Who Is Dermanyssus gallinae? Genetic Structure of Populations and Critical Synthesis of the Current Knowledge

Despite the economic and animal welfare importance of the Poultry Red Mite Dermanyssus gallinae, its genetic structure has been studied in a scattered way so far. The prophylaxis and control of such a globally distributed ectoparasite can be significantly improved by understanding its genetic population structure (composition in species and intraspecific variants). The present study aims to establish a rigorous framework for characterizing the neutral genetic structure of D. gallinae based on a literature review combined with an integrative analysis of the data available in GenBank on population-level nucleotide sequence diversity supplemented by a new dataset. The integrative analysis was conducted on sequence data extracted from GenBank coupled with new sequences of two fragments of the mitochondrial gene encoding Cytochrome Oxidase I (CO1) as well as of an intron of the nuclear gene encoding Tropomyosin (Tpm) from several PRM populations sampled from European poultry farms. Emphasis was placed on using the mitochondrial gene encoding CO1 on which the main universal region of DNA barcoding in animals is located. The species D. gallinae sensu lato is a species complex, encompassing at least two cryptic species, i.e., not distinguishable by morphological characters: D. gallinae sensu stricto and D. gallinae L1. Only D. gallinae s.s. has been recorded among the populations sampled in poultry farms worldwide. Current knowledge suggests they are structured in three mitochondrial groups (haplogroups A, B, and C). Haplogroup A is cosmopolitan, and the other two present slightly contrasted distributions (B rather in the northern part of Europe, C most frequently found in the southern part). Recent data indicate that a dynamic geographic expansion of haplogroup C is underway in Europe. Our results also show that NUMT (nuclear mitochondrial DNA) pseudogenes have generated artifactual groups (haplogroups E and F). It is important to exclude these artifact groups from future analyses to avoid confusion. We provide an operational framework that will promote consistency in the analysis of subsequent results using the CO1 fragment and recommendations for future analyses

Plumo: An Ultralight Blockchain Client

Syncing the latest state of a blockchain can be a resource-intensive task, driving (especially mobile) end users towards centralized services offering instant access. To expand full decentralized access to anyone with a mobile phone, we introduce a consensus-agnostic compiler for constructing ultralight clients, providing secure and highly efficient blockchain syncing via a sequence of SNARK-based state transition proofs, and prove its security formally. Instantiating this, we present Plumo, an ultralight client for the Celo blockchain capable of syncing the latest network state summary in just a few seconds even on a low-end mobile phone. In Plumo, each transition proof covers four months of blockchain history and can be produced for just $25 USD of compute. Plumo achieves this level of efficiency thanks to two new SNARK-friendly constructions, which may also be of independent interest: a new BLS-based offline aggregate multisignature scheme in which signers do not have to know the members of their multisignature group in advance, and a new composite algebraic-symmetric cryptographic hash function

Should the poultry red mite Dermanyssus gallinae be of wider concern for veterinary and medical science?

The poultry red mite Dermanyssus gallinae is best known as a threat to the laying-hen industry; adversely affecting production and hen health and welfare throughout the globe, both directly and through its role as a disease vector. Nevertheless, D. gallinae is being increasingly implemented in dermatological complaints in non-avian hosts, suggesting that its significance may extend beyond poultry. The main objective of the current work was to review the potential of D. gallinae as a wider veterinary and medical threat. Results demonstrated that, as an avian mite, D. gallinae is unsurprisingly an occasional pest of pet birds. However, research also supports that these mites will feed from a range of other animals including: cats, dogs, rodents, rabbits, horses and man. We conclude that although reported cases of D. gallinae infesting mammals are relatively rare, when coupled with the reported genetic plasticity of this species and evidence of permanent infestations on non-avian hosts, potential for host-expansion may exist. The impact of, and mechanisms and risk factors for such expansion are discussed, and suggestions for further work made. Given the potential severity of any level of host-expansion in D. gallinae, we conclude that further research should be urgently conducted to confirm the full extent of the threat posed by D. gallinae to (non-avian) veterinary and medical sectors

Echinococcus multilocularis-adaptation of a worm egg isolation procedure coupled with a multiplex PCR assay to carry out large-scale screening of red foxes (Vulpes vulpes) in Norway

Echinococcus multilocularis, causing alveolar echinococcosis in humans, is a highly pathogenic emerging zoonotic disease in central Europe. The gold standard for the identification of this parasite in the main host, the red fox, namely identification of the adult parasite in the intestine at necropsy, is very laborious. Copro-enzyme-linked immunosorbent assay (ELISA) with confirmatory polymerase chain reaction (PCR) has been suggested as an acceptable alternative, but no commercial copro-ELISA tests are currently available and an in-house test is therefore required. Published methods for taeniid egg isolation and a multiplex PCR assay for simultaneous identification of E. multilocularis, E. granulosus and other cestodes were adapted to be carried out on pooled faecal samples from red foxes in Norway. None of the 483 fox faecal samples screened were PCR-positive for E. multilocularis, indicating an apparent prevalence of between 0% and 1.5%. The advantages and disadvantages of using the adapted method are discussed as well as the results pertaining to taeniid and non-taeniid cestodes as identified by multiplex PCR

Why is Southern African canine babesiosis so virulent? An evolutionary perspective

<p>Abstract</p> <p>Canine babesiosis is a common, highly virulent disease in Southern Africa with even pups and juveniles being severely affected. This contrasts with bovine babesiosis, for example, where host, parasite and vector co-evolved and young animals develop immunity after infection without showing clinical signs. <it>Babesia rossi</it>, the main causative organism of canine babesiosis in sub-Saharan Africa, was first described from a side-striped jackal (<it>Canis adustus</it>) in Kenya. Although data are meagre, there is evidence that indigenous African canids, such as jackals and wild dogs (<it>Lycaon pictus</it>), can harbour the parasite without showing untoward effects. Dogs are not indigenous to Africa. The vast majority of dogs presented at veterinary facilities in South Africa represent recently introduced European, Asian or American breeds. The contention is that <it>B. rossi </it>is a new challenge to which these dogs have not adapted. With intensive treatment of clinical cases, natural selection is effectively negated and the status quo will probably be maintained indefinitely. It is postulated that <it>Babesia vogeli</it>, which frequently results in unapparent infections or mild manifestations in dogs, represents or is closely related to the ancestral form of the canine parasite, possibly originating from wolves (<it>Canis lupus</it>).</p