Nocardiosis in freshwater reared Chinook salmon (Oncorhynchus tshawytscha).

CASE HISTORY: An investigation was conducted to identify the cause of mortalities in freshwater reared Chinook salmon (Oncorhynchus tshawytscha). Mortalities occurred in juvenile salmon, at a salmon rearing facility in the South Island of New Zealand. The affected fish were from a pen inside the facility with no surrounding pens or other year classes affected. CLINICAL FINDINGS: Clinically affected fish presented with skin lesions. The majority of skin lesions were unruptured, boil-like, raised circular masses up to 4 cm in diameter, particularly on the dorsolateral aspects and the flank. A number of fish presented with large ulcers resulting from rupturing of the raised lesions described above. This clinical presentation showed similarities to that of furunculosis caused by typical Aeromonas salmonicida, a bacterium exotic to New Zealand. LABORATORY FINDINGS: Samples were taken from two representative fish in the field for histopathology, bacterial culture and molecular testing. Histopathological findings included granulomatous lesions in the kidney, liver, spleen and muscle. When stained with Fite-Faraco modified acid fast stain filamentous branching rods were identified within these granulomas. Following bacterial culture of kidney swabs pure growth of small white matt adherent colonies was observed. This isolate was identified as a Nocardia species by biochemical testing and nucleotide sequencing of the partial 16S rRNA gene. All samples were negative for A. salmonicida based on bacterial culture and PCR testing. DIAGNOSIS: Nocardiosis caused by a Nocardia species. CLINICAL RELEVANCE: Nocardiosis in these fish was caused by a previously undescribed Nocardia species that differs from the species known to be pathogenic to fish: N. asteroides, N. salmonicida and N. seriole. This bacterium is likely to be a new or unnamed environmental species of Nocardia that has the potential to cause disease in Chinook salmon under certain conditions. The clinical presentation of this Nocardia species manifested as raised, boil-like skin lesions which has similarities to the presentation of furunculosis caused by the bacterium typical A. salmonicida, a species exotic to New Zealand.

Isolation of Tasmanian Rickettsia-like organism (RLO) from farmed salmonids: identification of multiple serotypes and confirmation of pathogenicity.

Atlantic salmon Salmo salar L. farmed in south-east Tasmania, Australia, are susceptible to infection by the Tasmanian Rickettsia-like organism (TRLO), a Gram-negative bacterium. Here, we report the first isolation of TRLO from south-east Tasmania in pure culture and show that the bacterium is culturable on both specialised enriched agar and in cell culture using the CHSE-214 cell line. In vitro cultured TRLO was used to reproducibly elicit disease in Atlantic salmon parr held in fresh water. In inoculated fish, TRLO was observed intracytoplasmically in peripheral blood leucocytes, suggesting that these cells are responsible for haematogenous dispersal of the bacterium within the host. Fish with experimentally induced disease presented with gross and histopathological changes similar to TRLO-infected fish at commercial marine farms. TRLO was also isolated in culture from farmed Atlantic salmon in the Tamar River and Macquarie Harbour production areas in Tasmania, both of which have no history of TRLO-associated disease. These TRLO isolates appear to be serologically distinct from each other as well as from isolates obtained from south-east Tasmania, linking each serotype to a specific geographical location within Tasmania. Despite the lack of clinical evidence of TRLO-linked disease in fish grown in the Tamar River and Macquarie Harbour, experimental infection trials demonstrably showed the pathogenic potential of these TRLO serovars. Together, these data provide evidence that TRLO is a fastidious, facultative intracellular bacterium and confirm TRLO as a pathogen of Atlantic salmon, causing a disease designated Tasmanian salmonid rickettsiosis.

A biobank analysis of prognostic biomarkers of the systemic inflammatory response in patients presenting with malignancy of undefined primary origin.

