title: Intra-Species Diversity and Panmictic Structure of Cryptosporidium parvum Populations in Cattle Farms in Northern Spain.
abstract: The intra-herd and intra-host genetic variability of 123 Cryptosporidium parvum isolates was investigated using a multilocus fragment typing approach with eleven variable-number tandem-repeat (VNTR) loci and the GP60 gene. Isolates were collected from intensively farmed diarrheic pre-weaned calves originating from 31 dairy farms in three adjoining regions in northern Spain (País Vasco, Cantabria and Asturias). The multilocus tool demonstrated an acceptable typeability, with 104/123 samples amplifying at all twelve loci. The ML2, TP14, GP60 and the previously un-described minisatellite at locus cgd2_3850 were the most discriminatory markers, while others may be dismissed as monomorphic (MSB) or less informative (CP47, ML1 and the novel minisatellites at loci Cgd1_3670 and Cgd6_3940). The 12-satellite typing tool provided a Hunter-Gaston index (HGDI) of 0.987 (95% CI, 0.982-0.992), and differentiated a total of 70 multilocus subtypes (MLTs). The inclusion of only the four most discriminatory markers dramatically reduced the number of MLTs (n: 44) but hardly reduced the HGDI value. A total of 54 MLTs were distinctive for individual farms, indicating that cryptosporidiosis is an endemic condition on most cattle farms. However, a high rate of mixed infections was detected, suggesting frequent meiotic recombination. Namely, multiple MLTs were seen in most farms where several specimens were analyzed (90.5%), with up to 9 MLTs being found on one farm, and individual specimens with mixed populations being reported on 11/29 farms. Bayesian Structure analysis showed that over 35% of isolates had mixed ancestry and analysis of evolutionary descent using the eBURST algorithm detected a high rate (21.4%) of MLTs appearing as singletons, indicating a high degree of genetic divergence. Linkage analysis found evidence of linkage equilibrium and an overall panmictic structure within the C. parvum population in this discrete geographical area.
authors: Department of Animal Pathology, Faculty of Veterinary Sciences, University of Zaragoza, Zaragoza, Spain.
authors: Ana
authors: A
authors: Ramo
authors: Department of Animal Pathology, Faculty of Veterinary Sciences, University of Zaragoza, Zaragoza, Spain.
authors: Joaquín
authors: J
authors: Quílez
authors: Department of Anatomy, Embriology and Genetics, Faculty of Veterinary Sciences, University of Zaragoza, Zaragoza, Spain.
authors: Luis
authors: L
authors: Monteagudo
authors: Department of Animal Pathology, Faculty of Veterinary Sciences, University of Zaragoza, Zaragoza, Spain.
authors: Emilio
authors: E
authors: Del Cacho
authors: Department of Animal Pathology, Faculty of Veterinary Sciences, University of Zaragoza, Zaragoza, Spain.
authors: Caridad
authors: C
authors: Sánchez-Acedo
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D002417:Cattle / Q000469:parasitology*; D016785:Cryptosporidium parvum / Q000235:genetics* / Q000302:isolation & purification; D008040:Genetic Linkage; D014644:Genetic Variation; D006790:Host-Parasite Interactions; D018598:Minisatellite Repeats; D013030:Spain