Effects of mosquito hemocytes on normal and degenerated oocysts of Plasmodium yoelii and their role in oocyst melanization

ＥｆｆｅｃｔｓｏｆｍｏｓｑｕｉｔｏｈｅｍｏｃｙｔｅｓｏｎｎｏｒｍａｌａｎｄｄｅｇｅｎｅｒａｔｅｄｏｏｃｙｓｔｓｏｆＰｌａｓｍｏｄｉｕｍｙｏｅｌｉｉａｎｄｔｈｅｉｒｒｏｌｅｉｎｏｏｃｙｓｔｍｅｌａｎｉｚａｔｉｏｎ￥ＨｕａｎｇＦｕｓｈｅｎｇ（黄复生）；Ｗ...

A Protocol for a Highly Consistent, High Level Production <i>in Vivo</i>of <i>Plasmodium falciparum</i>Oocysts and Sporozoites

Investigation of the intimate relationship between the human malaria parasite Plasmodium falciparum and its Anopheles vector requires the reliable production and isolation of successive sexual stages of the parasite from infected mosquitoes. Such an advance in propagation would benefit a range of molecular, cellular, immunochemical and transmission-blocking research studies. Parasite cultivation, mosquito rearing, infection and subsequent dissection of mosquitoes are all highly technical procedures that require both skill and experience to perform with competence. Furthermore, to produce mosquitoes of an appropriate age to infect during the short period in which parasites are viable for infection demands precise planning in order to coordinate the interacting life cycles of the parasite and vector. Here, a protocol is described for the complete development of P. falciparum within Anopheles stephensi. A very consistent, high level production in vivo of P. falciparum oocysts and sporozoites is demonstrable by dissection of the mosquito midgut and salivary glands, respectively.

Prevalence of Cryptosporidial Oocysts in Soil of Recreational Parks in Abuja, Nigeria

Contamination of soil with cryptosporidial oocysts poses a great health risk to people especially in individuals who are immune-compromised. Exposure to contaminated soil can cause diarrhoea in humans especially in children who play around the parks and may not wash their hands before handling food. The prevalence of cryptosporidial oocyst in soils of 4 recreational parks in Abuja, Nigeria was investigated. Four hundred soil samples were collected from various locations within the recreational parks and examined for the presence of cryptosporidial oocyst using modified acid fast staining technique. In nine (2.3%) of the samples, 8 were from park A and 1 was from park B contained cryptosporidial oocyst. There was significant association (χ2 = 20.1;df = 2;p = 0.00004) between prevalence of Cryptosporidium oocysts and level of hygiene of the parks. It was concluded that soil in recreational parks may be a source of infection with Cryptosporidium oocysts.

Occurrence of Cryptosporidium oocysts in edible frogs (Rana species) sold for human consumption in Hanwa frog market, Zaria, Kaduna State, Nigeria

Objective: To determine the occurrence of Cryptosporidium oocysts in edible frogs (Rana spp.) sold at the Hanwa frog market, Zaria, Kaduna State, Nigeria. Methods: A total of 117 frogs (Rana spp.) were randomly collected based on consent and availability at the market. The intestinal contents from the frogs were examined by staining flotation and sedimentation smears with modified Ziehl-Neelsen staining technique and microscopy of the oocysts. Results: Overall, 35.9% of frogs sampled from the Hanwa frog market were positive for Cryptosporidium oocysts. There were more Cryptosporidium oocysts detected by sedimentation test (28.2%) than flotation test (23.9%). There was no significant statistical association between sex of frogs and oocyst detection (χ2 = 0.5349, P > 0.05). Also, there was no correlation between the weights of frogs and the sizes of the Cryptosporidium oocysts detected (r = 0.0109, P > 0.05). Nevertheless, female frogs (40%) and frogs within the weight range 170–219 g were more infected with Cryptosporidium (66.7%). Oocysts size range 6.10–7.00 μm had the highest frequency of 10 (23.8%). By size 28.2% of the oocysts detected suggested infection with Cryptosporidium parvum and Cryptosporidium maleagridis. Conclusions: This study has established that edible frogs (Rana spp.) sold at the Hanwa frog market for human consumption were infected with Cryptosporidium spp. which constitutes a valid public health risk especially for immunocompromised individuals.

