ABSTRACT
Aims@#Maternal vaginal Group B Streptococcus (GBS) colonization is considered a risk factor for preterm delivery and, consequently, neonatal infections. Previous studies have portrayed the important roles of these virulence factors, including hemolytic pigment, hyaluronidase (HylB), serine-rich protein (Srr) and bacterial surface adhesion of GBS (BsaB) in mediating GBS colonization and intrauterine ascending infection, causing preterm delivery. This study aimed to investigate the association between mRNA expression of virulence genes in GBS isolates obtained from symptomatic pregnant women and preterm delivery.@*Methodology and results@#GBS isolates were obtained from high vaginal swabs of 40 symptomatic pregnant women of gestational age of less than 37 weeks. RNA was extracted from these GBS isolates and RT-qPCR was performed to determine the relative mRNA expression of GBS virulence genes, including CylE (encode enzyme required for the biosynthesis of the hemolytic pigment), HylB, Srr-1 and BsaB. Socio-demographic details and obstetric history were not found to be associated with the delivery outcomes of these women. The GBS isolates from symptomatic pregnant women who delivered prematurely showed a higher expression of CylE gene and a trend towards an elevated expression of HylB gene compared to women with term delivery. Meanwhile the expression of both Srr-1 and BsaB genes was similar between symptomatic pregnant women who had term or preterm delivery.@*Conclusion, significance and impact of study@#The results suggest that following vaginal colonization, both CylE and HylB genes are likely to contribute to intrauterine ascending infection and inflammation, leading to preterm delivery in humans. These virulence factors may be targeted for the pre-clinical stages of vaccine development or therapeutic intervention.
Subject(s)
Pregnant WomenABSTRACT
Group B Streptococcus ( GBS) is a leading infectious cause of adverse pregnancy out-comes such as preterm birth. GBS colonizes the vagina during pregnancy and can ascend into the uterus and then infect the fetus. It encodes a series of virulence factors such as adhesion and invasion factors, hemolytic pigments and hyaluronidase, which are important to vaginal colonization and immune evasion. Immune re-sponses to GBS cause the release of a multiple of inflammatory mediators, leading to the premature rupture of membranes, preterm birth and fetal injury. This paper reviews the pathogenesis of GBS vaginal colonization and ascending infection causing adverse pregnancy outcomes.
ABSTRACT
The aim of our study was to evaluate maternal colonization with Group B Streptococci (GBS) which may predispose to adverse neonatal outcome. The study was carried out in a tertiary care hospital in Mangalore for a duration of one year. Duplicate sterile swabs of all samples from vagina of antenatal cases (35 to 37 wks gestation) who visited the Gynaecology OPD and wards were collected. Samples were transported without delay and cultured and identified by biochemical and agglutination tests. The antibiogram for the isolates were performed as per CLSI guidelines. Of the 349 antenatal cases screened during the third trimester for GBS colonization, 29 (8.31%) were found to harbour Group B Streptococcus. The different rates of colonization of GBS in the population has led to the conclusion of potential hazards to neonates among pregnant women warranting mandatory screening of not only vaginal but also urine and rectal samples to get a more reliable result leading to better early intrapartum treatment and safer neonatal outcomes.
ABSTRACT
Objective To report a case of vaginal colonization due to Trichosporon inkin. Methods A 34-year-old female presented with increased vaginal discharge accompanied by abnormal odor for 2 months. Clinical laboratory examination was carried out. Cultures of vaginal discharge yielded yeast-like colony. Subsequently, the isolate underwent the following mycological examinations: purification, slide micro-culture, temperature test, urea enzyme test, biochemistry identification, antifungal susceptibility test, and gene sequencing. Results Gynecological examination revealed white homogeneous secretions attached to mucous membrane of the vagina. Nugent scores of vaginal discharge amounted to 5-6. Two rounds of culture of vaginal discharge resulted in stramineous, reductus and yeast-like colony. The isolate could grow in 42 ℃. Appressorium on the top of hypha and typical sarcinae formed in slide microculture of corn agar, and yeast malt agar was the optimal growth medium for it. Urea enzyme test was positive. API 20C AUX biochemical test and gene sequencing revealed that the isolate was consistent with Trichosporon inkin. The isolate was sensitive to amphotericin B and azoles such as clotrimazole and fluconazole, but resistant to flucytosine and caspofungin. Conclusions It is the first report of vaginal colonization due to T. Inkin in China. The accu-rate identification of T. Inkin relies on synthetic analysis of phenotype characteristics, biochemistry test and molecular sequencing.
ABSTRACT
Aims: To study the risk factors associated with Escherichia coli vaginal colonization in two population groups that attended primary health care centers. Study groups and methods: One thousand thirty women with active sexual life and vaginitis diagnosis were studied. The study population was divided in two groups. Group 1, included 480 patients from José Castro Villagrana health center (SS) and group 2, included 550 patients from Ignacio Chávez family health center (ISSSTE) from México City. Vaginal specimen was taken from all patients. Statistical analysis was made using Fisher's exact test or chi-square to analize the frequency, with a significance level of 95%. For the association of variables we used the reason of crosstabulations with confidence intervals of 95%. Results: In both groups menopause, hysterectomy, age and menstrual cycle were associated with Escherichia coli colonization. There was no association with use of vaginal tampons, application of douches and sexual behavior. Conclusions: Vaginal colonization with E. coli was associated with hormonal factors. Sexual behavior did not implicate a higher risk of colonization. Probably pregnancy could be a protective factor against the colonization of this bacterium
Objetivo: Reconocer los factores de riesgo asociados a la colonización vaginal por Escherichia coli entre dos grupos de poblaciones que acuden a consulta en el primer nivel de asistencia médica. Pacientes y método: Se tomó exudado vaginal a 1 030 mujeres de dos grupos de estudio: el grupo 1 lo integraron 480 pacientes del Centro de Salud Dr. José Castro Villagrana, Secretaría de Salud del Distrito Federal (SSDF); en el grupo 2 participaron 550 pacientes de la Clínica de Medicina Familiar Dr. Ignacio Chávez, Instituto de Seguridad y Servicios Sociales para los Trabajadores del Estado (ISSSTE). Todas las participantes tenían vida sexual activa y diagnóstico de vaginitis. Para el análisis de frecuencias se utilizó la prueba de chi cuadrado o la exacta de Fisher, con nivel de significación del 95%. Para la asociación de variables se calculó la razón de productos cruzados e intervalos de confianza del 95%. Resultados: Para los dos grupos, el estado de climaterio, la histerectomía, edad mayor de 45 años y la toma de la muestra en la fase menstrual presentaron las prevalencias más altas, y en la mayoría con diferencias estadísticas significativas. No se encontró asociación con el uso o la aplicación de duchas y tampones vaginales. Tampoco se encontró asociación con factores que implican conducta sexual. Conclusiones: La colonización vaginal por Escherichia coli está condicionada principalmente por factores de tipo hormonal; en contraste, la conducta sexual no define dicha colonización. Con base en los antecedentes, es importante que el embarazo resulte un factor protector para la colonización de la bacteria