Effects of iron chelating agent on Schistosoma mansoni infected murine model.

Schistosomiasis is one of the major health problems in many tropical and developing countries. Infection takes place once cerceriae penetrate human skin, then it changed into schistosomules. The schistosomules takes iron in the form of heme from host's haemoglobin, ferritin and transferrin. Iron is a vital element not only for growth and sexual maturity of schistosomules to adults but also for oogenesis. Since the trapped eggs are the pathological causative agent for most of pathogenesis and complications, the current work was designed to study the effects of early deprivation of schistosomules from iron in the host (in vivo) by chelating it with deferoxamine (DFO). The iron chelation has effects on growth, maturity and egg deposition, as well as it has ameliorative effects on liver pathology such as hepatic fibrosis. Mice were classified into four groups, normal control, DFO treated only, Schistosoma mansoni (S. mansoni) infected DFO untreated and S. mansoni infected DFO treated. The infected DFO treated mice showed significant reduction in fecal egg excretion with increased percentage of dead eggs and this was accompanied with a significant reduction of both total worm burden and hepatic egg load and increased dead egg percentage compared to the infected DFO untreated group. There was also a significant reduction in both serum and hepatic tissue ferritin concentrations in the infected DFO treated mice in comparison to the infected DFO untreated group. Additionally, a significant decrease in number and size of granulomas with subsequent improvement of liver fibrosis was recorded in the infected DFO treated group. This immunopathology was also associated with significant up regulation of Interlukine12 (IL12), Interferon gamma (IFN γ) and significant down regulation in interleukin4 (IL4), interleukin10 (IL10) in both serum and hepatic tissue in the infected DFO treated compared to other groups. Entirely, DFO succeeded in diminishing the growth, maturity and fecundity of S. mansoni with a subsequent improvement of hepatic pathology. As a result of the above findings, it can be concluded that DFO could be considered as a useful treatment against schistosomal infection.

Quantitative assessment of the effects of sulfamethoxazole on Toxoplasma gondii loads in susceptible WT C57BL/6 mice as an immunocompetent host model.

The abundance of Toxoplasma gondii with or without sulfamethoxazole (SMX) treatment was evaluated with quantitative competitive polymerase chain reaction in various organs of wild-type C57BL/6 mice, a susceptible immunocompetent host, after peroral infection with a cyst-forming Fukaya strain of T. gondii. SMX affected different organs in three ways: T. gondii was reduced independently of SMX (skin and kidney); T. gondii was not eradicated with continuous treatment (brain, heart, and lung); and T. gondii was eradicated with continuous treatment (tongue, skeletal muscle, and small intestine). The SMX concentrations in the brains, hearts, and lungs were higher in infected mice than in uninfected mice. These results indicate that even in an immunocompetent host, chemotherapy is necessary to reduce the parasite load and thus reduce the risk of recurrent disease.

Human wound myiasis caused by Phormia regina and Sarcophaga haemorrhoidalis in Minia Governorate, Egypt.

Myiasis is the parasitic infestation of human by the larvae (maggots) of dipterous fly that grow within the host while feeding on its tissue. Cutaneous myiasis is the most considerably encountered clinical form. Moreover, wound (traumatic) myiasis is the main clinical manifestation of cutaneous myiasis. In this research, we aimed to study the type of infesting larvae that are responsible for wound myiasis in the patients in Minia city, Egypt. Three cases of wound myiasis have been noticed among 280 patients with wounds at different parts of bodies. Two of them were diabetic patients. The third one had a history of hypertension with right side hemiplegia 2 years ago. All of them were elderly. The larvae removed from cases 1 and 3 were identified macroscopically and microscopically as the third-stage larvae of Sarcophaga haemorrhoidalis. The larvae removed from case 2 were the third-stage larvae of Phormia regina, which is very rare worldwide. In addition to the open and obsolete wound, diabetes mellitus and low socio-economic circumstances were shown to be attributed as important predisposing risk factors that led to the occurrence of myiasis in these patients.

In vitro effect of some Egyptian herbal extracts against Blastocystis hominis.

