24 research outputs found
Data from: Evidence for selective sweeps by Wolbachia infections: phylogeny of Altica leaf beetles and their reproductive parasites
Infections with maternally inherited Wolbachia bacteria may have dramatic influences on reproductive traits and speciation patterns of their hosts. We here show that in the beetle genus Altica, infection has influenced phylogenetic patterns of the host’s mtDNA and different strains led to repeated selective sweeps. By comparing a COI/II based phylogeny of the hosts with a phylogeny of the bacteria based on ftsZ, we show that co-speciation is rare and restricted to few recently diverged species. While in general each species apparently harbours a single Wolbachia strain, A. lythri presents a strikingly different pattern: in the polyphyletic species three highly divergent mtDNA haplotypes (2.1 – 4.6% p-distance) are coupled with three different Wolbachia strains (wLytA1, wLytA2, wLytB). These haplotypes and Wolbachia strains are widely distributed and mostly found in sympatry. A phylogeny based on microsatellite data supports the monophyly of A. lythri. The discrepancy between mtDNA and nuclear phylogeny may best be explained by interspecific hybridization that led to introgression of mtDNA coupled with a different Wolbachia strain. Selective sweeps apparently drove the introgressed haplotypes to widespread distribution. As for effects of Wolbachia on reproduction, infection with wLytA1 appears to be correlated with a substantial sex ratio distortion, which was most prominent in A. lythri
Aligned Cytochrome Oxydase sequences from Altica (Coleoptera, Alticinae)
Aligned Cytochrome Oxydase sequences from Altica (Coleoptera, Alticinae
Aligned ftsZ sequences from Wolbachia infecting Altica and other Alticinae (Coleoptera)
Aligned ftsZ sequences from Wolbachia infecting Altica and other Alticinae (Coleoptera
Aligned sequences of Internal Tanscribed Spacer (ITS2) from Altica (Coleoptera, Alticinae)
Aligned sequences of Internal Tanscribed Spacer (ITS2) from Altica (Coleoptera, Alticinae
Characterization of trh2 harbouring Vibrio parahaemolyticus strains isolated in Germany.
Vibrio parahaemolyticus is a recognized human enteropathogen. Thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH) as well as the type III secretion system 2 (T3SS2) are considered as major virulence factors. As tdh positive strains are not detected in coastal waters of Germany, we focused on the characterization of trh positive strains, which were isolated from mussels, seawater and patients in Germany.Ten trh harbouring V. parahaemolyticus strains from Germany were compared to twenty-one trh positive strains from other countries. The complete trh sequences revealed clustering into three different types: trh1 and trh2 genes and a pseudogene Ψtrh. All German isolates possessed alleles of the trh2 gene. MLST analysis indicated a close relationship to Norwegian isolates suggesting that these strains belong to the autochthonous microflora of Northern Europe seawaters. Strains carrying the pseudogene Ψtrh were negative for T3SS2β effector vopC. Transcription of trh and vopC genes was analyzed under different growth conditions. Trh2 gene expression was not altered by bile while trh1 genes were inducible. VopC could be induced by urea in trh2 bearing strains. Most trh1 carrying strains were hemolytic against sheep erythrocytes while all trh2 positive strains did not show any hemolytic activity. TRH variants were synthesized in a prokaryotic cell-free system and their hemolytic activity was analyzed. TRH1 was active against sheep erythrocytes while TRH2 variants were not active at all.Our study reveals a high diversity among trh positive V. parahaemolyticus strains. The function of TRH2 hemolysins and the role of the pseudogene Ψtrh as pathogenicity factors are questionable. To assess the pathogenic potential of V. parahaemolyticus strains a differentiation of trh variants and the detection of T3SS2β components like vopC would improve the V. parahaemolyticus diagnostics and could lead to a refinement of the risk assessment in food analyses and clinical diagnostics
Two monoclonal antibodies against glycoprotein Gn protect mice from Rift Valley Fever challenge by cooperative effects.
Rift Valley fever virus (RVFV) is a zoonotic arbovirus that causes severe disease in humans and ruminants. The infection is characterized by abortions in pregnant animals, high mortality in neonates as well as febrile illness in humans that develop in 1% of cases encephalitis or hemorrhagic fever. There is presently no specific antiviral treatment for RVFV infection available. In this study, two monoclonal antibodies (mAbs), raised against glycoprotein Gn, were applied in a therapeutic study. Treatment of RVFV infected mice with neutralizing mAb Gn3 alone at two different time points (30 minutes before or 30 minutes after virus challenge) showed only moderate efficacy of about 58.3% survival in both applications. However, a combination therapy together with non-neutralizing mAb Gn32 demonstrated complete protection (100% survival) when applied 30 minutes after the lethal challenge dose. The increase of mAb efficacy is probably based on cooperative neutralization effects. These data suggest that a combination therapy with mAbs Gn3 and Gn32 could be an effective treatment option against RVFV infection
Germ-free housing conditions do not affect aortic root and aortic arch lesion size of late atherosclerotic low-density lipoprotein receptor-deficient mice.
The microbiota has been linked to the development of atherosclerosis, but the functional impact of these resident bacteria on the lesion size and cellular composition of atherosclerotic plaques in the aorta has never been experimentally addressed with the germ-free low-density lipoprotein receptor-deficient (Ldlr-/- ) mouse atherosclerosis model. Here, we report that 16 weeks of high-fat diet (HFD) feeding of hypercholesterolemic Ldlr-/- mice at germ-free (GF) housing conditions did not impact relative aortic root plaque size, macrophage content, and necrotic core area. Likewise, we did not find changes in the relative aortic arch lesion size. However, late atherosclerotic GF Ldlr-/- mice had altered inflammatory plasma protein markers and reduced smooth muscle cell content in their atherosclerotic root plaques relative to CONV-R Ldlr-/- mice. Neither absolute nor relative aortic root or aortic arch plaque size correlated with age. Our analyses on GF Ldlr-/- mice did not reveal a significant contribution of the microbiota in late aortic atherosclerosis
Results of genotyping of <i>trh</i> positive strains (see Table 1).
<p>* German strains are indicated by an asterisk.</p><p>**Control strain was the sequenced pandemic strain RIMD2210633 which carries two <i>tdh</i> genes and no <i>trh</i> gene.</p><p>Results of genotyping of <i>trh</i> positive strains (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118559#pone.0118559.t001" target="_blank">Table 1</a>).</p
Polymerase chain reaction (PCR) primers, targets and amplification sizes used for genotyping.
<p>Polymerase chain reaction (PCR) primers, targets and amplification sizes used for genotyping.</p