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Microbial Pathogenesis Mar 2023This study is an investigation of anaerobic nitrite and fumarate reduction/respiration abilities of two characterised Prevotella species namely Prevotella nigrescens...
OBJECTIVE
This study is an investigation of anaerobic nitrite and fumarate reduction/respiration abilities of two characterised Prevotella species namely Prevotella nigrescens (SS6B) and Prevotella buccae (GS6B) isolated from the periodontal pockets of chronic periodontitis (ChP) patients.
METHODS
Isolation and identification of the periodontal bacteria from 20 patients showing clinical symptoms of ChP. Characterisation of anaerobic nitrite and fumarate reduction was done in P. nigrescens (SS6B) and P. buccae (GS6B) using reduction assays, inhibition assays with use of specific inhibitors, growth assays and enzyme activity assays. Degenerate PCR was used to detect and amplify nitrite reductase (nrfA) and fumarate reductase (frdA) gene sequences in these Prevotella isolates. In addition, molecular and in silico analysis of the amplified anaerobic reductase gene sequences was performed using NCBI conserved domain analysis, Interpro database and MegaX.
RESULTS
We provided experimental evidence for presence of active nitrite and fumarate reductase activities through enzyme activity, reduction, inhibitor and growth assays. Moreover, we were able to detect presence of 505 bps nrfA gene fragment and 400 bps frdA gene fragment in these Prevotella spp. These fragments show similarity to multiheme ammonia forming cytochrome c nitrite reductases and fumarate reductases flavoprotein subunit, respectively.
CONCLUSION
Anaerobic nitrite and fumarate respiration abilities in P. nigrescens and P. buccae isolates appear to be important for detoxification process and growth, respectively.
Topics: Humans; Chronic Periodontitis; Prevotella nigrescens; Nitrites; Succinate Dehydrogenase
PubMed: 36739100
DOI: 10.1016/j.micpath.2023.106022 -
Biologia Futura Dec 2021More than 6 billion bacteria and other microorganisms live in the adult oral cavity. As a result of any deleterious effect on this community, some microorganisms will...
More than 6 billion bacteria and other microorganisms live in the adult oral cavity. As a result of any deleterious effect on this community, some microorganisms will survive better than others, which may trigger pathogenic processes like caries, halitosis, gingivitis or periodontitis. Oral dysbiosis is among the most frequent human health hazards globally. Quality of life of patients deteriorates notably, while treatments are often unpleasant, expensive and irreversible, e.g. tooth loss. In the experiments reported here, we investigated the individual interactions between 8 pathogenic and 8 probiotic strains and a commercially available probiotic product. Almost all pathogens, namely Fusobacterium nucleatum, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Streptococcus mutans, Streptococcus oralis, Streptococcus gordonii, Enterococcus faecalis and Prevotella buccae are pathogens frequently occurring in the oral cavity. The used probiotic strains were Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus delbrueckii, Bifidobacterium thermophilum and two Streptococcus dentisani isolates. Using a modified agar diffusion method, we investigated capability of the probiotic bacteria to prevent the growth of the pathogenic ones in order to identify candidates for future therapeutic treatments. The results indicated successful bacteriocin production, i.e. growth inhibition, against every pathogenic bacterium by at least 5 probiotic strains.
Topics: Antibiosis; Humans; Mouth; Periodontitis; Probiotics; Virulence Factors
PubMed: 34554489
DOI: 10.1007/s42977-021-00091-3 -
Cureus May 2023Necrotizing infections of deep neck spaces are a group of life-threatening infectious diseases acquired through trauma or as a descending infection from an odontogenic...
Necrotizing infections of deep neck spaces are a group of life-threatening infectious diseases acquired through trauma or as a descending infection from an odontogenic source. The isolation of pathogens is unusual because of the anaerobic nature of the infection; however, one way to achieve this is through the use of automated microbiological methods like matrix-assisted laser desorption/ionization and time-of-flight (MALDI-TOF) following standard microbiology protocols for analyzing samples from potential anaerobic infections. We present a case of a patient without risk factors for descending necrotizing mediastinitis with isolation managed at the intensive care unit with a multidisciplinary team. We present our approach and how we successfully treat this complicated infection.
