605例临床感染标本的细菌学研究

为了解感染性疾病的细菌分布及混合感染,给临床细菌感染性疾病的正确诊断和有效治疗提供依据,对６０５份临床感染标本进行了细菌学研究。结果表明,混合感染已成为临床细菌感染的重要类型（６９５％）,正常菌群和条件致病菌已成为当前细菌感染性疾病的重要病原菌。     

正常菌群对常见致病菌拮抗作用的研究

生物拮抗作用是微生物种群关系研究的一个侧面,实验中我们使用从皮肤上分离的常住菌——痤疮丙酸杆菌(A14-1)和表皮葡萄球菌(F65)对常见致病菌如金黄色葡萄球菌(C189)、绿脓杆菌(C8514)和埃希氏大肠杆菌(C1356)的体外拮抗试验表明,它们具有明显的拮抗作用,拮抗作用一般从48小时开始,72小时明显。而皮肤常住菌间无拮抗作用,相反它们还有协同作用,这对于皮肤的自净以及维持皮肤的微生态平衡具有重要的作用。此外,实验中还进行了乳杆菌和双歧杆菌等正常菌群分离株与上述常见致病菌的体外拮抗试验,结果表明也     

引起机会性感染的常见病原体分析

机会性致病微生物在机体免疫功能正常时不能导致具有明显临床症状的感染性疾病, 但当机体微生态失调或免疫功能受损时, 可导致明显的临床感染性疾病, 甚至危及患者的生命。现代医疗技术的进步使先天性免疫功能缺陷者、肿瘤患者等免疫功能降低者生存期延长, 滥用抗生素致使正常微生态失调, 以及大量耐药变异菌株出现等诸多因素使得临床机会性感染逐渐增多。机会性感染多发生于免疫功能降低者, 可为耐药菌或多重耐药菌感染, 或为正常菌群致病; 临床表现复杂且不典型, 给治疗带来极大困难。了解常见机会性感染病原体及其特点对及时诊断和治疗机会性感染具有重要的临床意义。     

我国临床新现的条件致病真菌感染

机会性真菌的感染近年不断增多,出现的新菌种也随之增多。尤其是近年不断出现少见的机会性真菌感染,包括酵母和酵母样真菌、暗色孢科的腐生菌、地域性流行的少见双相真菌感染及一些罕见真菌感染等。由于此类真菌引起的感染难于诊断并且难鉴定到属,流行病学较难解释,且一些菌对抗真菌药物治疗抵抗,故所引起的感染危害更大。应引起真菌工作者的高度重视。     

关于“试管婴儿”的几个重要概念的辨析

通过对“试管婴儿”技术的背景做了简略介绍,针对“试管婴儿”与试管、体内受精与体外受精、人工授精与人工受精、“试管婴儿”与“克隆人”、“试管婴儿与“设计试管婴儿”几个关于“试管婴儿”的重要概念做了详细的辨析,以供中学生物学教学参考.     

“条件必需氨基酸——Gln”生理功能的研究进展及应用现状

Gln是一种“条件必需氨基酸” ,本文详细论述了Gln的研究背景 ,Gln的生理功能包括在免疫活性细胞、骨骼肌、胃肠道、肾脏、肝脏和大脑中的作用 ,并且讨论了Gln的输送机制和Gln在营养液中的应用现状     

神经冲动相“遇”会返回吗？——谈动作电位形成的条件

在动物离体神经纤维的2端同时给予刺激,产生2个同等强度的神经冲动,2冲动传导至中点并相遇后,是相遇“停止”还是相遇“返回”？分析了动作电位形成的条件、神经细胞兴奋性周期性变化的原因,以及中学教学中大学教材初等化而不失科学性的处理策略。     

“探究种子萌发的环境条件”实验的改进

对课本中“探究种子萌发的环境因素”实验的方法和材料进行了改进,采用“除氧法”避免了新变量的引入,同时选用绿豆作为实验材料使萌发效果更加明显。通过分析实验结果,对教材的实验结论进行了修正。     

基于三重表征理论的生物学概念教学设计——以“性染色体上的基因传递”为例

基于三重表征理论,以“性染色体上的基因传递”概念教学为例,创设贯穿始终的问题情境与外显三重表征的课前、课中、课后一体化学习活动序列,带领学生像科学家一样发现问题、分析问题、构建概念,在真实情境中解决问题,发展生物学学科核心素养。     

肠道菌群与糖尿病的研究进展

近年来的研究表明,糖尿病的病因除了肥胖、遗传、胰岛素自身功能不全外,还可能与肠道菌群密切相关。目前认为,肠道菌群的结构性失衡是糖尿病发生的一种可能的重要机制。具体表现为菌群多样性和稳定性遭到破坏,如有益菌菌群的减少亦或条件致病菌菌群的增强,可以诱发肠道产生低度慢性炎症,促使细菌内毒素释放,从而导致胰岛素抵抗。籍此进一步影响机体对糖和能量的吸收,同时促进脂肪的合成与存储,即糖尿病病变发生。与此,饮食干预疗法和益生菌的摄入治疗,尤其是后者,可明显改善病情。其可能的机制在于调节肠道屏障功能、通透性以及肠黏膜免疫功能。     

