scholarly journals EndoS and SpeB from Streptococcus pyogenes Inhibit Immunoglobulin-Mediated Opsonophagocytosis

2002 ◽  
Vol 70 (12) ◽  
pp. 6646-6651 ◽  
Author(s):  
Mattias Collin ◽  
Mikael D. Svensson ◽  
Anders G. Sjöholm ◽  
Jens C. Jensenius ◽  
Ulf Sjöbring ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Ex Vivo ◽  
Adaptive Immune System ◽  
Invasive Disease ◽  
Classical Pathway ◽  
Bacterial Survival ◽  
Upper Respiratory Tract ◽  
Human Pathogen ◽  
Adaptive Immune ◽  
Upper Respiratory

ABSTRACT The human pathogen Streptococcus pyogenes primarily infects the upper respiratory tract and skin, but occasionally it disseminates and causes severe invasive disease with high mortality. This study revealed that the activity of extracellular EndoS, which hydrolyzes the functionally important N-linked oligosaccharides on opsonizing immunoglobulin G (IgG), contributes to increased survival of S. pyogenes in human blood ex vivo. The inability to kill the bacteria is due to reduced binding of IgG to Fc receptors and impaired classical pathway-mediated activation of complement. In addition, the activity of extracellular SpeB, which cleaves IgG into Fc and Fab fragments, also increases bacterial survival. This suggests that S. pyogenes expresses two enzymes, EndoS and SpeB, which modulate IgG by different mechanisms in order to evade the adaptive immune system.

scholarly journals Effects of helium and air inhalation on the innate and early adaptive immune system in healthy volunteers ex vivo

2012 ◽  
Vol 10 (1) ◽  
pp. 201 ◽  
Author(s):  
Gezina TML Oei ◽  
Kirsten F Smit ◽  
Djai vd Vondervoort ◽  
Daniel Brevoord ◽  
Arjan Hoogendijk ◽  
...  
Keyword(s):  
Immune System ◽  
Healthy Volunteers ◽  
Ex Vivo ◽  
Adaptive Immune System ◽  
Adaptive Immune

scholarly journals Silent Mastoiditis Associated with Pneumococcal Meningitis

2021 ◽  
Vol 27 (2) ◽  
pp. 1-6
Author(s):  
Ashikin Mohd Nordin ◽  
Jean Jun Ong ◽  
Juriza Ismail ◽  
Norazlin Kamal Nor ◽  
Sau Wei Wong ◽  
...  
Keyword(s):  
Brain Imaging ◽  
Pneumococcal Meningitis ◽  
Wide Spectrum ◽  
Clinical Signs ◽  
Invasive Disease ◽  
Upper Respiratory Tract ◽  
Slow Recovery ◽  
Acute Mastoiditis ◽  
Focus Of Infection ◽  
Upper Respiratory

Streptococcus pneumoniae (S pneumoniae) can cause a wide spectrum of diseases which includes upper respiratory tract infection as well as more severe invasive disease such as meningitis. Meningitis may be caused by invasion of the organism through the blood brain barrier, either via haematological spread or from an adjacent focus of infection such as the ears. We describe two infants with pneumococcal meningitis and silent mastoiditis. They both presented with a classical history to suggest meningitis with no apparent focus of infection. A brain imaging was done in the first infant to look for the underlying cause of his focal seizure and in the second infant, to assess for complications of meningitis, as he had a slow recovery. While they did not have any clinical signs to point towards the diagnosis, they were both diagnosed to have acute mastoiditis from brain imaging. We would like to highlight the importance of brain imaging in excluding silent mastoiditis in infants with meningitis, particularly in those whose clinical course appears atypical.

scholarly journals The Upper Respiratory Tract of Felids Is Highly Susceptible to SARS-CoV-2 Infection

2021 ◽  
Vol 22 (19) ◽  
pp. 10636
Author(s):  
Nadine Krüger ◽  
Cheila Rocha ◽  
Sandra Runft ◽  
Johannes Krüger ◽  
Iris Färber ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Cell Cultures ◽  
Ex Vivo ◽  
Virus Transmission ◽  
Upper Respiratory Tract ◽  
Pathological Changes ◽  
Domestic Cats ◽  
Changes Detection ◽  
Upper Respiratory ◽  
Air Liquid Interface

Natural or experimental infection of domestic cats and virus transmission from humans to captive predatory cats suggest that felids are highly susceptible to SARS-CoV-2 infection. However, it is unclear which cells and compartments of the respiratory tract are infected. To address this question, primary cell cultures derived from the nose, trachea, and lungs of cat and lion were inoculated with SARS-CoV-2. Strong viral replication was observed for nasal mucosa explants and tracheal air–liquid interface cultures, whereas replication in lung slices was less efficient. Infection was mainly restricted to epithelial cells and did not cause major pathological changes. Detection of high ACE2 levels in the nose and trachea but not lung further suggests that susceptibility of feline tissues to SARS-CoV-2 correlates with ACE2 expression. Collectively, this study demonstrates that SARS-CoV-2 can efficiently replicate in the feline upper respiratory tract ex vivo and thus highlights the risk of SARS-CoV-2 spillover from humans to felids.

