The Genome of a Bacillus Isolate Causing Anthrax in Chimpanzees Combines Chromosomal Properties of B. cereus with B. anthracis Virulence Plasmids

Anthrax is a fatal disease caused by strains of Bacillus anthracis. Members of this monophyletic species are non motile and are all characterized by the presence of four prophages and a nonsense mutation in the plcR regulator gene. Here we report the complete genome sequence of a Bacillus strain isolated from a chimpanzee that had died with clinical symptoms of anthrax. Unlike classic B. anthracis, this strain was motile and lacked the four prohages and the nonsense mutation. Four replicons were identified, a chromosome and three plasmids. Comparative genome analysis revealed that the chromosome resembles those of non-B. anthracis members of the Bacillus cereus group, whereas two plasmids were identical to the anthrax virulence plasmids pXO1 and pXO2. The function of the newly discovered third plasmid with a length of 14 kbp is unknown. A detailed comparison of genomic loci encoding key features confirmed a higher similarity to B. thuringiensis serovar konkukian strain 97-27 and B. cereus E33L than to B. anthracis strains. For the first time we describe the sequence of an anthrax causing bacterium possessing both anthrax plasmids that apparently does not belong to the monophyletic group of all so far known B. anthracis strains and that differs in important diagnostic features. The data suggest that this bacterium has evolved from a B. cereus strain independently from the classic B. anthracis strains and established a B. anthracis lifestyle. Therefore we suggest to designate this isolate as “B. cereus variety (var.) anthracis”.     

Drought in an evolutionary context: molecular variability in Flannelmouth Sucker (Catostomus latipinnis) from the Colorado River Basin of western North America

Summary 1. Fishes can often rebound numerically and distributionally from short‐term (i.e. seasonal) drought, yet their capacity to recover from decades or centuries of drought is less apparent. An exceedingly warm and dry period swept the intermontane west of North America ca. 7500 years BP, concomitant with an abrupt extinction of >35 mammal species. Were larger fishes in mainstem rivers also impacted by this drought? 2. The Colorado River Basin encompasses seven states in western North America and drains 600 000 km². Its endemic mainstem fish community is ancient (i.e. Miocene) but depauperate. 3. We evaluated one widely distributed candidate species (flannelmouth sucker, Catostomus latipinnis) for basin‐wide genetic and geographic structure at three fast‐evolving mitochondrial (mt) DNA genes, ND2 with 589 bp and ATPase 8 and 6 with 642 bp. It is hypothesized that a concomitant signature would be present in the mtDNA of this species, if indeed it had been seriously bottlenecked by post‐Pleistocene drought. A total of 352 individuals were sequenced from 24 populations (4–40 individuals/population; average of 14.7). 4. Only 49 unique haplotypes were found, 53% of which represented single individuals. Haplotype diversity was high (0.905 ± 0.007) whereas nucleotide diversity was low (0.002 ± 0.000). 5. A significant and positive geographical cline (P < 0.001) in nucleotide diversity was observed as sampling locations progressed upstream from southwest to northeast. These results divided the Colorado River Basin into three reaches: the lower reach with six populations and 83 individuals; the upper reach with seven populations and 83 individuals; and the middle reach with 11 populations and 186 individuals. An analysis of molecular variance (amova ) revealed that 81.5% of the total genetic variation was within populations, 16% among populations within reaches and 2.5% among reaches. Only the last was significant. Populations from the three reaches diverged from one another by 3400–11 000 years BP. Haplotype distribution suggested populations in the upper Colorado River are expanding. 6. The lack of genetic variation and recent coalescence of lineages in C. latipinnis are unusual given its fossil history, broad geographical sampling, the rapid rate of mtDNA evolution and the number (and evolutionary rate) of the genes examined. The most parsimonious explanation for these data is a rapid expansion following a recent period of low effective population size at the end of the Pleistocene. 7. The intense drought is suggested at the end of the Pleistocene (late‐to‐mid‐Holocene), severely impacted not only large mammals but also larger fishes in western North American rivers. These perspectives have important implications for management of endangered and threatened species in this region.     

Changes in the repertoire of natural antibodies caused by immunization with bacterial antigens

The repertoire of natural anti-glycan antibodies in naive chickens and in chickens immunized with bacteria Burkholderia mallei, Burkholderia pseudomallei, and Francisella tularensis as well as with peptides from an outer membrane protein of B. pseudomallei was studied. A relatively restricted pattern of natural antibodies (first of all IgY against bacterial cell wall peptidoglycan fragments, L-Rha, and core N-acetyllactosamine) shrank and, moreover, the level of detectable antibodies decreased as a result of immunization.     