Blastocystis hominis is an enteric parasite that inhabits the gastrointestinal tract of humans and many animals. This emerging parasite has a worldwide distribution. It is often identified as the most common eukaryotic organism reported in human fecal samples that showed a dramatic increase in recent years. Metronidazole is the main therapy for blastocystosis. However, frequent reports of treatment failure suggesting isolates resistance to metronidazole. This study determined the growth pattern and in vitro susceptibility of B. hominis to nitazoxanide (NTZ), garlic, ginger, onion and turmeric. Fecal samples positive for Blastocystis were collected from patients with irritable bowel syndrome (IBS), and processed for culture. Cultured samples were subjected to examination by light microscopy. Herbs' extracts was freshly prepared. Drug susceptibility assays was done using 0.1 mg/ml of NTZ, garlic, ginger, onion and turmeric. Effects assessed on parasite culture after 24 hr. and 48 hr. Cultured fecal samples of B. hominis have identified several forms of the organism; vacuolar, granular, amoeboid and cyst forms within 24 hr. Nitazoxanide treatment significantly (P < 0.001) lowered the parasite number after 48 hr. (mean, 337.5 ± 17.67) /ml. The reduction rate after 48 hr. compared to PBS was 93.33%. Ginger treatment significantly (P < 0.002) lowered the number of the parasite after 48 hr. (mean, 335 ± 7.07)/ml. Moreover, garlic treatment also significantly (P < 0.002) lowered the number of the parasite after 48 hr. (mean, 382.5 ± 10.60)/ml. The reduction rates after 48 hr. in these treated samples compared to PBS were 92.98% and 92.44% respectively. However, onion, and turmeric treatments insignificantly lowered the number of the parasite after 48 hr. (P < 0.15 & < 0.22 respectively).

Polymerase Chain Reaction: A Better Method for Diagnosing Chronic Schistosoma mansoni Infections.

For more effective diagnosis of the acute and chronic stages of Schistosoma mansoni infection in humans, the polymerase chain reaction (PCR) technique was compared with the Kato-Katz method. A total of 150 stool samples were collected from inpatient and outpatient clinics at the Department of Tropical Medicine, Minia University Hospital, Egypt. Three groups of patients, 50 with acute intestinal schistosomiasis, 70 with chronic intestinal schistosomiasis and 30 normal healthy controls were studied. Stool samples were analyzed by PCR and the Kato-Katz method. The mean number of eggs per gram of feces was 4.6 when estimated by the Kato-Katz method in positive stool samples from acute schistosomiasis cases but only 1.7 in chronic cases. In acute intestinal schistosomiasis, 15 and 45 out of 50 cases were positive by Kato-Katz and PCR, respectively. In the chronic intestinal schistosomiasis cases, 6 and 68 out of 70 cases were positive by the Kato-Katz and PCR methods, respectively. We conclude that PCR appears to be an effective diagnostic technique for S. mansoni infection, especially where a low worm burden exists, such as in chronic cases.

Human Cystic Echinococcosis in the Nalut District of Western Libya: A Clinico-epidemiological Study.

Human cystic echinococcosis (CE) is an endemic disease in the Mediterranean area that has not yet been fully documented in western Libya. The present study describes the clinico-epidemiologic profile of CE in western Libya's Nalut district. From April 2008 to July 2011, 36 cases of CE were confirmed following surgical removal of cysts. The cysts were most frequently found in the liver (61.1%), followed by the lungs (19.4%), kidneys (11.1%), peritoneal cavity (11.1%), and spleen (5.6%). Among the 36 patients, 6 possessed plural cysts and 3 had cysts in 2 organs. Blood samples from this group were examined for the presence of serum anti-hydatid IgG antibodies, which revealed positivity in 25 patients (69.4%). An additional 300 blood samples were collected randomly from the inpatient and outpatient clinics at Nalut Hospital. Twenty-seven samples (9%) were found to be positive for the anti-hydatid IgG antibody among which the prevalence of infection tended to be higher in men (12%) than in women (6%). This study demonstrates that CE is a major parasitic infectious disease of public health significance in Libya, notably in the western part of the country, and that disease awareness needs to be raised nationwide.

Innate immunity in DNA vaccine with Toxoplasma gondii-heat shock protein 70 gene that induces DC activation and Th1 polarization.

