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Microorganisms Jun 2021The importance and abundance of strict anaerobic bacteria in the respiratory microbiota of people with cystic fibrosis (PWCF) is now established through studies based on...
The importance and abundance of strict anaerobic bacteria in the respiratory microbiota of people with cystic fibrosis (PWCF) is now established through studies based on high-throughput sequencing or extended-culture methods. In CF respiratory niche, one of the most prevalent anaerobic genera is , and particularly the species The objective of this study was to evaluate the antibiotic susceptibility of this anaerobic species. Fifty isolates of cultured from sputum of 50 PWCF have been included. Antibiotic susceptibility testing was performed using the agar diffusion method. All isolates were susceptible to the following antibiotics: amoxicillin/clavulanic acid, piperacillin/tazobactam, imipenem and metronidazole. A total of 96% of the isolates (48/50) were resistant to amoxicillin (indicating beta-lactamase production), 34% to clindamycin (17/50) and 24% to moxifloxacin (12/50). Moreover, 10% (5/50) were multidrug-resistant. A significant and positive correlation was found between clindamycin resistance and chronic azithromycin administration. This preliminary study on a predominant species of the lung "anaerobiome" shows high percentages of resistance, potentially exacerbated by the initiation of long-term antibiotic therapy in PWCF. The anaerobic resistome characterization, focusing on species rather than genera, is needed in the future to better prevent the emergence of resistance within lung microbiota.
PubMed: 34208093
DOI: 10.3390/microorganisms9061275 -
Clinical and Experimental Immunology Aug 2022Oral lichen planus (OLP) is a common chronic inflammatory disease occurring in the oral mucosa. Bacteria are a key driver of mucosal immune responses and can induce...
Oral lichen planus (OLP) is a common chronic inflammatory disease occurring in the oral mucosa. Bacteria are a key driver of mucosal immune responses and can induce changes in gene expression and function of epithelial keratinocytes. IL-36γ can induce the expression of antimicrobial peptides, cytokines, and chemokines, and is widely involved in many chronic inflammatory diseases. Our aim is to explore the role of IL-36γ in the pathological process of OLP when Prevotella melaninogenica (P. melaninogenica) invades the oral mucosa. The expression of IL-36γ in OLP lesions and mice was detected by immunohistochemistry. Recombinant human IL-36Gamma (rhIL-36γ) was used to treat oral keratinocytes and the expression levels of inflammatory cytokines were detected by qRT-PCR and ELISA. The expression of IL-36γ and TRPV1 was detected by western blotting following co-culturing P. melaninogenica with oral keratinocytes. The mRNA expression of IL-36γ was detected by qRT-PCR. From our results, IL-36γ was upregulated in OLP lesions. Exogenous rhIL-36γ promoted the expression of pro-inflammatory cytokines and antibacterial peptides in oral keratinocytes. The expression of IL-36γ was significantly increased following the stimulation of P. melaninogenica in oral keratinocytes and mice. TRPV1 activation was induced by P. melaninogenica and its activation enhanced the expression of IL-36γ. IL-36Ra could reduce the inflammation in OLP in vitro. In summary, overexpression of IL-36γ in OLP lesions could promote its pathogenesis by inducing inflammation. P. melaninogenica invasion of oral keratinocytes could induce the expression of IL-36γ by the activation of TRPV1, thereby regulating the interaction between bacteria and oral epithelial cells.
Topics: Animals; Cytokines; Humans; Inflammation; Keratinocytes; Lichen Planus, Oral; Mice; Prevotella melaninogenica
PubMed: 35605143
DOI: 10.1093/cei/uxac054 -
Oral Diseases Sep 2022Oral lichen planus (OLP) is a chronic inflammatory disease that occurs in the oral mucosa with characteristic white striations lesions, recurrent erosions, and pains....
OBJECTIVE
Oral lichen planus (OLP) is a chronic inflammatory disease that occurs in the oral mucosa with characteristic white striations lesions, recurrent erosions, and pains. The etiology and pathogenesis of OLP are still unclear.
