Biotrophic pathogens, such as the related maize pathogenic fungi Ustilago maydis and Sporisorium reilianum, establish an intimate relationship with their hosts by secreting protein effectors. Because ...secreted effectors interacting with plant proteins should rapidly evolve, we identified variable genomic regions by sequencing the genome of S. reilianum and comparing it with the U. maydis genome. We detected 43 regions of low sequence conservation in otherwise well-conserved syntenic genomes. These regions primarily encode secreted effectors and include previously identified virulence clusters. By deletion analysis in U. maydis, we demonstrate a role in virulence for four previously unknown diversity regions. This highlights the power of comparative genomics of closely related species for identification of virulence determinants.
The easyPACId (easy Promoter Activation and Compound Identification) approach is focused on the targeted activation of natural product biosynthetic gene clusters (BGCs) encoding non-ribosomal peptide ...synthetases (NRPS), polyketide synthases (PKS), NRPS-PKS hybrids, or other BGC classes. It was applied to entomopathogenic bacteria of the genera Xenorhabdus and Photorhabdus by exchanging the natural promoter of desired BGCs against the L-arabinose inducible PBAD promoter in ∆hfq mutants of the respective strains. The crude (culture) extracts of the cultivated easyPACId mutants are enriched with the single compound or compound class and can be tested directly against various target organisms without further purification of the produced natural products. Furthermore, isolation and identification of compounds from these mutants is simplified due to the reduced background in the ∆hfq strains. The approach avoids problems often encountered in heterologous expression hosts, chemical synthesis, or tedious extraction of desired compounds from wild-type crude extracts. This protocol describes easyPACId for Xenorhabdus and Photorhabdus, but it was also successfully adapted to Pseudomonas entomophila and might be suitable for other proteobacteria that carry hfq.
There are many causes of pericardial effusion and it is useful to classify them etiologically, since this disorder is the most common pathologic process involving the pericardium. This report details ...our experience with pericardioscopy and epicardial biopsy in 101 patients with pericardial effusions in whom pericardioscopy was performed. By means of clinical data and polymerase chain reaction we tried to elucidate the etiology of the pericardial effusion which were classified as follows: we found 41 effusions to be induced by primary malignant tumors or tumors metastatic to the pericardium. Specific diagnosis of viral and bacterial pericarditis was established in 17 patients by examination of the pericardial effusion with PCR, where we found 3 patients positive for adenovirus, 5 patients positive for cytomegalovirus, 2 patients positive for enterovirus-RNA and 5 patients positive for borrelia Burgdorferi-DNA. Additionally, idiopathic effusions (lymphocytic and autoreactive) were seen in 35 patients. In summary immunological and molecular biology investigations seem to provide an additional tool in the diagnostic of pericardial effusion with unknown etiology. If we focus on the ELISA results, there is some evidence, that the demonstration table: see text of activation markers and soluble mediators of inflammation such as Il-6, Il-8 and IFN-gamma in pericardial effusion and the simultaneously lack of these mediators in sera of the patients first may be helpful in the discrimination of autoreactive and lymphocytic effusion. Second, this cytokine pattern or distribution indicates a possible local inflammatory process, where these cytokines were all released from activated T lymphocytes present in lymphocytic effusion. In the future, this may have therapeutic implications.
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