Screening of Streptococcus Agalactiae of Genitourinary Tract in the Late Pregnant Women in Guizhou Province and the Genetic Sequencing Analysis / 现代检验医学杂志

Objective To investigate the clonization of Streptococcus agalactiae (GBS) in the genitourinary tract of late pregnant women and perform the CAMP negative strains identification and analysis in Guizhou province.Methods Collected genital tract secretions from out-patient women in late pregnancy in the obstetric of Guizhou Provincial People's Hospital during the period from May 2016 to May 2017.Then the collected secretions conducted the bacteria culture and identification.The CAMP-negative GBS strain was furher identified by biochemical test and 16S rDNA sequence analysis,and cfb gene detection was conducted.Results Among the 3 794 samples,118 Streptococcus agalactiaes strains were isolated,and the positive rate was 3.11％.One of them was beta-hemolytic and the CFB gene was positive,but the CAMP test was negative,which was confirem to be Streptococcus agalactiae via 16S rDNA sequence analysis.The results showed that no GBS had been found to be resistant to Penicillin,Amoxicillin,Liniazolamine,Vancomycin,Cefotaxime.Cefepime and the strains with high drug resistence rate were followed by Erythromycin (81.3 ％),Clindamycin (62.7 ％),Levofloxacin (72.9 ％).Conclusion CAMP-negative was extremly rare in Streptococcus agalactiae,and only one strains of the 3 794 samples was isolated.Therefore,the clinical laboratory should be alert to CAMP negatie Streptococcus agalactiae for avoiding omission and providing more accurate test results for clinic.Also,the monitoring of drug-resistant strains of GBS should be strengthen.

Comparison of scpB gene and cfb gene polymerase chain reaction assays with culture on Islam medium to detect Group B Streptococcus in pregnancy.

Purpose: The purpose of the current study was to evaluate two low-costing PCR assays for rapid detection of Group B Streptococcus (GBS) in comparison to a pigment-based culture method. Materials and Methods: One-hundred and fifty vaginal swabs were collected from pregnant women at 35-40 weeks of gestation. Vaginal swabs were inoculated in selective enrichment broth medium, and examined using Islam medium, cfb PCR and scpB PCR assays. The demographic data were analysed to identify independent predictors of GBS colonization (age and gravidity), with GBS status as the dependent variable. Results: There was a significant association of age and gravidity with GBS colonization. GBS was detected in 25.3% of isolates by Islam medium, in 30.6% by using the cfb PCR assay and in 30% by using the scpB PCR assay. Conclusion: older pregnant women (≥30 years) and multigravida (>3 pregnancies) are at higher risk of GBS colonization. Both scpB-gene and cfb-gene-based PCR methods are highly sensitive techniques (100% sensitivity) compared to culture method. However, the specificities of the scpB and cfb PCR assays were 93.75 and 92.85%, respectively.