Cerebral toxoplasmosis in a cat with feline leukemia and feline infectious peritonitis viral infections.

A diarrheic young cat died after neurological involvement. Biochemistry pointed to feline infectious peritonitis (FIP). The final diagnosis was severe multifocal meningoencephalitis due to Toxoplasma gondii. The presence of the parasite in the brain was confirmed using immunohistochemical staining. Concomitant feline leukemia virus (FeLV) and FIP were possible contributors to the clinical, fatal outcome.

Toxoplasmose cérébrale chez un chat atteint des infections virales de leucémie féline et de péritonite infectieuse féline. Un jeune chat diarrhéique est mort après des symptômes neurologiques. La biochimie a signalé une péritonite infectieuse féline (FIP). Le diagnostic final a été une méningo-encéphalite multifocale grave causée par Toxoplasma gondii. La présence du parasite dans le cerveau a été confirmée à l'aide de la coloration immunohistochimique. La présence concomitante du virus de la leucémie féline (FeLV) et de la FIP sont des facteurs possibles ayant contribué au résultat clinique mortel.(Traduit par Isabelle Vallières).

Molecular detection of Toxoplasma gondii in snakes.

Toxoplasma gondii, an obligate intracellular protozoan parasite, is responsible for one of the most common zoonotic parasitic diseases in almost all warm-blooded vertebrates worldwide, and it is estimated that about one-third of the world human population is chronically infected with this parasite. Little is known about the circulation of T. gondii in snakes and this study for the first time aimed to evaluate the infection rates of snakes by this parasite by PCR methods. The brain of 68 Snakes, that were collected between May 2012 and September 2015 and died after the hold in captivity, under which they were kept for taking poisons, were examined for the presence of this parasite. DNA was extracted and Nested-PCR method was carried out with two of pairs of primers to detect the 344 bp fragment of T. gondii GRA6 gene. Five positive nested-PCR products were directly sequenced in the forward and reverse directions by Sequetech Company (Mountain View, CA). T. gondii GRA6 gene were detected from 55 (80.88%) of 68 snakes brains. Sequencing of the GRA6 gene revealed 98-100% of similarity with T. gondii sequences deposited in GenBank. To our knowledge, this is the first study of molecular detection of T. gondii in snakes and our findings show a higher frequency of this organism among them.

Cerebral toxoplasmosis in striped dolphins (Stenella coeruleoalba) stranded along the Ligurian Sea coast of Italy.

This article reports the results of necropsy, parasitologic, microbiologic, histopathologic, immunohistochemical, indirect immunofluorescence, biomolecular, and serologic investigations on 8 striped dolphins (Stenella coeruleoalba) found stranded from August to December 2007 on the Ligurian Sea coast of Italy. Severe, nonsuppurative meningoencephalitis was found in 4 animals, as characterized by prominent perivascular mononuclear cell cuffing and macrophage accumulations in neuropil. These lesions were associated with mild lymphocytic-plasmacytic infiltration of choroid plexuses in 1 dolphin. Toxoplasma gondii cysts and zoites, confirmed by immunohistochemical labeling, were scattered throughout the brain parenchyma of 2 of the 4 dolphins. No viral inclusions were seen in the brain of any animal. Other findings included severe bronchointerstitial pneumonia and pulmonary atelectasis, consolidation, and emphysema. Parasites were identified in a variety of organs, including lung (Halocerchus lagenorhynchi). Microbiologic and serologic examinations for Brucella spp were negative on all 8 dolphins. The 4 animals with meningoencephalitis had serum antibodies against T gondii (titers ranging from 1:80 to 1:320) but not against morbillivirus. In contrast, the other 4 dolphins were seropositive for morbillivirus (with titers ranging from 1:10 to 1:40) but seronegative for T gondii. No morbillivirus antigen or nucleic acid was detected in the tissues of any dolphin. It is concluded that the severe lung and brain lesions were the cause of death and that T gondii was the likely etiologic agent of the cerebral lesions. Morbillivirus infection was not considered to have contributed to death of these animals.

