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Journal of Gastrointestinal Oncology Aug 2018Colorectal cancer (CRC) is the third most common newly diagnosed cancer in both men and women in the Unites States. Colonoscopy has become increasingly popular in CRC... (Review)
Review
Colorectal cancer (CRC) is the third most common newly diagnosed cancer in both men and women in the Unites States. Colonoscopy has become increasingly popular in CRC screening and represents the gold standard for detecting and removing pre-cancerous lesions. Although colonoscopy is considered a relatively safe procedure, it is invasive and bowel preparation can be challenging for patients. As interest in the gut microbiome has expanded, there have been new links established between bacteria and the development of CRC. These developing associations could prove to be a useful adjunct to colonoscopy for CRC screening in the future. This review examines current research evaluating multiple proposed pathogenic microorganisms including sulfidogenic bacteria such as , as well as , and . This discussion primarily focuses on bacterial pathogenesis, evidence of association with CRC, and the proposed mechanisms of carcinogenesis.
PubMed: 30151274
DOI: 10.21037/jgo.2018.04.07 -
Enfermedades Infecciosas Y... Apr 2023Streptococcus bovis/equinus complex (SBEC) is a major cause of infective endocarditis (IE), although its incidence varies greatly depending on the geographical area. The...
INTRODUCTION
Streptococcus bovis/equinus complex (SBEC) is a major cause of infective endocarditis (IE), although its incidence varies greatly depending on the geographical area. The characteristics of IE caused by Streptococcus gallolyticus susp. gallolyticus are well known; there are hardly any descriptions of IE caused by other species or biotypes.
METHODS
Retrospective cohort study, from 1990 to 2019, of all SBEC IE in adults in three Spanish hospitals, Lugo (LH), Barcelona (BH) and Ferrol (FH) where the population is mainly rural, urban and mixed, respectively. The incidence of IE was analyzed in 3 areas. Clinical characteristics of IE (277 cases, 258 biotyped) were compared according to SBEC species and biotypes.
RESULTS
There are significant differences between the incidence of SBEC IE in HL (27.9/10) vs. HF and HB (8.8 and 7,1, respectively, p<0.001). We found significant differences (SbI vs. SbII) in mean age (68.5 vs. 73 years; p<0.01), duration of symptoms before diagnosis (46.9±46.5 vs. 30.4±40.9 days; p<0.01), presence of comorbidities: 39.1% (78) vs. 54.2% (32; p<0.04), predisposing heart illness:62.3% (124) vs. 81.3% (48; p<0.006), particularly, prosthetic or intravascular devices IE: 24.6% (49) vs. 52.4% (31; p<0.001), bi-valve involvement:23.6% (47) vs. 11.8% (7; p<0.05) and heart failure: 24.6% (49) vs. 38.9% (23; p<0.03). There were no significant differences in embolic events, need for surgery or mortality. The association with CRC was high in both groups: 77.7% vs. 66.6%.
CONCLUSIONS
IE due to SBEC has geographical variations in incidence and different clinical characteristics among biotypes. The association with CRC was high.
Topics: Adult; Humans; Streptococcus bovis; Retrospective Studies; Streptococcal Infections; Endocarditis, Bacterial; Endocarditis
PubMed: 36610830
DOI: 10.1016/j.eimce.2021.08.017 -
Animal : An International Journal of... Jun 2013Vaccination against rumen methanogens offers a practical approach to reduce methane emissions in livestock, particularly ruminants grazing on pasture. Although... (Review)
Review
Vaccination against rumen methanogens offers a practical approach to reduce methane emissions in livestock, particularly ruminants grazing on pasture. Although successful vaccination strategies have been reported for reducing the activity of the rumen-dwelling organism Streptococcus bovis in sheep and S. bovis and Lactobacillus spp. in cattle, earlier approaches using vaccines based on whole methanogen cells to reduce methane production in sheep have produced less promising results. An anti-methanogen vaccine will need to have broad specificity against methanogens commonly found in the rumen and induce antibody in saliva resulting in delivery of sufficiently high levels of antibodies to the rumen to reduce methanogen activity. Our approach has focussed on identifying surface and membrane-associated proteins that are conserved across a range of rumen methanogens. The identification of potential vaccine antigens has been assisted by recent advances in the knowledge of rumen methanogen genomes. Methanogen surface proteins have been shown to be immunogenic in ruminants and vaccination of sheep with these proteins induced specific antibody responses in saliva and rumen contents. Current studies are directed towards identifying key candidate antigens and investigating the level and types of salivary antibodies produced in sheep and cattle vaccinated with methanogen proteins, stability of antibodies in the rumen and their impact on rumen microbial populations. In addition, there is a need to identify adjuvants that stimulate high levels of salivary antibody and are suitable for formulating with protein antigens to produce a low-cost and effective vaccine.
