Colonization Of Microorganisms Research Articles

Genome-scale model of Rothia mucilaginosa predicts gene essentialities and reveals metabolic capabilities.

Cystic fibrosis (CF), an inherited genetic disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator gene, results in sticky and thick mucosal fluids. This environment facilitates the colonization of various microorganisms, some of which can cause acute and chronic lung infections, while others may positively impact the disease. Rothia mucilaginosa, an oral commensal, is relatively abundant in the lungs of CF patients. Recent studies have unveiled its anti-inflammatory properties using in vitro three-dimensional lung epithelial cell cultures and in vivo mouse models relevant to chronic lung diseases. Apart from this, R. mucilaginosa has been associated with severe infections. However, its metabolic capabilities and genotype-phenotype relationships remain largely unknown. To gain insights into its cellular metabolism and genetic content, we developed the first manually curated genome-scale metabolic model, iRM23NL. Through growth kinetics and high-throughput phenotypic microarray testings, we defined its complete catabolic phenome. Subsequently, we assessed the model's effectiveness in accurately predicting growth behaviors and utilizing multiple substrates. We used constraint-based modeling techniques to formulate novel hypotheses that could expedite the development of antimicrobial strategies. More specifically, we detected putative essential genes and assessed their effect on metabolism under varying nutritional conditions. These predictions could offer novel potential antimicrobial targets without laborious large-scale screening of knockouts and mutant transposon libraries. Overall, iRM23NL demonstrates a solid capability to predict cellular phenotypes and holds immense potential as a valuable resource for accurate predictions in advancing antimicrobial therapies. Moreover, it can guide metabolic engineering to tailor R. mucilaginosa's metabolism for desired performance.IMPORTANCECystic fibrosis (CF) is a genetic disorder characterized by thick mucosal secretions, leading to chronic lung infections. Rothia mucilaginosa is a common bacterium found in various parts of the human body, acting as a normal part of the flora. In people with weakened immune systems, it can become an opportunistic pathogen, while it is prevalent and active in CF airways. Recent studies have highlighted its anti-inflammatory properties in the lower pulmonary system, indicating the intricate relationship between microbes and human health. Herein, we have developed the first manually curated metabolic model of R. mucilaginosa. Our study examined the previously unknown relationships between the bacterium's genotype and phenotype and identified essential genes that impact the metabolism under various conditions. With this, we opt for paving the way for developing new strategies in antimicrobial therapy and metabolic engineering, leading to enhanced therapeutic outcomes in cystic fibrosis and related conditions.

The potential of EGCG in modulating the oral-gut axis microbiota for treating inflammatory bowel disease

Inflammatory bowel disease (IBD) is a recurrent chronic intestinal disorder that includes ulcerative colitis (UC) and Crohn's disease (CD). Its pathogenesis involves intricate interactions between pathogenic microorganisms, native intestinal microorganisms, and the intestinal immune system via the oral-gut axis. The strong correlation observed between oral diseases and IBD indicates the potential involvement of oral pathogenic microorganisms in IBD development. Consequently, therapeutic strategies targeting the proliferation, translocation, intestinal colonization and exacerbated intestinal inflammation of oral microorganisms within the oral-gut axis may partially alleviate IBD. Tea consumption has been identified as a contributing factor in reducing IBD, with epigallocatechin gallate (EGCG) being the primary bioactive compound used for IBD treatment. However, the precise mechanism by which EGCG mediates microbial crosstalk within the oral-gut axis remains unclear. In this review, we provide a comprehensive overview of the diverse oral microorganisms implicated in the pathogenesis of IBD and elucidate their colonization pathways and mechanisms. Subsequently, we investigated the antibacterial properties of EGCG and its potential to attenuate microbial translocation and colonization in the gut, emphasizing its role in attenuating exacerbations of IBD. We also elucidated the toxic and side effects of EGCG. Finally, we discuss current strategies for enhancing EGCG bioavailability and propose novel multi-targeted nano-delivery systems for the more efficacious management of IBD. This review elucidates the role and feasibility of EGCG-mediated modulation of the oral-gut axis microbiota in the management of IBD, contributing to a better understanding of the mechanism of action of EGCG in the treatment of IBD and the development of prospective treatment strategies.