Protection against Toxoplasma gondii brain cyst formation in mice immunized with Toxoplasma gondii cytoskeleton proteins and Lactobacillus casei as adjuvant.

The aim of the study was to evaluate the protection generated in mice against Toxoplasma gondii brain cyst burden by vaccination with T. gondii cytoskeleton proteins using Lactobacillus casei as adjuvant. One hundred and sixty-eight NIH mice were randomly allocated into eight groups of 21 mice each. Animals were immunized as follows: in group 1 with Toxoplasma lysate antigen (TLA) in Freund's modified adjuvant, containing L. casei (FMA), in group 2 with Toxoplasma cytoskeleton proteins (TCPs) in FMA, in group 3 with FMA, in group 4 with phosphate buffered saline (PBS), in group 5 with L. casei dead by heath (Lc), in group 6 with Freund's complete adjuvant (FCA), in group 7 with TLA in FCA, and in group 8 with TCP in FCA. Mean brain cyst burden (+/-S.E.M.) was assessed in mice 8 weeks after challenge with T. gondii Me49 strain (20 cysts per mouse). The percentages of reduction in cyst burden per brain (P<0.01) as compared with the group 4 (control: mean 3181+/-97.5) were 77.25% (724+/-98) in group 1, 88.02% (381+/-97.5) in group 2, 38.92% (1943+/-130.3) in group 3, 44.31% (1771.4+/-102) in group 5, 59.28% (1295.2+/-99.1) in group 7 and 55.69% (1409.5+/-89.9) in group 8. In order of importance, the best protection was obtained in groups 2, 1, 7, 8, 5 and 3. Noticeably the mice inoculated with L. casei alone showed a significant reduction in T. gondii brain cysts (P<0.01), while those animals treated with FCA alone did not. Additionally, IgM anti-T. gondii antibody levels, as determined by ELISA 2 weeks after challenge, were highest in group 2 (P<0.01) than in the other seven groups. Results suggest that T. gondii cytoskeleton proteins with L. casei as adjuvant constitute a good anti-toxoplasmosis vaccine candidate.

Toxoplasmosis in captive dolphins (Tursiops truncatus) and walrus (Odobenus rosmarus).

Toxoplasma gondii infection in marine mammals is intriguing and indicative of contamination of the ocean environment and coastal waters with oocysts. Toxoplasma gondii infection was detected in captive marine mammals at a sea aquarium in Canada. Antibodies to T. gondii were found in all 7 bottlenose dolphins (Tursiops truncatus) tested. Two of these dolphins, as well as a walrus (Odobenus rosmarus) at the facility, died. Encephalitis and T. gondii tissue cysts were identified in histological sections of the brain of 1 dolphin (dolphin no. 1). Another dolphin (dolphin no. 2) had mild focal encephalitis without visible organisms, but viable T. gondii was isolated by bioassay in mice and cats from its brain and skeletal muscle; this strain was designated TgDoCA1. The PCR-RFLP typing using 11 markers (B1, SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) identified a Type II strain. The DNA sequencing of B1 and SAG1 alleles amplified from TgDoCA1 and directly from the brains of dolphin no. 1 and the walrus showed archetypal alleles consistent with infection by a Type II strain. No unique polymorphisms were detected. This is apparently the first report of isolation of T. gondii from a marine mammal in Canada.

Toxoplasma gondii brain granuloma in a cat: diagnosis using cytology from an intraoperative sample and sequential magnetic resonance imaging.

