鸡白痢沙门菌噬菌体NABTSP16的安全性评价、体内代谢与防控效果OA

Systematically evaluate the biosafety,in vivo metabolic characteristics,and control efficacy of Salmonella pullorum phage,phage NABTSP16 was selected as the research subject.The safety of NABTSP16 in specific pathogen-free(SPF)chicken embryos and chicks,as well as its in vivo distribution patterns in chicks,was evaluated.In addition,a S.pullorum infection model in chicks was established to investigate the protective efficacy of the phage against S.pullorum infection.The results showed that NABTSP16 exhibited no embryotoxicity in SPF chicken embryos,and no abnormalities were observed in the gross morphology or histopathological structure of organs from SPF chicks.In vivo distribution analysis demonstrated that,following intramuscular injection,the phage rapidly distributed to the blood,liver,spleen,and cecal tissues,maintained high activity within 24 h,and exhibited a regular decline after 48 h.In the S.pullorum infection challenge experiment,NABTSP16 achieved a relative protection rate of 71.50%against liver lesions and 63.63%against bacterial clearance.Furthermore,the body weight of chicks in the Phage-treated group was significantly higher than that in the Infected group(P<0.05).These results indicate that phage NABTSP16 has favorable biosafety,broad in vivo distribution,and sustained active phage loads,and exhibits significant protective efficacy against S.pullorum infection.This study provides important experimental evidence for the development of veterinary phage preparations and alternative control strategies for pullorum disease.