scholarly journals Streptococcus pneumoniae, S. pyogenes, and S. agalactiae membrane phospholipid remodeling in response to human serum

2021 ◽  
Author(s):  
Luke. R. Joyce ◽  
Ziqiang Guan ◽  
Kelli L. Palmer
Keyword(s):  
Streptococcus Pneumoniae ◽  
Human Serum ◽  
Cellular Membrane ◽  
Defined Medium ◽  
Ionization Mass ◽  
Streptococcal Species ◽  
Group A ◽  
Phase Liquid ◽  
Etiological Agents ◽  
Group B

AbstractStreptococcus pneumoniae, S. pyogenes (Group A Streptococcus; GAS), and S. agalactiae (Group B Streptococcus; GBS) are major etiological agents of diseases in humans. The cellular membrane, a crucial site in host-pathogen interactions, is poorly characterized in streptococci. Moreover, little is known about whether or how environmental conditions influence their lipid compositions. Using normal phase liquid chromatography coupled with electrospray ionization mass spectrometry, we characterized the phospholipids and glycolipids of S. pneumoniae, GAS, and GBS in routine undefined laboratory medium, streptococcal defined medium, and, in order to mimic the host environment, defined medium supplemented with human serum. In human serum-supplemented medium, all three streptococcal species synthesize phosphatidylcholine (PC), a zwitterionic phospholipid commonly found in eukaryotes but relatively rare in bacteria. We previously reported that S. pneumoniae utilizes the glycerophosphocholine (GPC) biosynthetic pathway to synthesize PC. Through substrate tracing experiments, we confirm that GAS and GBS scavenge lysoPC, a major metabolite in human serum, thereby using an abbreviated GPC pathway for PC biosynthesis. Furthermore, we found that plasmanyl-PC is uniquely present in the GBS membrane during growth with human serum, suggesting GBS possesses unusual membrane biochemical or biophysical properties. In summary, we report cellular lipid remodeling by the major pathogenic streptococci in response to metabolites present in human serum.

scholarly journals Streptococcus pneumoniae, S. pyogenes and S. agalactiae membrane phospholipid remodelling in response to human serum

Microbiology ◽  
2021 ◽  
Vol 167 (5) ◽  
Author(s):  
Luke R. Joyce ◽  
Ziqiang Guan ◽  
Kelli L. Palmer
Keyword(s):  
Streptococcus Pneumoniae ◽  
Human Serum ◽  
Type Species ◽  
Cellular Membrane ◽  
Defined Medium ◽  
Content Type ◽  
Link Type ◽  
Streptococcal Species ◽  
Group A ◽  
Group B

Streptococcus pneumoniae , S. pyogenes (Group A Streptococcus ; GAS) and S. agalactiae (Group B Streptococcus ; GBS) are major aetiological agents of diseases in humans. The cellular membrane, a crucial site in host–pathogen interactions, is poorly characterized in streptococci. Moreover, little is known about whether or how environmental conditions influence their lipid compositions. Using normal phase liquid chromatography coupled with electrospray ionization MS, we characterized the phospholipids and glycolipids of S. pneumoniae , GAS and GBS in routine undefined laboratory medium, streptococcal defined medium and, in order to mimic the host environment, defined medium supplemented with human serum. In human serum-supplemented medium, all three streptococcal species synthesize phosphatidylcholine (PC), a zwitterionic phospholipid commonly found in eukaryotes but relatively rare in bacteria. We previously reported that S. pneumoniae utilizes the glycerophosphocholine (GPC) biosynthetic pathway to synthesize PC. Through substrate tracing experiments, we confirm that GAS and GBS scavenge lysoPC, a major metabolite in human serum, thereby using an abbreviated GPC pathway for PC biosynthesis. Furthermore, we found that plasmanyl-PC is uniquely present in the GBS membrane during growth with human serum, suggesting GBS possesses unusual membrane biochemical or biophysical properties. In summary, we report cellular lipid remodelling by the major pathogenic streptococci in response to metabolites present in human serum.