A cat with a history of seizures and clinical suspicion of forebrain disorder underwent a brain magnetic resonance imaging. A space-occupying lesion was identified in the left temporal lobe. The mass was surgically removed, and cytological, histological and immunohistochemical examinations documented the presence of Toxoplasma gondii. A definitive diagnosis of an intracranial T gondii granuloma was made. The cat was treated with clindamycin and phenobarbital and the seizures did not recur. After 10 months, a second magnetic resonance imaging showed severe brain atrophy, but T gondii granuloma recurrence was not noted. Twenty-one months after surgery, the cat's condition deteriorated, and another magnetic resonance imaging showed a presumptive recurrence of T gondii granuloma. In cats, T gondii granuloma must be considered as a differential diagnosis even when only a single intracranial mass is present. Cytology and magnetic resonance imaging can be useful in making a definitive diagnosis and to follow the evolution of the lesion.

Prevalence of cerebral toxoplasmosis among slaughtered sheep in Semnan, Iran

Toxoplasmosis is a zoonotic disease caused by Toxoplasma gondii. Felids are definitive hosts and all warm-blooded animals can be intermediate hosts. Some animals such as sheep, goats and pigs are sensitive to infection. In sheep production systems, toxoplamosis can cause abortion and economic loss. In public health, this disease can be transmitted to humans by the consumption of undercooked infected meat or other organs. In this study, T. gondii DNA was detected by B1 gene amplification in 140 randomly-selected brains of slaughtered sheep in Semnan, Iran. The prevalence of ovine cerebral toxoplasmosis was estimated using 95% confidence interval. The brain was selected as a target organ because it gives the highest detection rates, and the results can be compared with previous data from other countries. Our findings indicate that T. gondii is present in ovine tissues and can be passed on to humans by consuming undercooked or raw meat and other organs such as the liver. The infection can be lethal for immunosuppressed individuals and can cause abortion or birth of infected children in pregnant woman.

Results of magnetic resonance imaging in 14 cats with meningoencephalitis.

Medical records and magnetic resonance (MR) images of 14 cats with inflammatory diseases affecting the central nervous system (CNS) were reviewed retrospectively. Cases included eight cats with feline infectious peritonitis and two cats with toxoplasmosis. Abnormalities affecting the CNS were observed in MR images in 10 (71%) cats. Intracranial lesions appeared as slightly hypointense foci in T1-weighted images in two (14%) cats, as hyperintense foci in T2-weighted images in seven (50%) cats and as hyperintense foci after intravenous administration of a gadolinium-based contrast medium in 10 (71%) cats. In six cats with lesions in T1- and/or T2-weighted images, additional lesions were visible in T1-weighted images obtained after gadolinium-based contrast medium administration. In three cats, lesions were visible only after contrast medium administration. In our study, MR imaging (MRI) did not appear to detect all cases of CNS inflammation in the population of cats with inflammatory cerebrospinal fluid (CSF); however, MRI adds information about the sites and morphology of intracranial lesions that should help to distinguish between neoplasia and inflammatory conditions and, possibly, between different inflammatory conditions.

Hypernatremia in a Cat with Toxoplasma-Induced Panencephalitis.

A 12 yr old female neutered Carthusian crossbreed cat was presented due to progressive neurological signs. Clinical signs included dehydration, stupor, and anisocoria. Laboratory examination revealed severe hypernatremia, azotemia, hyperglobulinemia, and an erythrocytosis. Clinical signs and hypernatremia suggested an intracranial process. Imaging studies revealed a loss of structure in the cerebrum, hypothalamus, and pituitary gland. Due to a poor prognosis, the cat was euthanatized. Histopathological examination revealed a subacute granulomatous and necrotizing panencephalitis with Toxoplasma-typical protozoa. The Toxoplasma-induced dysfunction of the hypothalamus and pituitary gland led to diabetes insipidus, which was, in combination with insufficient water intake, the most likely cause for the hypernatremia.

Intracranial Toxoplasma gondii granuloma in a cat.

