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Vancomycin-resistant vanB-type Enterococcus faecium isolates expressing varying levels of vancomycin resistance and being highly prevalent among neonatal patients in a single ICU

BACKGROUND: Vancomycin-resistant isolates of E. faecalis and E. faecium are of special concern and patients at risk of acquiring a VRE colonization/infection include also intensively-cared neonates. We describe here an ongoing high prevalence of VanB type E. faecium in a neonatal ICU hardly to ident...

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Autores principales: Werner, Guido, Klare, Ingo, Fleige, Carola, Geringer, Uta, Witte, Wolfgang, Just, Heinz-Michael, Ziegler, Renate
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3533821/
https://www.ncbi.nlm.nih.gov/pubmed/22958440
http://dx.doi.org/10.1186/2047-2994-1-21
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author Werner, Guido
Klare, Ingo
Fleige, Carola
Geringer, Uta
Witte, Wolfgang
Just, Heinz-Michael
Ziegler, Renate
author_facet Werner, Guido
Klare, Ingo
Fleige, Carola
Geringer, Uta
Witte, Wolfgang
Just, Heinz-Michael
Ziegler, Renate
author_sort Werner, Guido
collection PubMed
description BACKGROUND: Vancomycin-resistant isolates of E. faecalis and E. faecium are of special concern and patients at risk of acquiring a VRE colonization/infection include also intensively-cared neonates. We describe here an ongoing high prevalence of VanB type E. faecium in a neonatal ICU hardly to identify by routine diagnostics. METHODS: During a 10 months’ key period 71 E. faecium isolates including 67 vanB-type isolates from 61 patients were collected non-selectively. Vancomycin resistance was determined by different MIC methods (broth microdilution, Vitek® 2) including two Etest® protocols (McFarland 0.5/2.0. on Mueller-Hinton/Brain Heart Infusion agars). Performance of three chromogenic VRE agars to identify the vanB type outbreak VRE was evaluated (Brilliance(TM) VRE agar, chromID(TM) VRE agar, CHROMagar(TM) VRE). Isolates were genotyped by SmaI- and CeuI-macrorestriction analysis in PFGE, plasmid profiling, vanB Southern hybridisations as well as MLST typing. RESULTS: Majority of vanB isolates (n = 56, 79%) belonged to a single ST192 outbreak strain type showing an identical PFGE pattern and analyzed representative isolates revealed a chromosomal localization of a vanB2-Tn5382 cluster type. Vancomycin MICs in cation-adjusted MH broth revealed a susceptible value of ≤4 mg/L for 31 (55%) of the 56 outbreak VRE isolates. Etest® vancomycin on MH and BHI agars revealed only two vanB VRE isolates with a susceptible result; in general Etest® MIC results were about 1 to 2 doubling dilutions higher than MICs assessed in broth and values after the 48 h readout were 0.5 to 1 doubling dilutions higher for vanB VRE. Of all vanB type VRE only three, three and two isolates did not grow on Brilliance(TM) VRE agar, chromID(TM) VRE agar and CHROMagar(TM) VRE, respectively. Permanent cross contamination via the patients’ surrounding appeared as a possible risk factor for permanent VRE colonization/infection. CONCLUSIONS: Low level expression of vanB resistance may complicate a proper routine diagnostics of vanB VRE and mask an ongoing high VRE prevalence. A high inoculum and growth on rich solid media showed the highest sensitivity in identifying vanB type resistance.
