Hsiao C B, Sethi S, Murphy T F
Division of Infectious Diseases, State University of New York at Buffalo, USA.
Microb Pathog. 1995 Oct;19(4):215-25. doi: 10.1016/s0882-4010(95)90272-4.
Branhamella catarrhalis causes lower respiratory tract infections in patients with chronic obstructive pulmonary disease. The outer membrane protein CD (OMP-CD) of B. catarrhalis is a major, heat-modifiable OMP. The goals of this study are to characterize the degree of conservation of OMP-CD among strains and to investigate if OMP-CD maintains its homogeneity under the effect of host immune selective pressure. Isolates of B. catarrhalis were collected prospectively from patients with bronchiectasis and chronic bronchitis. We studied the OMP-CD gene by analysis of PCR restriction fragment length polymorphisms (PCR-RFLP) and further determined DNA sequence of the CD gene of eight selected isolates. Five patterns of PCR-RFLP of the OMP-CD gene were observed among all isolates when the gene was digested with Sau3AI. The sequence analysis revealed a high degree of homogeneity in OMP-CD among strains of B. catarrhalis. Three regions of OMP-CD with minimal sequence heterogeneity were identified. The sequences of the OMP-CD gene of isolates collected from patients colonized with the same strain for up to 6 months was identical. These observations establish that the OMP-CD of B. catarrhalis recovered from clinical isolates is highly conserved among strains.
卡他布兰汉菌可导致慢性阻塞性肺疾病患者发生下呼吸道感染。卡他布兰汉菌的外膜蛋白CD（OMP-CD）是一种主要的、可热修饰的外膜蛋白。本研究的目的是确定菌株间OMP-CD的保守程度，并研究OMP-CD在宿主免疫选择压力作用下是否保持其同质性。前瞻性地收集支气管扩张症和慢性支气管炎患者的卡他布兰汉菌分离株。我们通过分析PCR限制性片段长度多态性（PCR-RFLP）研究OMP-CD基因，并进一步测定了8株选定分离株的CD基因的DNA序列。用Sau3AI消化该基因时，在所有分离株中观察到OMP-CD基因的5种PCR-RFLP模式。序列分析显示卡他布兰汉菌菌株间OMP-CD具有高度同质性。确定了OMP-CD的三个序列异质性最小的区域。从同一菌株定植长达6个月的患者中收集的分离株的OMP-CD基因序列相同。这些观察结果表明，从临床分离株中回收的卡他布兰汉菌的OMP-CD在菌株间高度保守。
