畜禽养殖场排放物病原微生物危险性调查

以粪大肠菌群和沙门菌为指标,采集江苏省内10家不同养殖类型畜禽养殖场的排放物及其周边水、土样共37个进行观察与计数,同时分析排放污水中大肠杆菌的耐药性以及禽畜排泄物对土壤和水体耐药细菌数的影响.结果表明:调查的10家养殖场中有9家粪便未经无害化处理直接排放到水体或施于农田,且排放物的粪大肠菌群数全部严重超标,沙门菌检出率达19%,施新鲜粪肥的土壤中粪大肠菌群数(MPN,最大可能数)在105 g-1以上,水体中分离出的大肠杆菌表现出多重耐药性,抗生素抗性细菌总数也远高于未施新鲜粪肥的土壤及水体.     

广州市区人工湖泊PFU原生动物群落群集过程及其对水质差异的指示作用

应用PFU法(GB／T12990-91)对广州市区主要湖泊——流花湖、荔湾湖和麓湖的原生动物群落与水质进行研究．结果表明：用PFU法所测定和计算的原生动物群集的种类数、植鞭虫指数、群集参数(SeqG、T90%)、群落多样性指数d和群落污染值(CPV)等都能较好地指示3个人工湖泊水质的差异，水质由优到劣的排列顺序为麓湖＞荔湾湖＞流花湖．流花湖、荔湾湖和麓湖目前虽仍处于富营养状态，但清污截流等对城市湖泊污染的综合治理措施可以减少湖泊外部营养物负荷及沉积物内负荷，降低水体的营养盐含量，有助于原生动物群落的恢复．图3表3参16     

环境水体中肠道病原细菌定量PCR检测与膜过滤分析方法的比较

采用通用引物,通过实时荧光定量PCR方法(QPCR),对西安市5个地表水体中肠道病原细菌的细胞密度进行了分析.检测水样体积为100mL,分别于2006年3～6月取自水源水(黑河)、景观娱乐用水(大唐芙蓉园北湖和兴庆湖)、纳污河(浐河)和未消毒的二级出水(北石桥污水处理厂),并将QPCR检测结果与滤膜法(MF)测得的细菌总数、大肠菌群和粪大肠杆菌CFU结果进行了比较分析.5个水体(n=60)检测结果显示,QPCR检测结果是大肠菌群CFU的2.2～5倍,是粪大肠杆菌CFU的7～14倍.病原细菌检测的几何平均值范围,QPCR法在25～67000 CCE·100mL-1之间,MF法大肠菌群在3～45000 CFU·100mL-1之间,粪大肠菌群在0～3000 CFU·100mL-1之间(n=60).两种方法的检测结果使用Spearman秩相关法来计算,结果显示,QPCR检测结果与大肠菌群、细菌总数以及粪大肠杆菌CFU均呈现显著正相关,秩相关系数分别为r=0.983、r=0.908和r=0.948.     

生态环境监测全过程病原微生物安全风险识别评估及个体防护

生态环境监测人员在工作中面临病原微生物安全风险。调研发现,已颁布的相关法律法规、标准和规定,多侧重于实验室及医务人员的病原微生物安全防护,缺少生态环境监测人员在采样、样品运输和交接、废弃物处置等过程中的病原微生物安全规范,新冠肺炎疫情期间的防护指导文件比较笼统。笔者在已颁布的法律法规和各项标准基础上,识别和评估生态环境监测全过程病原微生物安全风险,提出相应的监测要求和人员防护建议,针对采样、样品运输和交接、实验室分析和废弃物处置过程提出个人防护措施及突发情况下的应急防护措施。     

农村污水膜生物反应器系统中微生物群落解析

农村污水的随意排放和未加限制的灌溉回用可能会导致水源地环境污染加剧,并且其中潜在的病原微生物对周边淡水资源安全和农村居民的身心健康造成潜在的威胁.为了解农村污水的微生物群落组成,为后续污水灌溉的病原微生物风险评价提供理论依据,采用末端限制性片段长度多态性(T-RFLP)和16S r DNA基因克隆文库技术研究农村污水膜生物反应器(MBR)系统中的微生物群落多样性,并结合实时荧光定量PCR方法监测处理前后典型病原菌——弓形菌(Arcobacter spp.)以及总细菌数量的变化.从未处理的农村污水中获取的73个阳性克隆测序结果表明,其主要细菌类群为变形菌门(91.8%)、厚壁菌门(2.70%)、拟杆菌门(1.40%),以及部分不可培养细菌(4.10%).其中弓形菌属是ε-变形菌门的优势菌,也是农村污水中的优势菌株,占克隆总数的68.5%.TRFLP的结果表明,不同处理工艺阶段的主要细菌类群及丰度明显不同,调节池的物种丰度(S)、Shannon-Wiener(H)和物种均匀度(E)最高,分别为43.0、3.56和0.95.定量PCR结果显示未处理的农村污水中弓形菌数量高达(1.09±0.064 0)×1011copies·L-1,该结果与克隆文库结果均表明弓形菌在污水中确实占较高比例.与未处理的农村污水相比,处理后的出水中所监测的弓形菌及细菌总拷贝数分别减少了2~3个数量级,说明MBR处理系统在一定程度上能够去除微生物.处理后的再生水理化指标及指示菌卫生指标均符合农田灌溉用水标准,但其中残留病原微生物引发的健康风险仍需进一步评价.     

