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Antimicrobial Agents and Chemotherapy Sep 2021and species are fastidious organisms, representing the causative agents of ∼1% to 3% of cases of infective endocarditis (IE). Little is known about the optimal...
and species are fastidious organisms, representing the causative agents of ∼1% to 3% of cases of infective endocarditis (IE). Little is known about the optimal antibiotic treatment for these species, and daptomycin has been suggested as a therapeutic option. We describe the antimicrobial profiles of and IE isolates, investigate high-level daptomycin resistance (HLDR) development, and evaluate daptomycin activity in combination therapy. studies with 16 IE strains (6 Abiotrophia defectiva strains, 9 Granulicatella adiacens strains, and 1 G. elegans strain) were performed using microdilution to determine MICs and time-kill methodology to evaluate combination therapy. Daptomycin nonsusceptibility (DNS) (MIC ≥ 2 mg/liter) and HLDR (MIC ≥ 256 mg/liter) were based on existing Clinical and Laboratory Standards Institute (CLSI) breakpoints for viridans group streptococci. All isolates were susceptible to vancomycin: G. adiacens was more susceptible to penicillin and ampicillin than A. defectiva (22% versus 0% and 67% versus 33%) but less susceptible to ceftriaxone and daptomycin (56% versus 83% and 11% versus 50%). HLDR developed in both A. defectiva (33%) and (78%) after 24 h of exposure to daptomycin. Combination therapy did not prevent the development of daptomycin resistance with ampicillin (2/3 strains), gentamicin (2/3 strains), ceftriaxone (2/3 strains), or ceftaroline (2/3 strains). Once developed, HLDR was stable for a prolonged time (>3 weeks) in , whereas in A. defectiva, HLDR reversed to the baseline MIC at day 10. This study is the first to demonstrate rapid HLDR development in and species . Resistance was stable, and most combination therapies did not prevent it.
Topics: Abiotrophia; Anti-Bacterial Agents; Carnobacteriaceae; Daptomycin; Endocarditis, Bacterial; Humans
PubMed: 34252304
DOI: 10.1128/AAC.02522-20 -
Frontiers in Cellular and Infection... 2023White spot lesions (WSLs) have long been a noteworthy complication during orthodontic treatment. Recently, an increasing number of orthodontists have found that...
White spot lesions (WSLs) have long been a noteworthy complication during orthodontic treatment. Recently, an increasing number of orthodontists have found that adolescents undergoing orthodontic treatment with clear aligners are at a higher risk of developing WSLs. The oral microbiota and metabolites are considered the etiologic and regulatory factors of WSLs, but the specific impact of clear aligners on the oral microbiota and metabolites is unknown. This study investigated the differences in the salivary microbiome and metabolome between adolescents with and without WSLs treated with clear aligners. Fifty-five adolescents (aged 11-18) with Invisalign appliances, 27 with and 28 without WSLs, were included. Saliva samples were analyzed using 16S rRNA gene sequencing and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS); the data were further integrated for Spearman correlation analysis. The relative abundances of 14 taxa, including , , , , , , , , , and , were significantly higher in the WSL group than in the control group. Metabolomic analysis identified 27 potential biomarkers, and most were amino acids, including proline and glycine. The metabolites were implicated in 6 metabolic pathways, including alanine, aspartate and glutamate metabolism; glycine, serine and threonine metabolism; and aminoacyl-tRNA biosynthesis. There was a correlation between the salivary microbial and metabolomic datasets, reflecting the impact of clear aligners on the metabolic activity of the oral flora. A concordant increase in the levels of , , and some amino acids had predictive value for WSL development. In summary, when adolescents undergo long-term clear aligner therapy with poor oral hygiene habits, clear aligners can disrupt the balance of the oral microecosystem and lead to oral microbiota dysbiosis, thereby increasing the risk of developing WSLs. Our findings might contribute to the understanding of the pathogenesis of WSLs and provide candidate biomarkers for the diagnosis and treatment of WSLs associated with clear aligners.
