药品微生物限度检查中大肠杆菌检查特例

本文对实验工作中发现的一例疑似大肠杆菌的菌株作了常规生化试验和ＭＵＧ－Ｉｎｄｏｌｅ快速检验，结果发现：该菌株在标准规定的检验时间内观查结果则安全符合非典型大肠杆菌的生化反应，为检出大肠杆菌，但ＭＵＧ－Ｉｎｄｏｌｅ试验却均为阴性。若将柠檬酸利用试验时间延至１４４小时，则生化反应变为－＋－＋－。     

药品微生物限度检查中大肠杆菌检查特例

目的对疑似大肠杆菌的菌株进行检测.方法MUG-Indole法和药典法.结果MUG-Indole法简便、快速、准确,优于药典法.结论检查大肠菌群比检查大肠杆菌更能说明药品中污染控制菌的情况.     

快速检定大肠杆菌法在医院制剂质控中的应用

目的:对我院自制的20种内服制剂做了大肠杆菌的快速检定.方法:用MUG-Indole(M-I)法对制剂中的大肠杆菌进行检定.结果:自然污染的20种制剂中16种样品M-I结果为阴性,4种样品M-I结果不一致;20种制剂的阳性对照试验结果均显阳性.结论:16种制剂对M-I法均无影响,4种制剂M-I结果不一致,需进一步做IMViC生化试验检定.     

用MUG-Indole法及部颁法对大肠杆菌比较鉴定的研究

对16种药品36批次进行大肠杆菌部颁法及MUG-Indole法检验比较,证明两法相符率高,且MUG-Indole法具有快速、简便、准确、无主观性的优点.     

用MUG-Indole法及部颁法对大肠杆菌比较鉴定的研究

对16种药品36批次进行大肠杆菌部颁法及MUG-Indole法检验比较,证明两法相符率高,且MUG-Indole法具有快速、简便、准确、无主观性的优点.     

五大连池矿泥卫生学研究

由五大连池矿泥制成释释液,利用平皿法检出天然矿泥中杂菌总数分别为１０５０个／ｇ（Ｉ＃）。１６９０个／ｇ（Ⅱ＃）。对杂蓝中镜检呈短杆菌进一步作大肠杆菌定性鉴别试验,在ＩＭＶＩＣ特定生化反应中呈出为“－、－、＋、＋”,主明天然矿泥不存有大肠杆菌,未受到人畜粪便的污染。对杂菌中发现的球菌做金葡萄球菌定性鉴别的甘露醇发酵试验,Ⅰ＃、Ⅱ＃矿泥样品培养基未发现颜色改变,主明天然矿泥中亦不存在金黄葡萄球菌做金黄     

M—I法与部颁法检定药品中污染大肠杆菌的实验研究

用Ｍ－Ｉ法与部颁法考察了３５种药品人工污染大肠杆菌的存活及变异情况，结果表明：Ｍ－Ｉ法与部颁法的检出率，灵敏度，准确性基本相同。Ｍ－Ｉ法在增菌后２４ｈ内能检出大肠杆菌，方法简便，省时，省力，省物，结果容易观察判断，不需确证试验，并能检出ＩＭＶｉＣ试验为＋＋－＋的大肠杆菌，故Ｍ－Ｉ法的结果及判定标准更具有卫生学意义。     

MUG-Indole法快速检定大肠杆菌方法介绍

本文用MUG-Indole法(快速检定大肠杆菌新方法,以下简称M-I法)与药典法对20个供试品进行对比实验,实验结果两种方法基本一致,且M-I法在时间性、准确性、灵敏性、特异性等方面明显优于药典法。     

一株三糖铁反应似志贺菌属血清学交叉的产毒型大肠埃希菌

目的对实验中发现的一株与鲍氏志贺菌属诊断血清1~6型发生凝集反应的低活性肠产毒性大肠埃希菌(ETEC)进行较详细的生化和血清学鉴定,为今后相关细菌鉴定工作提供参考。方法参考GB/T4789.5-2003和GB/T4789.6-2003检验。结果对分离到的疑似志贺菌经全面生化反应及血清学鉴定证实为1株肠产毒性大肠埃希菌O6:K15。结论在肠道致病菌的鉴定中,即使是血清学反应符合的菌株也应结合生化检验结果做出判断。     

实验室药品无菌检查能力的验证及结果分析

目的：通过无菌检查能力验证考查实验室无菌检查水平,提升实验室药品无菌检查能力和实验室管理能力。方法：对3次能力验证共计12个样品,分别采用直接接种法和薄膜过滤法进行无菌检查;采用16S核糖体DNA(r DNA)序列分析法和全自动生化鉴定仪对其中4个阳性结果的16株分离菌株、日常监测发现的29株环境微生物进行鉴定。结果：16株分离菌株分别为金黄色葡萄球菌和白色念珠菌,与29株环境菌不同,结合实验过程的回顾性判断,确认无菌检测结果有菌生长的样品为样品中有微生物污染。12个样品的检验结果为4个有菌生长,8个无菌生长,均为满意结果。结论：实验室可以使用16S rDNA序列分析法和全自动生化鉴定仪对检验发现的污染菌进行鉴定。本研究中无菌检查能力验证的结果分析和能力验证的实施过程的回顾,有利于提高实验室检测结果的准确性和有效性。     

