Journal article
Azithromycin resistance in Shigella spp. in Southeast Asia
- Abstract:
- Infection by Shigella spp. is a common cause of dysentery in Southeast Asia. Antimicrobials are thought to be beneficial for treatment, however antimicrobial resistance in Shigella spp. is becoming widespread. We aimed to assess the frequency and mechanisms associated with decreased susceptibility to azithromycin in Southeast Asian Shigella isolates and use these data to assess appropriate susceptibility breakpoints. Shigella isolated in Vietnam and Laos were screened for susceptibility against azithromycin (15μg) by disc diffusion and minimum inhibitory concentration (MIC). Phenotypic resistance was confirmed by PCR amplification of macrolide resistance loci. We compared the genetic relationships and plasmid contents of azithromycin resistant S. sonnei using whole genome sequences. From 475 available Shigella spp. isolated in Vietnam and Laos between 1994 and 2012, 6/181 S. flexneri (3.3%, MIC≥16g/L) and 16/294 S. sonnei (5.4%, MIC≥32g/L) were phenotypically resistant to azithromycin. PCR amplification confirmed a resistance mechanism in 22/475 (4.6%) isolates (19 mphA and 3 ermB). Susceptibility data demonstrated the acceptability of S. flexneri (MIC≥16g/L, zone≤15mm) and S. sonnei (MIC≥32g/L, zone≤11mm) breakpoints with <3% discrepancy. Phylogenetic analysis demonstrated that decreased susceptibility has arisen sporadically in Vietnamese S. sonnei on at least seven occasions between 2000 and 2009, but failed to become established. While the proposed susceptibility breakpoints may allow better recognition of resistant isolates, additional studies are required to assess the impact on clinical outcome. The potential emergence of azithromycin resistance highlights the need for alternative management options for Shigella infections in endemic countries.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
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(Preview, Version of record, pdf, 1.5MB, Terms of use)
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- Publisher copy:
- 10.1128/aac.01748-17
Authors
+ Royal Society
More from this funder
- Funding agency for:
- Baker, S
- Grant:
- Sir Henry Dale 365 Fellowship grant number 10008/Z/12/Z
- Sir Henry Dale 365 Fellowship grant number 10008/Z/12/Z to SB
+ Wellcome Trust
More from this funder
- Funding agency for:
- Thwaites, G
- Baker, S
- Newton, P
- Grant:
- 89276/2/09/2
- Sir Henry Dale 365 Fellowship grant number 10008/Z/12/Z
- 106698/Z/14/ZtoDABD,PNN,RP
- VD
- 106698/Z/14/Z
+ National Institutes for Health Research
More from this funder
- Grant:
- Academic Clinical 360 Lectureship grant number 3557 to TCD
- Publisher:
- American Society for Microbiology
- Journal:
- Antimicrobial Agents and Chemotherapy More from this journal
- Volume:
- 62
- Issue:
- 4
- Pages:
- e01748-17
- Publication date:
- 2018-01-29
- Acceptance date:
- 2017-11-02
- DOI:
- EISSN:
-
1098-6596
- ISSN:
-
0066-4804
- Pmid:
-
29378707
- Language:
-
English
- Keywords:
- Pubs id:
-
pubs:822609
- UUID:
-
uuid:6f1710fd-1f74-4104-be5b-c91a82106fe4
- Local pid:
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pubs:822609
- Source identifiers:
-
822609
- Deposit date:
-
2018-02-03
Terms of use
- Copyright holder:
- Darton et al
- Copyright date:
- 2018
- Notes:
-
Copyright © 2018 Darton et al.
This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.
- Licence:
- CC Attribution (CC BY)
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