A latex agglutination test for the detection of Echinococcus multilocularis coproantigen in the definitive hosts

A latex agglutination test for detecting Echinococcus multilocularis coproantigen in definitive hosts was developed using latex beads sensitized with EmA9 monoclonal antibody raised against somatic antigens of adult E. multilocularis. A primary test (LA 1) was performed on 82 fecal samples of necropsied foxes, of which 46 were infected, and resulted in 61% sensitivity and 86% specificity. To increase the sensitivity, 4 ng/mL of excretory/secretory antigens of adult worms was added to the samples in a secondary test (LA 2), resulting in 91% sensitivity and 61% specificity. The positive predictive value of the LA 1 test and the negative predictive value of the LA 2 test were both 85%. The combination of the LA 1 and LA 2 tests is applicable and practical for use in situations that require quick diagnosis or screening based on the following interpretation: the samples that are positive in the LA 1 test are positive; the samples that are negative in the LA 2 test are negative; and the samples that are negative in the LA 1 test and positive in the LA 2 test are classified as suspicious.     

Effects of lectin in the scleractinian coral Ctenactis echinata on symbiotic zooxanthellae

We report herein the presence of a lectin in the scleractinian coral Ctenactis (Fungia) echinata. The lectin bound preferentially to lactose, melibiose, and d-galactose. The purified lectin CecL was composed of several isolectins, and it was found to have a molecular mass of 67.4 kDa via gel filtration. Glycopeptidase F-treated CecL showed a single band at 32.5 kDa. The mass/charge ratios of the reduced CecL peaks were equivalent to half those of the native peaks. These results suggest that CecL is composed of two glycosylated polypeptides linked by interchain disulfide bonds. In a biological activity test using a zooxanthellal culture (Dinoflagellate Symbiodinium) clonally isolated from Fungia cf. fungites, CecL transformed the flagellated motile form of Symbiodinium into the nonmotile coccoid form, a form equivalent to the symbiotic stage. The activity of CecL on Symbiodinium cells was concentration dependent, and 100 μg/ml CecL arrested Symbiodinium cells in the coccoid form for 5 days. CecL also suppressed the growth of Symbiodinium cells, unlike the octocoral lectin derived from Sinularia lochmodes, which arrests Symbiodinium cells in the coccoid form but does not affect the growth of the coccoid. This result provides further evidence that coral lectins play a role in symbiont engagement and maintenance in zooxanthellae–coral symbiosis.     

Collaborative control initiatives targeting zoonotic agents of alveolar echinococcosis in the northern hemisphere

Alveolar echinococcosis is one of the most important lethal zoonotic helminth infections in the northern hemisphere. Currently, the threat to public health is increasing, as evidenced by the rising prevalence rate of alveolar echinococcosis, as well as the invasion of urban areas by infected wild foxes. This threat is further increased due to the involvement of pet dogs, and probably cats, as emerging sources of infection. These increased threats to public health also have associated economic risks; therefore, there is a need for effective and sustainable methods of control. In this paper, initiatives to control alveolar echinococcosis by targeting its definitive hosts through anthelmintic baiting campaigns initiated by local residents who used local resources for bait production, distribution and collection of fecal samples for diagnosis are described. Further, when such distribution programs are coupled with the use of GIS-based maps, the optimum distribution of bait was obtained. These programs have also included the use of intravital diagnostic analyses of infection rates, which have been overseen by the Forum on Environment and Animals (FEA), and also allowed a nationwide monitoring of echinococcosis in difinitive hosts. In addition, a government initiative requiring mandatory reporting of echinococcosis in dogs to health authorities was recently initiated in Japan. Overall, the results of this study have shown that use of collaborative control initiatives targeting zoonotic agents of alveolar echinococcosis can be an effective method for reducing the threat of lethal echinococcosis in the northern hemisphere.     

