Study on the mechanism of action of methane production by co-fermentation of sludge and lignite.

To improve the methanogenic efficiency of lignite anaerobic fermentation and explore innovative approaches to sludge utilization, a co-fermentation technique involving lignite and sludge was employed for converting biomass into biomethane. Volatile suspended solids were introduced as a native enrichment of the sludge and mixed with lignite for fermentation. The synergistic fermentation mechanism between sludge and lignite for biomethane production was analyzed through biochemical methane potential experiments, measurement of various parameters pre- and post-fermentation, observation of bacterial population changes during the peak of reaction, carbon migration assessment, and evaluation of rheological characteristics. The results showed that the addition of sludge in the anaerobic fermentation process improved the microorganisms' ability to degrade lignite and bolstered biomethane production. Notably, the maximum methane production recorded was 215.52 mL/g-volatile suspended solids, achieved at a sludge to coal ratio of 3:1, with a synergistic growth rate of 25.37%. Furthermore, the removal rates of total suspended solids, and total chemical oxygen demand exhibited an upward trend with an increasing percentage of sludge in the mixture. The relative abundance and activity of the methanogens population were found to increase with an appropriate ratio of sludge to lignite. This observation confirmed the migration of carbon between the solid-liquid-gas phases, promoting enhanced system affinity. Additionally, the changes in solid-liquid phase parameters before and after the reaction indicated that the addition of sludge improved the system's degradation capacity. The results of the study hold significant implications in realizing the resource utilization of sludge and lignite while contributing to environmental protection endeavors.

Microbiota of Saliva: A Non-invasive Diagnostic Tool.

Potential of salivary microbiota as a non-invasive diagnostic tool for various diseases are explained in the present review. Traditional diagnostic methods rely on blood, which has limitations in terms of collection and biomarker specificity. We discuss the concept of normal flora and how disruptions in oral microbiota can be indicative of diseases. Saliva, harboring a diverse microbial community, offers promise as a diagnostic biomarker source for oral and non-oral conditions. We delve into the role of microbial dysbiosis in disease pathogenesis and the prospects of using biological indicators like dysbiosis for diagnosis, prediction, and monitoring. This review also emphasizes the significance of saliva microbiota in advancing early disease detection and timely intervention. We addressed the following research question and objectives: Can the microbiota of saliva serve as a non-invasive diagnostic tool for the early detection and monitoring of both oral and non-oral diseases? To achieve this, we will explore the normal flora of microorganisms in the oral cavity, the impact of microbial dysbiosis, and the potential of using specific pathogenic microorganisms as biomarkers. Additionally, we will investigate the correlation between oral and non-oral diseases by analyzing total saliva or site-specific dental biofilms for signs of symbiosis or dysbiosis. This research seeks to contribute valuable insights into the development of a non-invasive diagnostic approach with broad applications in healthcare.

Analysis of sputum microbial flora in chronic obstructive pulmonary disease patients with different phenotypes during acute exacerbations.

