title: Identical assemblage of Giardia duodenalis in humans, animals and vegetables in an urban area in southern Brazil indicates a relationship among them.
abstract: BACKGROUND
  Giardia duodenalis infects humans and other mammals by ingestion of cysts in contaminated water or food, or directly in environments with poor hygiene. Eight assemblages, designated A-H, are described for this species.
  
  
  RESULTS
  We investigated by microscopy or by direct immunofluorescence technique the occurrence of G. duodenalis in 380 humans, 34 animals, 44 samples of water and 11 of vegetables. G. duodenalis cysts present in samples were genotyped through PCR-RFLP of β giardin and glutamate dehydrogenase (gdh) genes and sequencing of gdh. The gdh gene was amplified in 76.5% (26/34) of the human faeces samples with positive microscopy and in 2.9% (1/34) of negative samples. In 70.4% (19/27) of the positive samples were found BIV assemblage. In two samples from dogs with positive microscopy and one negative sample, assemblages BIV, C, and D were found. Cysts of Giardia were not detected in water samples, but three samples used for vegetable irrigation showed total coliforms above the allowed limit, and Escherichia coli was observed in one sample. G. duodenalis BIV was detected in two samples of Lactuca sativa irrigated with this sample of water. BIV was a common genotype, with 100% similarity, between different sources or hosts (humans, animals and vegetables), and the one most often found in humans.
  
  
  CONCLUSIONS
  This is the first study in Brazil that reports the connection among humans, dogs and vegetables in the transmission dynamics of G. duodenalis in the same geographic area finding identical assemblage. BIV assemblage was the most frequently observed among these different links in the epidemiological chain.
authors.affiliation: Environmental and Food Parasitology Laboratory, State University of Maringá (UEM), Paraná, Brazil.
authors.forename: Cristiane Maria
authors.initials: CM
authors.lastname: Colli
authors.affiliation: Environmental and Food Parasitology Laboratory, State University of Maringá (UEM), Paraná, Brazil.
authors.forename: Renata Coltro
authors.initials: RC
authors.lastname: Bezagio
authors.affiliation: Chemical Engineering Department, UEM, Paraná, Brazil.
authors.forename: Letícia
authors.initials: L
authors.lastname: Nishi
authors.affiliation: Engineering and Exact Sciences Centre, State University of West Paraná, Paraná, Brazil.
authors.forename: Thaís Souto
authors.initials: TS
authors.lastname: Bignotto
authors.affiliation: Statistics Department, UEM, Paraná, Brazil.
authors.forename: Érika Cristina
authors.initials: ÉC
authors.lastname: Ferreira
authors.affiliation: Environmental and Food Parasitology Laboratory, State University of Maringá (UEM), Paraná, Brazil.
authors.forename: Ana Lúcia
authors.initials: AL
authors.lastname: Falavigna-Guilherme
authors.affiliation: Environmental and Food Parasitology Laboratory, State University of Maringá (UEM), Paraná, Brazil.
authors.forename: Mônica Lúcia
authors.initials: ML
authors.lastname: Gomes
mesh_terms: D000818:Animals; D001938:Brazil; D003598:Cytoskeletal Proteins / Q000235:genetics*; D004285:Dogs; D005243:Feces / Q000469:parasitology; D005838:Genotype; D016829:Giardia lamblia / Q000145:classification* / Q000235:genetics*; D005969:Glutamate Dehydrogenase / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014675:Vegetables / Q000469:parasitology*; D014867:Water / Q000469:parasitology*
chemical_list: D003598:Cytoskeletal Proteins; D015800:Protozoan Proteins; C038207:giardin protein, Giardia lamblia; D014867:Water; D005969:Glutamate Dehydrogenase