Bioreceptive Ceramic Surfaces: Material Experimentations for Responsible Research and Design Innovation in Circular Economy Transition and “Ecological Augmentation”

The world demands suitable design solutions to transition toward a sustainable production system. The concept of sustainability evolves with technology’s ability to understand and replicate nature’s logic. There is a growing need to move beyond punctual solutions towards more intricate and multi-stakeholder considerations, including preemptive assessments of impacts. This article discusses the outcomes of cross-disciplinary material experimentation at Saperi&Co Center, Sapienza University of Rome. This research focuses on enhancing ceramic surfaces through circular economy practices, making them receptive to microorganism colonization—known as bioreceptivity. Through an iterative and repetitive approach, inspired by Research Through Design and material experimentation, several experiments were carried out to study how the innovative use of organic waste in clay-based mixtures can promote bioreceptivity and the design of green surfaces for urban regeneration. The results advance our knowledge on the multiple parameters the designer must consider to transform inert surfaces such as ceramics into “ecological augmentation” devices. The article also aims to raise awareness of bioreceptivity as a practice to educate communities about a symbiotic relationship with nature, promote local economic development and circular production, and prompt reflection on cultural aspects arising from contemporary scientific and technological advancements in line with Responsible Research and Innovation (RRI) principles.

The Associations between Snack Intake and Cariogenic Oral Microorganism Colonization in Young Children of a Low Socioeconomic Status.

Cariogenic microorganisms are crucial pathogens contributing to the development of early childhood caries. Snacks provide fermentable carbohydrates, altering oral pH levels and potentially affecting microorganism colonization. However, the relationship between snack intake and cariogenic microorganisms like Candida and Streptococcus mutans in young children is still unclear. This study aimed to assess this association in a prospective underserved birth cohort. Data from children aged 12 to 24 months, including oral microbial assays and snack intake information, were analyzed. Sweet and non-sweet indices based on the cariogenic potential of 15 snacks/drinks were created. Mixed-effects models were used to assess the associations between sweet and non-sweet indices and S. mutans and Candida carriage. Random forest identified predictive factors of microorganism carriage. Higher non-sweet index scores were linked to increased S. mutans carriage in plaques (OR = 1.67, p = 0.01), potentially strengthening with age. Higher sweet index scores at 12 months were associated with increased Candida carriage, reversing at 24 months. Both indices were top predictors of S. mutans and Candida carriage. These findings underscore the associations between snack intake and cariogenic microorganism carriage and highlight the importance of dietary factors in oral health management for underserved young children with limited access to dental care and healthy foods.

Nanosilver-loaded and polysaccharide-based biomaterial for antibacterial activity - in combination with photobiomodulation for effective wound healing applications

Silver nanoparticles (AgNPs) are gaining attention for their use in wound healing and tissue engineering. Silver nanoparticles have been proven to effectively accelerate wound healing by killing Gram-positive and Gram-negative bacterial strains and controlling microorganism colonization. Polysaccharides are non-toxic, safe, inexpensive, and have good biocompatibility and biodegradability. Polysaccharides, such as chitosan and gum tragacanth, have positively impacted wound healing processes. Photobiomodulation (PBM) has been shown to enhance cell proliferation, activate lymphocytes, and increase phagocytosis in wound healing. A study synthesized and characterized Nanosilver (NS)-loaded chitosan and gum tragacanth-based biomaterial (CGT-NS) and evaluated its antimicrobial activity. The combined therapy of CGT-NS biomaterial and PBM irradiation at 830 nm in normal wounded cells showed no adverse effects on wound healing processes.

Genetic evidence strengthens the bidirectional connection between gut microbiota and Shigella infection: insights from a two-sample Mendelian randomization study.

