Influence of temperature and salinity on the viability and infectivity of giardia lamblia and cryptosporidia parvum

The present work was designed to assess the effect of different degrees of temperature and salinity on the viability and infectivity of G. Lamblia and C. parvum at different storage times. The results revealed that boiling of protozoa for one minute minimized their viability to less than 1% and rendered them noninfectious, while the exposure to 4C and -4C up to seven days preserved their viability and infectivity. Whereas, it was found that salinity was effective at a high concentration [50 ppt] for a long storage time at lower concentrations

Detection of trichomoniasis in vaginal specimens by both conventional and modern molechlar tools

The aim of this study was to compare the use of wet mount, modified Diamonds media, acridine orange [AO] stain and PCR tools in the diagnosis of T. vaginalis in females. Out of 23 symptomatic cases, 21 specimens were positive for T. Vaginalis by one or more methods. Twenty-one were positive by PCR and 17 by culture, 14 by AO stain and 13 by wet mount microscopy. The PCR detected all the positive cases and no PCR negative cases proved to be positive by any other technique. So, PCR is considered the test of choice for the diagnosis of trichomoniasis. The modified Diamonds media proved to be highly sensitive and the results of the culture were significantly associated with those of PCR. The results of both wet mount and AO stain were insignificantly associated. Although wet mount is widely used, easy, rapid and inexpensive, yet it has a low sensitivity. So, negative cases should be repeated by either culture or PCR

Effect of topical agents on cercariae of schistosoma mansoni

The present work was planed to evaluate the effect of free N, N- diethyl-m- toluamide [DEET], controlled release DEET and white precipitate ointment on the viability of cercariae of S. mansoni in vitro. They were also topically applied to mice to study their efficiency in preventing cercarial skin penetration. Free DEET and controlled release DEET formula caused immobilization and death of cercariae within 20 and 5 min, respectively. The number of adults detected after the application of free DEET and white precipitate ointment to mice skin prior to infection were significantly lower than the control group. When controlled release DEET was applied, no adults could be detected, indicating the failure of cercariae to enter through the skin. This was confirmed by histopathological study of the liver which was free of granuloma. Scanning electron microscopy revealed tegumental changes in cercariae exposed to both free DEET and controlled released DEET. So, topical application of any of the three chemicals was found to be effective in controlling S. mansoni infection. The best was with controlled release DEET

Vaccination against congenital toxoplasmosis

Different types of Toxoplasma gondii vaccines were evaluated using parasitological and histopathological means to induce immunity in Swiss pregnant mice and their pups against the challenge with virulent RH strain. Immunization was performed before mating by using live cyst vaccines [LCV], LCV-IL-2 combination, irradiated cyst vaccine [ICV] and ICV-IL-2 combination. It was demonstrated that pre- immunization with the current vaccines offered a significant protection of both dams and pups. The highest level of protection was noticed in mice received LCV-IL2, followed by ICV-IL-2, then LCV and the least protection was elicited in dams immunized with ICV alone. The results revealed the possibility of applying such accines, not only in mice but also in other mammalian hosts including humans

Human pathogenic protozoa in bivalves collected from local markets in Alexandria

Bivalves are filter feeders concentrating pathogens from waters and are often eaten raw. Two species, Caelatura iaronia pruneri and Donax trunculus limiacus, commonly known as Gandofli and Om El-Kholool, respectively, were examined. Shellfish were collected from markets in Alexandria to detect any human pathogenic protozoa in them. The infectivity of the detected protozoa was studied by experimental animal inoculation. The results revealed the presence of infectious Cryptosporidia oocysts and Microsporidia spores in both bivalves. Cyclospora sp. was detected only in Gandofli, but was noninfectious to mice. There is a potential risk of acquiring protozoa infections if shellfish are eaten raw or insufficiently cooked

newapproach in cultivation of leishmania major using human urine

Serum-free media have been devised for several Leishmania species, yet they tend to be complex and not particularly cheap. In the present work 5% healthy human urine was tried as a supplement to RPMI-1640 basal medium and was compared to 10% fetal calf serum. It greatly aided the growth of L.major invitro, and its maintenance for seven subcultures with five days interval. Infectivity of promastigotes was then tested by inoculation into mice. The lesion was similar in onset, duration and severity to the control group. However the urine-supplemented medium was unsuccessful for primary isolation of Leishmania from infected mice

Morphology, histochemistry and infectivity of blastocystis hominis cyst

Different morphological forms of Blastocystis hominis were identified in human stool samples including both cystic and trophic stages. The latter was induced to encyst by keeping them in potassium dichromate solution for two weeks. Suspected of being the infective stage, cysts were studied in more detail as regards their morphology using both light and electron microscopy. Histochemistry and infectivity studies were also carried out