Arcobacter ellisii sp. nov., isolated from mussels

As part of a study carried out for detecting Arcobacter spp. in shellfish, three mussel isolates that were Gram-negative slightly curved rods, non-spore forming, showed a new 16S rDNA-RFLP pattern with a specific identification method for the species of this genus. Sequences of the 16S rRNA gene and those of the housekeeping genes rpoB, gyrB and hsp60 provided evidence that these mussel strains belonged to an unknown genetic lineage within the genus Arcobacter. The similarity between the 16S rRNA gene sequence of the representative strain (F79-6^T) and type strains of the other Arcobacter species ranged between 94.1% with A. halophilus and 99.1% with the recently proposed species A. defluvii (CECT 7697^T). DDH results between strain F79-6^T and the type strain of the latter species were below 70% (53 ± 3.0%). Phenotypic characteristics together with MALDITOF mass spectra differentiated the new mussel strains from all other Arcobacter species. All the results indicate that these strains represent a new species, for which the name Arcobacter ellisii sp. nov. with the type strain F79-6^T (=CECT 7837^T = LMG 26155^T) is proposed.     

T-helper 17 cell cytokines and interferon type I: partners in crime in systemic lupus erythematosus?

Introduction

A hallmark of systemic autoimmune diseases like systemic lupus erythematosus (SLE) is the increased expression of interferon (IFN) type I inducible genes, so-called IFN type I signature. Recently, T-helper 17 subset (Th17 cells), which produces IL-17A, IL-17F, IL-21, and IL-22, has been implicated in SLE. As CCR6 enriches for Th17 cells, we used this approach to investigate whether CCR6⁺ memory T-helper cells producing IL-17A, IL-17F, IL-21, and/or IL-22 are increased in SLE patients and whether this increase is related to the presence of IFN type I signature.

Methods

In total, 25 SLE patients and 15 healthy controls (HCs) were included. SLE patients were divided into IFN type I signature-positive (IFN⁺) (n = 16) and negative (IFN^-) (n = 9) patients, as assessed by mRNA expression of IFN-inducible genes (IFIGs) in monocytes. Expression of IL-17A, IL-17F, IL-21, and IL-22 by CD4⁺CD45RO⁺CCR6⁺ T cells (CCR6⁺ cells) was measured with flow cytometry and compared between IFN⁺, IFN^- patients and HCs.

Results

Increased percentages of IL-17A and IL-17A/IL-17F double-producing CCR6⁺ cells were observed in IFN⁺ patients compared with IFN^- patients and HCs. IL-17A and IL-17F expression within CCR6⁺ cells correlated significantly with IFIG expression. In addition, we found significant correlation between B-cell activating factor of the tumor necrosis family (BAFF)–a factor strongly correlating with IFN type I - and IL-21 producing CCR6⁺ cells.

Conclusions

We show for the first time higher percentages of IL-17A and IL-17A/IL-17F double-producing CCR6⁺ memory T-helper cells in IFN⁺ SLE patients, supporting the hypothesis that IFN type I co-acts with Th17 cytokines in SLE pathogenesis.     

The relationship between lateral meniscus shape and joint contact parameters in the knee: a study using data from the Osteoarthritis Initiative

Introduction

The meniscus has an important role in force transmission across the knee, but a detailed three-dimensional (3D) morphometric shape analysis of the lateral meniscus to elucidate subject-specific function has not been conducted. The aim of this study was to perform 3D morphometric analyses of the lateral meniscus in order to correlate shape variables with anthropometric parameters, thereby gaining a better understanding of the relationship between lateral meniscus shape and its load-bearing function.

Methods

The lateral meniscus (LM) was manually segmented from magnetic resonance images randomly selected from the Osteoarthritis Initiative (OAI) non-exposed control subcohort. A 3D statistical shape model (SSM) was constructed to extract the principal morphological variations (PMV) of the lateral meniscus for 50 subjects (25 male and 25 female). Correlations between the principal morphological variations and anthropometric parameters were tested. Anthropometric parameters that were selected included height, weight, body mass index (BMI), femoral condyle width and axial rotation.

