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Updated: Aug 5, 2026

A Murine Model of Group B Streptococcus Vaginal Colonization
Published on: November 16, 2016
Descriptive analysis of genital colonization across gestational trimesters in pregnant women with different obstetric
Carolina Pereira Andrade1, Camila Marconi2, Márcia Guimarães da Silva3
1Universidade Federal do Paraná CuritibaPR Brazil Universidade Federal do Paraná Curitiba, PR, Brazil.
Objective:
The aim of this study was to assess the Ureaplasma parvum variation of genital colonization during pregnancy with an exploratory approach among women with term and preterm birth histories.
Methods:
Prospective case-control study of 24 pregnant women with history of full-term pregnancy and 26 pregnant women with history of prematurity whose endpoint was to assess the colonization pattern of these agents with a vaginal/cervical sample collected at the beginning of each trimester of gestation. Collected data: sociodemographic characteristics, previous diseases, gynecological and obstetric history, and microorganisms in vaginal secretion samples by real-time polymerase chain reaction (PCR).
Results:
The overall number of cases positive for at least one microorganism was 18 (36.0%). A significantly higher positivity rate was observed in the second and third trimesters in both study groups compared with the first trimester (p<0.001). The microorganisms identified in the vaginal environment were Ureaplasma parvum (66.6%), Mycoplasma hominis (16.7%), and both (16.7%), and the frequency of both these microorganisms was comparable in both groups at each pregnancy trimester (p for all = nonsignificant), but with a difference between the trimesters. Prematurity in the current pregnancy occurred in a single case (6.7%) in a pregnant woman without history of prematurity in the previous pregnancy (p=1.00).
Conclusion:
The most frequently identified microorganism was Ureaplasma parvum, and the overall incidence of positive cases including all microorganisms was 36.0%. Although Ureaplasma parvum was the most frequently identified microorganism, the sample was not powered to assess its association with prematurity.
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