scholarly journals Identification of Major Outer Surface Proteins of Streptococcus agalactiae

2002 ◽  
Vol 70 (3) ◽  
pp. 1254-1259 ◽  
Author(s):  
Martin J. G. Hughes ◽  
Joanne C. Moore ◽  
Jonathan D. Lane ◽  
Rebecca Wilson ◽  
Philippa K. Pribul ◽  
...  
Keyword(s):  
Outer Surface ◽  
Streptococcus Agalactiae ◽  
Expression System ◽  
Group B Streptococcus ◽  
Phosphoglycerate Kinase ◽  
Peptide Sequencing ◽  
Surface Proteins ◽  
Outer Surface Proteins ◽  
Group B

ABSTRACT To identify the major outer surface proteins of Streptococcus agalactiae (group B streptococcus), a proteomic analysis was undertaken. An extract of the outer surface proteins was separated by two-dimensional electrophoresis. The visualized spots were identified through a combination of peptide sequencing and reverse genetic methodologies. Of the 30 major spots identified as S. agalactiae specific, 27 have been identified. Six of these proteins, previously unidentified in S. agalactiae, were sequenced and cloned. These were ornithine carbamoyltransferase, phosphoglycerate kinase, nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase, purine nucleoside phosphorylase, enolase, and glucose-6-phosphate isomerase. Using a gram-positive expression system, we have overexpressed two of these proteins in an in vitro system. These recombinant, purified proteins were used to raise antisera. The identification of these proteins as residing on the outer surface was confirmed by the ability of the antisera to react against whole, live bacteria. Further, in a neonatal-animal model system, we demonstrate that some of these sera are protective against lethal doses of bacteria. These studies demonstrate the successful application of proteomics as a technique for identifying vaccine candidates.

scholarly journals Cellular Management of Zinc in Group B Streptococcus Supports Bacterial Resistance against Metal Intoxication and Promotes Disseminated Infection

mSphere ◽  
2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Matthew J. Sullivan ◽  
Kelvin G. K. Goh ◽  
Glen C. Ulett
Keyword(s):  
Streptococcus Agalactiae ◽  
Bacterial Resistance ◽  
Group B Streptococcus ◽  
Systemic Infection ◽  
Metal Stress ◽  
Mechanisms Of Resistance ◽  
Content Type ◽  
Group B ◽  
Zn Stress

ABSTRACT Zinc is an essential trace element for normal bacterial physiology but, divergently, can intoxicate bacteria at high concentrations. Here, we define the molecular systems for Zn detoxification in Streptococcus agalactiae, also known as group B streptococcus, and examine the effects of resistance to Zn stress on virulence. We compared the growth of wild-type bacteria and mutants deleted for the Zn exporter, czcD, and the response regulator, sczA, using Zn-stress conditions in vitro. Macrophage antibiotic protection assays and a mouse model of disseminated infection were used to assess virulence. Global bacterial transcriptional responses to Zn stress were defined by RNA sequencing and quantitative reverse transcription-PCR. czcD and sczA enabled S. agalactiae to survive Zn stress, with the putative CzcD efflux system activated by SczA. Additional genes activated in response to Zn stress encompassed divalent cation transporters that contribute to regulation of Mn and Fe homeostasis. In vivo, the czcD-sczA Zn management axis supported virulence in the blood, heart, liver, and bladder. Additionally, several genes not previously linked to Zn stress in any bacterium, including, most notably, arcA for arginine deamination, also mediated resistance to Zn stress, representing a novel molecular mechanism of bacterial resistance to metal intoxication. Taken together, these findings show that S. agalactiae responds to Zn stress by sczA regulation of czcD, with additional novel mechanisms of resistance supported by arcA, encoding arginine deaminase. Cellular management of Zn stress in S. agalactiae supports virulence by facilitating bacterial survival in the host during systemic infection. IMPORTANCE Streptococcus agalactiae, also known as group B streptococcus, is an opportunistic pathogen that causes various diseases in humans and animals. This bacterium has genetic systems that enable zinc detoxification in environments of metal stress, but these systems remain largely undefined. Using a combination of genomic, genetic, and cellular assays, we show that this pathogen controls Zn export through CzcD to manage Zn stress and utilizes a system of arginine deamination never previously linked to metal stress responses in bacteria to survive metal intoxication. We show that these systems are crucial for survival of S. agalactiae in vitro during Zn stress and also enhance virulence during systemic infection in mice. These discoveries establish new molecular mechanisms of resistance to metal intoxication in bacteria; we suggest these mechanisms operate in other bacteria as a way to sustain microbial survival under conditions of metal stress, including in host environments.