BACKGROUND: Survival prediction in patients presenting with malignancy of undefined primary origin (MUO) is challenging, with a lack of validated prognostic tools. Biomarkers of the systemic inflammatory response independently predict survival in other cancer types, but their role in MUO is unclear. The aim of this study was to assess biomarkers of the systemic inflammatory response in patients presenting with MUO. PATIENTS AND METHODS: A biobank of 1049 patients presenting with MUO referred to a regional oncology service in Scotland was analysed. Key inflammatory biomarkers (white cell count, neutrophil count and C-reactive protein combined with albumin [to give the modified Glasgow Prognostic Score {mGPS}]) were examined. The relationship between these and survival was examined using Kaplan-Meier and Cox regression methods. RESULTS: Data were available for 1049 patients. Median survival was 4.3 months (interquartile range: 1.7-16.0 months). On multivariate analysis mGPS was independently associated with survival and stratified survival from 13.6 months (mGPS: 0) to 2.3 months (mGPS: 2) (p < 0.001). The mGPS was predictive of survival on multivariate analysis in patients found to have a non-cancer diagnosis (p = 0.034), an identified primary cancer (0.002), cancer of unknown primary (CUP) (p = 0.011), those for whom biopsy was not done (MUO) (p = 0.036), those found to have an identified primary cancer (0.002) and even those found to have a non-cancer diagnosis (p = 0.034) after further detailed investigations. In patients with CUP mGPS predicted survival regardless of the recognised clinicopathological prognostic subgroup (p < 0.001). CONCLUSIONS: The results of the present study demonstrate that biomarkers of the systemic inflammatory response are reliable prognostic factors in patients presenting with MUO. These simple, objective, routine clinical tests may inform clinical management.

Ovine abortion and stillbirth investigations in Australia.

Fetal loss and lamb mortality between mid-pregnancy and weaning are important economic and welfare issues for the Australian sheep industry. The aim of this study was to determine common causes of ovine abortion and stillbirths based on submissions to veterinary laboratories and identify factors that impact the determination of an aetiological diagnosis. Data for 529 investigations on abortion or stillbirth between 2000 and 2018 were retrieved from four state veterinary laboratories in Western Australia, South Australia, Victoria and Tasmania. An aetiological diagnosis was made for 57% of investigations. Investigations that included placental tissue samples were more than twice as likely to have an aetiological diagnosis compared to investigations without placenta (P = 0.017, 95% confidence interval 1.1, 4.5). Of the investigations where an aetiological diagnosis was made, 81% involved infectious abortion, with Campylobacter spp. (32%), Listeria spp. (25%) and Toxoplasma gondii (9%) being the three most common abortigenic pathogens implicated. The remaining 19% of investigations with an aetiological diagnosis included a wide range of infectious and non-infectious diseases. Diagnoses made varied year to year and between states. No evidence of exotic abortigenic pathogens were reported. Veterinary practitioners can improve the probability of an aetiological diagnosis by emphasising to farmers the importance of collecting any aborted material, especially placenta, and appropriate storage of the tissues until they can be submitted to the laboratory. Some diseases that cause abortion in Australian sheep have zoonotic potential, and veterinary practitioners play an important role in educating clients about appropriate hygiene when handling pregnant and lambing ewes or any aborted material.

Causes of mortality and severe morbidity requiring euthanasia in captive Tasmanian devils (Sarcophilus harrisii) in Tasmania.

BACKGROUND: Devil facial tumour disease (DFTD) is a contagious cancer causing marked population declines in wild Tasmanian devils. In response to this threat, a captive insurance population has been established. This study investigated causes of death in captive Tasmanian devils. METHODS: Clinical and laboratory records of captive Tasmanian devils held in seven Tasmanian captive facilities were analysed for cause of death or severe morbidity requiring euthanasia. RESULTS: Neoplasia was found to be the most common cause of mortality/severe morbidity, accounting for 27/63 of deaths. Cutaneous lymphoma was the most frequently observed tumour (10/27), at a higher incidence than previously reported. The most common cause of severe morbidity, following neoplasia, was leucoencephalomyelopathy, which caused severe, progressive hindlimb paresis and ataxia. CONCLUSION: Neoplasia, specifically cutaneous lymphoma, and degenerative neurological conditions are the most frequent causes of death in captive Tasmanian devils in Tasmania. Further work to determine the aetiologies of these conditions, as well as effective treatments, would be valuable.