PubMed: 37398802
DOI: 10.7759/cureus.39703 -
Archive of Clinical Cases 2023is a gram-negative obligate anaerobe mainly associated with infections of odontogenic origin. Non-oral monomicrobial infection by these obligate anaerobic bacteria is...
is a gram-negative obligate anaerobe mainly associated with infections of odontogenic origin. Non-oral monomicrobial infection by these obligate anaerobic bacteria is rare. Only a few cases of monomicrobial non-oral infections by have been reported in the literature. We are reporting a case of unilateral complicated pleural empyema in a patient with bronchial asthma infected by . Pleural fluid aerobic culture and blood culture reports were sterile. No acid-fast bacilli were detected by Acid Fast Bacilli (AFB) staining, and cartridge-based nucleic acid assay test (CBNAAT) reports were negative for . The isolate, was found susceptible to Metronidazole (MIC = 3 μg/ml) and resistant to Clindamycin (MIC = 256 μg/ml). In view of rising trends of antimicrobial resistance among anaerobes, it is recommended to perform anaerobic culture and sensitivity testing in clinically suspected cases of pleuropulmonary infection for appropriate diagnosis and optimal patient management. Clindamycin should be used with caution for empiric treatment.
PubMed: 38026109
DOI: 10.22551/2023.41.1004.10263 -
Science (New York, N.Y.) Apr 2023Type VI CRISPR-Cas systems use RNA-guided ribonuclease (RNase) Cas13 to defend bacteria against viruses, and some of these systems encode putative membrane proteins that...
Type VI CRISPR-Cas systems use RNA-guided ribonuclease (RNase) Cas13 to defend bacteria against viruses, and some of these systems encode putative membrane proteins that have unclear roles in Cas13-mediated defense. We show that Csx28, of type VI-B2 systems, is a transmembrane protein that assists to slow cellular metabolism upon viral infection, increasing antiviral defense. High-resolution cryo-electron microscopy reveals that Csx28 forms an octameric pore-like structure. These Csx28 pores localize to the inner membrane in vivo. Csx28's antiviral activity in vivo requires sequence-specific cleavage of viral messenger RNAs by Cas13b, which subsequently results in membrane depolarization, slowed metabolism, and inhibition of sustained viral infection. Our work suggests a mechanism by which Csx28 acts as a downstream, Cas13b-dependent effector protein that uses membrane perturbation as an antiviral defense strategy.
Topics: CRISPR-Cas Systems; Cryoelectron Microscopy; Membrane Proteins; RNA, Viral; Bacterial Proteins; Endodeoxyribonucleases; CRISPR-Associated Proteins; RNA Cleavage; Bacteriophages; Bacteriophage lambda; Escherichia coli; Prevotella
PubMed: 37104586
DOI: 10.1126/science.abm1184 -
The Journal of Antimicrobial... Apr 2024Recently, reports on antimicrobial-resistant Bacteroides and Prevotella isolates have increased in the Netherlands. This urged the need for a surveillance study on the...
Antimicrobial susceptibility profile of clinically relevant Bacteroides, Phocaeicola, Parabacteroides and Prevotella species, isolated by eight laboratories in the Netherlands.
OBJECTIVES
Recently, reports on antimicrobial-resistant Bacteroides and Prevotella isolates have increased in the Netherlands. This urged the need for a surveillance study on the antimicrobial susceptibility profile of Bacteroides, Phocaeicola, Parabacteroides and Prevotella isolates consecutively isolated from human clinical specimens at eight different Dutch laboratories.
