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Frontiers in Microbiology 2023The management of infectious diseases has become more critical due to the development of novel pathogenic strains with enhanced resistance. , a gram-negative bacterium,...
The management of infectious diseases has become more critical due to the development of novel pathogenic strains with enhanced resistance. , a gram-negative bacterium, was found to be involved in various infections of the respiratory tract, aerodigestive tract, and gastrointestinal tract. The need to explore novel drug and vaccine targets against this pathogen was triggered by the emergence of antimicrobial resistance against reported antibiotics to combat infections. The study involves core genes acquired from 14 complete strain genome sequences, where promiscuous drug and vaccine candidates were explored by state-of-the-art subtractive proteomics and reverse vaccinology approaches. A stringent bioinformatics analysis enlisted 18 targets as novel, essential, and non-homologous to humans and having druggability potential. Moreover, the extracellular and outer membrane proteins were subjected to antigenicity, allergenicity, and physicochemical analysis for the identification of the candidate proteins to design multi-epitope vaccines. Two candidate proteins (ADK95685.1 and ADK97014.1) were selected as the best target for the designing of a vaccine construct. Lead B- and T-cell overlapped epitopes were joined to generate potential chimeric vaccine constructs in combination with adjuvants and linkers. Finally, a prioritized vaccine construct was found to have stable interactions with the human immune cell receptors as confirmed by molecular docking and MD simulation studies. The vaccine construct was found to have cloning and expression ability in the bacterial cloning system. Immune simulation ensured the elicitation of significant immune responses against the designed vaccine. In conclusion, our study reported novel drug and vaccine targets and designed a multi-epitope vaccine against the infection. Further experimental validation will help open new avenues in the treatment of this multi-drug-resistant pathogen.
PubMed: 37808310
DOI: 10.3389/fmicb.2023.1271798 -
Oral Microbiology and Immunology Dec 1998Strains resembling Prevotella melaninogenica were isolated from healthy subjects and patients with periodontal disease and were identified using: a 5-test phenotypic...
Strains resembling Prevotella melaninogenica were isolated from healthy subjects and patients with periodontal disease and were identified using: a 5-test phenotypic screen; commercial identification kits; and a 16S rRNA-based polymerase chain reaction (PCR) method. Eleven clinical isolates closely resembling P. melaninogenica, and all from patients with periodontitis, were able to agglutinate erythrocytes. In the electron microscope, hemagglutinating isolates showed fimbria-like structures, that were not seen on non-hemagglutinating isolates. Some strains were further classified with PCR-restriction fragment-length polymorphism (RFLP) of 16S rRNA genes. Amplified 16S rDNA was digested using five different endonucleases, separated with agarose gel electrophoresis, stained and photographed. Photographs were then scanned, digitized and a distance matrix calculated using Dice coefficient, where the presence or absence of a band was used as a character. The distance matrix was plotted as a phenogram. At 70% similarity six clusters were seen. Type strains of separate Prevotella species did not fall into any cluster. Hemagglutinating isolates fell into three clusters: four clustered with the type strains of P. melaninogenica and Prevotella veroralis; four with other P. melaninogenica isolates and two hemagglutinating isolates clustered together Prevotella loescheii. The PCR-RFLP results showed that the hemagglutinating strains did not form a homogenous group inside the Prevotella genus.
Topics: Adult; Bacterial Typing Techniques; Fimbriae, Bacterial; Hemagglutination; Humans; Mouth; Periodontal Diseases; Polymerase Chain Reaction; Prevotella melaninogenica
PubMed: 9872112
DOI: 10.1111/j.1399-302x.1998.tb00692.x -
International Journal of Systematic... Oct 1992During studies of human periodontal disease, a number of bacterial strains were encountered that, on the basis of results of standard biochemical tests, appeared to be...