Topics: Adolescent; Humans; RNA, Ribosomal, 16S; Chromatography, Liquid; Tandem Mass Spectrometry; Orthodontic Appliances, Removable; Microbiota; Bacteria; Metabolome; Amino Acids; Glycine; Dental Caries
PubMed: 37082715
DOI: 10.3389/fcimb.2023.1119616 -
Frontiers in Cellular and Infection... 2021Supragingival dental plaque samples were collected from 40 Swedish adolescents, including 20 with caries lesions (CAR) and 20 caries-free (CF). Fresh plaque samples were...
Supragingival dental plaque samples were collected from 40 Swedish adolescents, including 20 with caries lesions (CAR) and 20 caries-free (CF). Fresh plaque samples were subjected to an acid tolerance (AT) test where the proportion of bacteria resistant to an acid shock was evaluated through confocal microscopy and live/dead staining, and the metabolites produced were quantified by H Nuclear Magnetic Resonance (H NMR). In addition, DNA was extracted and the 16S rRNA gene was sequenced by Illumina sequencing, in order to characterize bacterial composition in the same samples. There were no significant differences in AT scores between CAR and CF individuals. However, 7 out of the 10 individuals with highest AT scores belonged to the CAR group. Regarding bacterial composition, , and were found at significantly higher levels in CAR individuals (p=0.0085, 0.026 and 0.04 respectively) and and at significantly higher levels in CF individuals (p=0.026 and 0.003). The caries pathogen was found at low frequencies and was absent in 60% of CAR individuals. Random-forest predictive models indicate that at least 4 bacterial species or 9 genera are needed to distinguish CAR from CF adolescents. The metabolomic profile obtained by NMR showed a significant clustering of organic acids with specific bacteria in CAR and/or high AT individuals, being the species with strongest associations. A significant clustering of ethanol and isopropanol with health-associated bacteria such as or was also found. Accordingly, several relationships involving these compounds like the Ethanol : Lactate or Succinate : Lactate ratios were significantly associated to acid tolerance and could be of predictive value for caries risk. We therefore propose that future caries risk studies would benefit from considering not only the use of multiple organisms as potential microbial biomarkers, but also their functional adaptation and metabolic output.
Topics: Actinobacteria; Adolescent; Dental Caries; Dental Plaque; Humans; Metabolomics; Microbiota; RNA, Ribosomal, 16S; Streptococcus mutans
PubMed: 34395316
DOI: 10.3389/fcimb.2021.716493 -
Medicine Mar 2017HIV-associated periodontal diseases (PD) could serve as a source of chronic inflammation. Here, we sought to characterize the oral microbial signatures of HIV+ and HIV-... (Observational Study)
Observational Study
HIV-associated periodontal diseases (PD) could serve as a source of chronic inflammation. Here, we sought to characterize the oral microbial signatures of HIV+ and HIV- individuals at different levels of PD severity.This cross-sectional study included both HIV+ and HIV- patients with varying degrees of PD. Two tooth, 2 cheek, and 1 saliva samples were obtained for microbiome analysis. Mothur/SILVADB were used to classify sequences. R/Bioconductor (Vegan, PhyloSeq, and DESeq2) was employed to assess overall microbiome structure differences and differential abundance of bacterial genera between groups. Polychromatic flow cytometry was used to assess immune activation in CD4 and CD8 cell populations.Around 250 cheek, tooth, and saliva samples from 50 participants (40 HIV+ and 10 HIV-) were included. Severity of PD was classified clinically as None/Mild (N), Moderate (M), and Severe (S) with 18 (36%), 16 (32%), and 16 (32%) participants in each category, respectively. Globally, ordination analysis demonstrated clustering by anatomic site (R2 = 0.25, P < 0.001). HIV status and PD severity showed a statistically significant impact on microbiome composition but only accounted for a combined 2% of variation. HIV+ samples were enriched in genera Abiotrophia, Neisseria, Kingella, and unclassified Neisseriaceae and depleted in Leptotrichia and Selenomonas. The Neisseria genus was consistently enriched in HIV+ participants regardless of sampling site and PD level. Immune markers were altered in HIV+ participants but did not show association with the oral microbiome.HIV-associated changes in oral microbiome result in subtle microbial signatures along different stages of PD that are common in independent oral anatomic sites.
