加替沙星对小鼠肠道菌群的影响

目的 了解加替沙星正常剂量用药和非正常剂量用药方式对小鼠肠道菌群的影响.方法 24只昆明小鼠随机分为3组,每组8只,对照组只灌胃生理盐水,另外2组分别按正常剂量和正常剂量的一半给小鼠灌胃加替沙星溶液,7 d后无菌采取小鼠粪便,观察各组小鼠粪便中双歧杆菌、类杆菌、乳酸杆菌、大肠埃希菌及肠球菌数量.结果 加替沙星灌胃7 d后,与给药前相比,肠杆菌和肠球菌药敏结果无明显变化.灌胃前后肠杆菌对CIP、LEV、GAT、AM、CRO、AMK、NOR均敏感,肠球菌对AM、LEV、VA、GAT均敏感,对NOR、CIP、CRO敏感性不同.2种用药方式可导致大肠埃希菌数量显著减少(P＜0.05),肠球菌数量稍有增加(P＞0.05).而双歧杆菌、乳酸杆菌和类杆菌数量无明显变化(P＞0.05).结论 加替沙星2种用药方式短时期对肠道菌群影响不大(肠杆菌除外),不易产生耐药性.其杀灭肠杆菌的作用远大于对厌氧菌的作用.     

残留剂量头孢曲松长期作用对SPF级Balb/c小鼠肠道菌群的影响

目的研究残留剂量头孢曲松的长期作用对SPF级Balb/c小鼠肠道菌群的影响。方法通过随机饮水方式,连续45 d分别给予SPF小鼠3个浓度的低剂量头孢曲松,模拟残留剂量抗生素的持续作用,活菌计数研究菌群数量变化。结果 300μg/ml及30μg/ml头孢曲松水溶液持续作用,小鼠肠道菌群厌氧总菌、乳杆菌和肠杆菌数量均出现先降后升的趋势,而肠杆菌数量异常增殖,双歧杆菌数量显著减少(P0.01)且无法恢复,肠球菌无显著变化(P0.05);3μg/ml头孢曲松处理后小鼠肠道肠杆菌数量显著升高,其余检测细菌数量无显著影响(P0.05)。结论 300、30及3μg/ml头孢曲松水溶液持续处理45 d均会导致小鼠肠道菌群失调,菌群失调程度与头孢曲松浓度密切相关。     

双歧杆菌对实验性肠梗阻肠道G^—菌及血内毒素影响的研究

本实验采用大白鼠的急性、单纯性、机械性肠梗阻模型,将80只大鼠随机分成5组:正常对照组、梗阻未治疗组、新霉素治疗组、甲哨唑治疗组、双歧杆菌治疗组。分别将各制刑直接肠道给药。24h后,对梗阻近端回肠末段的肠杆菌、双歧杆菌进行定性及定量检测,并同时测定各组门静脉血内毒素值。结果表明,新霉素及甲哨唑治疗组双歧杆菌明显减少(P<0.01);门静脉血内毒素明显升高(P<0.01),达到未治疗组的水平(P<0.05)。新霉素治疗组肠杆菌明显减少(P<0.01),甲哨唑治疗组肠杆菌明显增加(P<0.01),达到未治疗组的水平(P>0.05)。未治疗组肠杆菌及门静脉血内毒素明显增加(P<0.01),双歧杆菌无明显减少。双歧杆菌治疗组双歧杆菌明显增加(P<0.01),肠杆菌保持在正常水平(P>0.05),门静脉血内毒素明显低于未治疗组和各抗生素治疗组(P<0.01)。本实验说明,急性肠梗阻时,肠道内肠杆菌数量及门静脉血内毒素可明显升高;外源性双歧杆菌在肠道内能抑制肠杆菌,降低门静脉血内毒素水平;新霉素及甲哨唑能引起肠道菌群紊乱,促使血内毒素过度升高。因此,利用双歧杆菌制剂作为急性肠梗阻治疗申的辅助用药,具有一定实际意义。     

2009-2011年胆石症患者胆汁肠球菌菌群分布及菌种耐药性变迁

目的 了解2009年1月年2011年12月胆石症患者胆汁中肠球菌的分布及菌种耐药性变迁,指导临床合理应用抗菌药物.方法 采用法国生物梅里埃公司生产的VITEK-2细菌分析仪对胆汁标本中分离的肠球菌做鉴定及药敏试验.结果 2009年1月至2010年6月共分离到74株肠球菌;2010年7月至2011年12月共分离到115株肠球菌,排在前两位的均为粪肠球菌和屎肠球菌.药敏结果显示粪肠球菌对除红霉素和喹努普汀/达福普汀外的其他抗菌药物具有较高的抑菌活性;屎肠球菌对除喹努普汀/达福普汀、利奈唑胺、万古霉素外的其他抗菌药物具有较高的耐药率;首次检测到耐利奈唑胺的肠球菌.结论 胆石症患者胆汁中肠球菌感染以粪肠球菌和屎肠球菌为主,且多种细菌对抗菌药物均有不同程度的耐药,因此加强细菌耐药监测对临床合理使用抗菌药物有重要的参考意义.     

