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PubMed2026

Canine cholecystitis in the presence of Hammondia spp. infection.

Biliary protozoal infections are becoming increasingly recognized in dogs. Sarcocystidae protozoal infections (i.e Toxoplasma, Neospora, Hammondia, Besnoitia, and Sarcocystis spp.) are uncommon and host-specific. Diagnosis is traditionally dependent on tissue or serologic evaluation; sensitivity and specificity for these techniques can vary. PCR amplification and genetic sequencing provide a technique to expedite diagnosis and species identification in clinical biliary protozoal infections. Bile samples were collected percutaneously from two dogs presented to a referral hospital with mixed hepatopathies and hyperbilirubinemia. Diagnostic imaging revealed changes consistent with hepatobiliary inflammation, and tachyzoites were identified via bile cytology. Sera were positive for anti-Toxoplasma sp. (n = 1/2) and anti-Neospora sp. (n = 2/2) antibodies. Genomic isolation from bile and pan-Sarcocystidae (18S rRNA) PCR amplification were consistent with Hammondia spp. Additional 28S rRNA (LSU), alpha-tubulin (aTUB) and cytochrome b (CytB) gene-specific fragments were PCR amplified and sequenced. Phylogenetic analysis of LSU DNA fragment (584 bp) suggested both patients were infected with Hammondia spp. closely related to H. heydorni. Sequencing of aTUB (234 bp) and CytB (344 bp) revealed Patient 1 Hammondia spp. was more closely related to H. triffittae, while Patient 2 was more similar to H. heydorni. Treatment with clindamycin, and in one case additional enrofloxacin, resolved clinical and clinicopathologic changes in both dogs. This report highlights the importance of multilocus sequencing in protozoal identification in atypical infections, clinical manifestations of canine hepatobiliary hammondiasis, and need for regional Sarcocystidae prevalence studies.

Animals↗
PubMed1978

[Comparative review of the developmental biology of the genera Sarcocystis, Frenkelia, Isospora, Cystoisospora, Hammondia, Toxoplasma and Besnoitia (author's transl)].

A review is given of the advances in our knowledge of the developmental biology of the so-called cyst-forming coccidia in the years from 1974 to 1978. Until 1970 only 6 Isospora species were known to occur in cats, dogs and men. After the discovery of the coccidian nature of the genera Toxoplasma, Sarcocystis, Besnoitia and Frenkelia, and after the discovery of the new genus Hammondia the number of known species rose to over 30. In addition it could be shown that also birds of prey, owls and reptiles serve as final hosts for several Sarcocystis and Frenkelia species. The coccidia with isosporoid oocysts can be classified into two major groups: Species with gamogony and sporogony in the final host (Sarcocystis, Frenkelia) and species with schizogony and gamogony in the final host and sporogony on the ground (Isospora, Cystoisospora, Hammondia, Toxoplasma, Besnoitia). The subdivision of the first group into the genera Sarcocystis and Frenkelia based on the localization of their cysts in the musculature and in the brain, respectively, cannot be upheld in the future. Their classification into organisms with small cystozoites of about 7 microm with birds or reptiles as final hosts (Sarcocystis and Frenkelia species of rodents) and those with large cystozoites of about 15 microm and mammals as final hosts (Sarcocystis spp. of domestic animals and rodents) would be more significative. The second group can be subdivided into monoxenous species (Isospora), species with an optional intermediate host in which no or only slight multiplication occurs (Cystoisospora) and in genera with a multiplication in two phases in the intermediate host (Hammondia, Toxoplasma, Besnoitia). The nomenclature of single species is very controversial. As an example the controversial apprehension of the taxonomy of the Sarcocystis species of cattle is discussed. An application has been submitted to the International Commission for the Zoological Nomenclature to delcare a number of names as nomina dubia and to introduce unambiguous names for those organisms for which type specimens are available.

Animals↗
PubMed1979

Serological cross-reactions between toxoplasma and hammondia.

Toxoplasma and Hammondia infected mice, dogs, rabbits, and pigs were tested for Toxoplasma antibodies by means of 5 serological methods. All Toxoplasma infected animals showed Toxoplasma-specific antibodies. Only sera of Hammondia infected mice and dogs showed positive serological reactions with Toxoplasma antigen in the SFT, CFT, and ELISA. IFAT and IHA, however, proved to be Toxoplasma-specific. The influence of Hammondia infections on the Toxoplasma serology is discussed.

Animals↗
PubMed1978

A comparison of cross protection between BCG, Hammondia hammondi, Besnoitia jellisoni and Toxoplasma gondii in hamsters.

The effect of pretreatment with BCG strain of Mycobacterium tuberculosis or Hammondia hammondi 21 days before challenge with lethal doses of T oxoplasma gondii and Besnoitia jellisoni was studied in hamsters. The results indicated that the intracardial administration of BCG provided no protection against either T. gondii or B. jellisoni. The hamsters immunized with H. hammondi survived challenge with 10(4) lethal doses of T. gondii but only 1 lethal dose with B. jellisoni, indicating strong cross protection between H. hammondi and T. gondii and only a marginal one between H. hammondi and B. jellisoni.

Animals↗
PubMed1977

Cross-immunity between Hammondia and Toxoplasma infections in mice and hamsters.

