Fayer Ronald, Santín Mónica, Trout James M, DeStefano Stephen, Koenen Kiana, Kaur Taranjit
Environmental Microbial Safety Laboratory, Animal and Natural Resources Institute, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland 20705, USA.
J Zoo Wildl Med. 2006 Dec;37(4):492-7. doi: 10.1638/06-013.1.
Feces from 62 beavers (Castor canadensis) in Massachusetts were examined by fluorescence microscopy (IFA) and polymerase chain reaction (PCR) for Microsporidia species, Cryptosporidium spp., and Giardia spp. between January 2002 and December 2004. PCR-positive specimens were further examined by gene sequencing. Protist parasites were detected in 6.4% of the beavers. All were subadults and kits. Microsporidia species were not detected. Giardia spp. was detected by IFA from four beavers; Cryptosporidium spp. was also detected by IFA from two of these beavers. However, gene sequence data for the ssrRNA gene from these two Cryptosporidium spp.-positive beavers were inconclusive in identifying the species. Nucleotide sequences of the TPI, ssrRNA, and beta-giardin genes for Giardia spp. (deposited in GenBank) indicated that the four beavers were excreting Giardia duodenalis Assemblage B, the zoonotic genotype representing a potential source of waterborne Giardia spp. cysts.
2002年1月至2004年12月期间，采用荧光显微镜检查（IFA）和聚合酶链反应（PCR）对马萨诸塞州62只海狸（加拿大河狸）的粪便进行了微孢子虫属、隐孢子虫属和贾第虫属检测。对PCR阳性标本进一步进行基因测序。在6.4%的海狸中检测到原生生物寄生虫。所有感染的都是亚成体和幼崽。未检测到微孢子虫属。通过IFA从4只海狸中检测到贾第虫属；其中2只海狸通过IFA还检测到隐孢子虫属。然而，这两只隐孢子虫属阳性海狸的小亚基核糖体RNA（ssrRNA）基因序列数据在物种鉴定方面尚无定论。贾第虫属的甘油醛-3-磷酸脱氢酶（TPI）、小亚基核糖体RNA（ssrRNA）和β-贾第素基因的核苷酸序列（已存入GenBank）表明，这4只海狸排出的是十二指肠贾第虫B群，即人畜共患基因型，是水源性贾第虫属包囊的潜在来源。