肠道菌群正常参考值的检测

目的定性定量检测并比较杭州地区健康青壮年及老年人群肠道主要菌群(双歧杆菌属、类杆菌属、消化链球菌属、产气荚膜梭菌、乳杆菌属、肠杆菌科、肠球菌属及酵母菌等)的正常参考值,同时计算并比较双歧杆菌属细菌数量与肠杆菌科细菌数量的对数值比值(B/E值).方法采用光冈法 .结果老年组肠道双歧杆菌数量及B/E值较青壮年组均显著减少(P＜0.05, P＜0.001);消化链球菌、肠杆菌科及肠球菌细菌数量显著增加(P＜0.01,P ＜0 .001,P＜0.05).结论在获得肠道菌群正常参考值的同时,发现随着年龄的增加,老年人肠道双歧杆菌数量明显减少,肠杆菌科及肠球菌细菌数量显著增加.     

抑郁症人群肠道微生物群落结构与功能探讨

目的了解抑郁症人群肠道主要微生物群落情况,探讨在机体精神心理异常状态下肠道内微生态平衡特点,从而为研究抑郁症人群及相关精神心理疾患人群的防治新策略提供数据资料。方法设抑郁症患者研究组和健康对照组,采用日本光冈法定性定量检测肠道乳杆菌属、双歧杆菌属、类杆菌属、消化链球菌属、肠球菌属、产气荚膜梭菌、肠杆菌科及酵母菌的菌群值,计算和比较双歧杆菌属细菌数量与肠杆菌科细菌数量的对数值比值(B/E值)。结果与健康人对照组比较,抑郁症人群研究组肠道乳杆菌和双歧杆菌数量显著降低(P0.01);B/E值显著减少(P0.01);肠杆菌科细菌、肠球菌数量显著增加(P0.01,P0.05)。结论抑郁症人群肠道乳杆菌和双歧杆菌数量显著减少,肠杆菌科及肠球菌细菌数量显著增加,益生菌群与肠杆菌科结构发生改变,推测抑郁症的发生,有可能通过肠-脑轴的联系,使大脑情感中枢功能紊乱与肠道菌群微生态平衡失调的相互作用有关。     

更年期综合征人体肠道微生物群落结构研究

目的定性定量检测更年期综合征个体肠道微生物群落,探讨该状态中的人群肠道内微生态平衡状态及其特点,从而为研究更年期综合征人群的防治新策略提供数据资料。方法设患更年期综合征妇女研究组和相近年龄同性别的健康妇女对照组,采用光冈法检测相关肠道菌群(双歧杆菌属、乳杆菌属、类杆菌属、产气荚膜梭菌、消化链球菌属、肠杆菌科、肠球菌属及酵母菌)的菌群值,同时计算和比较双歧杆菌属细菌数量与肠杆菌科细菌数量的对数值比值(B/E值)。结果与相似年龄同性别的健康人群对照组比较,更年期综合征人群研究组肠道双歧杆菌数量显著降低(P0.01);B/E值较显著减少(P0.01);肠杆菌科细菌、消化链球菌、肠球菌数量显著增加(P0.01,P0.01,P0.05)。结论更年期综合征人群肠道双歧杆菌数量显著减少,肠杆菌科及肠球菌细菌数量显著增加,益生菌群与肠杆菌科结构发生改变,可能更年期综合征人群由于神经内分泌失调等健康状态的下降,引起肠道有益菌群与腐败菌比例发生变化,从而引起肠道微生态失调。     

甲硝哒唑对脆弱类杆菌作用机理的研究

采用同位素标记前体体外掺入技术和透射电镜观察方法从DNA. RNA及蛋白质水平上进行了甲硝哒唑对脆弱类杆菌作用机理研究。实验表明:甲硝哒唑几乎能完全抑制~3H-TdR掺入脆弱类杆菌,对~3H-亮氨酸的掺入也具明显的抑制作用,未观察到对RNA合成的影响。透射电镜下观察到,随着甲硝哒唑浓度增加,菌体形态发生明显的改变。     

