Bacillus anthracis: Molecular taxonomy, population genetics, phylogeny and patho-evolution

Bacillus anthracis, the etiological agent of anthrax, manifests a particular bimodal lifestyle. This bacterial species alternates between short replication phases of 20–40 generations that strictly require infection of the host, normally causing death, interrupted by relatively long, mostly dormant phases as spores in the environment. Hence, the B. anthracis genome is highly homogeneous. This feature and the fact that strains from nearly all parts of the world have been analysed for canonical single nucleotide polymorphisms (canSNPs) and variable number tandem repeats (VNTRs) has allowed the development of molecular epidemiological and molecular clock models to estimate the age of major diversifications in the evolution of B. anthracis and to trace the global spread of this pathogen, which was mostly promoted by movement of domestic cattle with settlers and by international trade of contaminated animal products. From a taxonomic and phylogenetic point of view, B. anthracis is a member of the Bacillus cereus group. The differentiation of B. anthracis from B. cereus sensu stricto, solely based on chromosomal markers, is difficult. However, differences in pathogenicity clearly differentiate B. anthracis from B. cereus and are marked by the strict presence of virulence genes located on the two virulence plasmids pXO1 and pXO2, which both are required by the bacterium to cause anthrax. Conversely, anthrax-like symptoms can also be caused by organisms with chromosomal features that are more closely related to B. cereus, but which carry these virulence genes on two plasmids that largely resemble the B. anthracis virulence plasmids.     

Lipopeptides Extract from Bacillus Amyloliquefaciens Induce Human Oral Squamous Cancer Cell Death

A lipopeptide extract of Bacillus amyloliquefaciens BACY1 (BLE) was found to induce cell death in human oralsquamous cell carcinoma (OSCC) cell lines, SCC4 and SCC25, in this study. The results of MTT assay showedthat BLE inhibited OSCC cell proliferation in a dose-dependent manner. BLE was also effective in increasingthe sub-G1 phases. Furthermore, when membrane damage in SCC4 cells treated with BLE was monitored byLDH assay, release of LDH was significantly increased. The protein and mRNA levels of pro-apoptotic Bax, andcaspase-3 were up-regulated by BLE. Taken together, these results suggest that BLE induces apoptosis and theninhibits the cell proliferation of human OSCC cells.     

枯草杆菌、肠球菌二联活菌多维颗粒联合蒙脱石散治疗新生儿黄疸疗效观察

目的探讨枯草杆菌、肠球菌二联活菌多维颗粒（妈咪爱）联合蒙脱石散治疗新生儿黄疸的疗效。方法选取2009年1月。2010年6月本院儿科收治的152例新生儿黄疸患儿,随机等分成两组,对照组给予蓝光照射、酶诱导剂等常规综合治疗,观察组在此基础上加用枯草杆菌、肠球菌二联活菌多维颗粒联合蒙脱石散,观察两组患儿治疗后的疗效。结果与对照组相比,观察组胆红素的日均下降值升高,黄疸消退时间缩短,差异均有统计学意义（P〈0．05）。结论枯草杆菌、肠球菌二联活菌多维颗粒联合蒙脱石散治疗新生儿黄疸疗效确切,可加速胆红素分解排出和减少重吸收。     

一种无磷洗衣粉的消毒效果研究

[目的]研究一种新型环保无磷洗衣粉对不同种类细菌的杀灭效果以及对乙型肝炎表面抗原（HBsAg）的破坏作用。[方法]采用载体定量杀灭实验的方法评价浓度为1.0%（w/v）、5.5%（w/v）和10.0%（w/v）的某品牌无磷洗衣粉溶液对大肠埃希氏菌（Escherichia coli）、金黄色葡萄球菌（Staphylococcus aureus）、枯草杆菌黑色变种（Bacillus subtilis var.neger）芽胞的杀灭效果及其对乙型肝炎表面抗原（HBsAg）的破坏效果。[结果]1.0%的无磷洗衣粉溶液作用10min,对大肠埃希氏菌的杀灭率为（99.90±0.01）%,达到消毒效果要求。10.0%的无磷洗衣粉溶液作用20min,对金黄色葡萄球菌的杀灭率为（99.92±0.01）%,达到消毒效果;作用40min,对枯草杆菌黑色变种芽胞的杀灭率仅为（8.06±0.05）%;作用60min,不能破坏乙型肝炎表面抗原（HBsAg）。[结论]所检测环保无磷洗衣粉的杀菌效果随溶液中洗衣粉浓度的增高以及与微生物作用时间的延长而增强;对大肠杆菌的的杀灭作用明显强于对金黄色葡萄球菌的杀灭作用,而对枯草杆菌黑色变种芽胞的杀灭效果及对乙型肝炎表面抗原（HBsAg）的破坏作用较差。     