An 8-year-old cat with recent-onset generalized seizures was diagnosed with a right forebrain mass using magnetic resonance imaging. The mass was excised and upon histologic and immunohistochemical examination shown to be a Toxoplasma gondii granuloma. Serology supported active T gondii infection. The cat was treated with phenobarbital to control seizures. After definitive diagnosis of toxoplasma granuloma, clindamycin was administered for approximately 1 month. Seizures recurred 8 months after initial presentation, and the cat was euthanased at the owner's request. This is a previously unreported manifestation of feline central nervous system toxoplasmosis. When a mass lesion is present in the brain of a cat and serologic test results support active infection with T gondii, toxoplasma granuloma must be a differential diagnosis. If the patient is suffering from clinical disease, surgical resection of the mass (if possible) can be complimented with medical treatment until definitive diagnosis is obtained. Immunocompromising factors should be identified and addressed if possible.

Ocular and encephalic toxoplasmosis in canaries.

In this report we describe the lesions produced by the protozoal organism, Toxoplasma gondii, in the eyes and brain of the common yellow canary (Serinus canaria). Nine of 15 birds in a flock were affected with blindness, which developed over a 3-mo span, and two birds developed torticollis. Microscopic alterations within the eye consisted of a nonsuppurative chorioretinitis with large numbers of macrophages that contained the tachyzoite form of T. gondii in the subretinal space, and aggregates of tachyzoites were found in the nerve fiber layer of the retina with and without necrosis. Tissue cysts with bradyzoites were scattered throughout the meninges and neuropil of the cerebrum and cerebellum. Both forms were confirmed by transmission electron microscopy in the eye and brain. Frozen brain samples reacted with T. gondii-specific cat sera in indirect fluorescent antibody tests. The source of infection was hypothesized to be from a stray cat the owner kept that had access to some of the bird feed. Treatment (trimethoprim 0.08 g/ml H2O and sulfadiazine 0.04 g/ml in water for 2 wk) was instituted by the referring veterinarian on the remaining birds. A second treatment regime was given for 3 wk. The owner of the canaries did not return for further treatment.

Toxoplasmosis in an elephant seal (Mirounga angustirostris).

Toxoplasma gondii infections in fish-eating marine mammals is intriguing and indicative of contamination of the sea environment with oocysts. Toxoplasma gondii was identified in an elephant seal (Mirounga angustirostris) that had encephalitis. Tissue cysts were found in sections of cerebrum, and the diagnosis was confirmed by immunohistochemical staining with T. gondii-specific polyclonal rabbit serum. This is the first report of T. gondii infection in an elephant seal.

Patterns of mortality in southern sea otters (Enhydra lutris nereis) from 1998-2001.

Detailed postmortem examination of southern sea otters (Enhydra lutris nereis) found along the California (USA) coast has provided an exceptional opportunity to understand factors influencing survival in this threatened marine mammal species. In order to evaluate recent trends in causes of mortality, the demographic and geographic distribution of causes of death in freshly deceased beachcast sea otters necropsied from 1998-2001 were evaluated. Protozoal encephalitis, acanthocephalan-related disease, shark attack, and cardiac disease were identified as common causes of death in sea otters examined. While infection with acanthocephalan parasites was more likely to cause death in juvenile otters, Toxoplasma gondii encephalitis, shark attack, and cardiac disease were more common in prime-aged adult otters. Cardiac disease is a newly recognized cause of mortality in sea otters and T. gondii encephalitis was significantly associated with this condition. Otters with fatal shark bites were over three times more likely to have pre-existing T. gondii encephalitis suggesting that shark attack, which is a long-recognized source of mortality in otters, may be coupled with a recently recognized disease in otters. Spatial clusters of cause-specific mortality were detected for T. gondii encephalitis (in Estero Bay), acanthocephalan peritonitis (in southern Monterey Bay), and shark attack (from Santa Cruz to Point Año Nuevo). Diseases caused by parasites, bacteria, or fungi and diseases without a specified etiology were the primary cause of death in 63.8% of otters examined. Parasitic disease alone caused death in 38.1% of otters examined. This pattern of mortality, observed predominantly in juvenile and prime-aged adult southern sea otters, has negative implications for the overall health and recovery of this population.

Toxoplasmic encephalitis in a free-ranging Rocky Mountain bighorn sheep from Washington.

