Associate ProfessorGary Muscatello

Project Opportunities

Title: Virulent Rhodococcus equi decontamination strategies on horse farms

Summary of opportunity:

An investigation into potential disinfectant agents that could be used on farms to reduce environmental virulent Rhodococcus equi burdens.

Opportunity synopsis:

The aim of this project is to investigate disinfectant agents (such as, lime, chlorine and the common phenols and quaternary ammonia compounds) that could be used in the field to effectively kill virulent Rhodococcus equi. The experiments will commence by examining the effects of the various agents on the growth of virulent R. equi under standard culture condition, then evaluating their impact on the growth of virulent R. equi in inoculated soil samples from Thoroughbred breeding farms in the Hunter Valley. Bacterial growth will be evaluated using standard spectrophotometer methods complemented by direct dilution plating and PCR analysis to evaluate virulence of the organism. Once the laboratory findings have been evaluated, evaluation of the agent(s) in the field will be contacted. In this process the agent(s) impact will be evaluated through seasonal monitoring of the bacterial levels and the prevalence of R. equi pneumonia on participating farms. Safety issues will also be assesses in a small scale study on horse environments at the Camden campus.At the conclusion of this project, findings will indicate whether disinfectant agents could be used to reduce the concentration of virulent R. equi on Thoroughbred breeding farms and it may result in the production of national and internationally recognized management practices to reduce the significance of R. equi pneumonia in the equine breeding world.

Project Opportunities

Title: An investigation into symbiosis between virulent Rhodococcus equi and protozoa

Summary of opportunity:

Can virulent Rhodococcus equi replicate within protozoa found in the soil and gastrointestinal environment of the foal?

Opportunity synopsis:

The aim of this project is to ask (and hopefully answer) the question, can virulent R. equi replicate within foal gastrointestinal and soil protozoa? Given that the organism is a facultative intracellular parasite the likelihood of a symbiotic relationship existing between it and equine and soil associated protozoa is high. Such a relationship may provide a survival niche to facilitate amplification without the need for invasion into the alveolar macrophage, significantly increasing environmental levels and the likelihood for a substantial pulmonary insult from contaminated dust. The project will involve the examination of fresh faecal samples from foals, post-mortem foal gastrointestinal samples and protozoal resuscitated soil samples from R. equi endemic farms. Utilizing monoclonal antibodies (mAbs) to VapA, a cell-surface virulence protein, immunohistochemistry will be used to hopefully reveal the true location of virulent R. equi in these samples. Complementary qPCR and PCR techniques using universal protozoal PCR and qPCR methods combined with established virulent R. equi PCR and qPCR methods will be used to reveal the extend if any of amplification of virulent R. equi associated with protozoal numbers. In vitro soil or pure protozoal culture experiments will be performed in concert with field and archival soil sample examinations. The findings of this study will be of great significant in the equine veterinary community and the general infectious disease community. Findings may lead to prophylactic strategies focusing on modifying the protozoal environment in the developing foal and the use and development of specific antiprotozoal oral therapy targeting the protozoal amplifier.