Structural analysis of the SRP Alu domain from Plasmodium falciparum reveals a non-canonical open conformation

The eukaryotic signal recognition particle (SRP) contains an Alu domain, which docks into the factor binding site of translating ribosomes and confers translation retardation. The canonical Alu domain consists of the SRP9/14 protein heterodimer and a tRNA-like folded Alu RNA that adopts a strictly ‘closed’ conformation involving a loop-loop pseudoknot. Here, we study the structure of the Alu domain from Plasmodium falciparum (PfAlu), a divergent apicomplexan protozoan that causes human malaria. Using NMR, SAXS and cryo-EM analyses, we show that, in contrast to its prokaryotic and eukaryotic counterparts, the PfAlu domain adopts an ‘open’ Y-shaped conformation. We show that cytoplasmic P. falciparum ribosomes are non-discriminative and recognize both the open PfAlu and closed human Alu domains with nanomolar affinity. In contrast, human ribosomes do not provide high affinity binding sites for either of the Alu domains. Our analyses extend the structural database of Alu domains to the protozoan species and reveal species-specific differences in the recognition of SRP Alu domains by ribosomes.

FORMATION OF BIODIVERSITY OF THE FAUNA OF ECTO- AND ENDOPARASITES ON THE ARARAT PLAIN OF ARMENIA

Our studies were aimed at analyzing biodiversity of ecto- and endoparasites of sheep, cattle, rabbits, domestic birds and dogs in the lowland zone of the Republic, with semidesert climate and height of 850 m above the sea level. This is one of the warm regions of the Republic. The studies performed have established moderate and high degree of animal infection with parasites. We identified 33 parasite species, mostly helminths (15 species), including 10 species of nematodes (Trichocephalus ovis, Nematodirus spathiger, Haemonchus contortus, Chabertia ovina, Dictyocaulus filaria, Muellerius capillaris, Protostrongylus spp., Passalurus ambiqus, Ascaridia galli, Heterakis gallinarum), 4 species of trematodes (Fasciola hepatica, F. gigantica, Dicrocoelium dendriticum, Paramphistomum cervi), 1 species of cestodes (Moniezia expansa), 9 protozoan species (Piroplasma bigeminum, Babesia ovis, Eimeria perforans, E. magna, E. irresidua, E. tenella, E. acervulina), 7 species of ticks, 1 species of insects, and 1 species of leishmaniasis vector, the mosquitos from the genus Phlebotomus. We registered 5 species of freshwater molluscs (Lymnaea auricularia, L. stagnalis, L. ovata, L. truncatula, Planorbis planorbis), and 2 species of terrestrial molluscs (Helicella derbentina, Napaeopsis hohenackeri).

Review on Boosting up Body’s Natural Defence Mechanism and Suppression of Symptoms against SARS-CoV-2 (Covid-19)

The prevailing global health crisis, posed by the pandemic COVID-19, has threatened the livelihood of the public around the world. The dramatic coronavirus surge (2019-nCoV) is denoted as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Initially, this deadly ailment was identified to have originated from bats and thereafter, passed on to human beings, in December 2019 via unknown modes of biological transmission in Wuhan, China. One of the leading causes of COVID-19 mortality could be attributed to respiratory failure (hypoxemic or hypercapnic) due to acute respiratory distress. From an immunological perspective, the virus triggers secondary haemophagocytic lymphohistiocytosis, which results in fulminant, followed by fatal hypercytokinaemia alongside multiple organ failure, which happens in adults, in most of the predominant cases. As several scientific communities and researchers, tirelessly strive to find a suitable cure since there is a need for finding a registered medication/vaccine against COVID-19, it becomes quite pertinent for boosting our immune system. As the immune system, supports the body’s ability, as a fortress, to defend against pathogenic microbes, comprising of viruses, fungi, bacteria and protozoan species, thereby restricting infection. This review emphasizes the utilization of naturally-derived or otherwise plant-based supplements/foods that facilitate in enhancing or boosting the immunity against COVID-19, irrespective of one’s age. For a healthy lifestyle, the use of micro and macronutrients, such as: magnesium, zinc, vitamin-rich foods, especially vitamins C, D and E, since health could be enhanced and an individual could be further aided to overcome the infection. This report, majorly investigates the significance of antioxidants and their roles as immune boosters, through determining the various vitamins C and D-rich compounds, alongside the various secondary metabolites-endowed foods from various sources, which could most likely facilitate in improving immunity and thereby, controlling COVID-19.

Frequency of intestinal parasites in patients attended at a university hospital in Maceió, state of Alagoas, Brazil

The aim of this study was to analyze the parasitological tests of a population at a public hospital in Maceió-AL. A descriptive study was made between January and July of 2015 analyzing the parasitological tests of a population at a public hospital in Maceió-AL. Variables such as gender, age, positive tests, protozoan species, helminths species and parasitic associations were analyzed. Out of 1.581 tests, 806 (51%) tested positive. Regarding gender, 535 (67%) were from women. Helminths were the most predominant infections (63.94%), compared to protozoans (36.06%). The Helminths with the highest number of infections were: Ascaris lumbricoides (93.23%), Trichuris trichiura (2.32%) and Enterobius vermicularis (1.26%). Among protozoans, Endolimax nana and Entamoeba coli corresponded to 78.09% and 15.91% respectively. Although non pathogenic, it suggests fecal contamination. According to the degree of parasitism, 84.0% were monoparasitism. It can be concluded that the number of positive tests for enteroparasites was high, mainly in men. The species A. lumbricoides was the main helminth detected, while E. nana was the main protozoan found in the tests. The age group between 24 and 59 years old was the one that had the highest amount of positive tests. The results observed strengthen the need for the implementation of prevention measures for intestinal parasitic infections.