scholarly journals Interspecies Communication among Commensal and Pathogenic Streptococci

mBio ◽  
2013 ◽  
Vol 4 (4) ◽  
Author(s):  
Laura C. Cook ◽  
Breah LaSarre ◽  
Michael J. Federle
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Human Pathogens ◽  
Streptococcus Dysgalactiae ◽  
Interspecies Communication ◽  
Content Type ◽  
Streptococcal Species ◽  
Group A ◽  
Group B ◽  
Regulated Gene Expression

ABSTRACTQuorum sensing (QS) regulates diverse and coordinated behaviors in bacteria, including the production of virulence factors, biofilm formation, sporulation, and competence development. It is now established that some streptococci utilize Rgg-type proteins in concert with short hydrophobic peptides (SHPs) to mediate QS, and sequence analysis reveals that several streptococcal species contain highly homologous Rgg/SHP pairs. In group A streptococcus (GAS), two SHPs (SHP2 and SHP3 [SHP2/3]) were previously identified to be important in GAS biofilm formation. SHP2/3 are detected by two antagonistic regulators, Rgg2 and Rgg3, which control expression of theshpgenes. In group B streptococcus (GBS), RovS is a known virulence gene regulator and ortholog of Rgg2, whereas no apparent Rgg3 homolog exists. Adjacent torovSis a gene (shp1520) encoding a peptide nearly identical to SHP2. Using isogenic mutant strains and transcriptional reporters, we confirmed that RovS/SHP1520 comprise a QS circuit in GBS. More important, we performed experiments demonstrating that production and secretion of SHP1520 by GBS can modulate Rgg2/3-regulated gene expression in GAS intrans; likewise, SHP2/3 production by GAS can stimulate RovS-mediated gene regulation in GBS. An isolate ofStreptococcus dysgalactiaesubsp.equisimilisalso produced a secreted factor capable of simulating the QS circuits of both GAS and GBS, and sequencing confirms the presence of an orthologous Rgg2/SHP2 pair in this species as well. To our knowledge, this is the first documented case of bidirectional signaling between streptococcal species in coculture and suggests a role for orthologous Rgg/SHP systems in interspecies communication between important human pathogens.IMPORTANCEPathogenic streptococci, such as group A (GAS) and group B (GBS) streptococcus, are able to persist in the human body without causing disease but become pathogenic under certain conditions that are not fully characterized. Environmental cues and interspecies signaling between members of the human flora likely play an important role in the transition to a disease state. Since quorum-sensing (QS) peptides have been consistently shown to regulate virulence factor production in pathogenic species, the ability of bacteria to signal via these peptides may prove to be an important link between the carrier and pathogenic states. Here we provide evidence of a bidirectional QS system between GAS, GBS, andStreptococcus dysgalactiaesubsp.equisimilis, demonstrating the possibility of evolved communication systems between human pathogens.

scholarly journals Influence of the cerebrospinal fluid laboratory parameters in the ELISA test for neurocysticercosis using a total cysticerci antigen

2006 ◽  
Vol 64 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Cristiane S. Casanova ◽  
Maria José S.P. Ribeiro ◽  
Reizer R. Gonçalves ◽  
Luiz Cláudio Faria ◽  
José Mauro Peralta ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Neurological Disorders ◽  
Protein Concentration ◽  
Elisa Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Csf Analysis ◽  
Elisa Testing ◽  
Group A ◽  
Etiological Agents ◽  
Group B

To evaluate if the cerebrospinal fluid (CSF) parameters may influence the cysticercosis immunoreactivity response in the CSF. CSF samples of 109 patients were analyzed and classified in three groups, according to the neurological manifestations and the reactivity in antibody-enzyme linked immunosorbent assay (Ab-ELISA) testing in CSF for neurocysticercosis (NC): group A, 18 patients with neurological disorders compatible with NC and reactive Ab-ELISA in CSF for NC; group B, 50 patients with neurological disorders non-compatible with NC and reactive Ab-ELISA for NC; group C, 41 patients with neurological disorders non-compatible with NC and non-reactive Ab-ELISA in CSF for NC. The CSF analysis in group A was compatible with NC. The group B in comparison to the groups A and C presents higher frequency and intensity of hypercytosis, presence of red blood cells in CSF, protein concentration and immunological reactive test for other etiological agents (p<0.05). Based on the present data, we suggest that the inflammatory process and high protein concentration may determine false positive reactions in the Ab-ELISA test for NC in the CSF.