Heat stress decreases plasma vitamin C concentration in lactating cows

Heat stress causes oxidative stress, which decreases plasma levels of vitamin C, an antioxidative vitamin in pigs and poultry. We investigated the plasma vitamin C concentration in lactating cows exposed to a hot environment temperature. In the first experiment, plasma vitamin C concentrations of 8 lactating cows were measured in summer and autumn. The concentration was found to be significantly lower in summer. The second experiment was performed using 4 lactating cows in a crossover design. The ambient temperature was set at 18 °C in the control treatment and at 28 °C in the heat-stressing treatment. Milk yields and feed intake tended to be lower in the stressing than control treatment. Rectal temperature and respiration rate were significantly (P < 0.05) higher in the heat-stressing treatment. The plasma vitamin C concentration was significantly (P < 0.05) lower in the heat-stressing period. These results indicate that heat stress decreases the plasma vitamin C concentration. Dietary supplementation with vitamin C may be beneficial for lactating cows in hot weather.     

Use of an automatic cell-counting system with LED illumination for enumeration of marine bacteria

ABSTRACT:   The concentration of aquatic bacteria is basic information required to evaluate the status of environments and to assess bacterial contribution to material cycles. However, the standard direct counting method using epifluorescence microscopy (EFM) is tedious and there is variation in the counts among workers. Here an automatic counting system that consists of Bioplorer (BP) and image analysis has been applied to marine bacteria. BP is composed of a light-emitting diode (LED) illuminant, an optical unit, a driving stage and a charge-coupled device camera. In combination with fluorescent labeling and simplified membrane filtration, bacteria are enumerated automatically. The reproducibility, sensitivity and accuracy of the system were tested for natural marine bacteria, in comparison with EFM and flow cytometry (FCM). The counts obtained by BP showed good correlation with those obtained by EFM and FCM methods. The counts were significantly higher in inshore and oceanic samples, indicating high sensitivity with low background noise. Considering its reproducibility, objectivity, ease of use and compact size, BP can be used as a routine tool for counting aquatic bacteria in substitution for EFM or FCM.     

A morphological study off a thyroid carcinoma in a medaka, Oryzias latipes (Temminck & Schlegel)

A large mass protruding beyond the left operculum was found in an adult male medaka, Oryzias latipes (Temminck & Schlegel). Histologically, the mass was mainly composed of thyroid follicles measuring up to 292 μm in diameter. The follicular epithelium consisted of cuboidal or squamous cells. The follicles lacked colloidal material in the lumen. The thyroid tissue infiltrated into the kidney. Electron microscopically, the tumour cells were characterized by dilation and vesiculation of rough endoplasmic reticulum, which extended throughout the cytoplasm, and an irregular outline of the nucleus. Mitotic figures and partly degenerate cells were frequently observed. Based on the above features, the tumour was diagnosed as a follicular carcinoma of the thyroid, the first reported case in the medaka.     

Immune response to Echinococcus multilocularis infection in the mouse model: a review.

Echinococcus multilocularis is a cestode helminth which, along with E. granulosus, E. oligarthus and E. vogeli is a causative agent of hydatid disease in man. In the intermediate host (including man), cysts formed by the metacestode (larval stage) develop in the internal organs, causing functional impairment which often leads to the death of the host. In this review larval E. multilocularis infection in mice, the most popular experimental intermediate host, is examined, and the immune response to the organism is described in detail. Evidence is presented which suggests that cell-mediated immunity (CMI) plays a large role in suppression of larval growth. Congenitally athymic nude mice, and mice treated to remove thymocytes had high susceptibility to infection, while mice strains assessed as having high helper T lymphocyte function showed resistance to infection. The degree of antibody response shown by the host does not correlate with the susceptibility to E. multilocularis. Infection with E. multilocularis is accompanied by immunosuppression, manifested by inhibition of effector cell chemotaxis and receptor expression, suppressor macrophage and lymphocyte activity, decline in helper T-lymphocyte activity and immune-complex deposition.