Amoebic crab disease (ACD) in edible crab Cancer pagurus from the English Channel, UK.

The genera Paramoeba and Neoparamoeba (Amoebozoa, Dactylopodida, Paramoebidae) include well-known opportunistic pathogens associated with fish (N. peruans; amoebic gill disease), lobsters, molluscs and sea urchins, but only rarely with crabs (grey crab disease of blue crabs). Following reports of elevated post-capture mortality in edible crabs Cancer pagurus captured from a site within the English Channel fishery in the UK, a novel disease (amoebic crab disease, ACD) was detected in significant proportions of the catch. We present histopathological, transmission electron microscopy and molecular phylogenetic data, showing that this disease is defined by colonization of haemolymph, connective tissues and fixed phagocytes by amoeboid cells, leading to tissue destruction and presumably death in severely diseased hosts. The pathology was strongly associated with a novel amoeba with a phylogenetic position on 18S rRNA gene trees robustly sister to Janickina pigmentifera (which groups within the current circumscription of Paramoeba/Neoparamoeba), herein described as Janickina feisti n. sp. We provide evidence that J. feisti is associated with ACD in 50% of C. pagurus sampled from the mortality event. A diversity of other paramoebid sequence types, clustering with known radiations of N. pemaquidensis and N. aestuarina and a novel N. aestuarina sequence type, was detected by PCR in most of the crabs investigated, but their detection was much less strongly associated with clinical signs of disease. The discovery of ACD in edible crabs from the UK is discussed relative to published historical health surveys for this species.

Haplosporidium acetes n. sp. infecting the hepatopancreas of jelly prawns Acetes sibogae australis from Moreton Bay, Australia.

Wild Acetes sibogae australis from northern Moreton Bay, Australia displaying opacity of the hepatopancreas were sampled and examined histologically, revealing infection by multinucleate plasmodia of a haplosporidian-like parasite in the epithelial cells of the hepatopancreas. A morphological and phylogenetic investigation identified the parasite as a novel species of the order Haplosporida, and the parasite is described as Haplosporidium acetes n. sp. This is the first report of disease caused by a haplosporidian in wild Australian decapod crustaceans, and the first record of haplosporidiosis in sergestid shrimp. Infections of H. acetes were observed in all cell types (R, B, F and E) within the hepatopancreas. Infected epithelial cells became hypertrophied as they filled with haplosporidian parasites and, in heavy infections, caused almost complete displacement of normal hepatopancreas tissue. Although sporulation was not observed, infected jelly prawns appeared terminally diseased. Infections became grossly evident in around 5% of wild prawns during early autumn at a time of year when jelly prawn populations decline rapidly with decreasing water temperatures, however histopathology indicated at least 13% of apparently normal jelly prawns were also infected. Further studies are required in order to determine if this parasite influences jelly prawn population dynamics. In addition, we report co-infection of a novel microsporidian parasite in the Enterocytozoon Group Microsporidia (EGM) infecting nuclei of hepatopancreatic epithelial cells. The microsporidian was phylogenetically distinct from Enterocytozoon hepatopenaei (EHP) known to infect penaeid shrimp in Asia.

A seafood risk tool for assessing and mitigating chemical and pathogen hazards in the aquaculture supply chain.

Intricate links between aquatic animals and their environment expose them to chemical and pathogenic hazards, which can disrupt seafood supply. Here we outline a risk schema for assessing potential impacts of chemical and microbial hazards on discrete subsectors of aquaculture-and control measures that may protect supply. As national governments develop strategies to achieve volumetric expansion in seafood production from aquaculture to meet increasing demand, we propose an urgent need for simultaneous focus on controlling those hazards that limit its production, harvesting, processing, trade and safe consumption. Policies aligning national and international water quality control measures for minimizing interaction with, and impact of, hazards on seafood supply will be critical as consumers increasingly rely on the aquaculture sector to supply safe, nutritious and healthy diets.

The aquatic animal pandemic crisis.