scholarly journals 1625. Risk of Invasive Group A Streptococcus, Group B Streptococcus, and Streptococcus pneumoniae Infection Among Adults Experiencing Homelessness—Anchorage, Alaska, 2002–2015

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S593-S593
Author(s):  
Emily Mosites ◽  
Tammy Zulz ◽  
Dana Bruden ◽  
Leisha Nolen ◽  
Anna Frick ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
General Population ◽  
Group A Streptococcus ◽  
Group B Streptococcus ◽  
Pneumococcal Infection ◽  
Homeless Population ◽  
Invasive Group ◽  
Increased Risk ◽  
Group A ◽  
Group B

Abstract Background People experiencing homelessness (PEH) have an increased risk of infectious disease. However, for many infections, this increased risk has not been clearly quantified. For example, the risk of invasive streptococcal infection has not been established among PEH in the United States. Methods We compared the incidence of detected cases of invasive group A Streptococcus (GAS) infection, group B Streptococcus (GBS) infection, and Streptococcus pneumoniae (pneumococcal) infection among adult PEH to that in the general adult population in Anchorage, Alaska from 2005 through 2015 using data from the CDC Arctic Investigations Program surveillance system, the US census, and the Anchorage Point in Time count (PIT [a yearly census of PEH]). Results During 2005–2015, the PIT counted a mean number of 970 adults (minimum 795, maximum 1486) in Anchorage who were homeless, which accounted for 0.4% of the total population. Compared with the general population, PEH were 53 times as likely to have invasive GAS infection (95% CI 47–61), 7 times as likely to have invasive GBS infection (95% CI 6, 8), and 36 times as likely to have invasive pneumococcal infection (95% CI 33, 40). Of all invasive GAS cases in Anchorage over the time period, 19% occurred within the homeless population, while 3% of invasive GBS cases and 14% of invasive pneumococcal cases were within the homeless population. Additionally, the predominant subtypes of GAS and pneumococcus differed among PEH compared with the general population. Conclusion A disproportionate burden of invasive streptococcal disease in Anchorage was detected among PEH, indicating a need for further focus on this high-risk group. Disclosures All authors: No reported disclosures.

scholarly journals Evidence of Clonal Dissemination of Multidrug-Resistant Streptococcus pneumoniae in Hong Kong

1999 ◽  
Vol 37 (9) ◽  
pp. 2834-2839 ◽  
Author(s):  
Margaret Ip ◽  
Donald J. Lyon ◽  
Raymond W. H. Yung ◽  
Colin Chan ◽  
Augustine F. B. Cheng
Keyword(s):  
Hong Kong ◽  
Streptococcus Pneumoniae ◽  
Restriction Enzymes ◽  
Multidrug Resistant ◽  
Group A ◽  
Rapid Dissemination ◽  
Group B ◽  
Genotypic Characteristics ◽  
The Relationship ◽  
Pattern Group

The relationship between the phenotypic and genotypic characteristics of 105 penicillin-intermediate or -resistantStreptococcus pneumoniae isolates saved during 1994 to 1997 at the Prince of Wales Hospital and Pamela Youde Nethersole Eastern Hospital, Hong Kong, was studied. The pbp genes for penicillin-binding proteins 1a, 2b, and 2x for each isolate were amplified by PCR, and the products were digested with restriction enzymes HinfI and AluI. A combination of the pulsed-field gel electrophoresis (PFGE) profiles, pbpfingerprints, and phenotypic characteristics of capsular types and antibiograms enabled these isolates to be divided into four major groups. Seventy-four percent (78 of 105) of the strains, belonging to serotypes 23F, 19F, and 14, showed indistinguishable pbpfingerprint patterns (group A1, 1-1-1, 1-1-1), with PFGE patterns belonging to group A and its subtypes, suggesting that these strains were closely related. Eighty-three percent (65 of 78) of these isolates were also resistant to tetracycline, erythromycin, chloramphenicol, and trimethoprim. The type 23F isolates were indistinguishable from representative strains of the Spanish 23F clone by these molecular methods, indicating that these strains may be variants of the Spanish 23F clone. Serotype 6B accounted for 19% (20 of 105) of the isolates with reduced penicillin susceptibility and was made up of variants belonging to four different pbp fingerprint groups with the PFGE pattern group B, the predominant group being indistinguishable from that of the Spanish 6B clone. Other PFGE and fingerprint groups were mainly obtained from penicillin-susceptible strains of various serotypes. The results suggest that the rapid emergence of drug-resistant S. pneumoniae in Hong Kong has been due to the rapid dissemination of several successful clones.

