Experimental Reptarenavirus Infection of Boa constrictor and Python regius.

Boid inclusion body disease (BIBD) causes losses in captive snake populations globally. BIBD is associated with the formation of cytoplasmic inclusion bodies (IBs), which mainly comprise reptarenavirus nucleoprotein (NP). In 2017, BIBD was reproduced by cardiac injection of boas and pythons with reptarenaviruses, thus demonstrating a causative link between reptarenavirus infection and the disease. Here, we report experimental infections of Python regius (n = 16) and Boa constrictor (n = 16) with three reptarenavirus isolates. First, we used pythons (n = 8) to test two virus delivery routes: intraperitoneal injection and tracheal instillation. Viral RNAs but no IBs were detected in brains and lungs at 2 weeks postinoculation. Next, we inoculated pythons (n = 8) via the trachea. During the 4 months following infection, snakes showed transient central nervous system (CNS) signs but lacked detectable IBs at the time of euthanasia. One of the snakes developed severe CNS signs; we succeeded in reisolating the virus from the brain of this individual and could demonstrate viral antigen in neurons. In a third attempt, we tested cohousing, vaccination, and sequential infection with multiple reptarenavirus isolates on boas (n = 16). At 10 months postinoculation, all but one snake tested positive for viral RNA in lung, brain, and/or blood, but none exhibited the characteristic IBs. Three of the four vaccinated snakes seemed to sustain challenge with the same reptarenavirus; however, neither of the two snakes rechallenged with different reptarenaviruses remained uninfected. Comparison of the antibody responses in experimentally versus naturally reptarenavirus-infected animals indicated differences in the responses.IMPORTANCE In the present study, we experimentally infected pythons and boas with reptarenavirus via either intraperitoneal injection or tracheal instillation. The aims were to experimentally induce boid inclusion body disease (BIBD) and to develop an animal model for studying disease transmission and pathogenesis. Both virus delivery routes resulted in infection, and infection via the trachea could reflect the natural route of infection. In the experimentally infected snakes, we did not find evidence of inclusion body (IB) formation, characteristic of BIBD, in pythons or boas. Most of the boas (11/12) remained reptarenavirus infected after 10 months, which suggests that they developed a persistent infection that could eventually have led to BIBD. We demonstrated that vaccination using recombinant protein or an inactivated virus preparation prevented infection by a homologous virus in three of four snakes. Comparison of the antibody responses of experimentally and naturally reptarenavirus-infected snakes revealed differences that merit further studies.

Encephalitozoon cuniculi infection in Barbary striped grass mice (Lemniscomys barbarus).

INTRODUCTION: Encephalitozoon cuniculi is an obligate intracellular microsporidian parasite that commonly induces subclinical infections in rabbits, but occurs also in a range of other species, including various rodents, carnivores, humans and birds. The present report describes encephalitozoonosis in a group of captive Barbary striped grass mice (Lemniscomys barbarus) in a zoo collection. The aetiology was confirmed by immunohistochemistry and PCR with subsequent sequencing. The source of infection is not known.

Arenavirus Coinfections Are Common in Snakes with Boid Inclusion Body Disease.

Recently, novel arenaviruses were found in snakes with boid inclusion body disease (BIBD); these form the new genus Reptarenavirus within the family Arenaviridae. We used next-generation sequencing and de novo sequence assembly to investigate reptarenavirus isolates from our previous study. Four of the six isolates and all of the samples from snakes with BIBD contained at least two reptarenavirus species. The viruses sequenced comprise four novel reptarenavirus species and a representative of a new arenavirus genus.

Blunt Force Trauma in Veterinary Forensic Pathology.