Topics: Animals; Bacteria; Bacterial Vaccines; Cattle; Eukaryota; Euryarchaeota; Methane; Protozoan Vaccines; Rumen; Sheep
PubMed: 23739467
DOI: 10.1017/S1751731113000682 -
Frontiers in Oncology 2022Gut microbiome plays a crucial role in the formation and progression of colorectal cancer (CRC). To better identify the underlying gene-level pathogenic mechanisms of...
BACKGROUND
Gut microbiome plays a crucial role in the formation and progression of colorectal cancer (CRC). To better identify the underlying gene-level pathogenic mechanisms of microbiome-associated CRC, we applied our newly developed Reverse Microbiomics (RM) to predict potential pathogenic factors using the data of microbiomes in CRC patients.
RESULTS
Our literature search first identified 40 bacterial species enriched and 23 species depleted in the guts of CRC patients. These bacteria were systematically modeled and analyzed using the NCBI Taxonomy ontology. Ten species, including 6 enriched species (e.g., , and ) and 4 depleted species (e.g., and ) were chosen for follow-up comparative genomics analysis. Vaxign was used to comparatively analyze 47 genome sequences of these ten species. In total 18 autoantigens were predicted to contribute to CRC formation, six of which were reported with experimental evidence to be correlated with drug resistance and/or cell invasiveness of CRC. Interestingly, four human homology proteins (EDK89078.1, EDK87700.1, EDK89777.1, and EDK89145.1) are conserved among all enriched strains. Furthermore, we predicted 76 potential virulence factors without homology to human proteins, including two riboflavin synthase proteins, three ATP-binding cassettes (ABC) transporter protein family proteins, and 12 outer membrane proteins (OMPs). Riboflavin synthase is present in all the enriched strains but not in depleted species. The critical role of riboflavin synthase in CRC development was further identified from its hub role in our STRING-based protein-protein interaction (PPI) network analysis and from the finding of the riboflavin metabolism as the most significantly enriched pathway in our KEGG pathway analysis. A novel model of the CRC pathogenesis involving riboflavin synthase and other related proteins including TpiA and GrxC was further proposed.
CONCLUSIONS
The RM strategy was used to predict 18 autoantigens and 76 potential virulence factors from CRC-associated microbiome data. In addition to many of these autoantigens and virulence factors experimentally verified as reported in the literature, our study predicted many new pathogenetic factors and developed a new model of CRC pathogenesis involving the riboflavin synthase from the enriched colorectal bacteria and other associated proteins.
PubMed: 35574378
DOI: 10.3389/fonc.2022.882874 -
European Journal of Case Reports in... 2019We describe a case of infective endocarditis occurring in a patient following colonic polypectomy. The patient had multiple risk factors for infective endocarditis...
UNLABELLED
We describe a case of infective endocarditis occurring in a patient following colonic polypectomy. The patient had multiple risk factors for infective endocarditis including pre-existing mitral valve prolapse and regurgitation. Transoesophageal echocardiography revealed a friable mass on the posterior mitral valve leaflet, confirming the diagnosis. The patient was treated with intravenous antibiotics, successfully underwent mitral valve surgery and was discharged home for outpatient follow-up. This report details an uncommon case presentation, highlights areas for improvement in clinical practice, and summarises the current knowledge available in the literature regarding infective endocarditis.
