Year-end Sale % OFF 
Abstract
Ovine Eimeria spp. infections cause increased mortality, reduced welfare and substantial economic losses, and anticocccidials are important for their control. Recent reports of anticoccidial resistance against ovine Eimeria spp. necessitate the development of in vitro methods for the detection of reduced anticoccidial efficacy, especially since the in vivo methods are both expensive, time consuming and requires the use of otherwise healthy animals. The aim of the present study was therefore to approach a preliminary standardization of in vitro assays for evaluation of the efficacy of the most commonly used anticoccidials in ruminants. For this purpose, apart from the evaluation of inhibition of oocyst sporulation, most effort was concentrated on assessment of the capacity of the different anticoccidials to inhibit both the invasion and further development (up to the first schizogony) of E. ninakohlyakimovae sporozoites in bovine colonic epithelial cells (BCEC). For this purpose, infected cultures were monitored 1, 8 and 15 days post infection to determine the infection rate, number of immature schizonts and number, size and appearance of mature schizonts, respectively. No clear inhibitory effect was found with any of the anticoccidial formulations tested, and we could not identify why there were no measurable effects from the different anticoccidials. Despite the lack of positive results, further investigations should be encouraged, as this could decrease the need for animal experiments and could be used in the initial assessment of anticoccidial efficacy of new drugs.
Highlights
Infections caused by Eimeria species are some of the most important parasitic diseases affecting the profitability of ruminant production systems (Keeton and Navarre, 2018)
The highest invasion rate for the commercial anticoccidials was seen for 0.1 μg/ml decoquinate at 39.7%, and for the pure source/metabolite anticoccidials for 5 μg/ml TN at 39.3%
In the present study we assessed the ability of E. ninakholyakimovae sporozoites to invade and further develop up to first schizogony in bovine colonic epithelial cells (BCEC) in the presence of different concentrations of anticoccidials or controls
Summary
Infections caused by Eimeria species are some of the most important parasitic diseases affecting the profitability of ruminant production systems (Keeton and Navarre, 2018). The control of ruminant coccidiosis is traditionally based on the combination of good management together with prophylactic or metaphylactic treatment with anticoccidials (Daugschies and Najdrowski, 2015). Toltrazuril resistance has been confirmed in porcine Cystoisospora suis (Sheresta et al, 2017), and in ovine Eimeria spp. Toltrazuril resistance in ovine Eimeria spp. in Norway is probably related to the widespread and extensive use of anticoccidial (AC) treatment in this country, as discussed in a recent publication based on a questionnaire study and aiming to identify potential risk behaviour for development of ACR (Odden et al, 2017)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
