Diarrhea-associated pathogens, lactobacilli and cellulolytic bacteria in equine feces: responses to antibiotic challenge.
Abstract: Antibiotics are important to equine medicine, but antibiotic-associated diarrhea (AAD) can lead to poor performance and even mortality. AAD is attributed to disruption of the hindgut microbiota, which permits proliferation of pathogenic microbes. The goal of this study was to evaluate the effects of common antibiotics on cellulolytic bacteria, lactobacilli, and AAD-associated pathogens in the feces of healthy horses. Fifteen horses were assigned to three treatment groups (blocked by age and sex): control (no antibiotics), trimethoprim-sulfadiazine (PO), or ceftiofur (IM). Fecal samples (n=8 per horse) were taken during dietary adaptation (3 weeks), antibiotic challenge (1 week), and withdrawal (1 week). Bacteria were enumerated by serial dilution and viable count. Cellulolytic bacteria decreased by >99% during administration of either antibiotic (P<0.0001) and were still less than controls at the end of the withdrawal period (P<0.0001). Fecal samples from horses challenged with ceftiofur had 75% fewer lactobacilli than those from control horses at the end of the antibiotic challenge period (P<0.05). Antibiotic challenged horses also shed more salmonella than control horses (P<0.05). Antibiotics had no effect on the number of Clostridium perfringens isolates. There was no detectable Clostridium difficile during adaptation or in any control horse. C. difficile increased (P<0.0001) to approximately 10(4)cfu/g when horses were challenged with antibiotics, and were still detectable 1 week after withdrawal. These results indicate that antibiotics can disrupt the normal gastrointestinal microbiota and allow proliferation of Salmonella spp. and C. difficile.
Published by Elsevier B.V.
Publication Date: 2013-05-20 PubMed ID: 23769300DOI: 10.1016/j.vetmic.2013.05.003Google 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
- Research Support
- U.S. Gov't
- Non-P.H.S.
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.
This study investigates how common antibiotics affect certain gut bacteria in healthy horses, specifically, cellulolytic bacteria, lactobacilli, and diarrhea-associated pathogens. The findings suggest that such antibiotics can disrupt gut bacteria resulting in an increase in harmful microbes such as Salmonella and Clostridium difficile.
Methodology
- The study enrolled fifteen horses grouped into three treatment groups according to their age and sex. The groups included a control group (no antibiotics), a group administered trimethoprim-sulfadiazine orally (PO), and a group given ceftiofur via intramuscular injection (IM).
- During three stages (diet adaptation for three weeks, antibiotic treatment for a week, and withdrawal for a week), fecal samples were taken from each horse eight times. Bacteria in these samples were evaluated using serial dilution and viable count.
Findings
- The study found a significant reduction (>99%) in cellulolytic bacteria in horses during administration of either antibiotic. This reduction persisted even at the end of the withdrawal period.
- Horses treated with ceftiofur showed a 75% decrease in lactobacilli in their fecal samples compared to the control group at the end of the antibiotic treatment stage.
- There was an increase in the development and shedding of salmonella in horses treated with antibiotics compared to those in the control group.
- Interestingly, antibiotic treatment didn’t affect the number of Clostridium perfringens isolates.
- Clostridium difficile was not detectable in the horses during the adaptation stage or in the control group. However, C. difficile count increased significantly in the horses treated with antibiotics and remained detectable even a week after the withdrawal.
Conclusion
These results underscore that commonly used antibiotics may significantly disrupt the normal population of beneficial gut microbiota in horses. This microbial imbalance can promote the proliferation of pathogenic microbes such as Salmonella spp. and Clostridium difficile, potentially leading to antibiotic-associated diarrhea.
Cite This Article
APA
Harlow BE, Lawrence LM, Flythe MD.
(2013).
Diarrhea-associated pathogens, lactobacilli and cellulolytic bacteria in equine feces: responses to antibiotic challenge.
Vet Microbiol, 166(1-2), 225-232.
https://doi.org/10.1016/j.vetmic.2013.05.003 Publication
Researcher Affiliations
- University of Kentucky, Department of Animal and Food Sciences, Lexington, KY 40546, USA.