Veterinary pathologists commonly encounter lesions of blunt trauma. The development of lesions is affected by the object's mass, velocity, size, shape, and angle of impact and by the plasticity and mobility of the impacted organ. Scrape, impact, and pattern abrasions cause localized epidermal loss and sometimes broken hairs and implanted foreign material. Contusions are best identified after reflecting the skin, and must be differentiated from coagulopathies and livor mortis. Lacerations-traumatic tissue tears-may have irregular margins, bridging by more resilient tissue, deviation of the wound tail, crushed hairs, and unilateral abrasion. Hanging or choking can cause circumferential cervical abrasions, contusions and rupture of hairs, hyoid bone fractures, and congestion of the head. Other special forms of blunt trauma include fractured nails, pressure sores, and dog bites. Ocular blunt trauma causes extraocular and intraocular hemorrhages, proptosis, or retinal detachment. The thoracic viscera are relatively protected from blunt trauma but may develop hemorrhages in intercostal muscles, rib fractures, pulmonary or cardiac contusions or lacerations with subsequent hemothorax, pneumothorax, or cardiac arrhythmia. The abdominal wall is resilient and moveable, yet the liver and spleen are susceptible to traumatic laceration or rupture. Whereas extravasation of blood can occur after death, evidence of vital injury includes leukocyte infiltration, erythrophagocytosis, hemosiderin, reparative lesions of fibroblast proliferation, myocyte regeneration in muscle, and callus formation in bone. Understanding these processes aids in the diagnosis of blunt force trauma including estimation of the age of resulting injuries.

Mycobacterium microti tuberculosis in its maintenance host, the field vole (Microtus agrestis): characterization of the disease and possible routes of transmission.

The field vole (Microtus agrestis) is a known maintenance host of Mycobacterium microti. Previous studies have shown that infected animals develop tuberculosis. However, the disease is also known in cats and is sporadically reported from humans and other mammalian species. We examined trapped field voles from an endemic area, using a range of diagnostic approaches. These confirmed that a combination of gross and histological examination with culture is most appropriate to identify the true prevalence of the disease, which was shown to be more than 13% at times when older animals that have previously been shown to be more likely to develop the disease dominate the population. The thorough pathological examination of diseased animals showed that voles generally develop systemic disease with most frequent involvement of spleen and liver, followed by skin, lymph nodes, and lungs. The morphology of the lesions was consistent with active disease, and their distribution suggested skin wounds or oral and/or aerogenic infection as the main portal of entry. The demonstration of mycobacteria in open skin lesions, airways, and salivary glands indicated bacterial shedding from the skin and with sputum and saliva. This suggests not only the environment but also direct contact and devouring as likely sources of infection.

Effect of different blood-guided conditioning programmes on skeletal muscle ultrastructure and histochemistry of sport horses.

The effects of three different blood-guided conditioning programmes on ultrastructural and histochemical features of the gluteus medius muscle of 2-year-old sport horses were examined. Six non-trained Haflinger horses performed three consecutive conditioning programmes of varying lactate-guided intensities [velocities eliciting blood lactate concentrations of 1.5 (v1.5 ), 2.5 (v2.5 ) and 4 (v4 ) mm respectively] and durations (25 and 45 min). Each conditioning programme lasted 6 weeks and was followed by a 5-week resting period. Pre-, post- and deconditioning muscle biopsies were analysed. Although training and detraining adaptations were similar in nature, they varied significantly in magnitude among the three different conditioning programmes. Overall, the adaptations consisted in significant increases in size of mitochondria and myofibrils, as well as a hypertrophy of myofibrillar ATPase type IIA muscle fibres and a reduction in number of type IIx low-oxidative fibres. Together, these changes are compatible with a significant improvement in both muscle aerobic capacity and muscle strength. The use of v1.5 and v2.5 as the exercise intensities for 45 min elicited more significant adaptations in muscle, whereas conditioning horses at v4 for 25 min evoked minimal changes. Most of these muscular adaptations returned towards the pre-conditioning status after 5 weeks of inactivity. It is concluded that exercises of low or moderate intensities (in the range between v1.5 and v2.5 ) and long duration (45 min) are more effective for improving muscle features associated with stamina and power in sport horses than exercises of higher intensity (equivalent to v4 ) and shorter duration (25 min).

