Roncero C, Darzins A, Casadaban M J
Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637.
J Bacteriol. 1990 Apr;172(4):1899-904. doi: 10.1128/jb.172.4.1899-1904.1990.
Pseudomonas aeruginosa transposable bacteriophages D3112 and B3 were found to require pili for infection. Seventy mutants of P. aeruginosa PAO selected by resistance to D3112 or B3 were also resistant to the phage not used in the selection and suggested that the receptors of these two phages are identical. Of five resistant mutants examined, all were defective in the production of pili and did not adsorb either phage. P. aeruginosa PAK strains altered in pilus expression, such as hyperpiliated or nonpiliated mutants, adsorbed the phage but were not productively infected, implying that an additional host function was required for infection. The cell-associated lipopolysaccharide was not required for D3112 or B3 infection, since mutants deficient in O side-chain and core biosynthesis were still capable of adsorption and productive infection. This is in contrast to Escherichia coli mutator phages Mu and D108, which are dependent on lipopolysaccharide for adsorption. The P. aeruginosa phages adsorbed only to cells grown on solid media or in liquid media supplemented with agents that increase the macroviscosity, such as polyvinylpyrrolidone. Adsorption time course studies of D3112 and B3 using cells grown in solid media revealed similar but not identical adsorption patterns. These studies suggested that expression of the D3112 and B3 cell receptor is induced by growth on solid media.
发现铜绿假单胞菌转座噬菌体D3112和B3感染需要菌毛。通过对D3112或B3的抗性筛选出的70个铜绿假单胞菌PAO突变体，对未用于筛选的噬菌体也具有抗性，这表明这两种噬菌体的受体是相同的。在检测的5个抗性突变体中，所有突变体的菌毛产生均有缺陷，且均不吸附任何一种噬菌体。菌毛表达发生改变的铜绿假单胞菌PAK菌株，如菌毛增多或无菌毛突变体，能吸附噬菌体，但不能进行有效感染，这意味着感染还需要额外的宿主功能。D3112或B3感染不需要细胞相关脂多糖，因为缺乏O侧链和核心生物合成的突变体仍能吸附并进行有效感染。这与大肠杆菌诱变噬菌体Mu和D108不同，后者吸附依赖于脂多糖。铜绿假单胞菌噬菌体仅吸附在固体培养基上生长的细胞或添加了增加宏观粘度的试剂（如聚乙烯吡咯烷酮）的液体培养基中生长的细胞上。使用在固体培养基中生长的细胞对D3112和B3进行吸附时间进程研究，结果显示吸附模式相似但不完全相同。这些研究表明，D3112和B3细胞受体的表达是由在固体培养基上生长诱导的。
