Estrella lausannensis, a new star in the Chlamydiales order

Originally, the Chlamydiales order was represented by a single family, the Chlamydiaceae, composed of several pathogens, such as Chlamydia trachomatis, Chlamydia pneumoniae, Chlamydia psittaci and Chlamydia abortus. Recently, 6 new families of Chlamydia-related bacteria have been added to the Chlamydiales order. Most of these obligate intracellular bacteria are able to replicate in free-living amoebae. Amoebal co-culture may be used to selectively isolate amoeba-resisting bacteria. This method allowed in a previous work to discover strain CRIB 30, from an environmental water sample. Based on its 16S rRNA gene sequence similarity with Criblamydia sequanensis, strain CRIB 30 was considered as a new member of the Criblamydiaceae family. In the present work, phylogenetic analyses of the genes gyrA, gyrB, rpoA, rpoB, secY, topA and 23S rRNA as well as MALDI-TOF MS confirmed the taxonomic classification of strain CRIB 30. Morphological examination revealed peculiar star-shaped elementary bodies (EBs) similar to those of C. sequanensis. Therefore, this new strain was called "Estrella lausannensis". Finally, E. lausannensis showed a large amoebal host range and a very efficient replication rate in Acanthamoeba species. Furthermore, E. lausannensis is the first member of the Chlamydiales order to grow successfully in the genetically tractable Dictyostelium discoideum, which opens new perspectives in the study of chlamydial biology.     

The IRG protein-based resistance mechanism in mice and its relation to virulence in Toxoplasma gondii

IRG proteins (immunity-related GTPases) provide an early defense mechanism in mice against the protozoal pathogen, Toxoplasma gondii. This is a particularly suitable time to provide a brief review of this host-pathogen interaction because the nature of the IRG resistance system, and to some extent its mode of action, have become known in the past few years. Likewise, forward genetic screens have recently drawn attention to a number of loci contributing to the differential virulence of T. gondii strains in mice. It is now clear that at least some important virulence mechanisms exert their action against components of the IRG resistance system. Thus these two mechanisms form the two poles of a dynamic host-pathogen virulence-resistance relationship with interesting and accessible properties.     

mRNA expression levels of the biological factors uPAR, uPAR-del4/5, and rab31, displaying prognostic value in breast cancer, are not clinically relevant in advanced ovarian cancer

High tumor tissue mRNA expression of the tumor biological factors uPAR, uPAR-del4/5, or rab31 is associated with shorter distant metastasis-free and overall survival in breast cancer patients. To evaluate whether these factors are also clinically relevant in ovarian cancer, we quantified the respective mRNA levels in primary tumor tissue of advanced ovarian cancer patients (n=103) and evaluated their association with clinicopathological parameters and patients' prognosis. mRNA expression levels of all three markers did not show any significant association with overall or progression-free survival, demonstrating that these factors have no prognostic value in advanced ovarian cancer.     

Abundance of introduced species at home predicts abundance away in herbaceous communities

Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at 39 sites, within eight countries, revealed that species abundances were similar at native (home) and introduced (away) sites - grass species were generally abundant home and away, while forbs were low in abundance, but more abundant at home. Sites with six or more of these species had similar community abundance hierarchies, suggesting that suites of introduced species are assembling similarly on different continents. Overall, we found that substantial changes to populations are not necessarily a pre-condition for invasion success and that increases in species abundance are unusual. Instead, abundance at home predicts abundance away, a potentially useful additional criterion for biosecurity programmes.     

High blood pressure,antihypertensive medication and lung function in a general adult population

Background

Several studies showed that blood pressure and lung function are associated. Additionally, a potential effect of antihypertensive medication, especially beta-blockers, on lung function has been discussed. However, side effects of beta-blockers have been investigated mainly in patients with already reduced lung function. Thus, aim of this analysis is to determine whether hypertension and antihypertensive medication have an adverse effect on lung function in a general adult population.

