scholarly journals Whole-Genome Sequencing Analysis of a stx-Negative Escherichia coli O63:H6 Isolate Associated with Hemolytic Uremic Syndrome

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1823
Author(s):  
Tae Yeul Kim ◽  
Tae-Min La ◽  
Taesoo Kim ◽  
Sun Ae Yun ◽  
Sang-Won Lee ◽  
...  

Shiga toxin-encoding genes (stx) of enterohemorrhagic Escherichia coli (EHEC) can be lost during infection or in vitro cultivation, and in clinical practice, it is difficult to distinguish EHEC that have lost stx (EHEC-LST) from enteropathogenic E. coli (EPEC), as both are stx-negative and eae-positive. In this study, we performed whole-genome sequencing (WGS) of a stx-negative, eae-positive E. coli O63:H6 isolate from a child with hemolytic uremic syndrome and compared its genome with those of nine E. coli O63:H6 strains in public databases. Virulence gene profiles were analyzed and core-genome multilocus sequence typing (cgMLST) was conducted. The virulence gene profile of our isolate was consistent with EHEC, except for the absence of stx, and the isolate clustered with seven EHEC strains but was distant from two EPEC strains in cgMLST. In genome alignment, our isolate exhibited a high nucleotide identity with EHEC strain 377323_2f but displayed a gap corresponding to the stx-harboring prophage sequence. Overall, our isolate was genetically closely related to EHEC strains, consistent with this being an EHEC-LST strain. As EHEC-LST may be misdiagnosed as EPEC in routine laboratories, comparative genomic analysis using WGS can be useful to determine whether stx-negative and eae-positive isolates are EHEC-LST or EPEC.

2015 ◽  
Vol 53 (11) ◽  
pp. 3530-3538 ◽  
Author(s):  
Mithila Ferdous ◽  
Kai Zhou ◽  
Alexander Mellmann ◽  
Stefano Morabito ◽  
Peter D. Croughs ◽  
...  

The ability ofEscherichia coliO157:H7 to induce cellular damage leading to disease in humans is related to numerous virulence factors, most notably thestxgene, encoding Shiga toxin (Stx) and carried by a bacteriophage. Loss of the Stx-encoding bacteriophage may occur during infection or culturing of the strain. Here, we collectedstx-positive andstx-negative variants ofE. coliO157:H7/NM (nonmotile) isolates from patients with gastrointestinal complaints. Isolates were characterized by whole-genome sequencing (WGS), and their virulence properties and phylogenetic relationship were determined. Because of the presence of theeaegene but lack of thebfpAgene, thestx-negative isolates were considered atypical enteropathogenicE. coli(aEPEC). However, they had phenotypic characteristics similar to those of the Shiga toxin-producingE. coli(STEC) isolates and belonged to the same sequence type, ST11. Furthermore, EPEC and STEC isolates shared similar virulence genes, the locus of enterocyte effacement region, and plasmids. Core genome phylogenetic analysis using a gene-by-gene typing approach showed that the sorbitol-fermenting (SF)stx-negative isolates clustered together with an SF STEC isolate and that one non-sorbitol-fermenting (NSF)stx-negative isolate clustered together with NSF STEC isolates. Therefore, thesestx-negative isolates were thought either to have lost the Stx phage or to be a progenitor of STEC O157:H7/NM. As detection of STEC infections is often based solely on the identification of the presence ofstxgenes, these may be misdiagnosed in routine laboratories. Therefore, an improved diagnostic approach is required to manage identification, strategies for treatment, and prevention of transmission of these potentially pathogenic strains.


Author(s):  
Saoussen Oueslati ◽  
Cécile Emeraud ◽  
Victor Grosperrin ◽  
Marc Levy ◽  
Garance Cotellon ◽  
...  

The whole genome sequencing analysis revealed a polyclonal dissemination of NDM-1 and NDM-9 variants in E. coli (n=20) and K. pneumoniae (n=2) in Tahiti since 2015 via interspecies transfer of three different blaNDM-carrying plasmids (IncR, IncHI2 and IncF) and patient-to-patient cross-transmissions. It highlights the potential risk of importation of NDM producers in France where French Polynesia is not considered stricto senso as a foreign country from which repatriated patients have to be screened.


2021 ◽  
Vol 27 (5) ◽  
pp. 1509-1512
Author(s):  
Kenichi Lee ◽  
Atsushi Iguchi ◽  
Kazuhiro Uda ◽  
Sohshi Matsumura ◽  
Isao Miyairi ◽  
...  

