Genomic characterization of cocirculating Corynebacterium diphtheriae and non-diphtheritic Corynebacterium species among forcibly displaced Myanmar nationals, 2017-2019.
Microb Genom
; 9(9)2023 09.
Article
de En
| MEDLINE
| ID: mdl-37712831
ABSTRACT
Respiratory diphtheria is a serious infection caused by toxigenic Corynebacterium diphtheriae, and disease transmission mainly occurs through respiratory droplets. Between 2017 and 2019, a large diphtheria outbreak among forcibly displaced Myanmar nationals densely settled in Bangladesh was investigated. Here we utilized whole-genome sequencing (WGS) to characterize recovered isolates of C. diphtheriae and two co-circulating non-diphtheritic Corynebacterium (NDC) species - C. pseudodiphtheriticum and C. propinquum. C. diphtheriae isolates recovered from all 53 positive cases in this study were identified as toxigenic biovar mitis, exhibiting intermediate resistance to penicillin, and formed four phylogenetic clusters circulating among multiple refugee camps. Additional sequenced isolates collected from two patients showed co-colonization with non-toxigenic C. diphtheriae biovar gravis, one of which exhibited decreased susceptibility to the first-line antibiotics and harboured a novel 23-kb multidrug resistance plasmid. Results of phylogenetic reconstruction and virulence-related gene contents of the recovered NDC isolates indicated they were likely commensal organisms, though 80.4â%(45/56) were not susceptible to erythromycin, and most showed high minimum inhibition concentrations against azithromycin. These results demonstrate the high resolution with which WGS can aid molecular investigation of diphtheria outbreaks, through the quantification of bacterial genetic relatedness, as well as the detection of virulence factors and antibiotic resistance markers among case isolates.
Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Corynebacterium diphtheriae
/
Diphtérie
Type d'étude:
Prognostic_studies
Limites:
Humans
Pays/Région comme sujet:
Asia
Langue:
En
Journal:
Microb Genom
Année:
2023
Type de document:
Article
Pays d'affiliation:
États-Unis d'Amérique