title: Detection of assemblages A and B of Giardia duodenalis in water and sewage from São Paulo state, Brazil.
abstract: Giardia duodenalis is a protozoan that parasitizes humans and other mammals and causes giardiasis. Although its isolates have been divided into seven assemblages, named A to G, only A and B have been detected in human faeces. Assemblage A isolates are commonly divided into two genotypes, Al and All. Even though information about the presence of this protozoan in water and sewage is available in Brazil, it is important to verify the distribution of different assemblages that might be present, which can only be done by genotyping techniques. A total of 24 raw and treated sewage, surface and spring water samples were collected, concentrated and purified. DNA was extracted, and a nested PCR was used to amplify an 890 bp fragment of the gdh gene of G. duodenalis, which codes for glutamate dehydrogenase. Positive samples were cloned and sequenced. Ten out of 24 (41.6%) samples were confirmed to be positive for G. duodenalis by sequencing. Phylogenetic analysis grouped most sequences with G. duodenalis genotype All from GenBank. Only two raw sewage samples presented sequences assigned to assemblage B. In one of these samples genotype All was also detected. As these assemblages/genotypes are commonly associated to human giardiasis, the contact with these matrices represents risk for public health.
authors.affiliation: School of Public Health, University of São Paulo, and Hospital da Clínicas, Av. Dr. Arnaldo, 715-Cerqueira César-CEP 01246-904/São Paulo (SP), Brazil. licianatal@usp.br
authors.forename: Licia Natal
authors.initials: LN
authors.lastname: Fernandes
authors.forename: Patrícia Pereira
authors.initials: PP
authors.lastname: de Souza
authors.forename: Ronalda Silva
authors.initials: RS
authors.lastname: de Araújo
authors.forename: Maria Tereza Pepe
authors.initials: MT
authors.lastname: Razzolini
authors.forename: Rodrigo Martins
authors.initials: RM
authors.lastname: Soares
authors.forename: Maria Inês Zanoli
authors.initials: MI
authors.lastname: Sato
authors.forename: Elayse Maria
authors.initials: EM
authors.lastname: Hachich
authors.forename: Silvana Audrá
authors.initials: SA
authors.lastname: Cutolo
authors.forename: Glavur Rogério
authors.initials: GR
authors.lastname: Matté
authors.forename: Maria Helena
authors.initials: MH
authors.lastname: Matté
mesh_terms: D000818:Animals; D001938:Brazil; D016054:DNA, Protozoan / Q000235:genetics; D005838:Genotype; D005872:Giardia / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D005873:Giardiasis / Q000453:epidemiology / Q000469:parasitology*; D005969:Glutamate Dehydrogenase / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012722:Sewage / Q000382:microbiology*; D014871:Water Microbiology
chemical_list: D016054:DNA, Protozoan; D012722:Sewage; D005969:Glutamate Dehydrogenase