In recent investigations, substantial strides have been made in the precise modulation of the gut microbiota to prevent and treat a myriad of diseases. Simultaneously, the pressing issue of widespread antibiotic resistance and multidrug resistance resulting from Shigella infections demands urgent attention. Several studies suggest that the antagonistic influence of the gut microbiota could serve as a novel avenue for impeding the colonization of pathogenic microorganisms or treating Shigella infections. However, conventional research methodologies encounter inherent challenges in identifying antagonistic microbial agents against Shigella, necessitating a comprehensive and in-depth analysis of the causal relationship between Shigella infections and the gut microbiota. Utilizing the aggregated summary statistics from Genome-Wide Association Studies (GWAS), we conducted Mendelian Randomization (MR) analyses encompassing 18,340 participants to explore the interplay between the gut microbiota and Shigella infections. This investigation also involved 83 cases of Shigella infection patients and 336,396 control subjects. In the positive strand of our findings, we initially performed a preliminary analysis using the Inverse Variance Weighting (IVW) method. Subsequently, we undertook sensitivity analyses to assess the robustness of the results, addressing confounding factors' influence. This involved employing the Leave-One-Out method and scrutinizing funnel plots to ensure the reliability of the MR analysis outcomes. Conclusively, a reverse MR analysis was carried out, employing the Wald ratio method due to the exposure of individual Single Nucleotide Polymorphisms (SNPs). This was undertaken to explore the plausible associations between Shigella infections and genetically predicted compositions of the gut microbiota. In this study, we employed 2,818 SNPs associated with 211 species of gut microbiota as instrumental variables (IVs). Through IVW analysis, our positive MR findings revealed a significant negative correlation between the occurrence of Shigella infections and the phylum Tenericutes (OR: 0.18, 95% CI: 0.04-0.74, p = 0.02), class Mollicutes (OR: 0.18, 95% CI: 0.04-0.74, p = 0.02), genus Intestinimonas (OR: 0.16, 95% CI: 0.04-0.63, p = 0.01), genus Gordonibacter (OR: 0.39, 95% CI: 0.16-0.93, p = 0.03), and genus Butyrivibrio (OR: 0.44, 95% CI: 0.23-0.87, p = 0.02). Conversely, a positive correlation was observed between the occurrence of Shigella infections and genus Sutterella (OR: 10.16, 95% CI: 1.87-55.13, p = 0.01) and genus Alistipes (OR: 12.24, 95% CI: 1.71-87.34, p = 0.01). In sensitivity analyses, utilizing MR-Egger regression analysis and MR Pleiotropy Residual Sum and Outlier (MR-PRESSO) detection, all outcomes demonstrated robust stability. Simultaneously, in the reverse MR analysis, Shigella infections resulted in an upregulation of four bacterial genera and a downregulation of three bacterial genera. In summation, the MR analysis outcomes corroborate the presence of bidirectional causal relationships between the gut microbiota and Shigella infections. This study not only unveils novel perspectives for the prevention and treatment of Shigella infections but also furnishes fresh insights into the mechanistic underpinnings of how the gut microbiota contributes to the pathogenesis of Shigella infections. Consequently, the established dual causal association holds promise for advancing our understanding and addressing the complexities inherent in the interplay between the gut microbiota and Shigella infections, thereby paving the way for innovative therapeutic interventions and preventive strategies in the realm of Shigella-related diseases.

The effect of tobacco leave pastes (Nicotiana tabacum L.) 50% concentration as a denture cleanser on the surface roughness of thermoplastic nylon

Microporosity of thermoplastic nylon can lead to increased surface roughness values. Surface roughness of thermoplastic nylon can facilitate colonization of microorganisms that can lead to denture stomatitis. The mechanical cleaning process of denture using an electric toothbrush and denture cleaning paste is considered effective for removing plaque and microorganisms attached. To reduce surface roughness, the use of natural materials such as tobacco leaves is considered beneficial because it can reduce the content of abrasive materials. This study aims to determine the effect of tobacco leaf paste as a denture cleanser on the surface roughness of thermoplastic nylon. This study using a laboratory experimental design with a post test only control group design involving 27 samples sized 60 x 10 x 2.5 mm which were divided into three groups including the brushing control group without paste, the brushing group with placebo paste, and the brushing group with 50% tobacco leaf paste (TLP). The results showed that tobacco leaf paste was considered effective as a thermoplastic nylon denture cleanser and had an effect on reducing surface roughness values with an average surface roughness value that was still acceptable to the oral cavity. In conclusion, 50% tobacco leaf paste is recommended as an effective denture cleanser and produces surface roughness values acceptable to the oral cavity.

