMVs harboringblaOXA-24were released byA. baumanniiATCC 17978 after it was transformed with the original OMV-mediated plasmids, indicating the universality of the process. We present the first experimental evidence that clinical isolates ofA. baumanniimay release OMVs as a mechanism of horizontal gene transfer whereby carbapenem resistance genes are delivered to surroundingA. baumanniibacterial isolates.


2010 ◽  
Vol 54 (10) ◽  
pp. 4168-4177 ◽  
Author(s):  
Alessia Bertini ◽  
Laurent Poirel ◽  
Pauline D. Mugnier ◽  
Laura Villa ◽  
Patrice Nordmann ◽  
...  

ABSTRACT Acinetobacter baumannii is an opportunistic pathogen, especially in intensive care units, and multidrug-resistant isolates have increasingly been reported during the last decade. Despite recent progress in knowledge of antibiotic resistance mechanisms in A. baumannii, little is known about the genetic factors driving isolates toward multidrug resistance. In the present study, the A. baumannii plasmids were investigated through the analysis and classification of plasmid replication systems and the identification of A. baumannii-specific mobilization and addiction systems. Twenty-two replicons were identified by in silico analysis, and five other replicons were identified and cloned from previously uncharacterized A. baumannii resistance plasmids carrying the OXA-58 carbapenem-hydrolyzing oxacillinase. Replicons were classified into homology groups on the basis of their nucleotide homology. A novel PCR-based replicon typing scheme (the A. baumannii PCR-based replicon typing [AB-PBRT] method) was devised to categorize the A. baumannii plasmids into homogeneous groups on the basis of the nucleotide homology of their respective replicase genes. The AB-PBRT technique was applied to a collection of multidrug-resistant A. baumannii clinical isolates carrying the bla OXA-58 or bla OXA-23 carbapenemase gene. A putative complete conjugative apparatus was identified on one plasmid whose self-conjugative ability was demonstrated in vitro. We showed that this conjugative plasmid type was widely diffused in our collection, likely representing the most important vehicle promoting the horizontal transmission of A. baumannii resistance plasmids.


2009 ◽  
Vol 53 (6) ◽  
pp. 2657-2659 ◽  
Author(s):  
Samy Figueiredo ◽  
Laurent Poirel ◽  
Jacques Croize ◽  
Christine Recule ◽  
Patrice Nordmann

ABSTRACT Two clonally related Acinetobacter baumannii isolates, A1 and A2, were obtained from the same patient. Isolate A2, selected after an imipenem-containing treatment, showed reduced susceptibility to carbapenems. This resistance pattern was related to insertion of the ISAba1 element upstream of the naturally occurring bla OXA-66 carbapenemase gene as demonstrated by sequencing, reverse transcription-PCR analysis, and inactivation of the bla OXA-66 gene.


Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1340
Author(s):  
Jia Jie Woon ◽  
Cindy Shuan Ju Teh ◽  
Chun Wie Chong ◽  
Kartini Abdul Jabar ◽  
Sasheela Ponnampalavanar ◽  
...  

The emergence of carbapenem-resistant Acinetobacter baumannii (CRAB) has now become a global sentinel event. CRAB infections often instigate severe clinical complications and are potentially fatal, especially for debilitated patients. The present study aimed to conduct molecular characterization on CRAB isolated from patients in the intensive care unit from 2015 to 2016 and determine the risk factors associated with patients’ mortality. One hundred CRAB isolates were retrospectively selected and included in this study. Antimicrobial susceptibility testing showed that all isolates remained susceptible to colistin, even though 62% of them conferred resistance to all other classes of antibiotics tested. OXA carbapenemase gene was found to be the predominant carbapenemase gene, with 99% of the isolates coharbouring blaOXA-23-like and blaOXA-51-like carbapenemase genes. All isolates were carrying intact CarO genes, with the presence of various degree of nucleotide insertion, deletion and substitution. Overall, PFGE subtyped the isolates into 13 distinct pulsotypes, with the presence of 2 predominant pulsotypes. Univariate analysis implied that age, infection/colonization by CRAB, ethnicity, comorbidity and CRAB specimen source were significantly associated with in-hospital mortality. Multivariate analysis identified a higher risk of mortality for patients who are of Chinese ethnicity with diabetes as an underlying disease. As CRAB infection could lead to high rate of mortality, comprehensive infection control measures are needed to minimize the spread of this pathogen.


2019 ◽  
Vol 30 (2) ◽  
pp. 90-94
Author(s):  
Majid Eslami ◽  
Morvarid Shafiei ◽  
Seyede Amene Mirforughi ◽  
Ali Rajabi

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