title: Diagnosis of gastric cryptosporidiosis in birds using a duplex real-time PCR assay.
abstract: Three species and several genotypes of Cryptosporidium can infect the epithelial surface of the bursa of Fabricius, the respiratory tract, the proventriculus, the intestine, and the urinary tract in birds. There is reason to believe that gastric cryptosporidiosis in birds is caused by Cryptosporidium galli and Cryptosporidium avian genotype III, resulting in a chronic illness of the proventriculus that can lead to a debilitating and fatal clinical condition in birds of the orders Passeriformes and Psittaciformes. The objectives of the present study were to develop a duplex real-time polymerase chain reaction (PCR) that targets the 18S rRNA gene to simultaneously detect C. galli and Cryptosporidium avian genotype III DNA and to compare the duplex real-time PCR results to those of nested PCR targeting a partial fragment of the 18S rRNA gene, followed by sequencing of the amplified products (nPCR/S). A total of 1027 fecal samples were collected from birds of the orders Psittaciformes and Passeriformes originating either from captivity or the wild. Duplex real-time PCR results were positive in 580 (56.47%) and 21 (2.04%) samples, respectively, for C. galli and Cryptosporidium avian genotype III, whereas nPCR/S was positive in 28 (2.73%) and three (0.29%) samples, respectively, for C. galli and Cryptosporidium avian genotype III. Novel host birds were identified for both of the above gastric species, and it was also possible to identify Cryptosporidium baileyi and, for the first time in Brazil, Cryptosporidium avian genotype V. The duplex real-time PCR assay developed in the present study represents a sensitive and specific method for the detection of C. galli and Cryptosporidium avian genotype III in bird fecal samples. Moreover, this method may serve as an alternative to nPCR/S as a gold standard for the diagnosis of gastric cryptosporidiosis in birds.
authors.affiliation: Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, FMVZ, USP, São Paulo, Brazil.
authors.forename: Alex A
authors.initials: AA
authors.lastname: Nakamura
authors.affiliation: Faculdade de Medicina Veterinária, Univ Estadual Paulista, UNESP, Rua Clóvis Pestana, 793 Araçatuba, SP, CEP 16050-680, Brazil.
authors.forename: Camila G
authors.initials: CG
authors.lastname: Homem
authors.affiliation: Divisão Técnica de Medicina Veterinária e Manejo da Fauna Silvestre (DEPAVE-3), Prefeitura do Município de São Paulo, SP, Brazil.
authors.forename: Adriana M J
authors.initials: AM
authors.lastname: da Silva
authors.affiliation: Faculdade de Medicina Veterinária, Univ Estadual Paulista, UNESP, Rua Clóvis Pestana, 793 Araçatuba, SP, CEP 16050-680, Brazil. Electronic address: marcelo@fmva.unesp.br.
authors.forename: Marcelo V
authors.initials: MV
authors.lastname: Meireles
mesh_terms: D000818:Animals; D001483:Base Sequence; D001715:Bird Diseases / Q000175:diagnosis* / Q000469:parasitology; D003001:Cloning, Molecular; D003457:Cryptosporidiosis / Q000175:diagnosis* / Q000469:parasitology; D003458:Cryptosporidium / Q000235:genetics; D016054:DNA, Protozoan; D005243:Feces / Q000469:parasitology; D005767:Gastrointestinal Diseases / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D046109:Passeriformes; D011563:Psittaciformes; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary*
chemical_list: D016054:DNA, Protozoan
keywords: Cryptosporidium avian genotype III; Cryptosporidium galli; Diagnosis; Duplex real-time PCR; Molecular detection