Seroprevalence of Toxoplasma gondii in mainland and sub-Antarctic New Zealand sea lion (Phocarctos hookeri) populations

AIMS: To investigate the seroprevalence of antibodies to Toxoplasma gondii in New Zealand sea lions (Phocarctos hookeri), as a potential contributor to reproductive failure.

METHODS: Archived sera were sourced from New Zealand sea lions from two recolonising mainland populations in the Otago Peninsula (n=15) and Stewart Island (n=12), as well as a declining population at Enderby Island (n=28) in the New Zealand sub-Antarctic. Sera were tested for antibodies to T. gondii using a commercially available ELISA (with samples considered positive if the sample to positive ratio was?>30%), and latex agglutination test (LAT; with titres ≥1:32 considered positive). Western blot analysis was used to validate the results of a subset of 14 samples.

RESULTS: Five samples from sea lions in mainland locations were confirmed positive for antibodies to T. gondii. Two adult females exhibited high LAT antibody titres (min 1:2048, max 1:4096) on both occasions when sampled 1 and 2 years apart, respectively. No animals from Enderby Island were seropositive.

CONCLUSIONS: Toxoplasma gondii infection is unlikely to be a major contributor to poor reproductive success in New Zealand sea lions. However, continued surveillance is pertinent to assess subclinical and clinical impacts of the parasite on these threatened populations. The commercial tests evaluated here, with further species-specific threshold refinement could provide a fast, inexpensive and reliable indicator of T. gondii exposure in New Zealand sea lions.     

高压水蒸气蒸馏法提取和厚朴树枝有效精油成分

为了有效利用和厚朴的树枝,在1.5、1.7、2.1 MPa等不同压力条件下,对和厚朴树枝进行高压水蒸气蒸馏以提取有效成分厚朴酚与和厚朴酚。对蒸馏液和废液进行气相色谱-质谱(GCMS)分析,并以有机溶剂提取出的厚朴酚与和厚朴酚作为全部提取量,计算厚朴酚与和厚朴酚的转移率。结果表明,1.5 MPa高压水蒸气蒸馏的精油收率为4.53%,厚朴酚与和厚朴酚的转移率分别为33.61%和30.59%。2.1 MPa高压水蒸气蒸馏的精油收率最高(9.05%),但是厚朴酚与和厚朴酚的转移率比1.5 MPa条件下的转移率降低。在高温高压条件下,短时间内从和厚朴树枝中得到了高提取率的厚朴酚与和厚朴酚。和厚朴的蒸馏压力越高,各成分的提取率越高,但随着压力的增加,提取成分有可能发生化学变化。     

2株广西鹅源基因XII型新城疫病毒的病原学分析

【目的】深入了解2株广西鹅源基因XII型新城疫病毒(NDV)的病原学特征,为NDV流行分布的系统监测和新城疫(ND)的科学防控提供参考依据。【方法】对2株广西鹅源基因XII型NDV(Goose/China/GX02/2018和Goose/China/GX17/2018)进行病毒噬斑纯化,通过致死鸡胚平均死亡时间(MDT)和脑内接种致病指数(ICPI)试验确定其致病性,分析F蛋白和HN蛋白氨基酸序列与参考毒株的差异位点,并基于F基因全长进行遗传进化分析。【结果】经过DF-1细胞4个代次噬斑纯化可获得2株分离株的纯化株,对应的MDT分别为54和48 h,ICPI均为1.65。2株分离株的基因组长度均为15192 nt,其3’端引导序列为55 nt,5’端尾随序列为114 nt;基于F基因核苷酸序列相似性构建的基因XII型NDV系统发育进化树显示,2株分离株(Goose/China/GX02/2018和Goose/China/GX17/2018)均属于基因XIIb亚型,与我国广东分离株属于同一基因亚型,且我国2010年的分离株、2011年的分离株及2017年后的分离株分别形成3个小分支。2株...     

