Tønjum T, Weir S, Bøvre K, Progulske-Fox A, Marrs C F
Kaptein W. Wilhelmsen og Frues Bakteriologiske Institutt, Rikshospitalet, Oslo, Norway.
Infect Immun. 1993 May;61(5):1909-16. doi: 10.1128/iai.61.5.1909-1916.1993.
Eikenella corrodens normally inhabits the human respiratory and gastrointestinal tracts but is frequently the cause of abscesses at various sites. Using the N-terminal portion of the Moraxella nonliquefaciens pilin gene as a hybridization probe, we cloned two tandemly located pilin genes of E. corrodens 31745, ecpC and ecpD, and expressed the two pilin genes separately in Escherichia coli. A comparison of the predicted amino acid sequences of E. corrodens 31745 EcpC and EcpD revealed considerable divergence between the sequences of these two pilins and even less similarity to EcpA and EcpB of E. corrodens type strain ATCC 23834. EcpC from E. corrodens 31745 displayed high degrees of homology to the pilins of Neisseria gonorrhoeae and Pseudomonas aeruginosa. EcpD from E. corrodens 31745 showed the highest homologies with the pilin of one of the three P. aeruginosa classes, whereas EcpA and EcpB of strain ATCC 23834 most closely resemble Moraxella bovis pilins. These findings raise interesting questions about potential genetic transfer between different bacterial species, as opposed to convergent evolution.
啮蚀艾肯菌通常栖息于人类呼吸道和胃肠道，但常引发身体各部位的脓肿。我们以不动杆菌属菌菌毛蛋白基因的N端部分作为杂交探针，克隆了啮蚀艾肯菌31745的两个串联排列的菌毛蛋白基因ecpC和ecpD，并分别在大肠杆菌中表达这两个菌毛蛋白基因。对啮蚀艾肯菌31745 EcpC和EcpD的预测氨基酸序列进行比较后发现，这两种菌毛蛋白的序列存在显著差异，与啮蚀艾肯菌模式菌株ATCC 23834的EcpA和EcpB的相似性更低。啮蚀艾肯菌31745的EcpC与淋病奈瑟菌和铜绿假单胞菌的菌毛蛋白具有高度同源性。啮蚀艾肯菌31745的EcpD与铜绿假单胞菌三类菌毛蛋白之一的菌毛蛋白具有最高同源性，而ATCC 23834菌株的EcpA和EcpB与牛莫拉菌的菌毛蛋白最为相似。这些发现引发了关于不同细菌物种之间潜在基因转移的有趣问题，而非趋同进化。
