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Antibiotics (Basel, Switzerland) Sep 2020Knowledge of microbial composition and antimicrobials' susceptibility to periodontal abscesses is vital for their successful treatment. The current study aims to provide...
Knowledge of microbial composition and antimicrobials' susceptibility to periodontal abscesses is vital for their successful treatment. The current study aims to provide a thorough overview of the clinical and microbial features of periodontal abscesses of the local community. The study was carried out at Rehman College of Dentistry, Peshawar, Pakistan between December 2019 to March 2020. Clinical measurements and microbial samples were collected from 45 subjects. Microbial samples were anaerobically cultured for the growth of selected bacterial species. E-test was used to assess the susceptibility of bacterial species grown from the patient samples to amoxicillin, azithromycin, metronidazole, and tetracycline. The majority of affected patients had preexisting chronic periodontitis. All abscesses clinically demonstrated bleeding on probing and suppuration. The periodontal abscess was most commonly associated with lower incisors and canines, followed by lower molars and then upper incisor and canine teeth. spp. (73%) was the most frequently detected species followed by (65%), (46%) and (24%). The detected clinical isolates of certain bacteria demonstrated resistance to all tested antibiotics except azithromycin. We conclude that spp., , and are closely associated with periodontal abscess. Bacterial species associated with periodontal abscess demonstrated some level of antimicrobial resistance to amoxicillin, metronidazole and tetracycline while antibiotic resistance to azithromycin could not be demonstrated.
PubMed: 33003527
DOI: 10.3390/antibiotics9100654 -
Journal of Gastrointestinal Oncology Oct 2022Colorectal cancer (CRC) is the fifth most diagnosed cancer in Sub-Saharan Africa. In Kenya, CRC incidence rates tripled from 1997 to 2017. In the Moi Teaching and...
BACKGROUND
Colorectal cancer (CRC) is the fifth most diagnosed cancer in Sub-Saharan Africa. In Kenya, CRC incidence rates tripled from 1997 to 2017. In the Moi Teaching and Referral Hospital, Moi University, there has been an increase in CRC cases, notably for younger patients. A suggested pathobiology for this increase is gut microbiome dysbiosis. Since, for the Kenyan CRC patient population, microbiome studies are rare, there is a need for a better understanding of how microbiome dysbiosis influences CRC epidemiology in Kenya. In this single-center study, the focus was on profiling the gut microbiome of Kenyan CRC patients and healthy volunteers and evaluating associations between microbiome profiles and the age of CRC patients.
METHODS
The gut mucosa-associated microbiome of 18 CRC patients and 18 healthy controls were determined by 16S rRNA sequencing and analyzed for alpha and beta diversity, differential abundance, and microbial metabolic profiling.
RESULTS
Alpha diversity metrics showed no significant differences, but beta diversity metrics showed dissimilarities in the microbial communities between CRC patients and healthy controls. The most underrepresented species in the CRC group were () and (), although () and were overrepresented (linear discriminant analysis, LDA score >2, P<0.05). Also, for CRC patients, significant metagenomic functional alterations were evident in microbial glutamate metabolic pathways (L-glutamate degradation VIII was enriched, and L-glutamate and L-glutamine biosynthesis were diminished) (P<0.05, log2 Fold Change >1). Moreover, the microbiome composition was different for patients under 40 years of age compared to older patients (LDA score >2, P<0.05).
CONCLUSIONS
Microbiome and microbial metabolic profiles of CRC patients are different from those of healthy individuals. CRC microbiome dysbiosis, particularly and depletion and glutamate metabolic alterations, are evident in Kenyan CRC patients.
PubMed: 36388691
DOI: 10.21037/jgo-22-116 -
Journal of Cystic Fibrosis : Official... Mar 2020Prevotella spp. are frequently identified in Cystic Fibrosis sputum. This study examined whether infection with Prevotella nigrescens, a frequently identified member of...
Prevotella spp. are frequently identified in Cystic Fibrosis sputum. This study examined whether infection with Prevotella nigrescens, a frequently identified member of this species, contributes to inflammation in CF bronchial epithelial cells through activation of TLR- and NF-κB signalling pathways. CFBE41o- cells were infected with either P.nigrescens or Pseudomonas aeruginosa and incubated under anaerobic conditions for 4h. P.nigrescens activated TLR2 signalling but not TLR4 signalling while P.aeruginosa activated TLR4 signalling with a lesser effect on TLR2. P.aeruginosa induced significant IκBα phosphorylation 10min post infection with a return to control levels by 30min post infection. A significant induction in nuclear p65 DNA binding was observed at 2h post infection. In contrast, infection with P.nigrescens induced phosphorylation of IκBα 120min post infection, with significant induction in nuclear p65 DNA binding at 4h post infection only. Cytokine gene and protein responses were lower for P.nigrescens compared to P.aeruginosa. This study demonstrates the ability of a clinical P.nigrescens isolate to provoke a delayed NF-κB(p65) driven response through induction in TLR2 signalling and activation of sustained levels of IKKα.