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spelling pubmed-35338212013-01-03 Vancomycin-resistant vanB-type Enterococcus faecium isolates expressing varying levels of vancomycin resistance and being highly prevalent among neonatal patients in a single ICU Werner, Guido Klare, Ingo Fleige, Carola Geringer, Uta Witte, Wolfgang Just, Heinz-Michael Ziegler, Renate Antimicrob Resist Infect Control Research BACKGROUND: Vancomycin-resistant isolates of E. faecalis and E. faecium are of special concern and patients at risk of acquiring a VRE colonization/infection include also intensively-cared neonates. We describe here an ongoing high prevalence of VanB type E. faecium in a neonatal ICU hardly to identify by routine diagnostics. METHODS: During a 10 months’ key period 71 E. faecium isolates including 67 vanB-type isolates from 61 patients were collected non-selectively. Vancomycin resistance was determined by different MIC methods (broth microdilution, Vitek® 2) including two Etest® protocols (McFarland 0.5/2.0. on Mueller-Hinton/Brain Heart Infusion agars). Performance of three chromogenic VRE agars to identify the vanB type outbreak VRE was evaluated (Brilliance(TM) VRE agar, chromID(TM) VRE agar, CHROMagar(TM) VRE). Isolates were genotyped by SmaI- and CeuI-macrorestriction analysis in PFGE, plasmid profiling, vanB Southern hybridisations as well as MLST typing. RESULTS: Majority of vanB isolates (n = 56, 79%) belonged to a single ST192 outbreak strain type showing an identical PFGE pattern and analyzed representative isolates revealed a chromosomal localization of a vanB2-Tn5382 cluster type. Vancomycin MICs in cation-adjusted MH broth revealed a susceptible value of ≤4 mg/L for 31 (55%) of the 56 outbreak VRE isolates. Etest® vancomycin on MH and BHI agars revealed only two vanB VRE isolates with a susceptible result; in general Etest® MIC results were about 1 to 2 doubling dilutions higher than MICs assessed in broth and values after the 48 h readout were 0.5 to 1 doubling dilutions higher for vanB VRE. Of all vanB type VRE only three, three and two isolates did not grow on Brilliance(TM) VRE agar, chromID(TM) VRE agar and CHROMagar(TM) VRE, respectively. Permanent cross contamination via the patients’ surrounding appeared as a possible risk factor for permanent VRE colonization/infection. CONCLUSIONS: Low level expression of vanB resistance may complicate a proper routine diagnostics of vanB VRE and mask an ongoing high VRE prevalence. A high inoculum and growth on rich solid media showed the highest sensitivity in identifying vanB type resistance. BioMed Central 2012-05-30 /pmc/articles/PMC3533821/ /pubmed/22958440 http://dx.doi.org/10.1186/2047-2994-1-21 Text en Copyright ©2012 Werner et al.; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research
Werner, Guido
Klare, Ingo
Fleige, Carola
Geringer, Uta
Witte, Wolfgang
Just, Heinz-Michael
Ziegler, Renate
Vancomycin-resistant vanB-type Enterococcus faecium isolates expressing varying levels of vancomycin resistance and being highly prevalent among neonatal patients in a single ICU
title Vancomycin-resistant vanB-type Enterococcus faecium isolates expressing varying levels of vancomycin resistance and being highly prevalent among neonatal patients in a single ICU
title_full Vancomycin-resistant vanB-type Enterococcus faecium isolates expressing varying levels of vancomycin resistance and being highly prevalent among neonatal patients in a single ICU
title_fullStr Vancomycin-resistant vanB-type Enterococcus faecium isolates expressing varying levels of vancomycin resistance and being highly prevalent among neonatal patients in a single ICU
title_full_unstemmed Vancomycin-resistant vanB-type Enterococcus faecium isolates expressing varying levels of vancomycin resistance and being highly prevalent among neonatal patients in a single ICU
title_short Vancomycin-resistant vanB-type Enterococcus faecium isolates expressing varying levels of vancomycin resistance and being highly prevalent among neonatal patients in a single ICU
title_sort vancomycin-resistant vanb-type enterococcus faecium isolates expressing varying levels of vancomycin resistance and being highly prevalent among neonatal patients in a single icu
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3533821/
https://www.ncbi.nlm.nih.gov/pubmed/22958440
http://dx.doi.org/10.1186/2047-2994-1-21
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