The growth of aquaculture over the past 50 years has been accompanied by the emergence of aquatic animal diseases, many of which have spread to become pandemic in countries or continents. An analysis of 400 emerging disease events in aquatic animals that were logged by the Centre for Environment, Fisheries and Aquaculture Science between 2002 and 2017 revealed that more than half were caused by viruses. However, in molluscs, most events were parasitic. Categorising these events indicated that the key processes underpinning emergence were the movement of live animals and host switching. Profiles of key pathogens further illustrate the importance of wild aquatic animals as the source of new infections in farmed animals. It is also clear that the spread of new diseases through the largescale movement of aquatic animals for farming, for food and for the ornamental trade has allowed many to achieve pandemic status. Many viral pathogens of fish (e.g. infectious salmon anaemia, viral haemorrhagic septicaemia) and shrimp (e.g. white spot syndrome virus) affect a large proportion of the global production of key susceptible species. Wild aquatic animal populations have also been severely affected by pandemic diseases, best exemplified by Batrachochytrium dendrobatidis, a fungal infection of amphibians, whose emergence and spread were driven by the movement of animals for the ornamental trade. Batrachochytrium dendrobatidis is now widespread in the tropics and subtropics and has caused local extinctions of susceptible amphibian hosts. Given the rising demand for seafood, aquacultural production will continue to grow and diseases will continue to emerge. Some will inevitably achieve pandemic status, having significant impacts on production and trade, unless there are considerable changes in global monitoring and the response to aquatic animal diseases.

Au cours des 50 dernières années, la forte croissance qu'a connue l'aquaculture est allée de pair avec l'émergence de nombreuses maladies affectant les animaux aquatiques, dont certaines se sont propagées jusqu'à devenir pandémiques à l'échelle nationale ou continentale. L'analyse de 400 événements sanitaires survenus chez des animaux aquatiques et consignés entre 2002 et 2017 par le Centre for Environment, Fisheries and Aquaculture Science a déterminé l'origine virale de plus de la moitié d'entre eux. Toutefois, chez les mollusques la plupart des événements analysés étaient d'ordre parasitaire. Le classement des événements par catégories a montré que les principaux processus sous-jacents à cette émergence étaient liés aux transferts d'animaux vivants et à la colonisation de nouveaux hôtes par les agents pathogènes. Les profils des agents pathogènes majeurs illustrent le rôle des espèces aquatiques sauvages en tant que sources d'infections nouvelles chez les animaux aquatiques d'élevage. Il apparaît clairement que la propagation de nouvelles maladies à la faveur des transferts massifs d'animaux aquatiques à des fins d'élevage, de production alimentaire ou de commerce d'espèces d'ornement a conféré un statut pandémique à nombre de ces maladies. De nombreux virus affectant les poissons (par ex., le virus de l'anémie infectieuse du saumon, le virus de la septicémie hémorragique virale) et les crevettes (par ex., le virus du syndrome des points blancs) ont une incidence majeure sur de vastes segments de la production mondiale d'espèces sensibles cruciales. Les populations sauvages d'animaux aquatiques sont également touchées par des maladies pandémiques, dont l'exemple type est l'infection à Batrachochytrium dendrobatidis, une affection fongique des amphibiens dont l'émergence et la propagation sont le fruit des transferts d'animaux aquatiques destinés au commerce aquariophile. Batrachochytrium dendrobatidis est désormais largement présent dans les eaux tropicales et subtropicales où il est responsable d'extinctions locales parmi les espèces d'amphibiens sensibles. La croissance de la production aquacole se poursuivra afin de répondre à une demande toujours plus forte en poissons et fruits de mer, entraînant l'émergence continue de nouvelles maladies. Si des changements déterminants ne sont pas introduits dans la surveillance exercée au niveau mondial sur les maladies des animaux aquatiques et dans la réponse qui leur est apportée, certaines de ces maladies vont inéluctablement acquérir une dimension pandémique avec des conséquences importantes sur la production et le commerce.

