Crimean-Congo hemorrhagic fever virus antibody prevalence in Mauritanian livestock (cattle,goats, sheep and camels) is stratified by the animal’s age

Crimean-Congo hemorrhagic fever virus (CCHFV) is one of the most widespread zoonotic arthropod-borne viruses in many parts of Africa, Europe and Asia. It belongs to the family of Nairoviridae in the genus of Orthonairovirus. The main reservoir and vector are ticks of the genus Hyalomma. Livestock animals (such as cattle, small ruminants and camels) develop a viremias lasting up to two weeks with absence of clinical symptoms, followed by seroconversion. This study was carried out to assess risk factors that affect seroprevalence rates in different species. In total, 928 livestock animal samples (cattle = 201; sheep = 247; goats = 233; camels = 247) from 11 out of 13 regions in Mauritania were assayed for CCHFV-specific immunoglobulin G (IgG) antibodies using enzyme-linked immunosorbent assays (ELISA) (including a novel indirect camel-IgG-specific CCHFV ELISA). Inconclusive results were resolved by an immunofluorescence assay (IFA). A generalized linear mixed-effects model (GLMM) was used to draw conclusions about the impact of certain factors (age, species, sex and region) which might have influenced the CCHFV antibody status of surveyed animals. In goats and sheep, about 15% of the animals were seropositive, whereas in cattle (69%) and camels (81%), the prevalence rate was significantly higher. On average, cattle and camels were up to twice to four times older than small ruminants. Interestingly, the seroprevalence in all species was directly linked to the age of the animals, i.e. older animals had significantly higher seroprevalence rates than younger animals. The highest CCHFV seroprevalence in Mauritania was found in camels and cattle, followed by small ruminants. The large proportion of positive animals in cattle and camels might be explained by the high ages of the animals. Future CCHFV prevalence studies should at least consider the age of surveyed animals in order to avoid misinterpretations.     

The SCF-FBXW5 E3-ubiquitin ligase is regulated by PLK4 and targets HsSAS-6 to control centrosome duplication

Deregulated centrosome duplication can result in genetic instability and contribute to tumorigenesis. Here, we show that centrosome duplication is regulated by the activity of an E3-ubiquitin ligase that employs the F-box protein FBXW5 (ref. 3) as its targeting subunit. Depletion of endogenous FBXW5 or overexpression of an F-box-deleted mutant version results in centrosome overduplication and formation of multipolar spindles. We identify the centriolar protein HsSAS-6 (refs 4,5) as a critical substrate of the SCF-FBXW5 complex. FBXW5 binds HsSAS-6 and promotes its ubiquitylation in vivo. The activity of SCF-FBXW5 is in turn negatively regulated by Polo-like kinase 4 (PLK4), which phosphorylates FBXW5 at Ser 151 to suppress its ability to ubiquitylate HsSAS-6. FBXW5 is a cell-cycle-regulated protein with expression levels peaking at the G1/S transition. We show that FBXW5 levels are controlled by the anaphase-promoting (APC/C) complex, which targets FBXW5 for degradation during mitosis and G1, thereby helping to reset the centrosome duplication machinery. In summary, we show that a cell-cycle-regulated SCF complex is regulated by the kinase PLK4, and that this in turn restricts centrosome re-duplication through degradation of the centriolar protein HsSAS-6.     

Cordeauxia edulis and Rhododendron tomentosum extracts disturb orientation and feeding behavior of Hylobius abietis and Phyllodecta laticollis

The use of plant‐based compounds to control insect pests is an alternative to the use of synthetic pesticides. We evaluated the repellent and antifeedant effects of Cordeauxia edulis Hemsley (Fabaceae) and Rhododendron tomentosum Harmaja (Ericaceae) extracts against Hylobius abietis L. (Coleoptera: Curculionidae) and Phyllodecta laticollis Suffrian (Coleoptera: Chrysomelidae). Repellent properties were evaluated by monitoring responses of adult insects toward the odor from extracts or extraction solvents (controls) in a Y‐tube olfactometer, and choice or no‐choice feeding tests were conducted by applying extracts or extraction solvents on stems of Scots pine [Pinus sylvestris L. (Pinaceae)] and European aspen [Populus tremula L. (Salicaceae)], host plants of H. abietis and P. laticollis, respectively. Extracts of R. tomentosum repelled adults of both insect species effectively. However, extracts of C. edulis did not repel H. abietis although its ethyl acetate extract showed repellence against the adults of P. laticollis. Feeding by H. abietis was significantly reduced by a methanol extract of C. edulis, and methanol and hexane extracts of R. tomentosum. Feeding by the adults and larvae of P. laticollis was significantly reduced by extracts from both plant species. Concomitant with less feeding, larval growth was retarded by ethyl acetate extracts of both plant species. Gas chromatography‐mass spectrometry analyses of the volatile components of the extracts showed that extracts from both plant species were mixtures of various terpene and non‐terpene compounds, which showed quantitative and/or qualitative variations between plant species and extraction solvents. This experiment showed that extracts from both plant species effectively manipulated the orientation and/or feeding behavior of the two beetle species. Hence, they may be considered as potential alternatives to synthetic chemical pesticides.     

