OBJECTIVES: The aac(6')-Ih gene encoding aminoglycoside 6'-N-acetyltransferase type I subtype h [AAC(6')-Ih] is plasmid-borne in Acinetobacter baumannii where it confers high-level amikacin resistance, but its origin remains unknown. We searched for the gene in the genomes of a collection of 133 Acinetobacter spp. and studied its species specificity, expression and dissemination. METHODS: Gene copy number was determined by quantitative PCR, expression by quantitative RT-PCR, MIC by microdilution and transfer by plasmid mobilization. RESULTS: The aac(6')-Ih gene was present in the chromosome of the two Acinetobacter gyllenbergii of the collection and was detected in all seven A. gyllenbergii clinical isolates. They had indistinguishable flanking regions indicating that the gene was intrinsic to this species. A. baumannii PIS Aba23 promoters were provided by insertion of ISAba23, which disrupted the Pnative promoter in A. gyllenbergii. Both types of promoters were similarly potent in Escherichia coli and A. baumannii. Aminoglycoside MICs for A. baumannii harbouring pIP1858 were higher than for A. gyllenbergii due to gene dosage. The non-self-transferable plasmid could be mobilized to other A. baumannii cells by the broad host range plasmid RP4. CONCLUSIONS: We have found the origin of aac(6')-Ih in A. gyllenbergii, a species isolated, although rarely, in humans, and documented that dissemination of this gene is restricted to the Acinetobacter genus.
- MeSH
- acetyltransferasy genetika metabolismus MeSH
- Acinetobacter baumannii klasifikace účinky léků enzymologie genetika MeSH
- aminoglykosidy metabolismus farmakologie MeSH
- antibakteriální látky metabolismus farmakologie MeSH
- bakteriální léková rezistence * MeSH
- genová dávka MeSH
- infekce bakteriemi rodu Acinetobacter mikrobiologie MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- plazmidy analýza MeSH
- přenos genů horizontální MeSH
- promotorové oblasti (genetika) MeSH
- transpozibilní elementy DNA MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Od června 2015 do května 2016 byly v sedmi nemocnicích České republiky zachyceny extenzivně rezistentní kmeny Acinetobacter baumannii náležející k celosvětově rozšířenému epidemickému klonu II. Tyto kmeny nesly geny pro karbapenemázu OXA-23 a metylázu ArmA a byly rezistentní ke všem ß-laktamům a aminoglykosidům.Tento rezistotyp je v České republice nový a jeho šíření může dále omezit léčebné možnosti u acinetobakterových infekcí.
Extensively drug-resistant strains of Acinetobacter baumannii belonging to worldwide epidemic clone II were isolated in seven Czech hospitals between June 2015 and April 2016. These strains carried the genes encoding the OXA-23 carbapenemase and ArmA methylase and were resistant to all ß-lactams and aminoglycosides. Thisresistotype is new in the Czech Republic and its dissemination may further complicate the therapy of Acinetobacter infections.
- MeSH
- Acinetobacter baumannii * enzymologie genetika účinky léků MeSH
- aminoglykosidy farmakologie terapeutické užití MeSH
- beta-laktamasy škodlivé účinky MeSH
- beta-laktamová rezistence genetika MeSH
- infekce spojené se zdravotní péčí enzymologie mikrobiologie prevence a kontrola MeSH
- karbapenemy farmakologie terapeutické užití MeSH
- lidé MeSH
- mnohočetná bakteriální léková rezistence * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been recently introduced to many diagnostic microbiological laboratories. Besides the identification of bacteria and fungi, that technique provides a potentially useful tool for the detection of antimicrobial resistance, especially of that conferred by β-lactamases. Here, we describe an assay allowing a detection of meropenem hydrolysis in clinical isolates of Enterobacteriaceae, Pseudomonas spp., and Acinetobacter baumannii using MALDI-TOF MS. This method is able to confirm carbapenemases within 3 h. The results are important for proper and fast intervention to limit the spread of carbapenemase-producing bacteria and provide information for appropriate initial therapy of the infections caused by these microbes.
