Publications
Detailed Information
Fluoroquinolone antimicrobial resistance of Escherichia coli isolated from swine feces in Korea
DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | 박용호 | - |
dc.contributor.author | 허윤성 | - |
dc.date.accessioned | 2017-07-19T11:34:25Z | - |
dc.date.available | 2017-07-19T11:34:25Z | - |
dc.date.issued | 2017-02 | - |
dc.identifier.other | 000000140963 | - |
dc.identifier.uri | https://hdl.handle.net/10371/133773 | - |
dc.description | 학위논문 (석사)-- 서울대학교 대학원 : 수의학과, 2017. 2. 박용호. | - |
dc.description.abstract | In this study, the fluoroquinolone (FQ) resistance rate and mechanisms in FQ-resistant Escherichia coli isolated from swine fecal samples have been investigated. A total of 171 E. coli isolates were collected from 237 swine fecal samples (72.2%). Of these, 59 isolates (34.5%) were confirmed as FQ-resistant E. coli by the disk diffusion method. Of the FQ-resistant isolates, three major FQ-resistance mechanisms were investigated: i) amino acid substitutions in quinolone resistance-determining regions (QRDRs), ii) acquisition of plasmid-mediated quinolone-resistance genes (PMQRs | - |
dc.description.abstract | qnrA, qnrB, qnrS, qepA, and aac(6)-Ib-cr), and iii) increased efflux pump activity. All 59 ciprofloxacin (CIP)-resistant isolates had gyrA mutations (100%) | - |
dc.description.abstract | of these 59 isolates, 58 had mutations in parC (98.3%), 22 had mutations in parE (37.3%), and none had mutations in gyrB. The predominant mutation was Ser83Leu in gyrA, followed by Ser80Ile in parC, and Ser458Ala in parE. Nine isolates harbored PMQR genes, including qnrS (n = 7, 11.9%), qepA (n = 1, 1.7%), and aac(6)-Ib-cr (n = 1, 1.7%). Efflux pump activity was found in 56 isolates (94.9%). FQ-resistant E. coli had high minimum inhibitory concentrations against CIP, and most isolates were multidrug-resistant. Compared with previous studies in Korea, the prevalence of FQ resistance and PMQR genes had increased significantly in swine. Although the use of FQ as a feed additives is prohibited in Korea, use for self-treatment and therapeutic purposes has been increasing, which may be responsible for the higher FQ-resistance rate observed in this study. Therefore, prudent use of FQ in animal farms is needed to reduce the evolution of FQ-resistant bacteria in Korea. | - |
dc.description.tableofcontents | I.INTRODUCTION 1
II.MATERIALS AND METHODS 3 1.1 Isolation and identification of FQ-resistant E. coli 3 1.2 Minimum inhibitory concentrations (MICs) of nalidixic acid (NA) and ciprofloxacin (CIP) 4 1.3 Antibiogram of FQ-resistant E. coli against other antimicrobials 4 1.4 Identification of mutations in QRDRs and detection of PMQRs 5 1.5 Organic solvent tolerance (OST) test 5 1.6 Statistical analysis 6 III.RESULTS 7 1.1 Isolation of FQ-resistant E. coli and antimicrobial susceptibility tests 7 1.2 Correlation of CIP MIC and frequencies of MDR and ESBL E. coli 7 1.3 Presence of amino acid substitutions in QRDRs in FQ-resistant E. coli 8 1.4 Detection of PMQR genes in FQ-resistant E. coli 9 1.5 Phenotypic efflux pump activity 9 IV.DISCUSSION 10 V.REFERENCES 21 VI.국문초록 28 | - |
dc.format | application/pdf | - |
dc.format.extent | 659379 bytes | - |
dc.format.medium | application/pdf | - |
dc.language.iso | en | - |
dc.publisher | 서울대학교 대학원 | - |
dc.subject | quinolone | - |
dc.subject | fluoroquinolone | - |
dc.subject | antimicrobial resistance | - |
dc.subject | Escherichia coli | - |
dc.subject | pig | - |
dc.subject.ddc | 636 | - |
dc.title | Fluoroquinolone antimicrobial resistance of Escherichia coli isolated from swine feces in Korea | - |
dc.type | Thesis | - |
dc.description.degree | Master | - |
dc.citation.pages | 30 | - |
dc.contributor.affiliation | 수의과대학 수의학과 | - |
dc.date.awarded | 2017-02 | - |
- Appears in Collections:
- Files in This Item:
Item View & Download Count
Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.