Cyclosporine induced generalized hyperkeratosis in a dog.

INTRODUCTION: Cyclosporine is a potent immunosuppressive agent used in veterinary medicine to treat a variety of inflammatory or immune mediated conditions. Many adverse effects are associated with this medication, however most of them rarely occur. A 5-year-old, female intact French bulldog was presented with multiple, multifocally distributed, severe hyperkeratotic and papillomatous/verrucous plaques. The dog was on long-term immunosuppressive treatment with cyclosporine for meningoencephalitis of unknown origin (MUO). It had an history of atopic dermatitis and calcinosis cutis. A papillomavirus infection was excluded by polymerase chain reaction (PCR), and histopathologic analysis revealed a chronic lymphoplasmacytic non-specific dermatitis, perifolliculitis and periadnexitis and focal folliculitis with papillomatous epidermal hyperplasia and orthokeratotic hyperkeratosis. The diagnosis of "cyclosporine-induced epidermal hyperplasia with secondary pyoderma" was made. Cyclosporine was discontinued and as an alternative mycophenolate mofetil was started to control the MUO. An antimicrobial treatment was prescribed for three weeks. After four months, the skin lesions had healed completely. To date after 2 years, the dog is still in remission. The occurrence of hyperplastic lesions associated with cyclosporine therapy have already been described in previous reports. Most of them resemble those of psoriasiform lichenoid dermatitis, although papilloma virus may be detected in some instances. The dog of the present case showed some peculiarities in the histopathological findings, and a papillomavirus involvement was ruled out with PCR. Like observed in a previous report, there was no correlation between cyclosporine blood level and the severity of dermatological changes. A discontinuation of cyclosporine resulted in complete healing in 4 months. This case highlights the importance of regular monitoring and follow-ups in patients on immunosuppressive therapy. Even rare side effects should always be considered in these cases.

INTRODUCTION: La cyclosporine est un puissant agent immunosuppresseur utilisé en médecine vétérinaire pour traiter une variété de conditions inflammatoires ou à médiation immunitaire. De nombreux effets indésirables sont associés à ce médicament, mais la plupart d'entre eux se produisent rarement. Un bouledogue français intact, âgé de 5 ans, a été présenté avec de multiples plaques hyperkératosiques et papillomateuses/verruqueuses sévères, réparties de manière multifocale. Le chien suivait un traitement immunosuppresseur à long terme à base de cyclosporine pour une méningo-encéphalite d'origine inconnue (MUO). Il avait des antécédents de dermatite atopique et de calcinosis cutis. Une infection à papillomavirus a été exclue par réaction en chaîne par polymérase (PCR) et l'analyse histopathologique a révélé une dermatite chronique lymphoplasmocytaire non spécifique, une périfolliculite et une périannexite ainsi qu'une folliculite focale avec hyperplasie épidermique papillomateuse et hyperkératose orthokératosique. Le diagnostic d'¼hyperplasie épidermique induite par la cyclosporine avec pyodermie secondaire¼ a été posé. La cyclosporine a été stoppée et on a commencé à administrer du mycophénolate mofétil comme alternative pour contrôler l'OMU. Un traitement antimicrobien a été prescrit pendant trois semaines. Après quatre mois, les lésions cutanées étaient complètement guéries. À ce jour, après deux ans, le chien est toujours en rémission. L'apparition de lésions hyperplasiques associées au traitement par la cyclosporine a déjà été décrite dans des rapports précédents. La plupart d'entre elles ressemblent à celles de la dermatite lichénoïde psoriasiforme, bien que le virus du papillome puisse être détecté dans certains cas. Le chien du cas présent présentait quelques particularités dans les résultats histopathologiques et une implication du papillomavirus a été exclue par PCR. Comme observé dans un rapport précédent, il n'y avait pas de corrélation entre le taux sanguin de cyclosporine et la sévérité des altérations dermatologiques. L'arrêt de la cyclosporine a permis une guérison complète en 4 mois. Ce cas souligne l'importance d'une surveillance et d'un suivi réguliers des patients sous traitement immunosuppresseur. Les effets secondaires, même rares, doivent toujours être pris en compte dans ces cas.

