Guirguis N, Schneerson R, Bax A, Egan W, Robbins J B, Shiloach J, Orskov I, Orskov F, el Kholy A
J Exp Med. 1985 Dec 1;162(6):1837-51. doi: 10.1084/jem.162.6.1837.
Eleven Escherichia coli strains, crossreactive with the capsular polysaccharide (CPS) of Neisseria meningitidis group A (GrA), were detected among 645 stool isolates from healthy families in Cairo, Egypt. 10 of these strains were of the O107:K93:H27 or O107:K93:SP serotypes and may be considered descendents of a single bacterium or as a clone. The remaining crossreactive strain was of the O7:K51:H18 serotype. None of the 11 strains produced enterotoxins and none were enteroinvasive. The purified CPS of these E. coli strains, as well as a polysaccharide (PS) from B. pumilis, strain Sh17, precipitated with equine GrA (H49) antiserum. A partial identity between the E. coli K93, K51 and Sh17 PS on the one hand and the GrA CPS on the other was observed by double immunodiffusion when reacted against the H49 antiserum. Four K93 strains and one K51 strain were found among 320 E. coli strains from patients at the Clinical Center, National Institutes of Health, and three K93 strains were found in 105 stool samples from children in Copenhagen. The data from these three surveys suggest that these crossreactive E. coli are common organisms and could serve as a stimulus for "natural" GrA CPS antibodies. Quantitative precipitation analysis showed that K51, K93, and Sh17 PS precipitated 25, 46.8, and 50% of H49 antibodies, respectively. Absorption of H49 antiserum with the GrA CPS removed its precipitating activity with the E. coli K93, K51, and Sh17 PS. Absorption of H49 antiserum with either K51 CPS or Sh17 PS removed the homologous crossreactivity only, whereas K93 CPS absorbed both K93 and K51 reactivities. Antibodies, raised by intravenous injection of formalinized E. coli K93 or K51 cells into rabbits, precipitated with GrA CPS and were bactericidal against GrA meningococci. The crossreaction between the E. coli K93 and the GrA CPS was unexpected since these two CPS are compositionally so dissimilar.
在埃及开罗健康家庭的645份粪便分离物中，检测到11株与A群脑膜炎奈瑟菌（GrA）的荚膜多糖（CPS）发生交叉反应的大肠杆菌菌株。其中10株为O107:K93:H27或O107:K93:SP血清型，可被视为单一细菌的后代或一个克隆。其余的交叉反应菌株为O7:K51:H18血清型。这11株菌株均不产生肠毒素，也无侵袭性。这些大肠杆菌菌株的纯化CPS以及短小芽孢杆菌Sh17菌株的一种多糖（PS），能与马GrA（H49）抗血清发生沉淀反应。当与H49抗血清反应时，通过双向免疫扩散观察到大肠杆菌K93、K51和Sh17的PS一方面与GrA的CPS之间存在部分同一性。在美国国立卫生研究院临床中心患者的320株大肠杆菌菌株中发现了4株K93菌株和1株K51菌株，在哥本哈根儿童的105份粪便样本中发现了3株K93菌株。这三项调查的数据表明，这些交叉反应性大肠杆菌是常见的生物体，可作为“天然”GrA CPS抗体的刺激物。定量沉淀分析表明，K51、K93和Sh17的PS分别沉淀了25%、46.8%和50%的H49抗体。用GrA CPS吸收H49抗血清后，消除了其与大肠杆菌K93、K51和Sh17的PS的沉淀活性。用K51 CPS或Sh17 PS吸收H49抗血清仅消除了同源交叉反应性，而K93 CPS吸收了K93和K51的反应性。通过向兔静脉注射甲醛化的大肠杆菌K93或K51细胞产生的抗体，能与GrA CPS发生沉淀反应，并对GrA脑膜炎球菌具有杀菌作用。大肠杆菌K93与GrA CPS之间的交叉反应出乎意料，因为这两种CPS在组成上差异如此之大。
