Parasitology Research

, Volume 117, Issue 11, pp 3675–3678 | Cite as

Carbon dioxide is an absolute requirement for exsheathment of some, but not all, abomasal nematode species

  • Kiliana BekelaarEmail author
  • Tania Waghorn
  • Michael Tavendale
  • Catherine McKenzie
  • Dave Leathwick
Short Communication


The first step in the infection process of grazing ruminants by gastrointestinal nematodes is the exsheathment of the third-stage larva (L3). Exsheathment of various species can be achieved in vitro using carbon dioxide (CO2) under the appropriate temperature and pH conditions. However, it remains unclear whether elevated CO2 levels are an absolute requirement for exsheathment. Exsheathment of four abomasal species was investigated in both the presence and absence of CO2, in either rumen fluid (cow or sheep) or buffer (standard or enriched). Exsheathment of Ostertagia ostertagi, Teladorsagia circumcincta and Ostertagia leptospicularis was observed in CO2-depleted rumen fluid and enriched buffer (respectively 46%, 22% and 15% in rumen fluid and 28% 18% and 26% in enriched buffer after 24 h). The level of this response was dependent on the species as well as the medium, and exsheathment was significantly higher in the presence of CO2. For Haemonchus contortus, exsheathment could only be achieved under CO2-saturated conditions. In conclusion, even though these parasite species exsheath in the same environment, there were significant differences in the minimal requirements to trigger their exsheathment. Some abomasal species were capable of exsheathment in the absence of CO2, which is likely facilitated by cofactors present in the rumen fluid and/or enriched buffer.


Exsheathment Carbon dioxide Parasite Ostertagia Haemonchus contortus 



We thank Peter Janssen, Stefan Muetzel and Alec Mackay for their valuable input on this project.

Funding information

This project was supported by a research grant from the Ministry of Business, Innovation and Employment’s Science and Innovation Group (MBIE), New Zealand (contract C10X1506).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

436_2018_6094_MOESM1_ESM.docx (13 kb)
Supplementary Table 1 (DOCX 12 kb)


  1. Bekelaar K, Waghorn T, Tavendale M, McKenzie C, Leathwick D (2018) Heat shock, but not temperature, is a biological trigger for the exsheathment of third stage larvae of Haemonchus contortus. Parasitol Res 117:2395–2402CrossRefGoogle Scholar
  2. Emery DL, Hunt PW, Le Jambre LF (2016) Haemonchus contortus: the then and now, and where to from here? Int J Parasitol 46:755–769CrossRefGoogle Scholar
  3. Kenters N, Henderson G, Jeyanathan J, Kittelmann S, Janssen PH (2011) Isolation of previously uncultured rumen bacteria by dilution to extinction using a new liquid culture medium. J Microbiol Methods 84:52–60CrossRefGoogle Scholar
  4. Mavrot F, Hertzberg H, Torgerson P (2015) Effect of gastro-intestinal nematode infection on sheep performance: a systematic review and meta-analysis. Parasit Vectors 8:557CrossRefGoogle Scholar
  5. Petronijevic T, Rogers WP (1987) Undissociated bases as the stimulus for the development of early parasitic stages of nematodes. Int J Parasitol 17:911–915CrossRefGoogle Scholar
  6. Petronijevic T, Rogers WP, Sommerville RI (1985) Carbonic acid as the host signal for the development of parasitic stages of nematodes. Int J Parasitol 15:661–667CrossRefGoogle Scholar
  7. Petronijevic T, Rogers WP, Sommerville RI (1986) Organic and inorganic acids as the stimulus for exsheathment of infective juveniles of nematodes. Int J Parasitol 16:163–168CrossRefGoogle Scholar
  8. Rogers WP (1960) The physiology of infective processes of nematode parasites; the stimulus from the animal host. Proc R Soc Lond B Biol Sci 152:367–386CrossRefGoogle Scholar
  9. Rogers WP, Sommerville RI (1960) The physiology of the second ecdysis of parasitic nematodes. Parasitology 50:329–348CrossRefGoogle Scholar
  10. Silverman PH, Podger KR (1964) In vitro exsheathment of some nematode infective larvae. Exp Parasitol 15:314–324CrossRefGoogle Scholar
  11. Sutherland I, Scott I (2010) Gastrointestinal nematodes of sheep and cattle: biology and control. Wiley-Blackwell, ChichesterGoogle Scholar
  12. Taylor A, Whitlock JH (1960) The exsheathing stimulus for infective larvae of Haemonchus contortus. Cornell Vet 50:339–344PubMedGoogle Scholar
  13. VSN International (2016) GenStat for windows 18th Edition vol 18th Edition. VSN International, Hemel HempsteadGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.AgResearch Ltd., Grasslands Research CentrePalmerston NorthNew Zealand

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