Prepatent periods of different Oesophagostomum spp. isolates in experimentally infected pigs

Abstract

To define prepatent periods of different Oesophagostomum spp. isolates we carried out two separate experiments, one using two monospecific laboratory isolates and another using laboratory isolates as well as isolates obtained from pig herds having different management systems and with different anthelmintic treatment histories. Pigs were inoculated with 1,000-2,000 infective larvae. Fecal samples were collected daily beginning on days 15 and 16 postinoculation (p.i.). Fecal cultures were set up at different times to yield larvae that could be identified by DNA analyses. All pigs started to excrete eggs on days 18-24 p.i. The mean prepatent period was 20.2 +/- 1.4 days, with no significant difference being observed between species and isolates. Prepatent periods of 17-19 days were found for the monospecific laboratory isolates of O. dentatum and O. quadrispinulatum. These findings conflict with parasitology textbooks; therefore, suggestions as to the possible reasons for the observed short prepatent periods are given.

Ubiquitin-conjugating enzyme genes in Oesophagostomum dentatum

“…Recent successes with RNAi in parasitic nematodes for selected genes (see Hussein et al 2002;Aboobaker and Blaxter 2004;Lustigman et al 2004;Islam et al 2005;Issa et al 2005) indicate unique prospects for investigating the function of genes directly in O. dentatum. This nematode is considered a unique model for studying the fundamental and developmental biology of parasites (Boag et al 2001(Boag et al , 2003 because it has a rapid and direct life cycle, it produces relatively large numbers of progeny (within a prepatent period of 18-24 days; Talvik et al 1997) and it can also be maintained for longer periods of time in culture in vitro than most bursate nematodes (see Daugschies and Watzel 1999). The results from the present study should provide a basis for discovering the molecular developmental processes associated with UBC-2 in this nematode in vivo and in vitro.…”

“…Talvik et al 1997), which were harvested using the Baermann funnel technique (Ash and Orihel 1987) and stored at 10°C for a minimum of 21 days. Helminth-free pigs (Danish Landrace × Yorkshire × Duroc; both sexes; 20 kg live weight) were inoculated by intragastric intubation with 6×10 3 L 3 .…”

Ecdysis of Oesophagostomum: possible involvement of eicosanoids and development of a bioassay

“…dentatum (strain Hannover) was maintained in pigs and faeces were collected for standard larval culture (Talvik et al 1997). Faecal suspensions containing L3 were set up for small-scale agar migration as described by Talvik et al (1997), and cleaned worms were kept in distilled water at 10°C for a maximum of 2 months. To account for batch-to-batch variation, larvae were used from different batches for the replication of the tests.…”

Oesophagostomum dentatumandTrichuris suisinfections in pigs born and raised on contaminated paddocks

“…Within 23 to 25 days after deposition on pasture O. dentatum eggs may develop into infective freeliving L 3 -larvae (Mejer et al 2000) that are considered to be susceptible to adverse climatic conditions. The pre-patent period may be as short as 17-19 days (Talvik et al 1997). The worms have a low immunogenicity and may accumulate in the host over time.…”