废气生物处理设施排放的微生物气溶胶逸散特征、影响因素与暴露风险研究进展

生物处理技术因其具有高效、成本低廉、操作简便、清洁、无二次污染等特点,已被广泛应用于废气处理方面,但微生物气溶胶会作为二次污染物从废气处理设施排放到周围空气中。由于携带和传播有害微生物,微生物气溶胶对人体健康造成潜在危害和风险。废气生物处理设施既是微生物气溶胶的“汇”,也是微生物气溶胶的“源”。本文阐述了废气生物处理设施微生物气溶胶的逸散水平、群落结构和粒径分布特征,分析了其形成原因、主要来源、影响因素和暴露风险,为废气生物处理设施产生的微生物气溶胶的识别和控制技术研究提供科学依据和参考。     

微生物气溶胶检测技术的研究进展

生物气溶胶中微生物的种类复杂多样,其采集和鉴定是全面掌握微生物气溶胶生物特性的关键,对防控气溶胶病原体传播十分重要.本文简要综述了微生物气溶胶的生物特性和潜在危害性,介绍了微生物气溶胶的一般采集方法,采集器采集生物气溶胶的基本原理、特点和优缺点.将有助于研究人员根据实验目的在采集低浓度生物气溶胶时选择合适的采样器.本文...     

卫生填埋场微生物气溶胶的逸散及潜在风险

随着对微生物气溶胶认识的提高,其产生、来源、扩散及风险研究获得了越来越多的关注。卫生填埋场是微生物气溶胶的重要产生源之一。本文阐述了卫生填埋场气溶胶颗粒中微生物的浓度水平、粒径分布、种群结构,解析了微生物气溶胶的逸散特征及影响因素,介绍了微生物气溶胶对人体健康的潜在风险及评价方法,并展望了未来卫生填埋场逸散微生物的研究趋势及方向,为卫生填埋场微生物气溶胶的控制与削减提供了科学依据和参考。     

微生物气溶胶采集技术的特点及应用

微生物气溶胶是悬浮于空气中粒径差异显著的生物粒子。污水处理、垃圾填埋等污水和固体废弃物的处理过程会产生大量的微生物气溶胶。近年来,随着对微生物气溶胶的不断认识,对其产生、逸散以及危害环境和人体的研究越来越多。在过去的150年,研究者们研发了多种微生物气溶胶采集技术和仪器设备,每种采集技术各有特点和适用条件。本文阐述沉降法、惯性采样法和过滤法3种典型微生物气溶胶采集技术的特点和原理,分析各种采样设备的适用性,为微生物气溶胶的采集和研究提供参考。     

海绵及其共附生微生物的活性物质与化学防御

海绵及其共附生微生物具有多种化学防御途径,具体表现在能够抵御潜在病原微生物、抗鱼类捕食、阻止污浊生物和降解表面活性剂等方面,这可能与海绵及其共附生微生物产生的活性物质有关。本文对海绵及其共附生微生物的化学防御进行讨论,希望对相关机制的揭示有所帮助。     

胎儿肠道微生物的来源及其对胎儿发育的影响

肠道微生物组在调节人体新陈代谢、免疫功能和行为方面至关重要，并且在胎儿时期就已开始建立。母体各部位的微生物及其代谢物通过血液及阴道上行传播至胎儿组织，并影响胎儿的神经系统发育以及免疫系统的建立和启动。胎儿时期微生物的存在、发展及变化等过程对胎儿发育以及胎儿分娩后的健康状态具有深刻意义。本文着重介绍了胎儿时期肠道微生物的初始定植期、来源途径及其对胎儿发育产生的影响，以此更好地理解胎儿时期微生物与胎儿之间的相互作用及其与长期健康的关联，为改善婴儿短期和长期健康的相关研究提供参考。     

军事医学科学院微生物与流行病学研究60周年回顾与前瞻

60年来,军事医学科学院的微生物与流行病学始终致力于防生物危害医学相关领域研究,为我国的新发和再发传染病防控发挥了重要作用.本文从病原微生物的检验和鉴定、新发传染病的发现与追踪、新发虫媒传染病的确认与流行趋势研究、重要病原微生物致病机理和媒介生物学等方面对军事医学科学院微生物与流行病学研究进行了综述.     