Topics: Anti-Retroviral Agents; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cheek; Cross-Sectional Studies; Female; Flow Cytometry; HIV Infections; Humans; Male; Microbiota; Mouth; Periodontitis; RNA, Ribosomal, 16S; Saliva; Severity of Illness Index
PubMed: 28328799
DOI: 10.1097/MD.0000000000005821 -
Frontiers in Cellular and Infection... 2022This is the first study on gut microbiota (GM) in children affected by coronavirus disease 2019 (COVID-19). Stool samples from 88 patients with suspected severe acute...
This is the first study on gut microbiota (GM) in children affected by coronavirus disease 2019 (COVID-19). Stool samples from 88 patients with suspected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and 95 healthy subjects were collected (admission: 3-7 days, discharge) to study GM profile by 16S rRNA gene sequencing and relationship to disease severity. The study group was divided in COVID-19 (68), Non-COVID-19 (16), and MIS-C (multisystem inflammatory syndrome in children) (4). Correlations among GM ecology, predicted functions, multiple machine learning (ML) models, and inflammatory response were provided for COVID-19 and Non-COVID-19 cohorts. The GM of COVID-19 cohort resulted as dysbiotic, with the lowest α-diversity compared with Non-COVID-19 and CTRLs and by a specific β-diversity. Its profile appeared enriched in , , and and reduced in , , , , , , and , compared with CTRLs ( 0.05). All GM paired-comparisons disclosed comparable results through all time points. The comparison between COVID-19 and Non-COVID-19 cohorts highlighted a reduction of in the COVID-19 cohort ( < 0.05). The GM of MIS-C cohort was characterized by an increase of , , , , and and a decrease of , , , and , compared with CTRLs. Stratifying for disease severity, the GM associated to "moderate" COVID-19 was characterized by lower α-diversity compared with "mild" and "asymptomatic" and by a GM profile deprived in , , , and and enriched in , , , , , , and The ML models identified , , , , , , , , , , , , , , , , and as microbial markers of COVID-19. The KEGG ortholog (KO)-based prediction of GM functional profile highlighted 28 and 39 KO-associated pathways to COVID-19 and CTRLs, respectively. Finally, and correlated with proinflammatory cytokines regardless disease severity. Unlike adult GM profiles, was a specific marker of pediatric COVID-19 GM. The durable modification of patients' GM profile suggested a prompt GM quenching response to SARS-CoV-2 infection since the first symptoms. and reduced fatty acid and amino acid degradation were proposed as specific COVID-19 disease traits, possibly associated to restrained severity of SARS-CoV-2-infected children. Altogether, this evidence provides a characterization of the pediatric COVID-19-related GM.
Topics: Adult; Bacteroides; Bifidobacterium; COVID-19; Child; Clostridium; Feces; Gastrointestinal Microbiome; Humans; RNA, Ribosomal, 16S; SARS-CoV-2; Systemic Inflammatory Response Syndrome
PubMed: 35873161
DOI: 10.3389/fcimb.2022.908492 -
Frontiers in Oncology 2023Head and neck cancer (HNC) is the sixth most common type of cancer, with more than half a million new cases annually. This review focuses on the role of oral dysbiosis... (Review)
Review
Head and neck cancer (HNC) is the sixth most common type of cancer, with more than half a million new cases annually. This review focuses on the role of oral dysbiosis and HPV infection in HNCs, presenting the involved taxons, molecular effectors and pathways, as well as the HPV-associated particularities of genetic and epigenetic changes and of the tumor microenvironment occurred in different stages of tumor development. Oral dysbiosis is associated with the evolution of HNCs, through multiple mechanisms such as inflammation, genotoxins release, modulation of the innate and acquired immune response, carcinogens and anticarcinogens production, generation of oxidative stress, induction of mutations. Thus, novel microbiome-derived biomarkers and interventions could significantly contribute to achieving the desideratum of personalized management of oncologic patients, regarding both early diagnosis and treatment. The results reported by different studies are not always congruent regarding the variations in the abundance of different taxons in HNCs. However, there is a consistent reporting of a higher abundance of Gram-negative species such as , which are probably responsible of chronic inflammation and modulation of tumor microenvironment. is the dominant fungi found in oral carcinoma being also associated with shorter survival rate. Specific microbial signatures (e.g., and ) have been associated with later stages and larger tumor, suggesting their potential to be used as biomarkers