The food contaminant fumonisin B1 reduces the maturation of porcine CD11R1+ intestinal antigen presenting cells and antigen-specific immune responses, leading to a prolonged intestinal ETEC infection

Consumption of food or feed contaminated with fumonisin B₁ (FB₁), a mycotoxin produced by Fusarium verticillioides, can lead to disease in humans and animals. The present study was conducted to examine the effect of FB₁ intake on the intestinal immune system. Piglets were used as a target and as a model species for humans since their gastro-intestinal tract is very similar. The animals were orally exposed to a low dose of FB₁ (1 mg/kg body weight FB₁) for 10 days which did not result in clinical signs. However, when compared to non-exposed animals, FB₁-exposed animals showed a longer shedding of F4⁺ enterotoxigenic Escherichia coli (ETEC) following infection and a lower induction of the antigen-specific immune response following oral immunization. Further analyses to elucidate the mechanisms behind these observations revealed a reduced intestinal expression of IL-12p40, an impaired function of intestinal antigen presenting cells (APC), with decreased upregulation of Major Histocompatibility Complex Class II molecule (MHC-II) and reduced T cell stimulatory capacity upon stimulation. Taken together, these results indicate an FB₁-mediated reduction of in vivo APC maturation.     

青海省冬虫夏草寄主蝙蝠蛾幼虫肠道菌群变化分析

对青海全省分布的冬虫夏草寄主蝙蝠蛾幼虫、人工培养得到的幼虫,天然冬虫夏草寄生蝙蝠蛾幼虫的肠道菌群进行分离和培养,并进行对比分析实验。结果表明：从所有被检蝙蝠蛾幼虫的肠道中分离纯化出11个不同菌群,其中以葡萄菌属的数量较大,分离频率较高,为优势菌群,特别是可以确定LG03、LG04菌株是冬虫夏草寄生蝙蝠蛾幼虫肠道内的优势细菌。在人工培养的幼虫肠道内没有检出真菌,放线菌仅存在于自然采挖的冬虫夏草寄生的幼虫肠道内。     

不同季节拉脊蝠蛾幼虫肠道菌群分析

应用常规分离培养法对不同季节的拉脊蝠蛾幼虫肠道内的细菌、真菌及放线菌菌群进行分析,进一步了解拉脊蝠峨肠道菌群组成,以期发现优势菌群在不同时期的变化规律,为提高幼虫的成活率和侵染率提供基础信息。结果表明,在不同季节从80头幼虫肠液中共分离出17个不同的菌群,其中细菌11个,真菌6个,放线菌2个。     

The anatomical distribution and antimicrobial susceptibility of yeast species isolated from healthy dogs

The aim of this work was to identify the predominant yeast species present at different anatomical sites in healthy dogs and to determine their in vitro antimicrobial susceptibility using a broth microdilution assay. Samples were collected from the preputial, vaginal, oral and perianal mucosae and the isolates cultured were identified according to their morphological characteristics and biochemical profile. Malassezia pachydermatis was the most commonly isolated yeast, followed by Candida parapsilosis, Candida tropicalis, Candida albicans, Saccharomyces cerevisiae and Rhodotorula spp.Minimum inhibitory concentrations of the azole derivatives ketoconazole, itraconazole and fluconazole against Candida spp. were 0.03–16 μg/mL, 0.06 to >16 μg/mL and 0.5–64 μg/mL, respectively and Candida isolates were sensitive to caspofungin and amphotericin B. Although all isolates of M. pachydermatis were sensitive to itraconazole, fluconazole, ketoconazole and amphotericin B, they were found to be resistant to caspofungin. The study has highlighted that Candida spp., M. pachydermatis, S. cerevisiae and Rhodotorula spp. are part of the normal canine surface microbiota and some of these organisms exhibit in vitro resistance to commonly used antimicrobials.     

脂多糖应激对断奶仔猪肠黏膜免疫屏障的影响

选用12头(21±1)d断奶仔猪,随机分为2个处理,研究脂多糖(LPS)刺激对肠黏膜免疫屏障功能的影响。禁食12h后,LPS组仔猪腹膜注射100μg/kgBW LPS,对照组注射等量的生理盐水。48h后,屠宰仔猪,打开腹腔,取小肠组织样品,测定小肠上皮间淋巴细胞、杯状细胞、肥大细胞数、肠集合淋巴结增殖、凋亡细胞数。结果表明:LPS刺激显著降低十二指肠、回肠上皮间淋巴细胞数(P<0.01),极显著增加小肠各段肥大细胞数(P<0.01);LPS刺激显著增加回肠集合淋巴结凋亡细胞数(P<0.05),但对增殖细胞数没有影响(P>0.05);LPS刺激可增加仔猪小肠杯状细胞数,但两处理组间差异不显著(P>0.05)。这些结果显示,LPS应激可导致肠黏膜免疫屏障功能改变,进而加重机体出现急性感染症状。     

