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Microorganisms Jun 2024is a Gram-positive, spore-forming anaerobic bacterial pathogen that causes severe gastrointestinal infection in humans. This review provides background information on... (Review)
Review
is a Gram-positive, spore-forming anaerobic bacterial pathogen that causes severe gastrointestinal infection in humans. This review provides background information on infection and the pathogenesis and toxigenicity of . The risk factors, causes, and the problem of recurrence of disease and current therapeutic treatments are also discussed. Recent therapeutic developments are reviewed including small molecules that inhibit toxin formation, disrupt the cell membrane, inhibit the sporulation process, and activate the host immune system in cells. Other treatments discussed include faecal microbiota treatment, antibody-based immunotherapies, probiotics, vaccines, and violet-blue light disinfection.
PubMed: 38930588
DOI: 10.3390/microorganisms12061206 -
Microorganisms Jun 2024Bacterial diversity and its distribution characteristics in sediments are critical to understanding and revealing biogeochemical cycles in sediments. However, little is...
Bacterial Diversity and Vertical Distribution Patterns in Sandy Sediments: A Study on the Bacterial Community Structure Based on Environmental Factors in Tributaries of the Yangtze River.
Bacterial diversity and its distribution characteristics in sediments are critical to understanding and revealing biogeochemical cycles in sediments. However, little is known about the relationship between biogeochemistry processes and vertical spatial distribution of bacterial communities in sandy sediments. In this study, we used fluorescence quantitative PCR, high-throughput sequencing technology and statistical analysis to explore the vertical distribution pattern of bacterial community diversity and its influencing factors in sandy sediments of the Yangtze River Basin. The aim is to enrich the understanding of the ecological characteristics and functions of bacteria in river ecosystems. The results showed that both sediment bacterial abundance and diversity showed a gradual decrease from surface to bottom in the vertical distribution. The main environmental factors that influenced the bacterial distribution pattern were pore water dissolved oxygen (DO), total nitrogen (TN) concentration and sediment nitrogen (N) content. The dominant bacterial species, and , are suitable for growth and reproduction in high oxygen and nutrient-richer environments, while prefers low oxygen or anaerobic conditions. The vertical distribution pattern of bacteria and its influencing factors in river sandy sediment found in this study differ from the results in mud sediment, which may be related to the larger granular gap between sandy sediment and the lower content of organic matter. The findings of this study further our understanding of the distribution patterns and ecological preferences of microbial communities in river sediments, providing insights into how these communities may adapt to varying environmental conditions.
PubMed: 38930560
DOI: 10.3390/microorganisms12061178 -
Microorganisms Jun 2024Anaerobic exercise decreases systemic pH and increases metabolic acidosis in athletes, altering the acid-base homeostasis. In addition, nutritional recommendations... (Review)
Review
Anaerobic exercise decreases systemic pH and increases metabolic acidosis in athletes, altering the acid-base homeostasis. In addition, nutritional recommendations advising athletes to intake higher amounts of proteins and simple carbohydrates (including from sport functional supplements) could be detrimental to restoring acid-base balance. Here, this specific nutrition could be classified as an acidic diet and defined as 'Westernized athletic nutrition'. The maintenance of a chronic physiological state of low-grade metabolic acidosis produces detrimental effects on systemic health, physical performance, and inflammation. Therefore, nutrition must be capable of compensating for systemic acidosis from anaerobic exercise. The healthy gut microbiota can contribute to improving health and physical performance in athletes and, specifically, decrease the systemic acidic load through the conversion of lactate from systemic circulation to short-chain fatty acids in the proximal colon. On the contrary, microbial dysbiosis results in negative consequences for host health and physical performance because it results in a greater accumulation of systemic lactate, hydrogen ions, carbon dioxide, bacterial endotoxins, bioamines, and immunogenic compounds that are transported through the epithelia into the blood circulation. In conclusion, the systemic metabolic acidosis resulting from anaerobic exercise can be aggravated through an acidic diet, promoting chronic, low-grade metabolic acidosis in athletes. The individuality of athletic training and nutrition must take into consideration the acid-base homeostasis to modulate microbiota and adaptive physiological responses.
