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Environmental Microbiology Reports Jun 2024The global landscape of Candida infections has seen a significant shift. Previously, Candida albicans was the predominant species. However, there has been an emergence... (Comparative Study)
Comparative Study
The global landscape of Candida infections has seen a significant shift. Previously, Candida albicans was the predominant species. However, there has been an emergence of non-albicans Candida species, which are often less susceptible to antifungal treatment. Candida kefyr, in particular, has been increasingly associated with infections. This study aimed to investigate the profiles of enzymatic activity and biofilm formation in both clinical and non-clinical isolates of C. kefyr. A total of 66 C. kefyr isolates were analysed. The activities of proteinase and phospholipase were assessed using bovine serum albumin and egg yolk agar, respectively. Haemolysin, caseinolytic and esterase activities were evaluated using specific methods. Biofilm formation was investigated using crystal violet staining. The findings indicated that biofilm and proteinase activity were detected in 81.8% and 93.9% of all the isolates, respectively. Haemolysin activity was observed with the highest occurrence (95.5%) among normal microbiota isolates. Esterase activity was predominantly identified in dairy samples and was absent in hospital samples. Caseinase production was found with the highest occurrence (18.2%) in normal microbiota and hospital samples. Phospholipase activity was limited, found in only 3% of all the isolates. These findings reveal variations in enzyme activity between clinical and non-clinical C. kefyr isolates. This sheds light on their pathogenic potential and has implications for therapeutic strategies.
Topics: Biofilms; Candida; Humans; Candidiasis; Phospholipases; Esterases; Hemolysin Proteins; Peptide Hydrolases; Environmental Microbiology
PubMed: 38923398
DOI: 10.1111/1758-2229.13282 -
Journal of Applied Oral Science :... 2024To evaluate the protective effect of an experimental solution containing TiF4/NaF on the development of radiation-induced dentin caries lesions.
OBJECTIVE
To evaluate the protective effect of an experimental solution containing TiF4/NaF on the development of radiation-induced dentin caries lesions.
METHODOLOGY
bovine root samples were irradiated (70Gy) and distributed as following (n=12/group): Commercial Saliva (BioXtra), NaF (500 ppm F-), TiF4 (500 ppm F), TiF4/NaF (TiF4: 300 ppm F-, NaF: 190 ppm F-), and Phosphate buffer solution (PBS, negative control). Biofilm was produced using biofilm from irradiated patients and McBain saliva (0.2% of sucrose, at 37oC and 5% CO2) for five days. The treatments were applied 1x/day. Colony-forming units (CFU) were counted and demineralization was quantified by transversal microradiography. The ANOVA/Tukey test was applied for all parameters.
RESULTS
All treatments reduced CFU for total microorganisms. TiF4 reduced Lactobacillus sp. (7.04±0.26 log10 CFU/mL) and mutans streptococci (7.18±0.28) CFU the most, when compared to PBS (7.58±0.21 and 7.75±0.17) and followed by NaF (7.12±0.31 and 7.34±0.22) and TiF4/NaF (7.16±0.35 and 7.29± 0.29). TiF4 and Commercial saliva showed the lowest integrated mineral loss (ΔZ-vol%.mm) (1977±150 and 2062±243, respectively) when compared to PBS (4540±335), followed by NaF (2403±235) and TiF4/NaF (2340±200). Commercial saliva was the only to significantly reduce mineral loss (LD-µm) (111±25) compared to PBS (153±24).Mean mineral loss (R-vol%) decreased by 35.2% for TiF4 (18.2±3.3) when compared to PBS (28.1±2.9) Conclusion: TiF4/NaF has a comparable anti-cariogenic effect to TiF4 and Commercial saliva under the model in this study.
Topics: Sodium Fluoride; Cattle; Animals; Dentin; Dental Caries; Biofilms; Fluorides; Saliva; Streptococcus mutans; Time Factors; Analysis of Variance; Microradiography; Cariostatic Agents; Reproducibility of Results; Lactobacillus; Colony Count, Microbial; Tooth Demineralization; Humans; Materials Testing; Reference Values; Treatment Outcome; Statistics, Nonparametric; Titanium
PubMed: 38922242
DOI: 10.1590/1678-7757-2024-0024 -
Journal of Applied Oral Science :... 2024This study compared three protocols for developing artificial white spot lesions (WSL) using biofilm models. (Comparative Study)
Comparative Study
OBJECTIVE
This study compared three protocols for developing artificial white spot lesions (WSL) using biofilm models.
