scholarly journals Utility of whole-genome sequencing during an investigation of multiple foodborne outbreaks of Shigella sonnei

2021 ◽  
Vol 149 ◽  
Author(s):  
Amy F. W. Mikhail ◽  
Monique Pereboom ◽  
Lara Utsi ◽  
Jeremy Hawker ◽  
Jonathan Lighthill ◽  
...  

Abstract In April 2018, Public Health England was notified of cases of Shigella sonnei who had eaten food from three different catering outlets in England. The outbreaks were initially investigated as separate events, but whole-genome sequencing (WGS) showed they were caused by the same strain. The investigation included analyses of epidemiological data, the food chain and microbiological examination of food samples. WGS was used to determine the phylogenetic relatedness and antimicrobial resistance profile of the outbreak strain. Ultimately, 33 cases were linked to this outbreak; the majority had eaten food from seven outlets specialising in Indian or Middle Eastern cuisine. Five outlets were linked to two or more cases, all of which used fresh coriander although a shared supplier was not identified. An investigation at one of the venues recorded that 86% of cases reported eating dishes with coriander as an ingredient or garnish. Four cases were admitted to hospital and one had evidence of treatment failure with ciprofloxacin. Phylogenetic analysis showed that the outbreak strain was part of a wider multidrug-resistant clade associated with travel to Pakistan. Poor hygiene practices during cultivation, distribution or preparation of fresh produce are likely contributing factors.

2015 ◽  
Vol 144 (3) ◽  
pp. 576-581 ◽  
Author(s):  
M. MOHAMMED ◽  
N. DELAPPE ◽  
J. O'CONNOR ◽  
P. McKEOWN ◽  
P. GARVEY ◽  
...  

SUMMARYSalmonella enterica subsp. enterica serovar Dublin is an uncommon cause of human salmonellosis; however, a relatively high proportion of cases are associated with invasive disease. The serotype is associated with cattle. A geographically diffuse outbreak of S. Dublin involving nine patients occurred in Ireland in 2013. The source of infection was not identified. Typing of outbreak associated isolates by pulsed-field gel electrophoresis (PFGE) was of limited value because PFGE has limited discriminatory power for S. Dublin. Whole genome sequencing (WGS) showed conclusively that the isolates were closely related to each other, to an apparently unrelated isolate from 2011 and distinct from other isolates that were not readily distinguishable by PFGE.


2019 ◽  
Vol 57 (9) ◽  
Author(s):  
Xuebing Wang ◽  
Haijian Zhou ◽  
Dongke Chen ◽  
Pengcheng Du ◽  
Ruiting Lan ◽  
...  

ABSTRACT Corynebacterium striatum is an emerging multidrug-resistant (MDR) pathogen that occurs primarily among immunocompromised and chronically ill patients. However, little is known about the genomic diversity of C. striatum, which contributes to its long-term persistence and transmission in hospitals. In this study, a total of 192 C. striatum isolates obtained from 14 September 2017 to 29 March 2018 in a hospital in Beijing, China, were analyzed by antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE). Whole-genome sequencing was conducted on 91 isolates. Nearly all isolates (96.3%, 183/190) were MDR. The highest resistance rate was observed for ciprofloxacin (99.0%, 190/192), followed by cefotaxime (90.6%, 174/192) and erythromycin (89.1%, 171/192). PFGE separated the 192 isolates into 79 pulsotypes, and differences in core genome single-nucleotide polymorphisms (SNPs) partitioned the 91 isolates sequenced into four clades. Isolates of the same pulsotype were identical or nearly identical at the genome level, with some exceptions. Two dominant subclones, clade 3a, and clade 4a, were responsible for the hospital-wide dissemination. Genomic analysis further revealed nine resistance genes mobilized by eight unique cassettes. PFGE and whole-genome sequencing revealed that the C. striatum isolates studied were the result mainly of predominant clones spreading in the hospital. C. striatum isolates in the hospital progressively acquired resistance to antimicrobial agents, demonstrating that isolates of C. striatum may adapt rapidly through the acquisition and accumulation of resistance genes and thus evolve into dominant and persistent clones. These insights will be useful for the prevention of C. striatum infection in hospitals.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S309-S309 ◽  
Author(s):  
Mariana Castanheira ◽  
Jill Lindley ◽  
Holly Huynh ◽  
Rodrigo E Mendes ◽  
Olga Lomovskaya

Abstract Background CREs have been described worldwide and these isolates are often multidrug resistant with few therapeutic options remaining active against them. New β-lactam (BL)/β-lactamase inhibitor (BLI) combinations recently approved are active against KPC and some OXA-48 producers, but not against isolates producing metallo-β-lactamases (MBLs). We evaluated the activity of QPX7728 (QPX), a novel BLI paired with various BLs against a collection of CRE isolates characterized for the presence of carbapenemases. Methods A total of 508 CRE clinical isolates were susceptibility (S) tested by reference broth microdilution methods against meropenem (MER), tebipenem (TEB), cefepime (FEP), ceftolozane (TOL), and ertapenem (ETP), and meropenem (MEM) combined with QPX at fixed 2, 4, and 8 mg/L. Agents were provided by Qpex Biopharma except for FEP, ETP, and MEM. Carbapenemases were detected using PCR/sequencing or whole-genome sequencing. Results All BLs had limited activity against CRE isolates (MIC50/90, ≥32/ >32 mg/L) and QPX lowered the MIC for all agents (figure). Against 157 isolates carrying serine-carbapenemase (SCarb) genes (153 KPC-producers), MEM or ETP plus QPX at fixed 4 or 8 mg/L displayed MIC50 at ≤ 0.03 mg/L and MIC90 ranging from 0.12 to 0.5 mg/L. QPX lowered the FEP or TOL MIC50 to ≤ 0.25 mg/L and MIC90 to 0.25, 0.5 or 1 mg/L depending on the BLI concentration. Over 98.0% of the 150 isolates harboring OXA-48-like genes were inhibited by FEP, TOL, ETP or MEM plus QPX at ≤2 mg/L. Similarly, MEM, FEP, TOL and ETP + QPX inhibited >98.0% of the 51 CREs that did not carry carbapenemases at ≤2 mg/L when using a higher BLI concentration. The activity of FEP (MIC50/90, 0.06/1 mg/L), ETP (MIC50/90, 0.03/4 mg/L), and MEM (MIC50/90, ≤ 0.015/2 mg/L) was mostly restored when 8 mg/L of QPX was combined with these agents and tested against 150 MBL-producing isolates. Conclusion QPX restored the activity of several BLs when tested against 508 CRE isolates that include 157 harboring SCarb, 150 OXA-48-like-producers, and 150 MBL-producing isolates. Further development of this BLI with inhibitory activity against all carbapenemase types seems warranted. Disclosures All authors: No reported disclosures.


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