A total of 242 samples from distal vaginal segment and around crissum and 15 midstream urine samples were collected among 35-37-week pregnant women. The samples were inoculated directly and with one more step of GBS enrichment broth on Colombia blood agar and GBS screening media, respectively, and the growth of GBS in the 2 kinds of media was observed.

As for inoculating directly, the detection rates of GBS in Colombia blood agar medium for 24 h and 48 h were 7.39% (19/257), and the 24 h and 48 h detection rates of GBS in GBS screening medium were 5.45%(14/257) and 7.39%(19/257), respectively. As for inoculating with one more step of GBS enrichment broth, for neither 24 h nor 48 h, the detection rate of GBS in Colombia blood agar medium was 9.73%(25/257), and the detection rate in GBS screening medium was 8.95%(23/257), both of which had an evident increasing comparing with the former one. There was no statistical significance for the detection rate between the 2 kinds of media (P>0.05).

By enriching 18 h-24 h in GBS enrichment broth, followed by inoculating in GBS screening medium or Colombia blood agar medium, the growth of GBS from clinical samples in media could be observed just after 24 h, and this method has simple recognition ability for GBS and can improve GBS positive detection rate.