Topics: Bacteria, Anaerobic; Cells, Cultured; Cystic Fibrosis; Host-Pathogen Interactions; Humans; Inflammation; NF-kappa B; Prevotella nigrescens; Pseudomonas aeruginosa; Respiratory Mucosa; Signal Transduction; Toll-Like Receptor 2; Toll-Like Receptor 4; Transcription Factor RelA
PubMed: 31607634
DOI: 10.1016/j.jcf.2019.09.005 -
Frontiers in Oral Health 2021Periodontitis, a chronic inflammatory oral infection is the outcome of disturbances in the homeostasis of the oral biofilm microbiota. A number of studies have found...
Periodontitis, a chronic inflammatory oral infection is the outcome of disturbances in the homeostasis of the oral biofilm microbiota. A number of studies have found the occurrence of species in elevated levels in periodontitis compared to healthy subjects. Even though different aspects of as part of oral biofilm have been studied, biofilms formed by these species have not been characterized systematically. The objective of this study was to characterize biofilms formed by several species and further to assess biofilm inhibition and detachment of preformed biofilms. Biofilms were grown in 24-well plates containing brucella broth in anaerobic conditions for 3 days, and were quantified using crystal violet staining. Images of SYTO 9 Green fluorescent stained biofilms were captured using confocal microscopy. Biofilm inhibition and detachment by proteinase and DNase I was tested. The biochemical characterization included quantification of proteins and DNA in the biofilms and biofilm-supernatants. and showed highest biofilm formation. formed significantly higher amounts of biofilms than ( = 0.005) and ( = 0.0013). Inhibition of biofilm formation was significant only in the case of when treated with proteinase ( = 0.037), whereas with DNase I treatment, the inhibition was not significant ( = 0.531). Overall, proteinase was more effective in biofilm detachment than DNase I. Protein and DNA content were higher in biofilm than the supernatant with the highest amounts found in biofilm and supernatants. biofilms appeared to secrete large amounts of proteins extracellularly into the biofilm-supernatants. Significant differences among species to form biofilms may imply their variable abilities to get integrated into oral biofilm communities. Of the species that were able to grow as biofilms, DNase I and proteinase inhibited the biofilm growth or were able to cause biofilm detachment.
PubMed: 35048047
DOI: 10.3389/froh.2021.724194 -
Journal of Dental Research Sep 2021Cervical composites treating root carious and noncarious cervical lesions usually extend subgingivally. The subgingival margins of composites present poor plaque...
Cervical composites treating root carious and noncarious cervical lesions usually extend subgingivally. The subgingival margins of composites present poor plaque control, enhanced biofilm accumulation, and cause gingival irritation. A potential material to restore such lesions should combine agents that interfere with bacterial biofilm development and respond to acidic conditions. Here, we explore the use of new bioresponsive bifunctional dental composites against mature microcosm biofilms derived from subgingival plaque samples. The designed formulations contain 2 bioactive agents: dimethylaminohexadecyl methacrylate (DMAHDM) at 3 to 5 wt.% and 20 wt.% nanosized amorphous calcium phosphate (NACP) in a base resin. Composites with no DMAHDM and NACP were used as controls. The newly formulated 5% DMAHDM-20% NACP composite was analyzed by micro-Raman spectroscopy and transmission electron microscopy. The wettability and surface-free energy were also assessed. The inhibitory effect on the in vitro biofilm growth and the 16S rRNA gene sequencing of survival bacterial colonies derived from the composites were analyzed. Whole-biofilm metabolic activity, polysaccharide production, and live/dead images of the biofilm grown over the composites complement the microbiological assays. Overall, the designed formulations had higher contact angles with water and lower surface-free energy compared to the commercial control. The DMAHDM-NACP composites significantly inhibited the growth of total microorganisms, , , , and by 3 to 5-log ( < 0.001). For the colony isolates from control composites, the composition was typically dominated by the genera , , , , and , while and dominated the 5% DMAHDM-20% NACP composites. The DMAHDM-NACP composites contributed to over 80% of reduction in metabolic and polysaccharide activity. The suppression effect on plaque biofilms suggested that DMAHDM-NACP composites might be used as a bioactive material for cervical restorations. These results may propose an exciting path to prevent biofilm growth and improve dental composite restorations' life span.
Topics: Aggregatibacter actinomycetemcomitans; Anti-Bacterial Agents; Biofilms; Methacrylates; Nanocomposites; RNA, Ribosomal, 16S
PubMed: 34167373
DOI: 10.1177/00220345211018189 -
JDR Clinical and Translational Research Apr 2023Markers of poor oral health are associated with impaired cognition and higher risk of Alzheimer disease (AD) and thus may help predict AD.
