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First study of pathogen load and localisation of ovine footrot using fluorescence in situ hybridisation (FISH).

Witcomb LA, Green LE, Calvo-Bado LA, Russell CL, Smith EM, Grogono-Thomas R, Wellington EM - Vet. Microbiol. (2015)

Bottom Line: D. nodosus and F. necrophorum populations were restricted primarily to the epidermis, but both were detected more frequently in feet with ID or SFR than in healthy feet.D. nodosus cell counts were significantly higher in feet with ID and SFR (p<0.05) than healthy feet, whereas F. necrophorum cell counts were significantly higher only in feet with SFR (p<0.05) than healthy feet.In contrast, F. necrophorum cell counts increase after SFR onset, which may suggest an accessory role in disease pathogenesis, possibly contributing to the severity and duration of SFR.

View Article: PubMed Central - PubMed

Affiliation: School of Life Sciences, University of Warwick, Gibbet Hill Campus, Coventry, UK; UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, UK. Electronic address: l.witcomb@ucl.ac.uk.

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Tissue morphology of biopsy sections by disease state (healthy, ID and SFR) (A), and evidence of sloughing of necrotic tissue carrying bacterial cells (B). Bacterial cells (red), epithelial cells (green), epithelial cell nuclei (blue) and erythrocytes (white – autofluorescence). Stratum corneum (SC), partial stratum corneum (pSC), stratum spinosum (SS) and extracellular milieu (EM) are shown (red channel images removed from (A) for tissue morphology to be observed). Scale bars: 25 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
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fig0015: Tissue morphology of biopsy sections by disease state (healthy, ID and SFR) (A), and evidence of sloughing of necrotic tissue carrying bacterial cells (B). Bacterial cells (red), epithelial cells (green), epithelial cell nuclei (blue) and erythrocytes (white – autofluorescence). Stratum corneum (SC), partial stratum corneum (pSC), stratum spinosum (SS) and extracellular milieu (EM) are shown (red channel images removed from (A) for tissue morphology to be observed). Scale bars: 25 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Mentions: For healthy feet, 1/12 and 6/12 swabs were positive for F. necrophorum (rpoB) and D. nodosus (rpoD), respectively. Samples that were positive were on the limit of detection (∼103 copies swab−1), which is consistent with earlier findings (Calvo-Bado et al., 2011; Witcomb et al., 2014). A total of 5/6 and 6/6 swabs from ID feet were positive for F. necrophorum (rpoB) and D. nodosus (rpoD), respectively. Similarly, 100% of swabs were positive for both bacterial species from feet with SFR. Significant necrosis of the stratum corneum was present in tissue from feet with ID and SFR and bacterial cells were observed in the sloughed necrotic tissue, sometimes in large numbers (Fig. 1). In addition, the infiltration of erythrocytes was associated with both stages of disease and absent in healthy feet (Fig. 2). Erythrocytes appeared as auto-fluorescent cells under all three channels.


First study of pathogen load and localisation of ovine footrot using fluorescence in situ hybridisation (FISH).

Witcomb LA, Green LE, Calvo-Bado LA, Russell CL, Smith EM, Grogono-Thomas R, Wellington EM - Vet. Microbiol. (2015)

Tissue morphology of biopsy sections by disease state (healthy, ID and SFR) (A), and evidence of sloughing of necrotic tissue carrying bacterial cells (B). Bacterial cells (red), epithelial cells (green), epithelial cell nuclei (blue) and erythrocytes (white – autofluorescence). Stratum corneum (SC), partial stratum corneum (pSC), stratum spinosum (SS) and extracellular milieu (EM) are shown (red channel images removed from (A) for tissue morphology to be observed). Scale bars: 25 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4366039&req=5

fig0015: Tissue morphology of biopsy sections by disease state (healthy, ID and SFR) (A), and evidence of sloughing of necrotic tissue carrying bacterial cells (B). Bacterial cells (red), epithelial cells (green), epithelial cell nuclei (blue) and erythrocytes (white – autofluorescence). Stratum corneum (SC), partial stratum corneum (pSC), stratum spinosum (SS) and extracellular milieu (EM) are shown (red channel images removed from (A) for tissue morphology to be observed). Scale bars: 25 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
Mentions: For healthy feet, 1/12 and 6/12 swabs were positive for F. necrophorum (rpoB) and D. nodosus (rpoD), respectively. Samples that were positive were on the limit of detection (∼103 copies swab−1), which is consistent with earlier findings (Calvo-Bado et al., 2011; Witcomb et al., 2014). A total of 5/6 and 6/6 swabs from ID feet were positive for F. necrophorum (rpoB) and D. nodosus (rpoD), respectively. Similarly, 100% of swabs were positive for both bacterial species from feet with SFR. Significant necrosis of the stratum corneum was present in tissue from feet with ID and SFR and bacterial cells were observed in the sloughed necrotic tissue, sometimes in large numbers (Fig. 1). In addition, the infiltration of erythrocytes was associated with both stages of disease and absent in healthy feet (Fig. 2). Erythrocytes appeared as auto-fluorescent cells under all three channels.

Bottom Line: D. nodosus and F. necrophorum populations were restricted primarily to the epidermis, but both were detected more frequently in feet with ID or SFR than in healthy feet.D. nodosus cell counts were significantly higher in feet with ID and SFR (p<0.05) than healthy feet, whereas F. necrophorum cell counts were significantly higher only in feet with SFR (p<0.05) than healthy feet.In contrast, F. necrophorum cell counts increase after SFR onset, which may suggest an accessory role in disease pathogenesis, possibly contributing to the severity and duration of SFR.

View Article: PubMed Central - PubMed

Affiliation: School of Life Sciences, University of Warwick, Gibbet Hill Campus, Coventry, UK; UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, UK. Electronic address: l.witcomb@ucl.ac.uk.

Show MeSH
Related in: MedlinePlus