PubMed: 38930520
DOI: 10.3390/microorganisms12061138 -
Microorganisms Jun 2024Understanding the microbiological profiles of peri-implant conditions is crucial for developing effective preventive and therapeutic strategies. This narrative review... (Review)
Review
Understanding the microbiological profiles of peri-implant conditions is crucial for developing effective preventive and therapeutic strategies. This narrative review analyzes the microbial profiles associated with healthy peri-implant sites, peri-implant mucositis, and peri-implantitis, along with related microbiological sampling and analyses. Healthy peri-implant sites are predominantly colonized by , , , and species, in addition to Gram-positive cocci and facultatively anaerobic rods, forming a stable community that prevents pathogenic colonization and maintains microbial balance. In contrast, peri-implant mucositis shows increased microbial diversity, including both health-associated and pathogenic bacteria such as red and orange complex bacteria, contributing to early tissue inflammation. Peri-implantitis is characterized by even greater microbial diversity and a complex pathogenic biofilm. Predominant pathogens include , , , , and unique species like and . Additionally, less common species such as and , contributing to disease progression through biofilm formation and increased inflammatory response, along with and human cytomegalovirus with a still not defined role, and contribute to disease progression through biofilm formation, immune modulation, and synergistic inter-kingdom interactions. Future research should standardize diagnostic criteria, employ advanced molecular techniques, integrate microbial data with clinical factors, and highlight inter-kingdom interactions.
PubMed: 38930519
DOI: 10.3390/microorganisms12061137 -
Microorganisms May 2024Two thermophilic spore-forming sulfate-reducing strains, 435 and 781, were isolated from oil and gas reservoirs in Western Siberia (Russia) about 50 years ago. Both...
Two thermophilic spore-forming sulfate-reducing strains, 435 and 781, were isolated from oil and gas reservoirs in Western Siberia (Russia) about 50 years ago. Both strains were found to be neutrophilic, chemoorganotrophic, anaerobic bacteria, growing at 45-70 °C (optimum, 55-60 °C) and with 0-4.5% (/) NaCl (optimum, 0.5-1% NaCl). The major fatty acids were iso-C, iso-C, C, and C. In sulfate-reducing conditions, the strains utilized H/CO, formate, lactate, pyruvate, malate, fumarate, succinate, methanol, ethanol, propanol, butanol, butyrate, valerate, and palmitate. In 2005, based on phenotypic characteristics and a 16S rRNA gene sequence analysis, the strains were described as '' sp. nov. However, this species was not validly published because the type strain was not deposited in two culture collections. In this study, a genomic analysis of strain 435 was carried out to determine its taxonomic affiliation. The genome size of strain 435 was 2.886 Mb with a 55.1% genomic G + C content. The average nucleotide identity and digital DNA-DNA hybridization values were highest between strain 435 and members of the genus , 78.7-93.3% and 25.0-52.2%, respectively; these values were below the species delineation cut-offs (<95-96% and <70%). The cumulative phenotypic and phylogenetic data indicate that two strains represent a novel species within the genus , for which the name sp. nov. is proposed. The type strain is 435 (=VKM B-1492 = DSM 23196). A genome analysis of strain 435 revealed the genes for dissimilatory sulfate reduction, autotrophic carbon fixation via the Wood-Ljungdahl pathway, hydrogen utilization, methanol and organic acids metabolism, and sporulation, which were confirmed by cultivation studies.
PubMed: 38930497
DOI: 10.3390/microorganisms12061115 -
Microorganisms May 2024() is an anaerobic, spore-forming Gram-positive rod responsible for necrotizing gangrene, bacteremia in patients with cancer or gastrointestinal tract infection....