MATERIALS AND METHODS
We analyzed the bacterial community structure of buccal mucosa in patients with OLP and normal controls by high-throughput sequencing. Fluorescence in situ hybridization (FISH) was used to detect Prevotella melaninogenica (P. melaninogenica) in 13 OLP samples and 10 controls. The amounts of P. melaninogenica in OLP buccal mucosa and the expression of inflammatory cytokines in co-culture of mouse-derived macrophages with P. melaninogenica were detected by RT-qPCR.
RESULTS
The P. melaninogenica was more abundant in OLP than in healthy controls, and the differences were significant at the level of the phylum, family, genus, and species (p < .05). FISH showed that P. melaninogenica can invade the epithelium and even the lamina propria of OLP, while no invasion was found in the normal mucosa. Prevotella melaninogenica can adhere to and invade macrophages and then activate the transcription of IL-1β, IL-6, and TNF-α in NF-κB signaling pathway.
CONCLUSION
Prevotella melaninogenica may be involved in the pathogenic process of OLP, and its specific mechanism deserves further study.
Topics: Animals; Cytokines; In Situ Hybridization, Fluorescence; Lichen Planus, Oral; Mice; Mouth Mucosa; Prevotella melaninogenica
PubMed: 33780104
DOI: 10.1111/odi.13862 -
Journal of Indian Society of... 2023is a Gram-negative anaerobic bacilli. The phenotypic characteristics of the various species of are similar, which often makes it difficult in routine differentiation...
Simultaneous detection and evaluation of , and in subgingival plaque samples of chronic periodontitis and healthy individuals through multiplex polymerase chain reaction.
BACKGROUND
is a Gram-negative anaerobic bacilli. The phenotypic characteristics of the various species of are similar, which often makes it difficult in routine differentiation and identification of all the species.
AIM
The purpose of the study was to detect and compare presence of , and in subgingival plaque samples of chronic periodontitis and healthy individuals.
MATERIALS AND METHODS
Two hundred and thirty-six subjects were considered consisting of chronic periodontitis (128) and healthy (108) individuals. Subgingival plaque sample was collected in reduced transport fluid and analyzed. DNA extraction and polymerase chain reaction (PCR) were performed for genus followed by positive samples were considered for the detection of selected species through multiplex PCR using specific primers.
RESULTS
Out of 236 samples, 94.1% were positive for genus . Out of 222 cases showed the highest number of cases positive (59.5%) followed by (57.2%), (55.4%), and (40.1%). Species were analyzed individually between chronic periodontitis and healthy, , and showed greater positivity in healthy compared to chronic periodontitis. Positivity for was high in chronic periodontitis compared to healthy.
CONCLUSION
The number of positive cases for species, when correlated with clinical parameters showed an increase in mean score for all clinical parameters assessed, suggesting the presence of variation in the prevalence of species and geographic variation do exist in oral microflora. Findings suggest that they can be normal commensals and opportunistic.
PubMed: 37346862
DOI: 10.4103/jisp.jisp_154_22 -
Pathogens (Basel, Switzerland) Sep 2023Oral microbiome disruptions in periodontitis are related to the chronic inflammatory reactions that could in turn lead to the development of multiple oral diseases. The...
Oral microbiome disruptions in periodontitis are related to the chronic inflammatory reactions that could in turn lead to the development of multiple oral diseases. The objective of the study was to assess the frequencies of , , and in oral benign lesions, oral potentially malignant disorders (OPMDs), and oral squamous cell carcinomas (OSCCs) and investigate the impact of these bacteria on the expression patterns of the selected (potential) target genes (//, /, and ). After sample collection (25 benign lesions, 30 OPMDs, and 35 OSCCs) and DNA/RNA extraction, quantitative real-time polymerase chain reaction (qPCR) was performed to detect bacterial presence and assess relative gene expression levels in different lesion groups. was the most prevalent of the three analyzed bacteria, with the frequency being 60% in benign lesions, 87% in OPMDs ( = 0.024), and 77% in OSCC. The OPMD tissues in which was present exhibited a higher expression level of ( = 0.042). Significantly lower expression of was observed in OSCC tissues containing ( = 0.011). The obtained results indicate a substantial contribution of and in the pathogenesis of oral mucosal lesions, possibly via upregulation and downregulation.