During studies of human periodontal disease, a number of bacterial strains were encountered that, on the basis of results of standard biochemical tests, appeared to be Prevotella buccalis, Prevotella denticola, Prevotella melaninogenica, or Prevotella loescheii. However, use of the standard biochemical tests, cellular fatty acid analyses, and the polyacrylamide gel electrophoresis patterns of soluble proteins resulted in conflicting identifications of these strains. The results of tests for cellobiose fermentation, inulin fermentation, and pigment production were responsible for most of the discordant results. Cellular fatty acid analyses in which the Microbial Identification System was used did not differentiate these strains from validly described species, even though separate library entries were created for them. DNA reassociation determinations in which the S1 nuclease procedure was used showed that cellobiose fermentation and pigment production are variable among strains of P. melaninogenica and P. denticola and that fermentation of xylan is not a reliable characteristic for differentiating P. buccalis from Prevotella veroralis. In contrast to previous indications, most strains of P. veroralis do not ferment xylan. These species can be differentiated by DNA-DNA reassociation and by cellular fatty acid analysis, using the Microbial Identification System, but differentiation by currently described phenotypic characteristics is not reliable. Similarly, P. loescheii and the genetically distinct (but closely related) D1C-20 group cannot be distinguished reliably from each other or from P. veroralis, P. denticola, and P. melaninogenica on the basis of currently described phenotypic tests other than cellular fatty acid composition or, for some species, electrophoretic patterns of soluble whole-cell proteins.
Topics: Bacterial Typing Techniques; Bacteroides; Cellobiose; Culture Media; DNA, Bacterial; Fatty Acids; Fermentation; Humans; Phenotype; Xylans
PubMed: 1390106
DOI: 10.1099/00207713-42-4-536 -
Frontiers in Microbiology 2021is recognized as one of the core anaerobic genera in the oral microbiome. In addition, members of this genus belong to microbial communities of the gastrointestinal and... (Review)
Review
is recognized as one of the core anaerobic genera in the oral microbiome. In addition, members of this genus belong to microbial communities of the gastrointestinal and respiratory tracts. Several novel species, most of them of oral origin, have been described, but limited knowledge is still available of their clinical relevance. is among the anaerobic commensals on oral mucosae from early months of life onward, and other early colonizing species in the oral cavity include and . Oral species get constant access to the gastrointestinal tract via saliva swallowing and to lower airways via microaspiration. At these extra-oral sites, they play a role as commensals but also as potentially harmful agents on mucosal surfaces. The aim of this narrative review is to give an updated overview on the involvement of oral species in gastrointestinal and respiratory health and disease.
PubMed: 35069501
DOI: 10.3389/fmicb.2021.798763 -
Oral Diseases Oct 2014To evaluate the ability of the probiotic strain Lactobacillus brevis CD2 to inhibit the opportunistic anaerobe Prevotella melaninogenica (PM1), a well-known causative...
OBJECTIVE
To evaluate the ability of the probiotic strain Lactobacillus brevis CD2 to inhibit the opportunistic anaerobe Prevotella melaninogenica (PM1), a well-known causative agent of periodontitis.
MATERIALS AND METHODS
The inhibitory effect of Lactobacillus CD2 on Prevotella PM1 biofilm was assessed both by exposing the anaerobe to the supernatant of the probiotic strain and by growing the two strains to obtain single or mixed biofilms. The inhibitory effect of CD2 on PM1 was also checked by the agar overlay method.
RESULTS
The development of PM1 biofilm was strongly affected (56% decrease in OD value) by the CD2 supernatant after 96 h. A dose-dependent biofilm reduction was also observed at 1/10 and 1/100 dilutions of supernatant. Confocal microscopy on the mixed biofilms revealed the ability of CD2 to prevail on PM1, greatly reducing the biofilm of the latter.
CONCLUSIONS
It has been hypothesized a multifactorial nature of the inhibition mechanism, the strong adherence ability of CD2 strain together with the released metabolites presumably contributing to the reduction in the PM1 biofilm detected by confocal microscopy.
Topics: Bacterial Physiological Phenomena; Biofilms; Levilactobacillus brevis; Prevotella melaninogenica; Probiotics
PubMed: 24118283
DOI: 10.1111/odi.12186 -
The American Journal of Emergency... Sep 2020An 85-year-old cachectic man was found unconscious in his home. He had no specific medical history. On arrival, he was in a deep coma and hypothermic state. He had a...
An 85-year-old cachectic man was found unconscious in his home. He had no specific medical history. On arrival, he was in a deep coma and hypothermic state. He had a soft mass the size of his fist in the right lower abdomen without redness or heat. Truncal computed tomography revealed subcutaneous fluid collection with gas formation. A test puncture for right lower abdominal subcutaneous fluid collection revealed pus, so an open incision was performed, with the administration of broad-spectrum antibiotics. Unfortunately, the patient died of sepsis-induced multiple organ failure. The results of abscess culture later revealed Proteus mirabilis, Escherichia coli, and Prevotella melaninogenica. This is the first report of a cold abscess induced by mixed bacteria.