BACKGROUND: Increasing studies have shown that the imbalance of the respiratory microbial flora is related to the occurrence of COPD, the severity and frequency of exacerbations and mortality.However, it remains unclear how the sputum microbial flora differs during exacerbations in COPD patients manifesting emphysema phenotype, chronic bronchitis with emphysema phenotype and asthma-COPD overlap phenotype. METHODS: Sputum samples were obtained from 29 COPD patients experiencing acute exacerbations who had not received antibiotics or systemic corticosteroids within the past four weeks.Patients were divided into three groups;emphysema phenotype(E);chronic bronchitis with emphysema phenotype(B+E) and asthma-COPD overlap phenotype(ACO).We utilized metagenomic Next Generation Sequencing (mNGS) technology to analyze the sputum microbial flora in COPD patients with different phenotypes during exacerbations. RESULTS: There was no significant difference in alpha diversity and beta diversity among three groups.The microbial flora composition was similar in all three groups during exacerbations except for a significant increase in Streptococcus mitis in ACO.Through network analysis,we found Candidatus Saccharibacteria oral taxon TM7x and Fusobacterium necrophorum were the core nodes of the co-occurrence network in ACO and E respectively.They were positively correlated with some species and play a synergistic role.In B+E,Haemophilus pittmaniae and Klebsiella pneumoniae had a synergistic effect.Besides,some species among the three groups play a synergistic or antagonistic role.Through Spearman analysis,we found the relative abundance of Streptococcus mitis was negatively correlated with the number of hospitalizations in the past year(r = -0.410,P = 0.027).We also observed that the relative abundance of Prevotella and Prevotella melaninogenica was negatively correlated with age(r = -0.534,P = 0.003;r = -0.567,P = 0.001),while the relative abundance of Streptococcus oralis and Actinomyces odontolyticus was positively correlated with age(r = 0.570,P = 0.001;r = 0.480,P = 0.008).In addition,the relative abundance of Prevotella melaninogenica was negatively correlated with peripheral blood neutrophil ratio and neutrophil to lymphocyte ratio(r = -0.479,P = 0.009;r = -0.555,P = 0.002),while the relative abundance of Streptococcus sanguinis was positively correlated with peripheral blood neutrophil ratio and neutrophil to lymphocyte ratio (r = 0.450,P = 0.014;r = 0.501,P = 0.006).There was also a significant positive correlation between Oribacterium and blood eosinophil counts(r = 0.491,P = 0.007). CONCLUSION: Overall,we analyzed the sputum microbiota of COPD patients with different phenotypes and its relationship with clinical indicators, and explored the relationships between microbiota and inflammation in COPD.We hope to alter the prognosis of patients by inhibiting specific bacterial taxa related to inflammation and using guide individualized treatment in the future research.

Application of combined photobiomodulation and curcumin-loaded iron oxide nanoparticles considerably enhanced repair in an infected, delayed-repair wound model in diabetic rats compared to either treatment alone.

Herein, we attempted to evaluate the therapeutic potential of photobiomodulation (PBM) and curcumin-loaded iron nanoparticles (CUR), alone and in combination, on wound closure rate (WCR), microbial flora by measuring colony-forming units (CFUs), the stereological and biomechanical properties of repairing wounds in the maturation stage of the wound healing course in an ischemic infected delayed healing wound model (IIDHWM) of type I diabetic (TIDM) rats. There were four groups: group 1 was the control, group 2 received CUR, rats in group 3 were exposed to PBM (80 Hz, 890 nm, and 0.2 J/cm2), and rats in group 4 received both PBM and CUR (PBM + CUR). We found CFU was decreased in groups 2, 3, and 4 compared to group 1 (p = 0.000 for all). Groups 2, 3, and 4 showed a considerable escalation in WCR compared to group 1 (p = 0.000 for all). In terms of wound strength parameters, substantial increases in bending stiffness and high-stress load were observed in groups 2, 3, and 4 compared to group 1 (p = 0.000 for all). Stereological examinations revealed decreases in neutrophil and macrophage counts and increases in fibroblast counts in groups 2, 3, and 4compared  to group 1 (p = 0.000 for all). Blood vessel counts were more dominant in the PBM and PBM + CUR groups over group 1 (p = 0.000 for all). CFU and wound strength as well as macrophage, neutrophil, and fibroblast counts were found to be improved in the PBM + CUR and PBM groups compared to the CUR group (ranging from p = 0.000 to p < 0.05). Better results were achieved in the PBM + CUR  treatment  over the PBM therapy. We determined therapy with PBM + CUR, PBM alone, and CUR alone substantially accelerated diabetic wound healing in an IIDHWM of TIDM rats compared to control  group. Concomitantly, the PBM + CUR and PBM groups attained significantly enhanced results for WCR, stereological parameters, and wound strength than the CUR group, with the PBM + CUR results being superior to those of the PBM group.

Airway microecology in rifampicin-resistant and rifampicin-sensitive pulmonary tuberculosis patients.

