A new web-based genomics resource for bioinformatics analysis of Rhipicephalus (Boophilus) microplus: CattleTickBase

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Microarray evidence for off target effects in tick RNA interference experiments, and the lack of strong correlation between DSRNA and antibody phenotypes in tick In vitro treatments for vaccine candidate screening

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Exploring the transcriptomic data of the Australian paralysis tick, Ixodes holocyclus

Ixodes holocyclus is the paralysis tick commonly found in Australia. I. holocyclus does not cause paralysis in the primary host – bandicoots, but markedly affects secondary hosts such as companion animals, livestock and humans. Holocyclotoxins are the neurotoxin molecules in I. holocyclus responsible for paralysis symptoms. There is a limited understanding of holocyclotoxins due to the difficulties in purifying and expressing these toxins in vitro. Next-generation sequencing technologies were utilised for the first time to generate transcriptome data from two cDNA samples –salivary glands samples collected from female adult ticks engorged on paralysed companion animals and on bandicoots. Contigencoded proteins in each library were annotated according to their best BLAST match against several databases and functionally assigned into six protein categories: housekeeping, transposable elements, pathogen-related, hypothetical, secreted and novel. The “secreted protein” category is comprised of ten protein families: enzymes, protease inhibitors, antigens, mucins, immunity-related, lipocalins, glycinerich, putative secreted, salivary and toxin-like. Comparisons of contig representation between the two libraries reveal the differential expression of tick proteins collected from different hosts. This study provides a preliminary description of the I. holocyclus tick salivary gland transcriptome

Exploring the transcriptomic data of the Australian paralysis tick, Ixodes holocyclus

Ixodes holocyclus is the paralysis tick commonly found in Australia. I. holocyclus does not cause paralysis in the primary host – bandicoots, but markedly affects secondary hosts such as companion animals, livestock and humans. Holocyclotoxins are the neurotoxin molecules in I. holocyclus responsible for paralysis symptoms. There is a limited understanding of holocyclotoxins due to the difficulties in purifying and expressing these toxins in vitro. Next-generation sequencing technologies were utilised for the first time to generate transcriptome data from two cDNA samples –salivary glands samples collected from female adult ticks engorged on paralysed companion animals and on bandicoots. Contigencoded proteins in each library were annotated according to their best BLAST match against several databases and functionally assigned into six protein categories: housekeeping, transposable elements, pathogen-related, hypothetical, secreted and novel. The “secreted protein” category is comprised of ten protein families: enzymes, protease inhibitors, antigens, mucins, immunity-related, lipocalins, glycinerich, putative secreted, salivary and toxin-like. Comparisons of contig representation between the two libraries reveal the differential expression of tick proteins collected from different hosts. This study provides a preliminary description of the I. holocyclus tick salivary gland transcriptome

Exploring the Transcriptomic Data of the Australian Paralysis Tick, Ixodes Holocyclus

Ixodes holocyclus is the paralysis tickcommonly found in Australia. I. holocyclus does notcause paralysis in the primary host – bandicoots, butmarkedly affects secondary hosts such as companionanimals, livestock and humans. Holocyclotoxins are theneurotoxin molecules in I. holocyclus responsible forparalysis symptoms. There is a limited understanding ofholocyclotoxins due to the difficulties in purifying andexpressing these toxins in vitro. Next-generationsequencing technologies were utilised for the first time togenerate transcriptome data from two cDNA samples –salivary glands samples collected from female adult ticksengorged on paralysed companion animals and onbandicoots. Contig-encoded proteins in each librarywere annotated according to their best BLAST matchagainst several databases and functionally assigned intosix protein categories: housekeeping, transposableelements, pathogen-related, hypothetical, secreted andnovel. The “secreted protein” category is comprised often protein families: enzymes, protease inhibitors,antigens, mucins, immunity-related, lipocalins, glycinerich,putative secreted, salivary and toxin-like.Comparisons of contig representation between the twolibraries reveal the differential expression of tickproteins collected from different hosts. This studyprovides a preliminary description of the I. holocyclustick salivary gland transcriptome

Evaluation of a Phenotypic MicroArray (BIOLOG) for characterisation of bovine reproductive Campylobacter fetus subspecies and other Campylobacter-like isolates by comparison with standard phenotypic, PCR and 16S rDNA sequencing

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Tick holocyclotoxins trigger host paralysis by presynaptic inhibition