某高校学生肠道菌群初步调查

目的 探讨在校大学生肠道菌群的分布,为预防肠道致病菌导致的感染提供科学依据。方法 取新鲜粪便标本,接种于肠道选择平板,筛选正常菌群、肠道致病菌和机会致病菌,以K-B法确定其药物敏感性。结果 大学生肠道菌群以克雷伯杆菌、费劳地枸椽酸杆菌、阴沟肠杆菌及白色念珠菌较多见,男性多见于女性,差异有显著性（P＜0.05）。经常校外就餐者肠道致病菌和条件致病菌检出率较高,与偶有校外就餐者相比,差异有显著性（P＜0.01）。结论 安徽理工大学医学院大学生肠道菌群以费劳地枸椽酸杆菌、阴沟肠杆菌、克雷伯杆菌及白色念珠菌较多见,并就餐方式密切相关。克雷伯杆菌耐药谱较广,应引起足够重视。     

病原生物学实验教学中应用多学科整合及虚拟实验的探索

病原生物学作为一门实践性很强的学科,其实验教学在其中发挥重要的作用。为了提高病原生物学实验的系统性和可操作性,结合微生态学、医学微生物学及免疫学各自学科特点,进行以"抗生素诱导的肠道菌群失调"为例探讨病原生物学整合实验。由于临床标本及实验条件的限制,采用可视化虚拟实验进行消化性溃疡中病原菌分离与鉴定及微生态菌群分析实验。这将为病原生物学实验教学的改革提供相应参考。     

Synthesis and antibiofilm evaluation of 3-hydroxy-2,3-dihydroquinazolin-4(1H)-one derivatives against opportunistic pathogen Acinetobacter baumannii

The emergence of multidrug resistant microorganisms has triggered the impending need for new aitimicrobial strategies. The antivirulence strategy with the benefite of alleviating the drug resistance becomes the focus of research. In this study, 22 quorum sensing inhibitors were synthesized by mimicking the structure of autoinducer and acinetobactin and up to 34% biofilm inhibition was observed with 5u. The biofilm inhibition effect was further demonstrated with extracellular polysaccharides inhibition and synergism with Gentamycin sulphate.     

Comparison of fecal biota from specific pathogen free and feral mice

Specific pathogen free (SPF) rodents are derived from germfree animals that are colonized with Schaedler's flora, a cocktail of eight bacterial strains isolated from the natural biota of mice. During successive generations SPF animals acquire a complex biota, but it is not known how similar it is to natural mouse biota. Therefore, fecal pellets of two feral mice and three SPF mice were studied by small subunit ribosomal DNA sequence analysis. After amplification of 16S rDNA by Bacterial Kingdom-specific primers, 132 rDNA clones from feral mice and 219 clones from SPF mice were placed phylogenetically. Forty-four percent of recovered rDNAs from feral mice were from organisms belonging to the Ribosomal Database Project's Bacteroides Group with significant proportions also coming from lactobacilli, the Clostridium coccoides Group and the Clostridium leptum Group. Although the SPF biota appeared equally complex at lower phylogenetic levels, the major phylogenetic groups represented were less diverse in that 92% of rDNA's from SPF mice mapped to groups of clostridia with 79% to the C. coccoides Group alone. Given the number of physiological parameters influenced by the gut biota and the importance of mice in biomedical research, further investigations are warranted.     

An overview of foodborne pathogen detection: In the perspective of biosensors

Food safety is a global health goal and the foodborne diseases take a major crisis on health. Therefore, detection of microbial pathogens in food is the solution to the prevention and recognition of problems related to health and safety. For this reason, a comprehensive literature survey has been carried out aiming to give an overview in the field of foodborne pathogen detection. Conventional and standard bacterial detection methods such as culture and colony counting methods, immunology-based methods and polymerase chain reaction based methods, may take up to several hours or even a few days to yield an answer. Obviously this is inadequate, and recently many researchers are focusing towards the progress of rapid methods. Although new technologies like biosensors show potential approaches, further research and development is essential before biosensors become a real and reliable choice. New bio-molecular techniques for food pathogen detection are being developed to improve the biosensor characteristics such as sensitivity and selectivity, also which is rapid, reliable, effective and suitable for in situ analysis. This paper not only offers an overview in the area of microbial pathogen detection but it also describes the conventional methods, analytical techniques and recent developments in food pathogen detection, identification and quantification, with an emphasis on biosensors.     

The temporal pattern of responding in conditioned bar-press suppression: the role of the context switch and training mode

The present study examined the temporal pattern of responding in a conditioned bar-press suppression task in rats. Rats were exposed to either a 30-s or a 120-s conditioned stimulus (CS) followed by a footshock. Training took place either while the rats were lever-pressing for water (online), or with the lever removed from the box (offline). They were then exposed to the CS while they were lever-pressing for water, either in the training context or in a different context. Bar-press suppression during the CS was constant across the duration of the CS during training, but was restricted to the initial portion of the CS at the time of testing, especially when subjects were tested in a different context. Those results replicate the reactive (as opposed to anticipatory) pattern observed in a lick suppression procedure by Jozefowiez et al. (2011) and indicate that a change in context at the time of testing might be critical for its expression.