Invasion of <Emphasis Type="Italic">Trypanosoma cruzi</Emphasis> into host cells is impaired by <Emphasis Type="Italic">N</Emphasis>-propionylmannosamine and other <Emphasis Type="Italic">N</Emphasis>-acylmannosamines

The etiologic agent of Chagas’ disease, Trypanosoma cruzi, is widely distributed in South America, affecting millions of people with thousands of deaths every year. Adherence of the infectious trypomastigote to host cells is mediated by sialic acid. T. cruzi cannot synthesize sialic acids on their own but cleave them from the host cells and link them to glycans on the surface of the parasites using the trans-sialidase, a GPI-anchored enzyme. The infectivity of the protozoan parasites strongly depends on the activity of this enzyme. In this report, we investigated whether the transfer of sialic acids from the host to the parasites can be attenuated using novel sialic acid precursors. The cell line 86-HG-39 was infected with T. cruzi and treated with defined N-acylmannosamine analogues bearing an elongated N-acyl side-chain. By treatment of these cells the number of T.cruzi infected cell was reduced up to 60%. We also showed that the activity of the bacterial sialidase C was reduced with N-glycan substrates with elongated N-acyl side chains of the terminal sialic acids. The affinity of this sialidase decreased with the length of the N-acyl side-chain. The data presented suggest that N-acyl modified sialic acid precursors can change the transfer of sialic acids leading to modification of infection. Since the chemotherapy of this disease is inefficient and afflicted by side effects, the need of effective drugs is lasting. These findings propose a new path to prevent the dissemination of T. cruzi in the human hosts. These compounds or further modified analogues might be a basis for the search of new agents against Chagas’ disease.     

Peripheral profiling analysis for bipolar disorder reveals markers associated with reduced cell survival

Little is known about the molecular factors that are altered in remitting bipolar disorder (BD) patients. We carried out proteome profiling of peripheral blood mononuclear cells (PBMCs) and serum from BD patients who were not experiencing mania or major depression (euthymia) compared to matched healthy controls using liquid chromatography–mass spectrometry (LC‐MS^E) and Multi‐Analyte Profiling (Human Map^®) platforms. This resulted in the identification of approximately 60 differentially expressed molecules involved predominantly in cell death/survival pathways. In PBMCs, this was manifested in cytoskeletal and stress response‐associated proteins, whereas most serum analytes were associated with the inflammatory response. The predicted effect of serum analytes on physiological systems was tested by treating PBMCs with serum obtained from the same patients, resulting in reduced cellular survival. These preliminary results suggest that BD patients carry a peripheral fingerprint that has detrimental effects on cell function and that could be used to distinguish BD patients from healthy controls despite being in a remission phase. It is hoped that additional studies of BD patients in the manic and depressed stages could lead to the identification of a molecular fingerprint that could be used for predicting episodic switching and for guiding treatment strategies.     

Automated discrimination of brain pathological state attending to complex structural brain network properties: the shiverer mutant mouse case

Neuroimaging classification procedures between normal and pathological subjects are sparse and highly dependent of an expert''s clinical criterion. Here, we aimed to investigate whether possible brain structural network differences in the shiverer mouse mutant, a relevant animal model of myelin related diseases, can reflect intrinsic individual brain properties that allow the automatic discrimination between the shiverer and normal subjects. Common structural networks properties between shiverer (C3Fe.SWV Mbp^shi/Mbp^shi, n = 6) and background control (C3HeB.FeJ, n = 6) mice are estimated and compared by means of three diffusion weighted MRI (DW-MRI) fiber tractography algorithms and a graph framework. Firstly, we found that brain networks of control group are significantly more clustered, modularized, efficient and optimized than those of the shiverer group, which presented significantly increased characteristic path length. These results are in line with previous structural/functional complex brain networks analysis that have revealed topologic differences and brain network randomization associated to specific states of human brain pathology. In addition, by means of network measures spatial representations and discrimination analysis, we show that it is possible to classify with high accuracy to which group each subject belongs, providing also a probability value of being a normal or shiverer subject as an individual anatomical classifier. The obtained correct predictions (e.g., around 91.6–100%) and clear spatial subdivisions between control and shiverer mice, suggest that there might exist specific network subspaces corresponding to specific brain disorders, supporting also the point of view that complex brain network analyses constitutes promising tools in the future creation of interpretable imaging biomarkers.     

Mutations in MITF and PAX3 cause "splashed white" and other white spotting phenotypes in horses

During fetal development neural-crest-derived melanoblasts migrate across the entire body surface and differentiate into melanocytes, the pigment-producing cells. Alterations in this precisely regulated process can lead to white spotting patterns. White spotting patterns in horses are a complex trait with a large phenotypic variance ranging from minimal white markings up to completely white horses. The "splashed white" pattern is primarily characterized by an extremely large blaze, often accompanied by extended white markings at the distal limbs and blue eyes. Some, but not all, splashed white horses are deaf. We analyzed a Quarter Horse family segregating for the splashed white coat color. Genome-wide linkage analysis in 31 horses gave a positive LOD score of 1.6 in a region on chromosome 6 containing the PAX3 gene. However, the linkage data were not in agreement with a monogenic inheritance of a single fully penetrant mutation. We sequenced the PAX3 gene and identified a missense mutation in some, but not all, splashed white Quarter Horses. Genome-wide association analysis indicated a potential second signal near MITF. We therefore sequenced the MITF gene and found a 10 bp insertion in the melanocyte-specific promoter. The MITF promoter variant was present in some splashed white Quarter Horses from the studied family, but also in splashed white horses from other horse breeds. Finally, we identified two additional non-synonymous mutations in the MITF gene in unrelated horses with white spotting phenotypes. Thus, several independent mutations in MITF and PAX3 together with known variants in the EDNRB and KIT genes explain a large proportion of horses with the more extreme white spotting phenotypes.     