抗生素对BALB/C小鼠免疫机制的影响

本文给普通BALB/C小鼠口服不同剂量的链霉素、新霉素干扰动物肠道菌群平衡状态,初步研究了肠道菌群平衡紊乱对动物迟发型超敏反应、脾脏抗体形成细胞数、外周血白细胞化功能、腹腔巨噬细胞吞噬活性的影响,以初步探讨普通动物中正常菌群与免疫机制间的微生态关系。结果表明,口服两种抗生素破坏动物正常菌群平衡均可导致机体免疫机能水平降低;免疫机能降低程度与抗生素抗菌谱、药物剂量及用药时间有密切关系。提示,口服抗生素引起机体肠道正常菌群平衡紊乱是导致机体免疫机能下降的重要原因;正常菌群与机体保持稳定的平衡状态对机体免疫机能的正常发挥是必不可少的。     

甲硝哒唑与庆大霉素联合治疗厌氧菌与兼性菌混合感染的动物实验研究

厌氧菌与兼性菌的混合感染及其治疗是目前临床上感染性疾病和抗生素治疗研究领域内的重要问题之一,本文对小鼠混合感染的动物模型甲硝哒唑与庆大霉素治疗结果显示:当脆弱类杆菌10~9CFU/ml大肠杆菌10~8CFU/ml混合感染小鼠6h后,单用甲硝哒唑治疗死亡率为9/10,脓肿率为1/10;单用庆大霉素组死亡率2/10,脓肿率为10/10;两药联用死亡率为2/10,无脓肿发生。两药联用的治疗比较:即时组基本同6h组,而12h开始治疗组死亡率达6/10。脓肿率4/6。提示应及早联合用药以阻断细菌的协同致病作用,控制感染。     

基于ERIC-PCR技术研究酪蛋白糖巨肽对小鼠肠道菌群结构的影响

目的了解酪蛋白糖巨肽(CGMP)对小鼠肠道中微生物群落结构及其动态变化的影响。方法采用ER IC-PCR技术分析鉴定在灌胃小鼠CGMP期间其肠道菌群结构的变化情况。在实验的第0、3、5、7、10、15和21天(灌胃停止后1周)分别提取对照组和CGMP组小鼠粪便总DNA,以此为模板进行PCR反应,获得肠道微生物群落的ER IC-PCR指纹图谱。结果小鼠个体在一段时间内微生物群落演替不明显,群落相似性较高。对照组小鼠肠道菌群多样性指数范围为1.75±0.06,CGMP组多样性指数范围为1.89±0.04,二者之间差异有统计学意义。结论小鼠肠道内的微生物群落非常丰富,普遍存在共有的优势菌群,且优势菌群的群落结构较为稳定;CGMP能够显著增加小鼠肠道菌群的多样性;聚类分析结果显示:对照组小鼠个体在不同时间的肠道菌群结构相似性较高,且ER IC-PCR指纹图谱没有明显的规律;CGMP组小鼠个体的ER IC-PCR指纹图谱被明显地分成2个亚族,说明小鼠灌胃CGMP 3~5 d后,其肠道菌群的群落结构开始发生明显变化。     

PCR-DGGE技术评价抗生素诱导的肠道菌群失调

目的 利用PCR-DGGE技术结合活菌计数评价抗生素引起的肠道菌群失调.方法 SPF级BALB/c雌性小鼠连续4 d灌胃头孢曲松溶液125 mg/ml,0.4 ml/d,运用基于细菌16S DNA的PCR-DGGE技术结合活菌计数分析小鼠肠道菌群变化.结果 活菌计数结果与PCR-DGGE图谱显示,头孢曲松处理3 d后小鼠肠道菌群出现严重失调.结论 PCR-DGGE技术可直观而灵敏地显示抗生素处理过程中肠道菌群的动态变化,适用于评价抗生素引起的肠道菌群失调.     

