Vector-borne pathogens impact public health, animal production, and animal welfare. Research on arthropod vectors such as mosquitoes, ticks, sandflies, and midges which transmit pathogens to humans and economically important animals is crucial for development of new control measures that target transmission by the vector. While insecticides are an important part of this arsenal, appearance of resistance mechanisms is increasingly common. Novel tools for genetic manipulation of vectors, use of Wolbachia endosymbiotic bacteria, and other biological control mechanisms to prevent pathogen transmission have led to promising new intervention strategies, adding to strong interest in vector biology and genetics as well as vector–pathogen interactions. Vector research is therefore at a crucial juncture, and strategic decisions on future research directions and research infrastructure investment should be informed by the research community. A survey initiated by the European Horizon 2020 INFRAVEC-2 consortium set out to canvass priorities in the vector biology research community and to determine key activities that are needed for researchers to efficiently study vectors, vector-pathogen interactions, as well as access the structures and services that allow such activities to be carried out. We summarize the most important findings of the survey which in particular reflect the priorities of researchers in European countries, and which will be of use to stakeholders that include researchers, government, and research organizations.

Theileria spp. are tick-borne protozoan parasites that infect a wide range of wild and domestic animals. In this study, the utility of xenosurveillance of blood-fed specimens of Culiseta annulata for detecting the presence of piroplasms in livestock was investigated. Blood-fed mosquitoes were collected at Elmley National Nature Reserve, Kent, United Kingdom. All specimens were morphologically identified, and DNA barcoding was used to confirm the morphological identification. Both the vertebrate host species and Theileria genome was detected within the bloodmeal by real-time PCR. Sequencing was used to confirm the identity of all amplicons. In total, 105 blood-fed mosquitoes morphologically identified as Cs. annulata were collected. DNA barcoding revealed that 102 specimens were Cs. annulata (99%), while a single specimen was identified as Anopheles messeae. Two specimens could not be identified molecularly due to PCR amplification failure. Blood meal analysis revealed that Cs. annulata fed almost exclusively on cattle at the collection site (n = 100). The application of a pan-piroplasm PCR detected 16 positive samples (15.2%) and sequence analysis of the amplicons demonstrated that the piroplasms present in the blood meal belonged to the Theileria orientalis group. This study demonstrates how xenosurveillance can be applied to detecting pathogens in livestock and confirms the presence of Theileria species in livestock from the United Kingdom.

The p17 protein of avian reovirus (ARV) causes cell cycle retardation in a variety of cell lines; however, the underlying mechanism(s) by which p17 regulates the cell cycle remains largely unknown. We demonstrate for the first time that p17 interacts with CDK1 and vimentin as revealed by reciprocal co-immunoprecipitation and GST pull-down assays. Both in vitro and in vivo studies indicated that direct interaction of p17 and CDK1/vimentin was mapped within the amino terminus (aa 1–60) of p17 and central region (aa 27–118) of CDK1/vimentin. Furthermore, p17 was found to occupy the Plk1-binding site within the vimentin, thereby blocking Plk1 recruitment to CDK1-induced vimentin phosphorylation at Ser 56. Interaction of p17 to CDK1 or vimentin interferes with CDK1-catalyzed phosphorylation of vimentin at Ser 56 and subsequently vimentin phosphorylation at Ser 82 by Plk1. Furthermore, we have identified upstream signaling pathways and cellular factor(s) targeted by p17 and found that p17 regulates inhibitory phosphorylation of CDK1 and blocks vimentin phosphorylation at Ser 56 and Ser 82. The p17-mediated inactivation of CDK1 is dependent on several mechanisms, which include direct interaction with CDK1, p17-mediated suppression of Plk1 by activating the Tpr/p53 and ATM/Chk1/PP2A pathways, and p17-mediated cdc25C degradation via an ubiquitin- proteasome pathway. Additionally, depletion of p53 with a shRNA as well as inhibition of ATM and vimentin by inhibitors diminished virus yield while Tpr and CDK1 knockdown increased virus yield. Taken together, results demonstrate that p17 suppresses both CDK1 and Plk1functions, disrupts vimentin phosphorylation, causes G2/M cell cycle arrest and thus benefits virus replication.

Ticks are vectors and reservoirs of many arboviruses pathogenic for humans or domestic animals; in addition, during bloodfeeding they can acquire and harbour pathogenic arboviruses normally transmitted by other arthropods such as mosquitoes. Tick cell and organ cultures provide convenient tools for propagation and study of arboviruses, both tick-borne and insect-borne, enabling elucidation of virus-tick cell interaction and yielding insight into the mechanisms behind vector competence and reservoir potential for different arbovirus species. The mosquito-borne zoonotic alphavirus Semliki Forest virus (SFV), which replicates well in tick cells, has been isolated from Rhipicephalus, Hyalomma, and Amblyomma spp. ticks removed from mammalian hosts in East Africa; however nothing is known about any possible role of ticks in SFV epidemiology. Here we present a light and electron microscopic study of SFV infecting cell lines and organ cultures derived from African Rhipicephalus spp. ticks. As well as demonstrating the applicability of these culture systems for studying virus-vector interactions, we provide preliminary evidence to support the hypothesis that SFV is not normally transmitted by ticks because the virus does not infect midgut cells.