METHODS
Each laboratory collected 20-25 Bacteroides (including Phocaeicola and Parabacteroides) and 10-15 Prevotella isolates for 3 months. At the national reference laboratory, the MICs of amoxicillin, amoxicillin/clavulanic acid, piperacillin/tazobactam, meropenem, imipenem, metronidazole, clindamycin, tetracycline and moxifloxacin were determined using agar dilution. Isolates with a high MIC of metronidazole or a carbapenem, or harbouring cfiA, were subjected to WGS.
RESULTS
Bacteroides thetaiotaomicron/faecis isolates had the highest MIC90 values, whereas Bacteroides fragilis had the lowest MIC90 values for amoxicillin/clavulanic acid, piperacillin/tazobactam, meropenem, imipenem and moxifloxacin. The antimicrobial profiles of the different Prevotella species were similar, except for amoxicillin, for which the MIC50 ranged from 0.125 to 16 mg/L for Prevotella bivia and Prevotella buccae, respectively. Three isolates with high metronidazole MICs were sequenced, of which one Bacteroides thetaiotaomicron isolate harboured a plasmid-located nimE gene and a Prevotella melaninogenica isolate harboured a nimA gene chromosomally.Five Bacteroides isolates harboured a cfiA gene and three had an IS element upstream, resulting in high MICs of carbapenems. The other two isolates harboured no IS element upstream of the cfiA gene and had low MICs of carbapenems.
CONCLUSIONS
Variations in resistance between species were observed. To combat emerging resistance in anaerobes, monitoring resistance and conducting surveillance are essential.
Topics: Humans; Meropenem; Moxifloxacin; Netherlands; Metronidazole; Laboratories; Bacteroides; Anti-Bacterial Agents; Carbapenems; Bacteroides fragilis; Imipenem; Anti-Infective Agents; Microbial Sensitivity Tests; Piperacillin; Tazobactam; Prevotella; Amoxicillin; Clavulanic Acid
PubMed: 38394460
DOI: 10.1093/jac/dkae043 -
Oral Diseases Nov 2023To investigate the association between Alzheimer's disease (AD) and periodontitis in the aspects of periodontal status, serological markers, and oral microbiome.
OBJECTIVE
To investigate the association between Alzheimer's disease (AD) and periodontitis in the aspects of periodontal status, serological markers, and oral microbiome.
MATERIALS AND METHODS
Twenty AD and 20 healthy subjects were enrolled in this age- and gender-matched case-control study. Clinical periodontal parameters and serum biomarkers, including amyloid β (Aβ ), Tau, phosphorylated Tau (pTau), triglyceride, pro-inflammatory cytokines, and anti-Porphyromonas gingivalis lipopolysaccharide (LPS) antibody were examined. The saliva samples were analyzed for oral microbiome composition.
RESULTS
Alzheimer's disease patients with Clinical Dementia Rating (CDR) ≥1 exhibited significantly more clinical attachment loss (CAL) than those with lower CDR. The levels of serum Tau protein, hsCRP and anti-P. gingivalis LPS antibody were markedly elevated in the AD group compared with the control group. Serum pTau protein level was positively correlated with anti-P. gingivalis LPS antibody titer. Moreover, the increased abundances of Capnocytophaga sp ora clone DZ074, Eubacterium infirmum, Prevotella buccae, and Selenomonas artemidis were detected in the AD group. Interestingly, serum levels of Aβ pTau, and anti-P. gingivalis LPS antibody were strongly related to the gene upregulation in human pathogen septicemia.
CONCLUSIONS
Our study suggested the association of periodontal infection and oral microbiome with AD. Further large-scale studies with longitudinal follow-up are warranted.
Topics: Humans; Alzheimer Disease; Amyloid beta-Peptides; Case-Control Studies; Lipopolysaccharides; Periodontitis
PubMed: 35950713
DOI: 10.1111/odi.14348 -
Anaerobe Feb 2020Mediastinitis is a well-known complication of open-heart surgery. Strictly anaerobic bacteria are rarely found in this condition, unlike in descending mediastinitis. We...
