Evaluation of fecal samples from mares as a source of Rhodococcus equi for their foals by use of quantitative bacteriologic culture and colony immunoblot analyses.
Abstract: To determine whether mares are a clinically important source of Rhodococcus equi for their foals. Methods: 171 mares and 171 foals from a farm in Kentucky (evaluated during 2004 and 2005). Methods: At 4 time points (2 before and 2 after parturition), the total concentration of R equi and concentration of virulent R equi were determined in fecal specimens from mares by use of quantitative bacteriologic culture and a colony immunoblot technique, respectively. These concentrations for mares of foals that developed R equi-associated pneumonia and for mares with unaffected foals were compared. Data for each year were analyzed separately. Results: R equi-associated pneumonia developed in 53 of 171 (31%) foals. Fecal shedding of virulent R equi was detected in at least 1 time point for every mare; bacteriologic culture results were positive for 62 of 171 (36%) mares at all time points. However, compared with dams of unaffected foals, fecal concentrations of total or virulent R equi in dams of foals with R equi-associated pneumonia were not significantly different. Conclusions: Results indicate that dams of foals with R equi-associated pneumonia did not shed more R equi in feces than dams of unaffected foals; therefore, R equi infection in foals was not associated with comparatively greater fecal shedding by their dams. However, detection of virulent R equi in the feces of all mares during at least 1 time point suggests that mares can be an important source of R equi for the surrounding environment.
Publication Date: 2007-01-04 PubMed ID: 17199420DOI: 10.2460/ajvr.68.1.63Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research examines whether mares act as a significant source of Rhodococcus equi, bacteria that causes pneumonia in foals. It discovers that there’s no significant difference in the shedding of R. equi between mares with foals suffering from pneumonia and those with healthy foals, implying that mares are not a significant source of the bacteria for their foals.
Methodology
- The study included 171 mares and their 171 foals from a farm in Kentucky and was conducted during 2004 and 2005.
- At four specific times (two before and two after parturition), fecal specimens from the mares were examined.
- The evaluation involved finding the total concentration of R equi and the concentration of virulent R equi by use of quantitative bacteriologic culture and a colony immunoblot technique, respectively.
- The concentration findings from mares of foals that developed R equi-associated pneumonia were compared with those of mares with unaffected foals.
- Data analysis was performed separately for each year.
Results
- R equi-associated pneumonia developed in 53 of 171 (31%) foals, indicating the prevalence of the condition.
- At least one point of fecal shedding of virulent R equi was detected in every mare, with positive bacteriologic culture results for 62 of 171 (36%) mares at all time points.
- Contrary to expectations, there was no significant difference in the fecal concentrations of total or virulent R equi in dams of foals with R equi-associated pneumonia compared to dams of unaffected foals.
Conclusions
- The results suggest that mares do not significantly contribute to the R equi infection in foals via fecal matter, as there was no comparative increase in R equi shedding in dams of infected foals versus those of healthy foals.
- However, the study found that all mares, at some point, had virulent R equi in their feces. This finding suggests that mares could potentially contribute to the environmental burden of R equi, affecting the surrounding environment rather than directly infecting their foals.
Cite This Article
APA
Grimm MB, Cohen ND, Slovis NM, Mundy GD, Harrington JR, Libal MC, Takai S, Martens RJ.
(2007).
Evaluation of fecal samples from mares as a source of Rhodococcus equi for their foals by use of quantitative bacteriologic culture and colony immunoblot analyses.
Am J Vet Res, 68(1), 63-71.
https://doi.org/10.2460/ajvr.68.1.63 Publication
Researcher Affiliations
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
MeSH Terms
- Actinomycetales Infections / microbiology
- Actinomycetales Infections / transmission
- Actinomycetales Infections / veterinary
- Animals
- Animals, Newborn
- Colony Count, Microbial / veterinary
- Feces / microbiology
- Female
- Horse Diseases / microbiology
- Horse Diseases / transmission
- Horses
- Immunoblotting / veterinary
- Infectious Disease Transmission, Vertical
- Pneumonia, Bacterial / microbiology
- Pneumonia, Bacterial / veterinary
- Pregnancy
- Rhodococcus equi / growth & development
- Rhodococcus equi / pathogenicity
- Statistics, Nonparametric
- Virulence
Citations
This article has been cited 13 times.- Cohen ND, Kahn SK, Bordin AI, Gonzales GM, da Silveira BP, Bray JM, Legere RM, Ramirez-Cortez SC. Association of pneumonia with concentrations of virulent Rhodococcus equi in fecal swabs of foals before and after intrabronchial infection with virulent R. equi. J Vet Intern Med 2022 May;36(3):1139-1145.
