Increasing role of arthropod bites in tularaemia transmission in Poland – case reports and diagnostic methods

The study describes four cases of tularaemia – one developed after contact with rabbits and three developed after an arthropod bite. Due to non-specific clinical symptoms, accurate diagnosis of tularaemia may be difficult. The increasing contribution of the arthropod vectors in the transmission of the disease indicates that special effort should be made to apply sensitive and specific diagnostic methods for tularaemia, and to remind health-care workers about this route of Francisella tularensis infections. The advantages and disadvantages of various diagnostic methods – molecular, serological and microbiological culture – are discussed. The PCR as a rapid and proper diagnostic method for ulceroglandular tularaemia is presented

Non-canonical HIF-1 stabilization contributes to intestinal tumorigenesis

The hypoxia-inducible transcription factor HIF-1 is appreciated as a promising target for cancer therapy. However, conditional deletion of HIF-1 and HIF-1 target genes in cells of the tumor microenvironment can result in accelerated tumor growth, calling for a detailed characterization of the cellular context to fully comprehend HIF-1's role in tumorigenesis. We dissected cell type-specific functions of HIF-1 for intestinal tumorigenesis by lineage-restricted deletion of the Hif1a locus. Intestinal epithelial cell-specific Hif1a loss reduced activation of Wnt/β-catenin, tumor-specific metabolism and inflammation, significantly inhibiting tumor growth. Deletion of Hif1a in myeloid cells reduced the expression of fibroblast-activating factors in tumor-associated macrophages resulting in decreased abundance of tumor-associated fibroblasts (TAF) and robustly reduced tumor formation. Interestingly, hypoxia was detectable only sparsely and without spatial association with HIF-1α, arguing for an importance of hypoxia-independent, i.e., non-canonical, HIF-1 stabilization for intestinal tumorigenesis that has not been previously appreciated. This adds a further layer of complexity to the regulation of HIF-1 and suggests that hypoxia and HIF-1α stabilization can be uncoupled in cancer. Collectively, our data show that HIF-1 is a pivotal pro-tumorigenic factor for intestinal tumor formation, controlling key oncogenic programs in both the epithelial tumor compartment and the tumor microenvironment

Some Bacillus thuringiensis strains share rpoB nucleotide polymorphisms also present in Bacillus anthracis

Identification of Bacillus anthracis is considerably difficult because of its very high phenotypic and genotypic similarity to other members of the Bacillus cereus group. Differentiation methods based on morphological and phenotypic characteristics are time-consuming, and false results may be obtained for atypical strains. On the other hand molecular discrimination based on the presence of two B. anthracis virulence plasmids, pXO1 and pXO2, is not sufficient because plasmids can be lost or transferred to other bacilli. Therefore, several chromosomal markers have been investigated and applied (1, 8). In 2001 Qi et al. (7) described single nucleotide polymorphisms (SNPs) in the rpoB gene and their usefulness for B. anthracis identification. Since then, several articles describing various molecular methods for rpoB sequence-based detection of B. anthracis have been published (for example see references 2 and 9). We conducted studies of single-strand conformation polymorphisms (SSCPs) of the rpoB gene in a large collection of B. cereus group strains. Surprisingly, we found that the nucleotide sequence of the rpoB gene fragment containing the marker SNPs of two reference strains of Bacillus thuringiensis was identical to that of the homologous region in B. anthracis. Therefore, rpoB gene-based tools could not distinguish these strains from B. anthracis, thus resulting in false-positive anthrax identification

Screening for anthrax occurrence in soil of flooded rural areas in Poland after rainfalls in spring 2010

[b]Introduction and objective[/b]. Anthrax spores remain viable and infectious in soil for decades. Flood water can percolate towards the surface the spores buried in soil. Moreover, the flood water might transport spores to areas previously unaffected. After the water recedes the spores located on the surface of the ground can be consumed by grazing animals and cause outbreaks of anthrax. [b]Materials and method[/b]. Soil samples were collected in areas of Poland most affected by floods in 2010 (Lubelskie, Świętokrzyskie, Podkarpackie and Mazowieckie provinces). After heating with the aim to kill vegetative forms of bacteria, the samples were cultured on PLET agar and the resulted colonies were investigated in terms of motility and presence of anthrax specific chromosomal (SG-749, plcR) and plasmid markers (capB, pagA). [b]Results.[/b] In total, 424 spore-forming, aerobically growing isolates were collected from the tested soil samples. Eighty-nine of them were non-motile. All the isolates were negative in PCR for anthrax specific chromosomal and plasmid markers. Conclusions. Spores of [i]B. anthracis[/i] that could be related to risk of anthrax outbreaks were not detected in soil samples tested in this study. The negative results presented may not be proof that Poland is country free of anthrax. The results, however, may suggest a relatively low risk of anthrax outbreaks being triggered in the sampled area

Increasing role of arthropod bites in tularaemia transmission in Poland - case reports and diagnostic methods

The study describes four cases of tularaemia – one developed after contact with rabbits and three developed after an arthropod bite. Due to non-specific clinical symptoms, accurate diagnosis of tularaemia may be difficult. The increasing contribution of the arthropod vectors in the transmission of the disease indicates that special effort should be made to apply sensitive and specific diagnostic methods for tularaemia, and to remind health-care workers about this route of Francisella tularensis infections. The advantages and disadvantages of various diagnostic methods – molecular, serological and microbiological culture – are discussed. The PCR as a rapid and proper diagnostic method for ulceroglandular tularaemia is presented

Specific Bacillus anthracis identification by a plcR-targeted restriction site insertion-PCR (RSI-PCR) assay

A RSI-PCR assay was developed for the detection of a Bacillus anthracis-specific nonsense mutation in the plcR gene. The assay specificity was tested using 170 Bacillus spp. strains including 47 strains of B. anthracis. The plcR RSI-PCR distinguished Bacillus cereus group strains closely related to B. anthracis from the anthrax agent. The assay was found to be a robust, simple and cost effective tool for B. anthracis identification. In contrast to previously developed real time PCR-based methods, the RSI-PCR needs basic molecular biology equipment only, and thus may be easily introduced in developing countries, where anthrax is endemic

Non-canonical HIF-1 stabilization is essential for intestinal tumorigenesis

The hypoxia-inducible transcription factor HIF-1 is appreciated as a promising target for cancer therapy. However, conditional deletion of HIF-1 and HIF-1 target genes in cells of the tumor microenvironment can result in accelerated tumor growth, calling for a detailed characterization of the cellular context to fully comprehend HIF-1's role in tumorigenesis. We dissected cell type-specific functions of HIF-1 for intestinal tumorigenesis by lineage-restricted deletion of the Hif1a locus. Intestinal epithelial cell-specific Hif1a loss reduced activation of wnt/b-catenin, tumor-specific metabolism and inflammation, significantly inhibiting tumor growth. Deletion of Hif1a in myeloid cells reduced the expression of fibroblast-activating factors in tumor-associated macrophages resulting in decreased abundance of tumor-associated fibroblasts and robustly reduced tumor formation. Interestingly, hypoxia was detectable only sparsely and without spatial association with nuclear HIF-1a in intestinal adenomas, pointing towards a functional importance of hypoxia-independent, i.e. non-canonical HIF-1 stabilization that has not been previously appreciated. This adds a further layer of complexity to the regulation of HIF-1a and suggests that hypoxia and HIF-1a stabilization can be uncoupled in cancer. Collectively, our data show that HIF-1 is a pivotal pro-tumorigenic factor for intestinal tumor formation, controlling key oncogenic programs in both the epithelial tumor compartment and the tumor microenvironment