DGGE法分析慢性化脓性中耳炎耳道菌群变化及药敏试验研究

目的解析正常成人及慢性化脓性中耳炎（CSOM）患者耳道内菌群结构的差别，寻找有效抑制致病菌同时对皮肤主导菌群影响不大的抗生素，指导临床合理用药。方法取20例正常成人及20例CSOM患者耳道分泌物行血琼脂平板划线法分离鉴定细菌，选择典型病例进行DGGE法分析耳道菌群多样性，对培养的常见细菌进行药物敏感试验，分析药敏结果。结果（1）20例正常成人耳道分泌物中18例培养分离出表皮葡萄球菌（90％），2例培养阴性（10％）；20例CSOM患者耳道分泌物中离出金黄色葡萄球菌8例（40％），铜绿假单胞菌5例（25％），溶血性葡萄球菌、表皮葡萄球菌各2例（各10％），阴沟肠杆菌、洋葱伯克霍尔德菌各1例（各5％），无菌生长1例（5％）。（2）DGGE分析显示，正常成人耳道菌群种类比CSOM明显增多。（3）金黄色葡萄球菌、表皮葡萄球菌、铜绿假单胞菌对环丙沙星均敏感。表皮葡萄球菌对阿莫西林、头孢唑林、左旋氧氟沙星耐药而金黄色葡萄球菌对其敏感。结论（1）正常人耳道正常菌群多样性高于CSOM。（2）目前培养出的正常成人主要耳道菌群为表皮葡萄球菌，CSOM主要菌群为金黄色葡萄球菌、铜绿假单胞菌。（3）环丙沙星同时抑制正常菌群和致病菌的生长。阿莫西林、头孢唑林、左旋氧氟沙星在抑制金黄色葡萄球菌等致病菌的同时，可以在一定程度上保护正常菌群成员表皮葡萄球菌。

DGGE analysis of chronic suppurative otitis media ear canal flora changes and drug susceptibility

Objective To analyze the difference in ear canal flora structure between normal adults and CSOM （chronic suppurative otitis media） patients, looking for the antibiotics thai have effective inhibition on pathogenic bacteria while little impact on the normal microbiota, and guide the clinical rational drug use. Methods Blood AGAR plate was used for separation and identification of the pathogens, DGGE for the analysis of ear canal flora diversity. Drug sensitivity experiment was performed. Results （ 1 ） Epidermis staphylococcus was isolated in 18 cases of the 20 cases normal adult ear secretions （90%）. From the ear secretions of 20 patients with CSOM, Staphylococcus aureus was isolated in 8 eases （40%） , Pseudomonus aeruginosa in 5 eases （25%） , Staphylococcus epidermis in 2 cases （10%） , Hemolytic staphylococci in 2 cases （10%） , intestinal bacteria in 1 case （5%） , onion Burkholderia bacteria in 1 case （5%）, and germfree in 1 case （5%）. （2） DGGE analysis showed that the flora species in normal adult ear canal were more abundant than in CSOM. （3） Staphylococcus aureus and Epidermis staphylococcus were sensitive to ciprofloxacin. Staphylococcus aureus was sensitive while Epidermis staphylococcus was resistant to amoxicillin, cefazolin, and ofloxacin. Conclusion （ 1 ） Microbiota diversity in normal adult ear is higher than in CSOM patients. （2） With the existing culture method, Epidermis staphylococcus is the dominant bacteria in noruml ear canal while Staphylococcus aureus, Pseudomonas aeruginosa and Pseudomonas aeruginosa are the dominant microflora in CSOM ear canal. （3） Ciprofloxacin inhibits both normal flora and pathogenic bacteria. Amoxicillin, cefazolin and ofloxacin, which inhibit pathogenic bacteria such as Staphylococcus aureus, can protect normal flora Staphylococcus epidermidis to some extent.