Toshihiro Tokiwa

The Occurrence and Ape-to-Ape Transmission of the Entodiniomorphid Ciliate Troglodytella abrassarti in Captive Gorillas

ABSTRACT. Entodiniomorphid ciliates are often present in the colons of wild apes. In captive apes the infection tends to gradually disappear, with the exception of Troglodytella abrassarti. We used fecal examinations to screen the gorillas (Gorilla gorilla gorilla) in European (Czech Republic, UK) and Australian Zoos to explore the ape‐to‐ape transmission pattern of T. abrassarti. Gorillas from two out of three European Zoos were positive for T. abrassarti, while gorillas from the Australian Zoo were negative. We documented a horizontal transmission of T. abrassarti to a non‐infected adult gorilla introduced into a Troglodytella‐positive group in the Prague Zoo and traced the origin of the ciliate infection to the Paignton Zoo (UK) using serial fecal examinations. During this study, two infant gorillas born in the Prague Zoo (CZ) first became positive for T. abrassarti at the age of 9 mo. Ciliate morphology and the sequencing of the small subunit rRNA gene and the internal transcribed spacer rDNA spacer region revealed that T. abrassarti affects both captive gorillas and chimpanzees. We conclude that zoo transport plays a major role in the distribution of T. abrassarti among captive gorillas.

Prototapirella ciliates from wild habituated Virunga mountain gorillas (Gorilla beringei beringei) in Rwanda with the descriptions of two new species

The morphology of Prototapirella fosseyi n. sp., P. rwanda n. sp. and P. gorillaeImai, Ikeda, Collet, and Bonhomme, 1991 in the Entodiniomorphida were described from the mountain gorillas, Gorilla beringei beringei, in Rwanda. The ciliates have a retractable adoral ciliary zone, four non-retractable ciliary tufts in four caudalia, and one broad skeletal plate beneath the body surface. P. rwanda has a dorsal lobe and ventral lobes in two rows whereas P. fosseyi has no lobes. These two new species have an elongated body, a flat tail flap leaning to the ventral, a macronucleus with a tapering anterior end, a round posterior end and a shallow depression on the dorsal side, a micronucleus lying near the anterior end of macronucleus, a thin left region of the skeletal plate, a distinct skeletal rod plate, and four contractile vacuoles. P. gorillae has some variations in the nuclei and the skeletal plate. The infraciliary bands of three Prototapirella species were the same as some Triplumaria species; a C-shaped adoral polybrachykinety, a slender perivestibular polybrachykinety, and paralabial kineties in their retractable adoral ciliary zone and short lateral polybrachykineties in their four caudalia. The perivestibular polybrachykinety is joined only to the right end of adoral polybrachykinety.

Isospora lunaris n. sp. (Apicomplexa: Eimeriidae) from the domestic Java sparrow in Japan

Five individuals of the domestic Java sparrows, Lonchura oryzivora (Aves: Estrildidae), were examined for coccidian parasites. Sporulated oocysts had two sporocysts containing four sporozoites each. Sporulated oocysts (n=30) were spherical, with a two splinter-like polar granules. Oocyst size was 22.1×20.7 (20.0-25.0×20.0-22.5)μm. They had a thick wall that consisted of a pale yellow outer layer and a dark yellow inner layer, and lacked micropyle and residuum. Sporocysts (n=60) were elongated ovoid 14.1×9.8 (12.5-15.0×7.5-10.0)μm, smooth walled, and colorless, with crescent-shaped Stieda and indistinct substieda bodies. Sporocyst residuum was interspersed between sporozoites. Sporozoites were oriented transverse to the sporocyst longitudinal axis. On the basis of morphological data, the species isolated in the present study is a new species of Isospora and propose the name Isospora lunaris n. sp.

Gorilloflasca africana n.g., n.sp., (Entodiniomorphida) from wild habituated Virunga mountain gorillas (Gorilla beringei beringei) in Rwanda

A new entodiniomorphid ciliate species, Gorilloflasca africana n. g., n. sp. was described from the Virunga mountain gorillas, Gorilla beringei beringei, in Rwanda. It is characterized by a flask-shaped body, a long tubular vestibulum, a round frontal lobe, a large posterior cavity, an ellipsoidal or peanut-shaped macronucleus and a single contractile vacuole. G. africana has the adoral and the vestibular ciliary zones in the buccal area. The adoral ciliary zone is non-retractable, encircling the vestibular opening. The vestibular ciliary zone extends posteriorly in the vestibulum. The somatic ciliary zones are the cavity ciliary zone in the posterior cavity along the ventral side of its opening and two longitudinal ciliary zones on the dorsal body surface. The buccal infraciliary bands of G. africana are a C-shaped adoral polybrachykinety, a stick-shaped vestibular kinety band, and paralabial kineties. The anterior region of the vestibular kinety band is composed of short kineties whereas, kineties in the remaining region are longitudinal. The somatic infraciliary bands are a cavity polybrachykinety and two longitudinal polybrachykineties. Gorilloflasca is a member of the family Blepharocorythidae based on the non-retractable adoral ciliary zone, the frontal lobe, the large posterior cavity and the vestibular longitudinal kineties.