Diverse strains of Actinobacillus lignieresii isolated from clinically affected cattle in a geographically restricted area.

OBJECTIVE: To investigate whether an outbreak of Actinobacillus lignieresii was caused by one or multiple strains. METHODS: Nine isolates of A. lignieresii were obtained from the lymph nodes of 15 affected cattle from two farms to determine whether a single strain was involved. An enterobacterial repetitive insertion consensus sequence (ERIC) PCR was used for genotyping, and the repeats-in-toxin genes were analysed by PCR and sequencing. RESULTS: Isolates from the two farms belonged to two and three genotypes, with a total of four genotypes detected. Genes of the apxICABD operons of some strains had deletions in the apxIA (~697 bp) and in the apxID (~187 bp) genes. The toxin gene deletions and the ERIC PCR patterns suggested the involvement of different A. lignieresii genotypes. CONCLUSION: There was no evidence that a unique genotype was associated with actinobacillosis on the two farms, confirming that this disease was associated with other contributing factors.

Ascites due to pre-sinusoidal portal hypertension in dogs: a retrospective analysis of 17 cases.

Accumulation of a pure transudate abdominal effusion in the absence of significant hypoalbuminaemia is uncommon in dogs and is due to pre-sinusoidal portal hypertension. Reported causes of pre-sinusoidal portal hypertension vary, but suggest a reasonable prognosis. A retrospective analysis of 17 dogs that presented to our institution with ascites due to pre-sinusoidal portal hypertension identified idiopathic hepatic fibrosis or canine chronic hepatitis as the underlying cause in the majority of cases. Twelve (70.5%) dogs were 4 years of age or younger at time of presentation. Total serum protein was higher in dogs with chronic hepatitis than it was in dogs without inflammatory disease. The prognosis was generally poor and no histological, imaging or biochemical parameters were useful as prognostic indicators. Dogs died or were euthanased due to severe clinical signs associated with the portal hypertension and/or perceived poor prognosis.

Regionalization: a strategy that will assist with bovine tuberculosis control and facilitate trade.

It is expected that the revised chapter on bovine tuberculosis in the Terrestrial Animal Health Code of the Office Internationale des Epizooties (OIE) will embrace regionalization as a functional means of assisting countries, states or regions to meet the requirements for freedom from tuberculosis and to facilitate trade. The benefits and applications of regionalization, which comprises zoning and compartmentalisation, are discussed. Regionalization requires that a country's veterinary administration is able to implement transparent and auditable biosecurity measures that will ensure that the tuberculosis-free status of a subpopulation of cattle is maintained despite the presence of infection in another cattle subpopulation, or in other domestic or wild animal species. Zoning, which requires cattle subpopulations to be separated by geographic boundaries, provides a practical basis whereby countries, states or regions, can progress towards freedom from tuberculosis, regardless of the source of infection for defined cattle subpopulations. Compartmentalisation however, requires that husbandry or management practices will be used to prevent a tuberculosis-free cattle subpopulation from contacting interspecific and intraspecific sources of infection. This will be difficult to achieve except for specialised cases such as artificial breeding centers.

Retrospective review of laser therapy for palliation of colorectal tumours.

Patients with inoperable colorectal tumours will often require symptomatic relief due to the nature of extensive disease spread or existing co-morbidities. The use of laser treatment for palliation of tumours in the lower gastrointestinal tract has become an attractive treatment option for such patients. This paper presents the results of a retrospective review of 58 case notes in order to determine the effectiveness of laser therapy in palliating symptoms of colorectal tumours. In addition, the paper aims to identify which colorectal symptoms laser is best used to palliate. The study was conducted in a regional coloproctology unit at the Western General Hospital in Edinburgh. The main findings show that 52% (n=30) of patients had successful (complete/good) resolution of symptoms, 36% (n=21) had a poor response and 12% (n=7) had no resolution of symptoms from laser therapy. Of all documented symptoms, this study found that laser is most effective at palliating obstructive symptoms. It also has beneficial application in the palliation of bleeding and mucous discharge. It is less effective for the anal symptoms of tenesmus and pain and for stool related symptoms such as diarrhoea, constipation, frequency and incontinence.

