Host cellular components adhering to the tegument of schistosomes from cattle, buffalo, hippopotamus and lechwe

The teguments of adult Schistosoma mattheei from cattle and buffalo, S. hippopotami from hippopotamus and S. margrebowiei from lechwe were examined by means of scanning electron microscopy for cells possibly engaged in immunological action. Leukocytes were observed on the teguments of the schistosomes from all 4 host species. Although certain of these cells seemed to be fused to the surface membrane of the worms, they did not display pseudopodia. The tegument of certain schistosomes from buffalo exhibited cells the size of platelets with dendritic structures connected to the tegument of the parasite. The results seem to indicate that, as with laboratory hosts, naturally infected domestic and wild hosts are unable to mount an effective cellular response against the tegument of live adult shistosomes. The possible role of platelets in immunology against schistosomes is mentioned.     

Hepatic and renal concentrations of copper and other trace elements in hippopotami (Hippopotamus amphibius L) living in and adjacent to the Kafue and Luangwa Rivers in Zambia

Hepatic and renal concentrations of the elements arsenic, cadmium, cobalt, copper, lead, manganese, mercury, molybdenum, selenium and zinc were studied in samples collected from hippopotami from the Kafue River in the Kafue National Park and the Luangwa River in the Southern Luangwa National Park in Zambia. There were no significant differences between trace element concentrations in the tissues of the hippopotami taken in the Kafue River and the Luangwa River. The concentrations of copper and other essential elements were similar to those reported in normal domestic and wild ruminants. Judging by the results obtained in this study, pollution from the mining activity around the Kafue River drainage area in the Copperbelt region has not led to any accumulation of elements in tissues of the hippopotami in the Kafue National Park. The trace element concentrations observed may serve as reference for similar future studies on hippopotami.     

Pesticide residues in adipose tissue from hippopotami (Hippopotamus amphibius L) living in and adjacent to the Luangwa River in Zambia

The concentration of organochlorines (OCs) such as organochlorine pesticides and polychlorinated biphenyls were measured in adipose tissue collected from 14 male hippopotami at Mfuwe in the southern part of the Luangwa National Park, Zambia. The samples contained low levels of OCs, and the concentrations of OCs were comparable to or lower than reported for wild herbivores studied in other parts of the world.     

Medetomidine-ketamine-isoflurane anaesthesia in pygmy hippopotami (Choeropsis liberiensis)--a case series

History Medical knowledge of pygmy hippopotami is limited. Anaesthesia has been considered a challenge because of the anatomy, semi‐aquatic life style and aggressive behaviour. Polycystic kidney disease (PKD) has been described and can contribute to active kidney disease potentially affecting anaesthesia. Physical examination and Management Fourteen pygmy hippopotami were anaesthetized for general health assessment and reproductive procedures. Animals (estimated bodyweight 250 kg) were darted intramuscularly with 0.08 mg kg^?1 medetomidine and 1.2 mg kg^?1 ketamine. After endotracheal intubation, anaesthesia was maintained with isoflurane delivered either by circle system (100% oxygen) or by Triservice apparatus (air or air/oxygen admixture). Heart rate (HR) respiratory rate (f_R), oxygen saturation (SpO₂) and end tidal CO₂ were recorded at 5‐minute intervals. Atipamezole was administered intramuscularly (0.4 mg kg^?1) at the end of the procedure. Statistical analysis was performed using anova (p < 0.05). Most animals rapidly became recumbent although five hippopotami needed additional drugs to assure acceptable immobilization. There were no statistical differences in mean HR between animals with or without PKD (PKD: 34 ± 8 beats minutes^?1; no PKD: 33 ± 6 beats minutes^?1), f_R (PKD: 15 ± 7 breaths minutes^?1; no PKD; 12 ± 5 breaths minutes^?1) and end tidal CO₂ (PKD: 7.1 ± 1.3 kPa; no PKD: 7.8 ± 1.4 kPa). SpO₂ was higher in animals receiving 100% oxygen or air with oxygen (92 ± 8% and 91 ± 9% respectively) compared with animals receiving air only (77 ± 5%) (p = 0.003). Recovery was uneventful after atipamezole administration. Follow‐up There were no apparent adverse effects after anaesthesia during a 24‐hour follow‐up period. Discussion and conclusions Medetomidine‐ketamine‐isoflurane induced satisfactory anaesthesia in this species. Incremental induction doses were related to remote injection and the animals’ thick skin. There were no differences in anaesthetic parameters in animals with or without PKD. Supplemental oxygen should be mandatory during anaesthesia in this species.     