THE FIRST STUDY OF THE ENDOPARASITIC FAUNA OF MUTE SWANS (CYGNUS OLOR) IN THE NORTHERN PART OF SERBIA

In the Northern part of Serbia, which is part of Pannonian Basin, mute swan (Cygnus olor) population has notably increased over the last few decades. Like other birds from Anatidae family, mute swans are a host of numerous endoparasite species. The aim of this study was to acquire the data on identification and prevalence of endoparasites in mute swans in the Republic of Serbia, as that information is lacking. Individual faecal samples of sixty-eight adult mute swans were examined for the presence of endoparasites. Coprological examination was performed using flotation and sedimentation technique with saturated ZnSO4 solution. The samples were collected from December 2016 to March 2017, during epizootic of highly pathogenic avian influenza H5N8 in the Republic of Serbia. Dead mute swans were collected from twelve different locations in the Northern part of Serbia. Altogether, 39.7% of the examined fecal samples contained different parasites. The endoparasitic fauna was divers and included 3 species of nematodes, 2 cestodes species, one trematode and one protozoan species. Nematodes were the most prevalent helminthes and among these the most frequent nematode species found was Heterakis dispar (17.6%), followed by Echinuria uncinata (5,8%) and Ascaridia spp. (4,4%). Four mixed infections were found, where double infection was the most prevalent. No endoparasites were found in faecal samples of mute swans collected from the locations Sombor and Titel. As this study covers a small population of mute swans, more detailed studies need to be carried out on a larger population in order to gain an insight into the diversity and prevalence of endoparasites in the Republic of Serbia.

Gastrointestinal parasites of a population of emus (Dromaius novaehollandiae) in Brazil

Emus are large flightless birds in the ratite group and are native to Australia. Since the mid-1980s, there has been increased interest in the captive breeding of emus for the production of leather, meat and oil. The aim of this study was to identify gastrointestinal parasites in the feces of emus Dromaius novaehollandiae from a South American scientific breeding. Fecal samples collected from 13 birds were examined by direct smears, both with and without centrifugation, as well as by the fecal flotation technique using Sheather’s sugar solution. Trophozoites, cysts and oocysts of protozoa and nematode eggs were morphologically and morphometrically evaluated. Molecular analysis using PCR assays with specific primers for the genera Entamoeba, Giardia and Cryptosporidium were performed. Trophozoites and cysts of Entamoeba spp. and Giardia spp., oocysts of Eimeria spp. and Isospora dromaii, as well as eggs belonging to the Ascaridida order were found in the feces. Three animals were diagnosed with Giardia spp., and three were positive for Entamoeba spp. based on PCR techniques. After analyzing the data, we concluded that emus were infected enzootically by nematode and protozoan species.

Prevalence of Perkinsus spp. in selected shellfish species collected off China coast

We investigated the prevalence of Perkinsus spp. in 13 species of shellfish collected from the coastal areas of China between 2006 and 2012. A total of 11,581 shellfish specimens belonging to 13 different species were collected from seven bay areas in China viz., Dalian (Bohai Sea), Qingdao (Yellow Sea), Wenzhou (East China Sea), Xiamen (East China Sea), Zhanjiang (South China Sea), Haikou (South China Sea) and Qinzhou (South China Sea). The shellfish samples collected were tested for the prevalence of Perkinsus spp. using a PCR protocol. The detection rates of Perkinsus spp. by PCR method ranged from 0.38 to 26.37%, with Ruditapes philippinarum (26.37%) and Paratapes undulatus (=Paphia undulata) (20.21%) showing the highest detection rate. The detection rate of Perkinsus spp. by PCR in oyster samples were highest in Wenzhou (17.25%), Qinzhou (15.98%) and Zhanjiang (11.67%) bays. Samples taken in autumn showed the highest positive detection rate. Mixed infection by Perkinsus spp. and other protozoan species viz., Haplosporidium nelsoni and Marteiliia spp. was found to be a common phenomenon (10.75%).

Mucocutaneous Leishmaniasis Mimicking Squamous Cell Carcinoma

Leishmaniasis is a parasitic infectious disease caused by protozoan species belonging to the [...]

Extremely low malaria prevalence in a wetland specialist passerine

Avian malaria (caused by Plasmodium spp.) and avian malaria-like infections (caused by Haemoproteus spp.) are widespread and can seriously affect the health of their bird hosts, especially of immunologically naïve individuals. Therefore, these parasites have long been in the focus of bird-parasite studies. However, the species richness and diversity of these protozoan species have only been revealed since the use of molecular techniques. Diversity and prevalence of these parasites among different bird species and even between populations of a species show a large variation. Here, we investigated prevalence of avian malaria and avian malaria-like parasites in two distant populations of a non-migratory wetland specialist passerine, the bearded reedling (Panurus biarmicus). While previous studies have shown that reed-dwelling bird species often carry various blood parasite lineages and the presence of the vectors transmitting Plasmodium and Haemoproteus species has been confirmed from our study sites, prevalence of these parasites was extremely low in our populations. This may either suggest that bearded reedlings may avoid or quickly clear these infections, or these parasites cause high mortality in this species. The remarkably low prevalence of infection in this species is consistent with earlier studies and makes bearded reedlings a possible model organism for investigating the genetic or behavioural adaptations of parasite resistance.