The Edinburgh Malawi Cancer Partnership: helping to establish multidisciplinary cancer care in Blantyre, Malawi.

In response to the growing incidence of cancer in Malawi, a new oncology unit was established at the Queen Elizabeth Central Hospital, Blantyre. The unit opened in 2010, the first in the country, and is led by a single consultant oncologist. In 2012, a healthcare partnership was formed between the oncology and palliative care unit at Queen Elizabeth Central Hospital and the Edinburgh Cancer Centre, UK. The principal objective of the partnership is to help develop high quality multidisciplinary cancer care in Malawi. Methods A needs assessment identified three priority areas for further improvement of cancer services: nurse-led treatment delivery; management of clinical data; and multidisciplinary working. The partnership received grant funding from the Scottish Government Malawi Development Programme in 2013 and a three year project plan was implemented. This has been conducted through a series of reciprocal training visits. Results Key achievements have been completion of a programme of oncology nursing education attended by 32 oncology nurses and other healthcare professionals, which has resulted in increased experience in cancer practice and standardisation of chemotherapy delivery procedures; development of a clinical database that enables prospective collection of data of all new patients with cancer and which links to the Malawi Cancer Registry; development of weekly multidisciplinary meetings involving oncology, gynaecology and surgery that has enabled a cross-specialty approach to patient care. Conclusion The Edinburgh Malawi Cancer Partnership is supporting nursing education, data use and cross-specialty collaboration that we are confident will improve cancer care in Malawi. Future work will focus on the further development of multidisciplinary breast cancer care and the development of a radiotherapy service for patients in Malawi.

The epidemiology of Mycobacterium bovis in wild deer and feral pigs and their roles in the establishment and spread of bovine tuberculosis in New Zealand wildlife.

In New Zealand, wild deer and feral pigs are assumed to be spillover hosts for Mycobacterium bovis, and so are not targeted in efforts aimed at locally eradicating bovine tuberculosis (TB) from possums (Trichosurus vulpecula), the main wildlife host. Here we review the epidemiology of TB in deer and pigs, and assess whether New Zealand's TB management programme could be undermined if these species sometimes achieve maintenance host status. In New Zealand, TB prevalences of up to 47% have been recorded in wild deer sympatric with tuberculous possums. Patterns of lesion distribution, age-specific prevalences and behavioural observations suggest that deer become infected mainly through exposure to dead or moribund possums. TB can progress rapidly in some deer (<10%), but generalised disease is uncommon in wild deer; conversely some infected animals can survive for many years. Deer-to-deer transmission of M. bovis is rare, but transmission from tuberculous deer carcasses to scavengers, including possums, is likely. That creates a small spillback risk that could persist for a decade after transmission of new infection to wild deer has been halted. Tuberculosis prevalence in New Zealand feral pigs can reach 100%. Infections in lymph nodes of the head and alimentary tract predominate, indicating that TB is mostly acquired through scavenging tuberculous carrion, particularly possums. Infection is usually well contained, and transmission between pigs is rare. Large reductions in local possum density result in gradual declines (over 10 years) in TB prevalence among sympatric wild deer, and faster declines in feral pigs. Elimination of TB from possums (and livestock) therefore results in eventual disappearance of TB from feral pigs and wild deer. However, the risk of spillback infection from deer to possums substantially extends the time needed to locally eradicate TB from all wildlife (compared to that which would be required to eradicate disease from possums alone), while dispersal or translocation of pigs (e.g. by hunters) creates a risk of long-distance spread of disease. The high rate at which pigs acquire M. bovis infection from dead possums makes them useful as sentinels for detecting TB in wildlife. It is unlikely that wild deer and feral pigs act as maintenance hosts anywhere in New Zealand, because unrestricted year-round hunting keeps densities low, with far less aggregation than on New Zealand farms. We conclude that active management of wild deer or feral pigs is not required for local TB eradication in New Zealand.