METHODOLOGY
In total, 45 human enamel specimens were sterilized and allocated into three groups based on the biofilm model: Streptococcus sobrinus and Lactobacillus casei (Ss+Lc), Streptococcus sobrinus (Ss), or Streptococcus mutans (Sm). Specimens were incubated in filter-sterilized human saliva to form the acquired pellicle and then subjected to the biofilm challenge consisting of three days of incubation with bacteria (for demineralization) and one day of remineralization, which was performed once for Ss+Lc (four days total), four times for Ss (16 days total), and three times for Sm (12 days total). After WSL creation, the lesion fluorescence, depth, and chemical composition were assessed using Quantitative Light-induced Fluorescence (QLF), Polarized Light Microscopy (PLM), and Raman Spectroscopy, respectively. Statistical analysis consisted of two-way ANOVA followed by Tukey's post hoc test (α=0.05). WSL created using the Ss+Lc protocol presented statistically significant higher fluorescence loss (ΔF) and integrated fluorescence (ΔQ) in comparison to the other two protocols (p<0.001).
RESULTS
In addition, Ss+Lc resulted in significantly deeper WSL (137.5 µm), followed by Ss (84.1 µm) and Sm (54.9 µm) (p<0.001). While high mineral content was observed in sound enamel surrounding the WSL, lesions created with the Ss+Lc protocol showed the highest demineralization level and changes in the mineral content among the three protocols.
CONCLUSION
The biofilm model using S. sobrinus and L. casei for four days was the most appropriate and simplified protocol for developing artificial active WSL with lower fluorescence, higher demineralization, and greater depth.
Topics: Biofilms; Humans; Streptococcus mutans; Dental Caries; Dental Enamel; Lacticaseibacillus casei; Time Factors; Reproducibility of Results; Streptococcus sobrinus; Spectrum Analysis, Raman; Analysis of Variance; Microscopy, Polarization; Statistics, Nonparametric; Tooth Remineralization; Reference Values; Saliva; Tooth Demineralization; Fluorescence
PubMed: 38922241
DOI: 10.1590/1678-7757-2023-0458 -
Journal of Functional Biomaterials Jun 2024Root caries caused by cariogenic bacteria are a burden on a large number of individuals worldwide, especially the elderly. Applying a protective coating to exposed root...
Root caries caused by cariogenic bacteria are a burden on a large number of individuals worldwide, especially the elderly. Applying a protective coating to exposed root surfaces has the potential to inhibit the development of caries, thus preserving natural teeth. This study aimed to develop a novel antibacterial coating to combat root caries and evaluate its effectiveness using the antibacterial monomer dimethylaminohexadecyl methacrylate (DMAHDM). DMAHDM was synthesized and incorporated into a resin consisting of 55.8% urethane dimethacrylate (UDMA) and 44.2% TEG-DVBE (UV) at a 10% mass fraction of glass filler. Multiple concentrations of DMAHDM were tested for their impact on the resin's mechanical and physical properties. biofilms grown on resin disks were analyzed for antibacterial efficacy. Cytotoxicity was assessed against human gingival fibroblasts (HGFs). The results showed an 8-log reduction in colony-forming units (CFUs) against biofilm (mean ± sd; n = 6) ( < 0.05) when 5% DMAHDM was incorporated into the UV resin. There was a 90% reduction in metabolic activity and lactic acid production. A low level of cytotoxicity against HGF was observed without compromising the physical and mechanical properties of the resin. This coating material demonstrated promising physical properties, potent antibacterial effects, and low toxicity, suggesting its potential to protect exposed roots from caries in various dental procedures and among elderly individuals with gingival recession.
PubMed: 38921541
DOI: 10.3390/jfb15060168 -
Biosensors Jun 2024Microbial biofilms present one of the most widespread forms of life on Earth. The formation of microbial communities on various surfaces presents a major challenge in a... (Review)
Review
Microbial biofilms present one of the most widespread forms of life on Earth. The formation of microbial communities on various surfaces presents a major challenge in a variety of fields, including medicine, the food industry, shipping, etc. At the same time, this process can also be used for the benefit of humans-in bioremediation, wastewater treatment, and various biotechnological processes. The main direction of using electroactive microbial biofilms is their incorporation into the composition of biosensor and biofuel cells This review examines the fundamental knowledge acquired about the structure and formation of biofilms, the properties they have when used in bioelectrochemical devices, and the characteristics of the formation of these structures on different surfaces. Special attention is given to the potential of applying the latest advances in genetic engineering in order to improve the performance of microbial biofilm-based devices and to regulate the processes that take place within them. Finally, we highlight possible ways of dealing with the drawbacks of using biofilms in the creation of highly efficient biosensors and biofuel cells.
