卫氏并殖吸虫感染犬循环抗原和特异性抗体的动态观察

DYNAMICS OF SPECIFIC ANTIBODY AND CIRCULATING ANTIGEN IN SERA FROM THE DOGS INFECTED WITH PARAGONIMUS WESTERMANI

目的观察人工感染卫氏并殖吸虫的犬血清中特异性抗体和循环抗原的动态变化。方法按常规方法从阳性溪蟹中分离卫氏并殖吸虫囊蚴并定量感染家犬,从感染后d4开始采血分离血清,用多抗dot-ELISA法检测犬血中循环抗原(CAg),观察从d4到d133之间感染犬血中循环抗原(CAg)及对感染卫氏并殖吸虫2个月的犬用吡喹酮治疗前后血清循环抗原(CAg)的动态变化。用ELISA法检测从感染2w至19w不同间隔时间内犬血清中特异性抗体(Ab)的动态变化。结果人工感染卫氏并殖吸虫的家犬,有2只犬在感染d6时有循环抗原出现,d10 6只感染犬都能检测到循环抗原,检出稀释度在1∶8～1∶128之间,到感染后14d时,稀释度最高可达到1∶256,并一直维持到34d,56d以后逐渐下降,到84d下降至零。对感染卫氏并殖吸虫的犬用吡喹酮治疗3d后,其循环抗原有短暂出现上升的趋势,但在6d后逐渐下降并消失。感染犬在4周时可检测到特异性抗体,抗体最高滴度维持时间为4周～12周,并一直维持在一个较高的水平上。结论犬在感染卫氏并殖吸虫后的10～56d内,用多抗dot-ELISA法可在其血清中检测到循环抗原(CAg),得出在这段时间检测循环抗原具有早期诊断价值。但感染犬在用吡喹酮药物治疗后有短暂的循环抗原出现,一周后逐渐消失。

Objective In order to observe dynamics of specific antibody and circulating antigen（CAg） in sera of the dogs infected with P.westermani experimentally.Methods Dogs were infected with the metacercaria of P.westermani isolated from freshwater crabs.Sera were collected from the infected dogs from 4 to 133 days for circulating antigen detection,and dynamics of the CAg in the sera of dogs were observed by dot-ELISA before and two months after praziquantel treatment.Dynamics of the specific antibody in sera of the dogs infected with P.westermani were observed with ELISA in different periods from 2 weeks to 19 weeks after the infection.Results Circulating antigen was firstly detected on the 6th day in the infected dog experimentally,and circulating antigen can be detected in all of the 6 dogs on the 10th day,with dilution level from 1∶8 to 1∶128,the highest dilution level being 1∶256 on the 14th day and maintained to 34th day.The dilution title gradually decreased since 56th day to zero on the 84th day.The level of circulating antigen in serum increased temporarily 3 days after treatment with praziquantel for the dogs infected with P.westermani,and gradually decreased since 6th day after treatment until it disappeared.Specific antibody was detected in the infected dogs 4 weeks after the infection,and the highest titer of the antibody was seen from 4 to 12 weeks after infection,and thereafter maintained at a comparatively higher level.Conclusion The circulating antigen can be detected in sera of dogs 10-56 days after the infection,and so it has an earlier diagnostic value.The circulating antigen occurred temporarily after treatment with praziquantel in infected dogs, and disappeared gradually in one week.