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Antibiotics (Basel, Switzerland) Sep 2023Antifungal agents are widely used to specifically eliminate infections by fungal pathogens. However, the specificity of antifungal agents has been challenged by a few...
Antifungal agents are widely used to specifically eliminate infections by fungal pathogens. However, the specificity of antifungal agents has been challenged by a few studies demonstrating antibacterial inhibitory effects against and species. Here, we evaluated for the first time the potential effect of fluconazole, the most clinically used antifungal agent, on a human oral microbiota biofilm model. The results showed that biofilm viability on blood and mitis salivarius agar media was increased over time in the presence of fluconazole at clinically relevant concentrations, despite a reduction in biomass. Targeted PCR revealed a higher abundance of , and spp. in the fluconazole-treated samples compared to the control, while was reduced and spp were not significantly affected. Further, we tested the potential impact of fluconazole using single-species models. Our results, using and luciferase reporters, showed that planktonic growth was not significantly affected by fluconazole, whereas for , planktonic growth, but not biofilm viability, was inhibited at the highest concentration. Fluconazole's effects on biofilm biomass were concentration and time dependent. Exposure for 48 h to the highest concentration of fluconazole was associated with biofilms with the most increased biomass. Potential growth inhibitory effects were further tested using four non-streptococcal species. Among these, the planktonic growth of both and was inhibited by fluconazole. The data indicate bacterial responses to fluconazole that extend to a broader range of bacterial species than previously anticipated from the literature, with the potential to disturb biofilm communities.
PubMed: 37760729
DOI: 10.3390/antibiotics12091433 -
Antibiotics (Basel, Switzerland) Jan 2021We asked whether transient in the oral environment synergistically interacts with orally associated bacterial species such as , , , , , and (six-species control...
We asked whether transient in the oral environment synergistically interacts with orally associated bacterial species such as , , , , , and (six-species control biofilm 6S). For this purpose, four modified biofilms with seven species that contain either the wild type strain of the genotype (USA300-MRSA WT), its isogenic mutant with MSCRAMM deficiency (USA300-MRSA ΔMSCRAMM), a methicillin-sensitive (ST72-MSSA-) or a methicillin-resistant (USA800-MRSA) grown on hydroxyapatite disks were examined. Culture analyses, confocal-laser-scanning microscopy and proteome analyses were performed. strains affected the amount of supragingival biofilm-associated species differently. The deletion of MSCRAMM genes disrupted the growth of and the distribution of and within the biofilms. In addition, caused shifts in the number of detectable proteins of other species in the 6S biofilm. (USA300-MRSA WT), aggregated together with early colonizers such as and streptococci, influenced the number of secondary colonizers such as and was involved in structuring the biofilm architecture that triggered the change from a homeostatic biofilm to a dysbiotic biofilm to the development of oral diseases.
PubMed: 33530340
DOI: 10.3390/antibiotics10020116 -
International Journal of Obesity (2005) Jan 2020Mother-to-newborn transmission of obesity-associated microbiota may be modified by birth mode (vaginal vs. Cesarean delivery). Prospective data to test this hypothesis...
BACKGROUND
Mother-to-newborn transmission of obesity-associated microbiota may be modified by birth mode (vaginal vs. Cesarean delivery). Prospective data to test this hypothesis are still sparse.
OBJECTIVE
To examine prospective associations of maternal pre-pregnancy BMI and gestational weight gain with the infant gut microbiome by birth-mode strata.
SUBJECTS/METHODS
In 335 mother-infant pairs in the New Hampshire Birth Cohort, we ascertained data from questionnaires and medical records, and generated microbiome data from 6-week-old infants' stool using Illumina 16s rRNA gene sequencing (V4-V5 region). Analyses were stratified by birth mode and conducted before and after adjusting for potential confounders, which included maternal age, education, parity, and Mediterranean diet score.
