人咽拭子中肺炎嗜衣原体基因型的初步鉴定

Identification of OmpA Genetype of Chlamydophila Pneumoniae in Human Nasopharyngeal Swabs

目的了解中国咽部感染患者肺炎嗜衣原体(Cpn)的基因型。方法从中国不同城市收集疑为Cpn感染患者的咽拭子标本465份,巢式PCR扩增Cpn主要外膜蛋白基因(ompA)片段,其中包括4个变异区,对所得58份阳性标本进行ompA基因序列测序,对照Cpn参考株基因,根据同源性对这些临床株基因进行分型。结果从58份Cpn临床株标本中,检出CpnA、CpnB、CpnC、CpnD共4种基因型,14个基因变体,其中以C型最为常见(89.7%),其次依次为A型(5.2%)、B型(3.4%)、D型(1.7%)。结论在中国部分城市,Cpn存在CpnA、CpnB、CpnC、CpnD等4个基因型,其中以C型最为常见,呈现较大的多态性,可为其疫苗的研制提供重要的实验依据。

Objective To know ompA genetype of Chlamydia pneumoniae in human nasopharyngeal swabs. Method 465 human nasopharyngeal swabs were collected from different cities in China doubted Chlamydia pneumoniae （Cpn） infection. DNA was extracted by usual method, and an approximately 366 bp fragment from the major outer membrane protein（ompA） gene of Cpn was amplified by nested polymerase chain reaction（nPCR）. The PCR products were purified by DNA agarose gel purification system and the sequence of the ompA gene was determined by sequencing analyzer. And genotype was performed by BLAST similarity search compared with Cpn reference strains. Results 58 clinical strains were identified from human nasopharyngeal swabs. The overall 14 genetic variants were detected and 4 genetype exactly A, B, C, D were confirmed. The most prevalent genotype was CpnC （89.7%） , and the rest of all are CpnA （5.2%） , CpnB （3.4%） and CpnD（ 1.7% ）. Conclusion There are a few genetype of Cpn in a few cities in China. CpnC was found mostly,and the others were appeared such as CpnA, CpnB and CpnD. It exhibits remarkable ompA DNA sequence polymorphism, which can encourage us for vaccine design and infection control.