Sarcocystis sp. from cattle slaughtered in Japan

Sarcocystis sp. was detected from cattle slaughtered in Saitama Prefecture, Japan. The cysts were 3,400-4,400 x 198-238 microm in size and had the thick cyst wall which was 7 to 10 microm thick and provided with finger-like villar protrusions. The protrusions were 8-9.5 x 2-2.5 microm in size and had microtubules in the core.     

Ultrastructural differentiation between sarcocysts of Sarcocystis hirsuta and Sarcocystis hominis

The ultrastructure of macroscopic (2-7 mm) Sarcocystis hirsuta sarcocysts from naturally infected cattle from New Zealand was compared with the ultrastructure of 222-day-old S. hominis in experimentally infected cattle in the United States. The villar protrusions of S. hirsuta were approximately 8 microns long, constricted at the base, expanded laterally in the mid-region and tapered distally. Some of the villar tips were folded to form two to four conical projections. The distal portion of the villar protrusions was bent at an angle of 45-90 degrees to the sarcocyst surface. The villar core contained numerous microfilaments and rows of electron-dense granules. The villar protrusions of S. hominis were cylindrical, oriented nearly perpendicularly to the sarcocyst surface, not constricted at their base and contained relatively few electron-dense granules. Although the sarcocysts of S. hirsuta were indistinguishable from those of S. hominis by light microscopy, they were distinguishable ultrastructurally.     

First case report of Sarcocystis neurona-induced equine protozoal myeloencephalitis in Japan

Equine protozoal myeloencephalitis developed in a three-year-old male Thoroughbred racehorse imported from the United States. The animal showed astasia five days after the onset of ataxia. Histopathologically, focal nonpurulent myelitis accompanied by hemorrhage and perivascular infiltration was observed in the fourth and fifth cervical spinal cord. Immunohistochemically, shizonts were occasionally observed and were positive for anti-Sarcocystis neurona (S. neurona) antiserum. S. neurona-specific antibodies were detected in the serum and cerebrospinal fluid by Western blot. This is the first equine protozoal myeloencephalitis case in Japan.     

First isolation of Sarcocystis neurona from the South American opossum, Didelphis albiventris, from Brazil

Sarcocystis neurona was isolated from sporocysts from two of eight South American opossums, Didelphis albiventris, from Brazil. Interferon gamma gene knock out (KO) mice fed sporocysts from two opossums developed neurologic sarcocystosis. S. neurona was demonstrated in the brains of infected KO mice by immunohistochemical staining with anti-S. neurona antibody. The parasite was cultivated in cell culture and S. neurona DNA was isolated from cultured merozoites. This is the first report of isolation of S. neurona from Brazil and the first report from its new host, D. albiventris.     

Prevalence of Sarcocystis spp. in Argentinean cattle

Sarcocystis cruzi, S. hirsuta and S. hominis are apicomplexan parasites that affect cattle worldwide with variable prevalence. The aim of the present study was to evaluate the prevalence of Sarcocystis spp. in Argentinean cattle comparing microscopic fresh examination and molecular methods. Blood, myocardium and loin samples were collected in five slaughterhouses from a total of 380 bovines. Origin of animals was representative of the major beef cattle production area of Argentina. Samples were analyzed by fresh microscopical examination, transmission electron microscopy (TEM), IFAT and PCR-RFLP. Thin walled sarcocysts corresponding with S. cruzi were found in 99.5% of heart samples. Sarcocysts were detected in 73.1% of loin samples; 71.5% had S. cruzi cysts and 23.1% had thick walled sarcocysts (S. hirsuta or S. hominis). TEM observation revealed the presence of characteristic S. hominis and S. hirsuta cyst walls in 7 and 1 loin samples respectively. Using IFAT, 379/380 animals had titers 25 or higher, showing a full agreement with fresh examination. Amplification products were detected in 35.5% (135/380) of loin samples; however Sarcocystis species could only be determined by RFLP in 29 samples. Agreement between fresh examination and PCR was low (Kappa value=0.262). This is the first report of S. hominis and S. hirsuta in Argentina. Further studies are needed to improve the sensitivity of molecular methods for species identification, especially for differentiation of S. cruzi and S. hirsuta from the zoonotic species S. hominis. The results of the present study and others focusing on sensitivity and specificity of Sarcocystis spp. diagnostic methods should contribute to improve food safety.     

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.     

