Inactivation effects of slightly acidic electrolyzed water on Cryptosporidium baileyi and Eimeria tenella.

Abstract

Cryptosporidiosis and coccidiosis, caused by Cryptosporidium baileyi (C. baileyi) and Eimeria tenella (E. tenella), are two significant protozoan diseases affecting chicks, leading to substantial economic losses for poultry farmers. Some efforts have focused on the development of antiparasitic compounds that attack both the sexual and asexual stages of the parasites rather than targeting the most infectious stage, the oocyst. Meanwhile, these parasites' oocysts exhibit resistance to many common disinfectants. Slightly acidic electrolyzed water (SAEW) has emerged as a promising sanitizer due to its broad-spectrum efficacy, high efficiency, and no-residue properties. However, limited studies have evaluated the effects of SAEW on C. baileyi and E. tenella. The disinfection efficacy of SAEW against both unsporulated and sporulated E. tenella oocysts was assessed by evaluating oocyst sporulation rates, inhibitory rates of sporulation and invasion, relative weight gain rate (RWG), oocysts per gram of feces (OPG), caeca lesion score (CLS), blood diarrheal score (BDS) and anti-coccidiosis index (ACI). Similarly, the efficacy of SAEW against C. baileyi sporozoites and oocysts was evaluated through sporozoite invasion rates, inhibitory rates of invasion and OPG. SAEW demonstrated partial inhibitory activity against E. tenella oocyst sporulation, with an inhibitory rate of 63.61 % at 12 hours and 14.53 % at 48 hours in the SAEWgroup. The relative weight gain rate of the SAEWgroup was 92.15 %, and the first appearance of bloody stools was delayed by one day. However, SAEW failed to effectively inhibit the invasion of E. tenella sporozoites into DF-1 cells and the production of E. tenella oocysts shedding. When C. baileyi sporozoites were treated with SAEW for 30 minutes, the invasion inhibition rate was 85.52 %. Compared to the positive control group, the reduction rate of C. baileyi oocysts shedding in the SAEWgroup was 77.32 %. The highest peak in the SAEWand SAEWappeared at 15 DPI, two days later than the infection control. SAEW improved (p＜0.05) chick's RWG, CLS, BDS and SR. The highest ACI was significantly observed in SAEWgroup. This study enriches the field of SAEW application and provides valuable reference for the prevention and control of E. tenella and C. baileyi in poultry farms. The findings can help the poultry industry reduce the risk of protozoan infections and subsequent economic losses.