Virulence Gene Profiling ofPasteurella multocidaIsolated from Oedema Fluid of a Buffalo

Strains ofEscherichia coliO26:H11 that were positive forstx2alone (n= 23), which were not epidemiologically related or part of an outbreak, were isolated from pediatric patients in France between 2010 and 2013. We were interested in comparing these strains with the new highly virulentstx2a-positiveE. coliO26 clone sequence type 29 (ST29) that has emerged recently in Europe, and we tested them by multilocus sequence typing (MLST),stx2subtyping, clustered regularly interspaced short palindromic repeat (CRISPR) sequencing, and plasmid (ehxA,katP,espP, andetpD) and chromosomal (Z2098,espK, andespV) virulence gene profiling. We showed that 16 of the 23 strains appeared to correspond to this new clone, but the characteristics of 12 strains differed significantly from the previously described characteristics, with negative results for both plasmid and chromosomal genetic markers. These 12 strains exhibited a ST29 genotype and related CRISPR arrays (CRISPR2a alleles 67 or 71), suggesting that they evolved in a common environment. This finding was corroborated by the presence ofstx2din 7 of the 12 ST29 strains. This is the first time thatE. coliO26:H11 carryingstx2dhas been isolated from humans. This is additional evidence of the continuing evolution of virulent Shiga toxin-producingE. coli(STEC) O26 strains. A new O26:H11 CRISPR PCR assay, SP_O26_E, has been developed for detection of these 12 particular ST29 strains ofE. coliO26:H11. This test is useful to better characterize thestx2-positive O26:H11 clinical isolates, which are associated with severe clinical outcomes such as bloody diarrhea and hemolytic uremic syndrome.

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Virulence gene profiling and ompA sequence analysis of Pasteurella multocida and their correlation with host species

Veterinary Microbiology ◽

10.1016/j.vetmic.2019.05.005 ◽

2019 ◽

Vol 233 ◽

pp. 190-195 ◽

Cited By ~ 3

Author(s):

B. Ujvári ◽

L. Makrai ◽

T. Magyar

Keyword(s):

Sequence Analysis ◽

Host Species ◽

Pasteurella Multocida ◽

Virulence Gene ◽

Gene Profiling

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Virulence genotypes of clinical SalmonellaSerovars from broilers in Egypt

The Journal of Infection in Developing Countries ◽

10.3855/jidc.7437 ◽

2016 ◽

Vol 10 (04) ◽

pp. 337-346 ◽

Cited By ~ 9

Author(s):

Ahmed Mohamed Ammar ◽

Adel Attia Mohamed ◽

Marwa Ibrahim Abd El-Hamid ◽

Mona Mohamed El-Azzouny

Keyword(s):

Antibiotic Resistance ◽

Foodborne Pathogens ◽

Broiler Chickens ◽

Virulence Gene ◽

Distribution Patterns ◽

Gene Profiling ◽

Virulence Determinants ◽

Resistance Patterns ◽

Microbiological Techniques ◽

Salmonella Serovars

Introduction: Salmonella serovars are one of the primary foodborne pathogens. Poultry consumption is responsible for the majority of disease cases worldwide. The prevalence of virulence determinants among Salmonella serovars appears to be lacking in Egypt. Therefore, this study investigated the occurrence, antibiotic resistance patterns, and virulence gene profiling of Salmonella serovars in broilers. Methodology: Three hundred samples from broiler chickens were examined for the presence of Salmonella by standard microbiological techniques. All Salmonella isolates were tested for their sensitivity against ten antibiotics and subjected to virulence genotyping by polymerase chain reaction (PCR). Results: The overall isolation percentage of Salmonella was 17%. Seven different serovars were found, with the main one being Salmonella Typhimurium (52.94%). Salmonella isolates were sensitive to most of the tested antibiotics, but they exhibited absolute resistance against amoxicillin/clavulanic acid. Nine Salmonella strains (52.94%) were resistant to at least three antibiotics. Further PCR investigations into 17 Salmonella strains revealed different distribution patterns of eight virulence determinants among the isolates. The invA gene was the most prevalent one (100%), followed by hilA (88.24%), stn (58.82%), and fliC genes (52.94%), while each of sopB and pefA genes had a similar prevalence (41.18%), and sefC and spvC genes had the lowest prevalence (11.76 and 5.88%, respectively). PCR genotyping allowed grouping of Salmonella strains into ten genetic profiles. Conclusions: These results will help in understanding the spread of virulence genotypes and antibiotic resistance among Salmonella serovars in broilers.