2021 ◽  
Author(s):  
Yang Zhong ◽  
Siyao Guo ◽  
Glendon Ong Hong Ming ◽  
Joergen Schlundt

Objective: Escherichia coli ST410 with blaNDM-5 has been increasingly detected as multidrug resistance pathogens globally, even though there are very few reports of infections caused by blaNDM-5 producing E. coli in Singapore. And significantly limit sequencing information of blaNDM-5 carried E .coli strain from Singapore. In 2018, our group obtained a carbapenem resistance E. coli ST410 strain SrichA-1 isolated from reservoir water in Singapore, determined to harbor the NDM-5 gene. (BioSample Accession: SAMN18579051). Methods: The susceptibility test to antimicrobials was performed with microdilution minimum inhibitory concentration (MIC) test and interpreted according to the Clinical And Laboratory Standards Institute (CLSI) -M100 standards. The genomic DNA of this strain was extracted and send for Whole-genome sequencing(WGS) with the Illumina platform. The WGS analysis was processed with the Center for Genomic Epidemiology (CGE, DTU) server. Results: During the minimum inhibitory concentration (MIC) test, SrichA-1 has shown strong resistance to all the beta-lactams, including cephalosporin and carbapenem, which can not be inhibited by the clavulanic acid. Further whole genome sequencing analysis has shown that the strain harboring five beta-lactamase genes covers all class A to D, including the carbapenemase genes as blaNDM-5. Conclusion: Here, we reported the complete chromosome sequence of this isolate as well as the sequence of a cycler plasmid. The pSGNDM-5 plasmid was furtherly identified to carry four beta-lactamase genes, including blaNDM-5, blaCTX-M-15, blaTEM-1B, blaOXA-1, while a blaCMY-2 was detected to be located on the chromosome.


Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1504
Author(s):  
Frederick Adzitey ◽  
Jonathan Asante ◽  
Hezekiel M. Kumalo ◽  
Rene B. Khan ◽  
Anou M. Somboro ◽  
...  

Escherichia coli are among the most common foodborne pathogens associated with infections reported from meat sources. This study investigated the virulome, pathogenicity, stress response factors, clonal lineages, and the phylogenomic relationship of E. coli isolated from different meat sources in Ghana using whole-genome sequencing. Isolates were screened from five meat sources (beef, chevon, guinea fowl, local chicken, and mutton) and five areas (Aboabo, Central market, Nyorni, Victory cinema, and Tishegu) based in the Tamale Metropolis, Ghana. Following microbial identification, the E. coli strains were subjected to whole-genome sequencing. Comparative visualisation analyses showed different DNA synteny of the strains. The isolates consisted of diverse sequence types (STs) with the most common being ST155 (n = 3/14). Based Upon Related Sequence Types (eBURST) analyses of the study sequence types identified four similar clones, five single-locus variants, and two satellite clones (more distantly) with global curated E. coli STs. All the isolates possessed at least one restriction-modification (R-M) and CRISPR defence system. Further analysis revealed conserved stress response mechanisms (detoxification, osmotic, oxidative, and periplasmic stress) in the strains. Estimation of pathogenicity predicted a higher average probability score (Pscore ≈ 0.937), supporting their pathogenic potential to humans. Diverse virulence genes that were clonal-specific were identified. Phylogenomic tree analyses coupled with metadata insights depicted the high genetic diversity of the E. coli isolates with no correlation with their meat sources and areas. The findings of this bioinformatic analyses further our understanding of E. coli in meat sources and are broadly relevant to the design of contamination control strategies in meat retail settings in Ghana.


2020 ◽  
Vol 6 (7) ◽  
Author(s):  
Bede Constantinides ◽  
Kevin K. Chau ◽  
T. Phuong Quan ◽  
Gillian Rodger ◽  
Monique I. Andersson ◽  
...  

Escherichia coli and Klebsiella spp. are important human pathogens that cause a wide spectrum of clinical disease. In healthcare settings, sinks and other wastewater sites have been shown to be reservoirs of antimicrobial-resistant E. coli and Klebsiella spp., particularly in the context of outbreaks of resistant strains amongst patients. Without focusing exclusively on resistance markers or a clinical outbreak, we demonstrate that many hospital sink drains are abundantly and persistently colonized with diverse populations of E. coli , Klebsiella pneumoniae and Klebsiella oxytoca , including both antimicrobial-resistant and susceptible strains. Using whole-genome sequencing of 439 isolates, we show that environmental bacterial populations are largely structured by ward and sink, with only a handful of lineages, such as E. coli ST635, being widely distributed, suggesting different prevailing ecologies, which may vary as a result of different inputs and selection pressures. Whole-genome sequencing of 46 contemporaneous patient isolates identified one (2 %; 95 % CI 0.05–11 %) E. coli urine infection-associated isolate with high similarity to a prior sink isolate, suggesting that sinks may contribute to up to 10 % of infections caused by these organisms in patients on the ward over the same timeframe. Using metagenomics from 20 sink-timepoints, we show that sinks also harbour many clinically relevant antimicrobial resistance genes including bla CTX-M, bla SHV and mcr, and may act as niches for the exchange and amplification of these genes. Our study reinforces the potential role of sinks in contributing to Enterobacterales infection and antimicrobial resistance in hospital patients, something that could be amenable to intervention. This article contains data hosted by Microreact.