Evaluation of the side-effects and thermal antinociceptive effects of intravenous hydromorphone in cats

Hydromorphone (H) may be an effective analgesic agent in cats, but fear of negative behavioral side‐effects associated with opioids is cited as a reason for avoiding this class of analgesics in cats. This study was designed to assess onset and duration of antinociception using an established feline thermal threshold model in cats, given an accepted clinical dose of 0.1 mg kg^?1 of H. In addition, cats were observed for changes in behavior and other side‐effects. Six adult cats from an established colony (four spayed females and two castrated males, 4.7–7.0 kg) received 0.1 mg kg^?1 H IV following establishment of baseline thermal threshold (TT) values. TT was tested at 15 minutes post‐injection, then at every 30–60 minutes for 12 hours. Side‐effects and behavior changes were recorded for 12 hours. Changes in TT over time were analyzed using a one‐way anova ; a p‐value <0.05 was considered significant. TT increased from a pre‐treatment value of (mean ± SD) 40.9 ± 1.65 °C to instrument cutout (55.5 °C) within 30 minutes for 5/6 cats. Mean TT was significantly elevated above baseline from 15 to 450 minutes after treatment. There was a significant increase in skin temperature from 15 to 300 minutes with peak increase of 1.55 °C at 135 minutes. Side‐effects included mydriasis (6/6) and nausea (4/6), characterized by licking, foaming, and gagging. Mydriasis occurred within 10–30 seconds of injection and persisted for 5–7 hours. Nausea was noted within 2 minutes of injection and persisted for 30–90 minutes; no vomiting occurred. Commonly observed behavioral changes included ventral tail curl (6/6 cats, onset 5–45 minutes, duration 4–5 hours) and euphoria (5/6 cats, onset <6 minutes for 4/6, duration 1–6 hours). 2/6 cats were profoundly sedate. Three cats showed signs of dysphoria with or without increased motor activity with variable onset and duration. Dysphoric behavior included staring, pacing, vocalizing, and sudden movements. 3/6 cats exhibited both euphoria and dysphoria at different times during the study. At no time were cats difficult to restrain or work with. Return to baseline behavior occurred 7–8.5 hours post‐injection. Mydriasis did not correlate closely with antinociception. Signs of sedation and euphoria corresponded with onset of antinociception, but not duration. Tail curl signs correlated with antinociception. In this model, H proved to be a rapid acting, potent, analgesic with a long (7.5 hours) duration of action. The most common behavioral changes noted were ventral tail curl, euphoria, and sedation. Mydriasis and nausea were noted as side‐effects.     

白狐源星状病毒RdRp基因的鉴定及遗传演化分析

目的 探究广州动物园一例死亡白狐Alopex lagopus肾脏中鉴定出的星状病毒的遗传变异情况。方法 对死亡白狐进行剖检,利用半巢式RT-PCR对内脏器官进行病原学检测,对扩增出的病毒株的RdRp基因序列进行相似性分析。结果 死亡白狐的肾脏苍白肿大,被膜难以剥离,肾脏中检测出的星状病毒RdRp基因呈阳性。RdRp基因与9株参考毒株的核苷酸相似性为67.5%～96.2%,其中与香港猫源星状病毒1637F的核苷酸相似性(96.2%)最高。结论 本研究为星状病毒在野生哺乳动物间的跨种传播及肠外器官中的感染提供了依据。     

Evaluation of Cluster Bean Meal Cyamposis fefrugonoloba as a Dietary Protein Source for Common Carp Cyprinus carpio L.

Abstract— A12-wk feeding experiment was conducted to study the feasibility of utilizing cluster bean seed meal (CBM) as a replacement for fishmeal in the diets for common carp Cyprnus carpio fingerlings. The replacement levels of cluster bean meal protein in the diets were 25, 50, 75, and 100% of the total fishmeal protein. All diets were isonitrogenous at 33.1% crude protein and isocaloric at 4.8 Kcal/g. There were significant differences in the final individual weights, weight gains, specific growth rates (SGR %/d), feed conversion ratios (FCR), feed efficiency ratio (FER), protein efficiency ratios (PER), and feed intake among fish group ( P × 0.05). Common carp fed the diet containing 50% (CBM) exhibited comparable growth to those fed a fishmeal-based diet. Digestibility of protein, energy and lipid decreased with increasing levels of CBM above 50% of total fishmeal replacement in the diet. Incorporation of CBM in diets significantly affected the dry matter, protein, and energy of whole fish body. These results suggest that CBM can replace 50% of the fishmeal in diet for common carp.     

额济纳胡杨林土壤含水量时空变化的研究

使用管状土壤水分仪,对额济纳胡杨林、沙枣林、柽柳林以及其它不同样地的土壤含水量时空变化进行了调查研究。结果表明,大部分样地有大约20CM的干沙层,使表层土壤含水量最低;土壤剖面的30~150CM土层内,随土壤深度的增加,土壤含水量逐渐增大;沙枣林和柽柳林的土壤含水量明显高于胡杨林土壤含水量;土壤质地的变化和三种林型耗水量的差异是土壤含水量高低变化的原因;2004年5月份的土壤含水量明显高于2003年7月份的土壤含水量。