A 4-mo-old free-ranging Rocky Mountain bighorn sheep (Ovis canadensis canadensis) from the Hells Canyon area (Washington, USA) was diagnosed with encephalitis associated with Toxoplasma gondii infection. The sheep had concurrent pneumonic pasteurellosis and resided in a geographic area with endemic Pasteurella-associated pneumonia and mortality in bighorn sheep. The brain had multifocal necrotizing and nonsuppurative encephalitis with intralesional protozoa. The protozoa were identified as T. gondii by immunohistochemistry. To our knowledge, this is the first report of T. gondii infection in a Rocky Mountain bighorn sheep.

Genotyping of Toxoplasma gondii isolates in meningo-encephalitis affected striped dolphins (Stenella coeruleoalba) from Italy.

This study reports the occurrence of Toxoplasma gondii in the brain of three striped dolphins (Stenella ceoruleoalba) found stranded on the Ligurian Sea coast of Italy between 2007 and 2008. These animals showed a severe, subacute to chronic, non-purulent, multifocal meningo-encephalitis, with the cerebral parenchyma of two dolphins harbouring protozoan cysts and zoites immunohistochemically linked to T. gondii. Molecular, phylogenetic and mutation scanning analyses showed the occurrence of Type II and of an atypical Type II T. gondii isolates in one and two dolphins, respectively. In spite of the different molecular patterns characterizing the above T. gondii genotypes, the brain lesions observed in the three animals showed common microscopic features, with no remarkable differences among them. The role of T. gondii in causing the meningo-encephalitis is herein discussed.

[New pathogens and mode of action of azithromycin: Toxoplasma gondii]. / Les nouveaux pathogènes et le mode d'action de l'azithromycine: Toxoplasma gondii.

Azithromycin can inhibit the growth of Toxoplasma gondii tachyzoïtes in vitro, but the effect is only observed with prolonged incubation with the drug, reflecting the delayed mode of action of this macrolide on the parasite. Azithromycin is probably acting by inhibition of protein synthesis but the site of action and fixation in the parasite has not been demonstrated. Azithromycin is also effective against intracystic bradyzoïtes in vitro, but long term administration of azithromycin to chronically infected mice failed to reduce the mean number of brain cysts. In models of acute toxoplasmosis, azithromycin was found to have a limited effect on brain infection, whereas parasites were cleared from blood and lungs of infected mice, resulting in a significant protection of treated mice comparatively to untreated controls. When azithromycin is combined with pyrimethamine or sulfadiazine, an additive effect is observed in vitro, and a remarkable synergistic effect is observed in vivo in the treatment of acute toxoplasmosis. Together, these results are in favor of the use of azithromycin in combined therapies for the treatment and/or prophylaxis of toxoplasmosis.

The dural tail sign in the diagnosis of meningiomas.

In humans the dural tail is a sign seen on contrast enhanced T1 weighted magnetic resonance images. This finding is considered specific for meningioma. The purpose of this study was to determine how often the dural tail occurs in cats and dogs and whether it is a specific sign for meningiomas in these species. MR examinations for eighteen dogs and four cats with proven diagnoses were reviewed. Diagnoses included ten meningiomas (seven dogs and three cats), three gliomas, two pituitary tumors, single examples of two other tumor types and five patients with mass lesions due to inflammatory disease. Contrast enhanced T1 weighted images were evaluated independently by three of the authors for the presence of a dural tail, without knowledge of the diagnoses. The results were compared to the diagnosis for each patient and the performance of individual reviewers compared. When their results were averaged, the reviewers reported the presence of a dural tail in 6 of 10 (60%) meningiomas, although detection varied between observers from 40% to 80%. Each reviewer had one false positive result, two reported a dural tail with a chromophobe adenocarcinoma and one with a toxoplasma meningoencephalitis. When a dural tail is seen an associated mass is most likely a meningioma. It is uncertain whether the dural tail represents neoplastic infiltration beyond the margins of the meningioma. This should be considered when planning treatment.