Topics: Abdominal Abscess; Aged, 80 and over; Coma; Fatal Outcome; Humans; Male; Tomography, X-Ray Computed
PubMed: 32444294
DOI: 10.1016/j.ajem.2020.04.096 -
Microbiology and Immunology Sep 2018Prevotella melaninogenica is a gram-negative anaerobic commensal bacterium that resides in the human oral cavity and is isolated as a pathogen of suppurative diseases...
Prevotella melaninogenica is a gram-negative anaerobic commensal bacterium that resides in the human oral cavity and is isolated as a pathogen of suppurative diseases both inside and outside the mouth. However, little is known about the pathogenic factors of P. melaninogenica. The periodontal pathogens Porphyromonas gingivalis and Tanerella forsythia secrete virulence factors such as protease and bacterial cell surface proteins via a type IX secretion system (T9SS) that are involved in pathogenicity. P. melaninogenica also possesses all known orthologs of T9SS. In this study, a P. melaninogenica GAI 07411 mutant deficient in the orthologue of the T9SS-encoding gene, porK, was constructed. Hemagglutination and biofilm formation were decreased in the porK mutant. Furthermore, following growth on skim milk-containing medium, the diameters of the halos surrounding the porK mutant were smaller than those of the wild-type strain, suggesting a decrease in secretion of proteases outside the bacterium. To investigate this in detail, culture supernatants of wild-type and porK mutant strains were purified and compared by two-dimensional electrophoresis. In the mutant strain, fewer spots were detected, indicating fewer secreted proteins. In infection experiments, the mortality rate of mice inoculated with the porK mutant strain was significantly lower than in the wild-type strain. These results suggest that P. melaninogenica secretes potent virulence factors via the T9SS that contribute to its pathogenic ability.
Topics: Animals; Bacterial Proteins; Bacterial Secretion Systems; Bacteroidaceae Infections; Biofilms; Female; Gene Expression Profiling; Genes, Bacterial; Genetic Loci; Hemagglutination; Membrane Transport Proteins; Mice; Mice, Inbred BALB C; Mortality; Mouth; Mutation; Peptide Hydrolases; Periodontal Diseases; Prevotella melaninogenica; Virulence; Virulence Factors
PubMed: 30028034
DOI: 10.1111/1348-0421.12638 -
Oral Microbiology and Immunology Dec 1991Human isolates of Porphyromonas gingivalis (n = 16), Prevotella intermedia n = 82) and Prevotella melaninogenica (n = 18) from diseased periodontal pockets were examined... (Comparative Study)
Comparative Study
Human isolates of Porphyromonas gingivalis (n = 16), Prevotella intermedia n = 82) and Prevotella melaninogenica (n = 18) from diseased periodontal pockets were examined for interaction with human lactoferrin (HLf) in a standardized 125I-labeled protein binding assay. The highest HLf binding was found in P. intermedia strains, followed by P. gingivalis and P. melaninogenica. Further characterization of the interaction was performed with 1 representative strain from each species. HLf binding to P. gingivalis reached a saturation instantly and was optimal at pH 5.0-6.5. The corresponding values for P. melaninogenica were 90 min and pH 3.0-5.5. The HLf binding to the 2 strains seem to be nonspecific. In contrast, P. intermedia demonstrated specific binding, and a time-saturability within 60 min with an optimal uptake at pH 6.0-7.5. Scatchard analysis implied 45,000 receptors per cell with an affinity constant of 5.5 x 10(-7) M on P. intermedia strain 4H. The binding capacity in all 3 strains was affected by the culture medium. HLf binding components in these strains were susceptible to heat or proteases. Binding was eliminated in P. gingivalis and was enhanced in P. intermedia and P. melaninogenica by periodate treatment. Unlabeled HLf or bovine lactoferrin effectively displaced labeled HLf binding. Various proteins and carbohydrates did not inhibit HLf binding. Our data suggest that HLf binds to these periodontitis-associated species and that this mechanism is distinct from the previously known ligand interactions in oral bacteria.