Petroleum-contaminated soil bioremediation and microbial community succession induced by application of co-pyrolysis biochar amendment: An investigation of performances and mechanisms

This study aimed to remediate petroleum-contaminated soil using co-pyrolysis biochar derived from rice husk and cellulose. Rice husk and cellulose were mixed in various weight ratios (0:1, 1:0, 1:1, 1:3 and 3:1) and pyrolyzed under 500 °C. These biochar variants were labeled as R0C1, R1C0, R1C1, R1C3 and R3C1, respectively. Notably, the specific surface area and carbon content of the co- pyrolysis biochar increased, potentially promoting the growth and colonization of soil microorganisms. On the 60th day, the microbial control group achieved a 46.69% removal of pollutants, while the addition of R0C1, R1C0, R1C3, R1C1 and R3C1 resulted in removals of 70.56%, 67.01%, 67.62%, 68.74% and 67.30%, respectively. In contrast, the highest efficiency observed in the abiotic treatment group was only 24.12%. This suggested that the removal of petroleum pollutants was an outcome of the collaborative influence of co-pyrolysis biochar and soil microorganisms. Furthermore, the abundance of Proteobacteria, renowned for its petroleum degradation capability, obviously increased in the treatment group with the addition of co-pyrolysis biochar. This demonstrated that co-pyrolysis biochar could notably stimulate the growth of functionally associated microorganisms. This research confirmed the promising application of co-pyrolysis biochar in the remediation of petroleum-contaminated soil.

A main chain biodegradable polyurethane with anti-protein adsorption and anti-bacterial adhesion performances.

Biofilms are initially formed by substances such as proteins secreted by bacteria adhering to a surface. To achieve a durable antibacterial material, biodegradable dihydroxyl-terminated poly[(ethylene oxide)-co-(ethylene carbonate)] (PEOC(OH)2) with anti-protein adsorption properties was synthesized in this study. Further polycondensation of PEOC(OH)2 and isophorone diisocyanate (IPDI) led to biodegradable polyurethane (PEOC-PU) with PEOC as the soft segment. For comparison, polyurethanes with polyethylene glycol (PEG-PU) and polypropylene glycol (PPG-PU) as soft segments were also synthesized. The chemical structures of the polyurethanes were characterized by 1H NMR and FTIR. The biodegradation behavior of PEOC-PU promoted by lipase due to the presence of ethylene carbonate units was also studied. Their resistance to proteins was studied using quartz crystal microbalance with dissipation (QCM-D) and the results revealed that PEOC-PU exhibited excellent nonspecific resistance to proteins. The colonization of microorganisms on PU in the liquid culture medium was further examined and the results showed that PEOC-PU exhibited excellent antibacterial adhesion performance due to its protein resistance and biodegradation.

Bacterial profile of urinary tract infection among pregnant women: a systematic review

Urinary tract infection (UTI) is the infection and colonization of microorganisms in the urinary tract. Women carry a higher risk of being affected by UTI compared to males, especially during pregnancy due to physiological and hormonal changes. Appropriate and adequate management of UTI reduces the incidence of further maternal and fetal complications. Nonetheless, there is a growing concern regarding resistance to antibiotics among the bacteria causing UTIs in pregnant women. To identify the bacterial profile of UTIs during gestation by exploring the previous research conducted on this subject. A systematic online search was performed on scientific databases to obtain articles related to the current subject using search terms, including bacteria, profile, causative agent, sensitivity, resistance, symptomatic, pregnancy, gestation, and pregnant women. The articles of relevance were considered if they were original articles, written in the English language, available for full-text, and reporting bacterial profile of UTI during pregnancy. A total of eight articles were eligible and met the inclusion criteria. The studies were published between 2020 and 2023 and included a total number of 3,702 pregnant females from five different countries. The bacterial profile of UTI among pregnant women including symptomatic UTI, and resistance and sensitivity of bacteria to antibiotics varied between different regions. However, the causative agents of UTI displayed less variation as Escherichia coli and K.pneomniae were the major causative agents of UTI during pregnancy.

Fe/Fe3C nanoparticles in situ-doped with carbon nanofibers embedded in rGO as high-performance anode electrocatalysts of microbial fuel cells

The aerogel structure composed of NCNFs and rGO is conducive to the colonization and extracellular electron transport of microorganisms.

Occurrence of COVID-19 in cystic fibrosis patients: a review.