MUG─Indole快速检定大肠杆菌方法研究

本文报道用ＭＵＧ－Ｉｎｄｏｌｅ检定大肠杆菌方法，在２４ｈ内能将９４％～９７％的大肠杆菌检出。对ＭＵＧ阳性、Ｉｎｄｏｌｅ阴性或ＭＵＧ阴性、Ｉｎｄｏｌｅ阳性的菌株，辅以ＥＭＢ琼脂或麦康凯琼脂平板分离，挑选可疑菌落，做ＩＭＶｉＣ试验，使假阳性和假阴性降到最低水平。本法比传统的生化试验检定大肠杆菌法快速、简便、准确、无主观性。     

Substrate recognition by a family of uracil-DNA glycosylases: UNG,MUG, and TDG

In response to continuous hydrolytic and oxidative DNA damage, cells of all organisms have a complex network of repair systems that recognize, remove, and rebuild the injured sites. Damaged pyrimidines are generally removed by glycosylases that must scan the entire genome to locate lesions with sufficient fidelity to selectively remove the damage without inadvertent removal of normal bases. We report here studies conducted with a series of base analogues designed to test mechanisms of base recognition suggested by structural studies of glycosylase complexes. The oligonucleotide series examined here includes 5-halouracils with increasing substituent size and purine analogues placed opposite the target uracil with hydrogen, amino, and keto substituents in the 2- and 6-positions. The glycosylases studied here include Escherichia coli uracil-DNA glycosylase (UNG), E. coli mismatch uracil-DNA glycosylase (MUG), and the Methanobacterium thermoautotrophicum mismatch thymine-DNA glycosylase (TDG). The results of this study suggest that these glycosylases utilize several strategies for base identification, including (1) steric limitations on the size of the 5-substituent, (2) electronic-inductive properties of the 5-substituent, (3) reduced thermal stability of mispairs, and (4) specific functional groups on the purine base in the opposing strand. Contrary to predictions based upon the crystal structure, the preference of MUG for mispaired uracil over thymine is not based upon steric exclusion. Furthermore, the preference for mispaired uracil over uracil paired with adenine is more likely due to reduced thermal stability as opposed to specific recognition of the mispaired guanine. On the other hand, TDG, which exhibits modest discrimination among various pyrimidines, shows strong interactions with functional groups present on the purine opposite the target pyrimidine. These results provide new insights into the mechanisms of base selection by DNA repair glycosylases.     

Inhibitory effect of probiotic Escherichia coli strain Nissle 1917 on adhesion to and invasion of intestinal epithelial cells by adherent-invasive E. coli strains isolated from patients with Crohn's disease

BACKGROUND: Pathogenic adherent-invasive Escherichia coli have been isolated from ileal lesions of Crohn's disease. AIM: : To investigate the non-pathogenic E. coli strain Nissle 1917 (Mutaflor) as possible maintenance therapy in inflammatory bowel disease by testing its ability to prevent adherent-invasive E. coli strains from adhering to and invading human intestinal epithelial cells in vitro. METHODS: Bacterial adhesion to and invasion of intestinal epithelial cells (Intestine-407) were assessed by counting the colony-forming units. The inhibitory effect of E. coli Nissle 1917 was determined after co-incubation with adherent-invasive E. coli strains or after pre-incubation of the intestinal epithelial cells with this probiotic strain prior to infection with adherent-invasive E. coli strains. RESULTS: Strain Nissle 1917 exhibited dose- and time-dependent adherence to intestinal epithelial cells and inhibited the adhesion and invasion of various adherent-invasive E. coli strains. In co-infection experiments, the inhibitory effect on adherent-invasive E. coli adhesion reached 78-99.9%. Pre-incubation of intestinal epithelial cells with strain Nissle 1917 reduced adherent-invasive E. coli adhesion by 97.2-99.9%. The inhibitory effect on adherent-invasive E. coli invasion paralleled that on adhesion. CONCLUSION: As strong and significant inhibitory effects on adherent-invasive E. coli adhesion and invasion were observed in co-infection and pre-infection experiments, E. coli Nissle 1917 could be efficient for preventive or curative probiotic therapy in patients with Crohn's disease.     

