Subculture on Islam agar: rapid and reliable method to detect group b streptococci colonization status

Background: Various methods have been used to detect the colonization status of near term pregnant females but there is lack of consensus on the most appropriate method. In this study we have evaluated three different techniques in terms of their reliability and easiness to perform

---

Objective: The objective of our study was to determine the validity of 3 laboratory methods namely direct culture on selective blood agar, direct culture on Islam agar and subculture after enrichment with Lim broth on Islam agar in diagnosis of group B streptococcus [Streptococcus agalactiae] [GBS] in near term pregnant females

---

Materials and Methods: This prospective study was conducted at microbiology section of department of the Pathology, King Edward Medical University and outpatient department of Lady Atchison and Lady Willington Hospital, Lahore. 200 near term, pregnant women of all ages between 35 to 37 weeks of gestation were included in the study. Swabs from the vaginal introitus were subjected to analysis by culture on 4 medias and sensitivity and specificity were calculated for each media against the gold standard

---

Results: On gold standard media 32 cases were found to be positive for GBS. The prevalence was 16%. The calculated sensitivity and specificity for different techniques were; Blood agar [93.3%, 98%], Islam Agar [93.3%, 98%] and LIM enriched Islam Agar [100%, 100%]

---

Conclusion: Subculture on Islam Agar after LIM enrichment is superior to other techniques in terms of its performance and cost related issues