Characterisation of monoclonal antibodies against a fimbrial structure of Salmonella enteritidis and certain other serogroup D salmonellae and their application as serotyping reagents

A panel of 13 monoclonal antibodies from different hybridomas was produced against a novel salmonella fimbrial antigen expressed predominantly by Salmonella enteritidis strains. The specificity of the monoclonal antibodies to this antigen (SEF14) was confirmed by enzyme-linked immunosorbent assay (ELISA) using purified SEF14, immune electron microscopy and, with 11 monoclonal antibodies, the identification of a repeating protein subunit (14,300kDa) on the antigen. Blocking-ELISA with the monoclonal antibodies identified epitopes in at least three, non-overlapping clusters which appeared evenly distributed on SEF14 in immune electron microscopy. The use of the monoclonal antibodies in direct-binding ELISA on a range of salmonella serotypes suggested that the epitopes on SEF14 are highly conserved and were expressed by all the S enteritidis strains examined; some strains of S dublin and the only strain of S moscow available were the only other serotypes that expressed SEF14. A latex agglutination reagent based on a monoclonal antibody was developed and used to test for SEF14 on 280 strains (representing 120 serotypes in 24 serogroups of salmonellae) that had been grown on Sensitest agar for 18 hours at 37 degrees C. All S enteritidis strains (64) and most S dublin strains (28 of 33) produced SEF14 as did the two strains representing S blegdam and S moscow. SEF14 was not detected in any other strains of serotypes from serogroup D or from any other serogroup examined.     

The isolation ofTrypanosoma brucei fromHippopotamus amphibius in the luangwa valley,Zambia

Summary Trypanosoma brucei was isolated from four out of75 hippopotami by means of intraperitoneal mouse inoculations. This appears to be the first isolation of trypanosomes fromHippopotamus amphibius and a new host record forT. brucei. The four strains of polymorphic trypanosomes isolated were identified asT. brucei by the blood incubation infectivity test. In500 wet and390 dry blood films (total890) of370 hippopotami examined no trypanosome was found. The value of blood film examination for the diagnosis of trypanosome infections in hippopotami is shown to be limited.

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Sumario ElTrypanosoma brucei fue aislado en cuatro de 75 hipopotamos por medio de la inoculación intraperitoneal en ratones. Este parece ser el primer aislamiento de trypanosomas deHippopotamus amphibius y un nuevo hospedero para el record delT. brucei. Las cuatro cepas de trypanosomas polimórficos aisladas fuereon identificadas comoT. brucei por la prueba de infectividad de incubación de sangre (PIIS). En 500 frotices mojados de sangre y en 390 frotices secos (890 en total) de 370 hipopotamos examinados no se encontraron trypanosomas. El valor del examen del frotiz de sangre para el diagnóstico de las infecciones por trypanosomas en hipopotamos es demostrado ser limitado.

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Résumé Trypanosoma brucei a été isolé de quatre hippopotames sur 75, par inoculation à la souris par voie intrapéritonéale. Il semble que ce soit la première fois que des trypanosomes ont été isolés d’Hippopotamus amphibius et qu’ils s’agisse d’un nouvel h?te pourT. brucei. Les quatre souches de trypanosomes polymorphes isolés ont été identifiées commeT. brucei par le test d’infectiosité du sang incubé (BIIT). Aucun trypanosome n’a été trouvé dans 890 préparations de sang (500 de sang frais et 390 frottis) de 370 hippopotames. Il a été démontré que la valeur de l’examen de frottis de sang pour le diagnostic d’infections à trypanosomes chez l’hippopotame est limitée.

