Fasciola hepatica infections in cattle and the freshwater snail Galba truncatula from Dakhla Oasis, Egypt.

Infection by Fasciola species was investigated in seven districts of Dakhla Oasis, Egypt, through abattoir inspection of cattle livers for adult worms and sedimentation of faecal samples from local cattle to detect Fasciola eggs. In addition, lymnaeid snails collected from the study area were examined microscopically for developmental stages of Fasciola spp. Abattoir inspection revealed that 51 out of 458 cattle livers (11.1%) contained adult flukes, which were identified morphologically as Fasciola hepatica. Examination of the cattle faecal samples revealed that 142 out of 503 (28.2%) contained Fasciola eggs. The collected snails, identified as Galba truncatula and Radix natalensis, showed larval stages of Fasciola in 71 out of 731 (9.7%) G. truncatula, while R. natalensis showed no infection. Specific duplex polymerase chain reaction (PCR) targeting the mitochondrial cox1 gene of F. hepatica and Fasciola gigantica was carried out on DNA extracted from pooled infected snails and adult worms. The F. hepatica size amplicon (1031 bp) was obtained from both the infected G. truncatula and the adult worms isolated from cattle livers from different districts. The amplicon sequences were identical to the published sequences of F. hepatica mitochondrial cox1 gene. In conclusion, the zoonotic importance of Fasciola infection and appropriate hygienic measures must be taken into consideration in Dakhla Oasis, Egypt.

In vitro study of disinfectants on the embryonation and survival of Toxascaris leonina eggs.

The effect of six available and commercial disinfectants on the embryonation and larval development of Toxascaris leonina eggs was studied. Dettol® and Virkon® both induced a 100% reduction in larval development (P ≤ 0.05). Dettol® resulted in deformed eggshells and a halt in embryonal development at 1 week post exposure. All Virkon®-treated eggs showed an early embryonic lysis 24 h post exposure. TH4+ and 70% ethanol both significantly (P ≤ 0.05) affected larval development, with 58.8 and 85.8% reduction, respectively. Neither sodium hypochlorite nor phenol significantly affected larval development (2.8 and 21.0%, respectively). Sodium hypochlorite treatment caused a visible decortication of the eggshell; however, phenol-treated embryonated Toxascaris eggs appeared more or less morphologically normal. In conclusion, the disinfectants tested induced variable degrees of decortication and suppression of larval development. Virkon®S was the most effective disinfectant against Toxascaris eggs, suggesting that it is the most advisable one to use. To the best of our knowledge, this is the first report of the use of Virkon®S as an ovicide and/or larvicide of helminths, particularly Toxascaris leonina.

Effect of Allium sativum and Allium cepa oils on different stages of Boophilus annulatus.

The study is aimed to investigate the acaricidal effect of Allium sativum (garlic) and Allium cepa (onion) oils on different stages of Boophilus annulatus hard tick. Engorged B. annulatus females were collected from naturally infected cattle. A number of engorged ticks were incubated at 28 °C and 85 % relative humidity to lay eggs, which were incubated to obtain larvae that were used in the study. The used garlic and onion oils were prepared by steam distillation and were analyzed by gas chromatography. These oils were dissolved in ethanol, methanol alcohols, and, partially, in water. The oils were tested in different concentrations; 1, 2, 5, 10, and 20 %. These concentrations were applied on adult ticks by adult immersion test; on larvae by larval immersion technique and on eggs. The 20, 10, and 5 % of garlic oil dilutions in ethanol and methanol killed all adult ticks and larvae within 24 h. Similar results were obtained for 10 and 20 % garlic oil dissolved in water. The effect of 10 % aqueous solution of garlic oil on embryonated eggs was clear as its addition to these eggs led to their in ability to hatch, deformity in shape, and change in color. The 10 and 20 % onion oil in ethanol and methanol alcohols killed 76-86 % of the adult ticks within 72 h post-application. While, all larvae died within 24 h postsubjected to these two concentrations. These concentrations (10 and 20 %) of onion oil in water killed 56-80 % of the treated ticks. Moreover, 10 % aqueous solution of onion oil prevented hatching of embyonated eggs. We concluded that garlic and onion oils have acaricidal effect on all stages of B. annulatus at concentrations higher than 5 %. Only garlic oil could kill 100 % of adult ticks at concentrations from 5 % in alcohols.