滑液囊支原体活疫苗(MS-H株)在黄羽肉种鸡中的免疫效果探索

Study on Immune Effect of Mycoplasma Synovia Live Vaccine H Strain in Yellow Breeders

通过评估滑液囊支原体(Mycoplasma synovia,MS)MS-H株活疫苗在黄羽肉种鸡中的免疫效果,为MS在我国鸡群中的感染防控技术研究提供临床参考。该试验通过对6批次黄羽肉种鸡群在21和90日龄分别进行MS活疫苗(H株)免疫,定期测定血清MS抗体水平,并通过三合一方式采集上颚裂拭子检测MS-H株和MS野毒菌株在鸡群中的定殖率或感染率,评估疫苗免疫效果。试验结果表明:①通过血清MS抗体水平检测发现所有鸡群的鸡在1日龄呈现中等水平的MS母源抗体,平均滴度在3000~5000,随着日龄的增加在14、28、42日龄时MS母源抗体基本呈现阴性;而所有鸡群在56日龄时MS抗体陆续转变为阳性。②6批次鸡群中有2批次在42日龄首次检出野毒菌株,阳性率分别为100%、37.5%,其余4批次鸡群分别在70、70、84、112日龄开始检出野毒菌株,阳性率均在25%以下。③通过对MS-H株在鸡群中的持续检测发现6批鸡群在疫苗免疫后1周均检出了MS-H株,大部分鸡群在免疫后3~5周定殖率达到了最高,均超过了80%,部分鸡群的定殖率可达100%,且直到52周龄时MS-H株的检出率仍维持在62.5%~87.5%。可见,MS-H株活疫苗在黄羽肉种鸡中两次免疫,MS-H株可以较好的在鸡群中定殖,持续时间可达52周,且MS抗体水平适中,野毒感染率较低且不能在鸡群中发生大面积的水平传播。因此,MS-H株疫苗在鸡群中两次免疫其疫苗株在鸡群中定殖率较高且维持时间较长,可以阻止MS野毒在鸡群中的感染和水平传播,具有良好的免疫效果。

To evaluate the immune effect of MS-H strain of live vaccine of Mycoplasma synovia(MS)in yellow-feathered breeders,and to provide clinical reference for the research of infection prevention and control technology of MS in chickens of China.Six batches of yellow feather breeder chickens at 21 and 90 days of age were immunized with live MS vaccine(H strain)at one dose,and serum MS antibody levels were measured regularly.The colonization rate or infection rate of MS-H strain and MS wild strain in the chickens were detected by upper cleft palate swab,and the immunization effect of the vaccine was evaluated.The results showed that:1)The detection of serum MS antibody level found that all chickens showed moderate levels of MS maternal antibody at 1 day of age,with an average titer of 3000 to 5000.With the increase of age,the MS maternal antibody was basically negative at 14,28 and 42 days of age.At 56 days of age,the antibody to MS was gradually changed to positive.2)Two of the six batches were detected the MS wild strain at 42 days of age for the first time,and the positive rate was 100%and 37.5%,respectively.The remaining four batches were firstly detected the MS wild strain at 70,70,84 and 112 days of age,respectively,and the positive rate was below 25%.3)The continuous detection of MS-H strains in chicken flocks showed that MS-H strains were detected in all 6 flocks with 1 week after immunization,and the colonization rate of most flocks reached the highest at 3-5 weeks after immunization,exceeding 80%,and some flocks reached 100%.The detection rate of MS-H strain remained at 62.5-87.5%until the 52 weeks of age.Hence,the live MS-H strain vaccine was immunized twice in yellow-feathered breeders,and the MS-H strain could colonize well in the flock,lasting up to 52 weeks,and the antibody level of MS was moderate,the infection rate of wild virus was low,and large-scale horizontal transmission could not occur in the flock.In conclusion,the vaccine MS-H strain has a higher colonization rate and a longer maintenance time after immunization of twice in the chicken population,which has a well immune effect and can prevent the infection and horizontal transmission of MS wild strain in the chicken population.