Extracting Protostrongylid Nematode Larvae From Ungulate Feces

Abstract

A major weakness of the Baermann funnel technique for extracting nematode larvae from feces is the funnel. As many as 67% of Parelaphostrongylus tenuis first-stage larvae lodged on the sloping surface of glass Baermann funnels. The number of larvae collected after 24 hr was not significantly correlated with total numbers in the samples, whether feces were supported over tissue paper or over window screening. Instead, we collected about 8 times as many larvae and achieved a significant relationship between larvae collected and the total numbers present when pelleted fecal material was submerged over screening in vertical-sided beakers. The methodology of this more efficient and more accurate way of estimating numbers of protostrongylid larvae is described. Most larvae were located on and in the mucous layer covering fecal pellets and readily left fresh pellets emersed in water; 72% of these larvae left after 6 min and only 11% remained after 1 hr. Larvae in water at room temperature sank as fast as 6 cm/min, but those close to a vertical glass surface sank more slowly (97% sank 18.5 cm in 105 min).

A Method for Extracting Genomic DNA from Individual Elaphostrongyline (Nematoda: Protostrongylidae) Larvae and Differentiation of Elaphostrongylus Spp. from Parelaphostrongylus Spp. by PCR Assay

“…infection in cervids is often based on the detection of L 1 s in feces 4,16 ; however, the larvae cannot be identified to the species or genus level because of their morphological and morphometric similarities. 3,4,13 Sometimes the identities of L 1 s are based on the morphological characterization of adults recovered from the host 16 ; however, mixed species infections do occur.…”

“…13 It is believed that E. rangiferi has not spread with caribou from Newfoundland to mainland Canada; however, this needs to be confirmed. 4 The first-stage larvae (L 1 ) of the elaphostrongylines and of several other genera (e.g., Varestrongylus, Muellerius, and Umingmakstrongylus) within the family Protostrongylidae have a characteristic dorsal spine on their tail. 2 The L 1 s of Muellerius and Varestrongylus can generally be distinguished from the elaphostrongyline L 1 s by their shorter length, 9 whereas Umingmakstrongylus occurs only in muskoxen (Ovibos moschatus).…”

“…3,4,13 Sometimes the identities of L 1 s are based on the morphological characterization of adults recovered from the host 16 ; however, mixed species infections do occur. 13,14 Development of diagnostic techniques for the accurate identification of individual elaphostrongyline larvae is important for epidemiological studies and the control of these parasites because they differ in their pathogenicity, host specificity, and geographic distribution.…”

“…Elaphostrongylus cervi L 1 s used in this study were recovered from fecal samples from experimentally infected red deer 7 by using a modified Baermann technique 4 in January 2003. Larvae were placed in tubes containing cryopreservation fluid (50% RPMI media, 39% fetal calf serum, 10% DMSO, and 1% penicillin G and streptomycin sulfate) and were stored in liquid nitrogen.…”

Muscleworms, Parelaphostrongylus Andersoni (Nematoda: Protostrongylidae), Discovered in Columbia White-Tailed Deer From Oregon and Washington: Implications for Biogeography and Host Associations

“…Fecal specimens were extracted for recovery of first-stage protostrongylid larvae using a modified Beaker-Baermann technique (Forrester and Lankester, 1997;Jenkins et al, 2005); numbers of larvae per gram of feces were not quantified. Dorsal-spined larvae of putative elaphostrongyline nematodes were sorted and individual specimens were transferred by micropipette to single cryo-vials with molecular grade water for further processing.…”