乳源金黄色葡萄球菌耐药性及耐β-内酰胺类药基因的研究

发布时间：2018-01-21 13:06

本文关键词： 金黄色葡萄球菌耐药菌株生鲜牛乳 β-内酰胺耐药基因　出处：《内蒙古农业大学》2012年硕士论文　论文类型：学位论文

【摘要】：试验从呼和浩特及周边地区农牧场采集生鲜牛乳样品52份,根据微生物学和分子生物学方法,对样品中金黄色葡萄球菌进行分离鉴定,药敏性试验,并对筛选的耐药菌株β-内酰胺类耐药基因mecA和femA进行PCR扩增检测。研究结果表明：52份样品中分离鉴定出28株金黄色葡萄球菌,用杯碟法对分离菌株进行耐药性初筛,参照CLSI规定的标准进行耐药性判定,结果显示28个分离株对8种抗生素均有不同程度的耐药性,其中对红霉素和氨苄西林的耐药率最高,达到96.4%,其次是青霉素的耐药率在89.3%,氧氟沙星为85.7%,链霉素的耐药率也较高,达到71.4%,头孢噻肟和诺氟沙星耐药率较低,分别是35.7%和39.3%,耐药率最低的是头孢唑啉为10.7%。从初筛所得耐药菌株中选出6株相对耐氧氟沙星、红霉素、青霉素和头孢唑啉的菌株,分别是SA2、 SA5、 SA8、 SA13、 SA20和SA24。采用试管二倍稀释法和杯碟法对这6株试验菌株进一步进行药敏性试验,6株菌对9种抗生素同时具有不同程度的耐药性。其中,菌株SA13对头孢噻肟、诺氟沙星和链霉素相对敏感外,其他均有耐药性；菌株SA8和SA13对氧氟沙星相对敏感外,其他都有耐药性；菌株SA24对头孢唑啉相对敏感,而其他都有耐药性：所有试验菌株对青霉素V和氨苄西林都有很高的耐药性。用PCR方法检测6株试验菌株的1mecA基因,结果只有1株菌(SA24) mecA基因为阳性,同源性为99%,其他都为阴性。测得femA基因全部阳性,并且同源性为100%。
[Abstract]:52 samples of fresh milk were collected from Huhhot and its surrounding farms. According to microbiological and molecular biological methods, Staphylococcus aureus in the samples were isolated and identified. The 尾-lactam resistant genes mecA and femA were amplified by PCR. The results showed that 28 strains of Staphylococcus aureus were isolated and identified from 52 samples. The drug resistance of the isolated strains was screened with the method of cup plate, and the drug resistance was determined according to the standard set by CLSI. The results showed that 28 strains were resistant to 8 kinds of antibiotics to varying degrees, and the resistance rate to erythromycin and ampicillin was the highest (96.4%), followed by penicillin resistance rate (89.3%). Ofloxacin was 85.7 and streptomycin resistance was 71.4. Cefotaxime and norfloxacin were 35.7% and 39.3% respectively. The resistance rate of cefazolin was 10.7.The six strains which were resistant to ofloxacin, erythromycin, penicillin and cefazolin were selected from the resistant strains, which were SA2 and SA5, respectively. SA8, SA13, SA20 and SA24. the drug sensitivity of the 6 strains was further tested by double dilution method and cup dish method. The 6 strains were resistant to 9 antibiotics at the same time. Among them, the strain SA13 was relatively sensitive to cefotaxime, norfloxacin and streptomycin, but the others were resistant. The strains SA8 and SA13 were relatively sensitive to ofloxacin and the other strains were resistant to ofloxacin. The strain SA24 was relatively sensitive to cefazolin, while the others were resistant: all the tested strains were highly resistant to penicillin V and ampicillin. 1 mecA gene of 6 tested strains was detected by PCR method. Only 1 strain SA24) mecA gene was positive, and the homology was 99%. All the others were negative. All the femA genes were positive, and the homology was 100%.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R378

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