scholarly journals The basic keratin 10-binding domain of the virulence-associated pneumococcal serine-rich protein PsrP adopts a novel MSCRAMM fold

Open Biology ◽  
2014 ◽  
Vol 4 (1) ◽  
pp. 130090 ◽  
Author(s):  
Tim Schulte ◽  
Jonas Löfling ◽  
Cecilia Mikaelsson ◽  
Alexey Kikhney ◽  
Karina Hentrich ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Invasive Disease ◽  
Binding Domain ◽  
Upper Respiratory Tract ◽  
Binding Region ◽  
Sequence Identity ◽  
Novel Variant ◽  
Upper Respiratory ◽  
Β Sheet ◽  
Specific Virulence

Streptococcus pneumoniae is a major human pathogen, and a leading cause of disease and death worldwide. Pneumococcal invasive disease is triggered by initial asymptomatic colonization of the human upper respiratory tract. The pneumococcal serine-rich repeat protein (PsrP) is a lung-specific virulence factor whose functional binding region (BR) binds to keratin-10 (KRT10) and promotes pneumococcal biofilm formation through self-oligomerization. We present the crystal structure of the KRT10-binding domain of PsrP (BR 187–385 ) determined to 2.0 Å resolution. BR 187–385 adopts a novel variant of the DEv-IgG fold, typical for microbial surface components recognizing adhesive matrix molecules adhesins, despite very low sequence identity. An extended β-sheet on one side of the compressed, two-sided barrel presents a basic groove that possibly binds to the acidic helical rod domain of KRT10. Our study also demonstrates the importance of the other side of the barrel, formed by extensive well-ordered loops and stabilized by short β-strands, for interaction with KRT10.

Better together: Alveolar macrophage and memory T cell cosignaling in ex vivo human lungs

2021 ◽  
Vol 13 (578) ◽  
pp. eabg5637
Author(s):  
Steven P. Keller
Keyword(s):  
Ex Vivo ◽  
Adaptive Immune System ◽  
Lung Perfusion ◽  
Ex Vivo Lung Perfusion ◽  
Memory T Cell ◽  
Adaptive Immune ◽  
Human Lungs ◽  
Insight Into ◽  
Pathogen Exposure ◽  
Lung Response

Ex vivo lung perfusion enables assessment of the resident adaptive immune system and provides insight into the lung response to pathogen exposure.

scholarly journals Susceptibility of common bacterial respiratory pathogens to antimicrobial agents in outpatients from south Backa District

2014 ◽  
Vol 67 (3-4) ◽  
pp. 71-77 ◽  
Author(s):  
Olga Horvat ◽  
Mira Mihajlovic-Ukropina ◽  
Vesna Mijatovic ◽  
Ana Sabo
Keyword(s):  
Respiratory Tract ◽  
Haemophilus Influenzae ◽  
Streptococcus Pyogenes ◽  
Antimicrobial Agents ◽  
National Guideline ◽  
Diffusion Method ◽  
Respiratory Pathogens ◽  
Upper Respiratory Tract ◽  
Upper Respiratory ◽  
Susceptibility Tests

Introduction. Acute infections of the upper respiratory tract are the most common reasons why patients visit general practitioners. Overuse of antibiotics in treatment of these conditions is extremely common practice although these infections are most frequently caused by viruses. The aim of this study was to determine the distribution and susceptibility of common pathogens to antimicrobial agents that cause infections of the upper respiratory tract in outpatients and to determine whether the results obtained from the examined sample were in accordance with the recommendations of the current National Guideline. Material and Methods. .The study included 945 strains isolated from the throat and nasal swabs from January 1st to March 31st, 2008, as well as from 330 strains isolated from January 1st to March 31st, 2013 in South Backa District, Serbia. Susceptibility tests were performed by the standard disc diffusion method and according to the criteria recommended by the Clinical and Laboratory Standards Institute. Results. The most commonly isolated strains were Streptococcus pyogenes, Staphylococcus aureus, Streptococcus pneumoniae, Branchamella catarrhalis, and Haemophilus influenzae. Susceptibility of Streptococcus pyogenes, Branchamella catarrhalis and Haemophilus influenzae to examined antibiotics did not substantially change over the two study periods. None of the isolates of Staphylococcus aures demonstrated resistance to methicillin in 2008, while the percentage of resistant strains was 5.93% in 2013. Susceptibility rates of Staphylococcus pneumoniae isolates to erythromycin and clindamycin were lower in 2013 than in 2008. Conclusion. The investigation results follow the recommendations of the National Guideline for the usage of natural penicillin in the treatment of tonsillopharyngitis. Amoxicillin/clavulanic acid is recommended for the treatment of rhinosinusitis, and second generation cephalosporins are the second choice.

