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1.
为了研究鱼腥草素钠对金黄色葡萄球菌(S.aureus)生物被膜的抑制活性,试验采用微量稀释法考察了鱼腥草素钠对S.aureus浮游菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC),用琼脂平板法测定了其对生物被膜的最小抑膜浓度(MBIC)和最小杀膜浓度(MBBC);通过激光共聚焦显微镜考察了鱼腥草素钠对生物被膜的清除能力;通过Western-blot考察了鱼腥草素钠对S.aureus毒力因子分泌的影响。结果表明:鱼腥草素钠对浮游菌有很好的抑制作用(MIC、MBC:16~64μg/mL),对成熟的生物被膜没有明显的抑制作用(MBIC、MBBC1 024μg/mL),但其亚抑菌浓度在生物被膜形成早期有显著抑制作用,并呈剂量依赖抑制α-溶血素、肠毒素A和肠毒素B的分泌。说明鱼腥草素钠对金黄色葡萄球菌浮游菌和早期生物被膜有较好抑制活性。  相似文献   

2.
赤芍水提物对金黄色葡萄球菌肠毒素及蛋白A表达的影响   总被引：1，自引：0，他引：1  
探讨了赤芍水提物在体外对金黄色葡萄球菌肠毒素A、B及蛋白A分泌及mRNA转录的影响。试验中采用微量倍比稀释法测定赤芍对金黄色葡萄球菌ATCC29213的最小抑菌浓度(MIC);采用Western blot和实时荧光定量PCR检测亚抑菌浓度下赤芍水提物对金黄色葡萄球菌肠毒素A、B及蛋白A在mRNA转录和毒素蛋白分泌表达的影响。结果表明,赤芍水提物对金黄色葡萄球菌ATCC29213的MIC值为6.3mg/mL;在亚抑菌浓度下,赤芍水提物可以明显抑制肠毒素A、B及蛋白A在蛋白水平和转录水平的表达,且呈现明显的浓度依赖性。  相似文献   

3.
为了研究黄连生物碱的抑菌活性,采用高速逆流色谱(HSCCC)法分离黄连生物碱,K-B法检测其抑菌活性,测其对敏感菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。结果显示：从黄连中分离出黄连碱、掌叶防己碱、小檗碱、表小檗碱,提取率分别为44.41%、36.72%、68.54%、18.33%;对金黄色葡萄球菌的抑菌圈分别为10.00、29.50、21.00和12.50 mm;对无乳链球菌分别为11.40、27.50、14.00和15.50 mm;对粪肠球菌、大肠杆菌O157等均无效;黄连碱、表小檗碱对金黄色葡萄球菌、无乳链球菌的MIC和MBC均分别为136.36、272.73μg/mL;小檗碱对金黄色葡萄球菌的MIC和MBC分别为62.18、136.36μg/mL,对无乳链球菌的MIC和MBC分别为136.36、272.73μg/mL;掌叶防己碱对金黄色葡萄球菌、无乳链球菌的MIC和MBC均分别为62.18、136.36μg/mL。结果表明：用HSCCC制备生物碱,省时、方便,4种生物碱对金黄色葡萄球菌和无乳链球菌作用明显,对其余试验菌无效。  相似文献   

4.
通过微量稀释法、结晶紫染色法、生物被膜内活菌计数及生物被膜的形态学观察,探讨黄连水提物、盐酸小檗碱及黄连碱对猪链球菌生物被膜的体外干预作用。结果显示,黄连水提物、盐酸小檗碱、黄连碱对猪链球菌的最小抑菌浓度(MIC)分别为:100μg/mL、62.5μg/mL、62.5μg/mL。亚抑菌浓度的黄连水提物、盐酸小檗碱和黄连碱均可抑制生物被膜的形成,盐酸小檗碱作用后生物被膜内活菌数较阴性对照组明显减少(P0.05),电镜观察可见与阴性对照组相比,黄连水提物、盐酸小檗碱和黄连碱试验组生物被膜结构被破坏,菌量明显减少。研究表明,50μg/mL黄连水提物、31.25μg/mL盐酸小檗碱和31.25μg/mL黄连碱对猪链球菌体外生物被膜的形成具有显著的干预作用。  相似文献   

