【摘要】 山羊和绵羊口服猪布氏菌二号菌苗都可以产生免疫,其效力与注射免疫大致相等。在多次试验中,在非免疫羊全部感染情况下,服菌苗羊一般有70～80%获得保护,在布氏菌病羊群中进行大群饮服也有效,可制止布氏菌病的流行。猪二号苗给怀孕羊口服不会引起流产,在怀孕羊群中作口服接种是安全的。更多还原

【Abstract】 Oral vaccination of sheep and goats with Brucella suis strain 2 is able to confer a good immu- nity against brucella infection.In two experiments different doses of Strain 9 were given to 4 grou- ps of goats totalling 48 by means of suspending the vaccine in tap water and administering it to anim- als through the mouths with the aid of a long-necked bottle.Five goats were inoculated intra-muscu- larly with the same vaccine for comparison and 33 other goats served as controls.One month later th- ey were mated and in mid-gestation they were challenged with a virulent Strain of Rr melitensis eit- her via conjunctive or by oral route.All animals were killed after abortion or normal parturition and bacterial cultures were prepared in the same way as that described in the preceding reports.Brucella melitnsis infection was demonstrated in 12 of 48 goats given orally 2.5×10~9,25×10~9 or 50×10~9 cel- ls of Strain 2,compared with 1 of 5 inoculated intramuscularly with 2.5×10~9 cells.Of the 33 controls 30 became infected and 20 aborted.The immunity acquired from oral immunization was appro- ximately equivalent to that from intramuscular vaccination. Oral immunization with Br.suis Strain 9 is also able to protect sheep against Br.melitensis infection.Four experiments were carried out on sheep to evaluate the effect of oral immunization ac- cording to the procedures performed on goats.Brucella melitensis infection was demonstrated in 22 of 103 animals receiving 50×10~9,25×10~9 or 10×10~9 cells of Strain 2 from drinking water or feeds, compared with 6 of 26 given 5-12.5×10~9 cells intramuscularly.All of the 57 controls in these expe- riments were seriously infected and 35 aborted.In these experiments 13 other sheep were dosed with 1×10~9 cells before service and received the same dose again in mid-gestation,and 15 other sheep we- re dosed with 15×10~9 cells in mid-gestatlon.None of the 13 animals in the former group and only 2 of 15 animals in the latter group became infected following challenge.It was evident that oral vaccina- tion produced as good an immunity as that induced by intra muscular vaccination and that oral immu- nization of pregnant sheep with Br.suis Strain 9 did not cause abortion.In another experiments there were 17 sheep which were challenged 16(1/2) months after oral immunization.Only 2 of them be- came infected,indicating that the protection produced by oral immunization lasted at least 16(1/2) mon- ths. Oral immunization of sheep and goats had been trialed with success in two communes.In the wi- nter of 1969 an outbreak of brucellosis occurred in two flocks of about 1,200 sheep and goats in Co- mmune A.Blood samples were collected from 428 animals and 114 gave positive reaction to the agglu- tination test.Eight of the reactors were killed and Br.melitensis was isolated from 3.Br.suis st- rain 2 was administered to all animals in the flocks by suspending the vaccine in drinking water.Al- though the majority of the animals in the flocks were pregnant at that time,no abortion due to bruce- lla infection was recorded thereafter. In Commune B there were more than twenty flocks totalling about 23,000 sheep and goats.Bruce- lla infection was prevalent for years.In the lambing season of 1968,205 aborted fetuses were collect- ed for culturing and 44 yielded growth of Br.melitensis.From 1969 to 1972 Br.suis strain 2 was given to all flocks in the commune once a year in the summer by suspending the vaccine in drinking water.In the lambing seasons of 1971 and 1972,81 aborted fetuses were collected for culturing,but none yield brucella.更多还原