Besnoitia in a palaearctic lizard (Lacerta dugesii) from Madeira

Besnoitia cysts in the heart of a lizard (Lacerta dugesii) from the islands of Madeira are the first record of besnoitiosis in a poikilothermic animal in the Old World. The size of the cysts corresponds to those found in lizard genera (Basiliscus and Ameiva) from Panama which belong to B. darlingi. Up to now nothing is known concerning the life cycle of this species from Madeira but it seems possible that cats function as definitive hosts as well as in the other species.

Sarcocystis infection and myocardial pathological changes in cattle from south-eastern Norway

The incidence of myocardial sarcocystis infection and of myocardial pathological changes was recorded in samples of 79 healthy cattle obtained from an abattoir. The incidence rate of thin-walled cysts of S. cruzi was 81.0 %, while mixed infection with thick-walled cysts of S. hominis and/or S. hirsuta was found in 5.0 %. Focal interstitial myocarditis was found in 31.6 % of the samples. The sarcocystis infection and the interstitial mononuclear cell infiltrates were positively associated (P < 0.05). Intimai proliferations of musculo-elastic or fibro-elastic tissues in the intramural coronary arteries were found in 75.0 % of the cattle older than 3% years of age, and in 45.7 % of the cattle less than 3½ years old. No association of the arterial lesions and the sarcocystis infection was demonstrated.

[Distribution of extra-hepatic schistosomiasis lesions in mice infected by BH and SJ strains of Schistosoma mansoni]

Foi estudada a distribuição dos granulomas esquistossomóticos no baço, pulmões, rins, coração e intestinos de camundongos parasitados pelas linhagens BH e SJ de S. mansoni. Verificou-se que a distribuição de granulomas produzidos pelos esquistossomos das duas linhagens é semelhante, sendo que a linhagem BH produziu número significativamente maior de lesões no baço e nos pulmões.

Sarcocystis in man: a review and report of five cases

Sarcocystis was identified in biopsy specimens of skeletal muscle from two adults in Singapore and one in Bombay, and in muscle obtained at autopsy from an adult in Uganda, and in the heart of a child in Costa Rica. Review of case reports revealed that in seven reported cases, including three reported by Lindemann, non-parasite objects were misinterpreted as sarcocysts; in four instances organisms of undetermined classification were described, and in 35 cases true sarcocysts were observed. Among the sarcocysts seen in the 40 cases (35 old, 5 new), seven morphological types were recognized, each representing one to several different species, all of which are zoonotic and none of which can be designated Sarcocystis lindemanni. Among the four types of sarcocysts found in skeletal muscle, three closely resembled a corresponding species found commonly in monkeys: one from a man in Uganda corresponding to a species in Ceropithicus talapoin, forms from India resembling one or two species in Macaca mulatta, and forms from Southeast Asia resembling a species in Macaca fascicularis. Among three types of sarcocysts found in the human heart, one resembled a species commonly seen in the heart of cattle. Of the 40 Sarcocystis infections in man, 13 probably were acquired in Southeast Asia, 8 in India, 5 in Central or South America, 4 each in Africa and Europe, 3 in USA, 1 IN China and 2 in unknown localities. Associated conditions include muscle soreness or weakness in 7 cases, subcutaneous swellings in 5, eosinophilia in 2, and periarteritis or polyarteritis nodosa in 2 cases. However, evidence of pathogenicity of the mature sarcocyst is inconclusive.

An investigation of the route and progression of Encephalitozoon cuniculi infection in adult rabbits

Rabbits infected either orally or intratracheally with cell culture-grown Encephalitozoon cuniculi were monitored regularly for serum antibody levels and E. cuniculi in the urine. Their responses were compared with intravenously inoculated and uninoculated control rabbits. All rabbits receiving E. cuniculi developed serum antibodies, generally within 3 weeks, and excreted E. cuniculi by 6 weeks. In the acute stage of infection, the organs most affected were lung, kidney and liver; the brain and gut were unaffected. However, during chronic infection, the brain, kidney, and heart were the only organs found to be involved. Antibody levels were very high at this stage. Thus both the oral and tracheal routes may be normal routes of infection with E. cuniculi in adult rabbits.

Sarcocystis in free-ranging herbivores on the National Bison Range

Heart, esophagus, diaphragm and skeletal muscle obtained from various herbivores on the National Bison Range were examined grossly for Sarcocystis. Sarcocystis was found in 81, 50, 50, and 13% of the mule deer, (Odocoileus hemionus), white-tailed deer (O. virginianus), elk (Cervus elaphus), and bison (Bison bison), respectively.

[Experimental studies on the affinity of Toxoplasma gondii to various organs of mice (author's transl)]

In response to their alleged "uterus affinity" the organotropism of various Toxoplasma strains was investigated in the female mouse. Using quantitative histological (immunofluorescence) and serological (Sabin-Feldman-dye test, complement fixation test), we examined the brain, heart, lung, spleen, striated muscle, uterus and ovaries. The following results were obtained: All four of the Toxoplasma strains (ALT, DX, WEISS, GAIL) showed a definite neurotropism. Located in the brain were one hundred times as many cysts as in the sexual organs and ten times as many as in the reamining organs. The uterus and ovary show a low susceptibility, invasion rarely occuring. An "uterus affinity" could not be confirmed. All four Toxoplasma strains showed the same affinity for the various organs. The strain ALT showed the most virulence and formed the most cysts.

