In: Clinical Microbiology and Infection, 2015, vol. 21, no. 2, p. e9–e10
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In: Journal of Antimicrobial Chemotherapy, 2016, p. -
Objectives The origin of KPC is unknown. The aim of this study was to detect progenitors of KPC in silico and to functionally verify their β-lactam hydrolysis activity.Methods The sequence of KPC-2 was used to mine the NCBI protein sequence database. The best non-KPC hits were analysed by amino acid (aa) alignment and phylogenetic tree construction....
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In: Antimicrobial Agents and Chemotherapy, 2015, vol. 59, no. 5, p. 2780–2784
A multidrug-resistant Klebsiella pneumoniae isolate exhibiting heteroresistance to colistin was investigated. The colistin-resistant subpopulation harbored a single amino acid change (Asp191Tyr) in protein PhoP, which is part of the PhoPQ two-component system that activates pmrHFIJKLM expression responsible for l-aminoarabinose synthesis and polymyxin resistance. Complementation assays with a...
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In: Antimicrobial Agents and Chemotherapy, 2016, vol. 60, no. 5, p. 3199–3201
An extended-spectrum β-lactamase (ESBL)-producing and colistin-resistant Klebsiella pneumoniae clinical isolate was recovered from a patient who was treated with cefotaxime. This isolate harbored a blaCTX-M-15 ESBL gene that was associated with an ISEcp1 insertion sequence. Transposition of that tandem occurred within the chromosomal mgrB gene, leading...
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In: International Journal of Antimicrobial Agents, 2015, vol. 46, no. 1, p. 108–110
Gene modifications in the PmrAB and PhoPQ two-component regulatory systems, as well as inactivation of the mgrB gene, are known to be causes of colistin resistance in Klebsiella pneumoniae. The objective of this study was to characterise the mechanism involved in colistin resistance in a Klebsiella oxytoca isolate. A K. oxytoca clinical isolate showing resistance to colistin was recovered in...
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In: Antimicrobial Agents and Chemotherapy, 2017, vol. 61, no. 11, p. e01423-17
Mutations in crrAB genes encoding a two-component regulator involved in modifications of lipopolysaccharide were searched for among a collection of colistin- resistant Klebsiella pneumoniae isolates. Four isolates, respectively, producing carbapenemases NDM-1, OXA-181, or KPC-2 showed mutated CrrB proteins compared with those in wild-type strains. Complementation assays with a wild-type CrrB...
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In: Clinical Microbiology and Infection, 2017, p. -
Objectives: Because of the emergence of plasmid-mediated (mcr-1 and mcr-2 genes) and chromosomally encoded colistin resistance, reliable methods for detecting colistin resistance/susceptibility in routine laboratories are required. We evaluated the respective performances of the BD Phoenix automated system, the newly developed Rapid Polymyxin NP test and the broth microdilution (BMD) reference...
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In: International Journal of Antimicrobial Agents, 2017, vol. 50, no. 3, p. 503–504
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In: Eurosurveillance, 2016, vol. 21, no. 37, p. -
From January 2014 to December 2014, 972 consecutive non-replicate carbapenemase-producing Enterobacteriaceae isolates from colonised or infected patients were collected at the Associated French National Reference Centre as part of the French national survey on antimicrobial resistance. It included 577 Klebsiella spp. (59%), 236 Escherichia coli (24%), 108 Enterobacter spp. (11%), 50...
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In: Antimicrobial Agents and Chemotherapy, 2014, vol. 58, no. 8, p. 4762–4766
A series of colistin-resistant Klebsiella pneumoniae isolates recovered from different countries was investigated in order to evaluate the involvement of the PmrA/PmrB two-component system in this resistance. Six isolates possessed a mutated PmrB protein, which is encoded by the pmrB gene, part of the pmrCAB operon involved in lipopolysaccharide modification. The same amino acid substitution...
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