While ticks have been known to harbor and transmit pathogenic arboviruses for over 80 years, the application of high-throughput sequencing technologies has revealed that ticks also appear to harbor a diverse range of endogenous tick-only viruses belonging to many different families. Almost nothing is known about these viruses; indeed, it is unclear in most cases whether the identified viral sequences are derived from actual replication-competent viruses or from endogenous virus elements incorporated into the ticks' genomes. Tick cell lines play an important role in virus discovery and isolation through the identification of novel viruses chronically infecting such cell lines and by acting as host cells to aid in determining whether or not an entire replication-competent, infective virus is present in a sample. Here, we review recent progress in tick-borne virus discovery and comment on the actual and potential applications for tick cell lines in this emerging research area.

Infectious bronchitis virus (IBV) causes infectious bronchitis in poultry, a respiratory disease that is a source of major economic loss to the poultry industry. Detection and the study of the molecular pathogenesis of the virus often involves the use of real-time quantitative PCR assays (qPCR). To account for error within the experiments, the levels of target gene transcription are normalised to that of suitable reference genes. Despite publication of the MIQE guidelines in 2009, single un-tested reference genes are often used for normalization of qPCR assays in avian research studies. Here we use the geNorm algorithm to identify suitable reference genes in different avian cell types during infection with apathogenic and pathogenic strains of IBV. We discuss the importance of selecting an appropriate experimental sample subset for geNorm analysis, and show the effect that this selection can have on resultant reference gene selection. The effects of inappropriate normalization on the transcription pattern of a cellular signalling gene, AKT1, and the interferon-inducible, MX1, were studied. We identify the possibility of the misinterpretation of qPCR data when an inappropriate normalisation strategy is employed. This is most notable when measuring the transcription of AKT1, where changes are minimal during infection.

The protective efficacy of a non-replicating Adenovirus serotype 5, expressing the immunogenic envelope glycoprotein B (Ad5-gB) of Marek’s disease virus, was investigated in a vaccine-challenge model for Marek’s disease in experimental chickens. In ovo vaccination with Ad5-gB, with or without a second vaccination posthatch, was compared with pCVI988 (a clone of the gold-standard CVI988 Marek’s disease vaccine). In ovo vaccination with Ad5-gB, without the second vaccination, gave a protective index of 37.5%, but did not reduce replication, shedding or transmission of virulent virus. In ovo vaccination followed by a post-hatch vaccination with Ad5-gB, was as protective as pCVI988 against mortality and Marek’s disease lesions (100% protection) and, like pCVI988, efficiently reduced the level of virulent virus in the blood of chickens. However, although this double-dose Ad5-gB vaccination delayed the onset of shedding of virulent virus, it did not inhibit shedding and was less effective than pCVI988 in reducing shedding and transmission of virulent virus. Further optimisation of Ad5-gB dose, administration route and time of vaccination could lead to trials as a potential vectored vaccine candidate for Marek’s disease, with a number of advantages over the current live cell-associated vaccines: no requirement for maintenance of a cold chain during vaccine preparation and administration, no horizontal spread, reduced selection pressure for highly virulent virus, and no possibility of reversion to virulence.

Rapid, reliable and accurate diagnostic methods provide essential support to programmes that monitor and control foot-and-mouth disease (FMD). While pan-specific molecular tests for FMD virus (FMDV) detection are well established and widely used in endemic and FMD-free countries, current serotyping methods mainly rely either on antigen detection ELISAs or nucleotide sequencing approaches. This report describes the development of a panel of serotype-specific real-time RT-PCR assays (rRT-PCR) tailored to detect FMDV lineages currently circulating in East Africa. These assays target sequences within the VP1-coding region that share high intra-lineage identity, but do not cross-react with FMD viruses from other serotypes that circulate in the region. These serotype-specific assays operate with the same thermal profile as the pan-diagnostic tests making it possible to run them in parallel to produce CT values comparable to the pan-diagnostic test detecting the 3D-coding region. These assays were evaluated alongside the established pan-specific molecular test using field samples and virus isolates collected from Tanzania, Kenya and Ethiopia that had been previously characterised by nucleotide sequencing. Samples (n = 71) representing serotype A (topotype AFRICA, lineage G-I), serotype O (topotypes EA-2 and EA-4), serotype SAT 1 (topotype I (NWZ)) and serotype SAT2 (topotype IV) were correctly identified with these rRT-PCR assays. Furthermore, FMDV RNA from samples that did not contain infectious virus could still be serotyped using these assays. These serotype-specific real-time RT-PCR assays can detect and characterise FMDVs currently circulating in East Africa and hence improve disease control in this region.

Release of sterile insects, the Sterile Insect Technique (SIT), can be an extremely effective and precise method of pest control. A study in BMC Biology from the New World screwworm SIT program and others shows that modern genetic methods can provide major improvements even to this well-established and highly successful SIT program.