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The variability and seasonality of the environmental reservoir of Mycobacterium bovis shed by wild European badgers.

King HC, Murphy A, James P, Travis E, Porter D, Hung YJ, Sawyer J, Cork J, Delahay RJ, Gaze W, Courtenay O, Wellington EM - Sci Rep (2015)

Bottom Line: The incidence of Mycobacterium bovis, the causative agent of bovine tuberculosis, has been increasing in UK cattle herds resulting in substantial economic losses.The European badger (Meles meles) is implicated as a wildlife reservoir of infection.Here we identify potential infection hotspots in the badger population and quantify the heterogeneity in bacterial load; with infected badgers shedding between 1 × 10(3)- 4 × 10(5) M. bovis cells g(-1) of faeces, creating a substantial and seasonally variable environmental reservoir.

View Article: PubMed Central - PubMed

Affiliation: University of Warwick, School of Life Sciences, Gibbet Hill Campus, Coventry, CV4 7AL.

ABSTRACT
The incidence of Mycobacterium bovis, the causative agent of bovine tuberculosis, has been increasing in UK cattle herds resulting in substantial economic losses. The European badger (Meles meles) is implicated as a wildlife reservoir of infection. One likely route of transmission to cattle is through exposure to infected badger urine and faeces. The relative importance of the environment in transmission remains unknown, in part due to the lack of information on the distribution and magnitude of environmental reservoirs. Here we identify potential infection hotspots in the badger population and quantify the heterogeneity in bacterial load; with infected badgers shedding between 1 × 10(3)- 4 × 10(5) M. bovis cells g(-1) of faeces, creating a substantial and seasonally variable environmental reservoir. Our findings highlight the potential importance of monitoring environmental reservoirs of M. bovis which may constitute a component of disease spread that is currently overlooked and yet may be responsible for a proportion of transmission amongst badgers and onwards to cattle.

No MeSH data available.


Related in: MedlinePlus

The cumulative M. bovis genome equivalents shed by each social group per season.Created in R version 3.0.2 using the packages ggplots 231 and ggmaps32. The scales for all graphs are identical.
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f4: The cumulative M. bovis genome equivalents shed by each social group per season.Created in R version 3.0.2 using the packages ggplots 231 and ggmaps32. The scales for all graphs are identical.

Mentions: Overall a significantly greater number of M. bovis genome equivalents were shed in summer than in any other season. There were substantial seasonal differences in the cumulative number of M. bovis equivalents detected per social group (Fig. 4) with different groups identified as the largest contributors to the environmental pool of M. bovis throughout the year. Although summer had the highest number of genome equivalents overall, Septic Tank shed fewer cells in summer compared to other seasons and Top and shed more cells in spring. Nettle also shed fewer M. bovis genome equivalents in spring compared with the rest of the year. However, five social groups (Nettle, West, Honeywell, Septic Tank, and Top) were identified as having consistently high proportions of positive faeces and relatively large quantities of M. bovis bacilli shed (Table 1). This corresponds to immunoassay tests carried out on trapped badgers, which also identified these five groups as the most heavily infected (Table 1). Although there is strong correspondence between immunoassay and qPCR results there are some discrepancies, in particular Nettle and Top are 100% and 90% positive by immunoassay yet there was a large difference in the percentage of positive faecal samples with 42.2% and 10.0% respectively.


The variability and seasonality of the environmental reservoir of Mycobacterium bovis shed by wild European badgers.

King HC, Murphy A, James P, Travis E, Porter D, Hung YJ, Sawyer J, Cork J, Delahay RJ, Gaze W, Courtenay O, Wellington EM - Sci Rep (2015)

The cumulative M. bovis genome equivalents shed by each social group per season.Created in R version 3.0.2 using the packages ggplots 231 and ggmaps32. The scales for all graphs are identical.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4527091&req=5

f4: The cumulative M. bovis genome equivalents shed by each social group per season.Created in R version 3.0.2 using the packages ggplots 231 and ggmaps32. The scales for all graphs are identical.
Mentions: Overall a significantly greater number of M. bovis genome equivalents were shed in summer than in any other season. There were substantial seasonal differences in the cumulative number of M. bovis equivalents detected per social group (Fig. 4) with different groups identified as the largest contributors to the environmental pool of M. bovis throughout the year. Although summer had the highest number of genome equivalents overall, Septic Tank shed fewer cells in summer compared to other seasons and Top and shed more cells in spring. Nettle also shed fewer M. bovis genome equivalents in spring compared with the rest of the year. However, five social groups (Nettle, West, Honeywell, Septic Tank, and Top) were identified as having consistently high proportions of positive faeces and relatively large quantities of M. bovis bacilli shed (Table 1). This corresponds to immunoassay tests carried out on trapped badgers, which also identified these five groups as the most heavily infected (Table 1). Although there is strong correspondence between immunoassay and qPCR results there are some discrepancies, in particular Nettle and Top are 100% and 90% positive by immunoassay yet there was a large difference in the percentage of positive faecal samples with 42.2% and 10.0% respectively.

Bottom Line: The incidence of Mycobacterium bovis, the causative agent of bovine tuberculosis, has been increasing in UK cattle herds resulting in substantial economic losses.The European badger (Meles meles) is implicated as a wildlife reservoir of infection.Here we identify potential infection hotspots in the badger population and quantify the heterogeneity in bacterial load; with infected badgers shedding between 1 × 10(3)- 4 × 10(5) M. bovis cells g(-1) of faeces, creating a substantial and seasonally variable environmental reservoir.

View Article: PubMed Central - PubMed

Affiliation: University of Warwick, School of Life Sciences, Gibbet Hill Campus, Coventry, CV4 7AL.

ABSTRACT
The incidence of Mycobacterium bovis, the causative agent of bovine tuberculosis, has been increasing in UK cattle herds resulting in substantial economic losses. The European badger (Meles meles) is implicated as a wildlife reservoir of infection. One likely route of transmission to cattle is through exposure to infected badger urine and faeces. The relative importance of the environment in transmission remains unknown, in part due to the lack of information on the distribution and magnitude of environmental reservoirs. Here we identify potential infection hotspots in the badger population and quantify the heterogeneity in bacterial load; with infected badgers shedding between 1 × 10(3)- 4 × 10(5) M. bovis cells g(-1) of faeces, creating a substantial and seasonally variable environmental reservoir. Our findings highlight the potential importance of monitoring environmental reservoirs of M. bovis which may constitute a component of disease spread that is currently overlooked and yet may be responsible for a proportion of transmission amongst badgers and onwards to cattle.

No MeSH data available.


Related in: MedlinePlus