Laboratory support for prevention of perinatal group B streptococcal disease: commentary on the new guidelines on screening for group B streptococci during pregnancy

Laboratory diagnosis of urinary tract infections: Towards a BILULU consensus guideline

Urinary tract infections (UTI) are very common throughout life and account for the majority of the workload in the clinical microbiology laboratory. Clear instructions for the interpretation of urine cultures by the laboratory technicians are indispensable to obtain standardized, reliable, and clinically useful results. In literature, there is often a lack of evidence-based practice in processing urinary samples in the laboratory. In this consensus document, the BILULU Study Group presents a practical approach for the implementation of existing guidelines for the culture of urine in the microbiology laboratory and offers answers for issues where no clear solution is available in the guidelines.

Group B Streptococci Colonization in Pregnant Women: Is Screening Necessary?

Objectives

Group B Streptococcus (GBS) has been recognized as the leading cause of serious neonatal infections through mother—fetal vertical transmission in the west, however, in India, its spectrum is largely under estimated. The present study was carried out to find the incidence of rectovaginal carriage of GBS in parturient women, association with risk factors in mother and to study the neonatal outcome.

Materials and methods

A one year cross-sectional prospective study was carried out in 905 parturient women admitted at a tertiary care center meeting the selection criteria over a period of one year from June 2007 to May 2008. The inclusion criteria were all pregnant women admitted to the labor room after 35 ± 1 week of gestation. Rectal and vaginal swabs were taken and cultured on selective Todd-Hewitt broth medium followed by sub culture on blood agar and confirmation by Latex agglutination test from all the women meeting the inclusion criteria. The outcomes measured were the incidence, antenatal risk factors in mother and the neonatal outcome. Analysis was done using paired ‘t’ test, chi-square test and a p-value of <0.05 was taken as statistically significant.

Results

Incidence of group B Streptococcus (GBS) was 12.15% and detection rate was increased by 4.6% with the inclusion of rectal swabs for culture. GBS carriage was significantly increased with preterm birth (OR 8.3, 95% CI,1.1- 15.5), premature rupture of membranes (OR 7.5, 95% CI, 1.1- 13.4), prolonged duration of ruptured membranes more than 10 hours (OR 21, 95% CI,15.2-34.2) and intrapartum temperature more than 38°C(OR 3.1, 95% CI, 0.43-6.66). Birth weight less than 2.5 kg and neonatal intensive care admissions were significantly more (35.45%) in infants of GBS positive women.

Conclusion

GBS colonization was more frequent in women with risk factors. GBS pick up rate was increased by the inclusion of both rectal and vaginal swabs.

How to cite this article

Patil KP, Singla SS, Nagmoti MB, Swamy MK. Group B Streptococci Colonization in Pregnant Women: Is Screening Necessary? J South Asian Feder Obst Gynae 2013;5(2):64-67.

Evaluation of a new selective enrichment broth for detection of group B streptococci in pregnant women

Studies at two Brown Medical School-affiliated hospitals were undertaken to evaluate a new selective broth medium (GBS broth) and to compare it to the LIM broth currently used to culture for group B streptococci. Beta-hemolytic group B streptococci produce a carotenoid pigment that turns GBS broth an orange color. From a total of 580 pregnant women, duplicate vaginal-rectal swabs were collected at 35 to 37 weeks of gestation and cultured for group B streptococci, using either LIM broth (a selective broth containing antibiotics) or GBS broth for enrichment. Specimens were either transported to the laboratory or immediately placed in the respective enrichment broths and delivered to the laboratory. GBS broth medium had sensitivity, specificity, and positive and negative predictive values of 87.8, 100, 100, and 95.1% when planted in the laboratory and 90.3, 100, 100 and 97.6%, respectively, when inoculated at bedside. Use of GBS broth would satisfy Centers for Disease Control and Prevention requirements and would provide faster, more-sensitive, and cost-effective detection of group B streptococci in pregnant women.