湿型外耳道分泌物的菌群结构及其药物敏感性分析

人的外耳道中存在种类繁多的微生物。为了解健康人湿型外耳道分泌物中的细菌数量、种类及其对药物敏感性，收集了38例无耳道疾病健康人左、右耳的湿型外耳道分泌物76份。采用分离培养的方法进行平板涂布、菌落计数及鉴定，分析其菌群数量及种类；通过纸片扩散法(Kirby-Bauer纸片扩散法)对分离的细菌进行药物敏感性试验，并利用头孢硝噻吩纸片检测青霉素耐药株产β-内酰胺酶情况。结果显示，88.3%的湿型外耳道分泌物的菌群数量在1×10² CFU/mL～1×10⁶ CFU/mL；共检出细菌20种，其中球菌占97.1%，主要为葡萄球菌；杆菌为2.9%。分离率前4位的细菌为头葡萄球菌、耳葡萄球菌、人葡萄球菌和表皮葡萄球菌，对临床常用的妥布霉素、米诺环素、万古霉素和呋喃妥因等抗生素敏感率达90.0%以上；对复方新诺明和青霉素耐药率相对较高，但低于50.0%。分离得到的132株葡萄球菌中，25株对青霉素耐药，耐药株的β-内酰胺酶阳性率为44.0%。结果提示，从健康人湿型外耳道分泌物中分离的细菌种类多样，以葡萄球菌为主，对临床常用的抗生素有较高的敏感性，但对青霉素、复方新诺明等具有一定耐药性。

Microflora and drug sensitivity of external auditory canal secretions collected from healthy people with wet ear

To understand the quantity, species, and drug sensitivity of bacteria in the external auditory canal of healthy people with wet ear, the secretions of both right and left ears were collected from 38 healthy wet ear people without ear diseases. A total of 76 samples were subjected to standard clinical culture and isolation procedure on LB plates. The total number of colonies were counted, and representative colonies were subjected to species identification (VETEK-2) and drug sensitivity assays (Kirby-Bauer test). The beta-lactamase of penicillin resistant strains was detected by method of cefnithiphene disk. The results showed that the bacterial number in 88.3% of samples were within 1×10² CFU/sample～1×10⁶ CFU/sample. 20 species of bacteria were detected, 97.1% were cocci and 2.9% were bacilli. The top four bacteria were Staphylococcus cephalus, Staphylococcus auriculae, Staphylococcus hominus and Staphylococcus epidermidis. The sensitivity rate to tobramycin, minocycline, vancomycin and furantoin were more than 90.0%, and resistant rate to cotrimoxazole and penicillin was 50%; 25 of 132 Staphylococcus strains were resistant to penicillin and the positive rate of beta-lactamase was 44.0%.