Disseminated granulomas associated with nematode larvae in a shortfin mako shark

A shortfin mako shark (Isurus oxyrinchus) caught in 1996 by sportfishermen in Long Island (New York, USA) had many granulomas containing larval nematodes. Granulomas were present in the myocardium, spleen, pancreas, stomach, spiral intestine, hematopoietic tissue within the anterior kidney, and in the branchial septum and primary lamellae of the gills. Epicardial hyperplasia and granulomatous myocarditis were associated with the larvae. Although identification of the larvae was impossible due to lack of distinct morphological features, they resembled dracunculoid larvae previously reported from sharks.

Extracerebral infections of Acanthamoeba spp. in mice. pathomorphological changes in tissues of infected animals

A variety of Acanthamoeba spp. pathogenic strains were isolated from water pools in the area of Poznań. In many cases amoebae invaded lungs, kidney heart, liver and diaphragm causing significant changes in these Organs. The presence of amoeba outside of CNS was found mainly in the early periods of infection. Amoeba isolated from different organs of dead animals did not exhibit any specificity in relation to the organs in following infections. Infection with both low-and high-virulent strains resulted in pathomorphological changes of similar character. However, changes induced by low-virulent parasites developed later and were less extensive.

Acute fulminant sarcocystosis in a captive-born rhesus macaque

A captive-born juvenile female rhesus macaque (Macaca mulatta) was acquired from a commercial breeder and placed in quarantine. Within 8 days of arrival, the animal became anorexic, inactive, and dehydrated. Subsequently, generalized edema and facial ecchymoses developed, and despite supportive therapy, the animal became moribund and was euthanatized. Macroscopic examination showed diffuse stippling and streaking of the myocardium. Histopathologic examination revealed multifocal to coalescing myocardial edema, necrosis, lymphohistiocytic inflammation, and generalized endothelial infection with Sarcocystis sp. Immature and mature schizonts within endothelial cells were most prevalent in the heart. Fewer schizonts were present in the vasculature of other tissues, including skeletal muscle, smooth muscle, adipose tissue, brain, and retina. Mature tissue cysts within muscle fibers were not found in the myocardium but were occasionally seen in skeletal muscle. Analysis of polymerase-chain-reaction-amplified 18s ribosomal RNA gene sequences revealed 96% identity to published sequences of S. hirsuta, S. hominis, and S. fusiformis and 95% identity to S. cruzi and S. tenella. However, sequences did not show complete identity with any organism in the GenBank database. Sequence homology suggests that this is a newly described Sarcocystis sp. Results of antibody tests for simian retrovirus, simian T-lymphotropic virus 1, and simian immunodeficiency virus were negative, suggesting that viral immunosuppression was unlikely to have augmented the pathogenicity of sarcosporidial infection. Clinical and histopathologic findings in this case of fulminant sarcosporidiosis are similar to those described in Dalmeny disease in cattle, which is associated with ingestion of massive numbers of infective Sarcocystis oocysts.

On Brugia (Brugiella subgen. nov.) buckelyi n.sp., from the heart and blood vessels of the Ceylon hare

1. A new species of Brugia (Brugiella subgen. nov.) buckleyi is described from the heart and blood vessels of the Ceylon Hare (Lepus nigricollis singhala).

2. This worm is much larger than the other species of Brugia. It lacks a distinct head bulb and has a relatively much shorter oesophagus. The vulva in the female is close to the posterior extremity of the oesophagus. In the male the caudal papillae differ in their number and arrangement and the spicule ratio is much smaller.

