DURATION OF IMMUNITY TO SHEDDING OF TOXOPLASMA-GONDII OOCYSTS BY CATS
DURATION OF IMMUNITY TO SHEDDING OF TOXOPLASMA-GONDII OOCYSTS BY CATS
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DOI：
10.2307/3283823
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发表时间：
1995-06-01
影响因子：
1.3
通讯作者：
DUBEY, JP
中科院分区：
文献类型：
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作者：
DUBEY, JP
有弓形虫卵囊的猫被认为对卵囊的重排具有免疫力。为了研究这种免疫在猫体内是否持续6年，将12只4-6个月龄的猫口服接种弓形虫ME-49株(6只猫)和TS-2株(6只猫)组织包囊。在取食组织囊后4~13天，有2 000万个以上的卵囊脱落。两只猫在初次感染后11至13天发病，1只在第13天死亡，另1只在第11天因全身急性弓形虫病而被杀。在猫排出数百万个卵囊后7天，检查的10只猫的毛发上未发现弓形虫卵囊。在初次感染后第39天，5只猫(2只感染ME-49株，3只感染TS-2株)口服ME-49株的组织包囊。没有一只受到挑战的猫排出卵囊。一只猫死于与弓形虫病无关的原因。在初次感染77个月后，其余9只猫接受了p89株弓形虫组织包囊的口服攻击。这9只猫中有4只重新排出弓形虫卵囊；其中3只在初次感染后39天也受到攻击。两只对照猫与慢性感染猫一起饲养6年后，弓形虫血清仍然呈阴性；这两只猫在攻击p89株后都会排出卵囊。
Cats that have shed Toxoplasma gondii oocysts are considered to be immune to reshedding of oocysts. To investigate if this immunity persists in cats for 6 yr, 12 4-6-mo-old cats without T. gondii antibodies were inoculated orally with tissue cysts of the ME-49 strain (6 cats) and the TS-2 strain (6 cats) of T. gondii. Ah of them shed greater than or equal to 20 million oocysts between 4 and 13 days after feeding tissue cysts. Two cats became ill between 11 and 13 days after primary infection; 1 died on the 13th day, and the other had to be killed on the 11th day because of generalized acute toxoplasmosis. Toxoplasma gondii oocysts were not found on the hair of 10 cats examined 7 days after cats had shed millions of oocysts. On day 39 after primary infection, 5 cats (2 infected with the ME-49 strain and 3 infected with the TS-2 strain) were challenged orally with tissue cysts of the ME-49 strain. None of the challenged cats shed oocysts. One cat died due to causes unrelated to toxoplasmosis. Seventy-seven months after primary infection, the remaining 9 cats were challenged orally with tissue cysts of the P89 strain of T. gondii. Four of these 9 cats re-shed T. gondii oocysts; 3 of them had been challenged also at 39 days after primary infection. Two control cats housed together with chronically infected cats for 6 yr remained seronegative for T. gondii; both of these shed oocysts after challenge with the P89 strain.