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Entamoeba histolytica infection causes amoebiasis, which is a global public health problem. The major route of infection is oral ingestion of E. histolytica cysts, cysts being the sole form responsible for host-to-host transmission. Cysts are produced by cell differentiation from proliferative trophozoites in a process termed ‘encystation’. Therefore, encystation is an important process from a medical as well as a biological perspective. Previous electron microscopy studies have shown the ultrastructure of precysts and mature cysts; however, the dynamics of ultrastructural changes during encystation were ambiguous. Here, we analysed a series of Entamoeba invadens encysting cells by transmission electron microscopy. Entamoeba invadens is a model for encystation and the cells were prepared by short interval time course sampling from in vitro encystation-inducing cultures. We related sampled cells to stage conversion, which was monitored in the overall population by flow cytometry. The present approach revealed the dynamics of ultrastructure changes during E. invadens encystation. Importantly, the results indicate a functional linkage of processes that are crucial in encystation, such as glycogen accumulation and cyst wall formation. Hence, this study provides a reference for studying sequential molecular events during Entamoeba encystation.

Background: Hydatidosis is an infection caused by the cystic larval stage of Echinococcus granulosus. This disease is a zoonotic disease has a worldwide distribution and common in developing and undeveloped countries. Objectives: The objective of the present study is to studying the infection rate and predilection seats of hydatid cyst affections among slaughtered food animals in Aswan Governorate, southern Egypt and study the effect of age and sex of infected slaughtered animals on the infection with hydatid cyst. Also, study the effect of seasonal variations in the infection with hydatid cyst among slaughtered animals. In addition, the macroscopic examination, microscopic examination, scanning electron microscopy and histopathological studies for the collected hydatid cyst are examined. Methods: This investigation was carried out from August 2015 to July 2016 in two main slaughterhouses in Aswan Governorate to study the hydatidosis in camels and sheep. By routine meat inspection, hydatid cyst count and characterization was conducted. Findings: A total of 2080 camels and 674 sheep were examined. Of these, 173 (8.32%) camels and 3 (0.45%) sheep were found to harbour one or more hydatid cysts. Female and older age slaughtered animals were more susceptible to infection with these metacestode than males and younger animals. Hydatid cyst infection in slaughtered animals is most commonly found in lung followed by liver while mixed infection in both lung and liver was found only in camel. Hydatid cyst in slaughtered camels was higher in autumn followed by winter, while hydatid cyst in slaughtered sheep was found only in autumn season. Fertile cysts in lung and liver of slaughtered camels was 83.4% and 30% respectively. While the fertility of hydatid cyst in infected lung and liver of sheep was 100%. Main conclusions: This study reported that slaughtered animals were infected with relatively high infection rate of hydatid cyst may be due to the presence of socio-economic conditions favourable for the disease and maintenance of high level of infection. So must design governmental control programs against hydatidosis to minimize the infection rate in Aswan Governorate and ensure effective protection not only for animal population but also for humans at risk of contracting the infection.

Giardiasis is an intestinal protozoal disease caused by Giardia lamblia. The disease became a global health issue due to development of resistance to commonly used drugs. Since many plant-derived products have been used to treat many parasitic infestations, we aimed to assess the therapeutic utility of Artemisia annua (A. annua) for giardiasis. We showed that NO production was significantly reduced whereas serum levels of IL-6, IFN-γ, and TNF-α were elevated in infected hamsters compared to uninfected ones. Additionally, infection resulted in increased numbers of intraepithelial lymphocytes and reduced villi heights, goblet cell numbers, and muscularis externa thickness. We also showed that inducible NO synthase (iNOS) and caspase-3 were elevated in the intestine of infected animals. However, treatment with A. annua significantly reduced the intestinal trophozoite counts and IEL numbers, serum IL-6, IFN-γ, and TNF-α, while increasing NO and restoring villi heights, GC numbers, and ME thickness. Moreover, A. annua treatment resulted in lower levels of caspase-3, which indicates a protective effect from apoptotic cell death. Interestingly, A. annua therapeutic effects are comparable to metronidazole. In conclusion, our results show that A. annua extract is effective in alleviating infection-induced intestinal inflammation and pathological effects, which implies its potential therapeutic utility in controlling giardiasis.

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