Cross-immunity between six strains of Hammondia hammondi and the M-7741 strain of Toxoplasma gondii was studied in mice and hamsters. Mice and hamsters were inoculated orally with 10(5) H. hammondi oocysts. All mice and hamsters survived. Four weeks later, they were challenged with 1 to 10(5) mean lethal doses (LD50) of the Toxoplasma oocysts. Animals that died were necropsied. Survivors were killed 30 days after challenge inoculation, and the number of cysts in brain and musculature was determined and compared with that of animals that were not immunized with H. hammondi. In one experiment, 36 mice were immunized with each of three H. hammondi strains. Four weeks later the mice were challenged with 1 to 10(5) LD50 doses of T. gondii oocysts. Of 108 mice immunized with H. hammondi, 103 survived challenge with Toxoplasma oocysts for 30 days, whereas only 3 of 36 unimmunized mice survived with similar doses of Toxoplasma oocysts. Fewer Toxoplasma cysts were found in mice immunized with H. hammondi than in unimmunized mice. In another experiment groups of six hamsters were each immunized with one of six H. hammondi strains and then challenged with 10(5) LD50 Toxoplasma oocysts. All unimmunized hamsters died between 9 and 13 days after inoculation. Percent protection in the various groups of immunized hamsters was: 100, 84, 66, 66, 50, and 33.

Animals↗
PubMedDate not supplied

[Toxoplasmids, their life cycle and systematic position].

Recent evidence on the life cycles of the toxoplasmids (Toxoplasma, Besnoitia, Sarcocystis, Hammondia, Frenkelia) has been analysed. The availability of the complex life cycles, including the alternation of sexual and asexual reproduction, in addition to gametogenesis involving the independent development of gametes that produce unequal numbers of gametes, makes it possible to include the toxoplasmids into the family Eimeriidae within the order Coccidiida. A detailed evidence recently provided for Isospora has suggested a kinship of this typical coccidian genus with toxoplasmids. At the same time much similarity is obvious between Isospora and Eimeria in the general pattern of their life cycles. Hence, the family Eimeriidae is suggested to be divided into two subfamilies: Eimeriinae Wenyon, 1926 with Eimeria as the type genus and Isosporinae Wenyon, 1926 with Isospora, Toxoplasma, Besnoitia, Sarcocystis, Frenkelia and Hammondia. The main features of the former subfamily are: various oocyst structures, the lack of the extra-intestinal development, obligatory monoxeny. The main characters of the latter subfamily: oocysts of the same pattern, the involvement of extra-intestinal development, shifts from facultative to obligatory heteroxeny.

Animals↗
PubMed1977

Tazonomy of Toxoplasma.

After reviewing reports of the hosts, structure and life cycle of Toxoplasma, the genus is placed in the apicomplexan family Eimeriidae and the folllowing 7 species are recognized: Toxoplasma gondii (Nicolle & Manceaux) (type species) from about 200 species of mammals and birds, with oocysts in felids; Toxoplasma alencari (Da Costa & Pereira) from the frog Leptodactylus ocellatus; Toxoplasma brumpti Coutelen from the iguana Iguana tuberculata; Toxoplasma colubri Tibaldi from the snakes Coluber melanoleucus and Coluber viridiflavus; Toxoplasma hammondi (Frenkel & Dubey) (a new combination for Hammondia hammondi) from the house mouse with oocysts in the domestic cat; Toxoplasma ranae Levine & Nye from the leopard frog Rana Pipiens; and Toxoplasma serpai Scorza, Dagert & Iturriza Arocha from the toad Bufo marinus.

Animals↗
PubMed1978

[The enzyme-linked immunosorbent assay (ELISA)--a new serodiagnostic method for the detection of parasitic infections (author's transl)].

The enzyme-linked immunosorbent assay (ELISA) is a new serodiagnostic aid for the indirect demonstration of parasites. Examples of the application of ELISA are given in a review of the literature. Antibodies against Babesia and Besnoitia could be detected in various domestic and laboratory animals. The application of ELISA for the detection of toxoplasma antibodies also under the influence of hammondia infections is discussed. Larva migrans visceralis could be demonstrated using ELISA in mono-infected mice and dogs, cross reactions with other helminth antibodies in human sera do not, however, permit a reliable diagnosis of larva migrans visceralis. The enzyme-linked immunosorbent assay may be recommended as a screening test for contamination investigations.

Animals↗
PubMed1977

Attempeted transmission of feline coccidia from chronically infected queens to their kittens.

Eight female, 12- to 34-month-old, specific-pathogen free cats were inoculated orally with Toxoplasma gondii cysts on day 0, then with Isospora felis and Isospora rivolta oocysts on day 39, and cysts of Hammondia hammondi on day 86 after inoculation with Toxoplasma. All cats shed oocysts of all 4 of these coccidia within 11 postinoculation days. The female cats were caged with 4 male Toxoplasma-free cats, starting 66 days after inoculation with Toxoplasma, until they were 5 to 6 weeks pregnant. Kittens that were born were housed with their mothers until necropsied or weaned. One 42-day-old kitten shed T gondii oocysts in feces. It was necropsied 2 days later and asexual stages of Toxoplasma (types D and E), gametocytes, and oocysts were demonstrated in sections of superficial epithelial cells of its small intestine. Lesions or forms of Toxoplasma were not demonstrated histologically in tis extraintestinal organs. Toxoplasma was not isolated from feces or tissues of the remaining 47 kittens born to these 8 queens. Toxoplasma was not isolated from the 4 male cats that were caged with infected females for 53, 59, 217, and 217 days. The source of toxoplasma infection in the kitten remained unknown but was considered unlikely to be congenital or through fecal contamination. Oocysts of I felis, I rivolta, and H hammondi were not found in the feces of any kittens, indicating that these coccidia are unlikely to be transmitted congenitally.

Animals↗