LEARNING POINTS
Infective endocarditis occurring in association with gastrointestinal endoscopy is rare.Clinical suspicion of infective endocarditis after colonic polypectomy or biopsy should be maintained, especially in those with risk factors for infective endocarditis.Antibiotic prophylaxis against infective endocarditis is not recommended for routine gastrointestinal endoscopic procedures.
PubMed: 31157186
DOI: 10.12890/2019_001110 -
Microorganisms Mar 2022Antimicrobial peptides (AMPs) can efficiently control different microbial pathogens and show the potential to be applied in clinical practice and livestock production....
Antimicrobial peptides (AMPs) can efficiently control different microbial pathogens and show the potential to be applied in clinical practice and livestock production. In this work, the aim was to isolate AMP-producing ruminal streptococci and to characterize their genetic features through whole-genome sequencing. We cultured 463 bacterial isolates from the rumen of Nelore bulls, 81 of which were phenotypically classified as being . Five isolates with broad-range activity were genome sequenced and confirmed as being . The genetic features linked to their antimicrobial activity or adaptation to the rumen environment were characterized through comparative genomics. The genome of UFV80 harbored a putative CRISPR-Cas9 system (Type IIA). Computational tools were used to discover novel biosynthetic clusters linked to the production of bacteriocins. All bacterial genomes harbored genetic clusters related to the biosynthesis of class I and class II bacteriocins. SDS-PAGE confirmed the results obtained in silico and demonstrated that the class II bacteriocins predicted in the genomes of three strains had identical molecular mass (5197 Da). These results demonstrate that ruminal bacteria of the / complex represent a promising source of novel antimicrobial peptides.
PubMed: 35336126
DOI: 10.3390/microorganisms10030551 -
Clinical Microbiology Reviews Oct 2002Since the division of the Streptococcus genus into enterococci, lactococci, and streptococci in 1984, many changes in the nomenclature and taxonomy of the Streptococcus... (Review)
Review
Since the division of the Streptococcus genus into enterococci, lactococci, and streptococci in 1984, many changes in the nomenclature and taxonomy of the Streptococcus genus have taken place. The application of genetic comparisons has improved the proper classification of the different species. The Lancefield system of serogrouping the streptococci by the expression of beta-hemolysis on blood agar plates is still very useful for the identification of streptococci for patient management. The Lancefield grouping system cannot be used in itself for accurate identification of specific beta-hemolytic species, but it can be a useful part of the identification procedure. Except for identification of the "Streptococcus bovis group" of species and Streptococcus suis, Lancefield grouping is of little value in identification of the non-beta-hemolytic streptococci and related genera. In fact, identification of the non-beta-hemolytic species is problematic for conventional as well as commercially available identification procedures. A combination of conventional tests and specific chromogenic tests suggested by several investigators is presented and discussed. Tables are included that suggest tests and procedures to guide investigators attempting to identify all the species.
Topics: Streptococcus; Terminology as Topic
PubMed: 12364372
DOI: 10.1128/CMR.15.4.613-630.2002 -
Microorganisms Feb 2023Nisin A, the prototypical lantibiotic, is an antimicrobial peptide currently utilised as a food preservative, with potential for therapeutic applications. Here, we...