Epidemiology and control of Mycobacterium bovis infection in brushtail possums (Trichosurus vulpecula), the primary wildlife host of bovine tuberculosis in New Zealand.

The introduced Australian brushtail possum (Trichosurus vulpecula) is a maintenance host for bovine tuberculosis (TB) in New Zealand and plays a central role in the TB problem in this country. The TB-possum problem emerged in the late 1960s, and intensive lethal control of possums is now used to reduce densities to low levels over 8 million ha of the country. This review summarises what is currently known about the pathogenesis and epidemiology of TB in possums, and how the disease responds to possum control. TB in possums is a highly lethal disease, with most possums likely to die within 6 months of becoming infected. The mechanisms of transmission between possums remain unclear, but appear to require some form of close contact or proximity. At large geographic scales, TB prevalence in possum populations is usually low (1-5%), but local prevalence can sometimes reach 60%. Intensive, systematic and uniform population control has been highly effective in breaking the TB cycle in possum populations, and where that control has been sustained for many years the prevalence of TB is now zero or near zero. Although some uncertainties remain, local eradication of TB from possums appears to be straightforward, given that TB managers now have the ability to reduce possum numbers to near zero levels and to maintain them at those levels for extended periods where required. We conclude that, although far from complete, the current understanding of TB-possum epidemiology, and the current management strategies and tactics, are sufficient to achieve local, regional, and even national disease eradication from possums in New Zealand.

Detection of parasite peptidase in the plasma of heifers infected with Trypanosoma congolense.

Plasma samples from heifers infected with Trypanosoma congolense were shown to contain a parasite peptidase. In some instances, trypanosome peptidase was detected in plasma samples taken from heifers for up to 14 days after infections had been successfully treated with diminazene aceturate (Berenil). Trypanosome peptidase was detected in plasma using starch gel electrophoresis and also by a dot blot assay in which a McAb, raised against the enzyme, was spotted onto nitrocellulose filters which were then used to absorb enzyme from the samples. The molecular weight of the enzyme was approximately 60,000. The possible role that a trypanosome peptidase may play in inducing pathology and its use in the diagnosis of infection and disease are discussed.

Simultaneous localization and quantification of relative G and F actin content: optimization of fluorescence labeling methods.

Previous studies of fluorescence probes for labeling the monomeric actin pool have demonstrated lack of specificity. We have used quantitative analytical methods to assess the sensitivity and specificity of rhodamine DNAse I as a probe for monomeric (G) actin. The G-actin pool of attached or suspended fibroblasts was stabilized by ice-cold glycerol and MgCl2. Formaldehyde fixation was used to clamp the filamentous (F) actin pool. G- and F-actins were stained by rhodamine DNAse I and FITC-phalloidin, respectively. Confocal microscopy indicated that the G- and F-actins were spatially separate in substrate-attached cells. Flow cytometry and fluorescence spectrophotometry demonstrated low co-labeling of the separate actin pools, although measureable background binding of rhodamine DNAse I was detectable. Estimates of the extent of actin polymerization after trypsinization demonstrated reciprocal changes of monomeric and filamentous actins, consistent with the formation of a perinuclear array of F-actin. The labeling and quantitation methods were also sufficiently sensitive to detect cell type-dependent variations in actin content. Dual labeling of cells with rhodamine DNAse I and FITC-phalloidin may provide a simple and direct method to image and quantify actin rearrangement in individual cells.

A comparison of the isoenzymes of Trypanosoma (Duttonella) vivax isolates from East and West Africa.

