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

Viral meningitis : an overview

Meningitis is a serious condition that affects the central nervous system. It is an inflammation of the meninges, which is the membrane that surrounds both the brain and the spinal cord. Meningitis can be caused by bacterial, viral, or fungal infections. Many viruses, such as enteroviruses, herpesviruses, and influenza viruses, can cause this neurological disorder. However, enteroviruses have been found to be the underlying cause of most viral meningitis cases worldwide. With few exceptions, the clinical manifestations and symptoms associated with viral meningitis are similar for the different causative agents, which makes it difficult to diagnose the disease at early stages. The pathogenesis of viral meningitis is not clearly defined, and more studies are needed to improve the health care of patients in terms of early diagnosis and management. This review article discusses the most common causative agents, epidemiology, clinical features, diagnosis, and pathogenesis of viral meningitis

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

Tetrahydrobiopterin, l-Arginine and Vitamin C Act Synergistically to Decrease Oxidative Stress, Increase Nitric Oxide and Improve Blood Flow after Induction of Hindlimb Ischemia in the Rat

Nitric oxide (NO) derived from endothelial nitric oxide synthase (eNOS) is a potent vasodilator and signaling molecule that plays an essential role in vascular remodeling of collateral arteries and perfusion recovery in response to hindlimb ischemia. In ischemic conditions, decreased NO bioavailability was observed because of increased oxidative stress, decreased l-arginine and tetrahy-drobiopterin. This study tested the hypothesis that dietary cosupplementation with tetrahydrobiopterin (BH4), l-arginine, and vitamin C acts synergistically to decrease oxidative stress, increase nitric oxide and improve blood flow in response to acute hindlimb ischemia. Rats were fed normal chow, chow supplemented with BH4 or l-arginine (alone or in combination) or chow supplemented with BH4 + l-arginine + vitamin C for 1 wk before induction of unilateral hindlimb ischemia. Cosupplementation with BH4 + l-arginine resulted in greater eNOS expression, Ca2+-dependent NOS activity and NO concentration in gastrocnemius from the is-chemic hindlimb, as well as greater recovery of foot perfusion and more collateral artery enlargement than did rats receiving either agent separately. The addition of vitamin C to the BH4 + l-arginine regimen did further increase these dependent variables, although only the increase in eNOS expression reached statistical significances. In addition, rats given all three supplements demonstrated significantly less Ca2+-independent activity, less nitrotyrosine accumulation, greater glutathione:glutathione disulfide (GSH:GSSG) ratio and less gastrocnemius muscle necrosis, on both macroscopic and microscopic levels. In conclusion, cosupplementation with BH4 + l-arginine + vitamin C significantly increased vascular perfusion after hindlimb ischemia by increasing eNOS activity and reducing oxidative stress and tissue necrosis. Oral cosupplementation of l-arginine, BH4 and vitamin C holds promise as a biological therapy to induce collateral artery enlargement