for tumor stratification and prognosis. On the other hand, increased abundance of is associated with a reduced risk of HNC. Microbiome could also provide biomarkers for differentiating between oropharyngeal and hypopharyngeal cancers as well as between HPV-positive and HPV-negative tumors. Ongoing clinical trials aim to validate non-invasive tests for microbiome-derived biomarkers detection in oral and throat cancers, especially within high-risk populations. Oro-pharyngeal dysbiosis could also impact the HNCs therapy and associated side-effects of radiotherapy, chemotherapy, and immunotherapy. HPV-positive tumors harbor fewer mutations, as well as different DNA methylation pattern and tumor microenvironment. Therefore, elucidation of the molecular mechanisms by which oral microbiota and HPV infection influence the HNC initiation and progression, screening for HPV infection and vaccination against HPV, adopting a good oral hygiene, and preventing oral dysbiosis are important tools for advancing in the battle with this public health global challenge.
PubMed: 38179168
DOI: 10.3389/fonc.2023.1273516 -
Cancers May 2023The association between oral microbiota and cancer development has been a topic of intense research in recent years, with compelling evidence suggesting that the oral...
Exploring Connections between Oral Microbiota, Short-Chain Fatty Acids, and Specific Cancer Types: A Study of Oral Cancer, Head and Neck Cancer, Pancreatic Cancer, and Gastric Cancer.
The association between oral microbiota and cancer development has been a topic of intense research in recent years, with compelling evidence suggesting that the oral microbiome may play a significant role in cancer initiation and progression. However, the causal connections between the two remain a subject of debate, and the underlying mechanisms are not fully understood. In this case-control study, we aimed to identify common oral microbiota associated with several cancer types and investigate the potential mechanisms that may trigger immune responses and initiate cancer upon cytokine secretion. Saliva and blood samples were collected from 309 adult cancer patients and 745 healthy controls to analyze the oral microbiome and the mechanisms involved in cancer initiation. Machine learning techniques revealed that six bacterial genera were associated with cancer. The abundance of , , , and was reduced in the cancer group, while abundance of and enhanced. G protein-coupled receptor kinase, H+-transporting ATPase, and futalosine hydrolase were found significantly enriched in the cancer group. Total short-chain fatty acid (SCFAs) concentrations and free fatty acid receptor 2 (FFAR2) expression levels were greater in the control group when compared with the cancer group, while serum tumor necrosis factor alpha induced protein 8 (TNFAIP8), interleukin-6 (IL6), and signal transducer and activator of transcription 3 (STAT3) levels were higher in the cancer group when compared with the control group. These results suggested that the alterations in the composition of oral microbiota can contribute to a reduction in SCFAs and FFAR2 expression that may initiate an inflammatory response through the upregulation of TNFAIP8 and the IL-6/STAT3 pathway, which could ultimately increase the risk of cancer onset.
PubMed: 37296861
DOI: 10.3390/cancers15112898 -
Scientific Reports Apr 2021To explore the changes in oral flora in people with functional dyspepsia (FD). Unstimulated saliva was collected from 21 FD patients diagnosed according to the Rome IV...
To explore the changes in oral flora in people with functional dyspepsia (FD). Unstimulated saliva was collected from 21 FD patients diagnosed according to the Rome IV criteria and from 12 healthy controls (HCs) for 16SrRNA sequencing. The pH of saliva samples and community periodontal index (CPI) were tested. The prevalence of small intestinal bacterial overgrowth (SIBO) was obtained by the methane-and hydrogen-based breath test. At the phylum level, FD patients had a higher relative abundance of Spirochaetes and a lower relative abundance of Fusobacteria, TM7 and Proteobacteria than HCs (p < 0.01). In the saliva, Kingella and Abiotrophia genus levels showed significant changes between the FD and HC groups (p < 0.01). Salivary species level marker Intermedia was significantly different between FD and HC groups (p < 0.01). The oral pH of FD patients was higher than that of HCs (p < 0.01). The mean CPI of the FD group was 1.52 and that of the HC group was 0.17 (p < 0.01). Moreover, 71.4% of the FD group was positive for SIBO. The oral flora of FD patients was different from that of HCs. Spirochaetes, Kingella, Abiotrophia, and Intermedia may be diagnostic indicators of FD.
