Effect of vitamin E nutritional supplementation on the pathological changes induced in the ileum of rabbits by experimental infection with enteropathogenic Escherichia coli

A well-established rabbit model of enteropathogenic E. coli (EPEC) disease was used to examine whether vitamin E (VE) nutritional supplementation had an effect on the pathological changes induced in the bowel by EPEC. Quantitative methods were used to evaluate the influence of VE on bacterial colonization, intestinal mucosal architecture and inflammation, and intestinal epithelial proliferation and apoptosis. VE did not affect EPEC colonization and did not give significant protection against EPEC-induced changes and diarrhoea. Although VE had no effect on the EPEC-related increase of enterocyte apoptosis, it clearly contributed to an acceleration of epithelial cell proliferation in the ileal crypts. This finding may explain why ileal morphometry undertaken in this study showed that VE ameliorated somewhat the effects of EPEC on intestinal mucosal architecture. Quantitative studies on inflammatory cells in the intestinal mucosa revealed that VE nutritional supplementation resulted in an increased neutrophilic and mononuclear inflammatory cell response to EPEC infection, which did not contribute, however, to the clearance of infection.     

Effects of Schisandra chinensis Baillon (Schizandraceae) on lipopolysaccharide induced lung inflammation in mice

Aim of the study

This study was aimed to evaluate the neuroprotective and anti-aging activity of extracts in Caenorhabditis elegans from the roots and leaves of Damnacanthus officinarum Huang to provide the pharmacological basis in traditional medicine.

Materials and methods

Investigations on the neuroprotective and lifespan activity were carried out, which were observed by utilizing the following models: observing the worms’ chemosensory behavior test based on the aversion index in the assay plate, neuroprotective activity of nematode by evaluating the ASH neuron survival and lifespan test in C. elegans.

Results

It has been shown that the ethanol, n-butanol and aqueous extracts in the roots possessed significantly neuroprotective effect both in chemosensory behavior test and ASH neuron survival model. The same extracts in the leaves showed similar activities in two models, but have less potency revealing by the data. Four candidate extracts, possessing excellent neuroprotective activity, extend lifespan in C. elegans. The n-butanol extracts in the root part showed best efficacy among them.

Conclusion

The results show the n-butanol and aqueous extracts are the major pharmacological plant extracts. Moreover, the neuroprotective and lifespan-extension activity effects of root extracts are superior to leave extracts, supporting the traditional application of above-ground parts of DOH in treating various diseases associated with brain disorders and anti-aging.     

三黄汤对E.coli内ESBLs基因表达的干预性研究

目的:观察三黄汤水煎剂对E.coli细胞内编码ESBLs基因TEM,CTX-M,SHV,OXA以及编码膜外排泵蛋白AcrAB-TolC基因Acr-AB表达的干预效果,探讨中药对细菌耐药性逆转的可能性。方法:采集鉴定ESBLs阳性E.coli菌株30株,用试管二倍稀释法确定三黄汤的MIC(最低抑菌浓度),选取低于MIC的不同浓度在规定时间下培养耐药E.coli,测定不同浓度逆转效果和最佳逆转浓度,并以最佳逆转浓度培养24小时后提取菌体的总RNA进行RT-PCR,检测TEM,CTX-M,SHV,OXA,Acr-AB的表达量是否受到影响。结果:三黄汤水煎剂对ESBLs阳性大肠埃希菌最低抑菌浓度为0.2g/mL;对照组与用药组相比,OXAQ差异显著,有统计学意义(P<0.05),而OXAJ无统计学意义(P>0.05),5个基因中,编码OXA型ESBLs的基因表达量在干预前后有统计学意义(P<0.05)。结论:中药汤剂能通过抑制ESBLs阳性E.coli内ESBLs的活性和表达量,降低细菌耐药性,且其逆转作用与中药浓度有关;0.2 g/mL三黄汤对ESBLs阳性E.coli体内的ESBLs编码基因OXA有抑制作用,可使其表达量下降;尚未发现三黄汤对受试菌TEM,CTX-M,SHV,Acr-AB基因有明确的干预作用。     

Growth and Antioxidant System of <Emphasis Type="Italic">Escherichia coli</Emphasis> in Response to Microcystin-RR

Microcystins are a kind of cyclic hepatoxins produced by many species of cyanobacteria. The toxic effects of microcystins on animals and plants have been well studied. However, the reports about the effects of microcystins on microbial cells are very limited. In present paper, Escherichia coli was undertaken to determine the effect of microcystin-RR. These results suggested that microcystin-RR could prolong the growth of E. coli when exposed to high concentrations of microcystin-RR and cause the accumulation of ROS and induce the oxidant stress for a short time. The antioxidant system protects E. coli from oxidative damage.     

