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Yongmei Ji

Bio: Yongmei Ji is an academic researcher from Life Technologies. The author has contributed to research in topics: Cronobacter & Outbreak. The author has an hindex of 3, co-authored 5 publications receiving 805 citations.

Papers
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Journal ArticleDOI
20 Jul 2011-PLOS ONE
TL;DR: It is suggested that by stepwise gain and loss of chromosomal and plasmid-encoded virulence factors, a highly pathogenic hybrid of EAEC and EHEC emerged as the current outbreak clone.
Abstract: An ongoing outbreak of exceptionally virulent Shiga toxin (Stx)-producing Escherichia coli O104:H4 centered in Germany, has caused over 830 cases of hemolytic uremic syndrome (HUS) and 46 deaths since May 2011. Serotype O104:H4, which has not been detected in animals, has rarely been associated with HUS in the past. To prospectively elucidate the unique characteristics of this strain in the early stages of this outbreak, we applied whole genome sequencing on the Life Technologies Ion Torrent PGM™ sequencer and Optical Mapping to characterize one outbreak isolate (LB226692) and a historic O104:H4 HUS isolate from 2001 (01-09591). Reference guided draft assemblies of both strains were completed with the newly introduced PGM™ within 62 hours. The HUS-associated strains both carried genes typically found in two types of pathogenic E. coli, enteroaggregative E. coli (EAEC) and enterohemorrhagic E. coli (EHEC). Phylogenetic analyses of 1,144 core E. coli genes indicate that the HUS-causing O104:H4 strains and the previously published sequence of the EAEC strain 55989 show a close relationship but are only distantly related to common EHEC serotypes. Though closely related, the outbreak strain differs from the 2001 strain in plasmid content and fimbrial genes. We propose a model in which EAEC 55989 and EHEC O104:H4 strains evolved from a common EHEC O104:H4 progenitor, and suggest that by stepwise gain and loss of chromosomal and plasmid-encoded virulence factors, a highly pathogenic hybrid of EAEC and EHEC emerged as the current outbreak clone. In conclusion, rapid next-generation technologies facilitated prospective whole genome characterization in the early stages of an outbreak.

739 citations

Journal ArticleDOI
16 Nov 2012-PLOS ONE
TL;DR: C. sakazakii is unique in the Cronobacter genus in encoding genes enabling the utilization of exogenous sialic acid which may have clinical significance, and also suggested various degrees of divergence.
Abstract: Background Species of Cronobacter are widespread in the environment and are occasional food-borne pathogens associated with serious neonatal diseases, including bacteraemia, meningitis, and necrotising enterocolitis. The genus is composed of seven species: C. sakazakii, C. malonaticus, C. turicensis, C. dublinensis, C. muytjensii, C. universalis, and C. condimenti. Clinical cases are associated with three species, C. malonaticus, C. turicensis and, in particular, with C. sakazakii multilocus sequence type 4. Thus, it is plausible that virulence determinants have evolved in certain lineages.

109 citations

Patent
13 Jun 2012
TL;DR: In this article, genomic sequences for nine strains of Cronobacter spp. (C. sakazakii - 696, 701, 680; C. malonaticus - 507, 681, C. turicensis - 564;C. muytjensii - 530; C., dublinensis- 582; and C. genomospl - 581) are described.
Abstract: Disclosed are genomic sequences for nine strains of Cronobacter spp. (C. sakazakii - 696, 701, 680; C. malonaticus - 507, 681; C. turicensis - 564; C. muytjensii - 530; C. dublinensis - 582; C. genomospl - 581) and compositions, methods, and kits for detecting, identifying and distinguishing Cronobacter spp. strains from each other and from non-Cronobacter spp. strains. Some embodiments describe isolated nucleic acid compositions unique to certain Cronobacter strains as well as compositions that are specific to all Cronobacter spp. Primer and probe compositions and methods of use of primers and probes are also provided. Kits for identification of Cronobacter spp. are also described. Some embodiments relate to computer software methods for setting a control based threshold for analysis of PCR

6 citations

Patent
01 Jun 2012
TL;DR: In this paper, compositions, methods and kits for the specific detection of enterohemorrahagic E. coli O104:H4 from contaminated samples including clinical samples, biological samples, food samples, complex food matrices, water, beverage samples, fermentation broth samples, forensic samples, environmental samples (e.g., soil, dirt, garbage, sewage, air, or water) as well as food processing and manufacturing surfaces.
Abstract: Disclosed are compositions, methods and kits for the specific detection of enterohemorrahagic E. coli O104:H4 from contaminated samples including clinical samples, biological samples, food samples, complex food matrices, water, beverage samples, fermentation broth samples, forensic samples, environmental samples (e.g., soil, dirt, garbage, sewage, air, or water) as well as food processing and manufacturing surfaces.