Pathology and morphology of Ichthyophonus hoferi in naturally infected fishes off the Swedish west coast

The pathology and morphology of Ichthyophonus hoferi was studied in naturally infected Atlantic herring Clupea harengus, in sprat Sprattus sprattus, and in flounder Pleuronectes flesus from the west coast of Sweden. The pathogen was found in all organs examined, with the intensity of infection varying in different organs of the different fish species. Two main phases in the life of infecting parasites were identified, 'active' and 'passive', the latter being able to switch to active. The active phase of the infection in herring was usually accompanied by a lean and slender appearance of the body, a drastic decrease in intestinal fat, emaciation of the somatic muscles, swelling of the visceral organs, poor quality of flesh texture and a distinctive off-odour. The most characteristic macroscopic sign of ichthyophonosis in herring and flounder was the occurrence of creamy white nodules on the heart. The infection causes a chronic systemic granulomatous inflammation. The nature of the granulomatous inflammation was host- and tissue-dependent. The pathogenicity of the parasite in its active form and the side effects of host defence cells were also reflected in dramatic tissue damage and loss of structure and function of the infected organs. Three kinds of spores were identified: 'un-developing spore', 'developing spore' and 'plasmodio-spore'. The formation and spread of 'plasmodia', from plasmodio-spores, as a secondary infection agent is documented. Transmission electron microscopy revealed I. hoferi to be multinucleated, containing different organelles and structures. These included a cell wall, an undulating cell membrane, a thin paramural endoplasm, an endoplasmic reticulum, polymorphic but usually spherical mitochondria with short tubulo-vesicular cristae, dictyosomes with plate-like cristernae, large electron-dense lipid droplets and electron-lucid vacuoles, probably containing glycogen.

Structural, ultrastructural studies and evolution of Trypanosoma cruzi-infected mice treated with thioridazine

Thioridazine (THI) is a tricyclic drug that belongs to the phenothiazine series. THI had a lethal effect upon epimastigotes in culture medium in a concentration of 0.5 microM. Trypanocidal effect upon trypomastigotes of Trypanosoma cruzi was observed above 0.5 mM of THI. Ultrastructural studies showed intracellular vacuoles in both parasite forms and mitochondrion reorganization. To analyze the use of THI as a therapy, male mice were inoculated with 7.10(4) trypomastigotes of T. cruzi, Tulahuen strain, and treated with THI for 3 days, with 80 mg/kg/day. Survival and parasitemia of mice treated with lower doses were similar to those observed in the control group (14 days postinfection). THI treatment modified parasitemia levels. They were negative by day 20 p.i. Hearts from control untreated mice presented typical chagasic myocarditis. Hearts from THI-treated mice sacrificed by day 30 p.i. showed inflammatory infiltrates without amastigote nests. Three months postinfection a mild infiltrate located in the interventricular septum was observed. Survival of this group was 9 months. Present results show that THI had a direct effect upon parasitemia, improved survival of treated mice, and modified the evolution of experimental Chagas disease.

Polymerase chain reaction amplification of three different Trypanosoma cruzi DNA sequences from human chagasic cardiac tissue

Chagas' disease is caused by the hemoflagellate protozoan Trypanosoma cruzi. The most common, serious manifestation of Chagas' disease is a progressive inflammatory cardiomyopathy, which occurs decades after primary infection. The inability to consistently demonstrate T. cruzi by histologic techniques in inflammatory cardiac lesions has suggested that the parasites' persistence may not be required for the pathology of the chronic phase. In this report we further analyze the persistence and localization of T. cruzi DNA in the hearts of seven patients with chronic chagasic cardiomyopathy, along with four indeterminate patients and seven control patients seronegative for T. cruzi infection. In the seven patients with chronic chagasic cardiomyopathy, we extracted DNA from selected inflammatory foci-positive (IFP) and inflammatory foci-negative (IFN) areas of' hematoxylin and eosin-stained cardiac tissue. We then used polymerase chain reaction methodology to amplify three different T. cruzi sequences (a minicircle sequence [MCS], a satellite repetitive sequence [RS], and, a low copy number sequence within the gene coding for a flagellar protein [FPS]). The MCS was detected in approximately 100% of both the IFP and IFN areas analyzed. The RS was detected in 37.5% and 23% of the IFP and IFN areas, respectively (difference not statistically significant; P > 0.10, degrees of freedom = 1, G test of independence = 1.9522). The FPS was rarely detected (2%), and was only present in DNA extracted from IFP areas. The MCS was also detected in most indeterminate cases (none of whom had inflammatory lesions) although with a markedly diminished amplification signal relative to cardiomyopathy cases. The MCS was not amplified from the cardiac tissues from seronegative controls. These results suggest that the quantity of T. cruzi DNA persisting in hearts of patients with Chagas' disease correlates with cardiomyopathy, but may not be preferentially associated with inflammatory foci.