2019 ◽  
Vol 82 (8) ◽  
pp. 1398-1404 ◽  
Author(s):  
RENATE BOSS ◽  
JOERG HUMMERJOHANN

ABSTRACT Shiga toxin–producing Escherichia coli (STEC) strains are often found in food and cause human infections. Although STEC O157:H7 is most often responsible for human disease, various non-O157 subtypes have caused individual human infections or outbreaks. The importance of STEC serogroup typing is decreasing while detection of virulence gene patterns has become more relevant. Whole genome sequencing (WGS) reveals the entire spectrum of pathogen information, such as toxin variant, serotype, sequence type, and virulence factors. Flour has not been considered as a vector for STEC; however, this product has been associated with several STEC outbreaks in the last decade. Flour is a natural product, and milling does not include a germ-reducing step. Flour is rarely eaten raw, but the risks associated with the consumption of unbaked dough are probably underestimated. The aim of this study was to determine the prevalence of STEC in flour samples (n = 93) collected from Swiss markets and to fully characterize the isolates by PCR assay and WGS. The prevalence of STEC in these flour samples was 10.8% as indicated by PCR, and a total of 10 STEC strains were isolated (two flour samples were positive for two STEC subtypes). We found one stx2-positve STEC isolate belonging to the classic serogroups frequently associated with outbreaks that could potentially cause severe disease. However, we also found several other common or less common STEC subtypes with diverse virulence patterns. Our results reveal the benefits of WGS as a characterization tool and that flour is a potentially and probably underestimated source for STEC infections in humans.


1998 ◽  
Vol 36 (1) ◽  
pp. 24-29 ◽  
Author(s):  
Clemens Hofinger ◽  
Helge Karch ◽  
Herbert Schmidt

In this study, pColD157, a 6.7-kb colicinogenic plasmid of enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain CL40cu, was characterized by restriction mapping and determination of its complete nucleotide sequence. The sequence consists of 6,675 bp and shows a high degree of similarity to the nucleotide sequence of colicinogenic plasmids pColD-CA23 and pColK. Seven potential genes were located on pColD157, three of which were closely related (>97.9%) to the colicin D structural gene and the corresponding immunity and lysis genes of plasmid pColD-CA23, and these were therefore designatedcda, cdi, and cdl, respectively, using the reference extension -CL40 for differentiation. The adjacent 3′ region is related to the origin of replication of pColD-CA23. In contrast, the remaining part of the plasmid harbors a cluster of genes, closely related to the mobilization genes of pColK, which is followed by a 0.3-kb stretch homologous to the pColK resolution function. These determinants were designated mbdA, mbdB,mbdC, and mbdD and cdr, respectively. Southern blot analysis was performed with a probe specific for the cda gene of pColD157 and two groups of EHEC O157:H7 isolates from patients with diarrhea or hemolytic-uremic syndrome resident in Germany. Whereas 16 of 46 E. coli O157 strains isolated between 1987 and 1991 harbored plasmid pColD157, only 1 of 50 strains isolated during 1996 carried this plasmid. In addition, all strains harboring plasmid pColD157 were shown to have colicinogenic activity.


2017 ◽  
Vol 22 (16) ◽  
Author(s):  
Marta Corbella ◽  
Bianca Mariani ◽  
Carolina Ferrari ◽  
Francesco Comandatore ◽  
Erika Scaltriti ◽  
...  

We describe three cases of bloodstream infection caused by colistin-resistant Escherichia coli in patients in a tertiary hospital in Italy, between August 2016 and January 2017. Whole genome sequencing detected the mcr-1 gene in three isolated strains belonging to different sequence types (STs). This occurrence of three cases with mcr-1-positive E. coli belonging to different STs in six months suggests a widespread problem in settings where high multidrug resistance is endemic such as in Italy.


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