RESULTS
Among 335 mothers, 56% had normal pre-pregnancy BMI ( < 25, referent), 27% were overweight (BMI 25-30), and 18% obese (BMI > 30). Among the 312 mothers with weight gain data, 10% had inadequate weight gain, 30% adequate (referent), and 60% excess. Birth mode modified associations of pre-pregnancy BMI with several genera, including the most abundant genus, Bacteroides (P for interaction = 0.05). In the vaginal-delivery group, maternal overweight or obesity was associated with higher infant gut microbiome diversity and higher relative abundance of 15 operational taxonomic units (OTUs), including overrepresentation of Bacteroides fragilis, Escherichia coli, Veillonella dispar, and OTUs in the genera Staphylococcus and Enterococcus. In the Cesarean-delivered group, there were no significant associations of pre-pregnancy BMI with infant microbiome (alpha) diversity or OTUs. Gestational weight gain was not associated with differential relative abundance of infant gut microbial OTUs or with measures of microbial diversity in infants delivered vaginally or by Cesarean section.
CONCLUSIONS
Among vaginally-delivered infants, maternal overweight and obesity was associated with altered infant gut microbiome composition and higher diversity. These associations were not observed in Cesarean-delivered infants, whose microbiome development differs from vaginally-delivered infants. Our study provides additional evidence of birth-mode dependent associations of maternal body weight status with the infant gut microbiota. The role of these associations in mediating the intergenerational cycle of obesity warrants further examination.
Topics: Adult; Bacteria; Body Mass Index; Body Weight; Delivery, Obstetric; Feces; Female; Gastrointestinal Microbiome; Gestational Weight Gain; Humans; Infant; Male; Pregnancy; Prospective Studies
PubMed: 30765892
DOI: 10.1038/s41366-018-0273-0 -
PloS One 2016Live attenuated influenza vaccine (LAIV) has demonstrated varying levels of efficacy against seasonal influenza; however, LAIV may be used as a tool to measure...
Live attenuated influenza vaccine (LAIV) has demonstrated varying levels of efficacy against seasonal influenza; however, LAIV may be used as a tool to measure interactions between the human microbiome and a live, replicating virus. To increase our knowledge of this interaction, we measured changes to the nasal microbiome in subjects who received LAIV to determine if associations between influenza-specific IgA production and the nasal microbiome exist after immunization with a live virus vaccine. The anterior nares of 47 healthy subjects were swabbed pre- (Day 0) and post- (Days 7 and 28) LAIV administration, and nasal washes were conducted on Days 0 and 28. We performed next-generation sequencing on amplified 16s rRNA genes and measured mucosal influenza-specific IgA titers via enzyme-linked immunosorbent assay (ELISA). A significant increase in alpha diversity was identified (Observed, CHAO, and ACE) between Days 7 vs 0 (p-values = 0.017, 0.005, 0.005, respectively) and between Days 28 vs 0 (p-values = 0.054, 0.030, 0.050, respectively). Several significant associations between the presence of different microbial species, including Lactobacillus helveticus, Prevotella melaninogenica, Streptococcus infantis, Veillonella dispar, and Bacteroides ovatus, and influenza-specific H1 and H3 IgA antibody response were demonstrated. These data suggest that LAIV alters the nasal microbiome, allowing several less-abundant OTUs to establish a community niche. Additionally, specific alterations in the nasal microbiome are significantly associated with variations in influenza-specific IgA antibody production and could be clinically relevant.
Topics: Adolescent; Adult; Antibodies, Viral; Bacteria; Female; Hemagglutinin Glycoproteins, Influenza Virus; Humans; Immunoglobulin A; Influenza A virus; Influenza Vaccines; Influenza, Human; Male; Microbiota; Nasal Cavity; Vaccines, Attenuated; Young Adult
PubMed: 27643883
DOI: 10.1371/journal.pone.0162803 -
PloS One 2016Methanethiol (methyl mercaptan) is an important contributor to oral malodour and periodontal tissue destruction. Porphyromonas gingivalis, Prevotella intermedia and...