Trypanosoma cruzi: detection of a surface antigen cross-reactive to human C-reactive protein

C-reactive protein (CRP) is an acute phase protein secreted by liver hepatocytes, and is also found on the surface of lymphocytes and as a membrane-associated protein expressed on rat liver macrophages and human monocytes. C-reactive protein levels increase in the sera of children infected with Trypanosoma cruzi, during the acute phase of Chagas' disease, but its role in the course of this infection is unknown. Experiments designed to detect the binding of CRP to circulating forms of T. cruzi failed to observe it because anti-human CRP antibodies bind to the parasite. The present work intended to further clarify this novel question related to the anti-CRP cross-reactivity with the parasite. Indirect immunofluorescence, immunoenzymatic, flow cytometry, and Western blot assays showed that three different polyclonal anti-human CRP antibody preparations bind to T. cruzi surface. This binding is dose-dependent, saturable, and is inhibited when anti-CRP antibodies from different species were allowed to compete, indicating the specificity of the reactivity. The antibodies recognized a protein band below 23 kDa in Western blot analysis of parasite extracts. The divalent cation chelators EDTA and EGTA impaired the antigen recognition by the antibodies. The binding to parasite surface was also observed with some available monoclonal antibodies raised against human CRP. A polyclonal anti-human CRP presented an inhibitory effect on invasion of heart muscle cells by T. cruzi. Our results indicate that a molecule antigenically related to CRP, a possible CRP-like molecule, is expressed on the surface of T. cruzi.

Toxoplasma gondii infection in rats by the RH strain: inoculum and age effects

Toxoplasma gondii strains are classified according to their virulence in mice. Rats are considered to be resistant to the infection, depending on the age. Newborn rats are fully susceptible but weaned rats are resistant. However the effect of inoculum has not been examined. Using RH strain inocula of 10(2), 10(4), 5 x 10(7) and 10(8) tachyzoites intraperitoneally inoculated into Wistar and Fischer rats of 7, 11, 21, 24 and 46 days old, the authors show that inoculum and not the age of the host had a statistically significant effect (p < 0.01) on the survival curve.

Toxoplasma gondii: kinetics of the dissemination in the host tissues during the acute phase of infection of mice and rats

Mice and rats differ in their susceptibility to Toxoplasma gondii infection. Here we have compared the parasitological parameters of acute infection in both mice and rats infected either orally with cysts of Prugniaud strain or intraperitoneally (ip) with tachyzoites of the RH strain. The animals were killed at regular interval during the acute phase, and the parasitic burden in mesenteric lymph nodes, spleen, liver, diaphragm, heart, lungs, brain, and blood was assessed by a tissue culture method in MRC5 fibroblast cells. Mice infected with the RH strain showed a drastic increase of the parasitic load in all organs (up to 10 (8) parasites / g of organs), and then died. When mice were infected with 50 cysts of Prugniaud strain, parasites were first observed in mesenteric lymph nodes, spleen, and lungs and then in other organs. In rats, infection with 1200 cysts of the same strain led to a similar pattern; however, the chronology of the infected organs changed when they were infected with RH strain tachyzoites. These results suggest that the parasites, present first in the peritoneal cavity in the case of RH ip infection, infect all the adjacent organs and then the blood which disseminates the tachyzoites all over the organism. In contrast, after an oral infection, the parasite crosses the intestinal barrier to reach the mesenteric lymph nodes and then the spleen and are finally distributed by the blood throughout the organism. We also showed that following infection with a lethal or a sublethal doses of the Prugniaud strain, the parasitic burden in the studied organs was similar and therefore does not directly correlate with the death of the mice.