Topics: Acute-Phase Proteins; Bacteroides; Binding, Competitive; Humans; Lactoferrin; Periodontitis; Porphyromonas gingivalis; Prevotella melaninogenica; Protein Binding; Salivary Proteins and Peptides
PubMed: 1726544
DOI: 10.1111/j.1399-302x.1991.tb00506.x -
European Review For Medical and... Mar 2019Probiotics S. salivarius 24SMBc and S. oralis 89a comprised in the nasal spray Rinogermina are known to exert inhibition of harmful pathogens and ameliorate the outcome... (Clinical Trial)
Clinical Trial
Modulation of opportunistic species Corynebacterium diphtheriae, Haemophilus parainfluenzae, Moraxella catarrhalis, Prevotella denticola, Prevotella melaninogenica, Rothia dentocariosa, Staphylococcus aureus and Streptococcus pseudopneumoniae by intranasal administration of Streptococcus salivarius...
OBJECTIVE
Probiotics S. salivarius 24SMBc and S. oralis 89a comprised in the nasal spray Rinogermina are known to exert inhibition of harmful pathogens and ameliorate the outcome of patients with chronic upper airways infections. In this study, for the first time, the effect of this formulation on the modulation of the microflora of healthy subjects was evaluated, with particular interest on pathobionts and pathogens present.
PATIENTS AND METHODS
Metagenomic identification and quantification of bacterial abundances in healthy subjects were carried out by means of Ion Torrent Personal Machine. In particular, nasal swabs were sampled one, two and four weeks after seven days of treatment with Rinogermina.
RESULTS
The modulation of the abundance of pathobionts and pathogenic species (i.e., Corynebacterium diphtheriae, Haemophilus parainfluenzae, Moraxella catarrhalis, Prevotella denticola, Prevotella melaninogenica, Rothia dentocariosa, Staphylococcus aureus and Streptococcus pseudopneumoniae) was characterized and a significant temporary decrease in their presence was identified.
CONCLUSIONS
The beneficial effects of S. salivarius 24SMBc and S. oralis 89a nasal intake was assessed but seemed to be restricted in specific temporal windows. Thus it would be interesting to evaluate also this positive impact of longer administration of this probiotic formulation.
Topics: Administration, Intranasal; Adult; Female; Healthy Volunteers; Humans; Male; Microbiota; Middle Aged; Nose; Probiotics; Streptococcus oralis; Streptococcus salivarius; Time Factors; Young Adult
PubMed: 30920634
DOI: 10.26355/eurrev_201903_17351 -
The Journal of Clinical Pediatric... 2008A relationship between the distribution of periodontal bacteria species and malodor in children has not been sufficiently investigated. The present study was undertaken...
PURPOSE
A relationship between the distribution of periodontal bacteria species and malodor in children has not been sufficiently investigated. The present study was undertaken to determine the presence of 3 periodontopathic bacteria (Prevotella spp. P. intermedia, P. nigrescens, P. melaninogenica) in the supragingival plaques of 3 to 16-year-old children with different oral health conditions and oral malodor.
METHODS
The number of decayed and filled primary teeth (df) and Decayed, Missing and Filled permanent teeth (DMF), Papillary Marginal and Attached gingivitis (PMA) index, Oral Hygiene Index (OHI), and oral malodor of each subject were determined prior to the collection of supragingival plaques. Three periodontopathic bacteria (P. intermedia, P. nigrescens, P. melaninogenica) in supragingival plaques were detected by using an immunoslot blot assay with monoclonal antibodies specific for each microorganism.
FINDINGS
The frequencies of periodontopathic bacteria in children with and without caries were not significantly different from each other. Positivity for P. intermedia, but not for P. nigrescens or P. melaninogenica was correlated with oral malodor. Oral malodor was also correlated with the debris index, a component of OHI. The group with the higher OHI showed a higher prevalence of periodontopathic bacteria. For the 3 periodontopathic bacteria in the subjects tested, plaques positive for any of them were not age related. However the frequencies of all 3 periodontopathic bacteria were the highest in the 3-6-year olds.
CONCLUSION
The supragingival plaques in children can harbor 3 species of periodontopathic bacteria, P. intermedia, P. nigrescens, and P. melaninogenica.
Topics: Adolescent; Analysis of Variance; Child; Child, Preschool; Dental Caries; Dental Plaque; Female; Halitosis; Humans; Immunoblotting; Male; Oral Hygiene Index; Prevotella intermedia; Prevotella melaninogenica; Prevotella nigrescens
PubMed: 18524268
DOI: 10.17796/jcpd.32.3.vp657177815618l1