streptococcus mitis+pneumonia

Treatment of pneumococcal infections is limited by antibiotic resistance and exacerbation of disease by bacterial lysis releasing pneumolysin toxin and other inflammatory factors. We identified a previously uncharacterized peptide in the Klebsiella pneumoniae secretome, which enters Streptococcus pneumoniae via its AmiA-AliA/AliB permease. Subsequent downregulation of genes for amino acid biosynthesis and peptide uptake was associated with reduction of pneumococcal growth in defined medium and human cerebrospinal fluid, irregular cell shape, decreased chain length and decreased genetic transformation...

Prolonged exposure to antibiotics at low concentration can promote processes associated with bacterial biofilm formation, virulence and antibiotic resistance. This can be of high relevance in microbial communities like the oral microbiome, where commensals and pathogens share a common habitat and where the total abundance of antibiotic resistance genes surpasses the abundance in the gut. Here, we used an ex vivo model of human oral biofilms to investigate the impact of ampicillin on biofilm viability. The ecological impact on the microbiome and resistome was investigated using shotgun metagenomics...

OBJECTIVES: Recent research has demonstrated that platelet-rich fibrin (PRF) is an appropriate carrier for ampicillin/sulbactam. The aim of the study was to investigate whether PRF is also a suitable bio-carrier for clindamycin (CLI). METHODS: PRF membranes were produced from 36 patients receiving intravenous therapy with CLI (e.g. due to the diagnosis of an osteonecrosis of the jaw or infections). Concentrations of CLI in PRF membranes were measured with liquid chromatography-tandem mass spectrometry, and the antimicrobial effects were investigated in vitro in agar diffusion tests with fresh PRF and PRF stored for 24 h...

BACKGROUND: Dacryocystitis is a common disease in pediatric ophthalmology. Analysis of basic information, flora distribution, and characteristics of information on drug-resistant bacteria in children with dacryocystitis for 6 years, providing evidence for ophthalmologic infection prevention and clinical management strategies. METHODS: A retrospective cohort study was conducted to evaluate the demographics of dacryocystitis in children and microbiological characteristics of secretion cultures, and to analyze the basic information, distribution of pathogenic bacteria, drug resistance, and to plot trendsand distribution pie charts according to the years...

Accurate identification of Mitis group streptococci especially Streptococcus pneumoniae and Streptococcus pseudopneumoniae seems difficult due to the lack of specific and sensitive tests. We performed an approach for the identification of atypical pneumococci in pediatric Tunisian population. In this study, 49 streptococcal isolates that were considered as atypical S. pneumoniae were analyzed by: optochin susceptibility in ambient and 5% CO2 atmosphere, oxgall disk sensitivity, PCR targeting several genes and antimicrobial susceptibility...

Differentiating Streptococcus pneumoniae among nonpneumococcal viridans group streptococci (VGS) is challenging in conventional laboratories. Therefore, we aimed to evaluate the performance of the latest Bruker Biotyper matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system in identifying VGS by comparing the results to those of the specific gene sequencing approach. Clinical isolates were initially identified using the BD Phoenix system to identify Streptococcus species...

UNLABELLED: Rapid and early identification of Streptococcus pneumoniae from positive blood cultures is crucial for the management of patients with bloodstream infections (BSI). Many identification systems in microbiology laboratories have difficulty differentiating S. pneumoniae from other closely related species in the Streptococcus mitis group. To overcome this limitation, we developed a rapid workflow in our laboratory combining direct MALDI-TOF MS identification with the Immulex S...

Bacteria utilize quorum sensing (QS) to coordinate many group behaviors. As such, QS has attracted significant attention as a potential mean to attenuate bacterial infectivity without introducing selective pressure for resistance development. Streptococcus mitis, a human commensal, acts as a genetic diversity reservoir for Streptococcus pneumoniae, a prevalent human pathogen. S. mitis possesses a typical comABCDE competence regulon QS circuitry, however, the competence-stimulating peptide (CSP) responsible for QS activation and the regulatory role of the competence regulon QS circuitry in S...

Sepsis is a life-threatening multiple-organ injury caused by disordered host immune response to microbial infection. However, the correlation between gut microbiota dysbiosis and immune indicators remains unexplored. To address this gap in knowledge, we carried out 16 S rDNA sequencing, analyzed clinical fecal samples from children with sepsis (n = 30) and control children (n = 25), and obtained immune indicators, including T cell subtypes (CD3+ , CD3+ CD4+ , CD3+ CD8+ , and CD4/CD8), NK cells, cytokines (IL-2, IL-4, IL-6, IL-10, TNF-α and IFN-γ), and immunoglobulin indices (IgA, IgE, IgM and IgG)...

BACKGROUND AND OBJECTIVE: Indwelling pleural catheter (IPC) and indwelling peritoneal catheter (IPeC) have established roles in the management of malignant pleural and peritoneal effusions but catheter-related infections remain a major concern. Topical mupirocin prophylaxis has been shown to reduce peritoneal dialysis catheter infections. This study aimed to assess the (i) compatibility of IPC with mupirocin and (ii) feasibility, tolerability and compliance of topical mupirocin prophylaxis in patients with an IPC or IPeC...