Myocarditis associated with Theileria spp. in calves

Two 3-week-old Limousin x Retinta calves from extensive farms in the south of Spain died suddenly. Microscopic examination of the spleen and lymph nodes revealed an intense lymphoid proliferation; the germinal centres were prominent and were surrounded by areas of haemorrhage. Parasitic forms, similar to Koch's bodies, were observed in only a small number of lymphoid cells and macrophages. In the myocardium a severe myocarditis was found. Inflammatory cells were in close contact with damaged myocytes, sometimes surrounding fragments of cells. In some areas the vessels had intraluminal deposits of fibrin. The endothelial damage and thrombosis may have contributed to the damage observed in the myocytes, together with the cytotoxic mechanism associated with the presence of an intense inflammatory infiltrate. The active multiplication of parasites may be due to the age of the animals and their breed, since they are not an autochthonous breed and present low resistance to infection.

Prevalence of Toxoplasma gondii in Canadian market-age pigs

During 1991 and 1992, 2,800 market-age pigs were sampled at federally inspected abattoirs from across Canada. Anti-Toxoplasma gondii IgG at titers of > or =1:32 were found in 240 pigs examined by a commercial, latex agglutination test. Seroprevalences ranged from 3.5 to 13.2% in the different regions of the country. Tissue hybridization studies using a previously developed probe demonstrated T. gondii ribosomal RNA in 9 of 36 animals, whereas mouse bioassay testing of heart muscle and diaphragm from all 2,800 pigs failed to demonstrate the presence of infective stages of T. gondii in tissues. Although serology results from this study indicated that Canadian market-age pigs are infected with T. gondii at rates similar to those reported from other parts of North America, mouse bioassay results suggested that Canadian pork products contain low levels of infective organisms. This apparent discrepancy suggests that serological evidence of T. gondii infection in pigs alone does not accurately assess the public health risks associated with consuming improperly cooked pork products.

Sarcocystis-associated encephalitis and myocarditis in a wild turkey (Meleagris gallopavo)

A Sarcocystis-like organism was associated with encephalitis and myocarditis in an ataxic, emaciated adult male turkey (Meleagris gallopavo) from Gilmer County, West Virginia. Protozoal schizonts and merozoites were associated with areas of inflammation and occasionally necrosis in both the heart and the brain. The organisms divided by endopolygeny and stained positively with anti-Sarcocystis cruzi serum in an immunohistochemical test.

Trypanosoma cruzi infection in tumor necrosis factor receptor p55-deficient mice

Tumor necrosis factor receptor p55 (TNFRp55) mediates host resistance to several pathogens by allowing microbicidal activities of phagocytes. In the studies reported here, TNFRp55-/- mice infected with the intracellular parasite Trypanosoma cruzi showed clearly higher parasitemia and cumulative mortality than wild-type (WT) controls did. However, gamma interferon (IFN-gamma)-activated macrophages from TNFRp55-/- mice produced control levels of nitric oxide and killed the parasite efficiently in vitro. Trypanocidal mechanisms of nonphagocytic cells (myocardial fibroblasts) from both TNFRp55-/- and WT mice were also activated by IFN-gamma in a dose-dependent way. However, IFN-gamma-activated TNFRp55-/- nonphagocytes showed less effective killing of T. cruzi than WT control nonphagocytes, even when interleukin 1beta (IL-1beta) was added as a costimulator. In vivo, T. cruzi-infected TNFRp55-/- mice and WT mice released similar levels of NO and showed similar levels of IFN-gamma mRNA and inducible nitric oxide synthase mRNA in their tissues. Instead, increased susceptibility to T. cruzi of TNFRp55-/- mice was associated with reduced levels of parasite-specific immunoglobulin G (IgG) (but not IgM) antibodies during infection, which is probably linked to abnormal B-cell differentiation in secondary lymphoid tissues of the mutant mice. Surprisingly, T. cruzi-infected TNFRp55-/- mice showed increased inflammatory and necrotic lesions in several tissues, especially in skeletal muscles, indicating that TNFRp55 plays an important role in controlling the inflammatory process. Accordingly, levels of Mn2+ superoxide dismutase mRNA, a TNF-induced enzyme which protects the cell from the toxic effects of superoxide, were lower in mutant than in WT infected mice.