Haematology, biochemistry and morphological features of peripheral blood cells in captive Boa constrictor.

The common boa (Boa constrictor) belongs to the family Boidae and represents one of the most popular traded and kept snake species in captivity. The early diagnosis, prevention and prophylaxis of diseases in this species, and in reptiles in general, still pose major challenges, also due to the lack of reliable reference values. This prompted us to conduct a study on clinically healthy captive B. constrictor to assess their basic health parameters in the blood (haematological and biochemical values, stress markers). Several parameters differed significantly between younger (<3 years) and older (≥3 years) boas; in the latter, the percentages of eosinophils, the haemoglobin and haematocrit levels, as well as the albumin and total protein levels, were higher. In male snakes, cholesterol levels were significantly higher than in females. Light and electron microscopy as well as immunohistochemistry served to identify and determine the morphological features of peripheral blood cells, that is, heterophils, basophils, eosinophils, azurophils, monocytes, lymphocytes, thrombocytes and erythrocytes. Leukocyte subpopulations, that is, T and B cells and monocytes, were also identified based on specific marker expression. The study provides data on haematological, biochemical and stress hormone levels, suitable as reference values, and on the blood cell morphology of B. constrictor which can serve as a guideline for further research on this species.

Inconspicuous post-mortem findings in rabbits from Switzerland naturally -infected with Rabbit Haemorrhagic -Disease Virus 2.

INTRODUCTION: Rabbit Haemorrhagic Disease Virus 2 (RHDV-2) emerged in France in 2010. In Switzerland, RHDV-2 was first identified in 2015 and apparently has almost replaced the classical Rabbit Haemorrhagic Disease Virus (RHDV) by now. Like RHDV, RHDV-2 causes a viral hepatitis with a peracute course and an increased mortality rate within the rabbitry. RHDV infection causes consistent gross pathological findings, especially in the liver and respiratory tract. Reports about gross pathology for animals naturally infected with RHDV-2 is scarce. The present study analysed the anamnesis and necropsy reports of 35 rabbits examined during routine diagnostics between March 2015 and May 2017. A reverse transcriptase real-time polymerase chain reaction (RT-qPCR) specific for RHDV-2 and RHDV proved a total of 25 animals to be positive for RHDV-2, while none was positive for RHDV. Additionally, histological examinations were performed on liver, lung, and kidney of 18 rabbits that had tested positive by RHDV-2 RT-qPCR. The anamnestic report more often stated an increased mortality rate in RHDV-2 positive (16/18, 89 %) compared to RHDV-2 negative rabbits (3/9, 33 %). Gross pathology did not reveal any pathognomonic changes in RHDV-2 positive animals. Histologically, the liver showed the most severe lesions followed by lung and kidney. Animals positive for RHDV-2 frequently showed signs of gastro-intestinal disease (n = 5) and/or septicaemia (n = 6) masking possible indicators of an RHDV-2 infection, such as the rather unspecific findings of an enlarged spleen or an enlarged, friable, tan-coloured liver. The authors want to raise awareness among clinicians and pathologists that in case of sudden death in commercial or pet rabbits, RHDV-2 needs to be considered as differential diagnosis and should be confirmed by laboratory diagnosis.

