Intervention On Colonization Of Escherichia Coli K1 And Group B Streptococcus In The Gut And Vaginal Of Pregnant Women By Orally Administrated Probiotics And Its Effect On The Vaginal Microecology Of Pregnant Women

1.Research background and purposeThe most common form of neonatal central nervous system infection is bacterial meningitis.At present,B Streptococcus(GBS)and Escherichia coli(E.coli)are the most common pathogens causing neonatal bacterial meningitis.The most important risk factor for progression of invasive neonatal infection is the colonization of the maternal reproductive tract or gastrointestinal tract.Clinically,pregnant women carrying GBS are mainly based on antibiotic prophylaxis during production.However,the application of antibiotics reduces the neonatal resistance to other infections,resulting in E.coli K1 becoming the main pathogen of bacterial meningitis in newborns.E.coli K1 is mainly derived from the mother’s intestine for the reason of special physical status of pregnant women,E.coli K1 colonized in the intestine is easily transferred to vagina,leading to the acquire infection of newborn when passing through the birth canal.Once invading E.coli K1 is colonized in the neonatal intestine,it has the opportunity to undergo metastasis into the blood,eventually passing through the blood-brain barrier to initiate meningitis.Therefore,it is vital to inhibit the intestinal adhesion and invasion prosess of pathogenic bacteria in the prevention of neonatal bacterial meningitis in the pregnant woman stage.Experimental results in vitro and vivo have proven that oral administration of probiotics has positive effects on bacterial infection,but there is still lack of clinical data.Vaginal microecological imbalance during pregnancy may cause adverse outcomes in perinatal infants.With the in-depth understanding of the human micro-ecological system,the role of probiotics in the micro-ecological system(such as the reproductive tract)has gradually applied to the treatment of bacterial infection universally.2.Research methods2.1 Vaginal and rectal secretion specimens were collected from 2539 health pregnant women in Guangdong from 2011 to 2017.First,47 healthy pregnant women involved were randomly divided into the 2 groups.The treatment group received probiotics,while the control group without.Real-time PCR was used to detect the quantitative colonization changes of E.coli K1 in the two groups thereafter.2.2 50 pregnant women subjected to the GBS screening by PCR were randomly divided into 2 groups.Later,real-time PCR was used to detect the quantitative changes of GBS in the two groups.real-time PCR was used to detect GBS in the genital tract and rectal specimens for recording the colonization of GBS.2.3 Using the vaginal microecology comprehensive evaluation method to screen the vaginal microecological status of pregnant women.50 patients with vaginal microecological imbalance but no clinical symptoms were selected for the study.Patients were randomly divided into treatment group and control group,treatment group accepting the treatment of probiotics,while the control group didn’t accept.Evaluating the microecological status of the two groups using a comprehensive assessment of vaginal microecology.3.Results3.1 With no statistical differences between the groups in term of age,multipara proportion and level of education(P>0.05).3.2 the colonization of E.coli K1 in the treatment group declined dramatically(Fl=32.866,P<0.001).Women in the oral probiotics group have lower level of colonization of E.coli K1(F=41.546,P<0.001)3.3 The results suggest that oral administration of probiotics may inhibit the colonization of GBS in the intestines and vaginas of pregnant women.Finally,the GBS carrier rate of the pregnant woman was 8.07%by PCR.3.4 Through the vaginal microecosystem comprehensive evaluation method,vaginal microecological imbalance rate is 38.4%.There was no difference between the observation group and the control group in vaginal microecological recovery rates.4.Conclusion4.1 The GBS carrier rate of the screening pregnant women(35 weeks to 37 weeks of gestation)in Guangdong was 8.07%.4.2 The results suggest that oral administration of probiotics to pregnant women may inhibit the colonization of group B Streptococcus and E.coli K1 in the genital tract and intestine of these women,which may prevent neonatal bacterial meningitis in newborns as a result of hematogenous spread.4.3 Oral administration of probiotics to pregnant women may restore the normal vaginal microecology of those women by extending treatment duration.