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PloS One 2023The nitrate (NO3-) reducing bacteria resident in the oral cavity have been implicated as key mediators of nitric oxide (NO) homeostasis and human health. NO3--reducing... (Meta-Analysis)
Meta-Analysis
The nitrate (NO3-) reducing bacteria resident in the oral cavity have been implicated as key mediators of nitric oxide (NO) homeostasis and human health. NO3--reducing oral bacteria reduce inorganic dietary NO3- to nitrite (NO2-) via the NO3--NO2--NO pathway. Studies of oral NO3--reducing bacteria have typically sampled from either the tongue surface or saliva. The aim of this study was to assess whether other areas in the mouth could contain a physiologically relevant abundance of NO3- reducing bacteria, which may be important for sampling in clinical studies. The bacterial composition of seven oral sample types from 300 individuals were compared using a meta-analysis of the Human Microbiome Project data. This analysis revealed significant differences in the proportions of 20 well-established oral bacteria and highly abundant NO3--reducing bacteria across each oral site. The genera included Actinomyces, Brevibacillus, Campylobacter, Capnocytophaga, Corynebacterium, Eikenella, Fusobacterium, Granulicatella, Haemophilus, Leptotrichia, Microbacterium, Neisseria, Porphyromonas, Prevotella, Propionibacterium, Rothia, Selenomonas, Staphylococcus, Streptococcus and Veillonella. The highest proportion of NO3--reducing bacteria was observed in saliva, where eight of the bacterial genera were found in higher proportion than on the tongue dorsum, whilst the lowest proportions were found in the hard oral surfaces. Saliva also demonstrated higher intra-individual variability and bacterial diversity. This study provides new information on where samples should be taken in the oral cavity to assess the abundance of NO3--reducing bacteria. Taking saliva samples may benefit physiological studies, as saliva contained the highest abundance of NO3- reducing bacteria and is less invasive than other sampling methods. These results inform future studies coupling oral NO3--reducing bacteria research with physiological outcomes affecting human health.
Topics: Humans; Nitrates; Nitrogen Dioxide; Mouth; Bacteria; Saliva; Microbiota; Streptococcus
PubMed: 38127919
DOI: 10.1371/journal.pone.0295058 -
Frontiers in Plant Science 2023In flowering plants, fertilization requires exposing maternal style channels to the external environment to capture pollen and transmit its resident sperm nuclei to...
In flowering plants, fertilization requires exposing maternal style channels to the external environment to capture pollen and transmit its resident sperm nuclei to eggs. This results in progeny seed. However, environmental fungal pathogens invade developing seeds through the style. We hypothesized that prior to environmental exposure, style tissue already possesses bacteria that can protect styles and seed from such pathogens. We further hypothesized that farmers have been inadvertently selecting immature styles over many generations to have such bacteria. We tested these hypotheses in maize, a wind-pollinated crop, which has unusually long styles (silks) that are invaded by the economically-important fungal pathogen (). Here, unpollinated silk-associated bacteria were cultured from a wild teosinte ancestor of maize and diverse maize landraces selected by indigenous farmers across the Americas, grown in a common Canadian field for one season. The bacteria were taxonomically classified using 16S rRNA sequencing. In total, 201 bacteria were cultured, spanning 29 genera, 63 species, and 62 unique OTUs, dominated by and . These bacteria were tested for their ability to suppress which identified 10 strains belonging to 6 species: , and Two anti- strains were sprayed onto silks before/after inoculation, resulting in ≤90% reductions in disease (Gibberella ear rot) and 70-100% reductions in associated mycotoxins (deoxynivalenol and zearalenone) in progeny seeds. These strains also protected progeny seeds post-harvest. Confocal fluorescent imaging showed that one silk bacterium ( AS112) colonized susceptible entry points of on living silks including stigmatic trichomes, wounds, and epidermal surfaces where they formed thick biofilms. Post-infection, AS112 was associated with masses of dead hyphae. These results suggest that the maize style (silk) is endowed with potent bacteria from the mother plant to protect itself and progeny from . The evidence suggests this trait may have been selected by specific indigenous peoples, though this interpretation requires further study.
PubMed: 38111882
DOI: 10.3389/fpls.2023.1292109 -
Frontiers in Cellular and Infection... 2023There is a clinical challenge in diagnosing tuberculous pleurisy accurately and promptly, highlighting the urgent need for a rapid and sensitive diagnostic method. This...
INTRODUCTION
There is a clinical challenge in diagnosing tuberculous pleurisy accurately and promptly, highlighting the urgent need for a rapid and sensitive diagnostic method. This study aimed to evaluate the diagnostic accuracy of metagenomic next-generation sequencing (mNGS) and GeneXpert (MTB) for identifying tuberculous pleurisy and analyzing the microbial profiles of both tuberculous and non-tuberculous pleural effusions.