INTRODUCTION: Le virus 2 de la maladie hémorragique du lapin (RHDV-2) est apparu en France en 2010. En Suisse, le RHDV-2 a été identifié pour la première fois en 2015 et semble avoir presque remplacé le virus classique de la maladie hémorragique du lapin (RHDV). Comme le RHDV, le RHDV-2 provoque une hépatite virale avec une évolution suraiguë et un taux de mortalité élevé chez les lapins. L'infection par le RHDV entraîne des constatations pathologiques bruts cohérents, notamment au niveau du foie et des voies respiratoires. Les rapports sur la pathologie macroscopique des animaux naturellement infectés par le RHDV-2 sont rares. La présente étude a analysé les rapports d'anamnèse et de nécropsie de 35 lapins examinés lors de diagnostics de routine entre mars 2015 et mai 2017. Une réaction en chaîne par polymérase en temps réel à la transcriptase inverse (RT-qPCR) spécifique pour le RHDV-2 et le RHDV a prouvé qu'un total de 25 animaux étaient positifs pour le RHDV-2, tandis qu'aucun n'était positif pour le RHDV. De plus, des examens histologiques ont été réalisés sur le foie, les poumons et les reins de 18 lapins qui avaient été testés positifs par RT-qPCR pour le RHDV-2. Le rapport anamnestique faisait plus souvent état d'un taux de mortalité accru chez les lapins RHDV-2 positifs (16/18, 89 %) que chez les lapins RHDV-2 négatifs (3/9, 33 %). La pathologie macroscopique n'a révélé aucun changement pathognomonique chez les animaux RHDV-2 positifs. Sur le plan histologique, le foie présentait les lésions les plus graves, suivi des poumons et des reins. Les animaux positifs pour le RHDV-2 présentaient fréquemment des signes de maladie gastro-intestinale (n = 5) et/ou de septicémie (n = 6) masquant les indicateurs possibles d'une infection par le RHDV-2, tels que les découvertes plutôt peu spécifiques d'une rate hypertrophiée ou d'un foie hypertrophié, friable et de couleur beige. Les auteurs souhaitent sensibiliser les cliniciens et les pathologistes au fait qu'en cas de mort subite chez des lapins d'élevage ou de compagnie, le RHDV-2 doit être considéré comme un diagnostic différentiel et doit être confirmé par un diagnostic de laboratoire.

Are bi-axial proximal sesamoid bone fractures in the British Thoroughbred racehorse a bone fatigue related fracture? A histological study.

OBJECTIVES: To investigate whether microfractures and alterations in the trabecular bone area are associated with catastrophic bi-axial proximal sesamoid bone fractures (PSBF). METHODS: Proximal sesamoid bones (PSB) from 10 racehorses with PSBF and from 10 control racehorses without musculoskeletal injury were examined using the bulk basic fuchsin method. Bone histomorphometric and microfracture analysis was performed, and cases and controls compared using two-sample t-test, paired t-test, and Mann-Whitney U test. RESULTS: There was no significant difference in the microfracture density and the trabecular bone area between bones from case and control horses, and between fractured and non-fractured bones in case horses. CLINICAL RELEVANCE: Microfracture density was low in the areas of the PSB examined. Microfracture density was not significantly different between groups, indicating that propagation of micro-cracks is an unlikely predisposing pathologic alteration in PSBF in British racehorses. There was no significant difference in the bone surface area between groups, which one would expect if modelling, adaptation and an increase in bone density were associated with PSBF fracture in the case horses. Therefore, PSBF in the British racehorse does not appear to be associated with microfractures of the trabecular bone of the PSB. The PSB fractures might represent an acute monotonic fracture; however, the aetiology of the fractures remains unknown with additional research required.

European Forensic Veterinary Pathology Comes of Age.

During the mid-1700s, development of the veterinary profession was largely focussed on equine medicine and surgery. Subsequently, rather erratic development encompassed other species and eventually led to specialization in different disciplines. Teaching of veterinary pathology was well established in Europe and North America by the late 19th century. Specialization in this discipline was boosted in the 1940s by the formation, in the USA, of the Register of Veterinary Pathology and American College of Veterinary Pathologists. National societies followed soon afterwards in Europe. The European Society of Veterinary Pathology evolved during this period and the European College of Veterinary Pathologists (ECVP) was created in 1995 to promote high standards in the discipline. As an accrediting body, its emphasis is on training and harmonization across Europe. There is an increasing demand for high-grade forensic veterinary pathology reports which address the requirements of the legal system, but so far only a few countries have defined protocols for these reports. In recognition of the need for a specific qualification that benchmarks the competences and experience expected of forensic veterinary pathologists, the ECVP recently launched the Certificate in Forensic Veterinary Pathology.