Production of ansamycin polyketide precursors in Escherichia coli

For the heterologous production of ansamycin polyketides such as rifamycin and geldanamycin in Escherichia coli, a number of unusual but important tools must be engineered into the bacterium. Here we demonstrate efficient production of the starter unit 3-amino-5-hydroxybenzoic acid (AHBA) and the methoxymalonyl extender unit in E. coli. Previous work has demonstrated the production of the ansamycin starter unit AHBA in E. coli in low yield. It was shown that the low yield is primarily due to acetylation of AHBA into N-acetyl-AHBA. Three methods for minimizing this side reaction were evaluated. First, a putative N-arylamine-acetyltransferase (NAT) was deleted from the E. coli chromosome, although this did not alter N-acetyl-AHBA production. Next, E. coli grown in media devoid of glucose yielded a nearly equal mixture of AHBA and N-acetyl-AHBA. Lastly, the NAT inhibitor glycyrrhizic acid was shown to further inhibit the acetylation reaction. The entire set of genes for synthesizing the methoxymalonyl extender unit was transferred from the geldanamycin producer Streptomyces hygroscopicus into E. coli. The pathway specific ACP isolated from the resulting recombinant strain was found to predominantly occur as methyoxymalonyl-ACP. Together, these findings set the stage for engineered biosynthesis of ansamycin polyketides in E. coli.     

Anthraquinone-containing compound in rhubarb prevents indole production via functional changes in gut microbiota

Journal of Natural Medicines - Indole is produced from dietary tryptophan by tryptophanase in intestinal bacteria, such as Escherichia coli. In the liver, indole is converted into indoxyl sulfate,...     

Susceptibilities of uropathogenic bacteria to ampicillin, cefazolin, cefmetazole and gentamicin. Nine-year survey of changing patterns of susceptibilities

We analyzed antibiotic susceptibilities of urinary isolates of Escherichia coli, Klebsiella spp., Proteus mirabilis, and Indole (+) Proteus group to ampicillin (ABPC), cefazolin (CEZ), cefmetazole (CMZ) and gentamicin (GM) in 69 laboratories in 1988 and also studied changing patterns of susceptibilities from 1980 to 1988. Minimal inhibitory concentrations were determined using the agar dilution method (MUELLER-HINTON agar, BBL) with inoculation of 10(6) cfu/ml of bacteria. Ninety to 99% of the strains of E. coli, Klebsiella spp. and P. mirabilis were inhibited at a concentration of 6.25 micrograms/ml of CEZ and CMZ and of 1.56 micrograms/ml of GM. Approximately 80% of the strains of Indole (+) Proteus group were inhibited at concentrations of 6.25 micrograms/ml of CMZ and of 1.56 micrograms/ml of GM. However, resistance to ABPC and CEZ was high, with 83% and 81% of the strains being not inhibited at a concentration of 50 micrograms/ml of ABPC and CEZ, respectively. No significant changes in susceptibilities of the 4 bacteria to the above 4 antibiotics were observed over the 9 year period. No increase was found in the incidence of the resistant strains of the 4 bacteria to CMZ and GM, nor of E. coli and Klebsiella spp. to CEZ.     

Synergism of cephalosporins at subinhibitory concentrations and polymorphonuclear leukocytes on phagocytic killing of Escherichia coli and its mode of action

The interactions between subinhibitory concentrations of cephalosporins and polymorphonuclear leukocytes in the killing of a strain of Escherichia coli are described and an attempt is made to define the responsible mechanism. Ceftizoxime was the most potent agent tested. Pretreatment of the E. coli strain with subinhibitory concentrations of ceftizoxime increased the susceptibility to both; phagocytic killing activity of the polymorphonuclear leukocytes and bactericidal activities of the oxygen metabolites and the granule extracts. A most interesting result was the increased susceptibility of the ceftizoxime-treated E. coli to killing by beta-glucuronidase which normally is not bactericidal. It is suggested that the augmented killing could be due to bacteriolysis by beta-glucuronidase.     

Adenylylation of trospectomycin by crude enzyme preparations from Escherichia coli

Employing osmotically shocked lysate of a spectinomycin resistant strain of Escherichia coli, trospectomycin, a new alkylspectinomycin, was adenylylated in the presence of adenosine 5'-triphosphate and magnesium ion. A highly resistant strain of E. coli was obtained by transforming a laboratory strain with a newly constructed plasmid consisting of pBR322 and a determinant for spectinomycin resistance originally found on a low copy number plasmid in E. coli strain NR79. The biologically inactive adenylylated trospectomycin was found to be trospectomycin 6-(5'-adenylate).     

一种新的快速简便的抗肿瘤药物筛选模型

本研究利用DNA修复缺陷的大肠埃希氏菌343/591和正常的大肠埃希氏菌343/636的差异性DNA修复特性,建立了液体悬浮法和琼脂固体筛选方法,用于抗肿瘤药物的筛选。这两种方法简单易行,其中琼脂固体筛选方法与抗生素生物鉴定杯碟法一样简单,适合于大量筛选各种来源的抗肿瘤药物。     

小儿急性阑尾炎细菌学检查及药敏试验的回顾

小儿急性阑尾炎细菌学检查及药敏试验的回顾李岚蔡威陈方张宛陵施诚仁金惠明（上海第二医科大学附属新华医院上海２０００９２）急性阑尾炎是小儿外科常见疾病，病情往往比成人严重，穿孔、腹膜炎的发生率较高，术后正确选用抗菌药物治疗以及防止术后并发症非常重要。引起...