SPF级KM小鼠与BALB/c小鼠肠道总菌多样性的比较

目的分析SPF级封闭群KM小鼠及近交系BALB/c小鼠的肠道菌群总菌多样性,比较两个不同遗传背景肠道总菌的丰富度、Shannon-Wiener指数和均匀度。方法收集SPF级KM小鼠和BALB/c小鼠新鲜粪便,提取粪便总菌DNA,用基于细菌16S rDNA序列的变性梯度凝胶电泳(PCR-DGGE)分析粪便总菌多样性。结果 SPF级KM小鼠及BALB/c小鼠粪便总菌多样性差异无统计学意义(P0.05),品系内不同性别之间粪便总菌多样性差异亦无统计学意义(P0.05)。结论选择SPF级小鼠进行微生态学相关研究时,封闭群KM小鼠及近交系BALB/c小鼠均可作为选择对象,同时可忽略菌群的性别差异。     

Effects of dietary antibiotics on intestinal microflora in broiler chickens

Changes were examined in the intestinal microflora in broiler chickens fed a diet containing antibiotics to obtain fundamental information on the mechanisms of beneficial effect of the antibiotics upon livestock production. Three antibiotics (colistin, bacitracin, and enramycin) were employed as feed additives. Experiments were conducted with broiler chickens in two ways. In one way dietary antibiotics were fed continually at levels approved for use as feed additives for a long term. In the other they were fed the same antibiotics for a short term. Significant changes in microflora were observed mainly in such bacterial groups as aerobic bacteria and Lactobacillus. In the long term administration, three possible modes of variance in the bacterial flora were postulated: Changes directly related to the antibacterial spectrum of antibiotics. Antagonistic changes related to an ecological balance in the bacterial flora. Changes in quantitative balance of bacteria constituting each bacterial group. The change in the intestinal microflora during administration of the antibiotic diet was expressed as a complex form of these transition modes. In the short term administration, it was demonstrated that the effect of the antibiotic diet lingered even 7 days after administration. This suggests that antibiotics used as feed additives may possibly affect the stability of the intestinal microflora.     

Bacteriology of the oral cavity of BALB/c mice

To be used as a model in dental research, an animal must fulfil experimental needs and information on the composition and variation of its oral flora must be available. Only limited data are available on the indigenous oral bacterial flora of BALB/c mice. In this work, a total of 671 isolates from different sites (saliva, tongue, teeth, and mucosa) of the oral cavity of BALB/c mice were identified. Only 18 different species were isolated, which indicates the relative simplicity of the flora. The predominant species of the total cultivable flora were "Lactobacillus murinus" (38%), Staphylococcus aureus (37%), Streptococcus faecalis (8%), Staphylococcus sciuri (4%), and Escherichia coli (3%). The other species each represent less than 2% of the flora. "Lactobacillus murinus" is found in greater proportion on mucosa than in the other sites, Staph. aureus predominates in saliva, and Strep. faecalis was found in greater proportion in tooth samples. Statistical analyses, using the minimum percentage of similarity, indicate that there is some variation among the microflora of different mice but that this difference is smaller for mice from the same lot. These results set the basis for the study of the variations of the indigenous oral microflora of BALB/c mice under different conditions.     

Impact of Bifidobacterium longum on human fecal microflora.

The effects of Bifidobacterium longum feedings for five weeks on the fecal microflora, water contents, pH values, ammonia concentration, and beta-glucuronidase activity were investigated in five healthy human volunteers. Although numbers of major bacterial groups of the fecal microflora were not changed by the bifidobacteria feedings, a remarkably decreasing number of lecithinase-negative clostridia was observed. The percentage of lecithinase-negative clostridia and bacteroides to the total bacterial numbers isolated were decreased during the feedings and numbers of C. paraputrificum and C. innocuum were reduced. A significant reduction of fecal pH values for the last week of the feeding was observed. Ammonia concentration and beta-glucuronidase activity in the feces during the feedings were significantly lower than those before or after the feedings. The oral supplement of B. longum may be introduced to improve the fecal properties such as fecal ammonia concentration and beta-glucuronidase activity, but not the composition of fecal flora.     

Effect of somatotropic hormone on autoimmune responses induced in mice of different genotypes by syngenous heated erythrocytes]

A single administration of 1 X 10(9) heated erythrocytes to C57BL and BALB/c mice caused on the 13th day the appearance of antierythrocytic autoantibodies, an increase in the weight of the lymphoid organs, and lymphoreticular hyperplasia. These changes were more pronounced in BALB/c mice. During the development of autoimmune reactions the changes in the number of E- and EAC-rosette-forming cells in the thymus and spleen and in the immune response to the sheep erythrocyte immunization and E. coli endotoxin were revealed; distinct strain differences were observed. Daily somatotropic hormone administration (5 mg/kg of body weight) for 10 days decreased the degree of the autoimmune reactions development in mice of both strains. Its action was more expressed in BALB/c mice.     