An ultrastructural study of sertoli cells in two geographically isolated populations of Aphanius dispar

1992 ◽  
Vol 50 (1) ◽  
pp. 548-549
Author(s):  
Taber A. Ba-Omar ◽  
Philip F. Prentis
Keyword(s):  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Freshwater Teleost ◽  
Isolated Populations ◽  
En Bloc ◽  
The North ◽  
Group A ◽  
Ultrathin Sections ◽  
Group B ◽  
Geographically Isolated

We have recently carried out a study of spermiogenic differentiation in two geographically isolated populations of Aphanius dispar (freshwater teleost), with a view to ascertaining variation at the ultrastructural level. The sampling areas were the Jebel Al Akhdar in the north (Group A) and the Dhofar region (Group B) in the south. Specimens from each group were collected, the testes removed, fixed in Karnovsky solution, post fixed in OsO, en bloc stained with uranyl acetate and then routinely processed to Agar 100 resin, semi and ultrathin sections were prepared for study.

Comparison of one-year prognosis of patients classified as chronic critical lower limb ischaemia according to TASC II or European consensus definition in the COPART cohort

VASA ◽  
2015 ◽  
Vol 44 (3) ◽  
pp. 0220-0228 ◽  
Author(s):  
Marion Vircoulon ◽  
Carine Boulon ◽  
Ileana Desormais ◽  
Philippe Lacroix ◽  
Victor Aboyans ◽  
...  
Keyword(s):  
Medical Treatment ◽  
Critical Limb Ischaemia ◽  
Limb Ischaemia ◽  
Medical Group ◽  
Consensus Definition ◽  
Transcutaneous Oxygen ◽  
European Consensus ◽  
Group A ◽  
One Year ◽  
Group B

Background: We compared one-year amputation and survival rates in patients fulfilling 1991 European consensus critical limb ischaemia (CLI) definition to those clas, sified as CLI by TASC II but not European consensus (EC) definition. Patients and methods: Patients were selected from the COPART cohort of hospitalized patients with peripheral occlusive arterial disease suffering from lower extremity rest pain or ulcer and who completed one-year follow-up. Ankle and toe systolic pressures and transcutaneous oxygen pressure were measured. The patients were classified into two groups: those who could benefit from revascularization and those who could not (medical group). Within these groups, patients were separated into those who had CLI according to the European consensus definition (EC + TASC II: group A if revascularization, group C if medical treatment) and those who had no CLI by the European definition but who had CLI according to the TASC II definition (TASC: group B if revascularization and D if medical treatment). Results: 471 patients were included in the study (236 in the surgical group, 235 in the medical group). There was no difference according to the CLI definition for survival or cardiovascular event-free survival. However, major amputations were more frequent in group A than in group B (25 vs 12 %, p = 0.046) and in group C than in group D (38 vs 20 %, p = 0.004). Conclusions: Major amputation is twice as frequent in patients with CLI according to the historical European consensus definition than in those classified to the TASC II definition but not the EC. Caution is required when comparing results of recent series to historical controls. The TASC II definition of CLI is too wide to compare patients from clinical trials so we suggest separating these patients into two different stages: permanent (TASC II but not EC definition) and critical ischaemia (TASC II and EC definition).