九龙江流域潜在病原菌污染分析

近年来,由于流域经济快速发展和城镇化进程加快等原因,九龙江水污染问题日趋严重.为全面认识九龙江流域病原菌的分布状况,应用16S rRNA基因-454焦磷酸测序技术测定九龙江支流西溪、北溪水体和沉积物中细菌16S rRNA基因V1~V3高变区,共获得204 216条高质量序列.通过与病原菌参考数据库对比分析发现,九龙江分布有68个潜在病原菌属,占序列总量的6.1%.其中梭菌属(Clostridium)、分支杆菌属(Mycobacterium)和鞘氨醇单胞菌属(Sphingomonas)在所有样品中都有检出,且丰度最高,分别占病原菌属序列总量的54.5%、5.9%和5.6%.在种水平上,九龙江分布有48种病原菌,占序列总量的0.76%.其中Afipia felis、Mycobacterium asiaticum、Clostridium baratii、Brucella melitensis和Delftia tsuruhatensis是丰度最高的5种病原菌,分别占病原菌种序列总量的48.9%、20.3%、8%、2.7%和1.7%.统计分析表明,九龙江水体中分布的病原菌种类数(属或种)显著高于沉积物中,且西溪水体检出的病原菌种类(属或种)和丰度最高,说明九龙江水体,尤其是西溪水体受病原菌污染的风险较高.此外,相关分析表明,九龙江水体中病原菌的种类数(属或种)和丰度与营养盐(氮、磷)有着显著的正相关关系,说明九龙江水体中分布的病原菌与沿岸的人类活动,如养殖业、污水排放等密切相关.因此,为保证流域的公共卫生安全,需进一步加强污染源清理整顿工作,开展水环境病原菌的实时监测.     

Antibacterial activity of different natural honeys from Transylvania,Romania

Honey is used in food industry and medicine due to its nutritive, therapeutic and dietetic qualities. The microbiological characteristics of 10 unpasteurized honey samples of known origin, collected from Transylvania beekeepers (Romania) were determined. The antibacterial activity of these types of honey against Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Salmonella enteritidis, Salmonella anatum, Salmonella choleraesuis, Bacillus cereus, Bacillus subtilis subsp. spizizenii and Listeria monocytogenes strains was studied. The most sensitive to the antibacterial activity were the two staphylococus strains (the largest diameter of inhibition zone was 18 mm) and B. subtilis strains (13.5 mm). The strains of B. cereus, E. coli, L. monocytogenes and Salmonella spp. were found to present resistance to some of the honey samples. Manna, sunflower and polyfloral honeys presented high antibacterial activity while acacia and linden honeys had a lower activity in terms of the number of sensible strains. Statistical analysis shows that the type of strains and the type of honey have influence on the diameter of inhibition.     

浅论微生物技术控藻

富营养化水体会引起藻类增殖，影响人类的生存环境。阐述了利用病毒、原生动物、细菌等微生物技术控制富营养化藻类的研究进展，并对病毒控藻技术应用时的两个问题进行了讨论，认为利用微生物技术控藻需要对生态系统进行更加深入的认识和掌握。     

Quantification of multi-antibiotic resistant opportunistic pathogenic bacteria in bioaerosols in and around a pharmaceutical wastewater treatment plant

Pharmaceutical wastewater treatment plants(WWTPs) are thought to be a "seedbed" and reservoirs for multi-antibiotic resistant pathogenic bacteria which can be transmitted to the air environment through aeration. We quantified airborne multi-antibiotic resistance in a full-scale plant to treat antibiotics-producing wastewater by collecting bioaerosol samples from December2014 to July 2015. Gram-negative opportunistic pathogenic bacteria(GNOPB) were isolated, and antibiotic susceptibility tests against 18 commonly used antibiotics, including 11 β-lactam antibiotics, 3 aminoglycosides, 2 fluoroquinolones, 1 furan and 1 sulfonamide, were conducted.More than 45% of airborne bacteria isolated from the pharmaceutical WWTP were resistant to three or more antibiotics, and some opportunistic pathogenic strains were resistant to 16 antibiotics, whereas 45.3% and 50.3% of the strains isolated from residential community and municipal WWTP showed resistance to three or more antibiotics. The calculation of the multiple antibiotic resistance(MAR) index demonstrated that the air environment in the pharmaceutical WWTP was highly impacted by antibiotic resistance, while the residential community and municipal WWTP was less impacted by antibiotic resistance. In addition, we determined that the dominant genera of opportunistic pathogenic bacteria isolated from all bioaerosol samples were Acinetobacter, Alcaligenes, Citrobacter, Enterobacter, Escherichia, Klebsiella, Pantoea, Pseudomonas and Sphingomonas. Collectively, these results indicate the proliferations and spread of antibiotic resistance through bioaerosols in WWTP treating cephalosporin-producing wastewater, which imposed a potential health risk for the staff and residents in the neighborhood, calling for administrative measures to minimize the air-transmission hazard.     

免疫磁珠分离技术在环境病原微生物检测中的应用

介绍免疫磁珠分离技术的原理和操作步骤,分析其主要影响因素.介绍该技术在环境样品病原菌、原虫及病毒检测中的应用及研究进展.环境样品成分复杂,需经适当分离纯化处理再进行病原微生物检测,从而保证检测结果的可信性.免疫磁珠分离技术兼具免疫反应的特异性及磁性分离的快速性,能够有效分离纯化环境水样中的病原微生物,广泛应用于病原微生物的检测.