福建省非典型肠致病性大肠杆菌（aEPEC）的发现及某些分子特征的研究

目的2010年10月从一名死婴粪便标本中分离到非典型肠致病性大肠杆菌（aEPEC）,为福建省首次鉴定该病原菌。本研究的目的是了解该病原菌的特征,为进一步开展aEPEC的研究工作提供基础数据。方法包括常规的系统生化鉴定、血清学鉴定、药敏试验、PCR检测毒力基因分布、eaeA基因的测序分析。结果该菌株生化表现符合大肠埃希氏菌特征;现有的典型的EPEC血清型不能凝集;药敏实验结果提示对大部分的药物均敏感;毒力基因检测为eaeA+、bfp-、stx1-、stx2-、ehxA-、paa-;eaeA序列在NCBI上比对的结果均提示为大肠埃希氏菌（EHEC/EPEC）紧密素（intimin）的eaeA基因。结论根据常规实验、分子诊断及测序结果证实该病原菌为福建省首次鉴定的非典型肠致病性大肠杆菌（aEPEC）,同时我们需要进一步检测其它的毒力相关基因,探讨这些基因和该菌株致病力的关系。     

Non-pathogenic commensal Escherichia coli bacteria can inhibit degranulation of mast cells

Background:  The mast cell's (MC) ability to rapidly release presynthesized mediators allows it to play a critical role in the immune system's first-line response to pathogens. Although recent research has illuminated the role of MCs in bacterial infection, little is known about how non-pathogenic bacteria influence MC responses.
Objective:  To characterize the influence of non-pathogenic Escherichia coli bacteria on MCs.
Results:  High concentrations of live E. coli strongly down-modulated the degranulation of murine peritoneal MCs under all activator conditions. Bacteria did not induce MC degranulation by themselves, and staining of MCs showed they were still entirely viable. Dead bacteria and bacterial supernatant had no effect on MC degranulation. Ex vivo experiments confirmed that E. coli exposure down-modulates subsequently induced MC degranulation and that this effect lasts for up to a few days after exposure.
Conclusion:  Our results show that high doses of non-pathogenic E. coli bacteria can function as a strong, direct inhibitor of MC degranulation. This suggests a possible basis for future antiallergic treatment or prophylaxis with commensal bacteria, i.e. probiotics.     

某碘伏消毒液的杀菌效果试验观察

目的了解某碘伏消毒液杀菌效果及相关性能,为正确、合理、有效地使用消毒剂提供科学依据。方法采用悬液定量杀菌试验方法进行了实验室检测。结果以含50mg/L有效碘的碘伏消毒液对金黄色葡萄球菌和大肠杆菌作用3min,杀灭对数值〉5.00,对白色念珠菌作用5min,杀灭对数值〉5.00;碘伏消毒液在37℃存放3个月,有效碘含量下降率为7.84%。结论某碘伏消毒液对细菌繁殖体和真菌都具有很强的杀灭效果,稳定性良好。     

2009年安阳市部分食品中污染物、食源性致病菌监测

[目的]了解安阳市销售环节食品的污染状况,为我市食品安全风险评估,预防控制和调查处理食品安全事故提供科学依据。[方法]2009年8～10月,在市区及下辖滑县、林县市场上随机采取10类404份食品,分别进行铅、镉、铝3种金属污染物及大肠菌群、沙门氏菌、副溶血性弧菌、大肠埃希菌0157、单核细胞增生李斯特氏菌、金黄色葡萄球菌6种食源性致病菌监测。[结果]在面粉、大米中铅污染严重,超标率分别为57．50％、40．00％;镉在猪肾、猪肉和淡水鱼超标率分别为45．00％、10．00％、2．50％;铝在油炸食品、鲜海蜇中污染严重,超标率分别为60．00％、100．00％。分别检出沙门菌、单增李斯特菌、副溶血性弧菌8株、7株、4株,检出率分别为11．11％、15．20％、40．00％,首次检出1株大肠杆菌O157：H7。[结论]铅、镉、铝在我市部分食品中污染严重,食源性致病菌在生鸡肉、鲜鱼、生猪肉及部分即食的熟肉制品中污染的几率较高,我市食品安全存在隐患。     

浙江省肠出血性大肠杆菌O_(157)∶H_7动物宿主带菌情况调查

目的了解浙江省肠出血性大肠杆菌O157∶H7在动物宿主中的带菌情况。方法采集浙江省2006-2008年监测点的动物粪便进行病原菌培养和毒力基因及耐药性检测。结果共采集动物粪便3915份,检出肠出血性大肠杆菌O157∶H7阳性20份,带菌率为0.51%,其中以羊和牛的带菌率最高,分别为1.46%和1.43%,散养动物带菌率高于圈养动物(χ2=5.771,P=0.016)。阳性菌株stx2、hly和eaeA3种毒力基因均呈阳性,stxl均呈阴性。对红霉素和利福平耐药,耐药率达90%以上,对其他受试抗生素敏感。结论浙江省动物宿主有一定的带菌率,且菌株具有毒力基因,散养动物的带菌率高于圈养动物,应进一步加强监测,防止O157∶H7引起人群的爆发流行。     

大肠埃希菌在尿路感染的分布及耐药分析

目的分析大肠埃希菌在尿路感染中的分布特点及耐药现状,为临床合理用药提供参考。方法采用法国生物梅里埃公司VITEK2-Compact微生物分析仪进行细菌鉴定和药敏分析。对2008年4月—2010年4月住院及门诊尿路感染患者尿培养分离出的652例大肠埃希菌进行药敏分析,同时进行ESBLs检测。结果尿路感染大肠埃希菌中产ESBLs大肠埃希菌检出率为38%。药敏结果显示,大肠埃希菌对丁胺卡那霉素、呋喃妥因、美洛培南、亚胺培南等耐药率低,对青霉素类和环丙沙星、左旋氧氟沙星及庆大霉素耐药率大于60%。ESBLs阳性耐药率明显高于ESBLs阴性。病房标本分离菌株耐药率明显高于门诊。结论尿路感染中大肠埃希菌的耐药严重,尤是ESBLs阳性菌株,应加强耐药监测,指导临床合理用药,减缓耐药菌株出现。