Sodium Hypochlorite

The water can be a significant risk factor for the occurrence of cattle eimeriosis on farms located in tropical climate regions. This study aimed to assess the viability period of sporulated oocysts of bovine Eimeria spp. in water containing organic matter and to evaluate the efficacy of disinfectants against sporulated oocysts of this protozoa. Two experiments were conducted, each comprising in vitro and in vivo evaluations. In Experiment 1, the viability period of oocysts sporulated in buckets containing a solution composed of a mixture of feces with oocysts, water, and potassium dichromate was assessed. Quantifications and identification of Eimeria spp. oocysts were performed on days + 30, + 60, + 90, and every 30 days thereafter until no more oocysts were detected. Naïve calves were inoculated with this solution kept in the bucket for 6 and 12 months. In Experiment 2, the efficacy of various disinfectants (acetic acid, sodium hypochlorite, ethanol + acetic acid, and ammonia quaternary) against a new solution of sporulated oocysts and pH changes over time (10', 30', and 24 h) were evaluated in the laboratory. The most effective disinfectant was used to treat the water solution and inoculate the calves, and its efficacy was calculated. In Experiment 1, Eimeria spp. oocysts remained viable in the solution for up to 12 months. E. zuernii persisted until the end of the study period. Calves inoculated with the solution kept in the buckets for 6 and 12 months excreted at least four Eimeria species (E. zuernii, E. bovis, E. ellipsoidalis, and E. cylindrica). In Experiment 2, among the tested disinfectants, 3% acetic acid demonstrated the highest efficacy (10' = 80.9%; 30' = 87.9%; 24 h = 91.7%). The pH values of the solutions containing acetic acid ranged from 2.4 to 3.5. Calves that received the inoculum treated with 3% acetic acid did not excrete Eimeria spp. oocysts in feces during the study period (efficacy = 100%). In contrast, all animals in the control group excreted Eimeria spp. oocysts in feces. Future studies should be carried out to better understand the possible effects of cattle drinking water with 3% acetic acid.

Effective methods for decontamination of Shiga toxin-producing Escherichia coli (STEC) on beef were evaluated by 48 mL spraying, 100 mL, and 500 mL flushing with ethanol, hydrogen peroxide, peracetic acid, acidified sodium chlorite, and sodium hypochlorite in this study. The flushing with 500 mL of 1,000 ppm peracetic acid was most effective, reducing pathogens by 2.8 log CFU/cm², followed by 1,200 ppm acidified sodium chlorite. The spraying with 1,000 ppm peracetic acid reduced pathogens by 1.6 log CFU/cm². The flushing with 500 mL of 200 and 500 ppm acidified sodium chlorite, and 50, 100, 200, and 500 ppm peracetic acid significantly reduced the STEC population compared with those treated with distilled water (p < 0.05), reducing pathogens by 2.1, 2.4, 1.6, 1.8, 2.1 and 2.4 log CFU/cm², respectively. Additionally, the flushing with 500 mL of 200 and 500 ppm acidified sodium chlorite significantly changed the color of beef samples (p < 0.05), whereas 100-500 ppm peracetic acid did not significantly change the color (p > 0.05). The flushing with 500 mL of 200 and 500 ppm acidified sodium chlorite and 200 and 500 ppm peracetic acid significantly changed the odor of beef samples compared with those treated with distilled water (p < 0.05). There was no difference in the reduction of STEC population between peracetic acid treatment at 25 °C and 55 °C, with or without washing with sterilized distilled water after decontamination. Washing with distilled water after flushing with peracetic acid tended to reduce the odor of the samples. These results suggest that treatment with 100, 200, and 500 ppm peracetic acid, followed by washing with distilled water, might reduce the STEC population without retaining the odor of the sanitizer.