MeSH Terms
- Animals
- Anti-Bacterial Agents / pharmacology
- Bacteria / drug effects
- Bacteria / metabolism
- Bacterial Infections / microbiology
- Bacterial Infections / veterinary
- Cellulose / metabolism
- Diarrhea / microbiology
- Diarrhea / veterinary
- Feces / microbiology
- Female
- Horse Diseases / microbiology
- Horses
- Lactobacillus / drug effects
- Lactobacillus / metabolism
- Male
- Microbial Sensitivity Tests
Citations
This article has been cited 30 times.- Lai Y, Deng H, Fang Q, Ma L, Lei H, Guo X, Chen Y, Song C. Water-Insoluble Polysaccharide Extracted from Poria cocos Alleviates Antibiotic-Associated Diarrhea Based on Regulating the Gut Microbiota in Mice. Foods 2023 Aug 16;12(16).
- Muniyappan M, Shanmugam S, Park JH, Han K, Kim IH. Effects of fermented soybean meal supplementation on the growth performance and apparent total tract digestibility by modulating the gut microbiome of weaned piglets. Sci Rep 2023 Mar 6;13(1):3691.
- Wunderlich G, Bull M, Ross T, Rose M, Chapman B. Understanding the microbial fibre degrading communities & processes in the equine gut. Anim Microbiome 2023 Jan 12;5(1):3.
- Collinet A, Grimm P, Jacotot E, Julliand V. Biomarkers for monitoring the equine large intestinal inflammatory response to stress-induced dysbiosis and probiotic supplementation. J Anim Sci 2022 Oct 1;100(10).
- Froidurot A, Julliand V. Cellulolytic bacteria in the large intestine of mammals. Gut Microbes 2022 Jan-Dec;14(1):2031694.
- Hain-Saunders NMR, Knight DR, Bruce M, Riley TV. Clostridioides difficile infection and One Health: an equine perspective. Environ Microbiol 2022 Mar;24(3):985-997.
- Rochegüe T, Haenni M, Mondot S, Astruc C, Cazeau G, Ferry T, Madec JY, Lupo A. Impact of Antibiotic Therapies on Resistance Genes Dynamic and Composition of the Animal Gut Microbiota. Animals (Basel) 2021 Nov 16;11(11).
- Di Pietro R, Arroyo LG, Leclere M, Costa MC. Species-Level Gut Microbiota Analysis after Antibiotic-Induced Dysbiosis in Horses. Animals (Basel) 2021 Sep 30;11(10).
- Arnold CE, Pilla R, Chaffin MK, Leatherwood JL, Wickersham TA, Callaway TR, Lawhon SD, Lidbury JA, Steiner JM, Suchodolski JS. The effects of signalment, diet, geographic location, season, and colitis associated with antimicrobial use or Salmonella infection on the fecal microbiome of horses. J Vet Intern Med 2021 Sep;35(5):2437-2448.
- Arnold C, Pilla R, Chaffin K, Lidbury J, Steiner J, Suchodolski J. Alterations in the Fecal Microbiome and Metabolome of Horses with Antimicrobial-Associated Diarrhea Compared to Antibiotic-Treated and Non-Treated Healthy Case Controls. Animals (Basel) 2021 Jun 17;11(6).
- Stöckle SD, Kannapin DA, Kauter AML, Lübke-Becker A, Walther B, Merle R, Gehlen H. A Pilot Randomised Clinical Trial Comparing a Short-Term Perioperative Prophylaxis Regimen to a Long-Term Standard Protocol in Equine Colic Surgery. Antibiotics (Basel) 2021 May 16;10(5).
- Collinet A, Grimm P, Julliand S, Julliand V. Multidimensional Approach for Investigating the Effects of an Antibiotic-Probiotic Combination on the Equine Hindgut Ecosystem and Microbial Fibrolysis. Front Microbiol 2021;12:646294.
- Xing J, Liu G, Zhang X, Bai D, Yu J, Li L, Wang X, Su S, Zhao Y, Bou G, Dugarjaviin M. The Composition and Predictive Function of the Fecal Microbiota Differ Between Young and Adult Donkeys. Front Microbiol 2020;11:596394.
