Razi Journal of Medical Sciences

Nowadays, group B streptococcus (GBS) is considered an important agent in early-onset infection in newborn infants. This is often transmitted to the child from the birth canal. Neonatal infection depends on degree of colonization of mother's vagina in labor. This study was conducted at two obstetrical teaching hospitals in Tehran (Shahid Akbarabadi and Mirza Kuchak Khan). Specimens were obtained from 200 women in labor befor rupture of membranes and directly inoculated into Todd-Hewith broth (THB) and selective Todd-Hewith broth (STHB) and incubated at 37'C and for 24 hours. Isolated strains were identified using conventional bacteriological methods. Then the degree of colonization was determined in positive GBS cultures. The results showed that the use of STHB increases the yield of positive GBS cultures. 17% of women were colonized with GBS. Degree of colonization in GBS carriers was determined. Colonization was light in 21%, moderate in 26%, heavy in 21% and very heavy in 32% of carriers (53% heavy and very heavy). These findings show that the risk of neonatal sepsis, due to transmission of GBS from the birth canal, should be considered seriously.