OR01: The role of Streptococcus agalactiae cadD in metal efflux, survival in macrophages, and ascending vaginal infection during pregnancy

2019 ◽  
Vol 81 (S1) ◽  
pp. 26-26
Keyword(s):  
Streptococcus Agalactiae ◽  
Vaginal Infection ◽  
Metal Efflux

Staphylococcus aureusisogenic mutant, deficient in toxic shock syndrome toxin-1 but not staphylococcal enterotoxin A production, exhibits attenuated virulence in a tampon-associated vaginal infection model of toxic shock syndrome

1999 ◽  
Vol 45 (3) ◽  
pp. 250-256
Author(s):  
Monica L De Boer ◽  
Winnie WS Kum ◽  
Anthony W Chow
Keyword(s):  
Weight Loss ◽  
Toxic Shock Syndrome ◽  
Staphylococcal Enterotoxin ◽  
Aureus Strain ◽  
Infection Model ◽  
Staphylococcal Enterotoxin A ◽  
Toxic Shock ◽  
Vaginal Infection ◽  
Toxic Shock Syndrome Toxin

Since menstrual toxic shock syndrome (MTSS) is associated with a predominant clone of Staphylococcus aureus which produces both toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxin A (SEA), we sought to clarify the role of TSST-1 in a tampon-associated vaginal infection model in New Zealand White (NZW) rabbits, using isogenic tst+/sea+S. aureus mutants in which tst was inactivated by allelic replacement. Rabbits infected with the tst-/sea+strain became ill within 3 days, with fever, weight loss, conjunctival hyperemia, and lethargy. Mortality was significantly higher with the tst+/sea+strain compared to its tst-/sea+isogenic derivative (4/13 vs. 0/14; p < 0.05, Fisher's exact test, 2-tailed). Mean fever index was higher (p < 0.005; t test, 2-tailed) and weight loss more sustained among survivors in the tst+/sea+group. Furthermore, culture filtrates from the tst+/sea+strain induced a significantly greater response in mitogenesis and TNFalpha secretion from rabbit splenocytes in vitro compared to the tst-/sea+isogenic derivative. Thus, regardless of the role of SEA, TSST-1 significantly contributed to both morbidity and mortality in this tampon-associated vaginal infection model in NZW rabbits. This is the first demonstration of the potential role of TSST-1 and SEA in the pathogenesis of MTSS with a MTSS-associated clinical S. aureus strain in a relevant animal model.Key words: toxic-shock syndrome toxin-1, superantigens, rabbit model.

scholarly journals Impact of lgt mutation on lipoprotein biosynthesis and in vitro phenotypes of Streptococcus agalactiae

Microbiology ◽  
2009 ◽  
Vol 155 (5) ◽  
pp. 1451-1458 ◽  
Author(s):  
Beverley A. Bray ◽  
Iain C. Sutcliffe ◽  
Dean J. Harrington
Keyword(s):  
Oxidative Stress ◽  
Streptococcus Agalactiae ◽  
Molecular Basis ◽  
Cell Envelope ◽  
Host Cells ◽  
Human Endothelial Cells ◽  
Increased Sensitivity ◽  
Group B

Although Streptococcus agalactiae, the group B Streptococcus, is a leading cause of invasive neonatal disease worldwide the molecular basis of its virulence is still poorly understood. To investigate the role of lipoproteins in the physiology and interaction of this pathogen with host cells, we generated a mutant S. agalactiae strain (A909ΔLgt) deficient in the Lgt enzyme and thus unable to lipidate lipoprotein precursors (pro-lipoproteins). The loss of pro-lipoprotein lipidation did not affect the viability of S. agalactiae or its growth in several different media, including cation-depleted media. The processing of two well-characterized lipoproteins, but not a non-lipoprotein, was clearly shown to be aberrant in A909ΔLgt. The mutant strain was shown to be more sensitive to oxidative stress in vitro although the molecular basis of this increased sensitivity was not apparent. The inactivation of Lgt also resulted in changes to the bacterial cell envelope, as demonstrated by reduced retention of both the group B carbohydrate and the polysaccharide capsule and a statistically significant reduction (P=0.0079) in A909ΔLgt adherence to human endothelial cells of fetal origin. These data confirm that failure to process lipoproteins correctly has pleiotropic effects that may be of significance to S. agalactiae colonization and pathogenesis.

scholarly journals Efek Kefir Terhadap Kadar Superokdidase Dismutase, Malondialdehyde Pada Mencit Balb/C Diinduksi Streptococcus Agalactiae

2021 ◽  
Vol 5 (3) ◽  
pp. 101-110
Author(s):  
Mustika Dewi ◽  
◽  
Mega Ulfah ◽  
Keyword(s):  
Streptococcus Agalactiae ◽  
Pathogenic Bacteria ◽  
Neonatal Morbidity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Vaginal Mucosa ◽  
Control Group Design ◽  
Inflammatory Parameters ◽  
Significant Difference