Topics: Biofilms; Biosensing Techniques; Bioelectric Energy Sources
PubMed: 38920606
DOI: 10.3390/bios14060302 -
International Journal of Nanomedicine 2024This research was to innovate a nanozyme-based therapeutic strategy that combines aggregation-induced emission (AIE) photosensitizers with copper nanozymes. This...
PURPOSE
This research was to innovate a nanozyme-based therapeutic strategy that combines aggregation-induced emission (AIE) photosensitizers with copper nanozymes. This approach is designed to address the hypoxic conditions often found in bacterial infections and aims to boost the effectiveness of photodynamic therapy (PDT) by ensuring sufficient oxygen supply for reactive oxygen species (ROS) generation.
METHODS
Our approach involved the synthesis of dihydroxyl triphenyl vinyl pyridine (DHTPY)-Cu@zoledronic acid (ZOL) nanozyme particles. We initially synthesized DHTPY and then combined it with copper nanozymes to form the DHTPY-Cu@ZOL composite. The nanozyme's size, morphology, and chemical properties were characterized using various techniques, including dynamic light scattering, transmission electron microscopy, and X-ray photoelectron spectroscopy. We conducted a series of in vitro and in vivo tests to evaluate the photodynamic, antibacterial, and wound-healing properties of the DHTPY-Cu@ZOL nanozymes, including their oxygen-generation capacity, ROS production, and antibacterial efficacy against methicillin-resistant Staphylococcus aureus (MRSA).
RESULTS
The DHTPY-Cu@ZOL exhibited proficient HO scavenging and oxygen generation, crucial for enhancing PDT in oxygen-deprived infection environments. Our in vitro analysis revealed a notable antibacterial effect against MRSA, suggesting the nanozymes' potential to disrupt bacterial cell membranes. Further, in vivo studies using a diabetic rat model with MRSA-infected wounds showed that DHTPY-Cu@ZOL markedly improved wound healing and reduced bacterial presence, underscoring its efficacy as a non-antibiotic approach for chronic infections.
CONCLUSION
Our study suggests that DHTPY-Cu@ZOL is a highly promising approach for combating antibiotic-resistant microbial pathogens and biofilms. The biocompatibility and stability of these nanozyme particles, coupled with their improved PDT efficacy position them as a promising candidate for clinical applications.
Topics: Photochemotherapy; Animals; Methicillin-Resistant Staphylococcus aureus; Copper; Anti-Bacterial Agents; Photosensitizing Agents; Wound Infection; Staphylococcal Infections; Reactive Oxygen Species; Imidazoles; Pyridines; Rats; Wound Healing; Male; Humans; Rats, Sprague-Dawley
PubMed: 38919773
DOI: 10.2147/IJN.S458520 -
AIMS Microbiology 2024Transcriptomic and proteomic analysis were performed on 72 h biofilms of the acneic strain and planktonic cultures in the presence of epinephrine. Epinephrine...
Transcriptomic and proteomic analysis were performed on 72 h biofilms of the acneic strain and planktonic cultures in the presence of epinephrine. Epinephrine predominantly downregulated genes associated with various transporter proteins. No correlation was found between proteomic and transcriptomic profiles. In control samples, the expression of 51 proteins differed between planktonic cultures and biofilms. Addition of 5 nM epinephrine reduced this number, and in the presence of 5 µM epinephrine, the difference in proteomic profiles between planktonic cultures and biofilms disappeared. According to the proteomic profiling, epinephrine itself was more effective in the case of biofilms and potentially affected the tricarboxylic acid cycle (as well as alpha-ketoglutarate decarboxylase Kgd), biotin synthesis, cell division, and transport of different compounds in cells. These findings are consistent with recent research on , suggesting that the effects of epinephrine on actinobacteria may be universal.
PubMed: 38919714
DOI: 10.3934/microbiol.2024019 -
NPJ Biofilms and Microbiomes Jun 2024It is becoming increasingly apparent that commensal skin bacteria have an important role in wound healing and infection progression. However, the precise mechanisms...
