Dermatitis caused by autochthonous Cercopithifilaria bainae from a dog in Florida, USA: clinical, histological and parasitological diagnosis and treatment.

BACKGROUND: Cercopithifilaria bainae is a tick-vectored filarioid nematode associated with erythematous dermatitis in dogs. It has not been reported previously in the United States. HYPOTHESIS/OBJECTIVE: To describe clinical, histological and parasitological diagnosis and treatment of C. bainae in a dog. ANIMALS: An 11-month-old golden retriever/standard poodle mixed breed dog from Florida (USA). METHODS AND MATERIALS: The dog had no travel history within or outside the United States, was presented with a one month history of annular erythematous plaques on the head and ulcers on the medial canthi. Lesions were unresponsive to antibiotic treatment. RESULTS: Histopathological evaluation of skin biopsies revealed an eosinophilic to lymphohistiocytic perivascular dermatitis with multiple microgranulomas and rare 5-10 µm diameter microfilariae within microgranulomas. Microfilarial morphology was consistent with C. bainae. PCR and sequencing of 18S rRNA and mitochondrial cytochrome oxidase subunit I genes confirmed the nematodes as C. bainae. The dog was treated with a commercial spot-on containing imidacloprid and moxidectin, and clinical resolution occurred. CONCLUSIONS AND CLINICAL IMPORTANCE: To the best of the authors' knowledge, this is the first report of C. bainae in a dog in the United States and the first description of dermatological lesions caused primarily by C. bainae.

A new species of Tritrichomonas (Sarcomastigophora: Trichomonida) from the domestic cat (Felis catus).

Feline trichomoniasis is an intestinal disease in cats resulting in chronic diarrhea, flatulence, tenesmus, and fecal incontinence. Bovine trichomoniasis is a sexually transmitted disease of cattle infecting the reproductive tract of cows causing pyometra and possible mid- to late-term abortions. The causative agent for both diseases has been reported to be the flagellated protozoan, Tritrichomonas foetus. However, several published reports support significant biological differences between T. foetus isolated from bovines and felines. In the present study, we describe Tritrichomonas blagburni n.sp. from the domestic cat (Felis catus) as the causative agent of feline intestinal trichomoniasis. We support our proposal based on results of experimental cross-infection studies between cats and cattle using both feline and bovine isolates of the parasite, differences in pathogenicity between the two parasites for the respective host species, and molecular gene sequencing differences between parasites obtained from domestic cats and parasites obtained from cattle.

Systemic humoral immunity in beef bulls following therapeutic vaccination against Tritrichomonas foetus.

The utility of therapeutic vaccination of bulls against Tritrichomonas foetus has been advocated in previous studies, but anecdotal reports suggest this practice does not clear infections and may additionally confound diagnostic testing by reducing parasite burdens below detectable limits. The objective of this study was to characterize the systemic humoral immune response to therapeutic vaccination in T. foetus-infected bulls over a period of four months using an indirect ELISA and to compare the dynamics of this response to culture and PCR results to establish the existence of a relationship (or lack thereof) between immunization and infection status. A study population of 4- to 6-year-old T. foetus-infected beef bulls (n = 20) was divided equally into a treatment group and a control group. The treatment group received two doses of commercially prepared whole cell killed vaccine 2 weeks apart while the control group received injections of vaccine diluent. Blood samples were collected at each injection and at 4 subsequent dates every 4 weeks thereafter (i.e. 0, 2, 6, 10, 14, and 18 wks) to measure IgG1 and IgG2 antibody subisotype response via an indirect ELISA. Preputial smegma samples were collected at the four monthly intervals following vaccination for diagnosis of infection via InPouch™ culture, Modified Diamond's Medium (MDM) culture, and PCR. Humoral response for both IgG isotypes from week 2 through week 18 were significantly increased in vaccinates compared to controls. No significant decrease in infection prevalence was detected in the treatment group for any of the diagnostic methods used. The apparent lack of pathogen clearance during a stimulated immune response suggests that therapeutic vaccination may not be a useful T. foetus management practice.

Infection with a novel derogenid trematode in a Flap-necked chameleon (Chamaeleo dilepis).

A 2-year-old female Flap-necked chameleon (Chamaeleo dilepis) was presented with a history of anorexia. On physical examination, three 11×4×2 mm, light tan-pink, raised, gelatinous, freely movable, poorly demarcated, raised nodules were identified within the oral cavity. An impression smear contained multiple, light blue to green structures exhibiting an 18×35 µm, elliptical-shaped anterior portion and a single 1×150 µm filament with a tapered end. Initial differential etiologies included trematode ova, flagellate protozoa, fungal sporangia, plant material, and sperm. Fungal culture yielded no growth. The structures described above did not stain with Gomori methenamine silver stain. A calcofluor white stain yielded positive fluorescence. The DNA was extracted from the impression smears and pan-trematode PCR was performed; products were directly sequenced and phylogenetic analysis revealed maximum similarity with a digenean trematode in the family Derogenidae that was distinct from other trematodes for which a reference sequence was available. To our knowledge, this is the first description of cytologic features of trematode ova from an oral lesion in a chameleon.

COCCIDIAL INFECTION OF THE ADRENAL GLANDS OF LEATHERBACK SEA TURTLES (DERMOCHELYS CORIACEA).

Histologic lesions incidental to the cause of death were observed in the adrenal glands of 17 subadult and adult leatherback sea turtles ( Dermochelys coriacea ) found dead or moribund on or near shore in North America. Round bodies, 250-300 µm in diameter composed of an outer capsule and large multinucleated cells surrounding a central mass of acellular material were distributed throughout the affected glands. Protozoal etiology was suspected based on some resemblance to coccidia; however, features diagnostic for coccidial infection were lacking in all but one case, which had a focal area of adrenalitis containing zoites. A novel eucoccidian partial 18S rRNA genetic sequence was consistently detected in adrenal glands with lesions. With the use of quantitative PCR, a specific area of the V4 region of the coccidian 18S gene was quantified in affected adrenal glands and correlated significantly with density of the histologic lesions. A second distinct, but closely related, 18S sequence was also amplified from the adrenal gland of one turtle and from a fecal sample containing unsporulated coccidian oocysts. The two 18S sequences identified from leatherback sea turtles form a clade within the family Eimeriidae. Further investigation is required to understand better the morphology of the life stages, life cycle, and potential effects of this coccidian parasite on adrenal function.