El crecimiento de la acuicultura en los últimos 50 años se ha acompañado de la aparición de enfermedades de los animales acuáticos, que en muchos casos se han propagado hasta llegar a ser pandémicas en ciertos países o continentes. Tras analizar 400 episodios de enfermedades emergentes de animales acuáticos registrados entre 2002 y 2017 por el Centre for the Environment, Fisheries and Aquaculture Science, los autores constataron que más de la mitad de esos episodios fueron causados por virus, si bien en el caso de los moluscos la mayoría de ellos eran parasitarios. De la clasificación de esos episodios se desprende que los procesos básicos que subyacen a su aparición son los desplazamientos de animales vivos y los cambios de anfitrión. El perfil de los principales patógenos revela además la importancia que revisten los animales acuáticos silvestres como fuente de nuevas infecciones de los animales de acuicultura. También está claro que la propagación de nuevas enfermedades por el movimiento a gran escala de animales acuáticos con fines de producción acuícola, consumo alimentario o comercio de animales ornamentales ha propiciado que muchas de ellas adquieran carácter pandémico. Muchos patógenos víricos de los peces (como el virus de la anemia infecciosa del salmón o el de la septicemia hemorrágica viral) y camarones (como el virus del síndrome de las manchas blancas) afectan a una gran parte de la producción mundial de las principales especies sensibles. Las poblaciones silvestres de animales acuáticos también se han visto afectadas de gravedad por enfermedades pandémicas, como ejemplifica perfectamente la infección por Batrachochytrium dendrobatidis, micosis de los anfibios cuya aparición y propagación fue alimentada por el comercio y el consiguiente movimiento de animales con fines ornamentales. Este hongo, muy extendido ahora en las regiones tropicales y subtropicales, ha causado la extinción en ciertas áreas de especies anfibias sensibles. Habida cuenta de la creciente demanda de alimentos de origen marino, la producción acuícola seguirá creciendo y también seguirán surgiendo enfermedades. Inevitablemente, algunas de ellas se harán pandémicas y resultarán muy dañinas para la producción y el comercio, a menos que haya cambios de calado en los sistemas mundiales de vigilancia y respuesta ante las enfermedades de los animales acuáticos.

Characterization of microsporidian Ameson herrnkindi sp. nov. infecting Caribbean spiny lobsters Panulirus argus.

The Caribbean spiny lobster Panulirus argus supports a large and valuable fishery in the Caribbean Sea. In 2007-2008, a rare microsporidian parasite with spore characteristics typical of the Ameson genus was detected in 2 spiny lobsters from southeast Florida (FL). However, the parasite species was not confirmed by molecular analyses. To address this deficiency, reported here are structural and molecular data on single lobsters displaying comparable 'cotton-like' abdominal muscle containing ovoid microsporidian spores found at different locations in FL in 2014 and 2018 and in Saint Kitts and Nevis Islands in 2017. In the lobster from 2014, multiple life stages consistent with an Ameson-like monokaryotic microsporidian were detected by transmission electron microscopy. A partial (1228 bp) small subunit (SSU) rRNA gene sequence showed each microsporidia to be identical and positioned it closest phylogenetically to Ameson pulvis in a highly supported clade also containing A. michaelis, A. metacarcini, A. portunus, and Nadelspora canceri. Using ecological, pathological, ultrastructural, and molecular data, the P. argus microsporidian has been assigned to a distinct species: Ameson herrnkindi.

Evidence for trophic transfer of Inodosporus octospora and Ovipleistophora arlo n. sp. (Microsporidia) between crustacean and fish hosts.