First in vitro isolation of Besnoitia besnoiti from chronically infected cattle in Germany

Besnoitia besnoiti was in vitro isolated during the first recorded outbreak of bovine besnoitiosis in Germany. Molecular characterization of the new isolate, named Bb-GER1, revealed almost 100% identity with other B. besnoiti isolates obtained in Portugal, Spain, Israel or South Africa, when partial sequences of the 18S ribosomal RNA gene, of the internal transcribed spacer 1 and of the 5.8S RNA gene were compared. Cystozoites obtained from skin tissue of one bull were infectious for γ-interferon knockout (GKO) mice by intraperitoneal (ip) inoculation. Tachyzoites were detected in the peritoneal cavity, spleen, liver and lung of the mice 5 days post-infection. The parasite could be maintained in GKO mice by ip inoculation for at least 5 passages. Peritoneal washings containing tachyzoites were obtained from infected mice and used to infect five cell lines (Vero, MARC-145, NA42/13, BHK₂₁, KH-R). The best growth of tachyzoites was observed in BHK₂₁ cells, but replication occurred to a smaller extent also in MARC-145, NA42/13 and KH-R cells. Subsequent comparative analyses revealed that after direct infection of these cell lines with cystozoites derived from bovine skin, the growth was best in NA42/13 cells. Considerable replication was also observed in the BHK₂₁ and KH-R cell lines. Our observations on the growth characteristics of Bb-GER1 partially contrast those for other isolates. The preferential growth in particular cell lines may be characteristic for particular B. besnoiti isolates. A potential association between growth properties and differences in virulence remains to be established. This is the first in vitro isolation of B. besnoiti from cattle in Germany.     

Efficacy of ivermectin against Dermatobia hominis in cattle

Dermatobia hominis, the tropical warble fly, is one of the most important ectoparasites of cattle in Latin America. The results of five trials conducted in Paraguay, Brazil and Colombia showed that ivermectin administered subcutaneously at a dose level of 200 mcg/kg body weight was highly effective against the three larval stages of D. hominis in cattle.     

Reovirus isolation from healthy dogs in Japan

Twenty-two strains of viruses isolated from apparently healthy dogs were identified as reoviruses on the basis of their biological, physico-chemical and morphological properties. The cross hemagglutination-inhibition test revealed that all of them were of type 1, except one which was of type 3. The significance of reovirus isolation from healthy animals is discussed.     

Staphylococcus aureus variety hominis in a cattle herd

A site-linked hominis variety of Staphylococcus aureus was isolated from a cattle herd. The find coincided with accumulated occurrence of clinical mastitis in cows and the affliction of one milker with a nose furuncle. The origin of the strain was not elucidated. The same strain had been isolated throughout three years of observation from clinical and subclinical mastitis as well as from chronic udder affection of cows, but no extraordinary accumulation of clinically manifest mastitis had been observed. The hominis site variety was quite rare among Staphylococcus aureus strains isolated from other cow herds. Enterotoxin formation was recorded from strains of the hominis site variety and from strains which could not be coordinated with any other of the known site varieties and fell under crystal-violet Type A. No enterotoxin formation was recordable from the strains of the bovis variety. The same applied to the group of staphylococci of crystal-violet Type C which could not be coordinated either with any known site variety and which is assumed to have originated from the hominis site variety. The above findings do not support any conclusion as to whether the cows had been infected by the milker or vice versa.     

Differential molecular identification of Taeniid spp. and Sarcocystis spp. cysts isolated from infected pigs and cattle

In the present work, the species-specific identification of Taeniid spp. cysticerci and sarcocystis cysts isolated from infected pigs and cattle was achieved by PCR. In particular: (i) multiplex-PCR derived from HDP2 DNA fragment, specific for Taenia saginata/Taenia solium; (ii) PCRs and PCR-RFLPs of the rDNA internal transcribed spacers 1 and 2 (ITS1 and ITS2) for the differential diagnosis of taeniids; (iii) PCR derived from the 18S rRNA gene and sequencing, specific for Sarcoystis spp. The combined application of these three PCR protocols provided an unequivocally specific diagnosis of T. saginata, T. solium, T. hydatigena, Sarcocystis hominis and Sarcocystis suihominis, and may have practical application in the identification of calcified degenerating or morphologically dubious cysts, for example in the slaughter house situation or in human biopsy samples.     

First isolation of Histophilus somni from goats

Histophilus somni (former name: Haemophilus somnus) is a Gram-negative, facultative pathogen bacterium that colonises the mucous membranes of cattle and sheep, however it was also described in American bison and bighorn sheep. It can cause local or generalised diseases and asymptomatic carriers can also occur. The presence and the etiological role of this microorganism have not been confirmed in any other domesticated species yet. The purpose of this study was to prove the presence of H. somni in goats by bacterial isolation. Nasal, vaginal or praeputial swab samples were collected from 205 goats in 10 flocks. H. somni strains were isolated from 2 out of 10 flocks; in one flock 10 H. somni strains were isolated from the genital mucosa of 17 goats, while a single H. somni strain was cultured from a vagina of 26 animals in the other flock. Partial amplification and sequencing of the 16S rRNA gene of three H. somni strains verified the identification. The comparative examination of carbon source metabolism using the Biolog Microstation ID System (Biolog, Ca) showed a close relationship of the caprine strains, while they were less related to H. somni type strain CCUG-36157 of bovine origin. H. somni strains were isolated only in the oestrus season from goat flocks with sheep contact. This is the first paper on isolation of H. somni from goats.