INTRODUCTION
Markers of poor oral health are associated with impaired cognition and higher risk of Alzheimer disease (AD) and thus may help predict AD.
OBJECTIVES
The aim of this study was to evaluate the cross-sectional association between empirically derived groups of 19 IgG antibodies against periodontal microorganisms and cognition in middle-aged and older adults.
METHODS
The study population consisted of participants of the third National Health and Nutrition Examination Survey (NHANES III) (1988 to 1994), who were 60 y and older, among whom cognition and IgG antibodies against 19 periodontal microorganisms were measured ( = 5,162).
RESULTS
In multivariable quantile regression analyses, the Orange-Red (Prevotella melaninogenica, Prevotella intermedia, Prevotella nigrescens, Porphyromonas gingivalis) and Yellow-Orange (Staphylococcus intermedius, Streptococcus oralis, Streptococcus mutans, Fusobacterium nucleatum, Peptostreptococcus micros, Capnocytophaga ochracea) cluster scores were negatively associated with cognition. A 1-unit higher cluster score for the Orange-Red cluster was associated on average with a lower cognitive score (β for 30th quantile = -0.2640; 95% confidence interval [CI], -0.3431 to -0.1848). Similarly, a 1-unit higher score for the Yellow-Orange cluster was associated with a lower cognitive score (β for 30th quantile = -0.2445; 95% CI, -0.3517 to -0.1372).
CONCLUSION
Groups of IgG antibodies against periodontal microorganisms were associated with lower cognition among free living adults 60 years and older, who were previously undiagnosed with cognitive impairment. Though poor oral health precedes the development of dementia and AD, oral health information is currently not used, to our knowledge, to predict dementia or AD risk. Combining our findings with current algorithms may improve risk prediction for dementia and AD.
KNOWLEDGE TRANSLATION STATEMENT
IgG antibodies against periodontal microorganisms were associated with lower cognition among adults 60 years and older previously undiagnosed with cognitive impairment. Periodontal disease may predict cognition among older adults.
Topics: Cross-Sectional Studies; Dementia; Cognition; Immunoglobulin G; Periodontitis; Periodontium; Oral Health; Humans; Male; Female; Middle Aged; Aged; Aged, 80 and over
PubMed: 35139675
DOI: 10.1177/23800844211072784 -
Journal of Clinical Medicine Feb 2021This study aimed to evaluate the feasibility of diagnosing periodontitis via the identification of 18 bacterial species in mouth-rinse samples. Patients (n = 110) who...
This study aimed to evaluate the feasibility of diagnosing periodontitis via the identification of 18 bacterial species in mouth-rinse samples. Patients (n = 110) who underwent dental examinations in the Department of Periodontology at the Veterans Health Service Medical Center between 2018 and 2019 were included. They were divided into healthy and periodontitis groups. The overall number of bacteria, and those of 18 specific bacteria, were determined via real-time polymerase chain reaction in 92 mouth-rinse samples. Differences between groups were evaluated through logistic regression after adjusting for sex, age, and smoking history. There was a significant difference in the prevalence (healthy vs. periodontitis group) of (2.9% vs. 13.5%), (42.9% vs. 69.2%), and (80% vs. 2.7%). Levels of , , and were significantly associated with severe periodontitis. We demonstrated the feasibility of detecting periopathogenic bacteria in mouth-rinse samples obtained from patients with periodontitis. As we did not comprehensively assess all periopathogenic bacteria, further studies are required to assess the potential of oral-rinsing solutions to indicate oral infection risk and the need to improve oral hygiene, and to serve as a complementary method for periodontal disease diagnosis.
PubMed: 33671765
DOI: 10.3390/jcm10040891 -
Pharmaceuticals (Basel, Switzerland) Aug 2022This study aimed to investigate the chemical composition as well as the antibacterial, antiparasitic, and cytotoxic potentialities of the Brazilian root essential oil...
This study aimed to investigate the chemical composition as well as the antibacterial, antiparasitic, and cytotoxic potentialities of the Brazilian root essential oil (CZ-EO) In addition, CZ-EO cytotoxicity to LLCMK adherent epithelial cells was assessed. The major compounds identified in CZ-EO were khusimol (30.0 ± 0.3%), β-eudesmol (10.8 ± 0.3%), α-muurolene (6.0 ± 0.1%), and patchouli alcohol (5.6 ± 0.2%). CZ-EO displayed optimal antibacterial activity against , , , and , with Minimum Inhibitory Concentration (MIC) values between 22 and 62.5 µg/mL and Minimum Bactericidal Concentration (MBC) values between 22 and 400 µg/mL. CZ-EO was highly active against the promastigote and amastigote forms (IC = 7.20 and 16.21 µg/mL, respectively) and the trypomastigote form (IC = 11.2 µg/mL). Moreover, CZ-EO showed moderate cytotoxicity to LLCMK cells, with CC = 565.4 µg/mL. These results revealed an interesting in vitro selectivity of CZ-EO toward the promastigote and amastigote forms (Selectivity Index, SI = 78.5 and 34.8, respectively) and the trypomastigote form (SI = 50.5) compared to LLCMK cells. These results showed the promising potential of CZ-EO for developing new antimicrobial, antileishmanial, and antitrypanosomal drugs.