Severe Lactational Mastitis With Complicated Wound Infection Caused by Streptococcus pyogenes

2020 ◽  
pp. 089033442096514
Author(s):  
Josefine Theresia Maier ◽  
Julia Daut ◽  
Elisabeth Schalinski ◽  
Toni Fischer-Medert ◽  
Lars Hellmeyer
Keyword(s):  
Wound Healing ◽  
Streptococcus Pyogenes ◽  
Acute Otitis Media ◽  
Interdisciplinary Approach ◽  
Invasive Disease ◽  
Left Breast ◽  
Upper Respiratory Tract ◽  
Wound Healing Problems ◽  
Lactating Breast ◽  
Skin Erosion

Introduction Puerperal mastitis, a complication occurring during the breastfeeding period, is often caused by Staphylococcus aureus. Here we report on severe streptococcal mastitis in a lactating breast, with subsequent invasive disease and wound healing problems. Main issue The 41-year-old woman (G2, P2) presented at 2 weeks postpartum to our hospital with painful swelling and reddening of the left breast, in addition to fever and malaise, and complained about a nipple fissure on the left breast. Previously, her 4-year-old son was treated for an acute otitis media and her husband experienced flu-like symptoms. Management Due to the severity of the symptoms, Clindamycin antibiotic treatment was initiated intravenously. Streptococcus pyogenes was isolated in the milk. This strain is commonly known to cause infections of the upper respiratory tract, skin, and soft tissue, but rarely mastitis. Furthermore, the participant developed invasive disease with abscess formation and skin erosion with a milk fistula. Special dressing was applied to promote wound healing. The participant continued breastfeeding well into the child’s 2nd year of life. Conclusion This rare form of complicated mastitis with invasive disease caused by Streptococcus pyogenes called for an interdisciplinary approach. We want to draw attention to other pathogens causing mastitis and to alert health care workers to promote hygiene in lactating women to prevent transmission.

scholarly journals Increased Chain Length Promotes Pneumococcal Adherence and Colonization

2012 ◽  
Vol 80 (10) ◽  
pp. 3454-3459 ◽  
Author(s):  
Jesse L. Rodriguez ◽  
Ankur B. Dalia ◽  
Jeffrey N. Weiser
Keyword(s):  
Parental Strain ◽  
A549 Cells ◽  
Invasive Disease ◽  
Upper Respiratory Tract ◽  
Epithelial Surface ◽  
Content Type ◽  
Morphological Heterogeneity ◽  
Upper Respiratory

ABSTRACTStreptococcus pneumoniaeis a mucosal pathogen that grows in chains of variable lengths. Short-chain forms are less likely to activate complement, and as a consequence they evade opsonophagocytic clearance more effectively during invasive disease. When grown in human nasal airway surface fluid, pneumococci exhibited both short- and long-chain forms. Here, we determined whether longer chains provide an advantage during colonization when the organism is attached to the epithelial surface. Chain-forming mutants and the parental strain grown under conditions to promote chain formation showed increased adherence to human epithelial cells (A549 cells)in vitro. Additionally, adherence to A549 cells selected for longer chains within the wild-type strain.In vivoin a murine model of colonization, chain-forming mutants outcompeted the parental strain. Together, our results demonstrate that morphological heterogeneity in the pneumococcus may promote colonization of the upper respiratory tract by enhancing the ability of the organism to bind to the epithelial surface.

scholarly journals IdentifyingStreptococcus pneumoniaegenes associated with invasive disease using pangenome-based whole genome sequence typing

2018 ◽  
Author(s):  
Uri Obolski ◽  
Andrea Gori ◽  
José Lourenço ◽  
Craig Thompson ◽  
Robin Thompson ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Pneumococcal Disease ◽  
Learning Algorithm ◽  
Invasive Disease ◽  
Whole Genome Sequence ◽  
Data Sets ◽  
Whole Genome ◽  
Upper Respiratory Tract ◽  
Pneumococcal Carriage ◽  
Upper Respiratory

AbstractStreptococcus pneumoniaeis a normal commensal of the upper respiratory tract but can also invade the bloodstream or CSF (cerebrospinal fluid), causing invasive pneumococcal disease (IPD). In this study, we attempt to identify genes associated with IPD by applying a random forest machine-learning algorithm to whole genome sequence (WGS) data. We find 43 genes consistently associated with IPD across three geographically distinct WGS data sets of pneumococcal carriage isolates. Of these genes, 23 genes have previously shown to be directly relevant to IPD, while the other 18 are uncharacterized.

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