Seasonal activity of ixodid ticks, parasites of cattle in two bioclimatic areas of Northeastern Algeria

Monthly monitoring of the infestation by ticks of 48 cattle head in six farms was performed in the wilayas (districts) of Mila (semiarid climate) and El Tarf (humid climate) in Algeria, between April 2006 and March 2007. In total, 7024 ticks belonging to four genera and ten species of Ixodidae were collected: Rhipicephalus (Boophilus) annulatus (62.7% of collected ticks) R. turanicus (13.6%), Hyalomma scupense (13.6%), Rhipicephalus bursa (7.7%), H. marginatum (4.7%), H. excavatum (3.9%), H. anatolicum (2.3%), Haemaphysalis punctata (1.5%), Ixodes ricinus (0.7%), and Hyalomma lusitanicum (0.4%). R. annulatus (77.7%) was the most frequent species in El Tarf, whereas H. scupense (39.2%) and R. bursa (17.7%) were dominant in Mila. Many Hyalomma and Rhipicephalus species had a continuous activity throughout the year, with maximum intensity in summer for R. annulatus and H. Scupense, and from spring to fall for R. bursa. The abundance of mesophilic species was low, with winter activity for I. ricinus (exclusively present in El Tarf), and fall activity for Hae. punctata (exclusively present in Mila). The intensity of infestation was significantly higher in adult cattle than in calves under one year old. Tick phenology sometimes differed depending on neighboring countries, showing thus the highly adaptive capability of ticks and the need to carry out regional studies before implementing any control program against ticks or the pathogens they transmit

Failure to observe cross-fertilization between the Echinococcus granulosus G1 and G6 strains after an experimental mixed infection of the definitive host.

The classification within Echinococcus granulosus is currently under debate. To assess the reproductive potential between the G1 and G6 strains, an experimental double infection was carried out in a dog. First, two fertile hydatid cysts were collected in Algeria from a cow and a dromedary. They were identified as being G1 and G6 with the markers coxI and nadI. Subsequently, a dog was inoculated with protoscoleces from these two cysts. Sixty days after infection, 85 adult worms were recovered from the intestine of the dog. Then, the two cysts and each of these individual parasites were characterized with the multilocus microsatellite EmsB and compared. For all worms, the scolex and the gravid proglottids, separately analyzed, provided an identical profile: the G1 profile was observed in 70 adults, and the G6 profile in the 15 others. No single worm exhibited a hybrid G1/G6 profile. This result suggests the absence of cross-fertilizing between the two taxa under the given experimental conditions, and so, the presence of a strong cross-reproductive barrier. This observation corroborates with the recent reclassification of G1 and G6 within two distinct species