蜡样芽孢杆菌性眼内炎临床治疗分析

目的探讨蜡样芽孢杆菌所致眼内炎的治疗方法。方法对2005至2008年我院确诊的5例（6只眼）外伤性蜡样芽孢杆菌性眼内炎,行角巩膜清创缝合＋晶状体玻璃体切除＋硅油充填术,联合广谱抗生素应用,回顾分析手术时间选择,药物应用对愈后的影响。结果 5例（6只眼）患者中,2只眼摘除眼球植入义眼,3只眼保留眼球者视力无光感,1只眼矫正视力0.1。结论对角巩膜穿通伤眼内异物合并感染者应行急诊晶状体玻璃体切除＋硅油充填术,眼内抗生素盥洗,术后广谱抗生素局部及全身应用,对蜡样芽孢杆菌性眼内炎治疗,应用万古霉素、氯林可、丁胺卡那霉素、环丙沙星等敏感药物,可提高治愈率。     

一起蜡样芽胞杆菌食物中毒分离株的毒力基因分析研究

目的 对红河州发生的一起蜡样芽孢杆菌食物中毒分离株进行毒力基因分析研究。方法 本次食物中毒从一位病人肛拭子标本和三种剩余食物中分离出4株蜡样芽孢杆菌,利用PCR检测分离株的腹泻型毒力基因:hbl(ACD)、nhe（ABC）、cytK、entFM、bceT 和呕吐型毒力基因:NRPS 。结果 病人（肛拭子）和剩余食物（火腿烩乳饼）分离株均携带有hbl(ACD)、nhe（ABC）、cytK、entFM、bceT 基因;剩余食物（虾）分离株携带有nhe（ABC）、entFM 基因;剩余食品（冰木瓜凉水）分离株携带有hbl(CD)、nhe（ABC）、cytK、entFM、bceT 基因;所有分离株均不携带有呕吐型毒力基因NRPS 。结论 本次食物中毒根据毒力基因检测结果,可以确定为由蜡样芽孢杆菌引起的腹泻型食物中毒。     

Enhanced vaccine antigen delivery by Salmonella using antibiotic-free operator–repressor titration-based plasmid stabilisation compared to chromosomal integration

Live attenuated bacteria provide the potential to replace traditional needle-based vaccination with an orally administered vaccine. The heterologous antigen gene is usually transformed as a multi-copy plasmid into the bacterial cell, but plasmids in live bacterial vaccine strains are often unstable, so an alternative approach is to integrate the single-copy antigen gene into the bacterial chromosome. We report a comparison between the chromosomally integrated and the plasmid-borne Bacillus anthracis protective antigen gene in live Salmonella enterica serovar Typhimurium, using the Operator–Repressor Titration (ORT) system to ensure stable plasmid maintenance. These studies demonstrate that the stabilised plasmid approach of gene expression produced greater amounts of antigenic protein, which in turn resulted in higher antibody responses and levels of protection in mice.     

首针乙肝疫苗及卡介苗接种分析

目的了解东营区产妇HbsAg筛查情况,新生儿乙肝疫苗及卡介苗在不同医院产科接种室的接种情况及影响因素。方法采取分层抽样方法,对市、区、个体三级医院出生的所有新生儿进行HbsAg筛查率及乙肝疫苗、卡介苗接种率调查。结果各类医院产科HbsAg筛查率及乙肝疫苗、卡介苗接种率差异明显。结论东营区不同级别的医院产科接种室首针乙肝疫苗及卡介苗接种工作开展较好,有效控制了结核病和乙型病毒性肝炎的发病率。     

Acute toxicity and cytotoxicity of Bacillus thuringiensis and Bacillus sphaericus strains on fish and mouse bone marrow

The insecticidal properties of delta-endotoxins from Bacillus thuringiensis (Bt) serotypes kurstaki and israelensis and crystal proteins of Bacillus sphaericus (Bs) serotype H5 have been used in insect control for decades. The availability of microbial toxins in biopesticides as well as in plants with incorporated protection has been increasing the concerns about biosafety. Acute toxicity to Danio rerio and cytotoxicity on mouse bone marrow cells and peripheral erythrocytes of Oreochromis niloticus were tested with Bt israelensis, Bt kurstaki and Bs H5 strains. The concentration and dose tested were 10⁶ and 10⁸ spores/ml, respectively. Neither lethality nor effects on mouse bone marrow were promoted by any strain. In necrosis–apoptosis study on peripheral erythrocytes of O. niloticus an increased frequency of necrotic cells caused by exposure to strains of B. thuringiensis was found. Exposure to B. sphaericus did not show cytotoxic effects in either tested system. None of the strains studied induced apoptosis in contrast with the chemical controls.     

整肠生中地衣芽孢杆菌对几种常见抗菌药物的体外敏感性

目的 研究整肠生(治疗肠炎及腹泻药)中地衣芽孢杆菌对几种常见抗菌药物的体外敏感性.方法 通过抑菌圈法及最低抑制浓度(MIC)法进行体外抗菌药物敏感性试验.结果 该菌种对青霉素等8种抗菌药物表现为耐药;对头孢哌酮等6种抗菌药物表现为中度;而对法罗培南等5种抗菌药物表现为敏感.结论 临床上,整肠生可与青霉素等10种抗菌药物共同使用,而不产生拮抗;但与法罗培南等9种抗菌药物共同使用时,会在不同程度上抑制其疗效.