人类环境病原真菌——新生隐球菌的社会行为

人类病原真菌代表了病原微生物一个重要类群,主要感染免疫缺陷、受损和受抑制的患者,导致很高的死亡率。绝大多数的人类病原真菌属于环境病原微生物,它们与人类宿主并无长期共同进化史以及紧密的共生关系,这类真菌被称为环境病原真菌。新生隐球菌作为环境病原真菌的模式种,每年导致约60万人死亡。与其他环境病原真菌相似,该菌的致病能力并不由宿主因素驱动,而是衍生于其对于生境压力出色的适应性策略。近几年来的研究表明,群体或社会行为可能作为一个关键环境适应策略,广泛参与新生隐球菌的感染、耐药以及有性生殖过程。本文以新生隐球菌为例,针对生物被膜以及生物被膜样群落,总结其中的群体或社会调控方式,并对其研究前景和临床应用提出了一些思考。     

人为源微生物气溶胶的分布特征及风险研究进展

近年来,新型冠状病毒肺炎疫情全球肆虐,引起了公众对于微生物气溶胶潜在风险的极大关注,其中人为源微生物气溶胶潜在的健康危害逐步成为越来越多学者关注的热点之一。本文综述了近年来4类主要人为源微生物气溶胶的研究现状,比较了不同人为源微生物气溶胶的分布特征和微生物组成特性,并探究了影响微生物气溶胶特征的主要因素及其存在的潜在风险。结果表明,畜禽养殖场微生物气溶胶平均浓度最高,其次是污水处理厂和垃圾填埋场,医院最低。从微生物组成特性来说,不同人为源微生物气溶胶中微生物组成与其产生源密切相关;同时,其组成也受其所处环境条件影响。基于以上分析,本文进一步展望了未来人为源微生物气溶胶的主要研究方向,以期为微生物气溶胶控制标准的制定及控制技术的研发奠定基础。     

昆虫病原微生物在储藏物害虫防治中的研究与应用

储藏物害虫的病原微生物包括病原细菌、真菌、病毒和病原原生动物等.本文综述了储藏物害虫病原微生物的研究与应用概况,并就病原微生物防治与其它防治方法的兼容作了简要概述,以期为储藏物害虫的生物防治提供参考.     

Microbiological Hazards of Household Toilets: Droplet Production and the Fate of Residual Organisms

Large numbers of bacteria and viruses when seeded into household toilets were shown to remain in the bowl after flushing, and even continual flushing could not remove a persistent fraction. This was found to be due to the adsorption of the organisms to the porcelain surfaces of the bowl, with gradual elution occurring after each flush. Droplets produced by flushing toilets were found to harbor both bacteria and viruses which had been seeded. The detection of bacteria and viruses falling out onto surfaces in bathrooms after flushing indicated that they remain airborne long enough to settle on surface throughout the bathroom. Thus, there is a possibility that a person may acquire an infection from an aerosol produced by a toilet.     

The potential spread of infection caused by aerosol contamination of surfaces after flushing a domestic toilet

AIMS: To determine the level of aerosol formation and fallout within a toilet cubicle after flushing a toilet contaminated with indicator organisms at levels required to mimic pathogen shedding during infectious diarrhoea. METHODS AND RESULTS: A semisolid agar carrier containing either Serratia marcesens or MS2 bacteriophage was used to contaminate the sidewalls and bowl water of a domestic toilet to mimic the effects of soiling after an episode of acute diarrhoea. Viable counts were used to compare the numbers of Serratia adhering to the porcelain surfaces and those present in the bowl water before and after flushing the toilet. Air sampling and settle plates were used to determine the presence of bacteria or virus-laden aerosols within the toilet cubicle. After seeding there was a high level of contamination on the porcelain surfaces both under the rim and on the sides of the bowl. After a single flush there was a reduction of 2.0-3.0 log cycles cm(-2) for surface attached organisms. The number of micro-organisms in the bowl water was reduced by 2.0-3.0 log cycles ml(-1) after the first flush and following a second flush, a further reduction of c. 2.0 log cycles ml(-1) was achieved. Micro-organisms in the air were at the highest level immediately after the first flush (mean values, 1370 CFU m(-3) for Serratia and 2420 PFU m(-3) for MS2 page). Sequential flushing resulted in further distribution of micro-organisms into the air although the numbers declined after each flush. Serratia adhering to the sidewalls, as well as free-floating organisms in the toilet water, were responsible for the formation of bacterial aerosols. CONCLUSIONS: Although a single flush reduced the level of micro-organisms in the toilet bowl water when contaminated at concentrations reflecting pathogen shedding, large numbers of micro-organisms persisted on the toilet bowl surface and in the bowl water which were disseminated into the air by further flushes. SIGNIFICANCE AND IMPACT OF THE STUDY: Many individuals may be unaware of the risk of air-borne dissemination of microbes when flushing the toilet and the consequent surface contamination that may spread infection within the household, via direct surface-to-hand-to mouth contact. Some enteric viruses could persist in the air after toilet flushing and infection may be acquired after inhalation and swallowing.     