Within aquatic habitats, the hyper-abundant Order Crustacea appear to be the predominant host group for members of the Phylum Microsporidia. The musculature, a common site of infection, provides access to biochemical (carbohydrate-rich) and physiological (mitochondria-rich) conditions conducive to prolific parasite replication and maturation. The significant proportion of body plan devoted to skeletal musculature in Crustacea provides the location for a highly efficient intracellular parasite factory. In this study, we utilize histological, ultrastructural and phylogenetic evidence to describe a previously known (Inodosporus octospora) and novel (Ovipleistophora arlo n. sp.) microsporidian parasites infecting the musculature of the common prawn (Palaemon serratus) from the same site, at the same time of year. Despite similar clinical signs of infection, both parasites are otherwise distinct in terms of pathogenesis, morphology and phylogeny. Based upon partial subunit ribosomal RNA (SSU rDNA) sequence, we show that that I. octospora may be identical to a Kabatana sp. previously described infecting two-spot goby (Gobiusculus flavescens) in Europe, or at least that Inodosporus and Kabatana genera are synonyms. In addition, SSU rDNA sequence for O. arlo places it within a distinct clade containing Ovipleistophora mirandellae and Ovipleistophora ovariae, both infecting the oocytes of freshwater fish in Europe. Taken together, our data provide strong evidence for trophic-transfer between crustacean and fish hosts for two different microsporidians within clade 5 of the phylum. Furthermore, it demonstrates that morphologically and phylogenetically distinct microsporidians can infect the same tissues of the same host species to impart clinical signs which mimic infection with the other.

A taxonomic review of viruses infecting crustaceans with an emphasis on wild hosts.

Numerous infections by viral pathogens have been described from wild and cultured crustacean hosts, yet relatively few of these pathogens have been formally characterised and classified. To date viruses have generally been tentatively assigned to families based upon morphological and developmental characteristics and their location of infection within the host cell. Often nucleotide sequence information is unavailable. Some of these viral infections have caused well-documented devastating consequences on the global crustacean farming industry whilst their effects on wild populations remain largely unstudied. This paper provides an up to date review of all known viruses described infecting crustacean hosts. Full characterisation and harmonisation of these descriptions utilising specifications proposed by the International Committee on Taxonomy of Viruses (ICTV) is required to synonymise numerous examples of differential naming or abbreviation of naming, of the same virus in some cases. Development and application of techniques such as viral purification and high throughput sequencing of viral genomes will assist with these full descriptions and, provide appropriate diagnostic targets for surveillance of known and novel relatives. This review also highlights the importance of comparative study with viruses infecting insects and other arthropods to assist this process.

Validation of a microdose probe drug cocktail for clinical drug interaction assessments for drug transporters and CYP3A.

A microdose cocktail containing midazolam, dabigatran etexilate, pitavastatin, rosuvastatin, and atorvastatin has been established to allow simultaneous assessment of a perpetrator impact on the most common drug metabolizing enzyme, cytochrome P450 (CYP)3A, and the major transporters organic anion-transporting polypeptides (OATP)1B, breast cancer resistance protein (BCRP), and MDR1 P-glycoprotein (P-gp). The clinical utility of these microdose cocktail probe substrates was qualified by conducting clinical drug interaction studies with three inhibitors with different in vitro inhibitory profiles (rifampin, itraconazole, and clarithromycin). Generally, the pharmacokinetic profiles of the probe substrates, in the absence and presence of the inhibitors, were comparable to their reported corresponding pharmacological doses, and/or in agreement with theoretical expectations. The exception was dabigatran, which resulted in an approximately twofold higher magnitude for microdose compared to conventional dosing, and, thus, can be used to flag a worst-case scenario for P-gp. Broader application of the microdose cocktail will facilitate a more comprehensive understanding of the roles of drug transporters in drug disposition and drug interactions.

Hyperspora aquatica n.gn., n.sp. (Microsporidia), hyperparasitic in Marteilia cochillia (Paramyxida), is closely related to crustacean-infecting microspordian taxa.