Tissue tropism of different Trypanosoma cruzi strains

A systematic study of the distribution of intracellular parasites in the organs and tissues was performed in groups of mice inoculated with 4 different Trypanosoma cruzi strains. An extremely high parasitism of spleen, liver, and bone marrow was observed in mice inoculated with Y and Berenice strains; with CL strain, however, parasites were almost absent in those organs. Bloodstream forms apparently present differences which facilitate or prevent their uptake by macrophages from the mononuclear phagocytic system. Parasitism of the smooth muscle from hollow organs was significantly higher with ABC and Berenice strains than with Y and CL. The importance of the distribution of intracellular stages in the pathogenesis of the disease is discussed.

[Toxoplasmosis-induced myocarditis]

The clinical picture of myocarditis was studied in 72 patients with toxoplasmic infection and in 44 patients not suffering from this infection. Comparison of the clinical signs of myocarditis in these two groups showed that myocarditis of toxoplasmic etiology has no characteristic features. The only distinction between these two groups was the different frequency of various symptoms. In view of this, methods of laboratory diagnosis of toxoplasmosis acquire much significance.

[Characteristics of toxoplasmosis-induced myocarditis in experimental peroral infection]

In oral infection with cysts and oocysts of strain 131 Toxoplasma gondii, specific interstitial productive myocarditis with involvement of the endo- and pericardium developed in albino mice and guinea pigs in the acute stage of the process. Toxoplasmic myocarditis terminated in focal cardiosclerosis. The intensity of cardiac affection was higher in oral infection with toxoplasm oocysts than in infection with cysts than in infection with cysts. Unabating persistence of toxoplasms in the myocardium of the infected animals after subsidence of acute inflammatory phenomena was revealed (cysts in the myocardium).

Naturally occurring hepatozoonosis in a coyote

Schizonts of Hepatozoon sp. were found in the myocardium of an adult cyote (Canis latrans) collected from the Aransas National Wildlife Refuge, Austwell, Texas. This constitutes the first time hepatozoonosis has been recorded in Canidae in the Western Hemisphere.

Fine structure of immature cysts of Sarcocystis cruzi

Sarcocystis cruzi forms cysts in striated muscle of the bovine host following schizogony. The fine structure of the immature cyst within muscle fibers of the ventricular myocardium was studied in relation to its development and to the multiplication of parasites within it. The young cyst is enclosed by a cyst wall containing numerous small protuberances. Metrocytes within the cyst are irregular in shape and are separated from each other and the cyst wall by a thin layer of ground substance. The parasite multiplies by endodyogeny within the metrocyte. As the cyst enlarges, the host muscle fiber is disrupted and large protrusions are present in the cyst wall.

[Ultrastructure of the cyst wall of sarcocysts of the roe deer (Capreolus capreolus L.) (author's transl)]

The ultrastructure of the cyst wall of two types of sarcocysts from roe deer is described. In the thin-walled cyst (wall thickness 0.18-00.26 micrometer), the primary cyst wall forms long, finger-shaped protrusions distant from one another and running in parallel with the surface of the cyst (Figs. 1a--d, FP). No fibrils are observable in the protrusions. The primary cyst wall between them forms numerous bubble-like invaginations (Fig. 1c, arrows). In the thick-walled cysts (wall thickness 4.9--7.49 micrometer), the primary cyst wall forms massive, palisade-like protrusions lying close one to another (Figs. 2a, c). There are numerous fibrillar and tubular structures in these protrusions (Fig. 2d), and the primary cyst wall occasionally forms shallow invaginations at the base of some protrusions (Fig. 2b). The unit membrane onthe surface of some protrusions is slightly undulated and covered with a layer of short and thick bars on the outside. The sarcocysts found in roe deer are compared with those from cattle and sheep.

Dirofilaria immitis: experimental infections in the ferret (Mustela putorius furo)

The ferret, Mustela putorius furo, was found to be susceptible to Dirofilaria immitis infection when exposed to low (14) or high (280-420) numbers of infective larvae harvested from Aedes aegypti. Eight ferrets (half of them cortisonized) were inoculated subcutaneously with 14 larvae each. All of them were subsequently found to harbor D. immitis in the heart, and all but one of them had worms of both sexes. Six of these ferrets were examined for microfilaremia at 31 to 35 weeks after inoculation; 3 were positive (one observed only at postmortem examination) and there was evidence that fertilization of female worms had occurred in one other. Females up to 25.5 cm and males up to 16.0 cm were recovered. There was no evidence that the cortisonization of some ferrets had affected the infections. Both male and female ferrets became infected. Four cortisonized ferrets were inoculated with 280 or 420 larvae of D. immitis (divided equally between subcutaneous and intraperitoneal routes). All of them died 16 to 18 weeks after inoculation, yielding 102 to 125 immature D. immitis. In these lethal infections, worms were recovered from the heart and adjoining vessels, and also from vascular and extravascular sites throughout the body.

Increased susceptibility to infection with Brugia pahangi in aged female jirds (Meriones unguiculatus)

Female Mongolian jirds, Meriones unguiculatus, from 5 age groups of 2, 12, 16, 21, and 28 months, were infected with Brugia pahangi. Infections were followed for 125 days by weekly bleedings beginning 55 days postinoculation. Jirds were then killed and adult parasites recovered. Results showed a significant shortening of the prepatent period in the 12-, 21-, and 28-month-old groups. The proportion of gravid female worms did not vary significantly among the 5 groups. Similarly, the ratio of females to male worms showed little variation from group to group. Microfilaremia data for the 5 infection groups show an age-associated increase in numbers of circulating microfilariae. Some individuals in the 28-month group demonstrated 1,500 to 3,000 microfilariae per 0.25 ml peripheral blood, a level that was not approached by young females.