气雾剂对肉鸡大肠杆菌感染的保护作用

Protective effect of aerosol spray in broilers infected with Escherichia coli

本研究开展了3个试验探讨气雾噬菌体对感染大肠杆菌肉鸡的保护作用。3个试验均包含9个处理组,每组3个重复,每个重复10只鸡。9个处理组中有3个未感染大肠杆菌组,其中1组不做任何处理,另外2组喷雾PBS或噬菌体气雾剂,其余6个组分别在第7、8和10天感染大肠杆菌,并分别进行PBS喷雾或噬菌体气雾剂。致病性大肠杆菌噬菌体是从城市污水处理设施或家禽加工厂分离出来的。试验1:与对照组相比,第7天感染大肠杆菌接受噬菌体喷雾的肉鸡在第1周体重显著降低(P<0.05),与对照组相比,第7天感染大肠杆菌接受PBS喷雾、第8天感染大肠杆菌接受噬菌体喷雾的3周龄肉鸡体重显著降低(P<0.05)。感染大肠杆菌的肉鸡死亡率均显著高于未感染组(P<0.05)。试验2:感染大肠杆菌的肉鸡在第2周的体重均显著低于未感染组(P<0.05),除了第8天感染大肠杆菌的肉鸡,其他感染组均较未感染组显著降低了第3周体重(P<0.05)。第10天感染大肠杆菌的肉鸡接受噬菌体喷雾较接受PBS喷雾显著降低了死亡率(P<0.05)。试验3:第10天感染大肠杆菌的肉鸡接受噬菌体喷雾较对照组显著提高了第1周龄的体重(P<0.05),接受噬菌体喷雾但未感染大肠杆菌的肉鸡死亡率较对照组以及接受PBS喷雾组显著降低(P<0.05)。本试验结果显示,通过气喷噬菌体对保护肉鸡呼吸道感染大肠杆菌具有重要作用,使用孵化场和家禽舍内的现有设备,在气溶胶喷雾剂中使用噬菌体可适用于家禽养殖业,并可替代抗生素控制家禽细菌性疾病。

Three studies were conducted to determine the efficacy of aerosol administration of bacteriophage to prevent Escherichia coli respiratory infection in broiler chickens.The experimental design consisted of 9 treatments with three replicate pens of 10 birds.Three treatments were not infected with E.coli,which consisted of un-sprayed broilers,broilers sprayed with phosphate buffer saline(PBS,a diluent control),and birds sprayed with a combination of two bacteriophages.Six treatments were infected with E.coli on 7,8,or 10 d of age of broilers,and then sprayed with PBS or bacteriophages.Pathogenic Escherichia coli phages are isolated from municipal sewage treatment facilities or poultry processing plants.Trial 1,compared with the untreated control treatment,the BW at 1 w of the treatment infected with E.coli at 7 d of age and receiving the phage were significantly decreased(P<0.05).The BW at 3 w of the birds,which infected with E.coli at 7 d or 8 d of age and then receiving the PBS spray,were significantly decreased when compared with the untreated control broilers(P<0.05).Mortalities in all the treatment groups infected with E.coli were significantly higher than the treatments that were not infected(P<0.05).Trial 2,the BW at 2 w of broilers infected with E.coli was significantly lower than that of non-infected group(P<0.05).Except for broilers infected with E.coli on the 8th day,the BW of other infected groups was significantly lower than that of non-infected group in the 3 w(P<0.05).Trial 3,broilers infected with E.coli at 10 d of age and then receiving Phage-sprayed were significantly increased the BW at 3 w compared with control group.Mortalities of the birds that received the phage spray without E.coli infection was significantly lower than that of the control group and the PBS spray group(P<0.05).In conclusion,administering bacteriophage as an aerosol spray is effective in preventing E.coli respiratory infections in broiler chicken,and it might be adapted to the poultry industry using existing equipment within the hatcheries and poultry houses and could provide a valuable alternative to the use of antibiotics to control bacterial diseases in poultry.