title: The CpA135 gene as a marker to identify Cryptosporidium species infecting humans.
abstract: Of the 22 species currently recognized as valid in the Cryptosporidium genus, C. parvum and C. hominis account for most cases of human infections worldwide. However, C. meleagridis, C. canis, C. felis, C. suis, C. muris, as well as the cervine, rabbit and monkey Cryptosporidium genotypes, have also been recognized as the etiologic cause of both sporadic and epidemic cryptosporidiosis in humans. Molecular methods are necessary to distinguish species and genotypes of Cryptosporidium, due to the lack of reliable morphological variations. The aim of this work was to determine the genetic polymorphisms in a fragment of the A135 gene in isolates of C. parvum, C. hominis, C. meleagridis, C. canis, C. muris, C. andersoni and the Cryptosporidium cervine genotype. Primers were designed on conserved regions identified on a multiple alignment of the C. parvum, C. hominis and C. muris sequences, the three species for which information is available at the genome level. PCR amplification and direct sequencing of a 576 bp fragment revealed the presence of numerous single nucleotide polymorphisms (SNPs) among the species/genotype tested. The genetic variability was exploited to design a PCR-RFLP assay useful for a rapid identification of the most important human pathogens in the genus Cryptosporidium.
authors.affiliation: Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy. fabio.tosini@iss.it
authors.forename: Fabio
authors.initials: F
authors.lastname: Tosini
authors.forename: Rosanna
authors.initials: R
authors.lastname: Drumo
authors.forename: Kristin
authors.initials: K
authors.lastname: Elwin
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Chalmers
authors.forename: Edoardo
authors.initials: E
authors.lastname: Pozio
authors.forename: Simone M
authors.initials: SM
authors.lastname: Cacciò
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D003457:Cryptosporidiosis / Q000175:diagnosis* / Q000469:parasitology; D003458:Cryptosporidium / Q000145:classification* / Q000235:genetics; D005838:Genotype; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods*; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics*; D012680:Sensitivity and Specificity; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: C514023:Cpa135 protein, Cryptosporidium parvum; D008562:Membrane Glycoproteins; D015800:Protozoan Proteins