     

Cytokeratin‐positive folliculo‐stellate cells in chicken adenohypophysis

Folliculo‐stellate (FS) cells are non‐endocrine cells found in the adenohypophysis and are identified in many animals by the S100 protein marker. Although keratin is another FS marker in several animals, there is no information on localization of keratin in the avian adenohypophysis. In this study, localization of cytokeratin in chicken adenohypophyseal cells was investigated immunohistochemically. Basic cytokeratin (bCK)‐positive cells were arranged radially in the cell cords with their cytoplasmic processes reaching the basal lamina. The cell bodies encircled a follicle in the center of the cell cord. Furthermore, the bCK‐positive cells were also S100B‐positive. Growth hormone, prolactin, adrenocorticotrophic hormone, and luteinizing hormone β‐subunit did not co‐localize with the bCK‐positive cells. In addition, the bCK‐positive cells had a laminin‐positive area in their cytoplasm. Transmission electron microscopy observed agranular cells equipped with several microvilli that encircled a follicle. These results indicate that bCK‐positive cells in the chicken adenohypophysis may be a predominant FS cell population and produce laminin. It is suggested that they function as sustentacular cells to sustain the adjacent endocrine cells and the structure of the cell cords in the chicken adenohypophysis.     

Sarcocystis sinensis is an ultrastructurally distinct parasite of water buffalo that can cause foodborne illness but cannot complete its life-cycle in human beings

In this study, we compared the morphology of Sarcocystis sinensis and Sarcocystis hominis, and assessed the infectiousness of S. sinensis for human volunteers. The cysts of S. sinensis were from water buffalo (Bubalus bubalis) and those of S. hominis were from cattle (Bos taurus). Transmission electron microscopy of S. sinensis cysts revealed that the cyst wall had leaning, finger-like protrusions measuring 1.44-5.08 μm in length and without invaginations on the tip surface of the protrusions. In contrast, the cyst wall of S. hominis had upright, finger-like protrusions measuring 9.43 μm×2.42 μm and with vesicle-like invaginations on the tip surface of the protrusions. Scanning electron microscopy revealed that surface of the protrusions was arranged as rectangles in S. sinensis, as compared to tongue-shaped in S. hominis. Other distinguishing features of S. sinensis include a thin ground substrate (GS) zone with microtubules and small, circle-like structures located at the base of the protrusions. Human volunteers, after consuming S. sinensis cysts, produced no sporocysts or oocysts in feces, suggesting that humans could not serve as definitive hosts for S. sinensis. By contrast, many sporocysts and oocysts were passed in feces of a human volunteer 11-29 days after ingestion of S. hominis cysts. These results showed that S. sinensis and S. hominis are separate species and S. sinensis cannot use human being as the definitive host.     

Acute anaplasmosis in imported cattle

Of 18 Hereford cattle imported into Quebec from the eastern U.S.A., five exhibited acute hemolytic anemia, icterus, depression, fever, anorexia and died; 11 were killed because they had positive or suspicious anaplasma titers and two were quarantined. Anaplasma marginale organisms were found in the erythrocytes of the sick animals by light and electron microscopy. The partial absence of erythrocytic plasmalemma on several electron photomicrographs suggested exit of the anaplasma bodies. Titers up to 1:320 in infected animals were found by the complement fixation test.     

The prevalence and identity of Sarcocystis in beef cattle in New Zealand

Muscle tissue from the oesophagus and diaphragm of 500 beef cattle slaughtered in New Zealand was examined for Sarcocystis infection by microscopic examination of cysts isolated from muscle samples. All cattle were infected with Sarcocystis; based on light microscopy of cysts, 98% had thin-walled Sarcocystis cruzi cysts and 79.8% had thick-walled (Sarcocystis hirsuta/Sarcocystis hominis) cysts. Cysts were also collected for electron microscopy and transmission experiments. Thick-walled cysts could not be distinguished as S. hirsuta or S. hominis by light or electron microscopy. Thick-walled cysts were fed to three cats and one human volunteer; one cat shed sporocysts but not the human volunteer. Electron microscopy of the cysts revealed many features that have not been described previously.     

