RAW TROPICAL OYSTERS AS VEHICLES FOR MULTIDRUG-RESISTANT Vibrio parahaemolyticus

The following study aimed to determine the antimicrobial susceptibility profile of Vibrio parahaemolyticus strains from fresh and frozen oysters Crassostrea rhizophorae sold in Fortaleza-Brazil. An antibiogram was performed on 87 isolates using nine antibiotics: gentamicin (Gen 10 µg), ampicillin (Amp 10 µg), penicillin G (Pen 10U), ciprofloxacin (Cip 5 µg), chloramphenicol (Chl 30 µg), nalidixic acid (Nal 30 µg), tetracycline (Tet 30 µg), vancomycin (Van 30 µg) and erythromycin (Ery 15 µg). All strains were resistant to at least one antibiotic, and 85 (97.7%) were multi-resistant, with predominance of the Van+ Pen+Amp resistance profile (n = 46). Plasmid resistance to Pen, Amp and Ery was detected. Thus, the risk that raw oyster consumption poses to the health of consumers is highlighted, due to the fact that these bivalves may host antibacterial-resistant microorganisms.     

Reduction in Virulence over Time in Ostreid herpesvirus 1 (OsHV-1) Microvariants between 2011 and 2015 in Australia

Microvariant genotypes of Ostreid herpesvirus 1 (OsHV-1) are associated with mass mortality events of Pacific oysters in many countries. The OsHV-1 microvariant (µVar) emerged in France 2008 and caused significant economic losses as it became endemic and displaced the previously dominant OsHV-1 reference genotype. Recently, considerable genotypic variation has been described for OsHV-1 microvariants, however, less is known about variation in viral phenotype. This study used an in vivo laboratory infection model to assess differences in total cumulative mortality, peak viral load, transmissibility, and dose-response for three OsHV-1 isolates obtained between 2011 and 2015 from endemic waterways in Australia. This followed field observations of apparent reductions in the severity of mass mortalities over this time. Significantly higher hazard of death and cumulative mortality were observed for an isolate obtained in 2011 compared to isolates from 2014–2015. In keeping with other studies, the hazard of death was higher in oysters challenged by injection compared to challenge by cohabitation and the mortality was higher when the initial dose was 1 × 10⁴ OsHV-1 DNA copies per oyster injection compared to 1 × 10² DNA copies. There was no difference in the quantity of OsHV-1 DNA at time of death that could be related to isolate or dose, suggesting similar pathogenetic processes in the individual oysters that succumbed to end-stage disease. While the isolates examined in this study were biased towards pathogenic types of OsHV-1, as they were collected during disease outbreaks, the variation in virulence that was observed, when combined with prior data on subclinical infections, suggests that surveillance for low virulence genotypes of OsHV-1 would be rewarding. This may lead to new approaches to disease management which utilize controlled exposure to attenuated strains of OsHV-1.     

粗江蓠多糖对辐射损伤小鼠NK细胞的影响

目的：研究粗江蓠多糖（Gracilaria Gigas Harvey Polysaccharides,GHPS）对辐射损伤小鼠NK细胞的影响。方法：采用60Coγ射线5Gy全身照射小鼠制造辐射损伤模型,通过乳酸脱氢酶释放法检测不同剂量（10mg/kg,20mg/kg,40mg/kg）的GHPS对辐射损伤小鼠NK细胞杀伤靶细胞能力的影响。结果：辐射对照组小鼠接受60Coγ射线5Gy照射后,NK细胞的活性显著低于正常对照组（P〈0.01）。经腹腔注射（10、20、40）mg/kg GHPS,再接受γ射线5Gy照射后,小鼠NK细胞活性明显高于辐射对照组（P〈0.01）,并有剂量依赖性。结论：5Gyγ射线可以抑制小鼠NK细胞杀伤靶细胞的活性,而GHPS对辐射损伤小鼠的NK细胞有保护作用。     

Insulin-like system and growth regulation in the Pacific oyster Crassostrea gigas: hrIGF-1 effect on protein synthesis of mantle edge cells and expression of an homologous insulin receptor-related receptor

