Genotypic analysis of Giardia duodenalis in domestic cats.
BACKGROUND
Giardia duodenalis is an intestinal flagellated protozoan that affects many mammalian species often causing severe diarrheal disease. Several different genotypes have been identified (Assemblages A-G). Most isolates recovered from domestic cats have been assigned to either Assemblage A, the zoonotic form of the parasite, or Assemblage F, identified thus far only in cats. Genotypic variation within G. duodenalis may influence clinical presentation and course of disease. Therefore, host-adapted genotypes may not be responsible for diarrheal disease (eg, Assemblage F in cats).


OBJECTIVE
Multiple Giardia genotypes will be present in domestic cats, including Assemblage F, which will not be correlated with clinical signs.


METHODS
250 domestic cats from eastern Mississippi and northwestern Alabama.


METHODS
Prevalence survey. Fecal samples evaluated for cysts using a centrifugation concentration technique and a commercially available direct immunoflourescent antibody kit. Giardia isolates were characterized by PCR amplification and sequencing of the glutamate dehydrogenase gene.


RESULTS
Both Assemblage A-I (6/17) and Assemblage F (11/17) were identified. Although Assemblage was significantly associated with age and housing, no association was detected between Assemblage and a variety of other factors including the presence of gastrointestinal signs (acute vomiting, diarrhea, and constipation).


CONCLUSIONS
The presence of diarrhea in domestic cats with Giardia cannot be used as a predictor of the presence of zoonotic genotypes in animals within the study area. Although Assemblage A was associated with age and housing, veterinarians should consider any isolation of Giardia from domestic cats as potentially zoonotic.
Vasilopulos
Robert J
RJ
Department of Clinical Science, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA. azcubfan@comcast.net
Rickard
Lora G
LG
Mackin
Andrew J
AJ
Pharr
G Todd
GT
Huston
Carla L
CL
D000818:Animals; D002371:Cat Diseases / Q000469:parasitology*; D002415:Cats; D005243:Feces / Q000469:parasitology; D014644:Genetic Variation; D005838:Genotype; D005872:Giardia / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D005873:Giardiasis / Q000469:parasitology / Q000662:veterinary*