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Molecular Characterization of a Serotype O121:H19 Clone, a Distinct Shiga Toxin-Producing Clone of Pathogenic Escherichia coli

Infection and Immunity ◽

10.1128/iai.70.12.6853-6859.2002 ◽

2002 ◽

Vol 70 (12) ◽

pp. 6853-6859 ◽

Cited By ~ 52

Author(s):

Cheryl L. Tarr ◽

Teresa M. Large ◽

Chris L. Moeller ◽

David W. Lacher ◽

Phillip I. Tarr ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Allelic Variation ◽

Virulence Gene ◽

Gene Profiling ◽

Enzyme Electrophoresis ◽

Sequencing Analysis ◽

Chromosomal Dna ◽

Waterborne Outbreak ◽

E Coli

ABSTRACT Most illnesses caused by Shiga toxin-producing Escherichia coli (STEC) have been attributed to E. coli serotype O157:H7, but non-O157 STEC infections are now increasingly recognized as public health problems worldwide. The O121:H19 serotype is being isolated more frequently from clinical specimens and has been implicated in one waterborne outbreak. We used multilocus virulence gene profiling, a PCR-based assay, to characterize the virulence gene content of 24 isolates of serotype O121:H19 and nonmotile variants. We also performed multilocus enzyme electrophoresis and multilocus sequencing to establish the clonal relatedness of O121 isolates and to elucidate the relationship of O121 to common STEC clones. The 24 isolates were found to represent a single bacterial clone, as there was no allelic variation across 18 enzyme loci among the isolates. The complete nucleotide sequence of the intimin gene differed by four substitutions from that of the epsilon (Int-ε) allele of O103:H2 strain PMK5. The typical O121 virulence gene profile was similar to the profiles of enterohemorrhagic E. coli (EHEC) clones of E. coli: it included a Shiga toxin 2 gene (stx 2), two genes on the EHEC plasmid (toxB and ehxA), and the gene encoding intimin (eae). Despite the similarities, putative virulence genes distributed on O islands—large chromosomal DNA segments present in the O157:H7 genome—were useful for discriminating among STEC serotypes and the O121:H19 clone had a composite profile that was distinct from the profiles of the other major EHEC clones of pathogenic E. coli. On the basis of sequencing analysis with 13 housekeeping genes, the O121:H19 clone did not fall into any of the four classical EHEC and enteropathogenic E. coli groups but instead was closely related to two eae-negative STEC strains.

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Prevalence and virulence gene profiling of enteroaggregative Escherichia coli in malnourished and nourished Brazilian children

Diagnostic Microbiology and Infectious Disease ◽

10.1016/j.diagmicrobio.2017.06.024 ◽

2017 ◽

Vol 89 (2) ◽

pp. 98-105 ◽

Cited By ~ 11

Author(s):

Alexandre Havt ◽

Ila FN Lima ◽

Pedro HQS Medeiros ◽

Marco AF Clementino ◽

Ana KS Santos ◽

...

Keyword(s):

Escherichia Coli ◽

Virulence Gene ◽

Gene Profiling ◽

Brazilian Children

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Navigating Microbiological Food Safety in the Era of Whole-Genome Sequencing

Clinical Microbiology Reviews ◽

10.1128/cmr.00056-16 ◽

2016 ◽

Vol 29 (4) ◽

pp. 837-857 ◽

Cited By ~ 75

Author(s):

J. Ronholm ◽

Neda Nasheri ◽

Nicholas Petronella ◽

Franco Pagotto

Keyword(s):

Food Safety ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Antibiotic Resistance Gene ◽

Virulence Gene ◽

Complete Information ◽

Gene Profiling ◽

Whole Genome Sequence ◽

Whole Genome ◽

Molecular Subtyping

SUMMARYThe epidemiological investigation of a foodborne outbreak, including identification of related cases, source attribution, and development of intervention strategies, relies heavily on the ability to subtype the etiological agent at a high enough resolution to differentiate related from nonrelated cases. Historically, several different molecular subtyping methods have been used for this purpose; however, emerging techniques, such as single nucleotide polymorphism (SNP)-based techniques, that use whole-genome sequencing (WGS) offer a resolution that was previously not possible. With WGS, unlike traditional subtyping methods that lack complete information, data can be used to elucidate phylogenetic relationships and disease-causing lineages can be tracked and monitored over time. The subtyping resolution and evolutionary context provided by WGS data allow investigators to connect related illnesses that would be missed by traditional techniques. The added advantage of data generated by WGS is that these data can also be used for secondary analyses, such as virulence gene detection, antibiotic resistance gene profiling, synteny comparisons, mobile genetic element identification, and geographic attribution. In addition, several software packages are now available to generatein silicoresults for traditional molecular subtyping methods from the whole-genome sequence, allowing for efficient comparison with historical databases. Metagenomic approaches using next-generation sequencing have also been successful in the detection of nonculturable foodborne pathogens. This review addresses state-of-the-art techniques in microbial WGS and analysis and then discusses how this technology can be used to help support food safety investigations. Retrospective outbreak investigations using WGS are presented to provide organism-specific examples of the benefits, and challenges, associated with WGS in comparison to traditional molecular subtyping techniques.

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