Koi herpesvirus (KHV) and KHV disease (KHVD) – a recently updated overview

Over the last years, there has been an enormous increase in the knowledge on koi herpesvirus (KHV), koi herpesvirus disease (KHVD), pathogenesis and virus variants. Different KHV lineages have clearly been identified, possible genomic changes during replication in different cell cultures at different temperatures but also in several hosts have been identified, a persistent stage of infection has been specified and it has been shown that infection with KHV is not host specific at all, but KHVD is. Additionally, it has been shown that it is possible to combat KHVD by immunization with inactivated and attenuated live vaccines using different delivery systems but also to benefit from alternative treatments with e.g. exopolysaccharids obtained from Arthrospira platensis.     

Increased alpha-defensins as a blood marker for schizophrenia susceptibility

Schizophrenia is a severe psychotic illness affecting 1% of the general population. There are no consistent pathological features, and the disorder is defined by a complex symptomatology, which overlaps with other psychiatric illnesses. Diagnosis is based on a clinical interview, relying on the patient meeting criteria according to diagnosis manuals, including Diagnostic and Statistical Manual of Mental Disorders, 4th Ed. and International Statistical Classification of Diseases, 10th Revision. Because of the ambiguous symptoms, the diagnostic process can take many months and often years. Rapid and effective treatment has been shown to impact positively on disease progression and outcome, and it is therefore important to identify disease-associated biomarkers allowing early diagnosis. Reliable biomarkers can be used for the development of diagnostic tests and may also help us understand the underlying pathology of this disorder. In the present study, proteins from anti-CD3 stimulated and unstimulated peripheral blood T cell lysates from 15 minimally medicated and unmedicated patients and 15 age-, sex-, race-, and smoking-matched controls were profiled on cation exchange (CM10) chips using SELDI-TOF. Partial least squares discriminate analysis was used to separate patient and control groups according to the expression of 108 detected peaks, and two peaks of 3,374 and 3,450 Da, corresponding to alpha-defensins based on masses and cationic properties, were found to contribute significantly to the separation of patient and control groups. Reduction of T cell lysates with DTT resulted in a 6-Da shift in the mass of these peaks consistent with the presence of three cysteine bonds in the structure, confirming them as alpha-defensins. Quantification of alpha-defensins in T cell lysates from six patients and 18 healthy controls was carried out by ELISA, which also showed that alpha-defensin levels were significantly increased in patient lysates when compared with matched controls (p = 0.0197). Plasma from 21 monozygotic twins discordant for schizophrenia and eight healthy unaffected twin pairs was also analyzed for the expression of alpha-defensins by ELISA. Notably both affected and unaffected twins were found to have significantly elevated alpha-defensin levels compared with healthy control twin pairs (p = 0.0014 and p = 0.0115, respectively). Increased expression of alpha-defensins in unaffected as well as affected discordant monozygotic twins is of particular interest as monozygotic twins share genes and usually environmental upbringing. The unaffected twin therefore represents the biological and environmental risk of developing schizophrenia in the absence of overt symptomatology and therapeutic medication. These findings suggest that alpha-defensins could be an important early indicator of the risk of schizophrenia.     

Seroprevalence study of Francisella tularensis among hunters in Germany

In 2005 and 2006, Francisella tularensis unexpectedly reemerged in western Germany, when several semi-free-living marmosets (Callithrix jacchus) in a research facility died from tularemia and a group of hare hunters became infected. It is believed that hunters may have an elevated risk to be exposed to zoonotic pathogens, including F. tularensis. A previous cross-sectional study of the German population (n=6883) revealed a prevalence of 0.2%. Here, we investigated 286 sera from individuals mainly hunting in districts with emerging tularemia cases (group 1) and 84 sera from a region currently not conspicuous for tularemia (group 2). Methods included standard enzyme-linked immunosorbent assay (ELISA), Western blot analysis and indirect immunofluorescence assay. We found five out of the 286 hunters (1.7%; 95% CI 0.6-4.0%) in group 1 positive with standard ELISA and Western blot, but none in the Berlin area (group 2; 95% CI 0-0.04%). Group 1 showed an elevated risk for hunters to be seropositive for F. tularensis compared with the cross-sectional study (OR=7.7; P<0.001). This indicates a higher prevalence for tularemia in hunters of a suspected endemic region of Germany.