5.
对大肠杆菌和金黄色葡萄球菌进行正己酸的抗性试验,以研究正己酸对病原菌的抑制作用。试验采用等浓度梯度稀释、光密度值测定、平板涂布方法、牛津杯法,分别测定大肠杆菌及金黄色葡萄球菌的的最小抑菌浓度(minimum inhibitory concentration,MIC)以及最小杀菌浓度(minimum bactericidal concentration,MBC),绘制1/2MIC以及MIC处理过的大肠杆菌以及金黄色葡萄球菌的生长曲线,抑菌圈直径,结合扫描电镜图片分析最小杀菌浓度处理后的细胞形态结构的变化。结果表明:正己酸对大肠杆菌的最小抑菌浓度为700μg/mL、对金黄色葡萄球菌的最小抑菌浓度为1 000μg/mL;对大肠杆菌的最小杀菌浓度为1 000μg/mL、对金黄色葡萄球菌的最小杀菌浓度为1 300μg/mL;当正己酸浓度为1 600μg/mL时,电镜下,大肠杆菌数量较少,金黄色葡萄球菌数量少且呈现出细胞破裂萎缩现象。综上,正己酸对大肠杆菌和金黄葡萄球菌有抑制作用,破坏了金黄葡萄球菌的细胞膜结构。  相似文献   

6.
穿心莲内酯影响猪链球菌生物被膜形成   总被引：1，自引：0，他引：1  
旨在探究穿心莲内酯对猪链球菌生物被膜形成的抑制作用,为猪链球菌病的耐药性提供替代疗法。试验采用微量稀释法测定穿心莲内酯对猪链球菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC);利用结晶紫染色(CV)和扫描电镜(SEM)检测穿心莲内酯对猪链球菌生物被膜形成的影响。结果表明:1)穿心莲内酯对猪链球菌的MIC和MBC分别为0.25和0.5mg·mL~(-1);2)扫描电镜观察可见阴性对照组细菌镶嵌于生物被膜中,而穿心莲内酯在亚抑菌浓度下(1/2MIC、1/4MIC、1/8MIC)能使细菌生物被膜中的细菌数量和生物被膜形成量均减少,并呈剂量依赖性;3)luxS基因和毒力基因的RT-PCR检测显示亚抑菌浓度(1/2MIC、1/4MIC)的穿心莲内酯明显降低gapdh、sly、fbps、ef和luxS基因的转录,显著增加cps2J、mrp和gdh基因的转录;4)哈维氏弧菌生物发光法测定细菌培养液显示穿心莲内酯在亚抑菌浓度下(1/2MIC、1/4MIC、1/8MIC)对猪链球菌AI-2信号分子的产生有抑制作用,呈剂量依赖性。穿心莲内酯亚抑菌浓度的干预可抑制猪链球菌生物被膜的形成,并且可致毒力基因表达水平差异。  相似文献   

7.
为探究苦参碱对产膜表皮葡萄球菌(Staphylococcus epidermidis,SE)Ⅰ类整合酶基因(class 1integrase gene,intI1)的影响,本试验采用二倍稀释法分别测定苦参碱、苦豆子碱、卡那霉素和头孢西汀对SE的最低抑菌浓度(MIC);利用棋盘滴定法测定4种药物对SE的联合作用的效果;用XTT法测定不同质量浓度下药物对产膜阳性菌株的抑菌效果并绘制其抑制曲线;采用荧光定量PCR方法分析药物对生物膜状态下intI1在mRNA水平表达的影响。结果显示:苦参碱、苦豆子碱、卡那霉素和头孢西汀对产膜阳性菌株的MIC分别是12.5g/L、20g/L、512mg/L、128mg/L;它们在亚抑菌浓度下均对产膜阳性菌株有一定的抑菌作用;取1/2MIC的药物质量浓度对产膜阳性菌株作用2h和4h,发现苦参碱作用4h后intI1基因表达量下调,表明苦参碱对在生物被膜状态下的SE中intI1在mRNA水平上有抑制作用,提示苦参碱对被膜状态下的SE的整合酶基因表达量有一定的抑制作用,从而影响整合子在生物被膜状态下捕获耐药基因的能力。  相似文献   