The involvement of molecules belonging to the insulin/IGF family in regulation of growth has been investigated in the Pacific oyster Crassostrea gigas. In vitro biological effects of human recombinant IGF-1 (hrIGF-1) on mantle edge cells, involved in oyster shell and soft body growth, were studied over an annual cycle. In mantle edge cells hrIGF-1 stimulates protein synthesis of 56+/-5.1% over basal for 10(-10) M in September with in addition a clear dose-effect corresponding to the highest shell growth period, and 57.5+/-3.45% over basal for 10(-11) M in March and 51+/-5.4% over basal for 10(-10) M in April corresponding to the period of mantle growth. These insulin-like effects were associated with the expression of a recently identified C. gigas insulin receptor-related receptor (CIR) in mantle edge cells as demonstrated by RT-PCR. Moreover, in situ hybridisation (ISH) confirmed this expression at the level of the inner and outer epithelia involved in mantle growth and shell formation.     

Primary culture of Pacific oyster,Crassostrea gigas,heart cells

Summary Pacific oyster,Crassostrea gigas, is the most economically important specie to the world shellfish breeding. It is important to note that infectious diseases, particularly viruses, may be hazardous for theC. gigas live-stocks. The study of these viral diseases and the development of diagnosis method need the establishment of in vitro methods for viral multiplication. As no oyster cell line is available actually, we have developed a procedure for primary culture of heart cells which could enable to study molluscan viruses in vitro, and could also provide a diagnosis method based on the search of eventual cytopathogen viral effects. Cells fromC. gigas ventricle of heart were dissociated by trypsin-EDTA treatment and the mechanical action of a Dounce type homogeneizer. The cells were inoculated in previously poly-D-lysin coated flasks. The optimised culture medium was L-15 (Leibovitz) prepared three fold concentrated, then diluted half with sea water, this mixture was supplemented with 10% FCS and 5%C. gigas hemolymph. Different cell types could be identified by transmission electron microscopy analysis, as mostly cardiomyocytes, fibroblast-like cells and pigmented cells, but also haemocytes were present in the cultures.     

The effect of herbal extract (EstroG-100) on pre-, peri- and post-menopausal women: a randomized double-blind, placebo-controlled study

This clinical research study was designed to evaluate the efficacy of a new herbal product, EstroG-100, containing a mixture of standardized extracts of Cynanchum wilfordii, Phlomis umbrosa and Angelica gigas, on menopausal symptoms. This randomized double-blind, placebo-controlled trial was performed for 12 weeks with 64 pre-, peri- and postmenopausal White Hispanic, White non-Hispanic and African American women who were randomly allocated to either the EstroG-100 group (n = 31) or the placebo group (n = 3). Primary end-points were the mean change in scores of the Kupperman menopause index (KMI) that evaluates 11 symptoms, and the mean change in scores of vaginal dryness. The mean KMI score was significantly reduced in the EstroG-100 group from 29.5 ± 7.4 at baseline to 11.3 ± 5.8 (p < 0.01) compared with change of the placebo group (29.2 ± 6.6 at baseline vs 23.7 ± 7.7 at week 12). The constituting symptoms of vasomotor, paresthesia, insomnia, nervousness, melancholia, vertigo, fatigue and rheumatic pain were significantly improved in the EstroG-100 group in comparison with the placebo group (p < 0.05). Statistically significant improvement in vaginal dryness in the EstroG-100 group was also observed compared with that of the placebo group (p < 0.05). In conclusion, EstroG-100 significantly improved the menopausal symptoms of pre-, peri- and post-menopausal women without weight gain or any serious side effects.     

福建省首例人体广州管圆线虫病疫源地的调查研究

目的以福建省首例人体广州管圆线虫病病例为线索进行本病的疫源地调查研究。方法1.捕捉患者发病前半生吃大瓶螺处的贝类及蛞蝓,检查广州管圆线虫幼虫;2.捕捉当地鼠检查广州管圆线虫;注意鼠粪中的广州管圆线虫幼虫并与粪类圆线虫等相鉴别;3.以发现的广州管圆线虫第3期幼虫感染实验大白鼠。结果 1.捕捉大瓶螺238只,检查124只,有广州管圆线虫幼虫者52只,感染率为41.94％,计数5只螺内幼虫,共发现13381条,其中最多者为8754条。检查蛞蝓3只,发现幼虫1条。2.检查褐家鼠2只,发现福氏类圆线虫幼虫1只。3.以发现的广州管圆线虫幼虫感染2只大白鼠,40天后在粪便中查出幼虫,42天后解剖,在肺与心脏检及雌、雄成虫66条及大量幼虫、虫卵。结论患者家乡——福建省闽侯县甘蔗镇三英村为广州管圆线虫病疫源地。     