Cystic fibrosis (CF) is a genetic ailment caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. This autosomal recessive disorder is characterized by diverse pathobiological abnormalities, such as the disorder of CFTR channels in mucosal surfaces, caused by inadequate clearance of mucus and sputum, in addition to the malfunctioning of mucous organs. However, the primary motive of mortality in CF patients is pulmonary failure, which is attributed to the colonization of opportunistic microorganisms, formation of resistant biofilms, and a subsequent decline in lung characteristics. In December 2019, the World Health Organization (WHO) declared the outbreak of the radical coronavirus disease 2019 (COVID-19) as a worldwide public health crisis, which unexpectedly spread not only within China but also globally. Given that the respiration system is the primary target of the COVID-19 virus, it is crucial to investigate the impact of COVID-19 on the pathogenesis and mortality of CF patients, mainly in the context of acute respiratory distress syndrome (ARDS). Therefore, the goal of this review is to comprehensively review the present literature on the relationship between cystic fibrosis, COVID-19 contamination, and development of ARDS. Several investigations performed during the early stages of the virus outbreak have discovered unexpected findings regarding the occurrence and effectiveness of COVID-19 in individuals with CF. Contrary to initial expectancies, the rate of infection and the effectiveness of the virus in CF patients are lower than those in the overall population. This finding may be attributed to different factors, including the presence of thick mucus, social avoidance, using remedies that include azithromycin, the fairly younger age of CF patients, decreased presence of ACE-2 receptors, and the effect of CFTR channel disorder on the replication cycle and infectivity of the virus. However, it is important to notice that certain situations, which include undergoing a transplant, can also doubtlessly boost the susceptibility of CF patients to COVID-19. Furthermore, with an increase in age in CF patients, it is vital to take into account the prevalence of the SARS-CoV-2 virus in this population. Therefore, ordinary surveillance of CF patients is vital to evaluate and save the population from the capability of transmission of the virus given the various factors that contribute to the spread of the SARS-CoV-2 outbreak in this precise organization.

Preventing microbe colonization on avocado (Persea nubigena var. guatemalensis) through metabiotic treatment, a promising postharvest safety improvement.

Lactic acid bacteria (LAB) produce various metabolites (i.e. metabiotics) with inhibitory capacity towards harmful foodborne pathogens. This study aimed to design several antimicrobial formulations based on metabiotics obtained from different native LAB species (Lactobacillus pentosus UTNGt5, Lactococcus lactis UTNGt28, and Weissella cibaria UTNGt21O) and to detect the possible mode of action towards two multidrug resistant Staphylococcus spp. strains isolated from avocado (Persea nubigena var. guatemalensis) fruits. Additionally, the formulation with the highest inhibitory activity was tested ex vitro on avocados at the immature (firm) ripeness stage to evaluate their effect on microorganisms' growth and fruit quality attributes post-harvest. Out of the top five formulations showing the highest bactericidal effect in vitro at their minimum inhibitory concentration (1 x MIC) on both Staphylococcus spp. targets one candidate annotated P11 (consisting of UTNGt21O and UTNGt28; 1:3, v/v) was selected. Co-cultivation of Staphylococcus strains with P11 formulation results in cell viability reduction by 98%, by impairing the integrity of the cell membrane inducing cytoplasm molecule content leakage, protein profile changes, and finally bacterial death. Even though the total coliforms, Staphylococcus spp., Enterobacter spp., molds, and yeasts counts were not fully eliminated by day 13 of storage, a statistically significant reduction (p < 0.05) in viable cell counts were observed by day 8 upon the P11 treatment compared with non-treated control (C) and treated with a commercial disinfectant (T1) samples, suggesting that P11 formulation inhibited microbial colonization during storage. Likewise, no visible dark spots were observed on the mesocarp (pulp) upon the treatment with P11, whereas T1 and C fruits showed greater dark spots on the pulp as indicative of damage. The quality attributes, such as pH, total soluble solids, total titratable acidity, antioxidant capacity, and total polyphenol content, were not affected by the treatment. Principal Component Analysis (PCA) conducted on these five variables showed a clear separation of samples according to the maturity stage regardless of the treatment. These results suggest that the active metabolites from LAB strains might create a barrier between the exocarp and mesocarp, inhibiting the microorganisms colonization, reducing fruit damage, and lengthening the fruit quality and safety after harvest.