气溶胶中抗生素抗性基因研究进展

抗生素的不合理使用导致细菌耐药问题日趋严峻,给人类健康造成巨大威胁。学者们对抗生素抗性菌和抗生素抗性基因(antibiotic resistance genes, ARGs)在多种环境介质中的环境行为开展了大量研究。气溶胶作为ARGs的潜在储存库,是抗生素抗性基因在环境中的重要传播途径之一。目前缺乏对其来源、传播、人类接触和健康风险系统性的梳理。本文针对人类生活功能场所、养殖场、城市污水处理厂和医院等4类气溶胶研究的典型场所,重点综述了上述4类典型场所中气溶胶ARGs的来源、传播途径及对人体的暴露和对健康的危害,为气溶胶中ARGs的预防和控制提供参考。     

The weapon potential of a microbe

The designation of a microbe as a potential biological weapon poses the vexing question of how such a decision is made given the many pathogenic microbes that cause disease. Analysis of the properties of microbes that are currently considered biological weapons against humans revealed no obvious relationship to virulence, except that all are pathogenic for humans. Notably, the weapon potential of a microbe rather than its pathogenic properties or virulence appeared to be the major consideration when categorizing certain agents as biological weapons. In an effort to standardize the assessment of the risk that is posed by microbes as biological warfare agents using the basic principles of microbial communicability (defined here as a parameter of transmission) and virulence, a simple formula is proposed for estimating the weapon potential of a microbe.     

Toilet hygiene—review and research needs

The goal of good toilet hygiene is minimizing the potential for pathogen transmission. Control of odours is also socially important and believed to be a societal measure of cleanliness. Understanding the need for good cleaning and disinfecting is even more important today considering the potential spread of emerging pathogens such as SARS-CoV-2 virus. While the flush toilet was a major advancement in achieving these objectives, exposure to pathogens can occur from failure to clean and disinfect areas within a restroom, as well as poor hand hygiene. The build-up of biofilm within a toilet bowl/urinal including sink can result in the persistence of pathogens and odours. During flushing, pathogens can be ejected from the toilet bowl/urinal/sink and be transmitted by inhalation and contaminated fomites. Use of automatic toilet bowl cleaners can reduce the number of microorganisms ejected during a flush. Salmonella bacteria can colonize the underside of the rim of toilets and persist up to 50 days. Pathogenic enteric bacteria appear in greater numbers in the biofilm found in toilets than in the water. Source tracking of bacteria in homes has demonstrated that during cleaning enteric bacteria are transferred from the toilet to the bathroom sinks and that these same bacteria colonize cleaning tools used in the restroom. Quantitative microbial risk assessment has shown that significant risks exist from both aerosols and fomites in restrooms. Cleaning with soaps and detergents without the use of disinfectants in public restrooms may spread bacteria and viruses throughout the restroom. Odours in restrooms are largely controlled by ventilation and flushing volume in toilet/urinals. However, this results in increased energy and water usage. Contamination of both the air and surfaces in restrooms is well documented. Better quantification of the risks of infection are needed as this will help determine what interventions will minimize these risks.     