Mycobacterium pinnipedii: transmission from South American sea lion (Otaria byronia) to Bactrian camel (Camelus bactrianus bactrianus) and Malayan tapirs (Tapirus indicus).

Tuberculosis infections caused by Mycobacterium (M.) pinnipedii in a South American sea lion, Bactrian camel, and Malayan tapirs kept in two zoological gardens spanning a time period of 5 years are reported. The zoos were linked by the transfer of one tapir. Conventional bacteriological and molecular methods were applied to detect the pathogen. Spoligotyping and MIRU/VNTR-typing performed to assess the genetic similarity revealed identical molecular characteristics of the isolates from all animals involved. Anti-tuberculosis antibodies were detected using ELISA and a recently developed serological rapid test. The study shows that: (i) using molecular methods, the assessment of the genetic relationship of infectious agents helps to confirm the routes of infection, and that (ii) immunological tests may help to detect tuberculosis infections ante mortem more reliably and early. This would prevent the transfer of tuberculosis by asymptomatic animals.

Microanatomy of the digestive tract, hooves and some visceral organs of addax antelope (Addax nasomaculatus) following a concentrate or forage feeding regime.

Subacute ruminal acidosis is a common disease in captive non-domesticated ruminants and is mainly diagnosed by rumen fluid pH and rumen histology. Furthermore, differences in ruminant gastrointestinal histology have been hypothesized to correlate with the browser-grazer continuum. Twelve surplus addax antelope (Addax nasomaculatus) were divided into two groups, fed either their usual diet, consisting of a concentrate feed with a limited amount of hay, or a diet of unlimited hay only, for 3 months. After culling, descriptive and morphometric histology and pH measurements were compared between groups. Significant variations in cellular subpopulations were noted between groups, with roughage-fed individuals presenting primarily with balloon cells of the Stratum corneum and living layer cell vacuolization, whereas parakeratosis and intermediate-type cells were more frequent in the concentrate-fed group. Lesions typical of subacute ruminal acidosis were significantly more pronounced in concentrate-fed individuals. Ruminal pH measurements did not differ significantly, but were more consistent in forage-fed individuals, indicating a more stable reticuloruminal environment. The results indicate that ruminal histology may be more appropriate in assessing ruminal health compared to a single post-mortem pH measurement. It is proposed that Stratum corneum balloon cells may indicate cell maturation and not, as previously assumed, hyperfunction. Concentrate-fed individuals scored higher on the presence of inflammatory cells on hoof corium histology. The study further emphasizes the adaptability of ruminant digestive tract microanatomy in adult animals even after a short period of time and the positive effects an increased roughage diet may have in populations of captive grazing ruminants.

The intraspecies diversity of C. albicans triggers qualitatively and temporally distinct host responses that determine the balance between commensalism and pathogenicity.

The host immune status is critical for preventing opportunistic infections with Candida albicans. Whether the natural fungal diversity that exists between C. albicans isolates also influences disease development remains unclear. Here, we used an experimental model of oral infection to probe the host response to diverse C. albicans isolates in vivo and found dramatic differences in their ability to persist in the oral mucosa, which inversely correlated with the degree and kinetics of immune activation in the host. Strikingly, the requirement of interleukin (IL)-17 signaling for fungal control was conserved between isolates, including isolates with delayed induction of IL-17. This underscores the relevance of IL-17 immunity in mucosal defense against C. albicans. In contrast, the accumulation of neutrophils and induction of inflammation in the infected tissue was strictly strain dependent. The dichotomy of the inflammatory neutrophil response was linked to the capacity of fungal strains to cause cellular damage and release of alarmins from the epithelium. The epithelium thus translates differences in the fungus into qualitatively distinct host responses. Altogether, this study provides a comprehensive understanding of the antifungal response in the oral mucosa and demonstrates the relevance of evaluating intraspecies differences for the outcome of fungal-host interactions in vivo.