It is becoming increasingly apparent that commensal skin bacteria have an important role in wound healing and infection progression. However, the precise mechanisms underpinning many of these probiotic interactions remain to be fully uncovered. In this work, we demonstrate that the common skin commensal Cutibacterium acnes can limit the pathogenicity of the prevalent wound pathogen Pseudomonas aeruginosa in vivo. We show that this impact on pathogenicity is independent of any effect on growth, but occurs through a significant downregulation of the Type Three Secretion System (T3SS), the primary toxin secretion system utilised by P. aeruginosa in eukaryotic infection. We also show a downregulation in glucose acquisition systems, a known regulator of the T3SS, suggesting that glucose availability in a wound can influence infection progression. C. acnes is well known as a glucose fermenting organism, and we demonstrate that topically supplementing a wound with glucose reverses the probiotic effects of C. acnes. This suggests that introducing carbon source competition within the wound microenvironment may be an effective way to prevent or limit wound infection.
Topics: Pseudomonas aeruginosa; Glucose; Animals; Type III Secretion Systems; Propionibacterium acnes; Wound Infection; Mice; Pseudomonas Infections; Skin; Carbon; Wound Healing; Antibiosis; Disease Progression; Humans
PubMed: 38918415
DOI: 10.1038/s41522-024-00518-4 -
NPJ Biofilms and Microbiomes Jun 2024The progression of colorectal cancer is closely associated with diet. Fasting-mimicking diet (FMD) is a promising type of dietary intervention that have beneficial...
The progression of colorectal cancer is closely associated with diet. Fasting-mimicking diet (FMD) is a promising type of dietary intervention that have beneficial effects in the prevention and treatment of various cancers. We investigated the therapeutic effect of 4-day FMD against colorectal cancer in mice through immune cell analysis, microbiota composition analysis and anti-PD-1 treatment. These FMD cycles effectively suppressed colorectal cancer growth, reduced cell proliferation and angiogenesis, increased tumor-infiltration lymphocytes especially CD8T cells. FMD stimulated protective gut microbiota, especially Lactobacillus. Supplementation of Lactobacillus johnsonii induced similar results as FMD intervention, which also suppressed tumor growth and increased CD45 and CD8 T cells. Additionally, FMD synthesizing with anti-PD-1 therapy effectively inhibited CRC progression. These findings suggest that Lactobacillus. johnsonii is necessary for the anticancer process of FMD in CRC. FMD through its effects on both gut microbiota and immune system, effectively suppressed colorectal cancer progression in mouse model.
Topics: Gastrointestinal Microbiome; Animals; Colorectal Neoplasms; Mice; Fasting; Disease Progression; Disease Models, Animal; Cell Proliferation; CD8-Positive T-Lymphocytes; Diet; Cell Line, Tumor; Mice, Inbred C57BL; Lactobacillus; Humans
PubMed: 38918380
DOI: 10.1038/s41522-024-00520-w -
Marine Pollution Bulletin Jun 2024Plastic pollution in the ocean is a global environmental hazard aggravated by poor management of plastic waste and growth of annual plastic consumption. Microbial...
Plastic pollution in the ocean is a global environmental hazard aggravated by poor management of plastic waste and growth of annual plastic consumption. Microbial communities colonizing the plastic's surface, the plastisphere, has gained global interest resulting in numerous efforts to characterize the plastisphere. However, there are insufficient studies deciphering the underlying metabolic processes governing the function of the plastisphere and the plastic they reside upon. Here, we collected plastic and seawater samples from Ashmore Reef in Australia to examine the planktonic microbes and plastic associated biofilm (PAB) to investigate the ecological impact, pathogenic potential, and plastic degradation capabilities of PAB in Ashmore Reef, as well as the role and impact of bacteriophages on PAB. Using high-throughput metagenomic sequencing, we demonstrated distinct microbial communities between seawater and PAB. Similar numbers of pathogenic bacteria were found in both sample types, yet plastic and seawater select for different pathogen populations. Virulence Factor analysis further illustrated stronger pathogenic potential in PAB, highlighting the pathogenicity of environmental PAB. Furthermore, functional analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways revealed xenobiotic degradation and fatty acid degradation to be enriched in PABs. In addition, construction of metagenome-assembled genomes (MAG) and functional analysis further demonstrated the presence of a complete Polyethylene (PE) degradation pathway in multiple Proteobacteria MAGs, especially in Rhodobacteriaceae sp. Additionally, we identified viral population presence in PAB, revealing the key role of bacteriophages in shaping these communities within the PAB. Our result provides a comprehensive overview of the various ecological processes shaping microbial community on marine plastic debris.
PubMed: 38917500
DOI: 10.1016/j.marpolbul.2024.116651