8.
为了探究利福昔明、精油单独和联合应用对乳房炎源金黄色葡萄球菌(金葡菌)及其生物被膜形成的抑制作用,测定利福昔明、精油对9株金葡菌临床分离株的最低抑菌浓度(MIC)和最低抑膜浓度(MBIC),棋盘法测定二者对金葡菌菌株S.a-2的联合抑菌指数(FICI),研究其对金葡菌菌株S.a-2生物被膜形成的作用。结果显示:利福昔明对金葡菌的MIC为0.016～4.00μg·mL~(-1),3种精油中,薄荷油的抑菌作用最强,MIC为0.16%～2.50%,且与利福昔明联合表现相加作用;利福昔明联合1/2 MIC、1/8 MIC薄荷油对金葡菌菌株S.a-2生物被膜形成的抑制率为90%和51%,极显著高于1/2 MIC、1/8 MIC薄荷油单独组(61%和37%)及利福昔明组(40%)(P0.01);利福昔明联合1/4 MIC薄荷油的抑制率为62%,极显著高于利福昔明组(P0.01),显著高于1/4 MIC薄荷油组(53%)(P0.05);利福昔明联合1/16 MIC的薄荷油的抑制率为44%,与1/16 MIC薄荷油组(41%)及利福昔明组差异不显著(P0.05)。结果表明:利福昔明、薄荷油单独作用对金葡菌菌株S.a-2生物被膜的形成有明显抑制,一定浓度的薄荷油与利福昔明联合应用对其有更强抑制作用。  相似文献   

9.
为了研究不同浓度的大蒜素溶液对金黄色葡萄球菌的抑制作用,试验采用XTT法检测了不同浓度大蒜素(512,256,128,64,32,16,8,4,2,1μg/m L)处理对不同生长时间的金黄色葡萄球菌N2分离株生物被膜的影响。结果表明:大蒜素浓度与OD450值呈反比。512μg/m L浓度大蒜素作用于金黄色葡萄球菌N2菌株后测得的OD450值均0. 1,表现为对生物被膜的强烈抑制作用;256,128,64,32,16,8,4μg/m L浓度大蒜素作用于金黄色葡萄球菌N2菌株后测得的OD450值均≥0. 1～≤0. 4,表现为对生物被膜的明显抑制作用;2,1μg/m L浓度的大蒜素作用于金黄色葡萄球菌N2菌株后测得的OD450值均0. 4,表现为对生物被膜的微弱抑制作用。说明大蒜素浓度是影响金黄色葡萄球菌N2分离菌生物被膜的主要因素,大蒜素浓度为512μg/m L时呈现明显的杀菌作用。  相似文献   

10.
文章旨在研究体外条件下辣椒碱对鸭源性大肠杆菌、沙门氏菌和金黄色葡萄球菌抑菌效果和抗氧化能力。试验采用平板涂布法测定辣椒碱对3种致病菌的MIC,采用比浊法测定不同时间点菌液的光密度(OD值),绘制生长曲线。采用体外法测定辣椒碱对1,1-二苯基-二苦基肼(DPPH)、超氧阴离子和羟自由基的清除率评价辣椒碱的抗氧化能力。结果显示,辣椒碱对大肠杆菌、沙门氏菌和金黄色葡萄球菌的最小抑菌浓度(MIC)分别1、2、2 g/L,对DPPH、超氧阴离子和羟自由基均有一定的清除能力。试验表明,辣椒碱对大肠杆菌、沙门氏菌和金黄色葡萄球菌的抑菌效果明显,是一种良好的抑菌剂和抗氧化剂。  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
Tropical Animal Health and Production -  相似文献   

14.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

15.
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.  相似文献   

16.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

17.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

18.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

19.
The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.  相似文献   

20.
<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.  相似文献   

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