The Paramyxida, closely related to haplosporidians, paradinids, and mikrocytids, is an obscure order of parasitic protists within the class Ascetosporea. All characterized ascetosporeans are parasites of invertebrate hosts, including molluscs, crustaceans and polychaetes. Representatives of the genus Marteilia are the best studied paramyxids, largely due to their impact on cultured oyster stocks, and their listing in international legislative frameworks. Although several examples of microsporidian hyperparasitism of paramyxids have been reported, phylogenetic data for these taxa are lacking. Recently, a microsporidian parasite was described infecting the paramyxid Marteilia cochillia, a serious pathogen of European cockles. In the current study, we investigated the phylogeny of the microsporidian hyperparasite infecting M. cochillia in cockles and, a further hyperparasite, Unikaryon legeri infecting the digenean Meiogymnophallus minutus, also in cockles. We show that rather than representing basally branching taxa in the increasingly replete Cryptomycota/Rozellomycota outgroup (containing taxa such as Mitosporidium and Paramicrosoridium), these hyperparasites instead group with other known microsporidian parasites infecting aquatic crustaceans. In doing so, we erect a new genus and species (Hyperspora aquatica n. gn., n.sp.) to contain the hyperparasite of M. cochillia and clarify the phylogenetic position of U. legeri. We propose that in both cases, hyperparasitism may provide a strategy for the vectoring of microsporidians between hosts of different trophic status (e.g. molluscs to crustaceans) within aquatic systems. In particular, we propose that the paramyxid hyperparasite H. aquatica may eventually be detected as a parasite of marine crustaceans. The potential route of transmission of the microsporidian between the paramyxid (in its host cockle) to crustaceans, and, the 'hitch-hiking' strategy employed by H. aquatica is discussed.

Single and multi-gene phylogeny of Hepatospora (Microsporidia) - a generalist pathogen of farmed and wild crustacean hosts.

Almost half of all known microsporidian taxa infect aquatic animals. Of these, many cause disease in arthropods. Hepatospora, a recently erected genus, infects epithelial cells of the hepatopancreas of wild and farmed decapod crustaceans. We isolated Hepatospora spp. from three different crustacean hosts, inhabiting different habitats and niches; marine edible crab (Cancer pagurus), estuarine and freshwater Chinese mitten crab (Eriocheir sinensis) and the marine mussel symbiont pea crab (Pinnotheres pisum). Isolates were initially compared using histology and electron microscopy revealing variation in size, polar filament arrangement and nuclear development. However, sequence analysis of the partial SSU rDNA gene could not distinguish between the isolates (~99% similarity). In an attempt to resolve the relationship between Hepatospora isolated from E. sinensis and C. pagurus, six additional gene sequences were mined from on-going unpublished genome projects (RNA polymerase, arginyl tRNA synthetase, prolyl tRNA synthetase, chitin synthase, beta tubulin and heat shock protein 70). Primers were designed based on the above gene sequences to analyse Hepatospora isolated from pea crab. Despite application of gene sequences to concatenated phylogenies, we were unable to discriminate Hepatospora isolates obtained from these hosts and concluded that they likely represent a single species or, at least subspecies thereof. In this instance, concatenated phylogenetic analysis supported the SSU-based phylogeny, and further, demonstrated that microsporidian taxonomies based upon morphology alone are unreliable, even at the level of the species. Our data, together with description of H. eriocheir in Asian crab farms, reveal a preponderance for microvariants of this parasite to infect the gut of a wide array of decapods crustacean hosts and the potential for Hepatospora to exist as a cline across wide geographies and habitats.

Quantitation of anacetrapib, stable-isotope labeled-anacetrapib (microdose), and four metabolites in human plasma using liquid chromatography tandem mass spectrometry.