Gongylonema pulchrum infection and esophageal squamous cell carcinoma in a vari (Lemur macaco variegata; Kehr 1792).

This report describes the morphologic and histologic features of a case of esophageal Gongylonema pulchrum infection and esophageal squamous cell carcinoma in a 17-yr-old, female vari (Lemur macaco variegates). The lemur had lived in a German zoo and had a clinical history of dyspnea, vomiting, and anorexia. At necropsy, a whitish, soft, nodular, centrally necrotic mass was found in the caudal third of the esophagus. In addition, numerous intraepithelial nematodes (G. pulchrum) were observed in the entire esophagus. Results suggest a relation between infection with G. pulchrum and development of an esophageal squamous cell carcinoma.

Zoonotic helminths of urban brown rats (Rattus norvegicus) in the UK: neglected public health considerations?

Urban brown rats (Rattus norvegicus) carry microbial human pathogens but their role as reservoir hosts for helminths of public health importance is less well known. In this study, 42 brown rats trapped on Merseyside were subject to thorough combined helminthological and pathohistological post-mortem examination. Eggs of the rodent-borne zoonotic nematode Calodium hepaticum were initially detected in histological sections of the livers of 9.5% of rats, but overall diagnostic sensitivity increased to 16.6% when entire liver tissue was disrupted and the resulting filtrates were examined for released eggs. In their rat host, mainly trapped inside the dockland, infections with C. hepaticum were associated with a chronic multifocal pyogranulomatous hepatitis with intralesional eggs and peripheral fibrosis. Mean intensity of hepatic C. hepaticum egg infections was 1041 eggs. This is the first report of C. hepaticum in an urban brown rat population in the UK and provides original data for liver egg burdens in this abundant commensal rodent. The zoonotic cestode Rodentolepis nana had a prevalence of infection of 14.3%. Rodent-specific, non-zoonotic helminths found were the spiruroid Mastophorus muris (16.0%) in the stomach, the trichuroid Trichosomoides crassicauda in the urinary bladder (31.0%); the ascarid Heterakis spumosa was the commonest helminth of the large intestine (76.2%). Many millions of brown rats inhabit cities and rural areas of the UK, and the infective stages of the zoonotic worm species, particularly C. hepaticum, are likely to be widely distributed in the environment presenting a threat to public health.

Septicaemia in emerald monitors (Varanus prasinus Schlegel 1839) caused by Streptococcus agalactiae acquired from mice.

The present study was performed to investigate both the identity and the source of the bacteria responsible for a fatal septicaemia observed in a group of three subadult emerald monitors (Varanus prasinus Schlegel 1839). The emerald monitors were necropsied and examined by light microscopy, including immunohistology, and by electron microscopy. Tissue samples were additionally submitted for bacteriological, virological and parasitological examinations. The virological and parasitological results were noncontributory, whereas the bacteriological investigation resulted in the isolation of gram-positive cocci which were characterized biochemically and serologically and by molecular analysis. The death of the emerald monitors was caused by a partially leukocyte-associated septicaemic infection with streptococci of serological group B of serotype V. Phenotypically and genotypically identical group B streptococci were isolated from the intestine of subadult mice, obtained from the feed used for the monitors. The genotypical characterization included an identical DNA fingerprint of strains of both origins, indicating the epidemiological relation between the feeding mice and the infections of the monitors.

Cytokine mRNA levels in isolated feline monocytes.