Transfer of the cecal flora of the hamster to the germfree C3H mouse: use of this model to study the flora of the anti-Clostridium difficile barrier

The purpose of this work was the research and development of an experimental model to study anti-Clostridium difficile caecal microflora in the hamster. First the existence of this "barrier" was verified in conventional hamsters. Then, the caecal flora from these animals was orally transferred to C3H germfree mice. The barrier effect was maintained in the axenic mice. The comparative bacteriological analysis of hamster and mouse feces did not reveal important variations in the dominant anaerobic flora (P less than 0.01). After treatment with erythromycin, the barrier effect was maintained and while the disappearance of Escherichia coli was observed, the dominant anaerobic flora persisted. After dilution (10(-2] and subsequent heating (70 degrees C, 10 min) of caecal contents, the inhibitory activity against C. difficile was maintained although the number of aerobic and aerotolerant bacteria was reduced. The isolation from caecal microflora of anaerobic strains implicated in the resistance to colonization is presently underway in Freter anaerobic chambers.     

Effects of antibacterial agents on in vitro ovine ruminal biotransformation of the hepatotoxic pyrrolizidine alkaloid jacobine.

Ingestion of pyrrolizidine alkaloids, naturally occurring plant toxins, causes illness and death in a number of animal species. Senecio jacobaea pyrrolizidine alkaloids cause significant economic losses due to livestock poisoning, particularly in the Pacific Northwest. Some sheep are resistant to pyrrolizidine alkaloid poisoning, because ovine ruminal biotransformation detoxifies free pyrrolizidine alkaloids in digesta. Antibacterial agents modify ruminal fermentation. Pretreatment with antibacterial agents may account for some animal variability in resistance to pyrrolizidine alkaloid toxicosis, and antibacterial agents can also be used for characterizing ruminal pyrrolizidine alkaloid-biotransforming microflora. The objective of this study was to evaluate the effects of antibacterial agents on biotransformation of a predominant S. jacobaea pyrrolizidine alkaloid, jacobine, in ovine ruminal contents. Ovine ruminal jacobine biotransformation was tested in vitro with 20 independent antibacterial agents. Low amounts of rifampin and erythromycin prevented jacobine biotransformation. Chlortetracycline, lasalocid, monensin, penicillin G, and tetracycline were slightly less effective at inhibiting jacobine biotransformation. Bacitracin, crystal violet, kanamycin, and neomycin were moderately inhibitory against jacobine biotransformation. Brilliant green, chloramphenicol, gramicidin, nalidixic acid, polymyxin B SO4, sodium azide, streptomycin, sulfisoxazole, and vancomycin had little to no effect on jacobine biotransformation. The antibiotics that were most effective at inhibiting biotransformation were those that are active against gram-positive bacteria. Therefore, gram-positive bacteria are most likely critical members of the jacobine-biotransforming consortia.     

Effects of antibacterial agents on in vitro ovine ruminal biotransformation of the hepatotoxic pyrrolizidine alkaloid jacobine.

Ingestion of pyrrolizidine alkaloids, naturally occurring plant toxins, causes illness and death in a number of animal species. Senecio jacobaea pyrrolizidine alkaloids cause significant economic losses due to livestock poisoning, particularly in the Pacific Northwest. Some sheep are resistant to pyrrolizidine alkaloid poisoning, because ovine ruminal biotransformation detoxifies free pyrrolizidine alkaloids in digesta. Antibacterial agents modify ruminal fermentation. Pretreatment with antibacterial agents may account for some animal variability in resistance to pyrrolizidine alkaloid toxicosis, and antibacterial agents can also be used for characterizing ruminal pyrrolizidine alkaloid-biotransforming microflora. The objective of this study was to evaluate the effects of antibacterial agents on biotransformation of a predominant S. jacobaea pyrrolizidine alkaloid, jacobine, in ovine ruminal contents. Ovine ruminal jacobine biotransformation was tested in vitro with 20 independent antibacterial agents. Low amounts of rifampin and erythromycin prevented jacobine biotransformation. Chlortetracycline, lasalocid, monensin, penicillin G, and tetracycline were slightly less effective at inhibiting jacobine biotransformation. Bacitracin, crystal violet, kanamycin, and neomycin were moderately inhibitory against jacobine biotransformation. Brilliant green, chloramphenicol, gramicidin, nalidixic acid, polymyxin B SO4, sodium azide, streptomycin, sulfisoxazole, and vancomycin had little to no effect on jacobine biotransformation. The antibiotics that were most effective at inhibiting biotransformation were those that are active against gram-positive bacteria. Therefore, gram-positive bacteria are most likely critical members of the jacobine-biotransforming consortia.