Mediastinitis is a well-known complication of open-heart surgery. Strictly anaerobic bacteria are rarely found in this condition, unlike in descending mediastinitis. We report the case of a mediastinitis due to Prevotella buccae after surgical replacement of the aortic valve and triple coronary artery bypass in an immunocompetent 76 year-old man. The bacteria were found in pure culture on blood samples and surgical samples. This case emphasizes the need to perform anaerobic cultures in case of sternal wound infection after open-heart surgery.
Topics: Aged; Anti-Bacterial Agents; Bacterial Infections; Biomarkers; Cardiac Surgical Procedures; Humans; Male; Mediastinitis; Postoperative Complications; Prevotella
PubMed: 31494261
DOI: 10.1016/j.anaerobe.2019.102097 -
BMJ Case Reports Jan 2022Torticollis in children can be a sign of a potentially dangerous disease; the correct diagnosis is not always obvious on history and physical examination. The use of...
Torticollis in children can be a sign of a potentially dangerous disease; the correct diagnosis is not always obvious on history and physical examination. The use of point-of-care ultrasound (POCUS) helps to limit the differential diagnosis and direct appropriate further laboratory and radiology-performed evaluation. We present a case of a 10-year-old child whose deep neck infection (DNI) was timely diagnosed in the paediatric emergency department by early use of POCUS and drained under POCUS guidance after admission to the hospital. The culture from the fluid grew This case demonstrates that DNIs occur in children with acute acquired torticollis, even without fever and demonstrates the importance of early use of POCUS in cases where DNI is a potential diagnosis. Moreover, this case emphasises the importance of microbiological identification of DNIs that can be the key to successful treatment.
Topics: Child; Emergency Service, Hospital; Humans; Neck; Point-of-Care Systems; Torticollis; Ultrasonography
PubMed: 34992062
DOI: 10.1136/bcr-2021-244331 -
Orthodontics & Craniofacial Research Feb 2024To investigate the salivary bacterial communities during the first 6-month orthodontic treatment with Clear Aligners (CA) and Fixed Appliances (FA), and its correlation...
OBJECTIVE
To investigate the salivary bacterial communities during the first 6-month orthodontic treatment with Clear Aligners (CA) and Fixed Appliances (FA), and its correlation with clinical periodontal parameters.
MATERIALS AND METHODS
Saliva and periodontal parameters were sampled from individuals wearing CA or FA before treatment (T0), and after 3- (T3) and 6-month (T6) treatments. Salivary bacterial communities characterized based on the 16S rRNA V3-V4 region were compared between FA and CA and correlated with clinical periodontal parameters.
RESULTS
Probing Depth (PD) significantly increased at T6 in the FA group versus T0, whereas it remained stable in the CA group. The Shannon and Pielou indices were significantly higher in the FA group and significantly positively correlated with periodontal inflammation parameters. β-diversity analysis revealed distinct communities between the FA group and CA group at T6. The relative abundances of 3 genera and 15 species were significantly higher in the FA group. Among the above appliance-type related taxa, bacterial genera Selenomonas, Stomatobaculum, Olsenella and Faecalicoccus and bacterial species Selenomonas_sputigena, Dialister_invisus, Olsenella_profus, Prevotella_buccae, Cryptobacterium_curtum and Clostridium_spiroforme were significantly positively associated with periodontal parameters.
CONCLUSIONS
Orthodontic treatments trigger appliance-related salivary bacterial communities, highlighting the importance of developing appliance-orientated periodontal strategies during orthodontic treatments. Salivary bacterial communities harboured by patients wearing FA possess higher bacterial parameters which were associated with increasing PD, PI and Gingival Index.
Topics: Humans; RNA, Ribosomal, 16S; Orthodontic Appliances; Orthodontic Appliances, Fixed; Saliva; Microbiota
PubMed: 37985447
DOI: 10.1111/ocr.12733