Multiple-Locus Variable-Number Tandem-Repeats Analysis of Escherichia coli O157 using PCR multiplexing and multi-colored capillary electrophoresis

ABSTRACT Field and laboratory studies were performed to determine whether slugs could act as novel vectors for pathogen (e.g., Escherichia coli O157) transfer from animal feces to salad vegetables. Escherichia coli O157 was isolated from 0.21% of field slugs from an Aberdeenshire sheep farm. These isolates carried the verocytotoxin genes (vt1 and vt2) and the attaching and effacing gene (eae), suggesting that they are potentially pathogenic to humans. Strain typing using multilocus variable number tandem repeats analysis showed that slug and sheep isolates were indistinguishable. Laboratory experiments using an E. coli mutant resistant to nalidixic acid showed that the ubiquitous slug species Deroceras reticulatum could carry viable E. coli on its external surface for up to 14 days. Slugs that had been fed E. coli shed viable bacteria in their feces with numbers showing a short but statistically significant linear log decline. Further, it was found that E. coli persisted for up to 3 weeks in excreted slug feces, and hence, we conclude that slugs have the potential to act as novel vectors of E. coli O157.

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Introduction of Infected Animals to Herds Is an Important Route for the Spread of Yersinia enterocolitica Infection between Pig Farms

Journal of Food Protection ◽

10.4315/0362-028x.jfp-13-144 ◽

2014 ◽

Vol 77 (1) ◽

pp. 116-121 ◽

Cited By ~ 7

Author(s):

S. VIRTANEN ◽

S. NIKUNEN ◽

H. KORKEALA

Keyword(s):

Yersinia Enterocolitica ◽

Tandem Repeats ◽

Variable Number ◽

Multiple Locus ◽

Pig Farms ◽

Sources Of Infection ◽

Enterocolitica Infection ◽

Variable Number Tandem Repeats ◽

Pathogenic Yersinia

Altogether, 369 pathogenic Yersinia enterocolitica isolates from 1,118 fecal samples collected from 22 pig farms of different production types were characterized by biotyping, serotyping, and genotyping using multiple-locus variable-number tandem repeats analysis. We investigated the distribution of the different genotypes at the farm level and their association with different farm conditions. Pigs were found to carry and transmit Y. enterocolitica between farms, because the same genotypes were found on farms that had previously transported the pigs between them. The purchase of new animals for the farms associated significantly with the number of different multiple-locus variable-number tandem repeats analysis types of Y. enterocolitica found within a farm. Some genotypes seemed to persist on farms for years. The results of this study show that pigs purchased from infected herds transmit Y. enterocolitica infection between farms. Certain pig farms may act as long-term sources of infection.

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Multiple-locus variable number of tandem repeat analysis (MLVA) of Irish verocytotoxigenic Escherichia coli O157 from feedlot cattle: uncovering strain dissemination routes

BMC Veterinary Research ◽

10.1186/1746-6148-4-2 ◽

2008 ◽

Vol 4 (1) ◽

pp. 2 ◽

Cited By ~ 12

Author(s):

Mary Murphy ◽

Donal Minihan ◽

James F Buckley ◽

Micheál O'Mahony ◽

Paul Whyte ◽

...

Keyword(s):

Escherichia Coli ◽

Tandem Repeat ◽

Variable Number ◽

Feedlot Cattle ◽

Escherichia Coli O157 ◽

Multiple Locus ◽

Repeat Analysis

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Effects of Environmental Stress on Stability of Tandem Repeats in Escherichia coli O157:H7

Applied and Environmental Microbiology ◽

10.1128/aem.02373-09 ◽

2010 ◽

Vol 76 (10) ◽

pp. 3398-3400 ◽

Cited By ~ 20

Author(s):

Michael B. Cooley ◽

Diana Carychao ◽

Kimberly Nguyen ◽

Linda Whitehand ◽

Robert Mandrell

Keyword(s):

Escherichia Coli ◽

Phylogenetic Diversity ◽

Tandem Repeats ◽

Elevated Temperatures ◽

Variable Number Tandem Repeat ◽

Variable Number ◽

Source Tracking ◽

Escherichia Coli O157 ◽

Repeat Analysis ◽

Starvation Conditions

ABSTRACT Multilocus variable-number tandem-repeat analysis (MLVA) is used for source tracking Escherichia coli O157:H7 in agricultural environments. Tandem repeats were stable after limited replication but changed after exposure to irradiation, elevated temperatures, and starvation conditions. The pO157 plasmid was frequently lost under these stress conditions. Environmental stresses may increase phylogenetic diversity as measured by MLVA.

