Host Association of Cryptosporidium parvum Populations Infecting Domestic Ruminants in Spain

Abstract

A stock of 148 Cryptosporidium parvum DNA extracts from lambs and goat kids selected from a previous study examining the occurrence of Cryptosporidium species and GP60 subtypes in diarrheic lambs and goat kids in northeastern Spain was further characterized by a multilocus fragment typing approach with six mini-and microsatellite loci. Various degrees of polymorphism were seen at all but the MS5 locus, although all markers exhibited two major alleles accounting for more than 75% of isolates. A total of 56 multilocus subtypes (MLTs) from lambs (48 MLTs) and goat kids (11 MLTs) were identified. Individual isolates with mixed MLTs were detected on more than 25% of the farms, but most MLTs (33) were distinctive for individual farms, revealing the endemicity of cryptosporidial infections on sheep and goat farms. Comparison with a previous study in calves in northern Spain using the same six-locus subtyping scheme showed the presence of host-associated alleles, differences in the identity of major alleles, and very little overlap in MLTs between C. parvum isolates from lambs and those from calves (1 MLT) or isolates from lambs and those from goat kids (3 MLTs). The Hunter-Gaston index of the multilocus technique was 0.976 (95% confidence interval [CI], 0.970 to 0.982), which supports its high discriminatory power for strain typing and epidemiological tracking. Population analyses revealed the presence of two host-associated subpopulations showing epidemic clonality among the C. parvum isolates infecting calves and lambs/goat kids, respectively, although evidence of genetic flow between the two subpopulations was also detected.

Multilocus typing and population structure of Cryptosporidium from children in Zaragoza, Spain

“…Both specimens also formed a separate clonal complex by goeBURST analysis and had a unique combination of alleles at MSB and CP47 loci. In fact, it is worthy to note that specimens within each of the three above mentioned subpopulations exhibited distinct alleles at both markers, suggesting that they are also a consistent indicator of membership to a subpopulation, as previously reported for the MSB locus in domestic ruminants (Quílez et al, 2013). No substructure was seen within the C. parvum cluster, which was probably due to the low numbers of samples, since the allelic profile of these specimens was distinct at all but one locus.…”

“…Two isolates were subtyped as IIaA15G2R1, the dominant zoonotic C. parvum in cattle and humans in most industrialized nations (Xiao, 2010). This was the most prevalent GP60 subtype in calves and was also occasionally found in lambs in the same geographical area (Quílez et al, 2011(Quílez et al, , 2013. Interestingly, none of the two latter studies reported the presence of IIaA15G1R1, a rare subtype found in one specimen in this study and previously seen in humans and livestock in Kuwait, Slovenia and Egypt, which could exclude a linking to zoonotic exposure to infected ruminants in our geographical area (Sulaiman et al, 2005;Soba and Logar, 2008;Helmy et al, 2013).…”

Multilocus fragment analysis of Cryptosporidium parvum from pre-weaned calves in Colombia

“…The greatest number of alleles was detected at the ML2 locus (6 alleles), which provided a HGDI value even higher than gp60 sequencing. This microsatellite has been reported to be among the most polymorphic markers for typing C. parvum from humans, pre-weaned livestock or waterborne outbreaks in Europe (Cacciò et al, 2001;Hunter et al, 2007Hunter et al, , 2008Quílez et al, 2011Quílez et al, , 2013Díaz et al, 2012). The most prevalent allele at this marker (ML2-231) was also the most common allelic variant in calves in Spain (Quílez et al, 2011;Díaz et al, 2012;Ramo et al, 2016a).…”

“…Seven markers were either biallelic (ML1, MSB, CP47, MSC6-7) or triallelic (5B12, cgd6_5400, cgd2_3850) but exhibited a major allele accounting for more than 69% of specimens, which explains their low discriminatory index. It is worth mentioning that no variation was found at the TP14 microsatellite, which is considered a relevant locus in multilocus studies in Europe and the United States (Quílez et al, 2011(Quílez et al, , 2013Herges et al, 2012;Hotchkiss et al, 2015). This marker was required to achieve 95% of MLTs in previous studies with either C. parvum or C. hominis (Robinson and Chalmers, 2012).…”

Direct Sequencing of Cryptosporidium in Stool Samples for Public Health

“…Their results also indicated that the resolution of Cryptosporidium population structure was dependent on the genotyping method used (55). Differences in varying extents of host-associated (56,57) and geographical segregation (24,(58)(59)(60), and the extent of panmixia vs. clonality, depending on the population studied (21), have been reported. For example, in Spain, C. parvum in cattle herds was reported to show a panmitic population structure contrasting with sheep where C. parvum populations appeared more clonal (19,61,62).…”