BACKGROUND: Pulmonary tuberculosis is a chronic infectious disease of the respiratory system. It is still one of the leading causes of death from a single infectious disease, but it has been stuck in the study of a single pathogen. Recent studies have shown that many diseases are associated with disruption of the native microbiota. In this study we investigated the occurrence of tuberculosis and the correlation between drug resistance and respiratory flora. High-throughput 16 S rRNA gene sequencing was used to characterize the respiratory microbiota composition of 30 tuberculosis (TB) affected patients and compared with 30 healthy (H) controls. According to their Gene Xpert results, 30 pulmonary tuberculosis patients were divided into 12 persons in the drug-sensitive group (DS0) and 18 persons in the drug-resistant group (DR0). The microbial flora of the two were compared with the H group. RESULTS: The data generated by sequencing showed that Firmicutes, Proteus, Bacteroides, Actinomyces and Fusobacterium were the five main bacterial phyla detected, and they constituted more than 96% of the microbial community. The relative abundances of Fusobacterium, Haemophilus, Porphyromonas, Neisseria, TM7, Spirochetes, SR1, and Tenericutes in the TB group was lower than that of the H group, and Granulicatella was higher than the H group. The PcoA diagrams of the two groups had obvious clustering differences. The Alpha diversity of the TB group was lower than that of the H group, and the Beta diversity was higher than that of the H group (P < 0.05). The relative abundance of Streptococcus in the DS0 group was significantly higher than that in the DR0 group (P < 0.05). CONCLUSION: Pulmonary tuberculosis can cause disorders of the respiratory tract microbial flora, in which the relative abundance of Streptococcus was significantly different between rifampicin-sensitive and rifampicin-resistant patients.

The evolution of dam-litter microbial flora from birth to 60 days of age.

BACKGROUND: Early bacterial colonization in puppies is still a poorly understood phenomenon. Although the topic is of considerable interest, a big gap in knowledge still exists on the understanding of timing and features of neonatal gut colonization. Thence, the purpose of this study was to evaluate the relationship between dam and litter microbial flora, in vaginally delivered puppies, from birth to two months of age. Bacteria were identified using MALDI-TOF, an accurate and sensitive method, and cluster analysis of data provided a new insight on the investigated topic. METHODS: Six dam-litter units of two medium size breeds were enrolled in the study. Vaginal and colostrum/milk samples were collected from dams after delivery and 48h post-partum, while rectal samples were taken from dams and puppies after delivery and at day 2, 30 and 60 (T2, T30 and T60, respectively) post-partum. Bacterial isolation and identification were performed following standard techniques, then the data were analyzed using a new approach based on bacterial genus population composition obtained using a wide MALDI-TOF screening and cluster analysis. RESULTS: Forty-eight bacteriological samples were collected from the dams and 145 from their 42 puppies. Colostrum/milk samples (n = 12) showed a bacterial growth mainly limited to few colonies. Staphylococci, Enterococci, E. coli, Proteus spp. were most frequently isolated. All vaginal swabs (n = 12) resulted in bacteria isolation (medium to high growth). Streptococci, Enterococci, E. coli were the most frequently detected. E. coli, Proteus mirabilis, Enterococcus spp., Streptococcus spp. were often obtained from dams' and puppies' rectal swabs. Clostridia, not isolated in any other sampling site, were rarely found (n = 3) in meconium while they were more frequently isolated at later times (T2: n = 30; T30: n = 17; T60: n = 27). Analysis of the bacterial genus pattern over time showed a statistically significant reduction (P < 0.01) in the heterogeneity of microbial composition in all time points if compared to birth for each dam-litter unit. These results were confirmed with cluster analysis and two-dimensional scaling. CONCLUSION: This novel data analysis suggests a fundamental role of the individual dam in seeding and shaping the microbiome of the litter. Thus, modulating the dam's microbiota may positively impact the puppy microbiota and benefit their health.

Effectiveness of anti-epidemic measures on ensuring indoor air quality of cleanrooms in a tertiary care hospital.