Toxoplasma gondii-derived heat shock protein 70 (T.g.HSP70) is a tachyzoite-specific virulent molecule expressed before the death of hosts. We have already demonstrated the vaccine effects of T.g.HSP70 gene targeting peripheral epidermal or dermal dendritic cells (DC) to limit T. gondii loads in T. gondii-infected mice. In the present study, involvement of innate immunity in T.g.HSP70 gene vaccine-induced Th polarization at draining lymph nodes (dLN) of C57BL/6 (B6) mice and vaccine effects against toxoplasmosis have been evaluated. Compared to the mice unvaccinated or vaccinated with empty plasmid, CD11c(+) cells at the dLN from naïve B6 mice expressed prominent IL-12 mRNA after the T.g.HSP70 gene vaccine. Also, CD4(+) cells at the dLN from the mice expressed prominent interferon-γ, but not IL-4 or IL-17, mRNA at a maximum level at day 5 following vaccination. Thus, in vivo DC activation and successive early Th1 polarization were induced at the dLN of naïve mice by the T.g.HSP70 gene vaccine. The DC activation and Th1 polarization were observed at the dLN from wild type (WT) and Toll-like receptor (TLR) 2-deficient mice, but not TLR4-deficient mice with B6 background by the vaccine. This T.g.HSP70 gene vaccine-induced DC activation and Th1 polarization were also observed in TRIF-deficient mice, but not MyD88-deficient mice with B6 background indicating the involvement of TLR4/MyD88 signal transduction cascade in the vaccine effects with T.g.HSP70 gene. The T.g.HSP70 gene vaccine (twice at a 2-week interval) has been shown to limit T. gondii loads in the mesenteric LN of WT, TLR2-deficient and TRIF-deficient mice, but neither TLR4-deficient nor MyD88-deficient mice, at an acute phase of toxoplasmosis. The T.g.HSP70 gene vaccine also limited cyst number in the brains of WT, TLR2-deficient and TRIF-deficient mice, but not TLR4-deficient mice at a chronic phase of toxoplasmosis. Thus, innate immunity also has effects on the vaccine with T.g.HSP70 gene against acute and chronic phases of toxoplasmosis.

Evaluation of the effects of sulfamethoxazole on Toxoplasma gondii loads and stage conversion in IFN-gamma knockout mice using QC-PCR.

Toxoplasma gondii abundance with or without sulfamethoxazole treatment was evaluated by quantitative competitive polymerase chain reaction (QC-PCR) assay in various organs of IFN-gamma knockout BALB/c (B/c) mice after peroral infection with the cyst-forming Fukaya strain. T. gondii infection was observed in the brain, skin, tongue, heart, and skeletal muscle of the mice treated with sulfamethoxazole, although the parasite was not observed during the treatment in the mesenteric lymph node, spleen, small intestine or kidney. After discontinuing the therapy, T. gondii reappeared within five days in all organs. Reverse transcriptase (RT)-PCR showed that sulfamethoxazole treatment accelerated the stage conversion of T. gondii from tachyzoites into bradyzoites in the brain, lung, and heart. In contrast, after discontinuing sulfamethoxazole treatment, T. gondii underwent stage conversion from bradyzoites into tachyzoites in these organs. These results indicate that we successfully established an animal model for evaluating chemotherapy regimens in immunocompromised hosts infected with T. gondii.

Induction of protective immunity by primed B-1 cells in Toxoplasma gondii -infected B cell-deficient mice.

We examined the role of B-1 cells in protection against Toxoplasma gondii infection using B cell-deficient mice (muMT mice). We found that primed but not naïve B-1 cells from wild-type C57BL/6 mice protected B cell-deficient recipients from challenge infection. All muMT mice transferred with primed B-1 cells survived more than 5 months after T. gondii infection, whereas 100% of muMT mice transferred with naïve B-1 cells succumbed by 18 days after infection. Additionally, high expression of both T help (Th) 1- and Th2-type cytokines and a high level of nitric oxide production were observed in T. gondii-infected muMT mice transferred with primed B-1 cells. Thus, it was clearly demonstrated that B-1 cells play an important role in host protection against T. gondii infection in muMT mice.

Induction of protective immunity by DNA vaccination with Toxoplasma gondii HSP70, HSP30 and SAG1 genes.

The vaccination with Toxoplasma gondii heat shock protein 70 (T.g.HSP70) gene (a virulent tachyzoite-specific) induced the most prominent reduction in T. gondii loads in various organs of B6 and BALB/c mice at the acute and chronic phases of toxoplasmosis compared with T.g.HSP30 (a bradyzoite-specific) and SAG1 (a tachyzoite-specific) genes. A single gene gun vaccination with 2 microg of T.g.HSP70 gene induced a significant reduction in the number of T. gondii organisms compared with 50 microg of T.g.HSP70 gene vaccination by intramuscular (i.m.) or intraperitoneal (i.p.) injection. The vaccine effects of T.g.HSP70 gene persisted for more than 3 months.