Absorbable suture material in carotid surgery

VASA ◽  
2015 ◽  
Vol 44 (6) ◽  
pp. 451-457 ◽  
Author(s):  
Vincenzo Gasbarro ◽  
Luca Traina ◽  
Francesco Mascoli ◽  
Vincenzo Coscia ◽  
Gianluca Buffone ◽  
...  
Keyword(s):  
Suture Material ◽  
Absorbable Suture ◽  
Paediatric Surgery ◽  
Carotid Surgery ◽  
Suture Materials ◽  
Absorbable Suture Material ◽  
Absorbable Sutures ◽  
Group A ◽  
Group B

Abstract. Background: Absorbable sutures are not generally accepted by most vascular surgeons for the fear of breakage of the suture line and the risk of aneurysmal formation, except in cases of paediatric surgery or in case of infections. Aim of this study is to provide evidence of safety and efficacy of the use of absorbable suture materials in carotid surgery. Patients and methods: In an 11 year period, 1126 patients (659 male [58.5 %], 467 female [41.5 %], median age 72) underwent carotid endarterectomy for carotid stenosis by either conventional with primary closure (cCEA) or eversion (eCEA) techniques. Patients were randomised into two groups according to the type of suture material used. In Group A, absorbable suture material (polyglycolic acid) was used and in Group B non-absorbable suture material (polypropylene) was used. Primary end-point was to compare severe restenosis and aneurysmal formation rates between the two groups of patients. For statistical analysis only cases with a minimum period of follow-up of 12 months were considered. Results: A total of 868 surgical procedures were considered for data analysis. Median follow-up was 6 years (range 1-10 years). The rate of postoperative complications was better for group A for both cCEA and eCEA procedures: 3.5 % and 2.0 % for group A, respectively, and 11.8 % and 12.9 % for group B, respectively. Conclusions: In carotid surgery, the use of absorbable suture material seems to be safe and effective and with a general lower complications rate compared to the use of non-absorbable materials.

Randomized trial of medical compression stockings versus two-layer short-stretch bandaging in the management of venous leg ulcers

Phlebologie ◽  
2009 ◽  
Vol 38 (04) ◽  
pp. 157-163 ◽  
Author(s):  
A. Franek ◽  
L. Brzezinska-Wcislo ◽  
E. Blaszczak ◽  
A. Polak ◽  
J. Taradaj
Keyword(s):  
Drug Therapy ◽  
Randomized Clinical Trials ◽  
Therapy Group ◽  
Long Term Results ◽  
Leg Ulcers ◽  
Compression Stockings ◽  
Venous Leg Ulcers ◽  
Group A ◽  
Group B ◽  
Medical Compression Stockings

SummaryA prospective randomized clinical trial was undertaken to compare a medical compression stockings with two-layer short-stretch bandaging in the management of venous leg ulcers. Study endpoints were number of completely healed wounds and the clinical parameters predicting the outcome. Patients, methods: Eighty patients with venous leg ulcers were included in this study, and ultimately allocated into two comparative groups. Group A consisted of 40 patients (25 women, 15 men). They were treated with the compression stockings (25–32 mmHg) and drug therapy. Group B consisted of 40 patients (22 women, 18 men). They were treated with the short-stretch bandages (30–40 mmHg) and drug therapy, administered identically as in group A. Results: Within two months the 15/40 (37.50%) patients in group A and 5/40 (12.50%) in group B were healed completely (p = 0.01). For patients with isolated superficial reflux, the healing rates at two months were 45.45% (10/22 healed) in group A and 18.18% (4/22 healed) in group B (p = 0.01). For patients with superficial plus deep reflux, the healing rates were 27.77% (5/18 healed) in group A and 5.55% (1/18 healed) in group B (p = 0.002). Comparison of relative change of the total surface area (61.55% in group A vs. 23.66% in group B), length (41.67% in group A vs. 27.99% in group B), width (46.16% in group A vs. 29.33% in group B), and volume (82.03% in group A vs. 40.01% in group B) demonstrated difference (p = 0.002 in all comparisons) in favour of group A. Conclusion: The medical compression stockings are extremely useful therapy in enhancement of venous leg ulcer healing (both for patients with superficial and for patients who had superficial plus deep reflux). Bandages are less effective (especially for patients with superficial plus deep reflux, where the efficiency compared to the stockings of applied compression appeared dramatically low). These findings require confirmation in other randomized clinical trials with long term results.

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