An ultra-high performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous determination of (4S,5R)-5-[3,5-bis (trifluoromethyl)phenyl]-3-{[4'-fluoro-5'-isopropyl-2'-methoxy-4-(trifluoromethyl)biphenyl-2-yl] methyl}-4-methyl-1,3-oxazolidin-2-one (anacetrapib, I) and [(13)C5(15)N]-anacetrapib, II in human plasma has been developed to support a clinical study to determine the absolute bioavailability of I. The analytes and the stable-isotope labeled internal standard ([(13)C7(15)N(2)H7]-anacetrapib, III) were extracted from 100µL of human plasma by liquid-liquid extraction using 20/80 isopropyl alcohol/hexane (v/v). The chromatographic separation of the analytes was achieved using Waters BEH Shield RP 18 (50×2.1mm×1.7µm) column and mobile phase gradient of 0.1% formic acid in water (Solvent A) and 0.1% formic acid in acetonitrile (Solvent B) at 0.6mL/min flow rate. The MS/MS detection was performed on AB Sciex 5000 or AB 5500 in positive electrospray ionization mode, operated in selected reaction monitoring mode. The assay was validated in the concentration range 1-2000ng/mL for I; and a lower curve range, 0.025-50ng/mL for II. In addition to the absolute bioavailability determination, it was desired to better elucidate the pharmacokinetic behavior of several hydroxylated metabolites of I. Toward this end, two exploratory assays for the hydroxy metabolites of I were qualified in the concentration range 0.5-500ng/mL. All metabolites were separated on a Supelco Ascentis Express Phenyl-Hexyl (50×2.1mm, 2.7µm) column. Metabolite M4 was analyzed in the negative mode with a mobile phase consisting of a gradient mixture of water (A) and acetonitrile (B). The other three metabolites, M1-M3 were analyzed in the positive mode using a mobile phase gradient of water with 0.1% formic acid (A) and acetonitrile with 0.1% formic acid (B). The assays were utilized to support a clinical study in which a microdosing approach was used to determine the pharmacokinetics of anacetrapib and its metabolites.

Paradoxium irvingi n.gen. n.sp. (Microsporidia) infecting the musculature of European pink shrimp Pandalus montagui.

This paper utilises histological, ultrastructure and molecular phylogenetic data to describe a novel genus and species (Paradoxium irvingi n.gen., n.sp.) within clade 5 of the phylum Microsporidia. The parasite infects the musculature of the pink shrimp Pandalus montagui captured from United Kingdom waters. The novel microsporidium is morphologically and phylogenetically dissimilar to its nearest phylogenetic branch relative Thelohania butleri infecting the sister shrimp taxon Pandalus jordani. Furthermore, it is morphologically distinct from the type species of the genus Thelohania, Thelohania giardi infecting European brown shrimp Crangon crangon. Since phylogenetic data pertaining to type T. giardi is not currently available, our discovery places some doubt on the likelihood that T. butleri represents the proposed surrogate for the type taxon. Further it demonstrates potential for significant morphological plasticity in this clade of muscle-infecting microsporidians of crustaceans which contains the genera Myospora, Cucumispora, Thelohania, and now Paradoxium. Since it cannot be stated with certainty that T. butleri (or other taxa within the clade) represent true close relatives of T. giardi, clarity on this issue will only occur with re-discovery and genotyping of type T. giardi infecting C. crangon from European waters.

Listerial brainstem encephalitis--treatable, but easily missed.

Listerial brainstem encephalitis (LBE) is an uncommon form of listerial central nervous system infection that progresses rapidly and is invariably fatal unless detected and treated early. We report on six adult patients with LBE, of whom five were managed or co-managed by our unit during the period January - June 2012. All presented with a short prodromal illness followed by a combination of brainstem signs, including multiple cranial nerve palsies with emphasis on the lower cranial nerves, ataxia, motor and sensory long-tract signs, a depressed level of consciousness and apnoea. In two cases the diagnosis was delayed with adverse outcomes. LBE may be difficult to diagnose: clinicians may not be aware of this condition, the brainstem location may not be recognised readily, general markers of inflammation such as the erythrocyte sedimentation rate, C-reactive protein level or white cell count may be normal, and the cerebrospinal fluid is typically normal or there are only mild and nonspecific findings. Serological tests are unreliable, and diagnosis is achieved through blood cultures, magnetic resonance imaging and clinical recognition.

An experimental means of transmitting pancreas disease in Atlantic salmon Salmo salar L. fry in freshwater.