Tetragomphius melis Infection of the Pancreas in Japanese Badger (Meles meles anakuma)

Hisashi Yoshimura, Yoko Matsuda, Masami Yamamoto, Tomohiko Endo, Hiroshi Kajigaya, Toshihiro Tokiwa, Toshiyuki Ishiwata and Shinji Kamiya Division of Physiological Pathology, Department of Applied Science, School of Veterinary Nursing and Technology, Nippon Veterinary and Life Science University Department of Pathology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology Division of Conservation Biology, Department of Applied Science, School of Veterinary Nursing and Technology, Nippon Veterinary and Life Science University Division of Pathobiological Analysis, Department of Veterinary Pathobiology, School of Veterinary Medicine, Nippon Veterinary and Life Science University Department of Integrated Diagnostic Pathology, Graduate School of Medicine, Nippon Medical School Division of Animal Higher Function, Department of Applied Science, School of Veterinary Nursing and Technology, Nippon Veterinary and Life Science University

Oxalate nephropathy in free-living American bullfrog tadpoles

In February 2014, wild American bullfrog Lithobates catesbeianus tadpoles from an artificial pond in the Kyusyu region, Japan, presented with coelomic and subcutaneous edema and erythema within the skin. A pathological examination of 57 tadpoles of American bullfrogs in the region was conducted to evaluate the disease. Crystal deposition of varying degrees was found in the kidneys of 35 tadpoles (61.4%). The crystals were transparent, pleomorphic in shape, highly birefringent in polarized light, and arranged in a radial pattern within the renal tubular lumen. Using Alizarin Red S stain and liquid chromatography, these crystals were identified as calcium oxalate. Severe coelomic and subcutaneous edema was observed in 7 of these 35 tadpoles (20.0%). Ammonia levels in coelomic fluid were extremely elevated (>1000 µg dl(-1)) in 4 tadpoles examined. These findings suggest that oxalate deposition in kidneys causes metabolic disorder with renal nephropathy. The source of the oxalate could not be determined; however, the presence of calcium oxalates in pond sediments, as revealed by liquid chromatography, suggested that the deposition was most likely due to ingestion of oxalate materials from the environment. This is the first report of oxalate nephropathy in free-living amphibians.

Molecular and histopathological features of Cryptosporidium ubiquitum infection in imported chinchillas Chinchilla lanigera in Japan

Long-tailed chinchillas Chinchilla lanigera are popular rodent species kept both in households, where they are hand-raised as pets, and in zoological facilities. From January 2016 to February 2017, 13 juvenile chinchillas from five facilities in Japan were diagnosed with cryptosporidiosis at the animal hospital. Eight of the cases were fatal. All of the animals were imported from the Czech Republic by the same vendor. Histopathological and multilocus sequence analyses using 18S ribosomal RNA, actin, 70-kDa heat shock protein, and 60-kDa glycoprotein genes confirmed Cryptosporidium ubiquitum of subtype XIId as the etiological agent. Multilocus analysis demonstrated the presence of two new sequence types closely related to the C. ubiquitum Xlld strain isolated from a human in the USA. This study indicated that potentially zoonotic Cryptosporidium is widespread and may have caused a high number of deaths among imported juvenile chinchillas.

