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Molecular epidemiology of extended-spectrum beta-lactamase (ESBL) carrying Enterobacteriaceae at ABM University Health Board. / Caron Jones

Swansea University Author: Caron Jones

Abstract

Extended-spectrum beta-lactamases (ESBL) mediate resistance to 3rd generation cephalosporins and aztreonam in Enterobacteriaceae and pose major clinical problems. Screened Enterobacteriaceae were collected from PHW Microbiology ABM Swansea laboratory and were demonstrated phenotypically to be ESBL-...

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Published: 2012
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
URI: https://cronfa.swan.ac.uk/Record/cronfa42241
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spelling 2018-08-02T16:24:28.5421834 v2 42241 2018-08-02 Molecular epidemiology of extended-spectrum beta-lactamase (ESBL) carrying Enterobacteriaceae at ABM University Health Board. fd34481e7fd5011d193da646aea4bd23 NULL Caron Jones Caron Jones true true 2018-08-02 Extended-spectrum beta-lactamases (ESBL) mediate resistance to 3rd generation cephalosporins and aztreonam in Enterobacteriaceae and pose major clinical problems. Screened Enterobacteriaceae were collected from PHW Microbiology ABM Swansea laboratory and were demonstrated phenotypically to be ESBL- producers by BSAC methods. Isolates were identified using the BD Phoenix Automated system and Bruker Daltonics MALDI Biotyper. 138 isolates were genetically defined as ESBL-producers (103 Escherichia coli, 32 Klebsiella spp., 2 Enterobacter cloacae and 1 Citrobacter freundii) and 4 isolates (2 E. coli, 1 Enterobacter cloacae and 1 Morganella morganii) were genetically confirmed as AmpC-producers. PCR analysis revealed that the most prevalent ESBLs were CTX-M (n=133), predominantly Group 1 (n=128), of which 51% (66/128) contained the I526-CTX- M-15 link region, which is characteristic for epidemic E. coli strain A. PFGE confirmed that these isolates had a clonal relatedness to epidemic E. coli strain A. Allele-specific PCR revealed that all E. coli positive for I526-CTX-M-15 belonged to clone 025b-ST131 (found internationally), which has a high virulence potential and encompasses diverse PFGE patterns. With the molecular epidemiology established; the sensitivity and performance of phenotypic screening and confirmatory assays were analysed so that optimal strategies to handle difficult-to-identify ESBL resistance traits could be determined. In this study, the sensitivity of ESBL screening increased to 100% when ceftazidime was used alongside cefpodoxime. Isolates harbouring ESBL genes are often difficult to treat, as options are greatly limited. Susceptibility to various well-established antibiotics, along with temocillin and tigecycline, were investigated. Temocillin and tigecycline were effective against 98% and 89% of all isolates tested. The carbapenems were the most active antibiotics with 100% of isolates susceptible to imipenem and meropenem and 99% susceptible to ertapenem. Biofilm production in E. coli was also investigated. The pgaABCD gene locus was detected in all ESBL and AmpC-producing E. coli isolates (n=105); however, only 38% of these produced a phenotypic biofilm. E-Thesis Epidemiology.;Microbiology. 31 12 2012 2012-12-31 COLLEGE NANME Nursing COLLEGE CODE Swansea University Doctoral Ph.D 2018-08-02T16:24:28.5421834 2018-08-02T16:24:28.5421834 Faculty of Medicine, Health and Life Sciences School of Health and Social Care - Nursing Caron Jones NULL 1 0042241-02082018162439.pdf 10797949.pdf 2018-08-02T16:24:39.1200000 Output 13164806 application/pdf E-Thesis true 2018-08-02T16:24:39.1200000 false
title Molecular epidemiology of extended-spectrum beta-lactamase (ESBL) carrying Enterobacteriaceae at ABM University Health Board.
spellingShingle Molecular epidemiology of extended-spectrum beta-lactamase (ESBL) carrying Enterobacteriaceae at ABM University Health Board.