A challenge model for pancreas disease in Atlantic salmon, Salmo salar L. fry, was developed comparing two salmonid alphavirus (SAV) subtypes: SAV1 and SAV5. Viral doses of 3 × 10(5) TCID50  mL(-1) for SAV1 and 3 × 10(4) for SAV5 were tested in triplicate tanks, each containing 450 salmon fry. Cumulative mortalities of 1.2% were recorded. Titres of virus recovered from the mortalities ranged from 10(2) to 10(7) TCID50  mL(-1) . Fry were sampled at 3, 5 and 7.5 weeks post-challenge. Sampling after 3 weeks revealed a high prevalence of infection in the absence of clinical signs, and infectious virus was recovered from 80% and 43% of sampled fry infected with SAV1 and SAV5, respectively. After 5 weeks pancreas, heart and red skeletal muscle lesions were generally observed, whilst degeneration in white skeletal muscle was observed only in fish infected with SAV1. In situ hybridisation confirmed the presence of viral genome in infected pancreas, heart and muscle. After 7.5 weeks, infectious virus (both isolates) was recovered from 13.3% of the fish sampled, with a viral titre of 10(2) TCID50  mL(-1) . Clearly, salmon fry are susceptible to SAV infection and pancreas disease.

Areospora rohanae n.gen. n.sp. (Microsporidia; Areosporiidae n. fam.) elicits multi-nucleate giant-cell formation in southern king crab (Lithodes santolla).

This paper utilises histological, ultrastructure and molecular phylogenetic data to describe a novel genus and species (Areospora rohanae n.gen., n.sp.) within the phylum Microsporidia. Phylogenetic and morphological distinction from other known lineages within the phylum also provide strong support for erection of a new family (Areosporiidae n. fam) to contain the parasite. Recognised via lesions observed by workers in king crab processing facilities in southern Chile, the parasite elicits giant cell formation in infected crabs. Merogony within haemocytes and fixed phagocytes proceeds apparent fusion of infected cells to produce multinucleate syncitia in which further development of the parasite occurs. Subsequent recruitment of adjacent cells within the haemal spaces of the hepatopancreas, the podocytes of the gill, and particularly in the subcuticular connective tissues, characterises the pathogenesis of A. rohanae. In late stages of infection, significant remodelling of the subcuticular tissues corresponds to the clinical lesions observed within processing plants. Sporogony of A. rohanae also occurs within the syncitial cytoplasm and culminates in production of bizarre spores, ornamented with distinctive tubular bristles. Spores occur in sets of 8 within a sporophorous vesicle. The description of A. rohanae offers considerable insight into the pathogenesis of giant-cell forming Microsporidia, signifies a new lineage of giant-cell forming Microsporidia in marine hosts, and may reflect emergence of a commercially-significant pathogen in the southern ocean Lithodes santolla fishery.

Hydrogen peroxide production and free radical-mediated cell stress in Mycoplasma bovis pneumonia.

Mycoplasma bovis causes chronic pneumonia and polyarthritis in feedlot cattle. M. bovis infects the lungs of most feedlot cattle, but the majority of calves never develop disease. Competing explanations are that some strains of M. bovis are more virulent than others or, alternatively, that calves require some other abnormality to be present in order for M. bovis to cause disease. We hypothesize that H2O2 production is an important virulence factor of M. bovis, causing oxidative injury to lung tissue. A second hypothesis is that isolates associated with caseonecrotic bronchopneumonia have an increased capacity for H2O2 production. Immunohistochemical markers of oxidative stress (4-hydroxynonenal, HN) and nitrative stress (3-nitrotyrosine, NT) were compared in lungs of calves with caseonecrotic bronchopneumonia characteristic of M. bovis infection, with other forms of bronchopneumonia or with non-inflamed lungs. HN and NT were identified in M. bovis pneumonia, mainly in foci of caseous necrosis. HN was not observed in inflamed non-necrotic tissue in lesions typical of pneumonic pasteurellosis. H2O2 production by M. bovis was identified, but the levels did not differ in isolates from calves with caseonecrotic bronchopneumonia compared with those with non-inflamed lungs or other forms of pneumonia. These findings provide evidence that oxidative and nitrative injury contribute to the formation of the caseonecrotic lesions that are characteristic of M. bovis pneumonia and that production of H2O2 by M. bovis may contribute to this oxidative injury.

Thrombolysis risk prediction: applying the SITS-SICH and SEDAN scores in South African patients.