() is an anaerobic, spore-forming Gram-positive rod responsible for necrotizing gangrene, bacteremia in patients with cancer or gastrointestinal tract infection. virulence is due in large part to toxin production. In 2014, a new enterotoxin, BEC (binary enterotoxin of ) encoded by and genes, distinct from enterotoxin (CPE) encoded by the gene, has been described. BEC-producing strains can be causative agents of acute gastroenteritis in humans. We present herein the case of a 64-year-old man who presented to the emergency department of Toulouse University Hospital with pneumonia and septic shock, without digestive symptoms. Blood cultures showed bacteremia and despite appropriate antibiotic treatment the patient passed away 7 h after admission. The characterization of the strain by whole genome sequencing revealed the presence of typical genes of : gene (alpha-toxin, phospholipase C) and (theta-toxin, perfringolysine). Surprisingly, this strain also harbored and genes encoding the recently described BEC toxin. Interestingly, alpha-toxin typing of our isolate and other published BEC isolates showed that they belonged to different PLC subtypes, confirming the high genetic diversity of these strains. To our knowledge, it is the first clinical case reporting bacteremia due to a BEC-producing isolate.
PubMed: 38930477
DOI: 10.3390/microorganisms12061095 -
Microorganisms May 2024Although root (AMR) has been noted as an ingredient in ruminant feed, the impacts of AMR feeding on rumen fermentation and the microbial community structure within the...
Although root (AMR) has been noted as an ingredient in ruminant feed, the impacts of AMR feeding on rumen fermentation and the microbial community structure within the rumen are yet to be evaluated. This study investigated the effects of AMR supplementation on rumen fermentation characteristics and microbial community structures in goats. In two sets of feeding experiments, four Japanese native goats were fed AMR (10 g/kg DM/day/head) for three weeks per experiment. The rumen fluid samples were analyzed using high-performance liquid chromatography for fermentation products and next-generation sequencing for microbial analysis. The rumen fluid samples in the second experiment were also subject to an in vitro anaerobic fermentation test. The results indicated a significant modification, with a higher volatile fatty acid (VFA) content in the rumen fluid of goats in the feeding period than before feeding ( < 0.01). The microbial analysis revealed a significant increase in community diversity ( < 0.05) following AMR feeding, and the rumen bacterial community increased in two families belonging to the order Oscillospirales in Firmicutes ( < 0.05). The phylum Verrucomicrobiota was observed to be significantly less abundant after AMR feeding than during the control period ( < 0.05). Notably, the linear discriminant analysis revealed that the families with largely unknown functions in the rumen (Oscillospiraceae, Rikenellaceae, Muribaculaceae, and vadinBB97) were the determinants of the community split between control and AMR feeding. Increased fermentation rate by AMR feeding was also supported by an in vitro culture experiment, which resulted in faster VFA production without affecting methane production in total gas production. The study demonstrated that AMR can significantly facilitate change in the bacterial community structure in the goat rumen involving a shift of the favoring fibrolytic bacteria towards VFA production. The long-term effects of AMR supplementation and its applicability across different ruminant species, with potential benefits for animal health and productivity, should be addressed.
PubMed: 38930452
DOI: 10.3390/microorganisms12061067 -
Materials (Basel, Switzerland) Jun 2024Anaerobic adhesives (AAs) cure at room temperature in oxygen-deprived spaces between metal substrates. The curing process is significantly influenced by the type of...
Anaerobic adhesives (AAs) cure at room temperature in oxygen-deprived spaces between metal substrates. The curing process is significantly influenced by the type of metal ions present. This study investigates the curing kinetics of a high-strength AA on iron and copper substrates using differential scanning calorimetry (DSC). The activation energy and kinetic parameters were determined with different empiric models, revealing that curing on copper is faster and more complete compared to iron. The findings suggest that copper ions lower the activation energy required for curing, enhancing the adhesive's performance. This research addresses the gap in understanding how metal ions affect AA curing kinetics, offering valuable insights for optimizing adhesive formulations for industrial applications.