Methods

Within the population-based KORA F4 study 1319 adults aged 40-65 years performed lung function tests and blood pressure measurements. Additionally, information on anthropometric measurements, medical history and use of antihypertensive medication was available. Multivariable regression models were applied to study the association between blood pressure, antihypertensive medication and lung function.

Results

High blood pressure as well as antihypertensive medication were associated with lower forced expiratory volume in one second (p = 0.02 respectively p = 0.05; R²: 0.65) and forced vital capacity values (p = 0.01 respectively p = 0.05, R²: 0.73). Furthermore, a detailed analysis of antihypertensive medication pointed out that only the use of beta-blockers was associated with reduced lung function, whereas other antihypertensive medication had no effect on lung function. The adverse effect of beta-blockers was significant for forced vital capacity (p = 0.04; R²: 0.65), while the association with forced expiratory volume in one second showed a trend toward significance (p = 0.07; R²: 0.73). In the same model high blood pressure was associated with reduced forced vital capacity (p = 0.01) and forced expiratory volume in one second (p = 0.03) values, too.

Conclusion

Our analysis indicates that both high blood pressure and the use of beta-blockers, but not the use of other antihypertensive medication, are associated with reduced lung function in a general adult population.     

A global population redistribution in a migrant shorebird detected with continent‐wide qualitative breeding survey data

Aim Over the last two decades, thousands of northward migrating ruffs (Philomachus pugnax) have disappeared from western European staging sites. These migratory ruffs were partly temperate breeding birds, but most individuals head towards the Eurasian Arctic tundras where 95% of the global population breeds. This regional decline may represent either: (1) local loss of breeding birds in western Europe, (2) a global decline, (3) shift(s) in distribution or (4) a combination of these. Location Northern Eurasia. Methods To put the declines in western Europe in context, we analysed Arctic monitoring data from the last two decades ( Soloviev & Tomkovich, 2009 ) to detect changes in regional breeding densities across northern Eurasia. We used a novel approach applying generalized additive modelling (GAM) and generalized estimations equations (GEE). Results We show that the global breeding population of ruffs has made a significant eastwards shift into the Asian part of the breeding range. In the European Arctic, ruffs decreased during the last 18 years. At the same time, in western Siberia, ruffs increased. In eastern Siberia, no significant population changes could be detected. These changes corroborate the finding that during northward migration, growing numbers of ruffs avoided staging areas in the Netherlands and Sweden and started migrating along a more easterly route leading into western Siberia. Main conclusions We detected an unprecedented large‐scale population redistribution of ruffs and suggest that this is a response to loss of habitat quality at the traditional staging site in the Netherlands.     

Genetic diversity of Dinaric brown bears (Ursus arctos) in Croatia with implications for bear conservation in Europe

Brown bears have lost most of their range on the European continent. The remaining western populations are small, isolated and highly endangered. The Dinaric-Pindos brown bear population is the western-most stable population and the fourth largest in Europe. It has been recognized as a potential source for recolonization of populations whose survival is at risk. Indeed, several translocations of Dinaric bears to Italy, Austria and France have recently been made. Despite the importance of the Dinaric bear population, its genetic status remains poorly understood. Using tissue samples from 156 hunted or accidentally killed Dinaric bears in Croatia, this study analysed genetic diversity at 12 microsatellite loci, as well as population structure and past reductions in size. In addition, a subset of 59 samples was used to assess diversity of the mitochondrial DNA control region. The results indicate that Dinaric bears have high nuclear genetic diversity, as compared to other extant brown bear populations, despite genetic evidence of a bottleneck caused by past persecutions. However, haplotype diversity was low, probably as a result of male-biased dispersal and female philopatry. Not surprisingly, no evidence of population sub-structure was found using nuclear markers, as the bear habitat has remained continuous and the highway network has been built only recently. Management should focus on maintaining habitat connectivity and keeping the effective population size as large as possible. In addition, when removing individuals, care should be taken not to further deplete the population of rare haplotypes. A coordinated transboundary management of the entire Dinaric-Pindos brown bear population should be a priority for its long-term conservation.