Caracterización molecular en aislados chilenos de Streptococcus agalactiae

Rojo, Patricia; Araya, Pamela; Hormázabal, Juan Carlos; Maldonado, Aurora; Fernández, Jorge Onrubia

doi:10.4067/s0034-98872008000500009

Cited by 4 publications

(2 citation statements)

References 33 publications

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“…Nevertheless, high HylB levels or the presence of an intact hylB gene were also reported in isolates of S. agalactiae causing invasive disease. These contradictory reports point out that the exact involvement of HylB in systemic infections needs further investigations (Bohnsack et al, 2001;Musser et al, 1989;Rojo et al, 2008). IS1548 possesses another preferential insertion target just upstream of the lmb gene encoding a bifunctional laminin-binding protein/zinc-binding protein (Granlund et al, 1998(Granlund et al, , 2001; Fig.…”

Section: Mobile Genetic Element Of the Isas1 Familymentioning

confidence: 99%

Physiological impact of transposable elements encoding DDE transposases in the environmental adaptation of Streptococcus agalactiae

Fléchard

Gilot

2014

Microbiology

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We have referenced and described Streptococcus agalactiae transposable elements encoding DDE transposases. These elements belonged to nine families of insertion sequences (ISs) and to a family of conjugative transposons (TnGBSs). An overview of the physiological impact of the insertion of all these elements is provided. DDE-transposable elements affect S. agalactiae in a number of aspects of its capability to adapt to various environments and modulate the expression of several virulence genes, the scpB-lmB genomic region and the genes involved in capsule expression and haemolysin transport being the targets of several different mobile elements. The referenced mobile elements modify S. agalactiae behaviour by transferring new gene(s) to its genome, by modifying the expression of neighbouring genes at the integration site or by promoting genomic rearrangements. Transposition of some of these elements occurs in vivo, suggesting that by dynamically regulating some adaptation and/or virulence genes, they improve the ability of S. agalactiae to reach different niches within its host and ensure the 'success' of the infectious process.

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Section: Mobile Genetic Element Of the Isas1 Familymentioning

confidence: 99%

Physiological impact of transposable elements encoding DDE transposases in the environmental adaptation of Streptococcus agalactiae

Fléchard

Gilot

2014

Microbiology

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“…El porcentaje restante corresponde principalmente a los serotipos Ib y II (1,25,26). En Chile, los serotipos más prevalentes son el la, II y III, siendo el tipo III el más frecuentemente asociado a colonización vaginal en embarazadas y sepsis neonatal (27)(28)(29).…”

Section: Vacuna Anti Streptococcus Grupo Bunclassified

Profilaxis De Sepsis Neonatal Precoz Por Streptococcus Agalactiae (Grupo B) Basada en Vacunas: Revisión De La Literatura

Doren²,

O³

et al. 2008

Rev. chil. obstet. ginecol.

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El Streptococcus agalactiae o grupo B (SGB), es el principal agente de sepsis neonatal precoz. A pesar de los intentos de prevención de esta infección, aún no se logra la efectividad esperada. Es por esto que se ha intentado desarrollar una vacuna que pueda prevenir la mayoría de las patologías que esta bacteria produce, incluyendo la sepsis neonatal precoz y tardía. De esta manera se evitarían las limitaciones actuales de la profilaxis antibiótica. Los intentos de crear una vacuna han incluido la utilización de polisacáridos del SGB tanto puros como asociados a proteínas como el toxoide tetánico. También, se han usado proteínas específicas de la cápsula que tienen potencial efectividad como factores inmunogénicos. Las vacunas conjugadas son las más estudiadas en la actualidad, habiendo completado estudios clínicos en fase II, tanto en adultos sanos como en embarazadas. Al ser la sepsis neonatal una complicación grave aún no controlada óptimamente, la creación de una vacuna contra este patógeno sería de gran impacto en salud pública. Se presentan los diferentes tipos de vacunas desarrolladas y el estado de avance en el que se encuentran.

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Prevalence, serotypes and virulence genes of Streptococcus agalactiae isolated from pregnant women with 35–37 weeks of gestation

et al. 2021

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Background In pregnant women Streptococcus agalactiae (GBS) can be transmitted to newborn causing severe infections. It is classified into 10 serotypes (Ia, Ib, II-IX). The severity of neonatal disease is determined by the capsular serotype and virulence factors such as the polysaccharide capsule, encoded by the cps gene, protein C, which includes the Cα surface proteins (bca gene), Rib (rib gene) and Cβ (bac gene); the proteins Lmb (lmb gene), FbsB (fbsB gene), FbsA (fbsA gene), the cyl operon encoding a β-hemolysin (hylB gene), the CAMP factor (cfb gene) and the C5a peptidase (scpB gene). The aim of this work was to determine the degree of GBS colonization in pregnant women, the serotypes distribution and to investigate virulence-associated genes. Methods We worked with 3480 samples of vagino-rectal swabs of women with 35–37 weeks of gestation. The identification of the strains was carried out using conventional biochemical tests and group confirmatory serology using a commercial latex particle agglutination kit. Two hundred GBS strains were selected. Their serotype was determined by agglutination tests. The monoplex PCR technique was used to investigate nine virulence-associated genes (cps, bca, rib, bac, lmb, fbsB, fbsA, hylB and scpB). Results The maternal colonization was 9.09%. The serotypes found were: Ia (33.50%), III (19.00%), Ib (15.50%), II (14.00%), V (7.00%) and IX (5.50%). 5.50% of strains were found to be non-serotypeable (NT). The nine virulence genes investigated were detected simultaneously in 36.50% of the strains. The genes that were most frequently detected were scpB (100.00%), fbsA (100.00%), fbsB (100.00%), cylB (95.00%), lmb (94.00%) and bca (87.50%). We found associations between serotype and genes bac (p = 0.003), cylB (p = 0.02), rib (p = 0.01) and lmb (p < 0.001). Conclusions The frequency of vaginal-rectal colonization, serotypes distribution and associated virulence genes, varies widely among geographical areas. Therefore, epidemiological surveillance is necessary to provide data to guide decision-making and planning of prevention and control strategies.

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Caracterización molecular en aislados chilenos de Streptococcus agalactiae

Cited by 4 publications

References 33 publications

Physiological impact of transposable elements encoding DDE transposases in the environmental adaptation of Streptococcus agalactiae

Physiological impact of transposable elements encoding DDE transposases in the environmental adaptation of Streptococcus agalactiae

Profilaxis De Sepsis Neonatal Precoz Por Streptococcus Agalactiae (Grupo B) Basada en Vacunas: Revisión De La Literatura

Prevalence, serotypes and virulence genes of Streptococcus agalactiae isolated from pregnant women with 35–37 weeks of gestation

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