Abstract from the German society for Parasitology (DGP) meeting in Duesseldorf

EN

The German society for Parasitology celebrated it’s 50th anniversary this year. Over 150 specialists took part in the annual conference between 16 – 20 March 2010 at the Heinrich Heine university in Duesseldorf.

DE

Die Deutsche Gesellschaft für Parasitologie e.V. veranstaltet im 50. Jahr seit ihrer Gründung ihre 24. Tagung gemeinsam mit der 29. Tagung der Deutsche Gesellschaft für Protozoologie e.V. an der Heinrich-Heine-Universität Düsseldorf. Zwischen dem 16. bis 20. März 2010 sind über 150 parasitologische und protozoologische Fachvorträge und zusätzliche Plenarvorträge geplant. (source dpg website)

For an abstract from the DGP Meeting please click ‘read more’ below.

Reproductive strategies and population biology of Onchocerca filariae in cattle and man

Alfons Renz1, Sarah Reiling1, Adrian Streit2, Daniel Achukwi3

1 Institute of Evolution and Ecology, AG Parasitology, Eberhard-Karls-University, Auf der Morgenstelle 28, D-72076 Tübingen, Germany

2 Max-Planck-Institute for Developmental Biology, Sect. Evolutionary Biology, Spemannstr. 35 – 72076 Tübingen, Germany

3 Institute of Agricultural Research for Development (IRAD), Wakwa Regional centre, Veterinary Research Laboratory, PO Box 65 Ngaoundere, Cameroon

* E-mail corresponding author: Alfons.Renz@uni-tuebingen.de (Alfons Renz)

Abstract

Nodule-forming filariae of the genus Onchocerca are parasites of large mammalians that presumably have evolved in ungulates and only recently spread to other hosts including man.

Cattle in Cameroon harbour at least 4 different Onchocerca species, which often live together in the same individual host, but at highly specific sites: O. ochengi (in the posterior ventral skin, biology very similar to O. volvulus), O. dukei (anterior ventral skin, similar to O. ochengi, but different Simulium vector), O. gutturosa (in the ligamentum nuchae, Ceratopogonidae vectors) and O. armillata (in the aorta wall, vectors yet undetermined).

With a view to the control of human onchocerciasis and the spread of ivermectin resistance, the reproductive behaviour of the worms is of crucial interest: What type and rate of copulations exist in densely or moderately parasitized host, do the male worms prefer to stay with their female partners, once they were lucky enough to find them, until their death? And what about the worms that do not find a partner?

Recent observations from an ongoing study in Northern Cameroon led to an unexpected result: At least in O. ochengi, male worms tend to stay and age together with their female partners and do not, as thought originally, leave the nodule after copulation. These conclusions are based on morphological criteria of freshly isolated worms and are now to be corroborated by molecular genotyping techniques.

For the control of human  onchocerciasis this reproductive behaviour would be good news as it indicates that the filarial parasite invests more into sustainable colonisation of its long-lived host than into genetic variability. The spread of potential resistance in such a model of single partnership would thus be much less quickly if compared to a model with panmixie of the adult worms.

Key words: Onchocerca nematodes, reproductive biology, population biology, mating behaviour, cattle, Cameroon

For more information on the DGP conference in Duesseldorf, please visit http://www.dgp-hhu-2010.de/

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