Tracing cadmium contamination kinetics and pathways in oysters (Crassostrea gigas) by multiple stable Cd isotope spike experiments

Laboratory experiments using stable Cd isotopes (¹¹⁰Cd and ¹¹²Cd) were conducted to separately and simultaneously characterize Cd accumulation in different tissues of Pacific oysters (Crassostrea gigas) via the (i) trophic and (ii) direct pathways. For this, we exposed juvenile oysters to ¹¹⁰Cd-spiked seawater (¹¹⁰Cd: 2 μg l⁻¹; constant level) and ¹¹²Cd-spiked food (Thalassiossera weissflogii, ¹¹²Cd: 2 μg l⁻¹ in 35×10³ cells/oyster/L) in four experimental treatment groups, each containing 6 oysters, for 21 days with constant trophic feeding. These Cd contamination levels were ∼10 times lower than those typically used in experimental accumulation studies. Three oysters per treatment group were dissected every 7 days with separate sampling of the gills, digestive gland and the rest of the body. Metallothioneins were analysed in the digestive gland and gills. Cadmium concentrations and isotope ratios were measured in water (daily) and tissues (weekly) by GF-AAS and ICP-MS. The observed time-dependant evolution in Cd concentrations and ¹¹⁰Cd/¹¹⁴Cd and ¹¹²Cd/¹¹⁴Cd isotope ratios clearly revealed the bio-accumulation short-term kinetics and pathways of Cd contamination in the different tissues. Under the experimental conditions, significantly changed isotope ratios in gills and the digestive gland of oysters suggested rapid and efficient contamination by ¹¹⁰Cd derived from direct exposure followed by internal Cd transfer between organs. Trophic contamination became measurable after 14 days of exposure corresponding to a trophic transfer rate of 1%. Constant metallothionein levels during the experiment suggested that the initially present metallothionein levels were sufficient to deal with the experimental Cd exposure.     

Effects of salinity,heavy metals and pesticides on health and physiology of oysters in the Caloosahatchee Estuary,Florida

The Caloosahatchee Estuary has been exhibiting signs of impaired ecological health due to the extensive hydrological alteration, agricultural land use, and increasing watershed development. This project investigated the responses of the American oyster, Crassostrea virginica at five locations in the Caloosahatchee River in relation to salinity changes, levels of heavy metals, pesticides, and PCBs in the water as well as in the oyster tissue. Individual heavy metal and organochlorine pesticide concentrations in oysters varied significantly between sampling locations and sampling months. PCB concentrations in oyster tissues were below detection limits as were the metal, pesticide and PCB concentrations in water at all the sampling locations. Both heavy metal and pesticide concentrations decreased with increasing distance downstream indicating upstream source of contaminants. The highly pathogenic oyster parasite Perkinsus marinus infection intensity (level) and prevalence (% infected oysters), condition index, spat recruitment, and gonadal index showed a seasonal trend varying with spawning activity and increased downstream. However, juvenile oyster growth was higher at upstream estuarine locations. Oyster responses varied more with seasonal programming (salinity), rather than due to contaminant levels. While significant correlations were noted between some oyster responses and metal concentrations in oyster tissues, overall metal concentrations were low compared to national averages. It appears that oyster health in the Caloosahatchee River is influenced more by freshwater inflow and resulting salinity fluctuations, rather than due to the measured contaminants.     

江苏兴化牡蛎的鉴別研究

本文通过对江苏兴化古生物牡蛎介壳与福建牡蛎介壳的超微结构,红外光谱、梅根反应的分析对比,可看出古生物牡蛎其组织结构并未发出质的衍变,均为方解石(calcite)。