OBJECTIVES: Maintaining cleanrooms in a hospital is a key part of preventing healthcare-associated infections (HAIs). The aim of this work was to verify the effectiveness of anti-epidemic measures to ensure air quality in cleanrooms in a tertiary care hospital. METHODS: The study was based on the application of anti-epidemic measures and verification of their effectiveness by regular indoor air monitoring between the years 2014-2019. Monitoring was performed according to a recommended procedure based on European standards for cleanrooms. RESULTS: The results demonstrate a reduction in the number of airborne particles and the number of colonies, as well as the elimination of fungi and conditioned pathogens in air samples. CONCLUSIONS: The authors emphasize the importance of established anti-epidemic measures and regular monitoring for the prevention of HAIs.

Effect of essential oil supplementation to diet on meat quality, fatty acid composition, performance parameters and intestinal microbiota of Japanese quails.

The effect of essential oil (EO) supplementation on carcass characteristics of Japanese quails and interactions between ingredients and intestinal morphology were investigated in this study. A total of 250 quails were fed different diet: D1, basal diet (BD); D2, BD plus palmarosa oil (PO; 100 µg/kg diet); D3, BD plus lemon myrtle oil (LMO; 100 µg/kg diet); D4, BD plus α-Tops (mixture of α-terpineol, cineole and terpinene-4-ol; 100 µg/kg diet); and D5, BD plus cyclodextrin. Overall growth performance was determined at multiple time points during 35 days of experiment. Carcass characteristics (fatty acid, pH and colour), intestinal morphology and the expression levels of meat quality-related genes including the insulin-like growth factor (IGF-1), myogenin and avian uncoupling protein (avUCP) were examined at the end of the trial. Additionally, intestinal microbiome of quails was studied by next-generation sequencing-based culture-independent analysis. Although the inclusion of EOs into the diet had no effect on the growth performance of quails and the microbial profile, the significant changes in pH24 and colour (a*) of the quail's breast muscle (p < .05) in the group receiving PO were observed. Additionally, oleic acid content in the breast muscle was significantly higher in the EOs supplemented groups (p < .01). Quails fed the PO supplemented diet had higher villus and relatively rich in oleic acid. The expression levels of IGF-1 and myogenin genes in quail's muscle were not affected, but the expression of avUCP gene was significantly lower in quails fed with LMO and α-Tops (p < .05). The results demonstrated variable effects of these treatments on intestinal morphology. Taken together, dietary inclusion of EOs is found to be beneficial and hence can be recommended for improving the quality of poultry meat.

The 1975 type Japanese diet improves the gut microbial flora and inhibits visceral fat accumulation in mice.

In this study, the 1975 type Japanese diet was prepared and its effects and related mechanism were examined in mice. Mice were assigned to three experimental groups, the CD group fed a control diet, the MD group fed a modern Japanese diet (MD), and the JD group fed the 1975 type Japanese diet (JD) for 4 weeks. MD and JD were low protein, high fat, and high carbohydrate diets compared to the CD. Total white adipose tissue weights were significantly increased in the MD group compared to those in the CD group and were decreased in the JD group compared to those in the MD group. In the JD group, adipocyte hypertrophy was inhibited and Hsl mRNA expression was enhanced in epididymal adipose tissue and the number of bacteria associated with the production of short chain fatty acids was increased. Therefore, the JD inhibits lipid accumulation in white adipose tissue. ABBREVIATIONS: Actb: ß-actin; ALT: alanine aminotransferase; ANOVA: analyses of variance; AST: aspartate aminotransferase; Fas: fatty acid synthase; G6pdx: glucose 6-phosphate dehydrogenase; HE: hematoxylin and eosin; HOMA-IR: Homeostatic model assessment for insulin resistance; Hsl: hormone-sensitive lipase; JD: 1975 type Japanese diet; Leptin: leptin; MD: modern Japanese diet; Me: malic enzyme; NEFA: non-esterified fatty acids; PL: phospholipids; Pparδ: peroxisome proliferator-activated receptor delta; Pparγ: peroxisome proliferator-activated receptor gamma; qRT-PCR: quantitative reverse transcriptase polymerase chain reaction; SAMP8: senescence-accelerated prone 8; SEM: standard error of the mean; Srebp1c: Sterol regulatory element binding protein 1c; TBARS: thiobarbituric acid reactive substance; TC: total cholesterol; TG: Triacylglycerol; V3: variable regions 3.