PubMed: 37887710
DOI: 10.3390/pathogens12101194 -
Methods in Molecular Biology (Clifton,... 2021Prevotella melaninogenica is a bacterium that is resident in the oral cavity and upper respiratory tract and is associated with periodontal disease and aspiration...
Prevotella melaninogenica is a bacterium that is resident in the oral cavity and upper respiratory tract and is associated with periodontal disease and aspiration pneumonia. Prevotella mutants are difficult to produce and only few reports have been reported. We examined several methods and many strains and succeeded in producing mutants in Prevotella melaninogenica GAI 07411. In this chapter, we will describe how to create a mutation of a target gene by carrying out conjugation transfer using Escherichia coli S17-1 as a donor and introducing a plasmid into P. melaninogenica.
Topics: Animals; Escherichia coli; Mouth; Mutation; Periodontal Diseases; Prevotella melaninogenica; Rabbits
PubMed: 32815125
DOI: 10.1007/978-1-0716-0939-2_4 -
Journal of Alzheimer's Disease : JAD 2020Microbial agents including periodontal pathogens have recently appeared as important actors in Alzheimer's disease (AD) pathology. We examined associations of clinical...
Microbial agents including periodontal pathogens have recently appeared as important actors in Alzheimer's disease (AD) pathology. We examined associations of clinical periodontal and bacterial parameters with incident all-cause and AD dementia as well as AD mortality among US middle-aged and older adults. Clinical [Attachment Loss (AL); probing pocket depth (PPD)] and bacterial [pathogen immunoglobulin G (IgG)] periodontal markers were investigated in relation to AD and all-cause dementia incidence and to AD mortality, using data from the third National Health and Nutrition Examination Surveys (NHANES III, 1988-1994) linked longitudinally with National Death Index and Medicare data through January 1, 2014, with up to 26 years of follow-up. Sex- and age-specific multivariable-adjusted Cox proportional hazards models were conducted. Among those ≥65 years, AD incidence and mortality were consistently associated with PPD, two factors and one cluster comprised of IgG titers against Porphyromonas gingivalis (P. gingivalis), Prevotella melaninogenica (P. melaninogenica) and Campylobacter rectus (C. rectus) among others. Specifically, AD incidence was linked to a composite of C. rectus and P. gingivalis titers (per SD, aHR = 1.22; 95% CI, 1.04-1.43, p = 0.012), while AD mortality risk was increased with another composite (per SD, aHR = 1.46; 95% CI, 1.09-1.96, p = 0.017) loading highly on IgG for P. gingivalis, Prevotella intermedia, Prevotella nigrescens, Fusobacterium nucleatum, C. rectus, Streptococcus intermedius, Capnocylophaga Ochracea, and P. melaninogenica. This study provides evidence for an association between periodontal pathogens and AD, which was stronger for older adults. Effectiveness of periodontal pathogen treatment on reducing sequelae of neurodegeneration should be tested in randomized controlled trials.
Topics: Aged; Alzheimer Disease; Campylobacter rectus; Dementia; Female; Health Surveys; Humans; Incidence; Male; Middle Aged; Periodontitis; Porphyromonas gingivalis; Prevotella melaninogenica; United States
PubMed: 32280099
DOI: 10.3233/JAD-200064 -
Antibiotics (Basel, Switzerland) Jul 2022The genus is a normal constituent of the oral microbiota, and is commonly isolated from mechanically treated polymicrobial infections. However, antibiotic treatment is...