3 citations

Patent
05 Mar 2013
TL;DR: In this article, compositions, assays, methods, diagnostic methods, kits and diagnostic kits for the specific and differential detection of Mycobacterium avium subsp. paratuberculosis from samples including veterinary samples, clinical samples, food samples, forensic sample, an environmental sample (e.g., soil, dirt, garbage, sewage, air, or water), including food processing and manufacturing surfaces, or a biological sample.
Abstract: Disclosed are compositions, assays, methods, diagnostic methods, kits and diagnostic kits for the specific and differential detection of Mycobacterium avium subsp. paratuberculosis from samples including veterinary samples, clinical samples, food samples, forensic sample, an environmental sample (e.g., soil, dirt, garbage, sewage, air, or water), including food processing and manufacturing surfaces, or a biological sample.

1 citations


Cited by
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Journal ArticleDOI
TL;DR: A Web-based method for MLST of 66 bacterial species based on whole-genome sequencing data that enables investigators to determine the sequence types of their isolates on the basis of WGS data.
Abstract: Accurate strain identification is essential for anyone working with bacteria. For many species, multilocus sequence typing (MLST) is considered the “gold standard” of typing, but it is traditionally performed in an expensive and time-consuming manner. As the costs of whole-genome sequencing (WGS) continue to decline, it becomes increasingly available to scientists and routine diagnostic laboratories. Currently, the cost is below that of traditional MLST. The new challenges will be how to extract the relevant information from the large amount of data so as to allow for comparison over time and between laboratories. Ideally, this information should also allow for comparison to historical data. We developed a Web-based method for MLST of 66 bacterial species based on WGS data. As input, the method uses short sequence reads from four sequencing platforms or preassembled genomes. Updates from the MLST databases are downloaded monthly, and the best-matching MLST alleles of the specified MLST scheme are found using a BLAST-based ranking method. The sequence type is then determined by the combination of alleles identified. The method was tested on preassembled genomes from 336 isolates covering 56 MLST schemes, on short sequence reads from 387 isolates covering 10 schemes, and on a small test set of short sequence reads from 29 isolates for which the sequence type had been determined by traditional methods. The method presented here enables investigators to determine the sequence types of their isolates on the basis of WGS data. This method is publicly available at www.cbs.dtu.dk/services/MLST.

1,620 citations

Journal ArticleDOI
Lin Liu1, Yinhu Li1, Siliang Li1, Ni Hu1, Yimin He1, Ray Pong1, Danni Lin1, Lihua Lu1, Maggie Law1 
TL;DR: Technologies of next-generation sequencing systems are reviewed, and first-hand data from extensive experience is summarized and analyzed to discuss the advantages and specifics associated with each sequencing system.
Abstract: With fast development and wide applications of next-generation sequencing (NGS) technologies, genomic sequence information is within reach to aid the achievement of goals to decode life mysteries, make better crops, detect pathogens, and improve life qualities. NGS systems are typically represented by SOLiD/Ion Torrent PGM from Life Sciences, Genome Analyzer/HiSeq 2000/MiSeq from Illumina, and GS FLX Titanium/GS Junior from Roche. Beijing Genomics Institute (BGI), which possesses the world's biggest sequencing capacity, has multiple NGS systems including 137 HiSeq 2000, 27 SOLiD, one Ion Torrent PGM, one MiSeq, and one 454 sequencer. We have accumulated extensive experience in sample handling, sequencing, and bioinformatics analysis. In this paper, technologies of these systems are reviewed, and first-hand data from extensive experience is summarized and analyzed to discuss the advantages and specifics associated with each sequencing system. At last, applications of NGS are summarized.

