实验动物肺孢子菌隐性感染状况调查

目的调查实验动物肺内肺孢子菌隐性感染情况,为其质量监测及选择标准提供依据。方法从本校实验动物部培育的3种6个品系普通级实验动物中随机抽取大鼠、小鼠和兔,取肺脏制成印片标本,分别用姬姆萨(Giemsa)和改良的六亚甲基四胺银(GMS)染色,镜检肺孢子菌的包囊型和滋养体型;用PCR方法检测肺孢子菌特异性DNA。结果①大鼠Giem-sa染色和改良的GMS法阳性率分别为22.6%(12/53)和30.2%(16/53);PCR检测阳性率为49.1%(26/53)。②小鼠Giemsa染色检查全为阴性;GMS染色法检查阳性率为8.5%(8/94)。③用Giemsa和GMS染色检查日本大耳白兔,结果全为阴性。④对比3种动物不同品系的肺孢子菌感染率,GMS染色大鼠、小鼠两者差异显著(P<0.05)。Wistar和SD两种品系大鼠间无显著性差异(P>0.05);昆明株,BALB/c和C57BL/6三个品系小鼠间感染率无显著性差异(P>0.05)。⑤3种检查方法对比:PCR,GMS和Giemsa的阳性率分别为49.1%(26/53),13.6%(24/177)和6.8%(12/177),三者间检出率存在显著性差异(P<0.05)。结论肺孢子菌在普通级实验大鼠及小鼠体内的隐性感染现象较为普遍,其中大鼠的感染率明显高于小鼠。PCR灵敏性高于Giemsa和GMS染色法。

Investigation of the latent Pneumocystis carinii infection in laboratory animal

For defining the quality of experimental animals and offering a reference standard for choice the experimental animals,the latent Pneumocystis infection in laboratory animal was investigated.Total 177 animals come from 6 strains of 3 species was obtained randomly from the experimental animal section,China Medical University.The trophzoite form and cyst form of Pneumocystis was checked by microscopy in the lung smears,which was stained by Giemsa or Gomori's methenamine-silver(GMS).The Pneumocystis specific DNA was detected by PCR.The Pneumocystis trophozoite or cyst form was found in 22.6% by Giemsa and 30.2% by GMS staining;the Pneumocystis specific DNA was detected in 49.1% by PCR in the 53 rats.It was all of negative in the lungs from 94 mouse staining by Giemsa but there were 8.5%(8/94) positive rate by GMS staining.All of 30 rabbits were negative by Giemsa and GMS stains.The latent Pneumocystis infection rate of rat is 30.2%,it was higher comparing with the mice(8.5%) and rabbit(0%) in the GMS stanining samples(P<0.05).The Pneumocystis was detcted in 49.1% by PCR that was significantly higher than Giemsa staning in 6.8% or GMS staining in 13.6%(P<0.05) respectively.It is concluded that latent Pneumocystis infection occurs quite commonly in rat and mice,especially in the rat.The PCR is most sensitivity than Giemsa or GMS staining in decteing the latent infection of Pneumocystis carinii in animals.