Real-time PCR systems were developed to quantitate cytokine expression in short-time cultivated feline monocytes. Feline-specific interleukin-1beta (IL-1beta), IL-6, and tumor necrosis factor-alpha (TNF-alpha) primers as well as TaqMan probes were designed and were adapted to a quantitative PCR system which had been previously established for feline IL-10 and IL-12 p40. Quantitative analysis of cytokine messenger RNA (mRNA) transcription based on the comparison of the cytokine with the housekeeping gene feline glyceraldehyde-3-phosphate dehydrogenase (GAPDH), providing universally expressed mRNA. GAPDH mRNA was readily detectable in cDNA prepared from short-time cultivated peripheral blood monocytes. Cytokine mRNA was demonstrated in all samples at variable amounts. IL-1beta and TNF-alpha mRNA was constitutively expressed whereas IL-6, IL-10 and IL-12 p40 mRNA was generally expressed at a lower level and was occasionally not detected. There was a great variability of cytokine production between individual cats and at different time points in the same cat.

A study of sequential histopathology of Trypanoplasma borreli (Protozoa: Kinetoplastida) in susceptible common carp Cyprinus carpio.

The tissue response of common carp Cyprinus carpio to the kinetoplastid blood parasite Trypanoplasma borreli Laveran & Mesnil, 1901 was investigated during a laboratory infection of a highly susceptible carp line. With the development of the parasitaemia an increased proliferation of the lymphoid renal interstitial tissue was induced, which resulted in a progressive depression and deterioration of renal tubules. In heavily infected carp at Days 20 to 28 post inoculation (PI), a tubulonephrosis, a glomerulitis caused by a massive accumulation of leukocytes in glomerular capillaries, and large numbers of trypanoplasms in blood vessels and renal interstitium were observed. Corresponding with rising T. borreli numbers in the peripheral blood, splenic lymphocytes showed increasing proliferation rates, and the capillaries of the liver, gills, heart and intestine were infiltrated with lymphocytes and trypanoplasms. In heavily infected carp, congestion of liver sinusoids, focal necroses of hepatic tissue, extensive accumulations of erythrocytes in the spleen and in the blood marked anaemia were observed. These carp often showed abdominal distension, exophthalmus and swimming disorders described as 'sleeping sickness of carp'. Proliferation of cells from the interstitial lymphoid tissue of the kidney, which bears a close resemblance to the bone marrow of higher vertebrates, is considered a normal immune response of fish to antigen challenge. We here describe the unique case of a severe but ineffective immune reaction which results in the destruction of excretory renal structures. This has to be considered a severe disturbance of osmoregulation in affected carp, which, together with a decrease in oxygen uptake due to anaemia, is likely a major cause of death in these carp.

Cytopathological observations on renal tubule epithelium cells in common carp Cyprinus carpio under Trypanoplasma borreli (Protozoa: Kinetoplastida) infection.

Cytological alterations in renal tubule epithelium cells of carp Cyprinus carpio infected with the blood flagellate Trypanoplasma borreli Laveran & Mesnil, 1901 were investigated during the course of a laboratory infection of a highly susceptible carp line. With the development of the parasitaemia, a hyperplasia of the interstitial renal tissue was induced, which resulted in a tubulus necrosis. Cytological changes were already seen in tubulus epithelium cells on Day 7 post injection (PI) of the parasite. The basilar invaginations of the cells fragmented and a swelling of mitochondria was noted. With increasing parasitaemia, on Days 14 and 21 PI, these changes progressed up to the loss of the basilar invagination and high amplitude swellings of mitochondria and deterioration of their internal membrane structures. Cells of the distal tubule segment reacted earlier and more rapidly than cells of the proximal tubule. The cytological alterations suggested a loss of function of the epithelum cells, which most likely resulted in impaired ionic and osmotic regulation of T. borreli-infected fishes. Our findings indicate that in response to the proliferation of the interstitial renal tissue cell structures of the renal tubule cells are altered quickly and in a progressive manner.