In vivo experimental infection of sarcosporidiosis and toxoplasmosis of rabbits in Duhok Province, Kurdistan region, Iraq

Background: Sarcocystis species and Toxoplasma gondii are both zoonotic obligatory intracellular protozoan organisms and cyst-forming coccidian parasites that occur in domestic animals and human throughout the world.Methods: Forty local breed rabbits were divided into four groups, each group ten. Group one were infected with Sarcocystis, group two with Toxoplasma and group three with both parasites and last group was non-infected control group. The LAT serological test was used for detection of anti-toxoplasma antibody in serum of Toxoplasma infected rabbits. The direct impression smears stained with Giemsa was prepared from different body organs including; liver, lung, heart, brain and skeletal muscle for detection of tissue cysts (Bradyzoites) of T. gondii and microcysts of Sarcocystis.Results: In group one, 70% of infected rabbits were positive for toxoplasmosis by serological test; both are and by impression smear method 80% of the rabbits were positive for T. gondii with tissue cysts. Fifty percent of rabbits were positive for microcysts of Sarcocystis by direct impression smear method in group two. In group three, the impression smear and latex agglutination method were positive in 40% and 60% of rabbits, respectively. Statistically, there was no significant difference in detection of toxoplasmosis and sarcocystosis by LAT and impression smear method in group one and three.Conclusions: Rabbits could be source of toxoplasmosis and sarcocystosis and have public health implications and hazard as source of food. They might be source of infection for cats and shed environmentally resistant oocysts.

Virulence of VEG strain Toxoplasma gondii oocysts against Kunming mice / 中国人兽共患病学报

To explore the pathogenicity of VEG strain Toxoplasma gondii oocysts on China Kunming mice,T.gondii oocysts of ＜ 1 and 102-108 were chosen to feed the mice orally.And the modified agglutination test (MAT),H&E and IHC were used to check the infection of mice.The infection rate,the survival rate of mice,and number of cysts in brain were analyzed.Results showed that 100％ of the mice fed with ≥102 oocysts were infected,the minimum lethal dose was 102 oocysts and the 100％ lethal dose was 108 oocysts.The time of death in acute infection was 7 DPI to 14 DPI.T.gondii cysts formation rate was 32.14％ (9/28),and the number of cysts was 9 to 857 per mouse.The survival rate of infected mice was 67.44％ (29/43),and the longest survival time was more than 390 DPI.Accordingly,the virulence of T.gondii VEG strain is medium,and has a higher cysts formation rate.

Virulence and pathogenicity of Toxoplasma gondii ToxoDB# 17 strain oocysts in Kunming mice / 中国人兽共患病学报

To investigate the pathogenic characteristic of ToxoDB # 17 Toxoplasma gondii in Kunming mice,the mice were fed with ＜1,1,101,102,103,104,105,106 oocysts,and the clinical symptoms of mice were observed.MAT,HE and IHC were used to research the infection rate of T.gondii,survival rate of mice and the number of cysts in brain.The results showed that the mice fed with ≥104 oocysts appeared transient depression,mice were arched,messy hair after infection.The mice fed with ≥102 oocysts were all infected,T.gondii cysts formation rate was 2.38％ (1/42),the survival rate of infected mice was 85.71％ (36/42),the survival time was greater than 360 days.In conclusion,the pathogenicity of ToxoDB# 17 T.gondii is weak,and cysts formation rate is also low.

Interaction and cystogenesis of Toxoplasma gondii within skeletal muscle cells in vitro

Infection by the protozoan parasite Toxoplasma gondii is widely prevalent in humans and animals. To prevent human infection, all meat should be well cooked before consumption, since the parasite is present in skeletal muscle. In this context, the use of skeletal muscle cells (SkMCs) as a cellular model opens up new approaches to investigate T. gondii-host cell interactions. Immunofluorescent detection of proteins that are stage-specific for bradyzoites indicated that complete cystogenesis of T. gondii in in vitro cultures of SkMCs occurs after 96 h of infection. Ultrastructural analysis showed that, after 48 h of interaction, there were alterations on the parasitophorous vacuole membrane, including greater thickness and increased electron density at the inner face of the membrane. The present study demonstrates the potential use of primary cultures of SkMCs to evaluate different molecular aspects of T. gondii invasion and cystogenesis and presents a promising in vitro model for the screening of drug activities toward tissue cysts and bradyzoites.

Population biology of Toxoplasma gondii: what's out and where did they come from

Until recently, Toxoplasma gondii was considered to be clonal with little genetic variability. In this paper we summarize recent genotyping data from chickens in Brazil, and pigs, lambs and white-tailed deer in the USA, to demonstrate the high genetic diversity and geographical distribution of T. gondii. A total of 149 T. gondii isolates from 13 geographical areas of Brazil and 182 T. gondii isolates from pigs, 53 isolates from sheep and 15 isolates from fetal white-tailed deer from USA were genotyped using the 10 RCFP-PCR genetic markers SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico. Genotyping of 149 T. gondii isolates from free range chickens in Brazil identified 58 genotype groups. No clonal type II lineage was found. Of the 253 isolates from animals from USA, 18 genotypes were identified, predominantly type II. These studies indicate a higher genetic diversity than previously recognized.