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Cell Feb 2024Streptococcus anginosus (S. anginosus) was enriched in the gastric mucosa of patients with gastric cancer (GC). Here, we show that S. anginosus colonized the mouse...
Streptococcus anginosus (S. anginosus) was enriched in the gastric mucosa of patients with gastric cancer (GC). Here, we show that S. anginosus colonized the mouse stomach and induced acute gastritis. S. anginosus infection spontaneously induced progressive chronic gastritis, parietal cell atrophy, mucinous metaplasia, and dysplasia in conventional mice, and the findings were confirmed in germ-free mice. In addition, S. anginosus accelerated GC progression in carcinogen-induced gastric tumorigenesis and YTN16 GC cell allografts. Consistently, S. anginosus disrupted gastric barrier function, promoted cell proliferation, and inhibited apoptosis. Mechanistically, we identified an S. anginosus surface protein, TMPC, that interacts with Annexin A2 (ANXA2) receptor on gastric epithelial cells. Interaction of TMPC with ANXA2 mediated attachment and colonization of S. anginosus and induced mitogen-activated protein kinase (MAPK) activation. ANXA2 knockout abrogated the induction of MAPK by S. anginosus. Thus, this study reveals S. anginosus as a pathogen that promotes gastric tumorigenesis via direct interactions with gastric epithelial cells in the TMPC-ANXA2-MAPK axis.
Topics: Animals; Humans; Mice; Atrophy; Carcinogenesis; Cell Transformation, Neoplastic; Gastric Mucosa; Gastritis; Inflammation; Mitogen-Activated Protein Kinases; Stomach Neoplasms; Streptococcus anginosus; Streptococcal Infections
PubMed: 38295787
DOI: 10.1016/j.cell.2024.01.004 -
Frontiers in Microbiology 2022Three distinct streptococcal species: , and , belonging to the group (SAG), also known as group, have been attracting clinicians and microbiologists, not only as oral... (Review)
Review
Three distinct streptococcal species: , and , belonging to the group (SAG), also known as group, have been attracting clinicians and microbiologists, not only as oral commensals but also as opportunistic pathogens. For years they have been simply classified as so called viridans streptococci, and distinct species were not associated with particular clinical manifestations. Therefore, description of SAG members are clearly underrepresented in the literature, compared to other medically relevant streptococci. However, the increasing number of reports of life-threatening infections caused by SAG indicates their emerging pathogenicity. The improved clinical data generated with the application of modern molecular diagnostic techniques allow for precise identification of individual species belonging to SAG. This review summarizes clinical reports on SAG infections and systematizes data on the occurrence of individual species at the site of infection. We also discuss the issue of proper microbiological diagnostics, which is crucial for further clinical treatment.
PubMed: 35898914
DOI: 10.3389/fmicb.2022.956677 -
Clinical Microbiology and Infection :... Sep 2017A brain abscess is a focal infection of the brain that begins as a localized area of cerebritis. In immunocompetent patients, bacteria are responsible for >95% of brain... (Review)
Review
BACKGROUND
A brain abscess is a focal infection of the brain that begins as a localized area of cerebritis. In immunocompetent patients, bacteria are responsible for >95% of brain abscesses, and enter the brain either through contiguous spread following otitis, sinusitis, neurosurgery, or cranial trauma, or through haematogenous dissemination.
AIMS
To identify recent advances in the field.
SOURCES
We searched Medline and Embase for articles published during years 2012-2016, with the keywords 'brain' and 'abscess'.
CONTENT
The triad of headache, fever and focal neurological deficit is complete in ∼20% of patients on admission. Brain imaging with contrast-preferentially magnetic resonance imaging-is the reference standard for diagnosis, and should be followed by stereotactic aspiration of at least one lesion, before the start of any antimicrobials. Efforts should be made for optimal management of brain abscess samples, for reliable microbiological documentation. Empirical treatment should cover oral streptococci (including milleri group), methicillin-susceptible staphylococci, anaerobes and Enterobacteriaceae. As brain abscesses are frequently polymicrobial, de-escalation based on microbiological results is safe only when aspiration samples have been processed optimally, or when primary diagnosis is endocarditis. Otherwise, many experts advocate for anaerobes coverage even with no documentation, given the sub-optimal sensitivity of current techniques. A 6-week combination of third-generation cephalosporin and metronidazole will cure most cases of community-acquired brain abscess in immunocompetent patients.
IMPLICATIONS
Significant advances in brain imaging, minimally invasive neurosurgery, molecular biology and antibacterial agents have dramatically improved the prognosis of brain abscess in immunocompetent patients over the last decades.
