Ultrastructural data on a microsporidian infesting the ovaries of an araneid

Oligosporidium nov. gen. arachnicolum (Codreanu-B?lcescu, Codreanu and Traciuc, 1978) is one of the more intensively studied microsporidians from an araneid. It develops into parasitophorous vacuoles formed in the oocytes of Xysticus cambridgei from Bucharest, Romania. The uninucleated schizogonic and sporogonic stages multiply through binary fission and the dense bordered sporoblasts give rise to isolated spores.     

Locus-specific chromatin profiling of evolutionarily young transposable elements

Despite a vast expansion in the availability of epigenomic data, our knowledge of the chromatin landscape at interspersed repeats remains highly limited by difficulties in mapping short-read sequencing data to these regions. In particular, little is known about the locus-specific regulation of evolutionarily young transposable elements (TEs), which have been implicated in genome stability, gene regulation and innate immunity in a variety of developmental and disease contexts. Here we propose an approach for generating locus-specific protein–DNA binding profiles at interspersed repeats, which leverages information on the spatial proximity between repetitive and non-repetitive genomic regions. We demonstrate that the combination of HiChIP and a newly developed mapping tool (PAtChER) yields accurate protein enrichment profiles at individual repetitive loci. Using this approach, we reveal previously unappreciated variation in the epigenetic profiles of young TE loci in mouse and human cells. Insights gained using our method will be invaluable for dissecting the molecular determinants of TE regulation and their impact on the genome.     

Virulotyping of <Emphasis Type="Italic">Salmonella enterica</Emphasis> subsp. <Emphasis Type="Italic">enterica</Emphasis> isolated from indigenous vegetables and poultry meat in Malaysia using multiplex-PCR

The increased occurrence of Salmonella occurrence in local indigenous vegetables and poultry meat can be a potential health hazards. This study is aimed to detect the prevalence of twenty different virulence factors among Salmonella enterica strains isolated from poultry and local indigenous vegetables in Malaysia via an optimized, rapid and specific multiplex PCR assay. The assay encompasses a total of 19 Salmonella pathogenicity islands genes and a quorum sensing gene (sdiA) in three multiplex reaction sets. A total of 114 Salmonella enterica isolates belonging to 38 different serovars were tested. Each isolate in under this study was found to possess up to 70% of the virulence genes tested and exhibited variable pathogenicity gene patterns. Reproducibility of the multiplex PCR assay was found to be 100% and the detection limit of the optimized multiplex PCR was tested with lowest detectable concentration of DNA 0.8 pg μl⁻¹. This study demonstrated various Salmonella pathogenicity island virulence gene patterns even within the same serovar. This sets of multiplex PCR system provide a fast and reliable typing approach based on Salmonella pathogenicity islands, thus enabling an effective monitoring of emerging pathogenic Salmonella strains as an additional tool in Salmonella surveillance studies.     

Heterogeneous Occupancy and Density Estimates of the Pathogenic Fungus Batrachochytrium dendrobatidis in Waters of North America

Biodiversity losses are occurring worldwide due to a combination of stressors. For example, by one estimate, 40% of amphibian species are vulnerable to extinction, and disease is one threat to amphibian populations. The emerging infectious disease chytridiomycosis, caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd), is a contributor to amphibian declines worldwide. Bd research has focused on the dynamics of the pathogen in its amphibian hosts, with little emphasis on investigating the dynamics of free-living Bd. Therefore, we investigated patterns of Bd occupancy and density in amphibian habitats using occupancy models, powerful tools for estimating site occupancy and detection probability. Occupancy models have been used to investigate diseases where the focus was on pathogen occurrence in the host. We applied occupancy models to investigate free-living Bd in North American surface waters to determine Bd seasonality, relationships between Bd site occupancy and habitat attributes, and probability of detection from water samples as a function of the number of samples, sample volume, and water quality. We also report on the temporal patterns of Bd density from a 4-year case study of a Bd-positive wetland. We provide evidence that Bd occurs in the environment year-round. Bd exhibited temporal and spatial heterogeneity in density, but did not exhibit seasonality in occupancy. Bd was detected in all months, typically at less than 100 zoospores L⁻¹. The highest density observed was ∼3 million zoospores L⁻¹. We detected Bd in 47% of sites sampled, but estimated that Bd occupied 61% of sites, highlighting the importance of accounting for imperfect detection. When Bd was present, there was a 95% chance of detecting it with four samples of 600 ml of water or five samples of 60 mL. Our findings provide important baseline information to advance the study of Bd disease ecology, and advance our understanding of amphibian exposure to free-living Bd in aquatic habitats over time.     

Improvement in raw sago starch degrading enzyme production from Acremonium sp. endophytic fungus using carbon and nitrogen sources

Attempts were made to improve the growth of endophytic fungus Acremonium sp. and its raw sago starch degrading enzyme (RSSDE) production using different nitrogen and carbon sources at varying pH values and temperatures. It was observed that growth and enzyme activity levels were highest with peptone and sodium nitrate as the nitrogen sources and raw sago starch as the carbon source of which the optimum concentrations were 0.5 g/l, 3 g/l, and 20 g/l, respectively. Cell growth and RSSDE production reached their optimum at pH 5.0 and incubation temperature of 30 degrees C. Under these conditions, the enzyme production was significantly increased by 19- to 22-folds compared to the activity obtained in the original basal medium.     

Improvement of the contrast in cancer detection by autofluorescence bronchoscopy using a narrowband spectral violet excitation: A preliminary study

Autofluorescence (AF) bronchoscopy is a useful tool for early cancer detection. However, the mechanisms involved in this diagnosis procedure are poorly understood. We present a clinical autofluorescence imaging study to assess the depth of the principal contrast mechanisms within the bronchial tissue comparing a narrowband (superficial) and broadband (penetrating) violet excitation. Knowledge of this parameter is crucial for the optimization of the spectral and optical design of clinical diagnostic AF imaging devices. An intensity contrast improvement was observed with the narrowband excitation, suggesting that the heme absorption plays a key role in the AF contrast mechanism.