- MeSH
- Acinetobacter baumannii účinky léků enzymologie genetika izolace a purifikace MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální proteiny genetika metabolismus MeSH
- beta-laktamasy genetika metabolismus MeSH
- beta-laktamová rezistence genetika MeSH
- biotest * MeSH
- exprese genu MeSH
- hydrolýza MeSH
- infekce bakteriemi rodu Acinetobacter diagnóza farmakoterapie mikrobiologie MeSH
- lidé MeSH
- pseudomonádové infekce diagnóza farmakoterapie mikrobiologie MeSH
- Pseudomonas účinky léků enzymologie genetika izolace a purifikace MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- thienamyciny farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
OBJECTIVES: Sulbactam is well known to have clinically relevant intrinsic activity against Acinetobacter baumannii. Although secondary resistance to this drug has long been reported in acinetobacters, virtually nothing is known about its molecular basis. The aim of this study was to test the hypothesis that β-lactamase TEM-1 is responsible for sulbactam resistance in A. baumannii. METHODS: Seventeen clinical strains of A. baumannii were selected to represent different combinations of quantitative susceptibilities to sulbactam and molecular typing characteristics. The strains were screened by PCR for the presence of the blaTEM-1 gene and its variants. Amplicons encompassing the blaTEM genes, including their promoters, were sequenced. The expression and copy number of the blaTEM genes were assessed using semi-quantitative real-time PCR. Transfer of the blaTEM-1 gene into a susceptible A. baumannii strain was achieved by electroporation. RESULTS: Six strains were negative for the blaTEM gene and had sulbactam MICs of 0.5-1.0 mg/L, 10 strains harboured blaTEM-1 and showed MICs ≥ 8.0 mg/L, except for one strain with an MIC of 2 mg/L, while the remaining strain carried blaTEM-19 and had an MIC of 1 mg/L. The level of blaTEM-1 expression positively correlated with the MICs of sulbactam (r = 0.92). Promoter P4 was linked to the blaTEM gene in all strains except for a P3-carrying strain (an MIC of 2 mg/L). Transformation of the susceptible A. baumannii strain with blaTEM-1 resulted in a 64-fold increase in sulbactam MIC and in resistance to ticarcillin and piperacillin, but no change in susceptibility to broad-spectrum generation cephalosporins, aztreonam or carbapenems. CONCLUSIONS: The results presented suggest that TEM-1 represents a clinically relevant mechanism of sulbactam resistance in A. baumannii.
- MeSH
- Acinetobacter baumannii účinky léků enzymologie izolace a purifikace MeSH
- bakteriální léková rezistence * MeSH
- beta-laktamasy genetika sekrece MeSH
- DNA bakterií genetika MeSH
- genová dávka MeSH
- infekce bakteriemi rodu Acinetobacter mikrobiologie MeSH
- inhibitory beta-laktamasy MeSH
- inhibitory enzymů farmakologie MeSH
- lidé MeSH
- polymerázová řetězová reakce MeSH
- sekvenční analýza DNA MeSH
- stanovení celkové genové exprese MeSH
- sulbaktam farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- Acinetobacter baumannii enzymologie genetika izolace a purifikace MeSH
- beta-laktamasy genetika MeSH
- genotyp MeSH
- infekce bakteriemi rodu Acinetobacter mikrobiologie MeSH
- lidé MeSH
- mnohočetná bakteriální léková rezistence * MeSH
- molekulární typizace MeSH
- multilokusová sekvenční typizace MeSH
- polymerázová řetězová reakce MeSH
- prospektivní studie MeSH
- sekvenční analýza DNA MeSH
- senioři MeSH
- transpozibilní elementy DNA MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- Publikační typ
- dopisy MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is a potentially useful tool for the detection of antimicrobial resistance, especially that conferred by β-lactamases. Here we describe a modification of a previously reported MALDI-TOF MS meropenem hydrolysis assay. The modified method was validated on 108 carbapenemase-producing members of the Enterobacteriaceae, two NDM-1-producing Acinetobacter baumannii isolates, and 35 carbapenem-resistant enterobacteria producing no carbapenemase. The detection of carbapenemases by MALDI-TOF MS seems to be a powerful, quick, and cost-effective method for microbiological laboratories.
- MeSH
- Acinetobacter baumannii enzymologie MeSH
- bakteriální proteiny metabolismus MeSH
- beta-laktamasy metabolismus MeSH
- Enterobacteriaceae enzymologie MeSH
- enterobakteriální infekce mikrobiologie MeSH
- hydrolýza MeSH
- lidé MeSH
- mikrobiální testy citlivosti metody MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice metody MeSH
- thienamyciny metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- validační studie MeSH
We describe the isolation of an NDM-1-producing Acinetobacter baumannii in a Czech patient repatriated in July 2011 from Egypt. The infection spread to another patient on the same ward. Both isolates showed the same resistance pattern and were susceptible only to colistin. They had an identical PFGE pattern and belonged to the same sequence type ST 1. Sequencing of the blaNDM gene identified the NDM-1 variant of the carbapenemase, surrounded by two copies of insertion sequence ISAba125.
- MeSH
- Acinetobacter baumannii enzymologie genetika izolace a purifikace MeSH
- amplifikace genu MeSH
- antibakteriální látky terapeutické užití MeSH
- bakteriální proteiny biosyntéza MeSH
- beta-laktamasy biosyntéza genetika MeSH
- beta-laktamová rezistence MeSH
- cestování MeSH
- infekce bakteriemi rodu Acinetobacter diagnóza farmakoterapie přenos MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- molekulární sekvence - údaje MeSH
- polymerázová řetězová reakce MeSH
- pulzní gelová elektroforéza MeSH
- techniky typizace bakterií MeSH
- ventilátorová pneumonie mikrobiologie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
- Egypt MeSH
