人粪便中分离的噬菌蛭弧菌生物学特性的研究

本文研究了人粪便中分离的噬菌蛭弧菌的生物学特性,测定了它们的生长曲线,并利用微孔滤膜过滤和机械振荡的方法,研究了它们的吸附和穿入动力学,发现链霉素、庆大霉素和卡那霉素能抑制蛭弧菌的吸附;青霉素不影响蛭弧菌的吸附和穿入,但抑制蛭弧菌在宿主内的生长过程。从人粪中分出的噬菌蛭弧菌不仅能裂解大部分需氧的革兰氏阴性菌,而且在微氧条件下也能裂解厌氧菌中的二株脆弱拟杆菌。我们发现一株人粪便中分出的噬菌蛭弧菌能形成蛭弧菌囊体——它的休眠态,它对高热、紫外线照射和真空干燥的耐受力较相应的繁殖体强,看来它是蛭弧菌保持生命期限的一种方式。     

噬菌蛭弧菌简易保存方法的研究

本文报道了噬菌蛭弧菌在自来水宿主软琼脂中,于4℃环境(冰箱)存活的时间.发现噬菌蛭弧菌在自来水宿主软琼脂中,于4℃冰箱中保存,至少可以存活3个月以上,一般为5～8个月左右,最长时间可达18个月。但在自来水宿主双层琼脂平板上形成的噬斑数目,随着保存时间的延长,则有不同程度的减少。     

噬菌蛭弧菌噬菌斑的鉴别与纯化的研究

本文报告了使用１／５００营养肉汤双层琼脂培养基,在含有宿主菌及寄生菌混合物的软琼脂层中,蛭弧菌、变形虫及鞭毛虫等均可形成噬菌斑,但其大小、形态、扩展速度不同。鉴别方法除依据噬菌斑形态特征外,主要靠相差显微镜下的形态学观察。蛭弧菌的纯化用单斑传代,一个直径为１ｍｍ的噬菌斑含有约１０^５－６ｐｆｕ／ｍｌ（每毫升噬菌斑形成单位）。     

蛭弧菌及生态防治概述

对噬菌蛭弧菌和蛭弧菌的主要生物学特性—寄生性,进行了一些探讨,并对其生态特性和在水产养殖等生态防治中的应用,以及对生态防治的认识进行了阐释和探讨。     

鱼病蛭弧菌的微生态学初步研究

本次以鲫鱼出血性腹水病病原菌点状产气单胞菌（Ａｅｒｏｍｏｎａｓ Ｐｕｎｃｔａｔａ）为宿主菌。从自然界分离获得６株噬菌蛭弧菌菌株,它们具有噬菌蛭弧菌的生物学特性。研究表明,这６株蛭弧菌的最适培养条件为温度２５￣２８℃,ｐＨ７．２,有溶菌性,能裂解多种鱼类病原菌。其中对蛭弧菌Ｂｄｓ－４菌株在实验条件下对病原菌的自然净化作用等方面进行了研究。说明蛭弧菌是精养鱼糖水体中某些致病菌的自然净化的重要生物因素之     

噬菌蛭弧菌对嗜水气单胞菌裂解作用的研究

本文报道了8株噬菌蛭弧菌对河水中分离的9株嗜水气单胞菌的裂解作用。结果发现,噬菌蛭弧菌Bd32的裂解率为77.78％;Bd83、Bd98的裂解率为88.89％,其余5株噬菌蛭弧菌对9株嗜水气单胞菌全部裂解。     

ECOLOGICAL CONDITIONS AFFECT EVOLUTIONARY TRAJECTORY IN A PREDATOR–PREY SYSTEM

The arms race of adaptation and counter adaptation in predator–prey interactions is a fascinating evolutionary dynamic with many consequences, including local adaptation and the promotion or maintenance of diversity. Although such antagonistic coevolution is suspected to be widespread in nature, experimental documentation of the process remains scant, and we have little understanding of the impact of ecological conditions. Here, we present evidence of predator–prey coevolution in a long-term experiment involving the predatory bacterium Bdellovibrio bacteriovorus and the prey Pseudomonas fluorescens , which has three morphs (SM, FS, and WS). Depending on experimentally applied disturbance regimes, the predator–prey system followed two distinct evolutionary trajectories, where the prey evolved to be either super-resistant to predation (SM morph) without counter-adaptation by the predator, or moderately resistant (FS morph), specialized to and coevolving with the predator. Although predation-resistant FS morphs suffer a cost of resistance, the evolution of extreme resistance to predation by the SM morph was apparently unconstrained by other traits (carrying capacity, growth rate). Thus we demonstrate empirically that ecological conditions can shape the evolutionary trajectory of a predator–prey system.     

Predation of human pathogens by the predatory bacteria Micavibrio aeruginosavorus and Bdellovibrio bacteriovorus

Aims: The focus of this study was to evaluate the potential use of the predatory bacteria Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus to control the pathogens associated with human infection. Methods and Results: By coculturing B. bacteriovorus 109J and M. aeruginosavorus ARL‐13 with selected pathogens, we have demonstrated that predatory bacteria are able to attack bacteria from the genus Acinetobacter, Aeromonas, Bordetella, Burkholderia, Citrobacter, Enterobacter, Escherichia, Klebsiella, Listonella, Morganella, Proteus, Pseudomonas, Salmonella, Serratia, Shigella, Vibrio and Yersinia. Predation was measured in single and multispecies microbial cultures as well as on monolayer and multilayer preformed biofilms. Additional experiments aimed at assessing the optimal predation characteristics of M. aeruginosavorus demonstrated that the predator is able to prey at temperatures of 25–37°C but is unable to prey under oxygen‐limiting conditions. In addition, an increase in M. aeruginosavorus ARL‐13 prey range was also observed. Conclusions: Bdellovibrio bacteriovorus and M. aeruginosavorus have an ability to prey and reduce many of the multidrug‐resistant pathogens associated with human infection. Significance and Impact of the Study: Infectious complications caused by micro‐organisms that have become resistant to drug therapy are an increasing problem in medicine, with more infections becoming difficult to treat using traditional antimicrobial agents. The work presented here highlights the potential use of predatory bacteria as a biological‐based agent for eradicating multidrug‐resistant bacteria, with the hope of paving the way for future studies in animal models.