METHODS
The study enrolled 31 patients with suspected tuberculous pleurisy, of which 15 were confirmed to have tuberculous pleurisy and subsequently allocated to the tuberculous pleurisy group (TP group), while the remaining 16 individuals were assigned to the non-tuberculous pleurisy group (NTP group). mNGS and GeneXpert MTB were performed on pleural effusion samples, and the diagnostic accuracy of both tests was compared. We employed established formulas to compute crucial indicators, including sensitivity, specificity, missed diagnosis rate, misdiagnosed rate, positive predictive value (PPV), and negative predictive value (NPV).
RESULTS
The results showed that both tests had high specificity (100%) and positive predictive value (100%) for detecting tuberculous pleurisy, along with comparable sensitivity (46.67% for mNGS and 40.0% for GeneXpert MTB). Further analysis of the combined efficacy of mNGS and GeneXpert MTB showed that the combined test had a sensitivity of 66.67% and a specificity of 100%. mNGS analysis revealed that MTB was detected in 7 out of 15 patients with tuberculous pleural effusions, while non-tuberculous pleural effusions were associated with a diverse range of microbial genera and species. The most frequently detected genera at the microbial genus level in the NTP group were spp. (6/16), spp. (5/16), and spp. (5/16).
DISCUSSION
These findings suggest that mNGS and GeneXpert MTB are useful diagnostic tools for identifying patients with tuberculous pleurisy, and mNGS can provide valuable insights into the microbial profiles of both tuberculous and non-tuberculous pleural effusions.
Topics: Humans; Mycobacterium tuberculosis; Tuberculosis, Pleural; High-Throughput Nucleotide Sequencing; Sensitivity and Specificity; Pleural Effusion
PubMed: 38089819
DOI: 10.3389/fcimb.2023.1243441 -
Frontiers in Medicine 2023Peritoneal dialysis-related peritonitis (PDRP) caused by . is very rare, with only 9 cases reported to date. In this study, we report the treatment experiences of 7...
INTRODUCTION
Peritoneal dialysis-related peritonitis (PDRP) caused by . is very rare, with only 9 cases reported to date. In this study, we report the treatment experiences of 7 patients at our peritoneal dialysis center.
METHODS
We retrospectively collected clinical characteristics and antibiotic management of all 7 episodes of PDRP caused by . in 7 patients from at our center over 4 years, and reviewed the documented . PDRP in the literature.
RESULTS
Empiric antibiotic therapy was initiated as soon as possible, and consisted of intraperitoneal (IP) gentamicin in combination with vancomycin. After up to 5 days, gentamicin was changed to meropenem if the treatment was not effective. The intended course of antibiotic treatment was 21-day. Totally, 6 episodes were cured (85.7%), which was higher than reported.
CONCLUSION
The 21-day antibiotic therapy program by combining vancomycin and meropenem may benefit the management of . PDRP.
PubMed: 38076234
DOI: 10.3389/fmed.2023.1297296 -
Microbiology Resource Announcements Jan 2024Bacteriophage Alucard is a lytic phage isolated from the soil collected in southern Maine on NRRL B-24224. Alucard has siphovirus morphology with a 17,363-bp genome...
Bacteriophage Alucard is a lytic phage isolated from the soil collected in southern Maine on NRRL B-24224. Alucard has siphovirus morphology with a 17,363-bp genome encoding 25 putative genes. Based on gene content similarity to actinobacteriophages, Alucard is assigned to cluster EE.
PubMed: 38051077
DOI: 10.1128/mra.01017-23 -
Saudi Journal of Biological Sciences Dec 2023sp. strain 1S1, an arsenic-resistant bacterial strain, was isolated with 75 mM MIC against arsenite. Brownish precipitation with silver nitrate appeared, which...
sp. strain 1S1, an arsenic-resistant bacterial strain, was isolated with 75 mM MIC against arsenite. Brownish precipitation with silver nitrate appeared, which confirmed its oxidizing ability against arsenite. The bacterial genomic DNA underwent Illumina and Nanopore sequencing, revealing a distinctive cluster of genes spanning 9.6 kb associated with arsenite oxidation. These genes were identified within an isolated bacterial strain. Notably, the smaller subunit () of the arsenite oxidizing gene at the chromosomal DNA locus (Prokka_01508) was pinpointed. This gene, , is pivotal in arsenite oxidation, a process crucial for energy metabolism. Upon thorough sequencing analysis, only a singular megaplasmid was detected within the isolated bacterial strain. Strikingly, this megaplasmid did not harbor any genes responsible for arsenic resistance or detoxification. This intriguingly indicates that the bacterial strain relies on the arsenic oxidizing genes present for its efficient arsenic oxidation capability. This is especially true for sp. strain 1S1. Subsequently, a segment of genes linked to arsenic resistance was successfully cloned into (DH5a). The fragment of arsenic-resistant genes was cloned in (DH5), further confirmed by the AgNO method. This genetically engineered (DH5) can decontaminate arsenic-contaminated sites.
PubMed: 38046866
DOI: 10.1016/j.sjbs.2023.103846 -
Microbiology Resource Announcements Dec 2023Bacteriophages Phonegingi and Dropshot were isolated from soil in North Carolina using the host . Both phages have siphovirus morphologies. Based on gene content...