The genus is a normal constituent of the oral microbiota, and is commonly isolated from mechanically treated polymicrobial infections. However, antibiotic treatment is necessary for some patients. This study compared the antibiotic susceptibility and the presence of resistance genes in clinical oral isolates of , , and . Antibiotic susceptibility was assessed using the agar dilution method. PCR confirmed the species and resistance gene frequency in the species. The frequencies of species , , and were 30.2%, 45.7%, and 24.1%, respectively. No isolates of were resistant to amoxicillin/clavulanic acid, tetracycline, or clindamycin. and were resistant to amoxicillin/clavulanic acid and tetracycline at frequencies of 40% and 20%, respectively. was resistant to metronidazole at a frequency of 30%, at 20%, and at 40%. and were resistant to 50% and 10% clindamycin, respectively. The gene most frequently detected was , at 43.3%, followed by at 36.6%, at 26.6%, at 20%, , , and at 16.6%, and at 3.3%. was the species with the highest resistance to antibiotics such as amoxicillin/clavulanic acid, amoxicillin, and clindamycin, in addition to being the species with the largest number of genes compared to and
PubMed: 35884141
DOI: 10.3390/antibiotics11070888 -
Oral Diseases May 2024Our previous studies have found that the composition ratio of Prevotella melaninogenica (Pm) on buccal mucosa surface of oral lichen planus (OLP) patients increased...
OBJECTIVE
Our previous studies have found that the composition ratio of Prevotella melaninogenica (Pm) on buccal mucosa surface of oral lichen planus (OLP) patients increased significantly compared with control. Furthermore, Pm could invade the epithelium of OLP patients. This study aimed to further explore the impact of Pm on oral keratinocytes.
MATERIALS AND METHODS
The Pm-human oral keratinocyte (HOK) co-culture model was established to detect monolayer permeability, zona occludens-1 (ZO-1) expression, and intracellular survival of Pm. We performed RNA-seq followed by identification of differentially expressed genes (DEGs) and Gene Ontology (GO) analysis, with a particular focus on myosin light chain kinase (MLCK). An MLCK inhibitor ML-7 was utilized in Pm-HOK co-culture model to assess its effects on monolayer permeability and ZO-1 expression.
RESULTS
HOK monolayer permeability was increased, and ZO-1 expression was decreased after co-culture (p < 0.05). Pm could survive in HOK cells. RNA-seq revealed MLCK was an upregulated common DEG. The expression of MLCK in the Pm-HOK co-culture model was upregulated. Inhibition of MLCK rescued the increased epithelial permeability, and ZO-1 expression was upregulated (p < 0.05).
CONCLUSION
MLCK may be involved in disrupting epithelial barrier function by Pm.
PubMed: 38720551
DOI: 10.1111/odi.14980 -
World Journal of Microbiology &... Oct 2023Dental biofilms represent a serious oral health problem playing a key role in the development of caries and other oral diseases. In the present work, we cloned and...
Dental biofilms represent a serious oral health problem playing a key role in the development of caries and other oral diseases. In the present work, we cloned and expressed in E. coli two glucanases, Prevotella melaninogenica mutanase (PmGH87) and Capnocytophaga ochracea dextranase (CoGH66), and characterized them biochemically and biophysically. Their three-dimensional structures were elucidated and discussed. Furthermore, we tested the capacity of the enzymes to hydrolyze mutan and dextran to prevent formation of Streptococcus mutans biofilms, as well as to degrade pre- formed biofilms in low and abundant sugar conditions. The percentage of residual biofilm was calculated for each treatment group in relation to the control, as well as the degree of synergism. Our results suggest that both PmGH87 and CoGH66 are capable of inhibiting biofilm formation grown under limited or abundant sucrose conditions. Degradation of pre-formed biofilms experiments reveal a time-dependent effect for the treatment with each enzyme alone. In addition, a synergistic and dose-dependent effects of the combined enzymatic treatment with the enzymes were observed. For instance, the highest biomass degradation was 95.5% after 30 min treatment for the biofilm grown in low sucrose concentration, and 93.8% after 2 h treatment for the biofilm grown in sugar abundant condition. Strong synergistic effects were observed, with calculated degree of synergism of 5.54 and 3.18, respectively and their structural basis was discussed. Jointly, these data can pave the ground for the development of biomedical applications of the enzymes for controlling growth and promoting degradation of established oral biofilms.
Topics: Escherichia coli; Prevotella melaninogenica; Biofilms; Sucrose
PubMed: 37882859
DOI: 10.1007/s11274-023-03804-z