Geographical distribution and chorology of grasses in the Arabian Peninsula

Arid regions of Saudi Arabia occupy most of the area of the Arabian Peninsula. These areas are at the meeting position of plants from Mediterranean, Irano-Turanian, Saharo-Arabian, and Sudanian phytogegraphical regions. Geomorphology of the area reveals a wide diversity of landforms including coastal lines, desert plains, and high mountains. Grasses are well represented in the flora of Saudi Arabia and form an appropriate group for studying the relation of grass distribution, chorology, and photosynthetic pathways. In this paper, geographical distribution of C₃ and C₄ grasses was studied in an area extending between latitude 17°N and latitude 31°N. Two regions were recognized in the study area, namely; a (relatively) cold region north of latitude 24°N with ample winter rainfall, and a hot region south of latitude 24°N with scarce summer rainfall. Work involved field observations and collection of grass species in the study area. Work also depended on published carbon discrimination values of grasses and biochemical analysis of C₄ species subtypes. Climatic conditions in the study area vary considerably, and the distribution of grass species was found to follow patterns that reveal adaptive advantages of different photosynthetic pathways. Grass species in the cold northern region with ample winter rainfall are generally C₃ grasses belonging mainly to Mediterranean/Irano-Turanean chorotypes. C₃ grass species found in the southern hot region were recorded at high altitudes of southern mountains characterized by low temperatures. Grass species recorded at low altitudes in the south hot region with scarce summer rainfall were mainly C₄ grasses belonging to Tropical and Saharo-Arabian-Sudanean chorotypes. Pronounced spatial variations of temperature profoundly control the geographical distribution of C₃ and C₄ grasses. Low temperatures in the northern cold region and at high altitudes of the southern hot region limit the occurrence of C₄ grasses and shift the ecological balance in favor of C₃ grasses. Results are discussed in terms of heat sensitivity of the CO₂ carboxylating enzyme of C₃ grasses and high temperature optima for CO₂ assimilation of C₄ grasses. Results are also discussed in comparison with geographical distribution of grasses in other parts of the world.     

Increased Markers of Oxidative Stress in Autistic Children of the Sultanate of Oman

Autism spectrum disorder (ASD) is a neurodevelopmental disorder of early childhood, and an enumeration about its etiology and consequences is still limited. Oxidative stress-induced mechanisms are believed to be the major cause for ASD. In this study 19 autistic and 19 age-matched normal Omani children were recruited to analyze their degree of redox status and a prewritten consent was obtained. Blood was withdrawn from subjects in heparin-coated tube, and plasma was separated. Plasma oxidative stress indicators such as nitric oxide (NO), malondialdehyde (MDA), protein carbonyl, and lactate to pyruvate ratio were quantified using commercially available kits. A significant elevation was observed in the levels of NO, MDA, protein carbonyl, and lactate to pyruvate ratio in the plasma of Omani autistic children as compared to their age-matched controls. These oxidative stress markers are strongly associated with major cellular injury and manifest severe mitochondrial dysfunction in autistic pathology. Our results also suggest that oxidative stress might be involved in the pathogenesis of ASD, and these parameters could be considered as diagnostic markers to ensure the prevalence of ASD in Omani children. However, the oxidative stress-induced molecular mechanisms in ASD should be studied in detail.     

Change in composition of the Anopheles gambiae complex and its possible implications for the transmission of malaria and lymphatic filariasis in north-eastern Tanzania

ABSTRACT: BACKGROUND: A dramatic decline in the incidence of malaria due to Plasmodium falciparum infection in coastal East Africa has recently been reported to be paralleled (or even preceded) by an equally dramatic decline in malaria vector density, despite absence of organized vector control. As part of investigations into possible causes for the change in vector population density, the present study analysed the Anopheles gambiae s.l. sibling species composition in north-eastern Tanzania. METHODS: The study was in two parts. The first compared current species complex composition in freshly caught An. gambiae s.l. complex from three villages to the composition reported from previous studies carried out 2-4 decades ago in the same villages. The second took advantage of a sample of archived dried An. gambiae s.l. complex specimens collected regularly from a fourth study village since 2005. Both fresh and archived dried specimens were identified to sibling species of the An. gambiae s.l. complex by PCR. The same specimens were moreover examined for Plasmodium falciparum and Wuchereria bancrofti infection by PCR. RESULTS: As in earlier studies, An. gambiae s.s., Anopheles merus and Anopheles arabiensis were identified as sibling species found in the area. However, both study parts indicated a marked change in sibling species composition over time. From being by far the most abundant in the past An. gambiae s.s. was now the most rare, whereas An. arabiensis had changed from being the most rare to the most common. P. falciparum infection was rarely detected in the examined specimens (and only in An. arabiensis) whereas W. bancrofti infection was prevalent and detected in all three sibling species. CONCLUSION: The study indicates that a major shift in An. gambiae s.l. sibling species composition has taken place in the study area in recent years. Combined with the earlier reported decline in overall malaria vector density, the study suggests that this decline has been most marked for An. gambiae s.s., and least for An. arabiensis, leading to current predominance of the latter. Due to differences in biology and vectorial capacity of the An. gambiae s.l. complex the change in sibling species composition will have important implications for the epidemiology and control of malaria and lymphatic filariasis in the study area.     