Larva Migrans of Baylisascaris potosis In Experimental Animals

Abstract Occurrence of clinical signs by infection with Baylisascaris potosis, the roundworm of kinkajous (Potos flavus), in mice, rats, and rabbit were studied, and the migration behavior of larvae in mice were compared with that of Baylisascaris transfuga, the roundworm of bears (Ursus spp.). Three groups of 8 mice, 3 groups of 6 rats, and 3 groups of 2 rabbits were inoculated with either 10, 100, or 1,000 B. potosis eggs. The other 8 mice were inoculated with 1,000 B. transfuga eggs. Animals were monitored for the occurrence of clinical signs until 60 days postinoculation (DPI). The carcass, viscera, brain, and eyes of each of 6 mice inoculated with 1,000 eggs of B. potosis or B. transfuga at 60 DPI were removed individually, and the number of larvae was counted. One mouse inoculated with 100 B. potosis eggs showed rolling at 27 DPI, and 1 larva was found in the medulla oblongata of this mouse. No clinical signs were observed in the other mice or in the rats and rabbits. A mean of 387.2 larvae was recovered from mice inoculated with 1,000 B. potosis eggs, and a mean of 422.0 larvae from mice inoculated with 1,000 B. transfuga eggs. The highest number of larvae was recovered from the carcasses for both B. potosis and B. transfuga. In the viscera, higher numbers of B. transfuga larvae (mean 131.8) were seen than B. potosis larvae (mean 33.1). In the brain, only 1 larva was detected in 1/6 mice inoculated with 1,000 B. potosis eggs, whereas a mean of 21 larvae was detected in mice inoculated with 1,000 B. transfuga eggs. A few larvae (range 0–1) were detected in the eyes of both mice inoculated with B. potosis or B. transfuga eggs. The result indicated that B. potosis larvae do not show a higher tendency to migrate into the brain of mice than B. transfuga larvae. However, 1 mouse inoculated with 100 eggs had 1 larva in the central nervous system and showed a serious neurological sign. This result may underline a potential risk of B. potosis to cause neural larva migrans in humans.

Morphological and molecular characterization of Cystoisospora sp. from Asian small-clawed otters Aonyx cinereus

In this study, we provide the first description of Cystoisospora infection in Asian small-clawed otters (Aonyx cinereus). In July 2017, three juvenile otters recently imported from the Republic of Indonesia showed severe diarrhea and were diagnosed with coccidial infection; two of them eventually died. Fecal examination revealed the presence of numerous oocysts. Sporulated oocysts showed typical Cystoisospora features, measuring 24.6 ± 1.6 (22.0–27.0) × 21.8 ± 1.4 (19.0–25.0) μm, with an oocyst length/width ratio of 1.1 ± 0.1 (1.0–1.3). Each sporocyst contained four sporozoites in a head-to-tail arrangement. The Stieda body was absent, and the sporocyst residuum was present. These morphological characteristics differentiated this species from the other valid Cystoisospora species described from mustelids. Molecular analysis was conducted at two loci: the nuclear 18S ribosomal RNA and mitochondrial cytochrome c oxidase subunit I genes. The 18S sequence showed high similarity with canine Cystoisispora ohioensis (1-bp difference, 1422/1423 [99.9%]). At the cytochrome c oxidase subunit I gene locus, the sequence from otters was identical to that of feline Cystoisospora rivolta (847/847 [100%]). Phylogenetic analyses using concatenated data demonstrated that Cystoisospora sp. from otters and C. rivolta grouped together in the same Cystoisospora clade. Based on these data, we concluded that Cystoisospora sp. detected from otters appeared to be highly similar to C. rivolta.

Infraciliature of Opisthotrichum janus , Epidinium ecaudatum , and Ophryoscolex purkynjei (Ciliophora, Entodiniomorphida)

We described the infraciliature of Opisthotrichum janus, Epidinium ecaudatum, and Ophryoscolex purkynjei, belonging to the family Ophryoscolecidae, from pyridinated silver carbonate impregnated specimens. The adoral polybrachykinety is C-shaped in Opi. janus, whereas it is spiral-shaped in Epi. ecaudatum and Oph. purkynjei. The vestibular polybrachykinety is slender and short in Opi. janus, whereas slender and long in Epi. ecaudatum and Oph. purkynjei. The paralabial kineties are composed of several short kineties along the adoral polybrachykinety. The dorsal polybrachykinety is displaced posteriorly. This study provides information on the diagnostic features of the subfamily Ophryoscolecinae to which Opi. janus, Epi. ecaudatum, and Oph. purkynjei belong. A C-shaped or spiral-shaped adoral polybrachykinety and slender vestibular polybrachykinety are the diagnostic features of the subfamily Ophryoscolecinae in addition to their general features of a cylindrical body, tubular vestibulum, dorsal ciliary zone considerably displaced posteriorly, well developed skeletal plates, and macronucleus beneath the right body surface. Opi. janus, Epi. ecaudatum, and Oph. purkynjei show the basic form of morphogenesis of the ciliature, similar to that in the subfamily Diplodiniinae, with four primordia developing into the oral and dorsal ciliature.