Effects of different preservation methods on biomacromolecules and microbial flora. / 不同保存方式对生物大分子物质及微生物菌群的影响.

OBJECTIVES: To compare the effects of different preservation methods on biomacromolecules and microbial flora at different time points, and to understand the relationship between different cryopreservation methods, storage time and sample stability. METHODS: Tissue samples were taken from patients who underwent radical gastrectomy in the Third Xiangya Hospital, Central South University. Stool samples were obtained from volunteers. The tissue samples were stored in a refrigerator at -80 ℃ (-80 ℃ refrigerator group) and a liquid nitrogen tank (liquid nitrogen tank group), respectively. According to the preservation method, the stool samples were divided into a -80 ℃ refrigerator group, a liquid nitrogen tank group, a -80 ℃ refrigerator+ethanol absolute group, a liquid nitrogen tank+ethanol absolute group, and a room temperature+ethanol absolute group. Relevant indexes were examined and analyzed at the 0 month (fresh sample), 3th month, 6th month, 9th month and 12th month respectively to evaluate the sample stability with different preservation methods. RESULTS: Compared with the fresh sample, there was no significant changes in the protein concentration and the absorbance value of RNA in the samples in the liquid nitrogen tank group after 12 months of storage (both P>0.05); but the protein concentration of the tissue samples was decreased in the samples of the -80 ℃ refrigerator group after 12 months of storage (P<0.05), while the absorbance value of RNA was increased in the 9th and 12th months (both P>0.05). For the microbial flora of feces samples, at the phylum level, the flora changed significantly with time in the room temperature+ethanol absolute group, and the abundance of bacteroidetes, clostridium and proteobacteria was decreased significantly, while the abundance of firmicutes was increased significantly. At the family level, the abundance of bacteroidaceae, trichospirillaceae and veroniaceae was lower than that in the fresh sample, and the abundance of rumenbacteriaceae was higher than that in the fresh sample. In the 4 cryopreserved groups (-80 ℃ refrigerator group, liquid nitrogen tank group, -80 ℃ refrigerator+ethanol absolute group, liquid nitrogen tank+ethanol absolute group), the abundance of enterobacteriaceae was higher than that in the fresh sample. The analysis of Alpha and Beta diversity indicated that the species diversity, richness and flora structure of samples in the room temperature group were different from those in the fresh sample and other experimental groups. CONCLUSIONS: The protein concentration and RNA purity in the tissue samples preserved by liquid nitrogen tank are relatively stable; the protein concentration and RNA purity of the tissue samples which preserved in the -80 ℃ refrigerator are also relatively stable within half a year; the -80 ℃ refrigerator and liquid nitrogen tank cryopreservation can both maintain the microbial flora stability of the fecal specimen; the room temperature+ethanol absolute is not suitable for long-term preservation of stool samples.

Oral Microbiological Evidence among Palliative Patients: An Integrated Systematic Review.

Life-limiting diseases such as cancers and its related treatments often compromise normal oral microbial flora and predispose a palliative patient to diverse oral infections. Knowledge on microbial flora in the oral cavity of patients with life-limiting diseases is essential to develop treatment options for clinical practitioners. This review aimed to systematically synthesize the published evidence on the oral microbiology of palliative patients. An integrative review was undertaken with defined search strategy from five databases with manual search through key journals and reference list. Studies included were published during the year 2000-2017 focusing on microbiological evidence associated with oral conditions among palliative patients. Candida presence was reported in the oral cavity of terminally ill patients in seven of nine articles, with Candida albicans being the predominant species. The majority of the included studies used oral swabs as a technique for isolation of the organism. This review is first to systematically synthesize the published evidence on the oral microbial flora of palliative patients, taking into account the techniques for identification of the microbiota. Larger multicenter studies may help in developing standardized clinical guidelines for the oral care of these patients.

