Novel non-antibiotic compounds for the control of colibacillosis and Mycoplasma infection in poultry.
PI: Gireesh Rajashekara
Activity 3.3: Novel non-antibiotic compounds for the control of colibacillosis and Mycoplasma infection in poultry.
We will use High Throughput Screening (HTS) to identify novel small-molecule inhibitors against APEC, MG, and MS.
Deletion of the luxS gene decreases the virulence of APEC by 31.5-fold and negatively impacts APEC survival in vivo. Here, using HTS we will identify small molecules that inhibit LuxS as means to control APEC in poultry. This approach will also less likely to have problem of development of resistance by the APEC bacteria.
Factors involved in the virulence and pathogenesis of MS and MG are currently not well defined. Therefore, screening small molecules that inhibit specific virulence characteristics of MS is difficult. Our overall goal is to identity novel bioactive compounds using HTS that have novel mode of action which is not seen in current conventional antibiotics.
Based on the HTS primary screening and other secondary assays, we will select best compounds (up to 5) to evaluate in infected broiler chickens and turkeys against APEC and Mycoplasma, respectively. The small molecules will be administered in water till slaughter age (6-7 weeks) for broilers or 12-18 weeks (commonly the disease symptoms are seen) for turkeys. We expect to identify small molecule inhibitors that will complement existing measures (eg. Poulvac E.coli for APEC) to effectively control APEC and MS in poultry. Once the best candidate is identified, it will be subjected to rigorous screening to evaluate its cytotoxicity in human cells. Since APEC and MS are also a problem in breeder and layer flocks, we will plan to apply our successful approach to these flocks in future investigations. We also plan to apply our approach in a large scale farming operation in the future.
We will identify small molecule inhibitors of LuxS autoinducer production (AI-2) using HTS. For this we plan to screen a library of approximately 5,000 compounds that were identified being highly bioactive from an original screen of approximately 100,000 compounds.
We will identify small molecule inhibitors of MG and MS using HTS. For this we plan to screen a library of approximately 5,000 compounds that were identified being highly bioactive from an original screen of approximately 100,000 compounds.
We will conduct various in vitro studies such as effect of multiple strains, MIC determination, cyctotoxicity studies etc., to prioritize compounds selection for the in vivo studies.
Years 4 & 5:
We will select 5 best compounds from above studies and test for their effect in clearing APEC, MS, or MG infections in broilers and turkeys.