PubMed: 36015115
DOI: 10.3390/ph15080967 -
Microorganisms May 2020Oral bacteria possess the ability to form biofilms on solid surfaces. After the penetration of oral bacteria into the pulp, the contact between biofilms and pulp tissue...
Oral bacteria possess the ability to form biofilms on solid surfaces. After the penetration of oral bacteria into the pulp, the contact between biofilms and pulp tissue may result in pulpitis, pulp necrosis and/or periapical lesion. Depending on the environmental conditions and the availability of nutrients in the pulp chamber and root canals, mainly Gram-negative anaerobic microorganisms predominate and form the intracanal endodontic biofilm. The objective of the present study was to investigate the role of different substrates on biofilm formation as well as the separate and collective incorporation of six endodontic pathogens, namely and into a nine-species "basic biofilm". This biofilm was formed in vitro as a standard subgingival biofilm, comprising and The resulting endodontic-like biofilms were grown 64 h under the same conditions on hydroxyapatite and dentin discs. After harvesting the endodontic-like biofilms, the bacterial growth was determined using quantitative real-time PCR, were labeled using fluorescence in situ hybridization (FISH) and analyzed by confocal laser scanning microscopy (CLSM). The addition of six endodontic pathogens to the "basic biofilm" induced a decrease in the cell number of the "basic" species. Interestingly, counts increased in biofilms containing and respectively, both on hydroxyapatite and on dentin discs, whereas counts increased only on dentin discs by addition of . The growth of on hydroxyapatite discs and of and on dentin discs were significantly higher in the biofilm containing all species than in the "basic biofilm". Contrarily, the counts of , and on hydroxyapatite discs as well as counts of and on dentin discs decreased in the all-species biofilm. Overall, all bacterial species associated with endodontic infections were successfully incorporated into the standard multispecies biofilm model both on hydroxyapatite and dentin discs. Thus, future investigations on endodontic infections can rely on this newly established endodontic-like multispecies biofilm model.
PubMed: 32384777
DOI: 10.3390/microorganisms8050674 -
Archives of Microbiology Jan 2021Advanced combinatorial treatments of surgery, chemotherapy, and radiotherapy do not have any effect on the enhancement of a 5-year survival rate of oral squamous cell...
Advanced combinatorial treatments of surgery, chemotherapy, and radiotherapy do not have any effect on the enhancement of a 5-year survival rate of oral squamous cell carcinoma (OSCC). The discovery of early diagnostic non-invasive biomarkers is required to improve the survival rate of OSCC patients. Recently, it has been reported that oral microbiome has a significant contribution to the development of OSCC. Oral microbiome induces inflammatory response through the production of cytokines and chemokines that enhances tumor cell proliferation and survival. The study aims to develop saliva-based oral microbiome and cytokine biomarker panel that screen OSCC patients based on the level of the microbiome and cytokine differences. We compared the oral microbiome signatures and cytokine level in the saliva of OSCC patients and healthy individuals by 16S rRNA gene sequencing targeting the V3/V4 region using the MiSeq platform and cytokine assay, respectively. The higher abundance of Prevotella melaninogenica, Fusobacterium sp., Veillonella parvula, Porphyromonas endodontalis, Prevotella pallens, Dialister, Streptococcus anginosus, Prevotella nigrescens, Campylobacter ureolyticus, Prevotella nanceiensis, Peptostreptococcus anaerobius and significant elevation of IL-8, IL-6, TNF-α, GM-CSF, and IFN-γ in the saliva of patients having OSCC. Oncobacteria such as S. anginosus, V. parvula, P. endodontalis, and P. anaerobius may contribute to the development of OSCC by increasing inflammation via increased expression of inflammatory cytokines such as IL-6, IL-8, TNF-α, IFN-γ, and GM-CSF. These oncobacteria and cytokines panels could potentially be used as a non-invasive biomarker in clinical practice for more efficient screening and early detection of OSCC patients.
Topics: Adult; Bacteria; Bacterial Physiological Phenomena; Cytokines; Dysbiosis; Female; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Head and Neck Neoplasms; Humans; Inflammation; Male; Microbiota; Middle Aged; Mouth Neoplasms; RNA, Ribosomal, 16S; Saliva; Squamous Cell Carcinoma of Head and Neck
PubMed: 32783067
DOI: 10.1007/s00203-020-02011-w