In vitro chemotactic responses of Brugia pahangi infective larvae to sodium ions

Abstract

In vitro chemotactic responses of infective third-stage larvae (L3) of Brugia pahangi to NaCl, Na 2 HPO 4 , KCl, K 2 HPO 4 , MgCl 2 and CaCl 2 were assessed. Compared to deionized water as a control, 200 mM NaCl and 100 mM Na 2 HPO 4 significantly attracted L3 (P , 0.01 and P , 0.01), whereas L3 were likely to avoid 200 mM KCl and 100 mM K 2 HPO 4 (P , 0.05 and P , 0.05). L3 showed no significant tendency to avoid or to be attracted to 200 mM CaCl 2 and 200 mM MgCl 2 . Furthermore, NaCl exhibited a significant chemoattractant activity for L3 at a low concentration of 100 mM.

Genetic and functional diversification of chemosensory pathway receptors in mosquito-borne filarial nematodes

“…To test conservation of chemosensory function in filarial nematode TRPV channels, we treated infective Brugia L3s with nicotinamide (NAM), an agonist of the C. elegans OSM-9/OCR-4 heteromeric channel (54) , and measured chemotactic responses to host-associated cues. These experiments were performed with Brugia pahangi , a more easily scalable feline-infective filarial parasite that shares in vitro chemotactic behaviors with B. malayi (21,22,24) . B. pahangi L3s freshly extracted from infected Aedes aegypti are strongly attracted to both fetal bovine serum (FBS) and sodium chloride but are weakly repulsed by 3-methyl-1-butanol (a component of human sweat attractive to Strongyloides stercoralis and Anopheles gambiae ) (8,13,49) ( Figure 4A).…”

“…All chemotaxis assays were performed immediately after extraction of L3s from local infections and following previously published protocols (22)(23)(24) . For nicotinamide (NAM, DOT Scientific, Burton, MI) treatment experiments, extracted parasites were first sorted from warm RPMI 1640 into room temperature RPMI 1640, and half of the parasites were placed in media supplemented with a final concentration of 250 µM NAM and incubated for 30 min.…”

“…However, most studies have focused on single-host nematode parasites with direct life cycles, which are phylogenetically distant from the vector-borne filarial parasites of clade III. Recent studies using human-infective Brugia malayi and feline-infective Brugia pahangi , a model species for human LF, reveal the presence of canonical nematode sensory organs (amphids) and robust chemotaxis responses to host-associated cues in vitro (21)(22)(23)(24) . Filarial nematode species also exhibit genus-specific patterns of intra-host migration (25) .…”

Evaluation of the in vitro Activity of Dermaseptin 01, a Cationic Antimicrobial Peptide, against Schistosoma mansoni

“…Male worms of S. mansoni have been found to be more susceptible than female worms in praziquantel resistance studies [5] [32] and studies on the bioactivity of a ginger extract [33]. On the other hand, studies with compounds such as (aminoalkane)thiosulfuric acids [34], 2-(butylamino)-1-phenyl-1-ethanethiosulfuric acid [35], and artenusate [36] showed higher survival rates for males than females. Notwithstanding, our in vitro data demonstrated that DS 01 exhibited activity against adult Schistosoma stages and no significant differences in the mortality rate between male and female worms were observed.…”

“…For example, curcumin, extracted from the rhizome of Curcuma longa [37], some phloroglucinol derivatives obtained from the rhizomes of Dryopteris species [38], and artenusate [36] presented in vitro inhibitory effects on schistosome oviposition. A decrease of the egg output of schistosomes was also observed for Nigella sativa crushed seeds (black seeds) [39] and an extract of ginger rhizomes (Zingiber officinale) [33].…”