Elucidation of the neurological effects of clothianidin exposure at the no-observed-adverse-effect level (NOAEL) using two-photon microscopy in vivo imaging

Neonicotinoid pesticides (NNs) cause behavioral abnormalities in mammals, raising concerns about their effects on neural circuit activity. We herein examined the neurological effects of the NN clothianidin (CLO) by in vivo Ca²⁺ imaging using two-photon microscopy. Mice were fed the no-observed-adverse-effect-level (NOAEL) dose of CLO for 2 weeks and their neuronal activity in the primary somatosensory cortex (S1) was observed weekly for 2 weeks. CLO exposure caused a sustained influx of Ca²⁺ in neurons in the S1 2/3 layers, indicating hyperactivation of neurons. In addition, microarray gene expression analysis suggested the induction of neuroinflammation and changes in synaptic activity. These results demonstrate that exposure to the NOAEL dose of CLO can overactivate neurons and disrupt neuronal homeostasis.     

Detection of bovine coronavirus and type A rotavirus in neonatal calf diarrhea and winter dysentery of cattle in Quebec: evaluation of three diagnostic methods.

The use of direct electron microscopy, enzyme-linked immunosorbent assay, and protein A-gold immunoelectron microscopy for the identification of bovine coronavirus and type A rotavirus were examined. Two hundred and forty-nine samples from diarrheic calves and winter dysenteric cattle from seven geographic areas in Quebec were examined for the presence of viruses by direct electron microscopy of negatively stained preparations. In addition, all the samples were analyzed by enzyme-linked immunosorbent assay, and a random selection of 47 samples were also analyzed by protein A-gold immunoelectron microscopy. Thirty-nine percent of samples examined by direct electron microscopy contained viral particles; bovine coronavirus and type A rotavirus were the most common viruses involved. Overall agreement between any two of the methods used compared favorably with results obtained by others using similar methods. The presence of coronavirus and rotavirus in fecal samples obtained from neonatal calves and the presence of coronavirus in samples from winter dysenteric adult cattle suggested their etiological roles in the respective diseases. Furthermore, results from protein A-gold immunoelectron microscopy of coronavirus-like particles implied that a different coronavirus or some other viruses might be involved in these diseases. Finally, the efficiency of direct electron microscopy, enzyme-linked immunosorbent assay and protein A-gold immunoelectron microscopy as diagnostic tools is discussed.     

Scanning electron microscopy of the teguments of males from five populations of Schistosoma mattheei

The teguments of males from 5 populations of S. mattheei, of which 3 were sympatric and 2 allopatric with S. haematobium, were studied by means of scanning electron microscopy (SEM). A certain percentage of the males of each sympatric population bore tubercle spines while the allopatric populations were spineless. It is postulated that the presence of tubercle spines is a characteristic inherited from S. haematobium.     

Subcutaneous Soft Tissue Sarcoma with Rhabdoid Features in a Dog

A nine-year-old male beagle dog had a white spherical mass in the subcutis of the left lumbar region. Microscopically, spindle to oval cells diffusely proliferated in the fibrous and myxoid stroma. Many neoplastic cells showed rhabdoid features or vacuolated cytoplasm. Immunohistochemically, the neoplastic cells were positive for vimentin and S100 and partly positive for neuron-specific enolase and glial fibrillary acidic protein but were negative for von Willebrand factor, desmin and α-smooth muscle actin. Ultrastructurally, the neoplastic cells had abundant cytoplasmic processes and desmosome-like structures. Cytoplasmic inclusions of rhabdoid-featured cells in HE sections were composed of aggregates of intermediate filaments, and cytoplasmic vacuoles were identified as an invagination of cytoplasm. Although malignant peripheral nerve sheath tumor was suggested according to these results, the present case was diagnosed as a soft tissue sarcoma with rhabdoid features due to a lack of identification of the basal lamina under electron microscopy.     