PubMed: 38930255
DOI: 10.3390/ma17122886 -
Journal of Personalized Medicine May 2024Ovarian aging is characterized by the accumulation of free radicals, leading to tissue damage and affecting reproductive health. Intravascular laser irradiation of blood...
BACKGROUND
Ovarian aging is characterized by the accumulation of free radicals, leading to tissue damage and affecting reproductive health. Intravascular laser irradiation of blood (ILIB, using a low-energy He-Ne laser) is known for its efficacy in treating vascular-related diseases by reducing free radicals and inflammation. However, its impact on ovarian aging remains unexplored. This study aimed to investigate the effects of ILIB on oxidative stress and energy metabolism in aging ovaries.
METHODS
Genetic analysis was conducted on 75 infertile patients with aging ovaries, divided into ILIB-treated and control (CTRL) groups. Patients underwent two courses of laser treatment, and clinical parameters were evaluated. Cumulus cells were collected for the genetic analysis of oxeiptosis, glycolysis, and the tricarboxylic acid (TCA) cycle.
RESULTS
The analysis of gene expression patterns revealed intriguing findings in ILIB-treated patients compared to the untreated group. Notably, ILIB treatment resulted in significant upregulation of oxeiptosis-related genes AIFM1 and NRF2, suggesting a potential protective effect against oxidative stress-induced cell death. Furthermore, ILIB treatment led to a downregulation of glycolysis-associated gene hexokinase 2 (HK2), indicating a shift away from anaerobic metabolism, along with an increase in PDHA levels, indicative of enhanced mitochondrial function. Consistent with these changes, ILIB-treated patients exhibited elevated expression of the key TCA cycle genes citrate synthase (CS), succinate dehydrogenase complex subunit A (SDHA), and fumarate hydratase (FH), signifying improved energy metabolism.
CONCLUSION
The findings from this study underscore the potential of ILIB as a therapeutic strategy for mitigating ovarian aging. By targeting oxidative stress and enhancing energy metabolism, ILIB holds promise for preserving ovarian function and reproductive health in aging individuals. Further research is warranted to elucidate the underlying mechanisms and optimize the application of ILIB in clinical settings, with the ultimate goal of improving fertility outcomes in women experiencing age-related ovarian decline.
PubMed: 38929772
DOI: 10.3390/jpm14060551 -
Animals : An Open Access Journal From... Jun 2024The elective test for the determination of the effusions etiopathogenesis is represented by physico-chemical analysis and cytology. Nevertheless, the bacterial culture...
The elective test for the determination of the effusions etiopathogenesis is represented by physico-chemical analysis and cytology. Nevertheless, the bacterial culture and antibiotic sensitivity tests are crucial for setting therapy and for the outcome. This study compared cytology with microbiology in the etiologic diagnosis of exudative body cavity effusions in dogs and cats collected from October 2018 to October 2022. All samples underwent aerobic and anaerobic culture and cytology examination. Bacterial identifications were confirmed using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, whereas cytological samples were blindly evaluated either in May Grunwald-Giemsa (MGG) or Gram-stained samples by two board-certified clinical pathologists. A moderate agreement (κ = 0.454) between cytology and bacterial culture was revealed. The sensitivity of the cytological evaluation in our study ranged from 38.5% to 67.9%, and the specificity ranged from 88.9% to 100%, depending on the type of the effusion, so cytology may not be representative of the etiopathogenesis, whereas bacterial culture can misidentify or fail to isolate the correct pathogen for difficult in vitro growing due to the presence of inhibitory substances or contamination. Cytology and bacterial culture results for exudative body cavity effusions in dogs and cats can be misleading if conducted separately, so these two tests should be performed together to increase diagnostic accuracy.
PubMed: 38929381
DOI: 10.3390/ani14121762