TitlePseudocapillaria tomentosa in laboratory zebrafish Danio rerio: patterns of infection and dose response.
Publication TypeJournal Article
Year of Publication2018
AuthorsKent, ML, Gaulke, CA, Watral, V, Sharpton, TJ
JournalDis Aquat Organ
Date Published2018 Nov 06
KeywordsAnimals, Female, Fish Diseases, Laboratory Animal Science, Male, Nematoda, Nematode Infections, Zebrafish

Parasites in wild populations almost always exhibit aggregation (overdispersion), in which relatively few hosts are infected with high numbers of the parasites. This pattern of infection has also been observed in laboratory studies, where many of the sources of natural variation are removed. Pseudocapillaria tomentosa (Nematoda) is common in zebrafish (Danio rerio) facilities. We describe here patterns of infections in zebrafish experimentally infected with larvated P. tomentosa eggs in various trials with defined numbers of eggs. One trial with eggs delivered in a gelatin diet is also included. Fish were exposed at 25, 75, and 200 eggs fish-1, and the minimal infectious dose was estimated to be 1.5 eggs fish-1. The ID50 (50% infective dose) was calculated to be 17.5 eggs fish-1. We also included data from a trial and 2 previously published experiments with undefined doses in which zebrafish were exposed to infectious water and detritus from a tank that previously contained infected fish. All doses resulted in a high prevalence of infection (>70%), except at the 25 eggs fish-1 dose, where the prevalence was 43-46%. Mean abundance of worms corresponded to dose, from 0.57 worms fish-1 at 25 eggs fish-1 to 7 worms fish-1 at 200 eggs fish-1. Variance to mean ratios (V/M) and the k parameters showed aggregation across the 8 separate trials, including the gelatin diet. Aggregation increased with increased parasite abundance. Given the consistent observation of aggregation across our experiments, the zebrafish/P. tomentosa system provides a potentially robust, high-throughput model to investigate factors that influence differences in host susceptibility within defined populations.

Alternate JournalDis Aquat Organ
PubMed ID30460918
PubMed Central IDPMC6474349
Grant ListR21 AI135641 / AI / NIAID NIH HHS / United States
R24 OD010998 / OD / NIH HHS / United States
P30 ES000210 / ES / NIEHS NIH HHS / United States