我国食源性蜡样芽孢杆菌毒力基因和药物敏感性研究

目的 了解我国不同地区食源性蜡样芽孢杆菌的毒力基因携带特点及其对抗生素的敏感性,为食源性食物中毒的防治提供参考依据.方法 采用PCR方法对2011年我国不同地区收集的238株食源性蜡样芽孢杆菌10种毒力基因进行检测;采用微量肉汤稀释法测定其抗生素敏感性.结果 溶血素BL基因、肠毒素T基因和细孢毒素K基因是我国食源性蜡样芽孢杆菌的主要毒力基因,至少携带一个毒力基因的菌株达到检出菌总数的87.4％;蜡样芽孢杆菌对庆大霉素、万古霉素、环丙沙星、复方新诺明的敏感率为100％,对红霉素、四环素、氯霉素、克林霉素的敏感率分别为88.8％、90.2％、99.6％、87.1％,对氨苄西林和头孢噻肟的敏感率仅为0.4％和5.4％.结论 我国食源性蜡样芽孢杆菌毒力基因携带率较高,对食品安全和公共健康构成潜在的威胁;蜡样芽孢杆菌对氨苄西林、头孢噻肟的敏感性差,不应作为经验用药和预防用药.     

红霉素类抗生素电喷雾/飞行时间质谱源内CID研究

本文采用电喷雾 /飞行时间质谱法 ,对 5个红霉素类抗生素进行了源内CID研究 ,并以PEG40 0及各样品质子化分子离子 (MH+ )做为内标物 ,对碎片离子进行了准确质量测定 ,确认了这些碎片离子 ,并总结了此类化合物的裂解规律。样品分子含有去氧氨基糖 (desosamine)或红霉糖 (cladinose)两个糖基片段 ,其中去氧氨基糖易于形成带电离子。另外考察了喷管电压 (NozzlePotential)、溶剂条件等对红霉素类抗生素电喷雾源内CID质谱的影响。     

膜分离技术在抗生素提炼过程中的应用

膜分离过程是一种选择性高,操作简单,能耗低的纯物理分离技术,已在各工业领域和科学研究中得到广泛的应用,文章对膜分离技术在抗生素提炼领域的技术进展进行了较全面的综述。     

Prevalence of Salmonellae on Beef Products at Butcheries and their Antibiotic Resistance Profiles

We determined the aerobic plate count at 5 and 25 °C, presence of total coliforms, fecal coliforms, and Escherichia coli, and prevalence of Salmonella species in 354 meat products collected from butcheries. The aerobic counts varied from 3.5 to 10.7 log₁₀ CFU/g. Most of the microorganisms were psychrotrophic. Coliforms were present in all samples except kidneys. Escherichia coli was present at ≥2 log₁₀ CFU/g in ≥50% of the minced meat, liver, and stew. Salmonella species were present in 9.9% of the samples. Minced meat and tripe contained more salmonellae than the other beef. Serogroup E or G (57.1%) was the most predominant serotype. Tetracycline resistance (33.3%) was higher than that of other antibiotics.     

食源性乳酸菌外获抗药性的研究进展

乳酸菌外获抗药性是指乳酸菌主动或被动地从抗药性菌株上外获抗药性因子。本文对食源性乳酸菌抗药性产生的原因,传递外获抗药性因子的载体及传递方式进行了综述,以期加强人们对抗药性菌株扩增的防范意识。     

解脲支原体对7种抗生素的体外敏感性测定

目的: 了解非淋菌性尿道炎(NGU) 患者解脲支原体(UU) 对7 种抗生素的敏感性。方法: 采用微量肉汤稀释法测定体外药物敏感性, 对培养阳性的150 例患者进行了分析。结果: UU 对 7 种抗生素的敏感性的顺序由高到低依次为:交沙霉素(96 6.7 %) 、强力霉素(90.67 %) 、美满霉素(88.67 %) 、司巴沙星(58.67 %) 、 罗 红 霉 素 (39.33 %) 、 氧 氟 沙 星(18.00 %) 和阿奇霉素(8.00 %) 。UU 耐药率最高的为氧氟沙星(31.33 %), 其次为司巴沙星(18.67 %)和罗红霉素(18.00 %) 。结论: UU 存在多重耐药, 对UU 进行药敏监测对指导临床合理用药及防止耐药株的发生有重要意义。     

食用香料植物的开发利用研究

本文在论述食用香料植物赋香调味作用的基础上,阐述了食用香料植物的防腐抑菌作用、抗氧化作用、健胃驱风等药疗作用。并在广泛调查研究的基础上介绍了100余种已开发利用或未被利用的天然食用香料植物。     

Remote‐Loaded Platelet Vesicles for Disease‐Targeted Delivery of Therapeutics

The recent emergence of biomimetic nanotechnology has facilitated the development of next‐generation nanodelivery systems capable of enhanced biointerfacing. In particular, the direct use of natural cell membranes can enable multivalent targeting functionalities. Herein, this study reports on the remote loading of small molecule therapeutics into cholesterol‐enriched platelet membrane‐derived vesicles for disease‐targeted delivery. Using this approach, high loading yields for two model drugs, doxorubicin and vancomycin, are achieved. Leveraging the surface markers found on platelet membranes, the resultant nanoformulations demonstrate natural affinity toward both breast cancer cells and methicillin‐resistant Staphylococcus aureus. In vivo, this translates to improved disease targeting, increasing the potency of the encapsulated drug payloads compared with free drugs and the corresponding nontargeted nanoformulations. Overall, this work demonstrates that the remote loading of drugs into functional platelet membrane‐derived vesicles is a facile means of fabricating targeted nanoformulations, an approach that can be easily generalized to other cell types in the future.     

分离膜中的新成员——纳滤膜及其在制药工业中的应用

介绍了“纳滤膜”名称的由来，该膜的分离机理和性能，简述了纳滤技术在发酵医药产品生产中液体分离方面的几例应用     

New Beta-lactamases in Candidate Phyla Radiation: Owning Pleiotropic Enzymes Is a Smart Paradigm for Microorganisms with a Reduced Genome

The increased exploitation of microbial sequencing methods has shed light on the high diversity of new microorganisms named Candidate Phyla Radiation (CPR). CPR are mainly detected via 16S rRNA/metabarcoding analyses or metagenomics and are found to be abundant in all environments and present in different human microbiomes. These microbes, characterized by their symbiotic/epiparasitic lifestyle with bacteria, are directly exposed to competition with other microorganisms sharing the same ecological niche. Recently, a rich repertoire of enzymes with antibiotic resistance activity has been found in CPR genomes by using an in silico adapted screening strategy. This reservoir has shown a high prevalence of putative beta-lactamase-encoding genes. We expressed and purified five putative beta-lactamase sequences having the essential domains and functional motifs from class A and class B beta-lactamase. Their enzymatic activities were tested against various beta-lactam substrates using liquid chromatography-mass spectrometry (LC-MS) and showed some beta-lactamase activity even in the presence of a beta-lactamase inhibitor. In addition, ribonuclease activity was demonstrated against RNA that was not inhibited by sulbactam and EDTA. None of these proteins could degrade single- and double-stranded-DNA. This study is the first to express and test putative CPR beta-lactamase protein sequences in vitro. Our findings highlight that the reduced genomes of CPR members harbor sequences encoding for beta-lactamases known to be multifunction hydrolase enzymes.