Microsporidia of the genus Trachipleistophora--causative agents of human microsporidiosis: description of Trachipleistophora anthropophthera n. sp. (Protozoa: Microsporidia)

Trachipleistophora anthropophthera n. sp., was found at autopsy in the brain of one and in the brain, kidneys, pancreas, thyroid, parathyroid, heart, liver, spleen, lymph nodes, and bone marrow of a second patient with AIDS. The parasite is similar to the recently described T. hominis Hollister, Canning, Weidner, Field, Kench and Marriott, 1996, in having isolated nuclei, meronts with a thick layer of electron dense material on the outer face of their plasmalemma and sporogony during which spores are formed inside a thick-walled sporophorous vesicle. In contrast to T. hominis, this species is dimorphic as it forms two kinds of sporophorous vesicles and spores: Type I--round to oval polysporous sporophorous vesicle, 7-10 microns in size, usually with eight spores (3.7 x 2.0 microns), thick endospores, subterminal anchoring disc and anisofilar polar filaments forming seven thicker and two thinner terminal coils. This type of sporophorous vesicle is associated with 25-30 nm filaments extending into the host cell cytoplasm. Type II--smaller, bisporous sporophorous vesicle (4-5 x 2.2-2.5 microns) with two, nearly round, thin-walled spores, 2.2-2.5 x 1.8-2.0 microns in size, having 4-5 isofilar coils. No outside filamentous elements are associated with the bisporous sporophorous vesicle. Both types of sporophorous vesicles were common in the infected brain tissue and could be found within the same cell. The newly described species, together with T. hominis and previously reported Pleistophora-like parasites from human muscle, likely represent a group of closely related human microsporidia.

Hapalotrema (Digenea: Spirorchidae) in the green turtle (Chelonia mydas) in Australia

Hapalotrema mehrai Rao, 1976 and Hapalotrema postorchis Rao, 1976 (Digenea: Spirorchidae) are redescribed from the heart and pulmonary arteries of the green turtle, Chelonia mydas, from Moreton Bay in south-eastern Queensland. Hapalotrema pambanensis Gupta and Mehrotra, 1981 from C. mydas in India is made a synonym of H. mehrai. Hapalotrema dorsopora Dailey, Fast and Balazs, 1993 from C. mydas from Hawaii was described with a dorsally opening uterine pore, but this is found to be the opening of Laurer's canal; therefore H. dorsopora is also made a synonym of H. mehrai. In addition to differences in the numbers of testes and general dimensions, H. mehrai and H. postorchis differ in the development of Laurer's canal and in the absence of a canalicular seminal receptacle in H. postorchis.

Increasing prevalence of canine heartworm in coyotes from California

Thirty-seven subadult and adult coyotes (Canis latrans), collected August 1992 through December 1996 from a coastal foothill area in northern California (USA), were examined for adult heartworm (Dirofilaria immitis). During 1992 through 1993, at the end of a 6 yr drought, none of four coyotes examined were infected with heartworms. However, during 1994 through 1996, after the drought had ended, prevalences were 91% in 23 adult coyotes and 40% in 10 subadult coyotes. Heartworm intensity did not differ by sex of coyote, and averaged (+/- SE) 19.4 +/- 3.8 among adults; one subadult had > 238 heartworms. The prevalence and intensity of heartworm infection in coyotes reported here for 1994 through 1996 are the highest reported anywhere in the United States.

Species of Myxobolus (Myxozoa) from the bulbus arteriosus of centrarchid fishes in North America, with a description of two new species

Three species of Myxobolus (Myxozoa, Myxosporea) occur in heart tissue of centrarchids. Myxobolus paralintoni Li and Desser, 1985 from Lepomis gibbosus in Algonquin Park and in Lake Erie, Ontario, has subcircular spores (in plane of spore length) in frontal view (11-13 microm long, 9-10 microm wide, and 5 microm thick) with a width-to-length ratio of 1:1.2. Myxobolus jollimorei n. sp. from Lepomis macrochirus in Lake Erie and in the Pascagoula River System, Mississippi, has subcircular spores (in plane of spore width) in frontal view (10.0-11.5 microm long, 12.0-14.5 microm wide, and 6.5-8.0 microm thick) with a width-to-length ratio of 1:0.8. Myxobolus manueli n. sp. from Pomoxis nigromaculatus in Lake Erie has spores (10-11 microm long, 8-10 microm wide, and 6.5-7.0 microm thick) that are nearly circular in frontal view but that have 2 distinct sublateral knobs along the sutural ridge and a width-to-length ratio of 1:1.2. All 3 species occur in the bulbus arteriosus of their hosts where they form small, saucer-shaped pseudocysts. Free spores were found free in the lumen of the heart and bulbus arteriosus, in bile, and in kidney tissue presses.

