Stevens P, Young L S, Adamu S
Immunology. 1983 Nov;50(3):497-502.
A virulence factor of E. coli K-1 is its capacity to avoid opsonization via the alternative complement pathway (ACP). Since it is not known if E. coli with other capsular (K) antigens have similar properties we examined various capsular E. coli for opsonization by the ACP. To assess opsonization we used whole blood luminol-dependent chemiluminescence (CL) and the magnesium salt of ethyleneglycol tetraacetic acid to block the classical pathway. E. coli K-types 6, 7, 27, 30, 42, 53, 57 and 75 were effectively opsonized via the ACP (greater than 65% of CL obtained with unchelated normal serum). K types 2 and 13 were opsonized by the ACP in both the high range greater than 65% and intermediate range 36-65%. Only K-types 1, 3, 5, 12 and 92 were poorly opsonized (less than 35%) by the ACP. The data demonstrate that most E. coli K-types were opsonized via the ACP. The poor opsonization of E. coli K3, 5, 12 and 92 by the ACP may be virulence factor for these bacteria.
大肠杆菌K-1的一个毒力因子是其通过替代补体途径（ACP）避免被调理吞噬的能力。由于尚不清楚带有其他荚膜（K）抗原的大肠杆菌是否具有类似特性，我们检测了各种荚膜型大肠杆菌通过ACP进行调理吞噬的情况。为评估调理吞噬作用，我们使用全血鲁米诺依赖性化学发光（CL）法，并使用乙二醇四乙酸镁盐来阻断经典途径。大肠杆菌K-6、K-7、K-27、K-30、K-42、K-53、K-57和K-75型可通过ACP有效被调理吞噬（大于用未螯合正常血清获得的CL的65%）。K-2和K-13型在大于65%的高范围和36%-65%的中间范围内均可被ACP调理吞噬。只有K-1、K-3、K-5、K-12和K-92型被ACP调理吞噬的程度较差（小于35%）。数据表明，大多数大肠杆菌K型可通过ACP被调理吞噬。大肠杆菌K-3、K-5、K-12和K-92型被ACP调理吞噬程度较差可能是这些细菌的毒力因子。