Topics: Anti-Infective Agents; Brain Abscess; Drainage; Humans; Neurosurgical Procedures
PubMed: 28501669
DOI: 10.1016/j.cmi.2017.05.004 -
The Neurohospitalist Jan 2018
Review
PubMed: 29276565
DOI: 10.1177/1941874417700773 -
Frontiers in Microbiology 2022together with and constitute the group (SAG), until recently considered to be benign commensals of the human mucosa isolated predominantly from oral cavity, but also... (Review)
Review
together with and constitute the group (SAG), until recently considered to be benign commensals of the human mucosa isolated predominantly from oral cavity, but also from upper respiratory, intestinal, and urogenital tracts. For years the virulence potential of SAG was underestimated, mainly due to complications in correct species identification and their assignment to the physiological microbiota. Still, SAG representatives have been associated with purulent infections at oral and non-oral sites resulting in abscesses formation and empyema. Also, life threatening blood infections caused by SAG have been reported. However, the understanding of SAG as potential pathogen is only fragmentary, albeit certain aspects of SAG infection seem sufficiently well described to deserve a systematic overview. In this review we summarize the current state of knowledge of the pathogenicity factors and their mechanisms of action.
PubMed: 36386673
DOI: 10.3389/fmicb.2022.1025136 -
Clinical Microbiology Reviews Jan 1988"Streptococcus milleri" is an unofficial name that has been applied to a group of streptococci which, although basically similar, show various hemolytic, serological,... (Review)
Review
"Streptococcus milleri" is an unofficial name that has been applied to a group of streptococci which, although basically similar, show various hemolytic, serological, and physiological characteristics. The species name Streptococcus anginosus has recently been recognized as the approved name for these organisms. Streptococci known as "S. milleri" have been implicated as etiologic agents in a variety of serious purulent infections, but because of their heterogeneous characteristics, these organisms may be unrecognized or misidentified by clinical laboratorians. This review describes the bacteriological aspects of organisms known as "S. milleri," their clinical significance, and the problems encountered with their identification in the clinical laboratory.
Topics: Humans; Streptococcal Infections; Streptococcus
PubMed: 3060239
DOI: 10.1128/CMR.1.1.102 -
Clinical Infectious Diseases : An... Nov 2023Many community-acquired pleural infections are caused by facultative and anaerobic bacteria from the human oral microbiota. The epidemiology, clinical characteristics,...
BACKGROUND
Many community-acquired pleural infections are caused by facultative and anaerobic bacteria from the human oral microbiota. The epidemiology, clinical characteristics, pathogenesis, and etiology of such infections are little studied. The aim of the present prospective multicenter cohort study was to provide a thorough microbiological and clinical characterization of such oral-type pleural infections and to improve our understanding of the underlying etiology and associated risk factors.
METHODS
Over a 2-year period, we included 77 patients with community-acquired pleural infection, whereof 63 (82%) represented oral-type pleural infections. Clinical and anamnestic data were systematically collected, and patients were offered a dental assessment by an oral surgeon. Microbial characterizations were done using next-generation sequencing. Obtained bacterial profiles were compared with microbiology data from previous investigations on odontogenic infections, bacteremia after extraction of infected teeth, and community-acquired brain abscesses.
RESULTS
From the oral-type pleural infections, we made 267 bacterial identifications representing 89 different species. Streptococcus intermedius and/or Fusobacterium nucleatum were identified as a dominant component in all infections. We found a high prevalence of dental infections among patients with oral-type pleural infection and demonstrate substantial similarities between the microbiology of such pleural infections and that of odontogenic infections, odontogenic bacteremia, and community-acquired brain abscesses.
CONCLUSIONS
Oral-type pleural infection is the most common type of community-acquired pleural infection. Current evidence supports hematogenous seeding of bacteria from a dental focus as the most important underlying etiology. Streptococcus intermedius and Fusobacterium nucleatum most likely represent key pathogens necessary for establishing the infection.
Topics: Humans; Fusobacterium nucleatum; Streptococcus intermedius; Cohort Studies; Prospective Studies; Empyema, Pleural; Bacteria; Communicable Diseases; Brain Abscess; Bacteremia
PubMed: 37348872
DOI: 10.1093/cid/ciad378 -
Archives of Disease in Childhood Dec 1992Over a 17 year period, 1975-91, 10 children were managed who had sinusitis-induced subdural or extradural empyema. Their ages ranged from 6 to 14 years, with a mean of...
Over a 17 year period, 1975-91, 10 children were managed who had sinusitis-induced subdural or extradural empyema. Their ages ranged from 6 to 14 years, with a mean of 11 years. All presented with worsening headaches, fever, vomiting, all had neurological abnormalities, and all had symptoms or signs suggestive of sinusitis. Initial computed tomography gave normal results in five cases and the empyema was diagnosed on the second or third scan. All patients had symptoms for at least one to two weeks before the diagnosis was made. Streptococcus milleri was the organism most frequently implicated. Medical treatment was started in all cases on admission, but all required surgical intervention before resolution.
Topics: Adolescent; Brain; Child; Empyema, Subdural; Female; Humans; Male; Sinusitis; Streptococcus; Time Factors; Tomography, X-Ray Computed
PubMed: 1362638
DOI: 10.1136/adc.67.12.1478 -
Tidsskrift For Den Norske Laegeforening... Aug 2013
Topics: Empyema, Subdural; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Streptococcal Infections; Streptococcus intermedius
PubMed: 23970275
DOI: 10.4045/tidsskr.13.0164