Evaluation of truncated LipL32 expressed by Escherichia coli and Pichia pastoris for serodiagnosis of Leptospira infection in rodents

The applicability of the recombinant LipL32 for serodiagnosis of leptospiral infection in field rodents was assessed in this study. An immunodominant region of LipL32 was determined by monoclonal antibodies, and then, truncated LipL32 (tLipL32) was designed to contain the region (87–188th amino acid). The tLipL32 was compared between two recombinant expression hosts Escherichia coli and Pichia pastoris in ELISA. With field rat sera, tLipL32 expressed by P. pastoris (tLipL32p) had high antigenicity without background reactions, while tLipL32 expressed by E. coli (tLipL32e) showed high background reactions, which were reduced by pre-adsorption of sera with E. coli. To evaluate tLipL32-ELISA, field rat sera were tentatively divided into a Leptospira infection positive (12 sera) and a negative group (12 sera) based on the results from flaB gene PCR of kidney samples and WB with whole Leptospira cell. Consequently, the sensitivity of tLipL32p-ELISA for field rat sera was 83% . A similar result was obtained from tLipL32e-ELISA with adsorbed sera, (92%). However, sensitivity of tLipL32e-ELISA using sera without an adsorption treatment was 50%. Regardless of the expression host, tLipL32-ELISA had 100% specificity and sensitivity in experimentally infected laboratory rats. These results suggest that recombinant LipL32 expressed by P. pastoris is more applicable for serodiagnosis in field rats due to a lack of background reaction.     

Role of social structure in establishment of an invasive large mammal after translocation

Background

Data on the movement behavior of translocated wild pigs is needed to develop appropriate response strategies for containing and eliminating new source populations following translocation events. We conducted experimental trials to compare the home range establishment and space-use metrics, including the number of days and distance traveled before becoming range residents, for wild pigs translocated with their social group and individually.

Results

We found wild pigs translocated with their social group made less extensive movements away from the release location and established a stable home range ~5 days faster than those translocated individually. We also examined how habitat quality impacted the home range sizes of translocated wild pigs and found wild pigs maintained larger ranges in areas with higher proportion of low-quality habitat.

Conclusion

Collectively, our findings suggest translocations of invasive wild pigs have a greater probability of establishing a viable population near the release site when habitat quality is high and when released with members of their social unit compared to individuals moved independent of their social group or to low-quality habitat. However, all wild pigs translocated in our study made extensive movements from their release location, highlighting the potential for single translocation events of either individuals or groups to have far-reaching consequences within a much broader landscape beyond the location where they are released. These results highlight the challenges associated with containing populations in areas where illegal introduction of wild pigs occurs, and the need for rapid response once releases are identified. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

不同强度温度刺激对棉花黄萎病的影响

采用三个不同抗性的棉花品种、三个不同的黄萎病菌系和三个温度梯度,完全随机区组设计,在人工气候箱中研究刺激不同时间对棉花黄萎病发病的影响。结果表明,刺激温度的高低和品种的抗性对棉花黄萎病的发生与扩展有显著的影响,而菌系致病力以及刺激时间长短对棉花黄萎病的发生也存在显著差异,但影响较小;品种的抗病性对棉花黄萎病的发生起着至关重要的制约作用;温度对黄萎病的发生与扩展起着关键作用。初步明确了影响棉花黄萎病发生与扩展的几个因子间的互作效应及其影响程度。     

金针菇杂交菌株的同工酶标记与菌株特性

采用垂直平板板聚丙烯酰胺凝胶电泳（ＰＡＧＥ）法，利用酯酶同工酶谱和可溶性蛋白ＰＡＧＥ表型的差异，对金针菇的杂交后代作了遗传分析和鉴定。结果表明，金针菇杂交亲本及其后代抽工酶箐型表现明显的多型性。４个杂交菌株的同工酶亲本有较明显的差异。２处生化（ＥＳＴ，ＰＲＯ）标记在杂交菌株中均表现有不同程度的遗传互补性，并有新的酶带产生。结合同工酶酶谱和标记杂合位点数目对杂种优势可进行早期预测和栽培验证。     

农抗SH—62产生菌原生质体再生菌株的筛选和再生菌株R-4发酵规律的初步研究

本文报道了农抗SH—62产生菌原生质体再生菌株的筛选和再生菌株R—4的发酵规律。试验表明,通过摇瓶的初筛和复筛,从活性比出发菌株要强的202株再生菌株中,找出R—4、R—66和R—72三株活性最强而又稳定的再生菌株。在再生菌株R—4的发酵试验中,选出了该菌株的最佳发酵培养基为1号培养基,并证明这个菌株对溶氧量并不敏感,在偏碱条件下有利于生长和产素,发酵周期为72小时等最适发酵条件。     

上海地区野鸟中伯氏疏螺旋体和西尼罗病毒感染的血清学调查

于2005年从飞抵上海的12种候鸟和4种留鸟中采集208份血清样品,采用酶联荧光测定(ELFA)法和酶联免疫吸附试验(ELISA),分别对伯氏疏螺旋体和西尼罗病毒的感染状况进行了血清抗体调查,结果受检野鸟样品的检测结果均为阴性。     

罗平万峰山市级自然保护区保护价值评价

万峰山自然保护区地处地貌发育典型的喀斯特地区,是我国滇东喀斯特山地森林的重要组成部分,也是滇东地区重要的物种基因库。本文在对保护区内现有野生动植物资源进行分析的基础上,从典型性、稀有性、脆弱性、多样性、感染力、面积适宜性、潜在价值、科研价值等方面对保护区的保护价值进行了综合评价分析,认为保护区形成了具有代表性的喀斯特山地森林生态系统,区内的森林生态系统对保护喀斯特地区极其脆弱的生态环境及保护生物多样性具有十分重要的意义。     

盐胁迫下2种樱桃叶片解剖结构的变化

为了筛选耐盐樱桃砧木,用于天津市周边轻度盐碱地区栽培,本试验通过徒手切片的方法,研究了两种樱桃砧木在盐胁迫下的叶片解剖结构变化。结果表明：在盐胁迫下,四川樱桃的叶片增厚了3.99%,大青叶的减少了2.68%;大青叶的表皮层细胞增厚了23.6%,四川樱桃的减少了3.84%;大青叶的角质层增厚3.57%,四川樱桃的减少了18.31%;四川樱桃的栅栏组织层变化不大,大青叶的减少了16.42%;四川樱桃的海绵组织层增厚了31.96%,大青叶的增厚了21.27%;四川樱桃的栅栏组织和海绵组织层厚度的比值变小、减少了29.17%,大青叶的减少了20.80%。盐胁迫使大青叶叶片表皮细胞层变厚,角质层加厚,栅栏组织层变薄,海绵组织层加厚,整个叶片变薄。盐胁迫使四川樱桃表皮细胞层变薄,角质层变薄,海绵组织层加厚,整个叶片变厚。从盐胁迫下的2种樱桃叶片结构的变化综合分析认为大青叶的耐盐性明显高于四川樱桃。     

油茶籽提取废液中乳酸菌的分离鉴定与发酵性能

从自然发酵的油茶籽提取废液中发现1种产乳酸的细菌.以一定时间内产乳酸量的多少和耐酸性强弱为指标,经分离纯化、鉴定后初步确定为乳酸杆菌属微小乳杆菌种变种.采用接种量3%,发酵时间48h,发酵温度38℃的发酵条件测试此菌种的发酵产酸量及活菌数,其48h产酸量可达2.02%,生长稳定期活菌密度达1011cfu/mL,为具有工业利用价值的优良乳酸菌种.