- Álvarez-Narváez S, Berghaus LJ, Morris ERA, Willingham-Lane JM, Slovis NM, Giguere S, Cohen ND. A Common Practice of Widespread Antimicrobial Use in Horse Production Promotes Multi-Drug Resistance. Sci Rep 2020 Jan 22;10(1):911.
- Shaw SD, Cohen ND, Chaffin MK, Blodgett GP, Syndergaard M, Hurych D. Estimating the Sensitivity and Specificity of Real-Time Quantitative PCR of Fecal Samples for Diagnosis of Rhodococcus equi Pneumonia in Foals. J Vet Intern Med 2015 Nov-Dec;29(6):1712-7.
- Whitfield-Cargile CM, Cohen ND, Suchodolski J, Chaffin MK, McQueen CM, Arnold CE, Dowd SE, Blodgett GP. Composition and Diversity of the Fecal Microbiome and Inferred Fecal Metagenome Does Not Predict Subsequent Pneumonia Caused by Rhodococcus equi in Foals. PLoS One 2015;10(8):e0136586.
- Bordin AI, Pillai SD, Brake C, Bagley KB, Bourquin JR, Coleman M, Oliveira FN, Mwangi W, McMurray DN, Love CC, Felippe MJ, Cohen ND. Immunogenicity of an electron beam inactivated Rhodococcus equi vaccine in neonatal foals. PLoS One 2014;9(8):e105367.
- Kachroo P, Ivanov I, Seabury AG, Liu M, Chowdhary BP, Cohen ND. Age-related changes following in vitro stimulation with Rhodococcus equi of peripheral blood leukocytes from neonatal foals. PLoS One 2013;8(5):e62879.
- Mohn WW, Wilbrink MH, Casabon I, Stewart GR, Liu J, van der Geize R, Eltis LD. Gene cluster encoding cholate catabolism in Rhodococcus spp. J Bacteriol 2012 Dec;194(24):6712-9.
- Kuskie KR, Smith JL, Wang N, Carter CN, Chaffin MK, Slovis NM, Stepusin RS, Cattoi AE, Takai S, Cohen ND. Effects of location for collection of air samples on a farm and time of day of sample collection on airborne concentrations of virulent Rhodococcus equi at two horse breeding farms. Am J Vet Res 2011 Jan;72(1):73-9.
- Summer EJ, Liu M, Gill JJ, Grant M, Chan-Cortes TN, Ferguson L, Janes C, Lange K, Bertoli M, Moore C, Orchard RC, Cohen ND, Young R. Genomic and functional analyses of Rhodococcus equi phages ReqiPepy6, ReqiPoco6, ReqiPine5, and ReqiDocB7. Appl Environ Microbiol 2011 Jan;77(2):669-83.
- Gadkowski LB, Stout JE. Cavitary pulmonary disease. Clin Microbiol Rev 2008 Apr;21(2):305-33, table of contents.
- da Silveira BP, Kahn SK, Legere RM, Bray JM, Cole-Pfeiffer HM, Golding MC, Cohen ND, Bordin AI. Enteral immunization with live bacteria reprograms innate immune cells and protects neonatal foals from pneumonia. Sci Rep 2025 May 25;15(1):18156.
- Kabir A, Lamichhane B, Habib T, Adams A, El-Sheikh Ali H, Slovis NM, Troedsson MHT, Helmy YA. Antimicrobial Resistance in Equines: A Growing Threat to Horse Health and Beyond-A Comprehensive Review. Antibiotics (Basel) 2024 Jul 29;13(8).
- Higgins C, Cohen ND, Slovis N, Boersma M, Gaonkar PP, Golden DR, Huber L. Antimicrobial Residue Accumulation Contributes to Higher Levels of Rhodococcus equi Carrying Resistance Genes in the Environment of Horse-Breeding Farms. Vet Sci 2024 Feb 17;11(2).
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