Friend turned foe: evolution of enterococcal virulence and antibiotic resistance.

The enterococci are an ancient genus that evolved along with the tree of life. These intrinsically rugged bacteria are highly adapted members of the intestinal consortia of a range of hosts that spans the animal kingdom. Enterococci are also leading opportunistic hospital pathogens, causing infections that are often resistant to treatment with most antibiotics. Despite the importance of enterococci as hospital pathogens, the vast majority live outside of humans, and nearly all of their evolutionary history took place before the appearance of modern humans. Because hospital infections represent evolutionary end points, traits that exacerbate human infection are unlikely to have evolved for that purpose. However, clusters of traits have converged in specific lineages that are well adapted to colonize the antibiotic-perturbed gastrointestinal tracts of patients and that thrive in the hospital environment. Here we discuss these traits in an evolutionary context, as well as how comparative genomics is providing new insights into the evolution of the enterococci.

Mycoplasma hafezii sp. nov., isolated from the trachea of a peregrine falcon (Falco peregrinus).

Mycoplasma species are well known pathogens in avian medicine, especially in poultry. However, several Mycoplasma species have been regularly found in the respiratory tract of birds of prey which seem to be commensals in these bird species. In previous studies, an unknown Mycoplasma species which caused false positive results in a Mycoplasma meleagridis-specific PCR, was isolated from a tracheal swab of a clinically healthy, captive, adult peregrine falcon (Falco peregrinus). The isolate appeared in typical fried-egg-shaped colonies on SP4 agar plates and was dependent on sterol for growth. Acid was produced from glucose, but no arginine or urea was hydrolysed. The temperature range for growth was 28-44 °C, with an optimum at 37 °C. Strain M26T was serologically distinct from all species of the genus Mycoplasma with 16S rRNA gene sequence similarity ≥94 %. Biochemical, serological and molecular biological properties demonstrate that this organism represents a novel species of the genus Mycoplasma, for which the name Mycoplasma hafezii sp. nov. is proposed; the type strain is M26T (NCTC 13928, DSM 27652).

An improvement in acute wound healing in mice by the combined application of photobiomodulation and curcumin-loaded iron particles.

Here, we examined the combined effect of pulse wave photobiomodulation (PBM) with curcumin-loaded superparamagnetic iron oxide (Fe3O4) nanoparticles (curcumin), in an experimental mouse model of acute skin wound. Thirty male adult mice were randomly allocated into 5 groups. Group 1 was served as the control group. Group 2 was a placebo and received distilled water, as a carrier of curcumin. Group 3 received laser (890 nm, 80 Hz, 0.2 J/cm2). Group 4 received curcumin by taking four injections around the wound. Group 5 received laser + curcumin. One full-thickness excisional round wound was made on the back of all the mice. On days 0, 4, 7, and 14, bacterial flora, wound surface area, and tensile strength were examined and microbiological examinations were performed. In case of wound closure, the two-way ANOVA shows that wound surface area of entire groups decreased progressively. However, the decrease in laser + curcumin and laser groups, and especially data from laser + curcumin group were statistically more significant, in comparison with the other groups (F statistics = 2.28, sig = 0.019). In terms of microbiology, the two-way ANOVA showed that laser, and laser + curcumin groups have statistically a lower bacterial count than the curcumin, control, and carrier groups (F statistics = 35, sig = 0 = 000). Finally, the one-way ANOVA showed that laser + curcumin, curcumin, and curcumin significantly increased wound strength, compared to the control and carrier groups. Furthermore, laser + curcumin significantly increased wound strength, compared to the control, laser, and curcumin groups (LSD test, p = 0.003, p = 0.002, and p = 0.005, respectively). In conclusion, curcumin nanoparticles, pulse wave laser, and pulse wave laser + curcumin nanoparticles accelerate wound healing, through a significant increase in wound closure rate, as well as wound strength, and a significant decrease in Staphylococcus aureus counts. Furthermore, the statistical analysis of our data suggests that the combined treatment of pulse wave laser + curcumin nanoparticles enhances the wound closure rate, and wound strength, compared to the laser and curcumin nanoparticles alone.