The genetic diversity in 13 stocks and clones of Trypanosoma vivax from East and West Africa was compared by isoenzyme analysis. The Ugandan and West African stocks and clones showed a very high degree of genetic similarity to each other but they differed from the Kenyan stocks and clones. Two haemorrhagic stocks, IL 2337 (Galana, Kenya) and IL 3067 (Bamburi, Kenya), showed a high degree of similarity in enzyme banding patterns in electrophoresed preparations. One of the Kenyan stocks, M1D 627, differed in most of its enzyme banding patterns from all the other stocks and clones used.

The pathway study: results of a pilot feasibility study in patients suspected of having lung carcinoma investigated in a conventional chest clinic setting compared to a centralised two-stop pathway.

UNLABELLED: The best chance of cure in non-small cell lung cancer (NSCLC) is surgical resection, but UK rates of 8% compare poorly to 25% in the USA and Europe. Delays in diagnosis in the current UK system may be one reason for such discrepancy. To address this problem we set up a rapid diagnostic system and compared it to the conventional method of investigations in a pilot randomised trial. METHODS: Eighty-eight patients were prospectively enrolled from three District General Hospitals and randomised to either investigation locally or to the rapid system at The Royal Marsden Hospital. The pilot end-points were feasibility and audit of radical treatment rates to enable estimates for patient numbers for the full study. RESULTS: Forty-five and 43 patients were in the central and conventional arms, respectively (65% male, median age 69 years). There was a 4-week improvement in time to first treatment in those in the central arm (P=0.0025) with 13/30 (43%) and 9/27 (33%) patients having radical treatment in the central and conventional arms, respectively. Patients in the conventional arm felt the diagnostic process was too slow (P=0.02) while those in the central arm seemed to have a better care experience (P=0.01). There were significantly less visits to the general practitioner (GP) in the central arm (P=0.02). CONCLUSIONS: This pilot study demonstrates that the full study is feasible but would require the commitment and involvement of a large number of patients and physicians. The results show several advantages to investigations and diagnosis in the central arm, particularly in time to treatment initiation, patient satisfaction and rate of radical treatments. The improved rate of radical treatment could lead to an improved survival rate.

Pneumocystis carinii pneumonitis: a serological study.

Sera from 23 proven or clinically suspected cases of Pneumocystis carinii pneumonitis (PCP) in immunosuppressed patients predominantly with acute lymphoblastic leukaemia, and from 91 normal people, were examined for antibody to P. carinii by indirect immunofluorescence. Low levels of antibody were found in 51 of 91 normal people and elevated or rising titres of antibody in 18 out of 21 cases from whom paired or serial convalescent sera could be obtained.

An antigenic determinant which is variant in a population of Plasmodium falciparum is present in isolates of Plasmodium malariae.

A monoclonal antibody that is directed against an antigenic determinant which is variant in a population of Plasmodium falciparum also reacts with Plasmodium malariae.

Antigenic diversity found in isolates of Plasmodium falciparum from Papua New Guinea by using monoclonal antibodies.

Monoclonal antibodies were used to demonstrate antigenic diversity in over 100 primary isolates of Plasmodium falciparum collected from one area of Papua New Guinea. The frequencies of several parasite antigens in our sample is calculated. One particular antigen which had previously been shown to be absent in one-third of established isolates collected from several countries appeared ubiquitous in our sample from Papua New Guinea. A method is presented that can be used to test for associations between antigens; the analysis also reveals whether other variables affect these associations. Several associations between antigens were revealed. In one instance, the association between two particular parasite antigens was affected by the donor's age. The importance of characterizing the antigenic structure of P. falciparum populations, and its relevance to the introduction of an antimalarial vaccine are discussed.

The relationship between the in vitro response of Plasmodium falciparum to chloroquine, quinine and mefloquine.

We have measured the in vitro response of several isolates of Plasmodium falciparum to chloroquine, quinine and mefloquine. We show that parasites which are resistant to chloroquine also have a reduced sensitivity to quinine. However, there appears to be no correlation between chloroquine resistance and reduced sensitivity to mefloquine. We conclude that the emergence and spread of chloroquine resistance could also be establishing a population of parasites with a reduced sensitivity to quinine which may provide the basis for the eventual emergence of quinine resistance.