scholarly journals In VitroActivity of Solithromycin against Erythromycin-Resistant Streptococcus agalactiae

2013 ◽  
Vol 58 (3) ◽  
pp. 1693-1698 ◽  
Author(s):  
Giorgio Piccinelli ◽  
Prabhavathi Fernandes ◽  
Carlo Bonfanti ◽  
Francesca Caccuri ◽  
Arnaldo Caruso ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Group B Streptococcus ◽  
Phenotypic Characterization ◽  
Content Type ◽  
Resistant Strains ◽  
Group B ◽  
Microdilution Broth

ABSTRACTThein vitroantibacterial activity of solithromycin (CEM-101) against macrolide-resistant isolates (n= 62) ofStreptococcus agalactiae(group B streptococcus [GBS]) was determined. Phenotypic characterization of macrolide-resistant strains was performed by double-disc diffusion testing. A multiplex PCR was used to identify theerm(B),erm(TR), andmef(A/E) genes, capsular genotypes, and alpha-like (Alp) protein genes from the GBS strains. Determination of MIC was carried out using the microdilution broth method. The Etest method was used for penicillin, azithromycin, clarithromycin, and erythromycin. Solithromycin had a MIC50of ≤0.008 μg/ml and a MIC90of 0.015 μg/ml against macrolide-susceptibleS. agalactiae. These MICs were lower than those displayed by penicillin (MIC50of 0.032 μg/ml and MIC90of 0.047 μg/ml), the antibiotic agent of choice for prophylaxis and treatment of GBS infections. Against macrolide-resistantS. agalactiae, solithromycin had a MIC50of 0.03 μg/ml and a MIC90of 0.125 μg/ml. Againsterm(B) strains, solithromycin had a MIC50of 0.03 μg/ml and a MIC90of 0.06 μg/ml, while againstmef(A) strains, it had a MIC50of 0.03 μg/ml and a MIC90of 0.125 μg/ml. Most erythromycin-resistant GBS strains were of serotype V (64.5%) and associated significantly withalp2-3. Moreover, a statistically significant association was observed between the constitutive macrolide-lincosamide-streptogramin B resistance (cMLSB) phenotype and theerm(B) gene-carrying strains, thealp2-3gene and the M phenotype, and themef(A/E) gene andepsilon. Overall, our results show that solithromycin had lower or similar MICs than penicillin and potent activity against macrolide-resistant strains independent of their genotype or phenotype, representing a valid therapeutic alternative where β-lactams cannot be used.

scholarly journals Cellular management of Zinc in group B Streptococcus supports bacterial resistance against metal intoxication and promotes disseminated infection

2021 ◽  
Author(s):  
Matthew J. Sullivan ◽  
Kelvin G. K. Goh ◽  
Glen C. Ulett
Keyword(s):  
Streptococcus Agalactiae ◽  
Bacterial Resistance ◽  
Group B Streptococcus ◽  
Systemic Infection ◽  
Metal Stress ◽  
Mechanisms Of Resistance ◽  
Disseminated Infection ◽  
Group B ◽  
Zn Stress

AbstractZinc (Zn) is an essential trace element for normal bacterial physiology but divergently, can intoxicate bacteria at high concentrations. Here, we define the molecular systems for Zn detoxification in Streptococcus agalactiae, also known as group B Streptococcus, and examine the effects of resistance to Zn stress on virulence. We compared the growth of wild-type bacteria and mutants deleted for the Zn exporter, czcD, and the response regulator, sczA, using Zn-stress conditions in vitro. Macrophage antibiotic protection assays and a mouse model of disseminated infection were used to assess virulence. Global bacterial transcriptional responses to Zn stress were defined by RNA-sequencing and qRTPCR. czcD and sczA enabled S. agalactiae to survive Zn stress, with the putative CzcD efflux system activated by SczA. Additional genes activated in response to Zn stress encompassed divalent cation transporters that contribute to regulation of Mn and Fe homeostasis. In vivo, the czcD-sczA Zn-management axis supported virulence in the blood, heart, liver and bladder. Additionally, several genes not previously linked to Zn stress in any bacterium, including most notably, arcA for arginine deamination also mediated resistance to Zn stress; representing a novel molecular mechanism of bacterial resistance to metal intoxication. Taken together, these findings show that S. agalactiae responds to Zn stress by sczA regulation of czcD, with additional novel mechanisms of resistance supported by arcA, encoding arginine deaminase. Cellular management of Zn stress in S. agalactiae supports virulence by facilitating bacterial survival in the host during systemic infection.Importance StatementStreptococcus agalactiae, also known as group B streptococcus, is an opportunistic pathogen that causes various diseases in humans and animals. This bacterium has genetic systems that enable Zinc (Zn) detoxification in environments of metal stress, but these systems remain largely undefined. Using a combination of genomic, genetic and cellular assays we show that this pathogen controls Zn export through CzcD to manage Zn stress, and utilizes a system of arginine deamination never previously linked to metal stress responses in bacteria to survive metal intoxication. We show that these systems are crucial for survival of S. agalactiae in vitro during Zn stress and also enhance virulence during systemic infection in mice. These discoveries establish new molecular mechanisms of resistance to metal intoxication in bacteria; we suggest these mechanisms are likely to operate in other bacteria as a way to sustain microbial survival in conditions of metal stress, including in host environments.