Streptococcus agalactiae are pathogenic bacteria which cause vaginal infection. Vaginal and cervical infections in pregnant women can reduce elasticity of the membranes that cause premature rupture of membranes. This can also impact to neonatal morbidity and mortality in first week of birth. Kefir is known as a probiotic that can act as an immunomodulator. The role of kefir is believed to improve the immune system. The role of kefir in preventing infection is still rarely studied, especially as an immunomodulator and in reducing the number of pathogenic bacteria.This study aimed to evaluate superoxide dismutase (SOD) level, Malondialdehyde (MDA) level, and the population of the colonization Streptococcus agalactiae in BALB-C mice fed kefir. This study was true experimental with post test only control group design. Sample was BALB-C mice induced by Streptococcus agalactiae. SOD and MDA level was examined by enzyme-linked immunosorbent assay (ELISA) and Streptococcus agalactiae identification by colony count. The results of the one-way ANOVA analysis showed there was no significant differences between all groups for SOD levels (P 0.393). In the level of MDA there was also no difference between all groups (P 0.204). Whereas in the number of Streptococcus agalactiae colonies there was a significant difference (P 0.000) with the smallest number of colonies found at dose of 0.5 ml / day. Conclusion: kefir as a probiotic drink did not affect to the SOD and MDA level of BALB/ C mice induced by Streptococcus agalactiae, but kefir affected to number of Streptococcus agalactiae colonies. Further research needs to show the relation of kefir as probiotics with proinflammatory and other anti-inflammatory parameters such as interleukin and immunological vaginal mucosa.

Role of the Streptococcus agalactiae ClpP serine protease in heat-induced stress defence and growth arrest

Microbiology ◽  
2003 ◽  
Vol 149 (2) ◽  
pp. 407-417 ◽  
Author(s):  
Shamila Nair ◽  
Claire Poyart ◽  
Jean-Luc Beretti ◽  
Herrique Veiga-Fernandes ◽  
Patrick Berche ◽  
...  
Keyword(s):  
Serine Protease ◽  
Streptococcus Agalactiae ◽  
Growth Arrest ◽  
Induced Stress

scholarly journals A Perspective on the Potential Zoonotic Role of Streptococcus agalactiae: Searching for a Missing Link in Alternative Transmission Routes

2018 ◽  
Vol 9 ◽  
Author(s):  
Ana C. N. Botelho ◽  
Ana F. M. Ferreira ◽  
Sergio E. L. Fracalanzza ◽  
Lucia M. Teixeira ◽  
Tatiana C. A. Pinto
Keyword(s):  
Streptococcus Agalactiae ◽  
Missing Link

scholarly journals Defining the Role of theStreptococcus agalactiaeSht-Family Proteins in Zinc Acquisition and Complement Evasion

2019 ◽  
Vol 201 (8) ◽  
Author(s):  
P. Moulin ◽  
V. Rong ◽  
A. Ribeiro E Silva ◽  
V. G. Pederick ◽  
E. Camiade ◽  
...  
Keyword(s):  
Human Blood ◽  
Streptococcus Agalactiae ◽  
Metal Ion ◽  
Binding Proteins ◽  
Factor H ◽  
Zinc Uptake ◽  
Zinc Homeostasis ◽  
Content Type

ABSTRACTStreptococcus agalactiaeis not only part of the human intestinal and urogenital microbiota but is also a leading cause of septicemia and meningitis in neonates. Its ability to cause disease depends upon the acquisition of nutrients from its environment, including the transition metal ion zinc. The primary zinc acquisition system of the pathogen is the Adc/Lmb ABC permease, which is essential for viability in zinc-restricted environments. Here, we show that in addition to the AdcCB transporter and the three zinc-binding proteins, Lmb, AdcA, and AdcAII,S. agalactiaezinc homeostasis also involves two streptococcal histidine triad (Sht) proteins. Sht and ShtII are required for zinc uptake via the Lmb and AdcAII proteins with apparent overlapping functionality and specificity. Both Sht-family proteins possess five-histidine triad motifs with similar hierarchies of importance for Zn homeostasis. Independent of its contribution to zinc homeostasis, Sht has previously been reported to bind factor H leading to predictions of a contribution to complement evasion. Here, we investigated ShtII to ascertain whether it had similar properties. Analysis of recombinant Sht and ShtII reveals that both proteins have similar affinities for factor H binding. However, neither protein aided in resistance to complement in human blood. These findings challenge prior inferences regarding thein vivorole of the Sht proteins in resisting complement‐mediated clearance.IMPORTANCEThis study examined the role of the two streptococcal histidine triad (Sht) proteins ofStreptococcus agalactiaein zinc homeostasis and complement resistance. We showed that Sht and ShtII facilitate zinc homeostasis in conjunction with the metal-binding proteins Lmb and AdcAII. Here, we show that the Sht-family proteins are functionally redundant with overlapping roles in zinc uptake. Further, this work reveals that although the Sht-family proteins bind to factor Hin vitrothis did not influence survival in human blood.

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