DNase test and PCR were both opsitive in 48 of 68 c1inica isolates and the other 20strains were all negative, the results of PCR were all the same as DNase test in detecting M.catarrhalis.

• 20株DNA酶试验阴性菌株PCR结果亦阴性,PCR检测和 DNA酶检测符合率达100%25(68/68)。