Revealing the characteristics of biofilms on different polypropylene plastic products: Comparison between disposable masks and takeaway boxes

The increasingly severe plastic pollution issue was intensified by the enormous plastic emissions into ecosystems during the Covid-19 pandemic. Plastic wastes entering the environment were swiftly exposed to microorganisms and colonized by biofilms, and the plastic-biofilm combined effects further influenced the ecosystem. However, the non-woven structure of disposable masks discarded carelessly during the COVID-19 pandemic was different from those of plastics with flat surface. To reveal the potential effects of plastic structure on colonized biofilms, white disposable surgical masks (DM) and transparent takeaway boxes (TB), both made of polyethylene, were selected for the incubation of organic conditioning films and biofilms. The results indicated that the non-woven structure of disposable mask was destroyed by the influence of water infiltration and biofilm colonization. The influence of surface structure on conditioning films led to a relatively higher proportion of tryptophan-like substances on DM than those on TB samples. Therefore, biofilms with significantly higher microbial biomass and carbon metabolic capacity were formed on DM than those on TB samples owing to the combined effects of their differences in surface structure and conditioning films. Moreover, abundant functional microorganisms associated with stress tolerance, carbon metabolism and biofilm formation were observed in biofilms on disposable mask. Combining with the results of partial least squares regression analysis, the selective colonization of functional microorganisms on disposable masks with uneven surface longitudinal fluctuation was revealed. Although the predicted functions of biofilms on disposable masks and takeaway boxes showed more similarity to each other than to those of free-living aquatic microorganisms owing to the existence of the plastisphere, biofilms on disposable masks may potentially trigger environmental risks different from those of takeaway boxes by unique carbon metabolism and abundant biomass.

An overview of potential algae-derived bioactive compounds against urease-positive microorganisms

Urease (EC 3.5.1.5) is a virulence factor found in various microorganisms, including Helicobacter pylori, Proteus mirabilis, and Klebsiella pneumoniae. As a nickel-containing enzyme, urease plays the most significant role in the colonization and maintenance of microorganisms in host organisms, making it a potential target for the treatment of resistant urease-positive infections. Notably, urease positive pathogens pose significant public health concerns due to their association with gastric ulcers, gastritis, kidney stones, urinary tract infections, and other diseases. This review focuses on exploring ureases' structure and catalytic properties, with a special emphasis on H. pylori. Moreover, the other virulence factors of H. pylori, including flagella, outer membrane proteins, accessory proteins, cytotoxin-associated gene A (CagA), and vacuolating cytotoxin A (VacA), are discussed. Also, the adaptive mechanism of H. pylori, relying on urease to survive the acidic gastric environment, is explored, along with the detrimental effects of ammonium on gastric epithelial cells produced by urease. Urease inhibitors have garnered interest as potential therapeutic agents to reduce the complications of urease-positive microorganisms. In this context, natural bioactive compounds gain interest in developing alternative therapeutic strategies. Algae are rich in several biochemical compounds with various biological attributes, particularly antibacterial and anti-inflammatory properties. Numerous studies have explored to identify the novel perspective anti-H. pylori agents from different algae species. This review also provides insights into the potential of algal bioactive compounds as effective agents against urease-positive infections. The significance of exploring new therapeutic strategies to address H. pylori-induced diseases is highlighted, considering the emergence of antibiotic resistance and the need for improved therapeutic approaches.

A laboratory ice machine as a cold oligotrophic artificial microbial niche for biodiscovery