scholarly journals Genetic characterization and diversity of Streptococcus agalactiae isolates with macrolide resistance

2010 ◽  
Vol 59 (7) ◽  
pp. 780-786 ◽  
Author(s):  
Monika Brzychczy-Włoch ◽  
Tomasz Gosiewski ◽  
Małgorzata Bodaszewska ◽  
Wojciech Pabian ◽  
Małgorzata Bulanda ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Macrolide Resistance ◽  
Surface Proteins ◽  
Erythromycin Resistance ◽  
High Genetic Diversity ◽  
Genes Encoding ◽  
Resistant Strains ◽  
Group B

Macrolide resistance in 169 Streptococcus agalactiae [group B streptococcus (GBS)] isolates originating from pregnant carriers was investigated. Using multiplex PCR the presence of genes encoding erythromycin resistance and capsular polysaccharides, as well as surface proteins, was determined. Random amplification of polymorphic DNA (RAPD) and PFGE were used to characterize specific clones among the isolates. In the examined population of women, erythromycin-resistant strains were found in 4.5 % of patients, whereas clindamycin-resistant strains were found in 3 % of patients, which was 16 % of strains resistant to erythromycin and 10 % of strains resistant to clindamycin among GBS isolates, respectively. Among the isolates, the largest percentage was represented by the constitutive macrolide–lincosamide–streptogramin B (cMLSB) phenotype (63 %), then the inductive macrolide–lincosamide–streptogramin B (iMLSB) phenotype (26 %) and the macrolide resistance (M) phenotype (11 %). The ermB gene was indicated in all isolates with the cMLSB phenotype and V serotype, whereas mefA/mefE genes were found in isolates with the M phenotype and Ia serotype. Among resistance isolates, serotype V was predominant (67 %), followed by serotypes II (15 %), Ia (11 %) and III (7 %). The most common surface protein encoding genes were alp3 (70 %), then rib (11 %), epsilon (7.5 %), bca (7.5 %) and alp2 (4 %). A statistically significant relationship between macrolide resistance, serotype V and the alp3 gene was demonstrated. PFGE, in comparison to the RAPD method, gave better genetic discrimination of GBS isolates. A relatively high genetic diversity among investigated strains was shown. In addition, the largest genetic homogeneity was found in serotype V.

An Emerging Infection: Streptococcal Toxic Shock-Like Syndrome Caused By Group B Streptococcus (GBS), Streptococcus Agalactiae

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S140-S140
Author(s):  
F Rajack ◽  
A Afsari ◽  
A M Ramadan ◽  
T J Naab
Keyword(s):  
Soft Tissue ◽  
Necrotizing Fasciitis ◽  
Streptococcus Agalactiae ◽  
Group A Streptococcus ◽  
Multiorgan Failure ◽  
Group B Streptococcus ◽  
Stage Iii ◽  
Streptococcal Toxic Shock Syndrome ◽  
Toxic Shock ◽  
Group B