The effect of combined pulsed wave low-level laser therapy and mesenchymal stem cell-conditioned medium on the healing of an infected wound with methicillin-resistant Staphylococcal aureus in diabetic rats.

This study aims to investigate the combined effects of Pulsed wave low-level laser therapy (PW LLLT) and human bone marrow mesenchymal stem cell-conditioned medium (hBM-MSC-CM) on the microbial flora and tensiometrical properties of an infected wound model with methicillin-resistant staphylococcal aureus (MRSA) in an experimental model for Type 1 diabetes mellitus (TIDM). TIDM was induced in rats by streptozotocin (STZ). One full-thickness excision was made on the backs of the rats. Next, the rats were divided into the following groups: Group 1 was the control (placebo) group; Group 2 received hBM-MSCs-CM four times; Group 3 were laser PWLLLT (890 nm, 80 Hz, 0.2 J/cm2 ); and Group 4 received hBM-MSCs-CM +LASER. Wounds were infected with MRSA. Microbiological examinations were performed on days 4, 7, and 15. Tensiometerical examinations were carried out on the 15th day. One-way analysis of variance showed that laser and CM alone and/or in combination significantly increases the tensiomerical properties of the repaired wounds compared with control wounds. A combination of PW laser and CM was statistically more effective than other treated groups. Two-way analysis of variance showed that laser and CM alone and/or in combination significantly decreases the colony-forming units (CFUs) compared with the control group. The application of hBM-MSC-CM and PWlaser alone and/or together significantly accelerates the wound-healing process in MRSA-infected cutaneous wounds in TI DM in rats. Additionally, a combined application of hBM-MSC-CM and PWlaser demonstrates a synergistic effect on the wound-healing process in MRSA-infected cutaneous wounds in Type I DM rats.

What causes the spatial heterogeneity of bacterial flora in the intestine of zebrafish larvae?

Microbial flora in the intestine has been thoroughly investigated, as it plays an important role in the health of the host. Jemielita et al. (2014) showed experimentally that Aeromonas bacteria in the intestine of zebrafish larvae have a heterogeneous spatial distribution. Although bacterial aggregation is important biologically and clinically, there is no mathematical model describing the phenomenon and its mechanism remains largely unknown. In this study, we developed a computational model to describe the heterogeneous distribution of bacteria in the intestine of zebrafish larvae. The results showed that biological taxis could cause the bacterial aggregation. Intestinal peristalsis had the effect of reducing bacterial aggregation through mixing function. Using a scaling argument, we showed that the taxis velocity of bacteria must be larger than the sum of the diffusive velocity and background bulk flow velocity to induce bacterial aggregation. Our model and findings will be useful to further the scientific understanding of intestinal microbial flora.

Biosynthesis of Metal Nanoparticles via Microbial Enzymes: A Mechanistic Approach.

During the last decade, metal nanoparticles (MtNPs) have gained immense popularity due to their characteristic physicochemical properties, as well as containing antimicrobial, anti-cancer, catalyzing, optical, electronic and magnetic properties. Primarily, these MtNPs have been synthesized through different physical and chemical methods. However, these conventional methods have various drawbacks, such as high energy consumption, high cost and the involvement of toxic chemical substances. Microbial flora has provided an alternative platform for the biological synthesis of MtNPs in an eco-friendly and cost effective way. In this article we have focused on various microorganisms used for the synthesis of different MtNPs. We also have elaborated on the intracellular and extracellular mechanisms of MtNP synthesis in microorganisms, and have highlighted their advantages along with their challenges. Moreover, due to several advantages over chemically synthesized nanoparticles, the microbial MtNPs, with their exclusive and dynamic characteristics, can be used in different sectors like the agriculture, medicine, cosmetics and biotechnology industries in the near future.