- Arnold CE, Isaiah A, Pilla R, Lidbury J, Coverdale JS, Callaway TR, Lawhon SD, Steiner J, Suchodolski JS. The cecal and fecal microbiomes and metabolomes of horses before and after metronidazole administration. PLoS One 2020;15(5):e0232905.
- Mullen KR, Yasuda K, Divers TJ, Weese JS. Equine faecal microbiota transplant: Current knowledge, proposed guidelines and future directions. Equine Vet Educ 2018 Mar;30(3):151-160.
- Ueda F, Iida A, Saito H, Seki S, Amao A, Yamate H. Assessment of the effect and safety of salacinol in horses. J Equine Sci 2019;30(4):105-111.
- Jin Song S, Woodhams DC, Martino C, Allaband C, Mu A, Javorschi-Miller-Montgomery S, Suchodolski JS, Knight R. Engineering the microbiome for animal health and conservation. Exp Biol Med (Maywood) 2019 Apr;244(6):494-504.
- Harlow BE, Lawrence LM, Harris PA, Aiken GE, Flythe MD. Exogenous lactobacilli mitigate microbial changes associated with grain fermentation (corn, oats, and wheat) by equine fecal microflora ex vivo. PLoS One 2017;12(3):e0174059.
- Almeida ML, Feringer WH Júnior, Carvalho JR, Rodrigues IM, Jordão LR, Fonseca MG, Carneiro de Rezende AS, de Queiroz Neto A, Weese JS, Costa MC, Lemos EG, Ferraz GC. Intense Exercise and Aerobic Conditioning Associated with Chromium or L-Carnitine Supplementation Modified the Fecal Microbiota of Fillies. PLoS One 2016;11(12):e0167108.
- Harlow BE, Lawrence LM, Hayes SH, Crum A, Flythe MD. Effect of Dietary Starch Source and Concentration on Equine Fecal Microbiota. PLoS One 2016;11(4):e0154037.
- Costa MC, Stämpfli HR, Arroyo LG, Allen-Vercoe E, Gomes RG, Weese JS. Changes in the equine fecal microbiota associated with the use of systemic antimicrobial drugs. BMC Vet Res 2015 Feb 3;11:19.
- Du X, Liu M, Li J, Liu Y, Ge S, Gao H, Zhang M. Bifidobacterium animalis Supplementation Improves Intestinal Barrier Function and Alleviates Antibiotic-Associated Diarrhea in Mice. Foods 2025 May 11;14(10).
- Kinoshita Y, Niwa H, Ueno T. Minimal disruption of equine gut microbiota by intravenous cephalothin treatment. J Vet Med Sci 2025 Jun 1;87(6):690-696.
- Hain-Saunders NMR, Knight DR, Harvey A, Bruce M, Hampson BA, Riley TV. Clostridioides difficile in feral horse populations in Australia. Appl Environ Microbiol 2025 May 21;91(5):e0211424.
- Smith MZ, York M, Townsend KS, Martin LM, Gull T, Coghill LM, Ericsson AC, Johnson PJ. Effects of orally administered clioquinol on the fecal microbiome of horses. J Vet Intern Med 2025 Jan-Feb;39(1):e17276.
- 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).
- Froidurot A, Jacotot E, Julliand S, Grimm P, Julliand V. Fibrobacter sp. HC4, a newly isolated strain, demonstrates a high cellulolytic activity as revealed by enzymatic measurements and in vitro assay. Appl Environ Microbiol 2024 Aug 21;90(8):e0051424.
- Mady EA, Osuga H, Toyama H, El-Husseiny HM, Inoue R, Murase H, Yamamoto Y, Nagaoka K. Relationship between the components of mare breast milk and foal gut microbiome: shaping gut microbiome development after birth. Vet Q 2024 Dec;44(1):1-9.
- Boucher L, Leduc L, Leclère M, Costa MC. Current Understanding of Equine Gut Dysbiosis and Microbiota Manipulation Techniques: Comparison with Current Knowledge in Other Species. Animals (Basel) 2024 Feb 28;14(5).
- Gomez D, Toribio R, Caddey B, Costa M, Vijan S, Dembek K. Longitudinal effects of oral administration of antimicrobial drugs on fecal microbiota of horses. J Vet Intern Med 2023 Nov-Dec;37(6):2562-2572.
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