Relationships between histopathological findings and phylogenetic divergence in Trypanosoma cruzi

Problems have been raised by natural genetic diversity of Trypanosoma cruzi, the causal agent of Chagas' disease, and other protozoa in terms of both basic and applied science. T. cruzi manifests a great diversity of medical and biological properties which could be the origin of clinical variability in the disease. We propose possible correlations between genetic distances, or phylogenetic divergence, and histopathological data. To ascertain this aspect, 15 cloned stocks pertaining to three major clones or genotypes (19, 20 and 39) were compared. Sets of 24 mice infected with each stock were studied for histopathological lesions. Brain, heart, lung, liver, spleen, urinary bladder, bone marrow, colon, kidney and skeletal muscle were extracted from each mouse. Qualitative and quantitative differences showed at histopathological examination. An important encephalic softening was found in brains of most mice infected by genotype 20, corresponding to areas of inflammation and liquified necrosis. Other inflammatory tissue lesions in the histological sections of the three genotypes were similar. Skeletal muscle tropism was higher than cardiac tropism in all the studied genotypes. All three genotypes shared parasite presence in skeletal muscle. Differences related to cardiac tropism were important: in genotype 19, 50% of studied stocks presented pseudocysts; 20% in genotype 20 and 83% in genotype 39. Parasite presence in other tissues was scanty: in brain only in genotype 20 and in spleen and liver only in genotype 39. We found important histopathogenicity differences among the three studied genotypes, but they do not support the hypothesis of zymodeme pathogenic specificity due to the great diversity among stocks within each genotype.

The development and persistence of phanerozoites in experimental infections of Plasmodium sasai

Phanerozoites of Plasmodium sasai parasitised virtually all tissues of Takydromus tachydromoides infected by inoculation of blood, and persisted until each lizard died, 2-296 days postinoculation. At 4 days postinoculation, phanerozoites were larger than at 2 and 6 days; many were observed rupturing, suggesing a maturation time of approximately 4 days. The proliferation of phanerozoites decreased after 2 months postinoculation, but small phanerozoites were still present at 296 days. A few encysted phanerozoites (chronozoites) appeared at 2 days postinoculation, but from 75 days comprised over half of parasites present in most tissues. Some differences in mean size and shape were evident among various organs. Phanerozoites occurred in connective tissue and endothelium in all organs, but were most plentiful in the heart in every infection, often occurring in clusters of > 30 schizonts, with up to 105 found in single sections at 4 days. Phanerozoites did not parasitise reticular cells of the spleen and bone marrow, in contrast to Plasmodium mexicanum as described in unnatural host species. Little difference was seen between two strains of P. sasai in its natural host T. tachydromoides and a strain isolated from Takydromus smaragdinus.

Sarcocystis suihominis detected for the first time from pigs in Japan

Sarcoystis suihominis was detected for the first time in Japan from the heart and diaphragm of 5 out 600 older culled breeding pigs slaughtered in Saitama Prefecture, Japan. Fresh cysts were 1,080-2,040 x 106-170 microns in size. Bradysoites measured 15 x 4 microns on average. The cyst wall was usually observed thick, 4-6 microns, and striated, but occasionally thin and smooth according to the difference in sectioning angle and in portion of cysts. Scanning electron microscopy showed that many palisade-like villar protrusions, 6-6 x 0.3-0.5 microns in size, were closely folded onto the surface of cyst. A small number of microtubules were seen in the core of protrusion. No dogs nor domestic cats fed with 20 fresh cysts each excreted oocysts or sporocysts in the feces throughout the experimental period of 30 days.