Methanethiol (methyl mercaptan) is an important contributor to oral malodour and periodontal tissue destruction. Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum are key oral microbial species that produce methanethiol via methionine gamma lyase (mgl) activity. The aim of this study was to compare an mgl knockout strain of P. gingivalis with its wild type using a 10-species biofilm co-culture model with oral keratinocytes and its effect on biofilm composition and inflammatory cytokine production. A P. gingivalis mgl knockout strain was constructed using insertion mutagenesis from wild type W50 with gas chromatographic head space analysis confirming lack of methanethiol production. 10-species biofilms consisting of Streptococcus mitis, Streptococcus oralis, Streptococcus intermedius, Fusobacterium nucleatum ssp polymorphum, Fusobacterium nucleatum ssp vincentii, Veillonella dispar, Actinomyces naeslundii, Prevotella intermedia and Aggregatibacter actinomycetemcomitans with either the wild type or mutant P. gingivalis were grown on Thermanox cover slips and used to stimulate oral keratinocytes (OKF6-TERT2), under anaerobic conditions for 4 and 24 hours. Biofilms were analysed by quantitative PCR with SYBR Green for changes in microbial ecology. Keratinocyte culture supernatants were analysed using a multiplex bead immunoassay for cytokines. Significant population differences were observed between mutant and wild type biofilms; V. dispar proportions increased (p<0.001), whilst A. naeslundii (p<0.01) and Streptococcus spp. (p<0.05) decreased in mutant biofilms. Keratinocytes produced less IL-8, IL-6 and IL-1α when stimulated with the mutant biofilms compared to wild type. Lack of mgl in P. gingivalis has been shown to affect microbial ecology in vitro, giving rise to a markedly different biofilm composition, with a more pro-inflammatory cytokine response from the keratinocytes observed. A possible role for methanethiol in biofilm formation and cytokine response with subsequent effects on oral malodor and periodontitis is suggested.
Topics: Adhesins, Bacterial; Biofilms; Carbon-Sulfur Lyases; Cell Line; Cysteine Endopeptidases; Cytokines; Gene Knockout Techniques; Gingipain Cysteine Endopeptidases; Humans; Inflammation; Keratinocytes; Mouth; Porphyromonas gingivalis; Sulfur
PubMed: 28033374
DOI: 10.1371/journal.pone.0169157 -
Free Radical Biology & Medicine May 2018Nitric oxide (NO) can be generated endogenously via NO synthases or via the diet following the action of symbiotic nitrate-reducing bacteria in the oral cavity. Given...
Nitric oxide (NO) can be generated endogenously via NO synthases or via the diet following the action of symbiotic nitrate-reducing bacteria in the oral cavity. Given the important role of NO in smooth muscle control there is an intriguing suggestion that cardiovascular homeostasis may be intertwined with the presence of these bacteria. Here, we measured the abundance of nitrate-reducing bacteria in the oral cavity of 25 healthy humans using 16S rRNA sequencing and observed, for 3.5 h, the physiological responses to dietary nitrate ingestion via measurement of blood pressure, and salivary and plasma NO metabolites. We identified 7 species of bacteria previously known to contribute to nitrate-reduction, the most prevalent of which were Prevotella melaninogenica and Veillonella dispar. Following dietary nitrate supplementation, blood pressure was reduced and salivary and plasma nitrate and nitrite increased substantially. We found that the abundance of nitrate-reducing bacteria was associated with the generation of salivary nitrite but not with any other measured variable. To examine the impact of bacterial abundance on pharmacokinetics we also categorised our participants into two groups; those with a higher abundance of nitrate reducing bacteria (> 50%), and those with a lower abundance (< 50%). Salivary nitrite production was lower in participants with lower abundance of bacteria and these individuals also exhibited slower salivary nitrite pharmacokinetics. We therefore show that the rate of nitrate to nitrite reduction in the oral cavity is associated with the abundance of nitrate-reducing bacteria. Nevertheless, higher abundance of these bacteria did not result in an exaggerated plasma nitrite response, the best known marker of NO bioavailability. These data from healthy young adults suggest that the abundance of oral nitrate-reducing bacteria does not influence the generation of NO through the diet, at least when the host has a functional minimum threshold of these microorganisms.
