Pseudosuccinea columella: age resistance toCalicophoron daubneyiinfection in two snail populations

Abstract

Individual infections of Egyptian and French Pseudosuccinea columella with five miracidia of Calicophoron daubneyi were carried out to determine whether this lymnaeid was capable of sustaining larval development of this parasite. On day 42 post-exposure (at 23 °C), infected snails were only noted in groups of individuals measuring 1 or 2 mm in height at miracidial exposure. Snail survival in the 2-mm groups was significantly higher than that noted in the 1-mm snails, whatever the geographic origin of snail population. In contrast, prevalence of C. daubneyi infection was significantly greater in the 1-mm groups (15–20% versus 3.4–4.0% in the 2-mm snails). Low values were noted for the mean shell growth of infected snails at their death (3.1–4.0 mm) and the mean number of cercariae (<9 in the 1-mm groups, <19 in the 2-mm snails). No significant differences between snail populations and snails groups were noted for these last two parameters. Most infected snails died after a single cercarial shedding wave. Both populations of P. columella showed an age resistance to C. daubneyi infection and only juveniles measuring 2 mm or less in shell height at exposure can ensure larval development of this digenean up to cercarial shedding.

Transmission of Calicophoron daubneyi and Fasciola hepatica in Galicia (Spain): Temporal follow-up in the intermediate and definitive hosts

“…The observations in relation to C. daubneyi may be the consequence of the development, by the snails, of age-dependent resistance to the miracidial infection and/or the result of the stunted growth induced by the parasite larvae in susceptible snails. By means of experimental infections, Dar et al [43] demonstrated the existence of age-related resistance to C. daubneyi infection in the lymnaeid Pseudosuccinea columella : only the smallest snails of shell height ≤ 2 mm at miracidial exposure were able to sustain complete larval development of the parasite until cercarial shedding. Indeed, Rondelaud et al [19] observed that C. daubneyi caused more severe kidney damage than F. hepatica , in experimentally-infected snails.…”

Pseudosuccinea columella: experimental co-infections of juvenile and pre-adult snails with the digeneans Calicophoron daubneyi and Fasciola hepatica

“…Low values noted for the overall prevalence of C. daubneyi infection in the 3 and 4 mm groups of P. columella may also be interpreted by the same explanation, i.e. the susceptibility of juveniles and the resistance of pre-adults to this parasite (Dar et al , 2015b).…”

“…Two other groups of 100 snails each, measuring 3 and 4 mm in shell height, respectively, were exposed only to five F. hepatica miracidia per snail and served as controls. No control group was constituted with C. daubneyi because all experimental infections of 3 and 4 mm snails carried out with this digenean were negative (Dar et al , 2015b). Snail exposure to miracidia and maintenance were similar to those applied in the first experiment.…”

“…To verify this possibility, experimental infections were carried out using Pseudosuccinea columella . This lymnaeid was age-resistant to C. daubneyi infection and only young snails, measuring 1 or 2 mm at miracidial exposure, could ensure larval development of the parasite up to cercarial shedding (Dar et al , 2015b). In contrast, it is already known to be a natural snail host of F. hepatica (Cruz-Reyes & Malek, 1987; Gutiérrez et al , 2002; Vázquez et al , 2014; Dar et al , 2015a).…”

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“…The results from the experimental infection show that some amphistome species are more infective to a wider range of IH species, while others are specific to certain species. Of these, C. daubneyi (14,18,27,35,38,(55)(56)(57), C. microbothrium (16,(58)(59)(60), Z. lunata (61, 62), and P. cervi (63) infected multiple (≥4) IHs. According to Richards and Shade (64), genetic variations within and between species may account for the variability observed in the degree of infection of each amphistome species to different snail host species.…”