Ticks are important vectors of pathogens and secreted neurotoxins with approximately 69 out of 692 tick species having the ability to induce severe toxicoses in their hosts. The Australian paralysis tick (Ixodes holocyclus) is known to be one of the most virulent tick species producing a flaccid paralysis and fatalities caused by a family of neurotoxins known as holocyclotoxins (HTs). The paralysis mechanism of these toxins is temperature dependent and is thought to involve inhibition of acetylcholine levels at the neuromuscular junction. However, the target and mechanism of this inhibition remain uncharacterised. Here, we report that three members of the holocyclotoxin family; HT-1 (GenBank AY766147), HT-3 (GenBank KP096303) and HT-12 (GenBank KP963967) induce muscle paralysis by inhibiting the dependence of transmitter release on extracellular calcium. Previous study was conducted using extracts from tick salivary glands, while the present study is the first to use pure toxins from I. holocyclus. Our findings provide greater insight into the mechanisms by which these toxins act to induce paralysis

Evaluation and histological examination of a Campylobacter fetus subsp. venerealis small animal infection model

Bovine genital campylobacteriosis (BGC), caused by Campylobacter fetus subsp. venerealis, is associated with production losses in cattle worldwide. This study aimed to develop a reliable BGC guinea pig model to facilitate future studies of pathogenicity, abortion mechanisms and vaccine efficacy. Seven groups of five pregnant guinea pigs (1 control per group) were inoculated with one of three strains via intra-peritoneal (IP) or intra-vaginal routes. Samples were examined using culture, PCR and histology. Abortions ranged from 0% to 100% and re-isolation of causative bacteria from sampled sites varied with strain, dose of bacteria and time to abortion. Histology indicated metritis and placentitis, suggesting that the bacteria induce inflammation, placental detachment and subsequent abortion. Variation of virulence between strains was observed and determined by culture and abortion rates. IP administration of C. fetus subsp. venerealis to pregnant guinea pigs is a promising small animal model for the investigation of BGC abortion

Evaluation and histological examination of a Campylobacter fetus subsp. venerealis small animal infection model

Bovine genital campylobacteriosis (BGC), caused by Campylobacter fetus subsp. venerealis, is associated with production losses in cattle worldwide. This study aimed to develop a reliable BGC guinea pig model to facilitate future studies of pathogenicity, abortion mechanisms and vaccine efficacy. Seven groups of five pregnant guinea pigs (1 control per group) were inoculated with one of three strains via intraperitoneal (IP) or intra-vaginal routes. Samples were examined using culture, PCR and histology. Abortions ranged from 0% to 100% and re-isolation of causative bacteria from sampled sites varied with strain, dose of bacteria and time to abortion. Histology indicated metritis and placentitis, suggesting that the bacteria induce inflammation, placental detachment and subsequent abortion. Variation of virulence between strains was observed and determined by culture and abortion rates. IP administration of C fetus subsp. venerealis to pregnant guinea pigs is a promising small animal model for the investigation of BGC abortion. (C) 2014 Elsevier Ltd. All rights reserved

Evolutionary conserved microRNAs are ubiquitously expressed compared to tick-specific miRNAs in the cattle tick Rhipicephalus (Boophilus) microplus

Background: MicroRNAs (miRNAs) are small non-coding RNAs that act as regulators of gene expression in eukaryotes modulating a large diversity of biological processes. The discovery of miRNAs has provided new opportunities to understand the biology of a number of species. The cattle tick, Rhipicephalus (Boophilus) microplus, causes significant economic losses in cattle production worldwide and this drives us to further understand their biology so that effective control measures can be developed. To be able to provide new insights into the biology of cattle ticks and to expand the repertoire of tick miRNAs we utilized Illumina technology to sequence the small RNA transcriptomes derived from various life stages and selected organs of R. microplus. Results: To discover and profile cattle tick miRNAs we employed two complementary approaches, one aiming to find evolutionary conserved miRNAs and another focused on the discovery of novel cattle-tick specific miRNAs. We found 51 evolutionary conserved R. microplus miRNA loci, with 36 of these previously found in the tick Ixodes scapularis. The majority of the R. microplus miRNAs are perfectly conserved throughout evolution with 11, 5 and 15 of these conserved since the Nephrozoan (640 MYA), Protostomian (620MYA) and Arthropoda (540 MYA) ancestor, respectively. We then employed a de novo computational screening for novel tick miRNAs using the draft genome of I. scapularis and genomic contigs of R. microplus as templates. This identified 36 novel R. microplus miRNA loci of which 12 were conserved in I. scapularis. Overall we found 87 R. microplus miRNA loci, of these 15 showed the expression of both miRNA and miRNA* sequences. R. microplus miRNAs showed a variety of expression profiles, with the evolutionary-conserved miRNAs mainly expressed in all life stages at various levels, while the expression of novel tick-specific miRNAs was mostly limited to particular life stages and/or tick organs. Conclusions: Anciently acquired miRNAs in the R. microplus lineage not only tend to accumulate the least amount of nucleotide substitutions as compared to those recently acquired miRNAs, but also show ubiquitous expression profiles through out tick life stages and organs contrasting with the restricted expression profiles of novel tick-specific miRNAs