Topics: Adult; Bacteria; Cross-Sectional Studies; Female; Humans; Male; Microbiota; Mouth; Nitrates; Nitric Oxide; Nitrites; Saliva
PubMed: 29550328
DOI: 10.1016/j.freeradbiomed.2018.03.023 -
Clinical Oral Implants Research Jul 2016Staphylococcus spp. are postulated to play a role in peri-implantitis. This study aimed to develop a "submucosal" in vitro biofilm model, by integrating two...
OBJECTIVES
Staphylococcus spp. are postulated to play a role in peri-implantitis. This study aimed to develop a "submucosal" in vitro biofilm model, by integrating two staphylococci into its composition.
MATERIALS AND METHODS
The standard "subgingival" biofilm contained Actinomyces oris, Fusobacterium nucleatum, Streptococcus oralis, Veillonella dispar, Campylobacter rectus, Prevotella intermedia, Streptococcus anginosus, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, and was further supplemented with Staphyoccous aureus and/or Staphylococcus epidermidis. Biofilms were grown anaerobically on hydroxyapatite or titanium discs and harvested after 64 h for real-time polymerase chain reaction, to determine their composition. Confocal laser scanning microscopy and fluorescence in situ hybridization were used for identifying the two staphylococci within the biofilm.
RESULTS
Both staphylococci established within the biofilms when added separately. However, when added together, only S. aureus grew in high numbers, whereas S. epidermidis was reduced almost to the detection limit. Compared to the standard subgingival biofilm, addition of the two staphylococci had no impact on the qualitative or quantitative composition of the biofilm. When grown individually in the biofilm, S. epidermidis and S. aureus formed small distinctive clusters and it was confirmed that S. epidermidis was not able to grow in presence of S. aureus.
CONCLUSIONS
Staphyoccous aureus and S. epidermidis can be individually integrated into an oral biofilm grown on titanium, hence establishing a "submucosal" biofilm model for peri-implantitis. This model also revealed that S. aureus outcompetes S. epidermidis when grown together in the biofilm, which may explain the more frequent association of the former with peri-implantitis.
Topics: Biofilms; Gingiva; Humans; In Vitro Techniques; Models, Biological; Peri-Implantitis; Staphylococcus aureus; Staphylococcus epidermidis; Titanium
PubMed: 26461083
DOI: 10.1111/clr.12715 -
Scientific Reports Jan 2021Smoking is a risk factor for periodontal disease, and a cause of oral microbiome dysbiosis. While this has been evaluated for traditional cigarette smoking, there is...
Smoking is a risk factor for periodontal disease, and a cause of oral microbiome dysbiosis. While this has been evaluated for traditional cigarette smoking, there is limited research on the effect of other tobacco types on the oral microbiome. This study investigates subgingival microbiome composition in smokers of different tobacco types and their effect on periodontal health. Subgingival plaques were collected from 40 individuals, including smokers of either cigarettes, medwakh, or shisha, and non-smokers seeking dental treatment at the University Dental Hospital in Sharjah, United Arab Emirates. The entire (~ 1500 bp) 16S rRNA bacterial gene was fully amplified and sequenced using Oxford Nanopore technology. Subjects were compared for the relative abundance and diversity of subgingival microbiota, considering smoking and periodontal condition. The relative abundances of several pathogens were significantly higher among smokers, such as Prevotella denticola and Treponema sp. OMZ 838 in medwakh smokers, Streptococcus mutans and Veillonella dispar in cigarette smokers, Streptococcus sanguinis and Tannerella forsythia in shisha smokers. Subgingival microbiome of smokers was altered even in subjects with no or mild periodontitis, probably making them more prone to severe periodontal diseases. Microbiome profiling can be a useful tool for periodontal risk assessment. Further studies are recommended to investigate the impact of tobacco cessation on periodontal disease progression and oral microbiome.
