目的  观察b型流感嗜血杆菌（Haemophilus influenzae type b，Hib）760705株在连续传代过程中的稳定性。方法  将Hib 760705株工作种子批菌种连续传代，对第5、第8、第10代Hib培养物进行全面检测，包括培养特性（X和V因子生长试验、卫星试验）、染色镜检、生化反应，以检测第5、第8、第10代Hib的生物学特性。同时采用血清凝集试验和聚合酶链反应荚膜分型方法进行b型荚膜多糖稳定性检测。结果  Hib 760705株工作种子批培养物在连续传代过程中具有典型的细菌学特性，能够稳定地产生b型荚膜多糖。结论  Hib 760705株有明确的来源和背景，可以稳定传代，具备作为Hib结合疫苗生产用候选菌株的条件。

Objective  To observe the passage stability of Haemophilus influenzae type b（Hib） strain 760705.  Methods  Hib strain 760705 was cultured for 10 passages from the working seed lot, and the subcultures of 5th, 8th and 10th passage were detected for biological charactristics comprehensively, including cultural characteristics(X and V factor test, satellite test), staining and microscopic examination, and biochemical reactions. Serological agglutination test and polymerase chain reaction for capsular typing were applied to confirm the generation stability of type b capsular polysaccharide. Results  The subcultures of Hib strain 760705 had typical bacteriological characteristics and capability of yielding type b capsular polysaccharide. Conclusions  Hib strain 760705 has a clear origin and background, and can be subcultured stably, thus suggesting that it can be a candidate strain for Hib conjugate vaccine production.