Isolation of Staphylococcus simulans from dermatitis in a captive African pygmy hedgehog

Staphylococcus simulans, a coagulase-negative staphylococcal species, can cause several diseases in humans and animals. This report describes a case of dermatosis characterized by broad, well-circumscribed hyperkeratosis and alopecia on the back of a household pygmy hedgehog (Erinaceous albiventris). Quills and exudates were studied by microscopy. The microscopic examination of the exudates collected from the lesion revealed several leukocytes and numerous gram-positive cocci. An aerobic bacterial culture revealed overgrowth of the same gram-positive bacteria. The bacterium was identified as S. simulans by polymerase chain reaction amplification and direct sequencing targeted to the 16S ribosomal RNA gene. This report is the first to show that S. simulans could be related to the dermatitis of hedgehogs.     

Toxoplasmosis in Indo-Pacific humpbacked dolphins (Sousa chinensis), from Queensland

OBJECTIVE: To describe the clinical signs, gross pathology, serology, bacteriology, histopathology, electron microscopy and immunohistochemistry findings associated with toxoplasmosis in four Indo-Pacific humpbacked dolphins (Sousa chinensis) that stranded in Queensland in 2000 and 2001. DESIGN: Clinical assessment, gross necropsy, and laboratory examinations. PROCEDURE: Necropsies were performed on four S. chinensis to determine cause of death. Laboratory tests including serology, bacteriology, histopathology and transmission electron microscopy were done on the four dolphins. Immunohistochemistry was done on the brain, heart, liver, lung, spleen and adrenal gland from various dolphins to detect Toxoplasma gondii antigens. RESULTS: Necropsies showed all of four S. chinensis that stranded in Queensland in 2000 and 2001 had evidence of predatory shark attack and three were extremely emaciated. Histopathological examinations showed all four dolphins had toxoplasmosis with tissue cysts resembling T. gondii in the brain. Tachyzoite stages of T. gondii were detected in the lungs, heart, liver, spleen and adrenal gland, variously of all four dolphins. Electron microscopy studies and immunohistochemistry confirmed the tissues cysts were those of T. gondii. All four dolphins also had intercurrent disease including pneumonia, three had peritonitis and one had pancreatitis. CONCLUSION: Four S. chinensis necropsied in Queensland in 2000 and 2001 were found to be infected with toxoplasmosis. It is uncertain how these dolphins became infected and further studies are needed to determine how S. chinensis acquire toxoplasmosis. All four dolphins stranded after periods of heavy rainfall, and coastal freshwater runoff may be a risk factor for T. gondii infection in S. chinensis. This disease should be of concern to wildlife managers since S. chinensis is a rare species and its numbers appear to be declining.     

氟对家蚕胚胎培养细胞毒害作用的形态学和组织学研究

用扫描电镜和透射电镜对氟中毒的家蚕胚胎培养细胞（ＢｍＮ４细胞株）进行了超微形态和组织学研究。结果中毒细胞的细胞膜、内质网、线粒体均严重损伤。氟中毒影响了细胞生物膜的透性和细胞呼吸体系。     

Phenotypic differences in Schistosoma mattheei ova from populations sympatric and allopatric to S. haematobium

Schistosoma mattheei ova were collected from cattle in different localities in South Africa and after hatching, miracidia were used to infest Bulinus (Physopsis) globosus. Cercariae harvested from these snails were used to infest the definitive host Praomys (Mastomys) coucha and eggs from the resulting female S. mattheei were collected. These ova were compared with a Schistosoma haematobium X S. mattheei hybrid similarly collected from an infested P. (M.) coucha. The results indicate that S. mattheei populations which are sympatric to S. haematobium possess S. haematobium characteristics. It is suggested that the gene pools of populations of the parasite in these areas are infiltrated with S. haematobium genes via the S. mattheei X S. haematobium hybrid originating from human hosts.     

狂犬病病毒抗原的形态学定位

利用免疫胶体金标记技术,对感染BHK—21细胞的鹿狂犬病病毒抗原进行了形态学定位.透射电镜观察,发现病毒粒子囊膜表面的圆端和侧面以及核衣壳均被免疫金颗粒所标记,囊膜平齐端无免疫金颗粒附着.病毒感染细胞时,以其圆端和侧面吸附于宿主细胞膜.据此从形态学角度证明,成熟病毒粒子抗原存在于核衣壳以及囊膜的圆端和侧表面,囊膜平齐端无病毒抗原.