Topics: Adolescent; Adult; Bacteria; Cigarette Smoking; Dental Plaque; Female; Gingiva; Humans; Male; Microbiota; Middle Aged; Periodontitis; Periodontium; Pilot Projects; RNA, Ribosomal, 16S; Tobacco Smoking; United Arab Emirates; Young Adult
PubMed: 33441919
DOI: 10.1038/s41598-020-80937-3 -
Scientific Reports Sep 2018Human intestinal microbes can mediate development of arthritis - Studies indicate that certain bacterial nucleic acids may exist in synovial fluid (SF) and could be...
Human intestinal microbes can mediate development of arthritis - Studies indicate that certain bacterial nucleic acids may exist in synovial fluid (SF) and could be involved in arthritis, although the underlying mechanism remains unclear. To characterize potential SF bacterial nucleic acids, we used 16S rRNA gene amplicon sequencing to assess bacterial nucleic acid communities in 15 synovial tissue (ST) and 110 SF samples from 125 patients with rheumatoid arthritis (RA) and 16 ST and 42 SF samples from 58 patients with osteoarthritis (OA). Our results showed an abundant diversity of bacterial nucleic acids in these clinical samples, including presence of Porphyromonas and Bacteroides in all 183 samples. Agrobacterium, Comamonas, Kocuria, Meiothermus, and Rhodoplanes were more abundant in synovial tissues of rheumatoid arthritis (STRA). Atopobium, Phascolarctobacterium, Rhodotorula mucilaginosa, Bacteroides uniformis, Rothia, Megasphaera, Turicibacter, Leptotrichia, Haemophilus parainfluenzae, Bacteroides fragilis, Porphyromonas, and Streptococcus were more abundant in synovial tissues of osteoarthritis (STOA). Veillonella dispar, Haemophilus parainfluenzae, Prevotella copri and Treponema amylovorum were more abundant in synovial fluid of rheumatoid arthritis (SFRA), while Bacteroides caccae was more abundant in the synovial fluid of osteoarthritis (SFOA). Overall, this study confirms existence of bacterial nucleic acids in SF and ST samples of RA and OA lesions and reveals potential correlations with degree of disease.
Topics: Adult; Algorithms; Arthritis, Rheumatoid; Bacteria; Cytokines; Discriminant Analysis; Humans; Microbiota; Nucleic Acids; Osteoarthritis; Principal Component Analysis; Synovial Fluid; Synovial Membrane
PubMed: 30250232
DOI: 10.1038/s41598-018-32675-w -
Cell Host & Microbe Aug 2020Gut microbiota play a critical role in infant health. It is now accepted that breastmilk contains live bacteria from endogenous and exogenous sources, but it remains...
Gut microbiota play a critical role in infant health. It is now accepted that breastmilk contains live bacteria from endogenous and exogenous sources, but it remains unclear whether these bacteria transfer to the infant gut and whether this process is influenced by breastmilk feeding practices. Here, we show that certain bacteria, including Streptococcus spp. and Veillonella dispar, co-occur in mothers' milk and their infants' stool, and co-occurrence is reduced when infants receive pumped breastmilk. The relative abundances of commonly shared species are positively correlated between breastmilk and stool. Overall, gut microbiota composition is strongly associated with breastfeeding exclusivity and duration but not breastmilk feeding mode (nursing versus pumping). Moreover, breastmilk bacteria contributed to overall gut microbiota variation to a similar extent as other modifiers of the infant microbiome, such as birth mode. These results provide evidence that breastmilk may transfer bacteria to the infant gut and influence microbiota development.
Topics: Breast Feeding; Breast Milk Expression; Cohort Studies; Feces; Feeding Behavior; Female; Gastrointestinal Microbiome; Humans; Infant; Milk, Human; RNA, Ribosomal, 16S; Streptococcus; Veillonella
PubMed: 32652062
DOI: 10.1016/j.chom.2020.06.009