Enhanced prevalence of T cells expressing TCRBV8S2 and TCRBV8S3 in hearts of chronically Trypanosoma cruzi-infected mice

We have analysed the relative T cell receptor (TCR) BV gene usage in T cells from hearts and spleens of CBA/HJ mice chronically infected with the Tulahuén strain of Trypanosoma cruzi. During chronic infection, CBA/HJ mice recruit T cells at the major site of inflammation (i.e. the heart), with over-representation of certain TCRBV gene subfamilies (TCRBV8S2 and TCRBV8S3). In contrast, no signal or a very weak message from a limited number of T cells was recorded from one heart of the control group. No alteration of TCRBV distribution was recorded in spleens of chronically infected CBA/HJ. Our findings indicate that there is a preferential TCRBV gene usage in the T cell response in the hearts of chronically infected mice. Furthermore, the pattern of CDR3 lengths in inflammatory T cells was altered.

Sarcocystosis in capercaillie (Tetrao urogallus) in Finland: description of the parasite and lesions

Acute generalized sarcocystosis was diagnosed in a capercaillie (Tetrao urogallus) from Finland. Microscopic lesions were seen in the heart, lungs, spleen, liver, and brain. Protozoa were found in all organs, especially in the lungs and spleen. Only asexual stages were observed. The parasite divided by endopolygeny. Schizonts were usually 10 microm wide and up to 55 microm long. Merozoites are 3-4 microm long and 1.5-2.0 microm wide. Sarcocysts and sexual stages are unknown. The parasite was considered to be a species of Sarcocystis with an unknown life cycle. This is the first report of acute sarcocystosis in capercaillie from Finland.

Neosporosis-associated bovine abortion in Pennsylvania

Neospora caninum was found in fetal tissues of 34 of 688 cases of bovine abortion submitted to the Pennsylvania Animal Diagnostic Laboratory System during the period from May 1994 to November 1996. The aborted fetuses ranged in gestational age from 3 to 8 months. Microscopic lesions consisted primarily of encephalitis and myocarditis. A labeled (strept) avidin-biotin staining procedure using anti-N. caninum polyclonal rabbit serum revealed N. caninum organisms within the fetal brain (27 of 27), heart (10 of 13), placenta (5 of 6), kidney (2 of 2), liver (1 of 4) and skeletal muscle (1 of 1).

Lesions caused by cardiovascular flukes (Digenea: Spirorchidae) in stranded green turtles (Chelonia mydas)

Evidence of infection with spirorchid flukes (Digenea: Spirorchidae) was sought at necropsy of 96 stranded green turtles, Chelonia mydas, that were examined during the course of a survey of marine turtle mortality in southeastern Queensland, Australia. Three species of spirorchid (Hapalotrema mehrai, H. postorchis, and Neospirorchis schistosomatoides) were identified. Severe disease due to spirorchid fluke infection (spirorchidiasis) was implicated as the principal cause of mortality in 10 turtles (10%), and appeared to be one of multiple severe problems in an additional 29 turtles (30%). Although flukes were observed in only 45% of stranded C. mydas in this study, presumed spirorchid fluke infection was diagnosed in an additional 53% of turtles, based principally on characteristic necropsy lesions and to a lesser extent on the histopathological detection of spirorchid eggs. Characteristic necropsy lesions included miliary spirorchid egg granulomas, which were observed most readily on serosal surfaces, particularly of the small intestine. Cardiovascular lesions included mural endocarditis, arteritis, and thrombosis, frequently accompanied by aneurysm formation. Resolution of thrombi was observed to occur via a combination of granuloma formation about indigestible components (spirorchid fluke egg shells) and exteriorization through the vessel wall, which resulted in granulomatous nodules on the adventitial surface. Septic aortic thrombosis complicated by disseminated bacterial infection, observed in five turtles, was recorded for the first time. Egg granulomas were ubiquitous in turtle tissues throughout this study. Although they generally appeared to be mild or incidental lesions, they were occasionally associated with severe multifocal granulomatous pneumonia or meningitis.