Sialylation lessens the infectivity of Neisseria gonorrhoeae MS11mkC.

In a human challenge experiment, the infectivity of gonococci with sialylated lipooligosaccharide (LOS) was compared with the infectivity of gonococci with unsialylated LOS. Volunteers were intraurethrally inoculated with approximately 5000 sialylated or unsialylated piliated, non-opaque (P+Opa-, transparent) colony type gonococci, strain MS11mkC. Five (83%) of 6 volunteers inoculated with unsialylated gonococci became infected; however, only 1 of 5 volunteers became infected with sialylated gonococci. The unsialylated gonococcal infections, with a median incubation time of 62 h (range, 32-98), were similar to previously described experimental infections. Gonococci shed by infected volunteers showed a transition from the P+Opa- phenotype of the inoculation strain to the P+Opa+ (piliated, opaque) phenotype 12-60 h before onset of disease. The subject with sialylated gonococcus infection had an extended incubation period, showing a progressive increase in the number of organisms shed until he became symptomatic on day 6 after inoculation. These results show that gonococci with sialylated LOS are less infective than gonococci with unsialylated LOS.

在一项人体激发试验中，对具有唾液酸化脂寡糖（LOS）的淋球菌的感染性与具有非唾液酸化LOS的淋球菌的感染性进行了比较。志愿者被尿道内接种约5000个具有唾液酸化或非唾液酸化菌毛、非不透明（P⁺Opa⁻，透明）菌落型的淋球菌，菌株为MS11mkC。接种非唾液酸化淋球菌的6名志愿者中有5名（83%）被感染；然而，接种唾液酸化淋球菌的5名志愿者中只有1名被感染。非唾液酸化淋球菌感染的中位潜伏期为62小时（范围为32 - 98小时），与先前描述的实验性感染相似。被感染志愿者排出的淋球菌在发病前12 - 60小时显示出从接种菌株的P⁺Opa⁻表型转变为P⁺Opa⁺（有菌毛、不透明）表型。感染唾液酸化淋球菌的受试者潜伏期延长，在接种后第6天出现症状之前，排出的病原体数量逐渐增加。这些结果表明，具有唾液酸化LOS的淋球菌比具有非唾液酸化LOS的淋球菌感染性更低。