At present, the only specific medical treatment for acute ischaemic stroke is intravenous administration of recombinant tissue plasminogen activator within 4.5 hours of stroke onset. In the last year, two scores for risk stratification of intracranial haemorrhage have been derived from multicentric European trial groups, the Safe Implementation of Treatment in Stroke - Symptomatic IntraCerebral Haemorrhage risk score (SITS-SICH) and the SEDAN score. The aim of this study was to pilot their use in a cohort of patients treated at a South African tertiary hospital. Prospectively collected data were used from a cohort of 41 patients who underwent thrombolysis at Groote Schuur Hospital from 2000 to 2012. Computerised tomography brain imaging was available for review in 23 of these cases. The SITS-SICH and SEDAN scores were then applied and risk prediction was compared with outcomes. Two patients suffered symptomatic intracranial haemorrhage (SICH), representing 4.9% (95% CI: 0-11.5%) of the cohort. This was comparable to the SICH rate in both the SITS-SICH (5.1%) and SEDAN (6.5%) cohorts. Patient scores in the Groote Schuur Hospital cohort appeared similar to those of the validation cohorts of both SITS-SICH and SEDAN. With increasing use of thrombolysis in a resource-constrained setting, these scores represent a potentially useful tool in patient selection of those most likely to benefit from intravenous thrombolysis, reducing risk for SICH and with the added benefit of curtailing cost.

Baseline histopathological survey of a recently invading island population of 'killer shrimp', Dikerogammarus villosus.

Dikerogammarus villosus, an invasive amphipod, has recently been detected in UK freshwaters. To assess the potential for pathogen introduction with the invader, a year-long histopathology survey of the D. villosus population inhabiting the initial site of detection (Grafham Water, Cambridgeshire, UK) was conducted. Additional samples were collected from 2 other subsequently identified populations within the UK (Cardiff Bay and Norfolk Broads), and from established populations in France (River Rhine) and Poland (River Vistula). The data revealed a range of pathogens and commensals. Several pathogens occurring within continental populations were not present within the UK populations. Microsporidian parasites and a novel viral pathogen were amongst those not observed in the UK. The absence of these pathogens at UK sites may therefore impart significant survival advantages to D. villosus over native fauna, thereby increasing its success as an invader. The contrast in pathogen profile between UK and continental-invasive populations of D. villosus provides preliminary evidence for so-called 'enemy release' in UK populations of D. villosus and is suggestive of single-point introductions, rather than continual incursion events as previously observed throughout its continental invasive range. This baseline survey provides important data on the pathogen and commensal profile of a high-impact, invasive species early in its invasion history of the UK. It can be utilised to assess potential for temporal pathogen acquisition by non-native invasive aquatic species and to investigate competitive advantages placed upon this invader due to absence of important pathogens experienced within its native range.

Haplosporidium littoralis sp. nov.: a crustacean pathogen within the Haplosporida (Cercozoa, Ascetosporea).

Previously, we described the pathology and ultrastructure of an apparently asporous haplosporidian-like parasite infecting the common shore crab Carcinus maenas from the European shoreline. In the current study, extraction of genomic DNA from the haemolymph, gill or hepatopancreas of infected C. maenas was carried out and the small subunit ribosomal DNA (SSU rDNA) of the pathogen was amplified by PCR before cloning and sequencing. All 4 crabs yielded an identical 1736 bp parasite sequence. BLAST analysis against the NCBI GenBank database identified the sequence as most similar to the protistan pathogen group comprising the order Haplosporida within the class Ascetosporea of the phylum Cercozoa Cavalier-Smith, 1998. Parsimony analysis placed the crab pathogen within the genus Haplosporidium, sister to the molluscan parasites H. montforti, H. pickfordi and H. lusitanicum. The parasite infecting C. maenas is hereby named as Haplosporidium littoralis sp. nov. The presence of a haplosporidian parasite infecting decapod crustaceans from the European shoreline with close phylogenetic affinity to previously described haplosporidians infecting molluscs is intriguing. The study provides important phylogenetic data for this relatively understudied, but commercially significant, pathogen group.