Strategies to Control Coccidiosis and Parasitic Diseases in Biofarms

The use of antibiotics in commercial poultry is being phased out due in part to changing consumer preferences and increased concern for antibiotic resistance. Consumer preference is a major market driver and the use of antibiotics growth promoters over time has led to antimicrobial resistance. This is also true in the case of anticoccidial drugs in Eimeria infections, the causative agent of coccidiosis. Coccidiosis is a widespread and expensive parasitic disease in poultry that results in significant economic losses yearly from performance losses. Because the use of antibiotics is being discouraged, poultry producers are seeking out new methods to mitigate disease from Eimeria in addition to focusing on existing methods such as vaccination. Prevention of coccidiosis is key in minimizing losses and methods that align with organic standards include vaccination, careful flock management, biosecurity, and promoting strong gut health using prebiotics, probiotics, and phytogenic substances. Promoting gut health, which can bolster the overall health of a flock is a high interest and promising avenue for coccidiosis prophylaxis. Phytogenic substances, while shown to aid in gut health, also have merit in reducing coccidiosis severity. Additionally, there are challenges with studying coccidiosis as Eimeria oocysts require a living host to reproduce and amplify. For this reason, in vitro storage is widely used to preserve oocysts for research. To understand how to counter the challenges of coccidiosis in poultry, it is important to examine all phases of Eimeria research, including methods for in vitro research, processing, and storage. The use of avian intestinal enteroids is an interesting method for studying Eimeria host interactions, and autofluorescent microscopy is a promising tool for assessing oocyst integrity in vitro. Current methods for suspending and storing Eimeria oocysts involve aqueous potassium dichromate (PDC), which is a dangerous chemical for lab personnel and has risks associated with its use. Chlorhexidine (CHX) salts, which are gentle enough to be utilized commonly in dental products, demonstrated strong antimicrobial properties and were well tolerated by Eimeria oocysts in suspension. The purpose of this chapter is to address the growing concern of coccidiosis in response to the shift toward organic practices, to discuss potential strategies that can be used to control coccidiosis and to explore new methods for in vitro research and storage of Eimeria oocysts.