Development of a Strain-Specific Molecular Method for Quantitating Individual
            <i>Campylobacter</i>
            Strains in Mixed Populations

Elvers, Karen T; Helps, Christopher R; Wassenaar, Trudy M.; Allen, V. M.; Newell, Diane G.

doi:10.1128/aem.02269-07

Cited by 5 publications

(8 citation statements)

References 51 publications

(55 reference statements)

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“…All presumptive Campylobacter colonies were counted. One plate for each sample was then precooled at 4°C, and colony lifts were taken as described previously (10). After transferring the colonies onto Hybond membranes, the plates were reincubated at 41.5°C microaerobically for 24 h in order to take a second lift, if required.…”

Section: Methodsmentioning

confidence: 99%

“…For each Campylobacter-positive flock, 5 or 6 strains colonizing each flock were selected for flaA PCR using the primers FLA4F and FLA625R (10). The PCR products were sequenced.…”

Section: Methodsmentioning

confidence: 99%

“…The PCR products were sequenced. The resulting sequences were aligned using CLC Free Workbench (CLC bio, Denmark), and strain-specific SVR probes were designed and labeled as described previously (10). A fla allele identification was ascribed by BLAST analysis in comparison with flaA sequences in the Oxford database (http://pubmlst.org/campylobacter/).…”

Section: Methodsmentioning

confidence: 99%

“…A fully colonized flock of 20,000 birds may enter the abattoir environment carrying about 10 13 CFU of Campylobacter of a single or multiple strains in their intestinal contents. These contents may spill during processing, contaminating the abattoir environment.…”

mentioning

confidence: 99%

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Molecular Tracking, through Processing, of Campylobacter Strains Colonizing Broiler Flocks

Elvers

Morris

Newell

et al. 2011

Appl Environ Microbiol

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Many of the poultry flocks produced in the United Kingdom are colonized with Campylobacter, and the intensive nature of poultry processing usually results in contaminated carcasses. In this study, a previously reported molecular oligonucleotide probe method was used to track a specific flock-colonizing strain(s) on broiler carcasses during processing in two United Kingdom commercial poultry processing plants. Five Campylobacter-positive flocks were sampled at four points along the processing line, postbleed, postpluck, prechill, and postchill, and two Campylobacter-negative flocks processed immediately after positive flocks were sampled prechill. flaA was sequenced from Campylobacter strains isolated from these flocks, and strain-specific probes were synthesized. Skin and cecal samples were plated onto selective agar to give individual colonies, which were transferred onto membranes. These were then hybridized with the strain-and genus-specific probes. For all the 5 positive flocks, there was a significant reduction in campylobacters postbleed compared to postpluck but no subsequent fall on sampling pre-and postchill, and the strain(s) predominating on the carcasses throughout processing came from the flock being processed. This indicates that strains from the abattoir environment were not a significant cause of carcass contamination in flocks with well-established campylobacter colonization. However, negative flocks that were preceded by positive flocks were contaminated by strains that did not generally originate from the predominating strains recovered from the ceca of the previous positive flocks. This suggests that the abattoir environment has a significant role in the contamination of carcasses from negative but not fully colonized flocks.

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Section: Methodsmentioning

confidence: 99%

“…For each Campylobacter-positive flock, 5 or 6 strains colonizing each flock were selected for flaA PCR using the primers FLA4F and FLA625R (10). The PCR products were sequenced.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Molecular Tracking, through Processing, of Campylobacter Strains Colonizing Broiler Flocks

Elvers

Morris

Newell

et al. 2011

Appl Environ Microbiol

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“…The colony lift protocol was performed according to Ref. [15]. Control experiments confi rmed the specifi city of the probes as shown in Table 1.…”

Section: Volunteer Study For Colonization Potentialmentioning

confidence: 99%

Virulence genes in a probioticE. oliproduct with a recorded long history of safe use

Wassenaar¹,

Zschüttig²,

Beimfohr³

et al. 2015

European Journal of Microbiology and Immunology

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The probiotic product Symbioflor2 (DSM 17252) is a bacterial concentrate of six different Escherichia coli genotypes, whose complete genome sequences are compared here, between each other as well as to other E. coli genomes. The genome sequences of Symbioflor2 E. coli components contained a number of virulence-associated genes. Their presence seems to be in conflict with a recorded history of safe use, and with the observed low frequency of adverse effects over a period of more than 6 years. The genome sequences were used to identify unique sequences for each component, for which strain-specific hybridization probes were designed. A colonization study was conducted whereby five volunteers were exposed to an exceptionally high single dose. The results showed that the probiotic E. coli could be detected for 3 months or longer in their stools, and this was in particular the case for those components containing higher numbers of virulence-associated genes. Adverse effects from this long-term colonization were absent. Thus, the presence of the identified virulence genes does not result in a pathogenic phenotype in the genetic background of these probiotic E. coli.

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Campylobacters and their bacteriophages from chicken liver: The prospect for phage biocontrol

Firlieyanti

Connerton

2016

International Journal of Food Microbiology

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Consumption of foods containing chicken liver has been associated with Campylobacter enteritis. Campylobacters can contaminate the surface of livers post-mortem but can also arise through systemic infection of colonising bacteria in live birds. The use of bacteriophage to reduce levels of Campylobacter entering the food chain is a promising intervention approach but most phages have been isolated from chicken excreta. This study examined the incidence and contamination levels of Campylobacter and their bacteriophage in UK retail chicken liver. Using enrichment procedures, 87% of 109 chicken livers were surface contaminated with Campylobacter and 83% contaminated within internal tissues. Direct plating on selective agar allowed enumeration of viable bacteria from 43% of liver samples with counts ranging from 1.8–> 3.8 log10 CFU/cm2 for surface samples, and 3.0–> 3.8 log10 CFU/g for internal tissue samples. Three C. jejuni isolates recovered from internal liver tissues were assessed for their ability to colonise the intestines and extra-intestinal organs of broiler chickens following oral infection. All isolates efficiently colonised the chicken intestines but were variable in their abilities to colonise extra-intestinal organs. One isolate, CLB104, could be recovered by enrichment from the livers and kidneys of three of seven chickens. Campylobacter isolates remained viable within fresh livers stored at 4 °C over 72 h and frozen livers stored at − 20 °C over 7 days in atmospheric oxygen, and therefore constitute a risk to human health. Only three Campylobacter-specific bacteriophages were isolated, and these exhibited a limited host range against the Camplylobacter chicken liver isolates. All were identified as group III virulent bacteriophage based on their genome size of 140 kb. The application of broad host range group II virulent phages (8 log10 PFU/g) to liver homogenates containing C. jejuni strains of diverse origin at 4 °C resulted in modest but significant reductions in the viable counts ranging from 0.2 to 0.7 log10 CFU/g.

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Development of a Strain-Specific Molecular Method for Quantitating Individual Campylobacter Strains in Mixed Populations

Cited by 5 publications

References 51 publications

Molecular Tracking, through Processing, of Campylobacter Strains Colonizing Broiler Flocks

Molecular Tracking, through Processing, of Campylobacter Strains Colonizing Broiler Flocks

Virulence genes in a probioticE. oliproduct with a recorded long history of safe use

Campylobacters and their bacteriophages from chicken liver: The prospect for phage biocontrol

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