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Development of Multiple-Locus Variable-Number Tandem-Repeat Analysis for the Molecular Subtyping of Enterobacter sakazakii

Applied and Environmental Microbiology ◽

10.1128/aem.01726-07 ◽

2007 ◽

Vol 74 (4) ◽

pp. 1223-1231 ◽

Cited By ~ 25

Author(s):

N. R. Mullane ◽

M. Ryan ◽

C. Iversen ◽

M. Murphy ◽

P. O'Gaora ◽

...

Keyword(s):

Tandem Repeats ◽

Fluorescent Dyes ◽

Variable Number Tandem Repeat ◽

Variable Number ◽

Enterobacter Sakazakii ◽

Multiple Locus ◽

Epidemiological Tool ◽

Genescan Analysis ◽

Variable Number Tandem Repeats ◽

Multiple Locus Vntr Analysis

ABSTRACT The genomic content of Enterobacter sakazakii strain ATCC BAA-894 was analyzed for variable-number tandem repeats (VNTRs). In this study we report the development of a multiple-locus VNTR analysis (MLVA) strategy for the subtyping of E. sakazakii. The method is based on a GeneScan analysis of four VNTR loci labeled with multiple fluorescent dyes. This approach was applied to a collection of 112 isolates representing all 16 of the currently defined E. sakazakii biogroups. MLVA successfully discriminated among these isolates and compared favorably with pulsed-field gel electrophoresis. The method was relatively fast and easy to perform. The potential value of MLVA as an epidemiological tool is discussed.

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Análise genotípica do Helicobacter pylori pelo método Multiple-Locus Variable-Number Tandem-Repeats no sul do Brasil

Revista de Epidemiologia e Controle de Infecção ◽

10.17058/reci.v6i4.8043 ◽

2016 ◽

Vol 6 (4) ◽

Author(s):

Priscila Cristina Bartolomeu Halicki ◽

Ivy Bastos Ramis ◽

Júlia Silveira Vianna ◽

Thaísa Bozzetti Gautério ◽

Andrea von Groll ◽

...

Keyword(s):

Helicobacter Pylori ◽

In Silico ◽

Tandem Repeats ◽

Variable Number ◽

Multiple Locus ◽

H Pylori ◽

Variable Number Tandem Repeats

Justificativa e objetivos: Apesar de ser utilizado como um método de genotipagem para diferentes microrganismos, poucos estudos relatam a utilização de Multiple-Locus Variable Number of Tandem Repeats Analysis (MLVA) para análise da diversidade clonal do Helicobacter pylori. O objetivo deste estudo foi determinar a variabilidade genética de cepas de H. pylori pelo MLVA no sul do Brasil. Métodos: 95 amostras de DNA de H. pylori foram obtidas a partir de biópsias gástricas de pacientes H. pylori-positivos provenientes de duas cidades do sul do Brasil e a diversidade genética das cepas foi avaliada pelo método MLVA utilizando eletroforese em gel de agarose. Para a seleção dos loci a serem analisados neste estudo, foi realizada uma análise in silico de 12 loci previamente descritos na literatura. Resultados: A partir da análise in silico, apenas quatro loci foram considerados viáveis para a análise genotípica das cepas, resultando em 90 cepas distribuídas em oito grupos diferentes e cinco cepas órfãs. Conclusões: Apesar de o método MLVA permitir fazer inferências acerca da diversidade genética de uma população, nossos resultados mostraram que os métodos de genotipagem do H. pylori devem ser criticamente avaliados antes de serem utilizados nessa região do Brasil.

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