Report on eight weeks at the Fisheries Department of the Lancashire River Authority [including a Leeds / Liverpool Canal survey]

This report looks at the interests of the Fisheries Department for the Lancashire River Board, focusing on the Liverpool and Leeds Canal Survey. It looks at finding parasites in fish from an electrofishing survey (roach and perch). This was to contribute towards the main survey with a possible view to suggesting whether or not the parasites were one reason for the poor fish population. Methods of finding parasites are given, and results of what parasites that were found in the fish are discussed

New synchronization method for <i>Plasmodium falciparum</i>

&lt;b&gt;Background&lt;/b&gt;: Plasmodium falciparum is usually asynchronous during in vitro culture. Although various synchronization methods are available, they are not able to narrow the range of ages of parasites. A newly developed method is described that allows synchronization of parasites to produce cultures with an age range as low as 30 minutes. &lt;b&gt;Methods&lt;/b&gt;: Trophozoites and schizonts are enriched using Plasmion. The enriched late stage parasites are immobilized as a monolayer onto plastic Petri dishes using concanavalin A. Uninfected erythrocytes are placed onto the monolayer for a limited time period, during which time schizonts on the monolayer rupture and the released merozoites invade the fresh erythrocytes. The overlay is then taken off into a culture flask, resulting in a highly synchronized population of parasites. &lt;b&gt;Results&lt;/b&gt;: Plasmion treatment results in a 10- to 13-fold enrichment of late stage parasites. The monolayer method results in highly synchronized cultures of parasites where invasion has occurred within a very limited time window, which can be as low as 30 minutes. The method is simple, requiring no specialized equipment and relatively cheap reagents. &lt;b&gt;Conclusions&lt;/b&gt;: The new method for parasite synchronization results in highly synchronized populations of parasites, which will be useful for studies of the parasite asexual cell cycle

Branching Feller diffusion for cell division with parasite infection

We describe the evolution of the quantity of parasites in a population of cells which divide in continuous-time. The quantity of parasites in a cell follows a Feller diffusion, which is splitted randomly between the two daughter cells when a division occurs. The cell division rate may depend on the quantity of parasites inside the cell and we are interested in the cases of constant or monotone division rate. We first determine the asymptotic behavior of the quantity of parasites in a cell line, which follows a Feller diffusion with multiplicative jumps. We then consider the evolution of the infection of the cell population and give criteria to determine whether the proportion of infected cells goes to zero (recovery) or if a positive proportion of cells becomes largely infected (proliferation of parasites inside the cells)

Prevalence of intestinal parasitic infections among university female students, Gaza, Palestine

The intestinal parasites are still endemic among children, women, and men in Gaza Strip. To the best of our knowledge, this is the first study of intestinal parasites among young female students of Islamic University of Gaza to report the existence and prevalence of intestinal parasites. A total of 305 stool samples were collected from female students in all faculties and were examined by wet mount and formal ether sedimentation technique. This study showed that the overall prevalence of intestinal parasites was 20.6%. The detected intestinal parasites were as follows: (7.5%), (4.9%), (0.3%), (2.6%), (1.0%), and (3.9%). Science students showed the highest prevalence for parasitic infections (35.3%), and married students (16.7%) had higher prevalence than single students (6.5%). It was concluded that female students also are under risk of gaining parasitic infection in spite of their education. It is recommended that university students should be subjected to regular medical examinations for parasitic infections. [Abstract copyright: Copyright: © 2019 Avicenna Journal of Medicine.

Fluorescent Plasmodium berghei sporozoites and pre-erythrocytic stages: a new tool to study mosquito and mammalian host interactions with malaria parasites.

To track malaria parasites for biological studies within the mosquito and mammalian hosts, we constructed a stably transformed clonal line of Plasmodium berghei, PbFluspo, in which sporogonic and pre-erythrocytic liver-stage parasites are autonomously fluorescent. A cassette containing the structural gene for the FACS-adapted green fluorescent protein mutant 2 (GFPmut2), expressed from the 5' and 3' flanking sequences of the circumsporozoite (CS) protein gene, was integrated and expressed at the endogenous CS locus. Recombinant parasites, which bear a wild-type copy of CS, generated highly fluorescent oocysts and sporozoites that invaded mosquito salivary glands and were transmitted normally to rodent hosts. The parasites infected cultured hepatocytes in vitro, where they developed into fluorescent pre-erythrocytic forms. Mammalian cells infected by these parasites can be separated from non-infected cells by fluorescence activated cell sorter (FACS) analysis. These fluorescent insect and mammalian stages of P. berghei should be useful for phenotypic studies in their respective hosts, as well as for identification of new genes expressed in these parasite stages

Effects of Ostertagia circumcincta larvae and adult parasites on abomasal and intestinal tissues in sheep : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Physiology

Ostertagia circumcincta parasites infect the abomasum of sheep causing damage to the abomasal tissues and significant production losses to the sheep farming industry. Ingested larvae enter the gastric glands and emerge as adults which live in the abomasal lumen. The effect of adult parasites on the abomasum has not been systematically investigated. In the present study, sheep raised to be free of helminth parasites were given either adult O. circumcincta parasites via an abomasal cannula or larvae per os. Adult as well as larval O. circumcincta parasites stimulate hypergastrinaemia, a decreased abomasal pH and elevated serum pepsinogen concentrations. While the concentration of G cells did not change in the larval parasite infected sheep compared with the non-infected control sheep, the total number of G cells was increased due to an increase in mucosal thickness. There appeared to be fewer G cells present in the adult parasite infected sheep compared with the non-infected control sheep, which was most likely due to a depletion of their gastrin content due to overstimulation. The hypergastrinaemia observed during ostertagiasis is not due to a change in the ratio of G:D cells. The lumen dwelling adult O. circumcincta affect the mucosa of the abomasum resulting in an apparent inflammatory reaction, demonstrated by the presence of eosinophils and neutrophils in the lamina propria. Mucous production and/or secretion is also affected, shown by the presence of large mucus-secreting cells in the mucosa. The total wet weight of the abomasum/kg body weight is increased in sheep infected with O. circumcincta, with an increase in the total size of the abomasum. The larval parasites evoke a hyperplasia in both the antral and body mucosae with little change in cell size. In sheep infected with adult parasites, the thickness of the abomasal mucosa is increased in the body, but not the antrum. This increase is most likely due to hypertrophy. Either the larval O. circumcincta or the hypergastrinaemia have trophic effects on the upper duodenum, with an increased mucosal thickness which did not occur more distally. This did not occur in the adult parasite infected sheep. The larval parasites or hypergastrinaemia provoked a hyperplasia in the jejunal mucosa. This did not occur in the adult infected sheep. The larvae and adult parasites did not appear to exert a hypertrophic or hyperplastic effect on the ileum, caecum or colon. Those results indicate that adult O. circumcincta parasites have substantial effects on the ovine abomasum