Results

The first principal morphological variation (PMV) was found to correlate with height (r = 0.569), weight (r = 0.647), BMI (r = 0.376), and femoral condyle width (r = 0.622). The third PMV was found to correlate with height (r = 0.406), weight (r = 0.312), and femoral condyle width (r = 0.331). The percentage of the tibial plateau covered by the lateral meniscus decreases as anthropometric parameters relating to size of the subject increase. Furthermore, when the size of the subject increases, the posterior and anterior horns become proportionally longer and wider.

Conclusion

The correlations discovered suggest that variations in meniscal shape can be at least partially explained by the levels of loads transmitted across the knee on a regular basis. Additionally, as the size of the subject increases and body weight rises, the coverage percentage of the meniscus is reduced, suggesting that there would be an increase in the load-bearing by the cartilage. However, this reduced coverage percentage is compensated by the proportionally wider and longer meniscal horn.     

Courtship Behavior of Zaprionus indianus (Gupta) (Diptera: Drosophilidae) from Populations Colonizing South America

We describe for the first time the sexual behavior and the courtship song of males of the African fly Zaprionus indianus (Gupta), a recent invader of South America. The male courtship song is formed by monocyclic pulses and the courtship behavior is simple when compared to that of species of Drosophila. Two interpulse interval (IPI) distributions were observed: pre-mounting and mounting. No significant difference was observed between the pre-mounting IPIs of males that descended from three geographical populations from South America. We also observed the songs produced by females and the homosexual behavior exhibited by males. A sequence of bursts is produced by females as a refusal signal against males, while males emit a characteristic song that identifies sex genus, which differs from the courtship song. The short courtship and mating latencies recorded reveal vigorous males and receptive females, respectively.     

Microarray-Based Identification of Differentially Expressed Genes in Families of Turbot (Scophthalmus maximus) After Infection with Viral Haemorrhagic Septicaemia Virus (VHSV)

Viral haemorrhagic septicaemia virus (VHSV) is one of the major threats to the development of the aquaculture industry worldwide. The present study was aimed to identify genes differentially expressed in several turbot (Scophthalmus maximus) families showing different mortality rates after VHSV. The expression analysis was conducted through genome-wide expression profiling with an oligo-microarray in the head kidney. A significant proportion of the variation in the gene expression profiles seemed to be explained by the genetic background, indicating that the mechanisms by which particular species and/or populations can resist a pathogen(s) are complex and multifactorial. Before the experimental infections, fish from resistant families (low mortality rates after VHSV infection) showed high expression of different antimicrobial peptides, suggesting that their pre-immune state may be stronger than fish of susceptible families (high mortality rates after VHSV infection). After infection, fish from both high- and low-mortality families showed an up-modulation of the interferon-induced Mx2 gene, the IL-8 gene and the VHSV-induced protein 5 gene compared with control groups. Low levels of several molecules secreted in the mucus were observed in high-mortality families, but different genes involved in viral entrance into target cells were down-regulated in low-mortality families. Moreover, these families also showed a strong down-modulation of marker genes related to VHSV target organs, including biochemical markers of renal dysfunction and myocardial injury. In general, the expression of different genes involved in the metabolism of sugars, lipids and proteins were decreased in both low- and high-mortality families after infection. The present study serves as an initial screen for genes of interest and provides an extensive overview of the genetic basis underlying the differences between families that are resistant or susceptible to VHSV infection.     