Nisin A, the prototypical lantibiotic, is an antimicrobial peptide currently utilised as a food preservative, with potential for therapeutic applications. Here, we describe nisin E, a novel nisin variant produced by two strains, APC4007 and APC4008, isolated from sheep milk. Shotgun whole genome sequencing and analysis revealed biosynthetic gene clusters similar to nisin U, with a unique rearrangement of the core peptide encoding gene within the cluster. The 3100.8 Da peptide by MALDI-TOF mass spectrometry, is 75% identical to nisin A, with 10 differences, including 2 deletions: Ser29 and Ile30, and 8 substitutions: Ile4Lys, Gly18Thr, Asn20Pro, Met21Ile, His27Gly, Val32Phe, Ser33Gly, and Lys34Asn. Nisin E producing strains inhibited species of , , and and were immune to nisin U. Sequence alignment identified putative promoter sequences across the nisin producer genera, allowing for the prediction of genes in to be potentially regulated by nisin. pangenome BLAST analyses detected 6 nisin E operons across 44 publicly available genomes. An additional 20 genomes contained a subset of nisin E transport/immunity and regulatory genes (), without adjacent peptide production genes. These genes suggest that nisin E response mechanisms, distinct from the canonical nisin immunity and resistance operons, are widespread across the species. The discovery of this new nisin variant and its immunity determinants in suggests a central role for nisin in the competitive nature of the species.
PubMed: 36838392
DOI: 10.3390/microorganisms11020427 -
Journal of Clinical Microbiology Jul 2016The Streptococcus bovis group has undergone significant taxonomic changes over the past 2 decades with the advent of new identification methods with higher... (Review)
Review
The Streptococcus bovis group has undergone significant taxonomic changes over the past 2 decades with the advent of new identification methods with higher discriminatory power. Although the current classification system is not yet embraced by all researchers in the field and debate remains over the performance of molecular techniques for identification to the species level within the group, important disease associations for several members of the group have been clarified. Here, we provide a brief overview of the history of the S. bovis group, an outline of the currently accepted classification scheme, a review of associated clinical syndromes, and a summary of the performance and diagnostic accuracy of currently available identification methods.
Topics: Bacteriological Techniques; Humans; Molecular Diagnostic Techniques; Streptococcal Infections; Streptococcus bovis
PubMed: 26912760
DOI: 10.1128/JCM.02977-15 -
Journal of Clinical Microbiology Sep 2008Modern taxonomy has delineated Streptococcus gallolyticus subsp. gallolyticus, S. gallolyticus subsp. pasteurianus, Streptococcus infantarius subsp. coli, and S....
Comprehensive study of strains previously designated Streptococcus bovis consecutively isolated from human blood cultures and emended description of Streptococcus gallolyticus and Streptococcus infantarius subsp. coli.
Modern taxonomy has delineated Streptococcus gallolyticus subsp. gallolyticus, S. gallolyticus subsp. pasteurianus, Streptococcus infantarius subsp. coli, and S. infantarius subsp. infantarius within the heterogenous group of previously designated clinical Streptococcus bovis bacteria. In the present study, 58 consecutive blood culture isolates initially designated S. bovis were further characterized by applying phenotypic and molecular genetic methods, and possible disease associations were investigated by studying the patients' records. Published phenotypic characteristics of S. gallolyticus and S. infantarius were not unequivocal and did not allow an unambiguous phenotypic differentiation of the 58 clinical isolates. However, full-length 16S rRNA gene sequences clearly assigned the strains to S. gallolyticus subsp. gallolyticus (n = 29), S. gallolyticus subsp. pasteurianus (n = 12), and S. infantarius subsp. coli (n = 17). Only 28% of the patients with available records presented with endocarditis and 7% presented with colon carcinoma, whereas 37% of the patients had altered liver parenchyma and 28% had gall bladder disease as underlying diseases. Detailed antimicrobial susceptibility data on both S. gallolyticus subspecies and S. infantarius subsp. coli are given for the first time. As a result of the extensive characterization of the largest number of S. gallolyticus and S. infantarius human clinical isolates published so far, emended species descriptions are given. It is recommended that both clinical microbiologists and infectious disease specialists avoid the designation S. bovis for true S. gallolyticus and S. infantarius strains in the future in order to get a clearer picture of the possible disease associations of these species.
Topics: Adult; Aged; Aged, 80 and over; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Molecular Sequence Data; Phenotype; Streptococcal Infections; Streptococcus; Streptococcus bovis
PubMed: 18614655
DOI: 10.1128/JCM.00078-08