Conservation and divergence of signalling pathways between roots and soil microbes – the Rhizobium-legume symbiosis compared to the development of lateral roots, mycorrhizal interactions and nematode-induced galls

This review compares endophytic symbiotic and pathogenic root–microbe interactions and examines how the development of root structures elicited by various micro-organisms could have evolved by recruitment of existing plant developmental pathways. Plants are exposed to a multitude of soil micro-organisms which affect root development and performance. Their interactions can be of symbiotic and pathogenic nature, both of which can result in the formation of new root structures – how does the plant regulate the different outcomes of interactions with microbes? The idea that pathways activated in plant by micro-organisms could have been `hijacked' from plant developmental pathways is not new, it was essentially proposed by P. S. Nutman in 1948, but at that time, the molecular evidence to support that hypothesis was missing. Genetic evidence for overlaps between different plant–microbe interactions have previously been examined. This review compares the physiological and molecular plant responses to symbiotic rhizobia with those to arbuscular mycorrhizal fungi, pathogenic nematodes and the development of lateral roots and summarises evidence from both molecular and cellular studies for substantial overlaps in the signalling pathways underlying root–micro-organism interactions. A more difficult question has been why plant responses to micro-organisms are so similar, even though the outcomes are very different. Possible hypotheses for divergence of signalling pathways and future approaches to test these ideas are presented.     

Axenic and gnotobiotic insect technologies in research on host–microbiota interactions

Insects are one of the most important animal life forms on earth. Symbiotic microbes are closely related to the growth and development of the host insects and can affect pathogen transmission. For decades, various axenic insect-rearing systems have been developed, allowing further manipulation of symbiotic microbiota composition. Here we review the historical development of axenic rearing systems and the latest progress in using axenic and gnotobiotic approaches to study insect–microbe interactions. We also discuss the challenges of these emerging technologies, possible solutions to address these challenges, and future research directions that can contribute to a more comprehensive understanding of insect–microbe interactions.     

Genesis of pandemic influenza

During the last decade the number of reported outbreaks caused by highly pathogenic avian influenza (HPAI) in domestic poultry has drastically increased. At the same time, low pathogenic avian influenza (LPAI) strains, such as H9N2 in many parts of the Middle East and Asia and H6N2 in live bird markets in California, have become endemic. Each AI outbreak brings the concomitant possibility of poultry-to-human transmission. Indeed, human illness and death have resulted from such occasional transmissions with highly pathogenic avian H7N7 and H5N1 viruses while avian H9N2 viruses have been isolated from individuals with mild influenza. The transmission of avian influenza directly from poultry to humans has brought a sense of urgency in terms of understanding the mechanisms that lead to interspecies transmission of influenza. Domestic poultry species have been previously overlooked as potential intermediate hosts in the generation of influenza viruses with the capacity to infect humans. In this review, we will discuss molecular and epidemiological aspects that have led to the recurrent emergence of avian influenza strains with pandemic potential, with a particular emphasis on the current Asian H5N1 viruses.     

二种吸痰方法的对比研究

目前临床上常用的吸痰方式在操作过程中会产生大量的微生物气溶胶,经实验测定,最高可达33970cfu／M^3的含菌微粒喷出,污染各种物品表面,干燥后形成再生气溶胶随气流漂散,造成空气污染和交叉感染。为此,研制了一种密闭式吸痰管,在操作使用中可将产生的痰液气溶胶完全封闭在吸痰管内,经试用,与常规使用的开放式吸痰管相比,可基本消除因吸痰操作所引起的空气微生物污染。     

Evolution of fungal pathogens in domestic environments?

Specific indoor environments select for certain stress-tolerant fungi and can drive their evolution towards acquiring medically important traits. Here we review the current knowledge in this area of research, focussing on the so-called black yeasts. Many of these melanised stress-tolerant organisms originate in unusual ecological niches in nature, and they have a number of preadaptations that make them particularly suited for growth on human-made surfaces and substrates. Several pathogenic species have been isolated recently from various domestic habitats. We argue that in addition to enriching for - potentially - pathogenic species, the selection pressure and stress acting on microorganisms in indoor environments are driving their evolution towards acquiring the missing virulence factors and further enhancing their stress tolerance and pathogenic potential. Some of the polyextremotolerant fungi are particularly problematic: they can grow at elevated temperatures, and so they have a higher potential to colonise warm-blooded organisms. As several species of black fungi are already implicated in health problems of various kinds, their selection and possible evolution in human environments are of concern.