Hexavalent chromate reduction by alkaliphilic Amphibacillus sp. KSUCr3 is mediated by copper-dependent membrane-associated Cr(VI) reductase

The present study was aimed to localize and characterize hexavalent chromate [Cr(VI)] reductase activity of the extreme alkaliphilic Amphibacillus sp. KSUCr3 (optimal growth pH 10.5). The resting cells were able to reduce about 62 % of the toxic heavy metal Cr(VI) at initial concentration of 200 μM within 30 min. Cell permeabilization resulted in decrease of Cr(VI) reduction in comparison to untreated cells. Enzymatic assays of different sub-cellular fractions of Amphibacillus sp. KSUCr3 demonstrated that the Cr(VI) reductase was mainly associated with the membranous fraction and expressed constitutively. In vitro studies of the crude enzyme indicated that copper ion was essential for Cr(VI) reductase activity. In addition, Ca2? and Mn2? slightly stimulated the chromate reductase activity. Glucose was the best external electron donor, showing enhancement of the enzyme activity by about 3.5-fold. The K (m) and V (max) determined for chromate reductase activity in the membranous fraction were 23.8 μM Cr(VI) and 72 μmol/min/mg of protein, respectively. Cr(VI) reductase activity was maximum at 40 °C and pH 7.0 and it was significantly inhibited in the presence of disulfide reducers (2-mercaptoethanol), ion chelating agent (EDTA), and respiratory inhibitors (CN and Azide). Complete reduction of 100 and 200 μM of Cr(VI) by membrane associated enzyme were observed within 40 and 180 min, respectively. However, it should be noted that biochemical characterization has been done with crude enzyme only, and that final conclusion can only be drawn with the purified enzyme.     

Phenotyping of circulating CD8⁺ T cell subsets in human cutaneous leishmaniasis

Recovery from CL is usually accompanied with long-lasting protection and induction of strong immune response. The phenotypes, generation and maintenance of central (=T_CM) and effector (=T_EM) memory T cell subsets in human leishmaniasis are not well known. Profile of T cell subsets were analyzed on peripheral CD8⁺ T cells from volunteers with history of cutaneous leishmaniasis (HCL).In HCL and control groups, mean frequencies of CCR7⁺CD45RA⁺CD8⁺ naïve and CCR7^?CD45RA^?CD8⁺ T_EM cells were higher than other subsets before culture, but after stimulation with soluble Leishmania antigen, the frequency of naïve T cells was significantly decreased and the frequency of T_EM cells was significantly increased. T_EM phenotype composed the highest portion of proliferating Carboxy Fluorescein diacetate Succinimidyl Ester (CFSE)-dim population which was significantly higher in HCL volunteers than in control group. Stimulation of isolated CD8⁺ memory T cells, but not naïve T cells, from HCL volunteers induced a significantly higher IFN-γ production compared with that of healthy controls. Intracellular IFN-γ staining provided the same result.Memory population is shown to be responsible for Leishmania-induced IFN-γ production. Leishmania-reactive proliferating T_EM cells were identified as the most frequent subset which may play a role in recall immune response and protection against Leishmania infection.     

A novel chimeric influenza virosome containing <Emphasis Type="Italic">Vesicular stomatitis</Emphasis> G protein as a more efficient gene delivery system

Objectives

To enhance the efficiency of influenza virosome-mediated gene delivery by engineering this virosome.

Results

A novel chimeric influenza virosome was constructed containing the glycoprotein of Vesicular stomatitis virus (VSV-G), along with its own hemagglutinin protein. To optimize the transfection efficiency of both chimeric and influenza cationic virosomes, HEK cells were transfected with plasmid DNA and virosomes and the transfection efficiency was assessed by FACS analysis. The chimeric virosome was significantly more efficient in mediating transfection for all amounts of DNA and virosomes compared to the influenza virosome.

Conclusions

Chimeric influenza virosome, including VSV-G, is superior to the conventional influenza virosome for gene delivery.