Microorganisms are ubiquitously distributed in nature and usually appear as biofilms attached to a variety of surfaces. Here, we report the development of a thick biofilm in the drain pipe of several standard laboratory ice machines, and we describe and characterise, through culture-dependent and -independent techniques, the composition of this oligotrophic microbial community. By using culturomics, 25 different microbial strains were isolated and taxonomically identified. The 16S rRNA high-throughput sequencing analysis revealed that Bacteroidota and Proteobacteria were the most abundant bacterial phyla in the sample, followed by Acidobacteriota and Planctomycetota, while ITS high-throughput sequencing uncovered the fungal community was clearly dominated by the presence of a yet-unidentified genus from the Didymellaceae family. Alpha and beta diversity comparisons of the ice machine microbial community against that of other similar cold oligotrophic and/or artificial environments revealed a low similarity between samples, highlighting the ice machine could be considered a cold and oligotrophic niche with a unique selective pressure for colonisation of particular microorganisms. The recovery and analysis of high-quality metagenome-assembled genomes (MAGs) yielded a strikingly high rate of new species. The functional profiling of the metagenome sequences uncovered the presence of proteins involved in extracellular polymeric substance (EPS) and fimbriae biosynthesis and also allowed us to detect the key proteins involved in the cold adaptation mechanisms and oligotrophic metabolic pathways. The metabolic functions in the recovered MAGs confirmed that all MAGs have the genes involved in psychrophilic protein biosynthesis. In addition, the highest number of genes for EPS biosynthesis was presented in MAGs associated with the genus Sphingomonas, which was also recovered by culture-based method. Further, the MAGs with the highest potential gene number for oligotrophic protein production were closely affiliated with the genera Chryseoglobus and Mycobacterium. Our results reveal the surprising potential of a cold oligotrophic microecosystem within a machine as a source of new microbial taxa and provide the scientific community with clues about which microorganisms are able to colonise this ecological niche and what physiological mechanisms they develop. These results pave the way to understand how and why certain microorganisms can colonise similar anthropogenic environments.

Metabolic diversity shapes vegetation-enhanced methane oxidation in landfill covers: Multi-omics study of rhizosphere microorganisms

Vegetation root exudates have the ability to shape soil microbial community structures, thereby enhancing CH4 bio-oxidation capacity in landfill cover systems. In this study, the CH4 oxidation capacity of indigenous vegetation rhizosphere microorganisms within operational landfill covers in Chongqing, China, was investigated for the first time, with the objective of identifying suitable plant candidates for CH4 mitigation initiatives within landfill cover systems. Furthermore, a multi-omics methodology was employed to explore microbial community structures and metabolic variances within the rhizospheric environment of diverse vegetation types. The primary aim was to elucidate the fundamental factors contributing to divergent CH4 oxidation capacities observed in rhizosphere soils. The findings demonstrated that herbaceous vegetation predominated in landfill covers. Notably, Rumex acetosa exhibited the highest CH4 oxidation capacity in the rhizosphere soil, approximately 20 times greater than that in non-rhizosphere soil. Root exudates played a crucial role in inducing the colonization of CH4-oxidizing functional microorganisms in the rhizosphere, subsequently prompting the development of specific metabolic pathways. This process, in turn, enhanced the functional activity of the microorganisms while concurrently bolstering their tolerance to microbial pollutants. Consequently, the addition of substances like Limonexic acid strengthened the CH4 bio-oxidation process, thereby underscoring the suitability of Rumex acetosa and similar vegetation species as preferred choices for landfill cover vegetation restoration.

Effectiveness of the Topical Application of 4% Chlorhexidine on Umbilical Cord Bacterial Colonization – A Non-Randomized Control Study

Newborns have the highest risk of death in the first 4 weeks of their life. Umbilical cord of a child is an important site for microorganism colonization and also forms a portal of entry for invasive pathogens. This study focuses on the bacterial colonization with 2 separate cord care regimens: dry cord and 4% chlorhexidine care group. This is a randomized control time-bound study conducted at a tertiary health care centre in Mangalore. A total of 144 newborns fulfilling the inclusion criteria were included and then divided randomly into two groups: dry cord care and 4% chlorhexidine. Two swabs were collected, baseline swab (swab 1) within 3 hours of birth and second swab (swab 2) at 120± 10 hours of birth and these samples were cultured for gram negative and positive organisms. Results were evaluvated with Chi-Square test. Out of 144 samples, in 115 showed no growth at the baseline and only 29 showed growth. In the dry cord care group, 38.9% showed growth of microorganism in comparison with chlorhexidine group which was 1.4% in swab 1 (baseline) and in swab 2, 87.5% in dry cord care group and 18.1% in chlrohexidine group in swab 2 respectively. It was observed that methicilin susceptible Staphylococcus aureus (MSSA) and methicillin resistant Staphylococcus aureus (MRSA) were the most common microorganisms isolated with others being Pseudomonas species, coagulase-negative Staphylococci (CoNS), Enterobacter species and Citrobacter species. Use of 4% chlorhexidine is effective in reducing colonization of bacteria and infection in comparison with dry cord care method. Therefore, decontamination of the umbilical cord with 4% of chlorhexidine should be recommended in a newborn child. However, both cord care methods did not lead to any infections.

