Loop mediated isothermal amplification (LAMP) of Toxoplasma DNA from dried blood spots.

INTRODUCTION: The cosmopolitan protozoan Toxoplasma gondii is a major parasite of warm-blooded animals including man. Early and accurate diagnosis is a must for proper treatment that prevents life threatening sequels. Loop-mediated isothermal amplification (LAMP) is a novel technique that can amplify DNA with high sensitivity and specificity under isothermal conditions. AIM OF THE STUDY: To validate a LAMP-specific protocol for detection of Toxoplasma DNA using dried blood spots (DBS) from mice experimentally infected with the cystogenic Toxoplasma ME-49 strain. METHODS: In this study, the target DNA fragment was the Toxoplasma 529-bp repeat element that exists in 200-300 copies per T. gondii genome. The sensitivity of both LAMP and conventional PCR techniques was estimated in DBS samples from experimental mice at 1-week and 8-weeks post-infection. RESULTS: Out of 20 blood samples gathered on Whatman filter paper from mice at 1-week post-infection, 18 and 16 were positive by LAMP and conventional PCR, respectively. Neither techniques detected parasite DNA in blood at 8th week of infection. CONCLUSION: Dried blood spots are easy source of material for molecular studies. LAMP assay proved higher sensitivity than the conventional PCR in detecting parasitemia in early infection with the cystogenic Toxoplasma strain.

Comparison of three immunodiagnostic tests for experimental Heterophyes heterophyes infection in dogs.

The aim of this study was to compare the performance of three in-house diagnostic tests, i.e. counter current immunoelectrophoresis (CCIE), intradermal (ID) and indirect fluorescent immunoassay (IFI), for the diagnosis of Heterophyes infection. One hundred and twenty puppies were randomly divided into eight groups (n=15/group). Heterophyes heterophyes infections were established in these puppies by administering a dose of 50 H. heterophyes encysted metacercariae/puppy by gavage. Forty puppies of similar age and sex were divided into eight groups, of five puppies each and were used as negative controls. Sera pooled from separate infected and uninfected groups were tested against H. heterophyes antigens, weekly for 8 weeks post-infection (PI). The ID assay detected infected puppies sooner than any of the serological tests. Sero-conversion was first detected 2 weeks PI by ID assay and 1 week later by CCIE and IFI assays. ID test performed well till the end of the experiment (sensitivity and specificity: 100% and 90%, respectively). Both IFI and CCIE assays had a sensitivity of 40% and 20%, respectively for early detection of antibody, which was less sensitive than ID but both assays were more specific (100%) than the ID assay. The lowest agreement was between ID and IFI tests (40.3%), whilst the highest was observed between CCIE and IFI tests (67.2%). Of the three evaluated methods, the ID test could be recommended for scientific and laboratory diagnosis of heterophyosis in naturally infected animals. However, since none of the investigated method are optimal (i.e, offers 100% specificity and sensitivity), the choice of test employed must depend on the aim of the study.

Enteric parasites can disturb leptin and adiponectin levels in children.

INTRODUCTION: Infection by intestinal parasites in childhood may be the main cause of many health-related problems in developed countries such as anemia, anorexia, loss of appetite, retarded growth and development. The aim of the present study was to assess the effect of different intestinal parasites on white adipose tissue hormones. MATERIAL AND METHODS: Eighty-one children infected by different parasites and 35 apparently healthy children were enrolled in this study. All patients and controls were subjected to clinical examination, measurement of body mass index (BMI) and laboratory examination. RESULTS: For BMI percentiles, there was a significant increase in serum leptin level (p = 0.042) and a significant decrease in serum adiponectin level (p = 0.039) in uninfected children, whereas there were no significant changes in the infected group (p = 0.068 and 0.082 respectively). A significant increase in leptin and decrease in adiponectin levels were observed for E. histolytica, Strongyloides and E. histolytica and Giardia infections compared to the control group (p = 0.047, 0.035 and 0.019 for leptin, and p = 0.025, 0.038 and 0.041 for adiponectin, respectively). CONCLUSIONS: The infection by some intestinal parasites may deregulate the secretion of leptin and adiponectin and also affect the absorption of some nutrients which can disturb the BMI and cause anorexia.

Impact of ApoE genotypes variations on Toxoplasma patients with dementia.

BACKGROUND: Toxoplasma deprives host neuron cells from cholesterol and leads to its ability to potentiate dementia. ApoE intermediates neuronal transmission of cholesterol, which is a key constituent for axonal development, redesigning occasions that are important for education and synaptic arrangement, development of memory and repair of neuron. The aim of this work is to investigate the effect of ApoE genotypes on dementia associated with neurodegeneration in latent Toxoplasma gondii in elderly population. METHODS: This study comprised: 133 patients with dementia (78 were positive for toxoplasma IgG and 55 were negative) and 95 subjects as control group without dementia (30 were positive for toxoplasma IgG and 65 were negative). All of them were subjected to a cognitive assessment, T. gondii seropositivity (ELISA) and determination of ApoE allelic forms (PCR). RESULTS: The ApoE genotype distribution shows that the most predominant genotype is ApoE3/3 and the most widely recognized allele is E3. Both patients and control were further divided into Toxoplasma IgG positive group (n=108) and Toxoplasma IgG negative group (n=120). ApoE4 non carrier, ApoE 2/3 and ApoE 3/3 alleles have highly significant differences (P<0.001) between dementia and non-dementia patients in Toxoplasma infected patients in comparison to non-infected ones. CONCLUSION: Toxoplasma positive patients have more risk to develop dementia regardless ApoE4 carriage.

Helminthes of synanthropic rodents (Rodentia: Muridae) from Dakahlia and Menoufia, Egypt.

A cross-sectional survey was conducted to monitor and compare the prevalence of helminthes in rodents from Dakahlia and Menoufia governorates. The domestic rodents (271) were Rattus norvegicus, Rattus rattus frugivorous, Rattus r. alexandrinus, & Mus musculus. The overall prevalence of helminthes was 52.8%. In Dakahlia, 72/145 rats (49.6%) were infected. The highest prevalence of infection was in R. r. frugivorous 43 (60.4%), then R. r. alexandrinus 44 (47.7%), R. norvegicus 38 (44.7%), and the lowest was M. musculus 20 (40%). In Menoufia, 71/126 rats (56.3%) were infected. The highest prevalence of infection was in R. r. frugivorous 36 (77.7%), then M. musculus 27 (48.1%), R. norvegicus 23 (47.8%), and the lowest was in R. r. alexandrinus 40 (47.5%). A total of 24 species of helminthes (11 trematodes, 4 cestodes & 10 nematodes) were identified among the 271 rodents. The commonest trematode was Mesostephanus aegypticus followed by Stictodora tridactyla. The commonest cestode was Hymenolepis diminuta followed by Taenia taeniaformis. The commonest nematode was Capillaria hepatica followed by Trichurus muris. Given the zoonotic potential of rodents' parasites and since several residential, commercial, and agricultural sites exist in the examined geographic areas, the potential health risk should not be ignored.