1,420 citations

Journal ArticleDOI
TL;DR: The performance of these instruments were compared by sequencing an isolate of Escherichia coli O104:H4, which caused an outbreak of food poisoning in Germany in 2011, and the MiSeq had the highest throughput per run and lowest error rates.
Abstract: Three benchtop high-throughput sequencing instruments are now available. The 454 GS Junior (Roche), MiSeq (Illumina) and Ion Torrent PGM (Life Technologies) are laser-printer sized and offer modest set-up and running costs. Each instrument can generate data required for a draft bacterial genome sequence in days, making them attractive for identifying and characterizing pathogens in the clinical setting. We compared the performance of these instruments by sequencing an isolate of Escherichia coli O104:H4, which caused an outbreak of food poisoning in Germany in 2011. The MiSeq had the highest throughput per run (1.6 Gb/run, 60 Mb/h) and lowest error rates. The 454 GS Junior generated the longest reads (up to 600 bases) and most contiguous assemblies but had the lowest throughput (70 Mb/run, 9 Mb/h). Run in 100-bp mode, the Ion Torrent PGM had the highest throughput (80–100 Mb/h). Unlike the MiSeq, the Ion Torrent PGM and 454 GS Junior both produced homopolymer-associated indel errors (1.5 and 0.38 errors per 100 bases, respectively).

1,346 citations

Journal ArticleDOI
TL;DR: A comprehensive review highlights recent advances in understanding of the intestinal pathotypes of E. coli, which carry an enormous potential to cause disease and continue to present challenges to human health.
Abstract: Although Escherichia coli can be an innocuous resident of the gastrointestinal tract, it also has the pathogenic capacity to cause significant diarrheal and extraintestinal diseases. Pathogenic variants of E. coli (pathovars or pathotypes) cause much morbidity and mortality worldwide. Consequently, pathogenic E. coli is widely studied in humans, animals, food, and the environment. While there are many common features that these pathotypes employ to colonize the intestinal mucosa and cause disease, the course, onset, and complications vary significantly. Outbreaks are common in developed and developing countries, and they sometimes have fatal consequences. Many of these pathotypes are a major public health concern as they have low infectious doses and are transmitted through ubiquitous mediums, including food and water. The seriousness of pathogenic E. coli is exemplified by dedicated national and international surveillance programs that monitor and track outbreaks; unfortunately, this surveillance is often lacking in developing countries. While not all pathotypes carry the same public health profile, they all carry an enormous potential to cause disease and continue to present challenges to human health. This comprehensive review highlights recent advances in our understanding of the intestinal pathotypes of E. coli.

1,097 citations

Journal ArticleDOI
TL;DR: In this outbreak, caused by an unusual E. coli strain, cases of the hemolytic-uremic syndrome occurred predominantly in adults, with a preponderance of cases occurring in women.
Abstract: Background We describe an outbreak of gastroenteritis and the hemolytic–uremic syndrome caused by Shiga-toxin–producing Escherichia coli in Germany in May, June, and July, 2011. The consumption of sprouts was identified as the most likely vehicle of infection. Methods We analyzed data from reports in Germany of Shiga-toxin–producing E. coli gastro enteritis and the hemolytic–uremic syndrome and clinical information on patients presenting to Hamburg University Medical Center (HUMC). An outbreak case was defined as a reported case of the hemolytic–uremic syndrome or of gastroenteritis in a patient infected by Shiga-toxin–producing E. coli, serogroup O104 or serogroup unknown, with an onset of disease during the period from May 1 through July 4, 2011, in Germany. Results A total of 3816 cases (including 54 deaths) were reported in Germany, 845 of which (22%) involved the hemolytic–uremic syndrome. The outbreak was centered in northern Germany and peaked around May 21 to 22. Most of the patients in whom the hemolytic–uremic syndrome developed were adults (88%; median age, 42 years), and women were overrepresented (68%). The estimated median incubation period was 8 days, with a median of 5 days from the onset of diarrhea to the development of the hemolytic–uremic syndrome. Among 59 patients prospectively followed at HUMC, the hemolytic–uremic syndrome developed in 12 (20%), with no significant differences according to sex or reported initial symptoms and signs. The outbreak strain was typed as an enteroaggregative Shiga-toxin–producing E. coli O104:H4, producing extended-spectrum beta-lactamase. Conclusions In this outbreak, caused by an unusual E. coli strain, cases of the hemolytic–uremic syndrome occurred predominantly in adults, with a preponderance of cases occur ring in women. The hemolytic–uremic syndrome developed in more than 20% of the identified cases.

1,067 citations