Differences of airborne and mural microorganisms in a 1,500-year-old Xu Xianxiu's Tomb, Taiyuan, China.

Microbial colonization represents one of the main threats to the conservation of subterranean cultural heritage sites. Recently, the microbial colonization on murals in tombs has gradually attracted attention. In this study, a total of 33 samples, including 27 aerosol samples and 6 mural painting samples, were collected from different sites of Xu Xianxiu's Tomb and analyzed using culture-dependent methods. We compared the diversities of culturable bacteria and fungi isolated from the air and murals and explored the potential impacts of microorganisms on the biodeterioration of the murals. Phylogenetic analyses revealed that the culturable bacteria belonged to Bacillus, Microbacterium, Lysobacter and Arthrobacter. And the most of fungal belonged to the Penicillium, Cladosporium and Aspergillus genera. The composition and structure of airborne bacteria and fungi outside the tomb were both significantly different from that inside the tomb. The variation trends of airborne bacterial and fungal concentrations at different sampling sites were remarkably similar. Bacillus frigoritolerans, Bacillus halotolerans, Bacillus safensis, Exiguobacterium mexicanum, Microbacterium trichothecenolyticum, and Micrococcus yunnanensis were bacterial species commonly isolated from both the mural and air environments. Fungal species commonly isolated from aerosol samples and mural painting samples were Alternaria alternata, Cladosporium cladosporioides, Penicillium brevicompactum, and Peyronellaea glomerata. The prediction of the ecological functions of the bacteria revealed that chemoheterotrophy or aerobic_chemoheterotrophy accounted for substantial relative proportions in all sample types. These results suggest that the aerosol circulation between the inside and outside environments of the tomb was weak and that the outside environment had yet to have an impact on the air microbial community inside the tomb. Selective colonization of microorganisms, which is mediated by interaction between microorganisms and special microenvironmental factors, is an important reason for the biodeterioration of murals.

OTITIS EXTERNA DUE TO COMPLICATION OF OTODECTES CYNOTIS, BACTERIA, AND MALASSEZIA SP. ACCOMPANIED BY SCABIOSIS IN DOMESTIC CAT

Otitis externa is an inflammatory state of the external ear canal due to the colonization of microorganisms (bacteria, fungi, or parasites). Scabiosis in cats is a highly contagious disease caused by the Notoedres cati mite. The purpose of this article is to provide information on the diagnosis, treatment, and therapeutic evaluation of otitis externa with scabiosis in a local cat. The case animal was a 2-year-old female Oren, weighing 2.75 kg and with orange, black, and white hair. The cat was brought to the Teaching Animal Hospital, Faculty of Veterinary Medicine, Udayana University with complaints of frequent scratching of the right and left ears since 1 month ago. On physical examination, dark brown cerumen was found in the right and left ear canals. In the supporting examination, ear swab found Otodectes cynotis mite cytology ear cerumen observed the presence of bacteria in the form of cocci and bacilli, and Malassezia sp. While in the examination of skin scrapings found Notoedres cati mite. Based on anamnesis, clinical examination and supporting examination, the case cat was diagnosed with bilateral otitis externa and scabiosis with a prognosis of fausta. For the treatment of otitis, the therapy given was topical treatment using antiparasitic permethrine, antibiotic neomycin sulfate, antifungal nystatin and anti-inflammatory triamnicolone acetonide given once a day for 7 days. For the treatment of scabiosis, the therapy given is Ivermectin injection at a dose of 0.3 mg/kg BW subcutaneously twice administered at 14-day intervals. As symptomatic therapy, diphenhydramine was given at a dose of 1 mg/kg BW intramuscularly, followed by diphenhydramine HCL orally at a dose of 2 mg/kg BW given twice a day for 7 days as an antihistamine to treat pruritus. Topical therapy was also given by bathing with sulfur soap twice a week for two weeks. Evaluation was carried out on day 10 where the case cat showed a continuously improving condition characterized by the case cat rarely scratching the ears, the crusts on the skin had begun to thin, and the parts that were initially alopecia had begun to grow hair.