Abstract Introduction/Objective Streptococcus agalactiae, Group B Streptococcus (GBS), is a major cause of neonatal sepsis and infections in pregnant women. However, incidence of invasive GBS infections has more than doubled in the last two decades with highest risk in adults 65 years or older. Other risk factors are diabetes, malignancy, and immunocompromised state. Bacteremia and skin soft tissue infections are the most common invasive infections in nonpregnant adults. Rarely GBS infection has a fulminating pyrogenic exotoxin-mediated course characterized by acute onset, multiorgan failure, shock, and sometimes death, referred to as toxic shock-like syndrome. Methods A 77-year-old hypertensive female with uncontrolled type 2 diabetes mellitus and a history of bilateral foot ulcers presented to the hospital in probable septic shock. Clinical diagnosis of necrotizing fasciitis was made and she underwent bilateral lower limb amputations. Results Grossly soft tissue appeared gray. Microscopically fascia was necrotic without neutrophils present and Gram stain revealed sheets of Gram positive cocci. These findings reflected histopathologic Stage III necrotizing fasciitis, which is associated with 47% mortality. Autopsy showed a similar histology of Stage III necrotizing fasciitis involving the surgical stump. Erythema and desquamation of the upper limbs bilaterally and multi-organ failure met the clinical picture of Streptococcal Toxic Shock Syndrome (STSS) and fulfilled the criteria for TSS due to Group A Streptococcus (GAS), defined by The Working Group on Severe Streptococcal Infections. Conclusion Group B Streptococcal Toxic Shock-Like Syndrome may have a similar outcome to STSS caused by GAS and other pathogens and, in limited studies, mortality has been 30% or greater.

scholarly journals Induction of experimental allergic arthritis with outer surface proteins ofborrelia burgdorferi

1994 ◽  
Vol 37 (7) ◽  
pp. 1070-1077 ◽  
Author(s):  
Klaus B. Gondolf ◽  
Michael Mihatsch ◽  
Enrico Curschellas ◽  
John J. Dunn ◽  
Steven R. Batsford
Keyword(s):  
Outer Surface ◽  
Surface Proteins ◽  
Outer Surface Proteins ◽  
Experimental Allergic

Group B Streptococcal and Pneumococcal Sepsis in Newborn Infants: The Role of Pneumococcal Antibody

PEDIATRICS ◽  
1978 ◽  
Vol 62 (4) ◽  
pp. 620-621
Author(s):  
Gerald W. Fischer ◽  
James W. Bass ◽  
George H. Lowell ◽  
Martin H. Crumrine
Keyword(s):  
Streptococcus Pneumoniae ◽  
Hydrochloric Acid ◽  
Group B Streptococcus ◽  
Newborn Infants ◽  
Polysaccharide Antigen ◽  
Type Iii ◽  
Pneumococcal Sepsis ◽  
Group B

The article by Bortolussi et al. on pneumococcal septicemia and meningitis in the neonat (Pediatrics 60:352, September 1977) was of great interest to us, since we have been analyzing the effect of antibody directed against Streptococcus pneumoniae on group B Streptococcus type III. We have recently shown (unpublished data) that antibody directed against S. pneumoniae type 14 precipitates the hot hydrochloric acid-extracted polysaccharide antigen of group B Streptococcus type III. Further studies have shown that this antibody is opsonic for group B Streptococcus type III in an in vitro bactericidal assay and protective in a suckling rat model of group B Streptococcus type III sepsis.1

scholarly journals Prevalence and Serotype Determination of Streptococcus agalactiae Isolated From Non-Pregnant Women in Tehran, Iran

2020 ◽  
Author(s):  
Leila Goudarzi ◽  
Mohammad Bagher Khalili ◽  
Mahmood Vakili ◽  
Maryam Sadeh
Keyword(s):  
Pregnant Women ◽  
Streptococcus Agalactiae ◽  
Group B Streptococcus ◽  
Cross Sectional Study ◽  
Chi Square ◽  
Cross Sectional ◽  
Specific Pcr ◽  
Pcr Method ◽  
Group B ◽  
Tehran Area

Consequence of Streptococcus agalactiae, Group B Streptococcus (GBS) relating infant’s diseases are well documented. Although many women carry this bacterium in their vagina, they may transfer to their infant during delivery and may result in different neonatal invasive diseases. The aim of this study was to determine the prevalence of GBS and serotyping the isolated species among un-selective non-pregnant women who attended two gynecology clinics in Tehran. In this cross-sectional study, a total of 560 vaginal samples collected from non-pregnant women. Following inoculation of the specimen on Blood Agar, the standard technology was applied for the final identification of GBS. Detected GBS species were further confirmed using specific PCR directed on dlts gene. Capsular serotyping was done by using the multiplex PCR method. The chi-square method was used for statistical analysis. Fifty (8.9%) out of 560 non-pregnant women were carriers of GBS. The most common types were III (36%), followed by type II (32%), Ia (26%), and Ib (6%), respectively. Results represent that the prevalence rate of GBS in non-pregnant women was reliable and similar to what obtained from pregnant women. In addition, the serotype III was found the most dominant types, as well as other investigations in the Tehran area. Therefore, vaccine designation based on type III is recommended.

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