Bacteriophages Phonegingi and Dropshot were isolated from soil in North Carolina using the host . Both phages have siphovirus morphologies. Based on gene content similarity to one another and to other actinobacteriophages, both phages are assigned to phage cluster GA.
PubMed: 38014965
DOI: 10.1128/MRA.00918-23 -
Genes Oct 2023(Thunberg) (Coleoptera: Coccinellidae) is a dominant natural enemy of insect pests in farmland ecosystems. It also serves as an important non-target insect for...
(Thunberg) (Coleoptera: Coccinellidae) is a dominant natural enemy of insect pests in farmland ecosystems. It also serves as an important non-target insect for environmental safety evaluations of transgenic crops. Widespread planting of transgenic crops may result in direct or indirect exposure of to recombinant (Bt) protein, which may in turn affect the biological performance of this natural enemy by affecting the microflora. However, the effects of Bt proteins (such as Cry1B) on the microbiota are currently unclear. Here, we used a high-throughput sequencing method to investigate differences in the microbiota resulting from treatment with Cry1B compared to a sucrose control. The results demonstrated that the microbiome was dominated by Firmicutes at the phylum level and by Staphylococcus at the genus level. Within-sample (α) diversity indices demonstrated a high degree of consistency between the microbial communities of treated with the sucrose control and those treated with 0.25 or 0.5 mg/mL Cry1B. Furthermore, there were no significant differences in the abundance of any taxa after treatment with 0.25 mg/mL Cry1B for 24 or 48 h, and treatment with 0.5 mg/mL Cry1B for 24 or 48 h led to changes only in , a member of the phylum Firmicutes. Treatment with a high Cry1B concentration (1.0 mg/mL) for 24 or 48 h caused significant changes in the abundance of specific taxa (e.g., , , , and ). However, compared with the control, most taxa remained unchanged. The statistically significant differences may have been due to the stimulatory effects of treatment with a high concentration of Cry1B. Overall, the results showed that Cry1B protein could alter endophytic bacterial community abundance, but not composition, in . The effects of Bt proteins on endophytes and other parameters in non-target insects require further study. This study provides data support for the safety evaluation of transgenic plants.
Topics: Animals; Bacterial Proteins; Coleoptera; Insecta; Bacillus thuringiensis; Microbiota; Sucrose
PubMed: 38002951
DOI: 10.3390/genes14112008 -
Toxics Nov 2023Fluoride (F) and arsenic (As) are two major contaminants of water and soil systems around the globe, causing potential toxicity to humans, plants, animals, and microbes....
Fluoride (F) and arsenic (As) are two major contaminants of water and soil systems around the globe, causing potential toxicity to humans, plants, animals, and microbes. These contaminated soil systems can be restored by microorganisms that can tolerate toxic stress and provide rapid mineralization of soil, organic matter, and contaminants, using various tolerance mechanisms. Thus, the present study was undertaken with the arsenic hyper-tolerant bacterium strain IR-1 to determine its tolerance and toxicity to increasing doses of fluoride, either individually or in combination with arsenic, in terms of growth inhibition using a toxicity unit model. The minimum inhibitory concentration (MIC)and half maximal inhibitory concentration (IC) values for fluoride increased, from 9 g/L to 11 g/L and from 5.91 ± 0.1 g/L to 6.32 ± 0.028 g/L, respectively, in the combination (F + As) group. The statistical comparison of observed and expected additive toxicities, with respect to toxicity unit (TU difference), using Student's -test, was found to be highly significant ( < 0.001). This suggests the antagonistic effect of arsenic on fluoride toxicity to the strain IR-1. The unique stress tolerance of IR-1 ensures its survival as well as preponderance in fluoride and arsenic co-contaminated sites, thus paving the way for its possible application in the natural or artificial remediation of toxicant-exposed degraded soil systems.
PubMed: 37999597
DOI: 10.3390/toxics11110945 -
Biology Nov 2023Two novel strains of sp. and sp. were identified from the intestine of olive flounder () and characterized in vitro as potential probiotics. Feeds without probiotic...
Two novel strains of sp. and sp. were identified from the intestine of olive flounder () and characterized in vitro as potential probiotics. Feeds without probiotic and with a 50:50 mixture of these two strains (1 × 10 CFU/g feed) were denoted as the control and Pro diets, respectively. Three randomly selected tanks (20 flounders/tank, ~11.4 g each) were used for each diet replication. After 8 weeks of feeding, the growth and feed utilization of the flounder in the Pro group improved ( < 0.05) compared to the control. Among four immune parameters, only myeloperoxidase activity was elevated in the Pro group. Serum biochemistry, intestinal microbial richness (Chao1), and diversity (Shannon index) remained unchanged ( ≥ 0.05), but phylogenetic diversity was enriched in the Pro fish intestine. Significantly lower Firmicutes and higher Proteobacteria were found in the Pro diet; the genus abundance in the control and Pro was as follows: > > and > > , respectively. Microbial linear discriminant scores and a cladogram analysis showed significant modulation. Therefore, the combination of two host-associated probiotics improved the growth and intestinal microbial population of flounder and could be supplemented in the Korean flounder industry.
PubMed: 37998042
DOI: 10.3390/biology12111443