Sulfate, nitrate and blood pressure - An EPIC interaction between sulfur and nitrogen.

Nitrate (NO3-)-rich foods such as green leafy vegetables are not only part of a healthy diet, but increasingly marketed for primary prevention of cardiovascular disease (CVD) and used as ergogenic aids by competitive athletes. While there is abundant evidence for mild hypotensive effects of nitrate on acute application there is limited data on chronic intake in humans, and results from animal studies suggest no long-term benefit. This is important as nitrate can also promote the formation of nitrosamines. It is therefore classified as 'probably carcinogenic to humans', although a beneficial effect on CVD risk might compensate for an increased cancer risk. Dietary nitrate requires reduction to nitrite (NO2-) by oral commensal bacteria to contribute to the formation of nitric oxide (NO). The extensive crosstalk between NO and hydrogen sulfide (H2S) related metabolites may further affect nitrate's bioactivity. Using nitrate and nitrite concentrations of drinking water - the only dietary source continuously monitored for which detailed data exist - in conjunction with data of >14,000 participants of the EPIC-Norfolk study, we found no inverse associations with blood pressure or CVD risk. Instead, we found a strong interaction with sulfate (SO42-). At low sulfate concentrations, nitrate was inversely associated with BP (-4mmHg in top quintile) whereas this was reversed at higher concentrations (+3mmHg in top quintile). Our findings have a potentially significant impact for pharmacology, physiology and public health, redirecting our attention from the oral microbiome and mouthwash use to interaction with sulfur-containing dietary constituents. These results also indicate that nitrate bioactivation is more complex than hitherto assumed. The modulation of nitrate bioactivity by sulfate may render dietary lifestyle interventions aimed at increasing nitrate intake ineffective and even reverse potential antihypertensive effects, warranting further investigation.

Microbial flora and resistance in ophthalmology: a review.

Antibiotic resistance in systemic infection is well-researched and well-publicized. Much less information is available on the resistance of normal ocular microbiome and that of ophthalmic infections. An understanding of the distribution of ocular microorganisms may help us in tailoring our empiric treatment, as well as in choosing effective pre-, peri- and postoperative management, to achieve the best results for patients. This study aims to summarize and review the available literature on the subject of normal ocular flora and its resistance, as well as the broader topic of antibiotic resistance in ophthalmology.

Effect of 12-month weekly professional oral hygiene care on the composition of the oral flora in dentate, dependent elderly residents: A prospective study.

OBJECTIVE: To study the effect of weekly professional oral hygiene care on the proportion of micro-organisms associated with good oral health, caries, and periodontal and soft tissue diseases in oral biofilms in dentate, dependent elderly residents. BACKGROUND: Assisted oral hygiene care reduces the plaque score and number of micro-organisms in the oral biofilms in elderly residents. Less is known about the effect on the quality/composition of the remaining oral flora. MATERIALS AND METHODS: Participants comprised 33 residents in the study and 35 in the control group. Dental status (≥10 natural teeth and no removable dentures to be included), plaque score, salivary secretion rate and prescription medicines were recorded. Duplicate samples, collected from supragingival plaque and tongue, were analysed using cultivation technique. Differences between and within groups were analysed using one-way and two-way ANOVA, respectively. RESULTS: At the baseline, the number of teeth in the participants (mean age, 83.7 ± 7.4 years) was 22.0 ± 4.5. The number of prescription medicines was 9.4 ± 4.5. Seventy-six per cent had low salivary secretion rate. Fifty per cent had "visible thick" supragingival plaque. At the 12-month registration, "no visible" or "visible but thin" plaque was recorded in 92% in the study group. The proportions of bacteria associated with good oral health and periodontal diseases were decreased over time, while the frequency and proportions of micro-organisms associated with caries and soft tissue infection were unaffected or increased. CONCLUSION: The results indicate that assisted oral hygiene care alone is not sufficient to regain an oral microbial flora associated with good oral health in dentate, dependent elderly residents.