期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
黄瓜白粉病菌对己唑醇的敏感基线及实验室抗性获得 被引量:13
1
作者 杨连来 刘玮玮 +2 位作者 刘跃群 慕卫 刘峰 《植物保护学报》 CAS CSCD 北大核心 2007年第4期431-435,共5页
为了评价黄瓜白粉病菌对己唑醇的抗性风险,采用子叶法测定了山东地区50个黄瓜白粉病菌菌株对己唑醇的敏感性。结果表明,各菌株敏感性存在较大差异,EC50值最低为0.0017μg/mL,最高达0.16μg/mL,平均值为0.028μg/mL,由于所有菌株均采自... 为了评价黄瓜白粉病菌对己唑醇的抗性风险,采用子叶法测定了山东地区50个黄瓜白粉病菌菌株对己唑醇的敏感性。结果表明,各菌株敏感性存在较大差异,EC50值最低为0.0017μg/mL,最高达0.16μg/mL,平均值为0.028μg/mL,由于所有菌株均采自未使用过脱甲基抑制剂类杀菌剂的黄瓜日光温室,敏感性频率呈近似正态分布,可作为黄瓜白粉病菌对己唑醇的相对敏感基线。以野生菌株为材料,以紫外线诱导和药剂驯化相结合获得了2个黄瓜白粉病菌对己唑醇的抗性菌株,比较了抗性菌株和敏感菌株的适合度和分生孢子的竞争能力。结果表明,无药情况下2个抗性菌株与野生菌株适合度无显著差异。抗性菌株和敏感菌株分生孢子以80∶20混合培养7代后,抗性菌株的频率变化不明显;50∶50混合培养7代,中抗菌株的抗性频率明显降低,而高抗菌株的抗性频率降低不明显;20∶80混合培养7代,抗性菌株的频率变低甚至消失。 展开更多
关键词 黄瓜白粉病菌 己唑醇 敏感基线 实验室抗性 适合度
原文传递
白纹伊蚊实验室抗溴氰菊酯品系筛选及其形态变化和钠通道基因分析 被引量:2
2
作者 蔡微 徐昕 +1 位作者 杨永红 郑学礼 《热带医学杂志》 CAS 2020年第2期180-184,199,F0003,共7页
目的揭示实验室内白纹伊蚊溴氰菊酯抗性汰选中蚊抗性发展趋势、形态表型和蚊击倒抗性相关钠离子通道(VGSC)结构域Ⅲ基因片段(Kdr)的变化。方法实验室严格控制饲养条件,用溴氰菊酯汰选白纹伊蚊至30代,计算幼虫半数致死浓度(LC50)并获得... 目的揭示实验室内白纹伊蚊溴氰菊酯抗性汰选中蚊抗性发展趋势、形态表型和蚊击倒抗性相关钠离子通道(VGSC)结构域Ⅲ基因片段(Kdr)的变化。方法实验室严格控制饲养条件,用溴氰菊酯汰选白纹伊蚊至30代,计算幼虫半数致死浓度(LC50)并获得抗性倍数(RR),成蚊接触筒法计算成蚊死亡率。随机选取汰选白纹伊蚊抗性株及敏感株的雌蚊,测量成蚊的体长等8个形态学指标,并对所测形态指标数据进行统计分析。PCR扩增抗性株及敏感株雌蚊钠通道结构域Ⅲ基因片段,TA克隆,测序,进行序列分析。结果经过汰选,抗性株的LC50由0.020 mg/L变成0.048 mg/L,其抗性倍数为2.4倍。幼虫生物测量结果显示抗性株具有低度抗性,成蚊抗药性生物测试表明R-20代白纹伊蚊为抗性群体,且抗性级别为R。18代白纹伊蚊抗溴氰菊酯株(R)与敏感株(S)的体长、前腿长、中腿长、后腿长、翅长、翅宽、触角长和喙长均数差异有统计学意义(P<0.05)。随着代数的增加,白纹伊蚊抗性株在形态学各方面指标的均数呈现降低的趋势。测序显示,Kdr第96、132、204个位点碱基敏感株为C,而抗性株则突变为T;第111位敏感株碱基为A,抗性株则为G;第534位抗性株碱基由T突变为C。然而,敏感株及抗性株均未发现上述位点的氨基酸序列突变,未影响其蛋白质的表达。结论实验室内采用溴氰菊酯抗性汰选抗性白纹伊蚊模型成功。溴氰菊酯汰选抗性白纹伊蚊形态表型发生变化,溴氰菊酯汰选抗性白纹伊蚊的19代、20代蚊Kdr基因一些位点发生碱基突变,但对应的氨基酸序列没有改变。 展开更多
关键词 白纹伊蚊 溴氰菊酯 实验室抗性筛选 Kdr基因
原文传递
Microbial profile and antibiotic sensitivity pattern in bile cultures from endoscopic retrograde cholangiography patients 被引量:13
3
作者 Muhsin Kaya Remzi Bestas +3 位作者 Fatma Bacalan Ferhat Bacaksz Esma Gülsun Arslan Mehmet Ali Kaplan 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第27期3585-3589,共5页
AIM: To identify the frequency of bacterial growth, the most commonly grown bacteria and their antibiotic susceptibility, and risk factors for bacterial colonization in bile collected from patients with different bil... AIM: To identify the frequency of bacterial growth, the most commonly grown bacteria and their antibiotic susceptibility, and risk factors for bacterial colonization in bile collected from patients with different biliary dis- eases. METHODS: This prospective study was conducted be- tween April 2010 and August 2011. Patients with vari- ous biliary disorders were included. Bile was aspirated by placing a single-use, 5F, standard sphincterotome catheter into the bile duct before the injection of con- trast agent during endoscopic retrograde cholangio- pancreaticography (ERCP). Bile specimens were trans- ported to the microbiology laboratory in blood culture bottles within an anaerobic transport system. Bacteria were cultured and identified according to the standard protocol used in our clinical microbiology laboratory. The susceptibilities of the organisms recovered were identified using antimicrobial disks, chosen according tothe initial gram stain of the positive cultures RESULTS: Ninety-one patients (27% male, mean age 53.7 4- 17.5 years, range: 17-86 years) were included in the study. The main indication for ERCP was benign biliary disease in 79 patients and malignant disease in 12 patients. The bile culture was positive for bacterial growth in 46 out of 91 (50.5%) patients. The most frequently encountered organisms were Gram-negative bacteria including Escherich/a coli (28.2%), Pseudo- monas (17.3%) and Stenotrophomonas rnaltophilia (15.2%). There were no significant differences between patients with malignant and benign disease (58% vs 49%, P = 0.474), patients with acute cholangitis and without acute cholangitis (52.9% vs 50%, P = 0.827), patients who were empirically administered antibiotics before intervention and not administered (51.4% vs 60.7%, P = 0.384), with regard to the bacteriobilia. We observed a large covering spectrum or low resistance to meropenem, amikacin and imipenem. CONCLUSION: We did not find a significant risk fac- tor for bacteriobilia in patients with biliary obstruction. A bile sample for microbiological analysis may become a valuable diagnostic tool as it leads to more accurate selection of antibiotics for the treatment of cholangitis. 展开更多
关键词 CHOLANGITIS Endoscopic retrograde cholan-giopancreaticography Bacteriobilia Bile culture
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部