A suite of genes expressed during transition to parasitic lifestyle in the trichostrongylid nematode Haemonchus contortus encode potentially secreted proteins conserved in Teladorsagia circumcincta

2010 ◽  
Vol 174 (1-2) ◽  
pp. 106-114 ◽  
Author(s):  
Alexia Delannoy-Normand ◽  
Jacques Cortet ◽  
Jacques Cabaret ◽  
Cédric Neveu
1995 ◽  
Vol 69 (4) ◽  
pp. 357-362 ◽  
Author(s):  
C.E. Rossanigo ◽  
L. Gruner

AbstractIsolates from eight gastrointestinal nematode species parasitic in sheep, cattle and deer were maintained in sheep, to provide eggs in similar faecal environments and to compare temperature and moisture requirements for their development. Faecal cultures were processed at different temperatures (for four species) and moisture contents (for eight species). At 60% of faecal moisture content (FMC), maximal rates of development (expressed as L3/100 hatchable eggs estimated by an extraction technique from the faeves) were observed at 20, 23 and 28°C respectively for Ostertagia leptospicularis, O. ostertagi, Teladorsagia circumcinctaand Trichostrongylus colunriformis. For the eight species, the curves of development rates as functions of FMC were Gaussian, without modification between 18 and 28°C. Optimal developments were when the FMC ranged from 57 to 68%; low development of 1L3/100eggs were observed when the FMC ranged from 85 to 95% and from 25 to 55%. The main differences between species were in the ability of the eggs of Teladorsagia circumcincta, Trichostrongylus colubriformis, T. vitrinusand Chabertia ovina to develop at lower FMC than Haemonchus contortus, O. ostertagi, O. legptospicularis and Cooperia oncophora.


2013 ◽  
Vol 197 (1-2) ◽  
pp. 235-243 ◽  
Author(s):  
J. Moreno-Gonzalo ◽  
F. Manolaraki ◽  
P. Frutos ◽  
G. Hervás ◽  
R. Celaya ◽  
...  

Author(s):  
Nikola Palevich ◽  
Paul Haydon Maclean ◽  
Young-Jun Choi ◽  
Makedonka Mitreva

Abstract Background Haemonchus contortus and Teladorsagia circumcincta are among the two most pathogenic internal parasitic nematodes infecting small ruminants, such as sheep and goats, and are a global animal health issue. Accurate identification and delineation of Haemonchidae species is essential for development of diagnostic and control strategies with high resolution for Trichostrongyloidea infection in ruminants. Here, we describe in detail and compare the complete mitochondrial (mt) genomes of the New Zealand H. contortus and T. circumcincta field strains to improve our understanding of species- and strain-level evolution in these closely related roundworms. Methods In the present study, we performed extensive comparative bioinformatics analyses on the recently sequenced complete mt genomes of the New Zealand H. contortus NZ_Hco_NP and T. circumcincta NZ_Teci_NP field strains. Amino acid sequences inferred from individual genes of each of the two mt genomes were compared, concatenated and subjected to phylogenetic analysis using Bayesian inference (BI), Maximum Likelihood (ML) and Maximum Parsimony (MP).Results The AT-rich mt genomes of H. contortus NZ_Hco_NP and T. circumcincta NZ_Teci_NP are 14,001 bp (A+T content of 77.4 %) and 14,081 bp (A+T content of 77.3 %) in size, respectively. All 36 of the typical nematode mt genes are transcribed in the forward direction in both species and comprise of 12 protein-encoding genes (PCGs), 2 ribosomal RNA (rrn) genes, and 22 transfer RNA (trn) genes. The secondary structures for the 22 trn genes and two rrn genes differ between H. contortus NZ_Hco_NP and T. circumcincta NZ_Teci_NP, however the gene arrangements of both are consistent with other Trichostrongylidea sequenced to date. Conclusions Comparative analyses of the complete mitochondrial nucleotide sequences, PCGs, A+T rich and non-coding repeat regions of H. contortus NZ_Hco_NP and T. circumcincta NZ_Teci_NP further reinforces the high levels of diversity and gene flow observed among Trichostrongylidea, and supports their potential as ideal markers for strain-level identification from different hosts and geographical regions with high resolution for future studies. The complete mt genomes of H. contortus NZ_Hco_NP and T. circumcincta NZ_Teci_NP presented here provide useful novel markers for further studies of the meta-population connectivity and the genetic mechanisms driving evolution in nematode species.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 35-35
Author(s):  
Kelly Froehlich ◽  
Andrew Greer

Abstract Loline, an alkaloid produced by Epichloë endophytes in pastoral grass species, is considered non-toxic with suggested antimicrobial and anthelmintic properties. In vivo metabolism of loline suggests ability to reach the abomasum or intestine, and anthelmintic benefit is indicated in vitro when parasites are in either a developmental stage close to the gastric mucus layers or adult stage consuming blood. Therefore, the objective of this project was to investigate the validation of using a loline seed extract as a natural anthelmintic in parasitized lambs. Sixteen Coopworth lambs were individually penned, offered ad-libitum lucerne pellets and water and randomly assigned to 3 treatment groups; CON; no treatment, or treatment with a Festuca pratensis seed extract with (LOL) or without loline (NIL). Lambs were orally infected with 20,0000 L3 Haemonchus contortus on day 0, and 10,000 L3 Teladorsagia circumcincta, and Trichostrongylus colubriformis on day 14. Parasites then matured to determine lolines efficacy on blood feeding adult Haemonchus contortus and L4 mucosal browsers Teladorsagia circumcincta, and Trichostrongylus colubriformis. Loline was orally dosed at 52.5 mg/kg LW starting on day 13, and every other day until slaughter for worm enumeration on day 28. Feed intake and refusals were recorded daily, and fecal samples were taken prior to infection, on loline dose days and at slaughter. Worm and fecal egg counts were transformed to log10 and all data were analyzed in Genstat (18th edition). Significance was declared at P < 0.05. Worm burdens of T. circumcincta (P = 0.96), T. colubriformis (P = 0.43), and H. contortus (P = 0.15) were not different between treatments. No treatment difference (P = 0.39) was observed in fecal egg counts, weight gain (P = 0.51), or feed intake (P = 0.18). Average growth efficiency (kg LWG/ kg DM intake) was 0.18 in CON which was less (P = 0.01) than LOL (0.24) or NIL (0.23). In conclusion, limited evidence supported an in vivo anti-parasitic effect of loline.


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