Caron Jones
title_short Molecular epidemiology of extended-spectrum beta-lactamase (ESBL) carrying Enterobacteriaceae at ABM University Health Board.
title_full Molecular epidemiology of extended-spectrum beta-lactamase (ESBL) carrying Enterobacteriaceae at ABM University Health Board.
title_fullStr Molecular epidemiology of extended-spectrum beta-lactamase (ESBL) carrying Enterobacteriaceae at ABM University Health Board.
title_full_unstemmed Molecular epidemiology of extended-spectrum beta-lactamase (ESBL) carrying Enterobacteriaceae at ABM University Health Board.
title_sort Molecular epidemiology of extended-spectrum beta-lactamase (ESBL) carrying Enterobacteriaceae at ABM University Health Board.
author_id_str_mv fd34481e7fd5011d193da646aea4bd23
author_id_fullname_str_mv fd34481e7fd5011d193da646aea4bd23_***_Caron Jones
author Caron Jones
author2 Caron Jones
format E-Thesis
publishDate 2012
institution Swansea University
college_str Faculty of Medicine, Health and Life Sciences
hierarchytype
hierarchy_top_id facultyofmedicinehealthandlifesciences
hierarchy_top_title Faculty of Medicine, Health and Life Sciences
hierarchy_parent_id facultyofmedicinehealthandlifesciences
hierarchy_parent_title Faculty of Medicine, Health and Life Sciences
department_str School of Health and Social Care - Nursing{{{_:::_}}}Faculty of Medicine, Health and Life Sciences{{{_:::_}}}School of Health and Social Care - Nursing
document_store_str 1
active_str 0
description Extended-spectrum beta-lactamases (ESBL) mediate resistance to 3rd generation cephalosporins and aztreonam in Enterobacteriaceae and pose major clinical problems. Screened Enterobacteriaceae were collected from PHW Microbiology ABM Swansea laboratory and were demonstrated phenotypically to be ESBL- producers by BSAC methods. Isolates were identified using the BD Phoenix Automated system and Bruker Daltonics MALDI Biotyper. 138 isolates were genetically defined as ESBL-producers (103 Escherichia coli, 32 Klebsiella spp., 2 Enterobacter cloacae and 1 Citrobacter freundii) and 4 isolates (2 E. coli, 1 Enterobacter cloacae and 1 Morganella morganii) were genetically confirmed as AmpC-producers. PCR analysis revealed that the most prevalent ESBLs were CTX-M (n=133), predominantly Group 1 (n=128), of which 51% (66/128) contained the I526-CTX- M-15 link region, which is characteristic for epidemic E. coli strain A. PFGE confirmed that these isolates had a clonal relatedness to epidemic E. coli strain A. Allele-specific PCR revealed that all E. coli positive for I526-CTX-M-15 belonged to clone 025b-ST131 (found internationally), which has a high virulence potential and encompasses diverse PFGE patterns. With the molecular epidemiology established; the sensitivity and performance of phenotypic screening and confirmatory assays were analysed so that optimal strategies to handle difficult-to-identify ESBL resistance traits could be determined. In this study, the sensitivity of ESBL screening increased to 100% when ceftazidime was used alongside cefpodoxime. Isolates harbouring ESBL genes are often difficult to treat, as options are greatly limited. Susceptibility to various well-established antibiotics, along with temocillin and tigecycline, were investigated. Temocillin and tigecycline were effective against 98% and 89% of all isolates tested. The carbapenems were the most active antibiotics with 100% of isolates susceptible to imipenem and meropenem and 99% susceptible to ertapenem. Biofilm production in E. coli was also investigated. The pgaABCD gene locus was detected in all ESBL and AmpC-producing E. coli isolates (n=105); however, only 38% of these produced a phenotypic biofilm.
published_date 2012-12-31T03:52:35Z
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score 11.014067

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