BACKGROUND: Increasing studies have shown that the imbalance of the respiratory microbial flora is related to the occurrence of COPD, the severity and frequency of exacerbations and mortality.However, it remains unclear how the sputum microbial flora differs during exacerbations in COPD patients manifesting emphysema phenotype, chronic bronchitis with emphysema phenotype and asthma-COPD overlap phenotype. METHODS: Sputum samples were obtained from 29 COPD patients experiencing acute exacerbations who had not received antibiotics or systemic corticosteroids within the past four weeks...

BACKGROUND: Secondary bacterial infections and pneumonia are major mortality causes of respiratory viruses, and the disruption of the upper respiratory tract (URT) microbiota is a crucial component of this process. However, whether this URT dysbiosis associates with the viral species (in other words, is viral type-specific) is unclear. RESULTS: Here, we recruited 735 outpatients with upper respiratory symptoms, identified the infectious virus types in 349 participants using multiplex RT-PCR, and profiled their upper respiratory microbiome using the 16S ribosomal RNA gene and metagenomic gene sequencing...

BACKGROUND: Due to similar colony morphology among viridans group streptococci (VGS), the differentiation of VGS species remains difficult in routine clinical microbiology. Recently, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has been described as a fast method for identifying various bacteria at species level, and also for the VGS strains. METHODS: A total of 277 VGS isolates were identified with the two MALDI-TOF MS systems (VITEK MS and Bruker Biotyper)...

Streptococcus mitis is a normal member of the human oral microbiota and a leading opportunistic pathogen causing infective endocarditis (IE). Despite the complex interactions between S. mitis and the human host, understanding of S. mitis physiology and its mechanisms of adaptation to host-associated environments is inadequate, especially compared with other IE bacterial pathogens. This study reports the growth-promoting effects of human serum on S. mitis and other pathogenic streptococci, including S. oralis, S...

The oral cavity microbiome comprises benign and pathogenic bacteria, with more than 700 species identified. However, the current literature regarding resident bacterial flora in the oropharyngeal cavities in cleft lip/palate (CLP) patients still needs to be completed. This review aims to evaluate the role of the oral microbiome of cleft patients as an indicator in systemic diseases for which cleft patients might be at higher risk in the short or long term. A literature review was performed in July 2020 using Biomedical Reference Collection Comprehensive, Cumulative Index to Nursing and Allied Health Literature (CINAHL) Complete, Dentistry & Oral Sciences Source via Elton B...

INTRODUCTION: For Streptococcus pneumoniae , β-lactam susceptibility can be predicted from the amino acid sequence of the penicillin-binding proteins PBP1a, PBP2b, and PBP2x. The combination of PBP-subtypes provides a PBP-profile, which correlates to a phenotypic minimal inhibitory concentration (MIC). The non- S. pneumoniae Mitis-group streptococci (MGS) have similar PBPs and exchange pbp -alleles with S. pneumoniae . We studied whether a simple BLAST analysis could be used to predict phenotypic susceptibility in Danish S...

Empyema is often caused by Streptococcus anginous species, followed by Streptococcus pneumoniae . The organism Streptococcus gordonii belongs to the Streptococcus mitis group, which rarely causes empyema. We report the case of a 59-year-old man who presented with exertional dyspnea and chest pain on the right side. The image obtained showed effusion on the right side. Streptococcus gordonii was recovered from purulent pleural effusion culture. The patient underwent video-assisted thoracoscopic surgery with decortication, pneumolysis and received antibiotics for 13 days...

Bacteriophage-derived endolysins and bacterial autolysins (hereinafter lysins) represent a completely new class of efficient antibacterials. They prevent the development of bacterial resistance and help protect commensal microbiota, producing cell wall lysis. Here we have investigated whether the acquisition of enzymatic active domains (EADs) and cell wall binding domains (CWBDs) of balancing efficiencies could be a way of tuning natural lysin activity. The concept was applied to produce a chimeric lysin of superior antibacterial capacity using the endolysin Skl and the major pneumococcal autolysin LytA...

Members of the mitis group streptococci are the most abundant inhabitants of the oral cavity and dental plaque. Influenza A virus (IAV), the causative agent of influenza, infects the upper respiratory tract, and co-infection with Streptococcus pneumoniae is a major cause of morbidity during influenza epidemics. S. pneumoniae is a member of mitis group streptococci and shares many features with oral mitis group streptococci. In this study, we investigated the effect of viable Streptococcus oralis, a representative member of oral mitis group, on the infectivity of H1N1 IAV...

Members of the oral mitis group streptococci including Streptococcus oralis, Streptococcus sanguinis, and Streptococcus gordonii are the most abundant inhabitants of human oral cavity and dental plaque, and have been implicated in infectious complications such as bacteremia and infective endocarditis. Oral mitis group streptococci are genetically close to Streptococcus pneumoniae; however, they do not produce cytolysin (pneumolysin), which is a key virulence factor of S. pneumoniae. Similar to S. pneumoniae, oral mitis group streptococci possess several cell surface proteins that bind to the cell surface components of host mammalian cells...