Topics: Adult; Case-Control Studies; Dyspepsia; Humans; Male; Microbiota; Middle Aged; Prevalence
PubMed: 33850203
DOI: 10.1038/s41598-021-87600-5 -
Journal of Clinical Microbiology Feb 2000The genus Abiotrophia represents a heterogeneous group of fastidious cocci that show a dependence on pyridoxal hydrochloride analogs for growth. The genetic...
The genus Abiotrophia represents a heterogeneous group of fastidious cocci that show a dependence on pyridoxal hydrochloride analogs for growth. The genetic heterogeneity in the genus Abiotrophia was examined by DNA-DNA hybridization, PCR assay of genomic DNA sequences, and restriction fragment length polymorphism and sequence homology analyses of the PCR-amplified 16S rRNA gene. Nine type or reference strains of Abiotrophia defectiva, Abiotrophia adiacens, and Abiotrophia elegans and 36 oral Abiotrophia isolates including the ones presumptively identified as Gemella morbillorum by the rapid ID32 STREP system were divided into four groups: A. defectiva (genotype 1), A. adiacens (genotype 2), A. elegans (genotype 4), and a fourth species (genotype 3) which we propose be named Abiotrophia para-adiacens sp. nov. A PCR assay specific for detection and identification of the novel Abiotrophia species was developed. A. para-adiacens generally produced beta-glucosidase but did not produce alpha- or beta-galactosidase or arginine dihydrolase, did not ferment, trehalose, pullulan, or tagatose, and was serotype IV, V, or VI. Thus, it was distinguished phenotypically from A. adiacens, A. elegans, and A. defectiva as well as, apparently, from the recently described species Abiotrophia balaenopterae sp. nov., which produces arginine dihydrolase and which ferments pullulan but not sucrose (P. A. Lawson et al., Int. J. Syst. Bacteriol. 49:503-506, 1999). Strain ATCC 27527, currently listed as G. morbillorum, was a member of the species A. para-adiacens.
Topics: Bacteremia; Bacterial Typing Techniques; DNA, Bacterial; Endocarditis, Bacterial; Genes, rRNA; Genetic Heterogeneity; Genetic Variation; Gram-Positive Bacterial Infections; Humans; Molecular Sequence Data; Nucleic Acid Hybridization; Phenotype; Phylogeny; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid; Streptococcaceae
PubMed: 10655334
DOI: 10.1128/JCM.38.2.492-498.2000 -
BMJ Case Reports Dec 2014A previously healthy 27-year-old Jamaican man presented to the University Hospital of the West Indies with recurrent joint pain, remitting and relapsing fever, and...
A previously healthy 27-year-old Jamaican man presented to the University Hospital of the West Indies with recurrent joint pain, remitting and relapsing fever, and shortness of breath. He was subsequently found to have Abiotrophia defectiva endocarditis. This was the first time this organism had been isolated at our institution. Despite culture directed antibiotics, his clinical course was quite severe with mitral regurgitation and congestive cardiac failure requiring mitral valve replacement. He recovered well postoperatively and is currently being followed at our outpatient cardiology clinic. This report highlights the severe presentation and often poor outcome associated with A. defectiva endocarditis and stresses that the outcome may be improved by early and appropriate surgical intervention.
Topics: Abiotrophia; Adult; Anti-Bacterial Agents; Endocarditis, Bacterial; Gram-Positive Bacterial Infections; Heart Failure; Heart Valve Prosthesis Implantation; Humans; Male; Mitral Valve; Mitral Valve Insufficiency
PubMed: 25519863
DOI: 10.1136/bcr-2014-207361