Toxoplasma gondii Sis1-like J-domain protein is a cytosolic chaperone associated to HSP90/HSP70 complex

Toxoplasma gondii is an obligate intracellular protozoan parasite in which 36 predicted Hsp40 family members were identified by searching the T. gondii genome. The predicted protein sequence from the gene ID TGME49_065310 showed an amino acid sequence and domain structure similar to Saccharomyces cerevisiae Sis1. TgSis1 did not show differences in its expression profile during alkaline stress by microarray analysis. Furthermore, TgSis1 showed to be a cytosolic Hsp40 which co-immunoprecipitated with T. gondii Hsp70 and Hsp90. Structural modeling of the TgSis1 peptide binding fragment revealed structural and electrostatic properties different from the experimental model of human Sis1-like protein (Hdj1). Based on these differences; we propose that TgSis1 may be a potentially attractive drug target for developing a novel anti-T. gondii therapy.     

Neonatal neurobehavior and diffusion MRI changes in brain reorganization due to intrauterine growth restriction in a rabbit model

Background

Intrauterine growth restriction (IUGR) affects 5–10% of all newborns and is associated with a high risk of abnormal neurodevelopment. The timing and patterns of brain reorganization underlying IUGR are poorly documented. We developed a rabbit model of IUGR allowing neonatal neurobehavioral assessment and high resolution brain diffusion magnetic resonance imaging (MRI). The aim of the study was to describe the pattern and functional correlates of fetal brain reorganization induced by IUGR.

Methodology/Principal Findings

IUGR was induced in 10 New Zealand fetal rabbits by ligation of 40–50% of uteroplacental vessels in one horn at 25 days of gestation. Ten contralateral horn fetuses were used as controls. Cesarean section was performed at 30 days (term 31 days). At postnatal day +1, neonates were assessed by validated neurobehavioral tests including evaluation of tone, spontaneous locomotion, reflex motor activity, motor responses to olfactory stimuli, and coordination of suck and swallow. Subsequently, brains were collected and fixed and MRI was performed using a high resolution acquisition scheme. Global and regional (manual delineation and voxel based analysis) diffusion tensor imaging parameters were analyzed. IUGR was associated with significantly poorer neurobehavioral performance in most domains. Voxel based analysis revealed fractional anisotropy (FA) differences in multiple brain regions of gray and white matter, including frontal, insular, occipital and temporal cortex, hippocampus, putamen, thalamus, claustrum, medial septal nucleus, anterior commissure, internal capsule, fimbria of hippocampus, medial lemniscus and olfactory tract. Regional FA changes were correlated with poorer outcome in neurobehavioral tests.

Conclusions

IUGR is associated with a complex pattern of brain reorganization already at birth, which may open opportunities for early intervention. Diffusion MRI can offer suitable imaging biomarkers to characterize and monitor brain reorganization due to fetal diseases.     

Recombinant infectious hematopoietic necrosis viruses induce protection for rainbow trout Oncorhynchus mykiss

Infectious hematopoietic necrosis virus (IHNV) and viral hemorrhagic septicaemia virus (VHSV) are rhabdoviruses that infect salmonids, producing serious economic losses. Two recombinant IHN viruses were generated by reverse genetics. For one (rIHNV GFP) the IHNV NV gene was replaced with the green fluorescent protein (GFP) gene. In the other (rIHNV-Gvhsv GFP) the G gene was also exchanged for that of VHSV. No mortalities, external signs or histological lesions were observed in experimental infections conducted with the recombinant viruses. Neither the rIHNV GFP nor rIHNV-Gvhsv GFP was detected by RT-PCR in any of the examined tissues from experimentally infected fish. In order to assess their potential as vaccines against the wild type viruses, rainbow trout were vaccinated with the recombinant viruses by intraperitoneal injection and challenged 30 d later with virulent IHNV or VHSV. The GFP viruses provided protection against both wild type viruses. None of the recombinant viruses induced antibody production, and the expression of interferon (IFNalpha4) and interferon induced genes such as Mx protein and ISG-15 was not different to that of controls. The rIHNV-Gvhsv GFP did not inhibit cellular apoptosis as it was observed in an IHNV inoculated fish cell line. These studies suggest that the recombinant rIHNV-Gvhsv GFP is a promising candidate as a live recombinant vaccine and also provides a good model to further study viral pathogenicity and the molecular basis of protection against these viral infections.