Journal article
The effect of bacterial dose and foal age at challenge on Rhodococcus equi infection
Veterinary microbiology, Vol.167(3-4), pp.623-631
12/27/2013
DOI: 10.1016/j.vetmic.2013.09.018
PMID: 24139178
Abstract
While Rhodococcus equi remains the most common cause of subacute or chronic granulomatous bronchopneumonia in foals, development of a relevant model to study R. equi infection has proven difficult. The objective of this study was to identify a challenge dose of R. equi that resulted in slow progressive disease, spontaneous regression of lung lesions and age-dependent susceptibility. Foals less than one-week of age were challenged intratracheally using either 106, 105, 104, 103 or 102cfu of R. equi. Two doses (103cfu and 105cfu) were used to challenge 2 and 3-week-old, and 3 and 6-week-old foals, respectively. Physical examination, thoracic ultrasound and blood work were performed. Foals were euthanized at the end of the study or when clinical signs of pneumonia developed. All foals were necropsied and their lung lesions scored. Foals challenged with low concentrations of R. equi developed slow progressive pneumonia and approximately 50% of the foals recovered spontaneously. Likewise, macroscopic (>1cm diameter) pyogranulomatous lesions were only observed when low doses of R. equi were used. Clinical pneumonia was not seen after low dose challenge in the 3-week-old foals or in the 6-week-old foals. This study demonstrates that the use of low doses of R. equi to challenge neonatal foals provides an improved model for studying this disease. Furthermore, susceptibility to R. equi infection was shown to diminish early in the foal's life, as has been reported in the field.
Details
- Title: Subtitle
- The effect of bacterial dose and foal age at challenge on Rhodococcus equi infection
- Creators
- M Sanz - Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546-0099, United StatesA Loynachan - Veterinary Diagnostic Laboratory, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546-0099, United StatesL Sun - Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546-0099, United StatesA Oliveira - Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546-0099, United StatesP Breheny - Department of Biostatistics, University of Kentucky, Lexington, KY 40546-0099, United StatesD.W Horohov - Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546-0099, United States
- Resource Type
- Journal article
- Publication Details
- Veterinary microbiology, Vol.167(3-4), pp.623-631
- Publisher
- Elsevier B.V
- DOI
- 10.1016/j.vetmic.2013.09.018
- PMID
- 24139178
- ISSN
- 0378-1135
- eISSN
- 1873-2542
- Grant note
- name: Bioniche Animal Health; DOI: 10.13039/100012895, name: Zoetis; name: CNPq Brazil
- Language
- English
- Date published
- 12/27/2013
- Academic Unit
- Biostatistics
- Record Identifier
- 9983997335102771
Metrics
25 Record Views