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文章研究了上海华山医院临床分离的金黄色葡萄球菌菌株对大环内酯类抗生素的耐药性及耐药基因的分布情况。通过MIC法对临床标本分离的27株金黄色葡萄球菌对大环内酯类抗生素药敏性进行检测,并通过PCR扩增分析其中14株菌携带的大环内酯类抗生素耐药基因。结果表明27株金黄色葡萄球菌对4种大环内酯类抗生素:红霉素、螺旋霉素I、阿奇霉素和克拉霉素的耐药率分别为74.1%,48.1%,74.1%和74.1%;对林可酰胺类抗生素林可霉素的耐药率为77.8%;对酮内酯类抗生素泰立霉素的耐药率为77.8%。分析了其中14株临床菌的23rRNA序列保守碱基位点的突变和所携带的大环内酯类抗生素耐药基因情况。结果表明这14株临床菌的23rRNA序列保守碱基位点均没有发生突变。根据耐药基因PCR检测结果,发现这14种临床菌株中,有6株ermA阳性菌和和3株ermC阳性菌,但是并没有发现ermB的阳性菌株;ermA和ermC的检出率分别是42.86%和21.43%;耐药基因ermA存在于MRSA菌株中,其阳性率85.71%;而耐药基因ermC则出现在MSSA菌株中,其阳性率42.86%。另外,耐药基因msr A在14株临床分离菌株的检出率是92.86%,但没有发现它和大环内酯抗生素的药物敏感性存在相关性。27株临床分离菌株对除螺旋霉素I外的其它5种大环内酯-林可酰胺类抗生素耐药率均大于70%。耐药基因ermA和ermC是金黄色葡萄球耐药的主要原因。
In this paper, the clinical isolates of Staphylococcus aureus from Shanghai Huashan Hospital were investigated for their resistance to macrolide antibiotics and the distribution of drug resistance genes. 27 strains of Staphylococcus aureus isolated from clinical samples by MIC method were tested for susceptibility to macrolide antibiotics, and 14 strains of macrolide antibiotic resistance genes carried by PCR were amplified by PCR. The results showed that the resistance rates of 27 strains of Staphylococcus aureus to four macrolide antibiotics, erythromycin, spiramycin I, azithromycin and clarithromycin were 74.1%, 48.1%, 74.1% and 74.1%, respectively. The resistance rate to lincomycin lincomycin was 77.8%, and the resistance rate to ketolide antibiotic tyritomycin was 77.8%. The mutations of the 23rRNA conserved base sites and the macrolide antibiotic resistance genes of 14 clinical isolates were analyzed. The results showed that these 14 strains of clinical 23rRNA sequence of conserved base sites were not mutated. According to the PCR results of resistant gene, 6 strains of ermA positive bacteria and 3 strains of ermC positive bacteria were found among the 14 clinical isolates, but no positive strains of ermB were found. The detection rates of ermA and ermC were 42.86% And 21.43%, respectively. The resistance gene ermA was present in MRSA strains with a positive rate of 85.71%. The resistance gene ermC was found in MSSA strains with a positive rate of 42.86%. In addition, the detection rate of the resistant gene msr A in 92 clinical isolates was 92.86%, but no correlation was found between the drug resistance of the drug resistant gene msr A and the macrolide antibiotic susceptibility. The resistance rates of 27 isolates to all 5 macrolide-lincosamide antibiotics except spiramycin I were more than 70%. Resistance genes ermA and ermC are the main causes of resistance in S. aureus.