Presence of human Giardia in domestic, farm and wild animals, and environmental samples suggests a zoonotic potential for giardiasis.
Giardia lamblia which parasitize humans belong to either of two genotypes, A or B, based on specific signature sequences in the 5' end of the small subunit (16S) ribosomal RNA (rRNA) gene. These two genotypes also were found in cysts from fecal samples of animal origin such as dogs, cats, some farm animals and wild animals. In addition, trophozoites recovered from cysts obtained from environmental samples belonged to these two genotypes as well, suggesting that the G. lamblia genotypes A and B are widespread and possibly zoonotic. Trophozoites were recovered from rats and these isolates might belong to another genotype of G. lamblia. Deer mice and one dog appeared to be parasitized by genotypes of Giardia with close affinity to G. microti. This species, therefore, also consists of a genotype complex.
van Keulen
Harry
H
Department of Biological, Geological and Environmental Sciences, Cleveland State University, 2399 Euclid Avenue, Cleveland, OH 44115, USA. h.vankeulen@popmail.csuohio.edu
Macechko
P Timothy
PT
Wade
Susan
S
Schaaf
Stephanie
S
Wallis
Peter M
PM
Erlandsen
Stanley L
SL
D000818:Animals; D000835:Animals, Wild; D001483:Base Sequence; D002415:Cats; D002417:Cattle; D016054:DNA, Protozoan / Q000737:chemistry / Q000145:classification / Q000235:genetics; D004285:Dogs; D005243:Feces / Q000469:parasitology; D016829:Giardia lamblia / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D005873:Giardiasis / Q000469:parasitology*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D012756:Sheep; D013552:Swine; D014867:Water / Q000469:parasitology; D015047:Zoonoses / Q000469:parasitology*
D016054:DNA, Protozoan; D012336:RNA, Ribosomal, 16S; D014867:Water