Growth performance,nutrient digestibility,intestinal morphology,cecal mucosal cytokines and serum antioxidant responses of broiler chickens to dietary enzymatically treated yeast and coccidia challenge

Background There is a growing search for natural feed additives to alleviate the deleterious effects of coccidia infection in poultry production.This study aimed to investigate the effect of enzymatically treated yeast(ETY) on the growth performance,nutrient digestibility,intestinal morphology,antioxidative status,and cecal mucosa cytokines of coccidia-challenged broiler chickens.Methods From d 1 to 14 post hatching,480 broiler chickens were allocated to 3 corn-soybean meal-based experimental diets with increasing concentrations of ETY(0,1,or 2 g/kg).The experiment was designed as a randomized complete block design with body weight(BW) used as a blocking factor.On d 14 post hatching,the birds were re-randomized within each of the 3 experimental diets.Each of the 3 diet groups was split into a challenge or no-challenge group.This resulted in a 3 × 2 factorial arrangement of treatments.The coccidia challenge was administered on d 15 by an oral gavage.Results Dietary ETY improved(P < 0.05) the G:F of birds on d 21 regardless of the challenge state and linearly increased(P < 0.01) the apparent ileal digestibility of dry matter(DM),nitrogen,and gross energy(GE).The coccidia challenge decreased(P < 0.05) BW gain and feed intake of broiler chickens and reduced(P < 0.01) the total tract retention of DM,GE,and nitrogen.The coccidia challenge increased(P < 0.01) the mRNA gene expression of TNFα,IL-1β,IL-10,and IL-6 in the cecal mucosa.There was a tendency(P ne = 0.08) for ETY to linearly reduce IL-1β expression.Additionally,ETY supplementation increased(P < 0.05) the geexpression of OCLN.Serum catalase increased(P < 0.05) with dietary ETY in broiler chickens on d 21.Dietary ETY linearly increased(P < 0.05) the ileal villus height to crypt depth ratio,and ileal goblet cell density in broiler chickens.The ileal and excreta oocyst counts decreased(P < 0.01) with increasing supplementation of dietary ETY in coccidia-challenged broiler chickens on d 21.Conclusions Dietary ETY enhanced nutrient utilization and augmented intestinal development in broiler chickens.However,dietary ETY did not completely attenuate the adverse effects of a coccidia challenge in broiler chickens.

The Effects of Washing Conditions on the Coccidian Oocyst Collection in Chicken Manure

To optimize the production process of occidium vaccine and provide the basis and methods for the production of live vaccine,this experiment uses the collected liquid with different centrifugal forces and centrifugation time,to measure and compare the recovery,purity,collection time and costs of coccidian oocyst,for the purpose of exploring the impact of washing conditions on coccidian oocyst collection in chicken manure.The results show that for the centrifugal machine with the radius of 17.2 cm,the best washing centrifugal rotational speed is 2500 rpm /min,that is,the best washing centrifugal force RCF = 1201.85 g,and the centrifugation time is 12 min.

Assessment of Toxoplasma gondii Contamination in Cat Feces

A study in district Buner,Khyber Pakhtunkhwa,aimed to determine the prevalence of Toxoplasma gondii in cat feces.243 fecal samples were collected and examined for intestinal parasites at Abdul Wali Khan University Mardan.Of these,58 samples(23.86%)were positive for T.gondii oocysts.Samples were collected over five months from November 2016 to March 2017,with varying prevalence rates:20% in November,25.7% in December,22.5% in January,25.9% in February,and 21.9% in March.This was the first study of its kind conducted in district Buner.

Occurrence of Cryptosporidium species in catfish(Clarias gariepinus)Harvested from two lakes and artificial ponds in Zaria,Northern Nigeria

Objective:To determine the occurrence of Cryptosporidium species in catfish(Clarias gariepinus)harvested from two lakes and ponds in Zaria,Kaduna State,Nigeria.Methods:Catfish samples(n=200)from two lakes and(n=200)from two private fish ponds were collected and their gills and gastrointestinal tract samples were analysed for Cryptosporidium oocysts using modified Ziehl-Neelsen staining technique was used,followed by microscopy.Results:Oocysts of Cryptosporidium species were found in all the sampling sites with an overall positivity rate of 49.75%.A comparison between the lakes and ponds as sampling sites revealed a statistically significant(P<0.05)higher percentage of occurrence of Cryptosporidium oocyst from the lakes(39.25%)than from the ponds(10.50%).Conclusions:These findings document for the first time the natural occurrence ofCryptosporidium sp.in catfish intended for human consumption and therefore,underlines the need for public enlightenment to guard against any possible zoonotic transmission.