青藏高原东缘兰科藏药植物资源调查

通过实地调查与文献研究相结合的方法对青藏高原东缘兰科藏药植物资源进行了调查,结果表明:兰科藏药植物共有10属11种,分别占兰科植物总属数和总种数的25.64%和13.10%。可归属为5个分布型,其中北温带分布型占绝对优势,占本区总属数的60%,说明青藏高原东缘兰科藏药植物区系为温带性质。     

甘肃被子植物中国特有属研究

甘肃位于秦岭山地、黄土高原、青藏高原和蒙新高原的交接地带,气候类型多样、区系成分复杂。在甘肃被子植物区系中分布有中国特有属57个,含72种1亚种6变种,隶属于38科,其数量为黄河流域以北各省区之首。研究对廉永善等1997年所提出的甘肃中国特有类群分布区亚型划分进行了修订,对甘肃被子植物中国特有属在各分布亚型中属的数量、属型结构及所含种的数量进行了研究,并对特有类群的地理分布进行了探索。结果表明：亚热带区系成分在甘肃被子植物中国特有属中占有很重要的位置,计24属,占特有属数的42.1％。在各分布区亚型所含属种数量的统计中,华中成分和横断山成分分别位居第一和第二,是甘肃中国特有属组成的主要成员,分别为15属和13属,占26.3％和22.8％。单种属（包括单型属和甘肃仅分布1种的少型属至多型属）是甘肃中国特有属的主体,占甘肃中国特有属的82.5％。文县无疑是甘肃被子植物中国特有属及所含种的分布多度中心。     

泡桐下侧芽萌发成枝与上侧芽萌发接干间关系

该文研究了自然状态下1年生泡桐下侧芽萌发成枝与上侧芽萌发接干间的关系.结果显示:在高密度林分的接干单株中,上侧芽萌发成枝接干与下侧芽萌发成枝间关系密切.接干侧芽的对生侧芽萌发不利于接干枝高生长,并降低接干形率;接干处向下数第1对侧芽萌发成枝倾角越小接干形率越高,第1、2对侧枝长度和粗度仅与胸径生长正相关;第3对侧枝倾角与接干处主干直径和接干基径呈负相关.增加成枝数量,减少单枝生长量,而枝长、基径合计不减少,能增大接干高度和接干处主干直径;第4对侧枝长度、粗度与主干、接干粗生长正相关;第5对侧枝长度、粗度与胸径生长正相关,而其以下侧枝对主干和接干的生长影响较小.      

石河子市售桶装纯净水及生活饮用水的细菌学检验

[目的]为评估石河子市饮用水的微生物学指标提供科学依据。[方法]用常规的微生物学检验和计数方法,对石河子市市售的7种品牌桶装纯净水及生活饮用水中的细菌总数和大肠杆菌菌群数进行了计数,检验了石河子市市民饮用水的卫生指标。[结果]检测的纯净水1#、2#、3#、4#(生活饮用水)、5#、6#、7#、8#的细菌平均总数分别为6.84、7.67、5.36、2.34、396.75、357.29、425.67、386.92个/ml。纯净水5#、6#、7#、8#的细菌总数均严重超标;纯净水1#、2#、3#、4(#生活饮用水)的细菌总数检测合格。8份水样中大肠杆菌菌群数报告均为阴性。纯净水1#、2#、3#、4(#生活饮用水)符合国标,纯净水5#、6#、7#、8#不符合国标。[结论]纯净水有4种品牌不符合国家规定的饮用水标准,其余3种品牌及生活饮用水均符合国家规定的饮用水标准。     

根除幽门螺杆菌对胃黏膜肠化生的影响

目的：了解幽门螺杆菌(HP)感染伴胃黏膜肠化生者经根除HP后肠化生的变化情况。方法：HP感染伴肠化生者28例口服抗菌药物三联疗法14d，另2l例不予根除HP，6个月后复查胃镜和病理活检。结果：28例中24例HP获根除，肠化生消失或明显减轻者有11／24例，对照组仅有3／2l例，两组差异具有显著性(P＜0．25)。结论：根除HP后肠化生可有效地消除或明显减轻，认为当HP感染伴肠化生时应积极根除HP。