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Current Research in Microbial Sciences Dec 2021The proteomics and transcriptomic analysis of strain AS2 was carried out through 2D gel electrophoresis and RT-PCR. Seven protein spots were selected randomly from the...
The proteomics and transcriptomic analysis of strain AS2 was carried out through 2D gel electrophoresis and RT-PCR. Seven protein spots were selected randomly from the gel and identified through mass spectrometry. Four proteins including putative metal-dependent hydrolase TatD, thioredoxin reductase, DNA-directed RNA polymerase subunit alpha and chaperone protein DnaK were upregulated while superoxide dismutase [Mn], 3-oxoacyl-[acyl-carrier-protein] reductase FabG, and putative alkyl/aryl-sulfatase YjcS were down-regulated under arsenite stress. No significant difference was observed in gene expression analysis in the presence and absence of arsenite. The optimum arsenite processing ability was determined at 37°C (90%) and at pH 7 (92%). The maximum metal processing ability was determined at 250 mM arsenite/L (90%) while the minimum was estimated at 1250 mM arsenite/L (42%). The maximum arsenite removal ability of strain AS2 determined after 8 days was 68 and 82% from wastewater and distilled water, and the organism can be a good bioresource for green chemistry to eradicate environmental arsenite.
PubMed: 34841312
DOI: 10.1016/j.crmicr.2021.100020 -
Access Microbiology 2023Dormant bacterial cells do not divide and are not immediately culturable, but they persist in a state of low metabolic activity, a physiological state having clinical...
Dormant bacterial cells do not divide and are not immediately culturable, but they persist in a state of low metabolic activity, a physiological state having clinical relevance, for instance in latent tuberculosis. Resuscitation-promoting factors (Rpfs) are proteins that act as signalling molecules mediating growth and replication. In this study we aimed to test the effect of Rpfs from on the number and diversity of cultured bacteria using insect and soil samples, and to examine if the increase in culturability could be reproduced with the putative reaction product of Rpf, 1,6-anhydro--acetylmuramic acid (1,6-anhydro-MurNAc). The gene from was amplified and cloned into a pET21b expression vector and the protein was expressed in BL21(DE3) cells and purified by affinity chromatography using a hexa-histidine tag. 1,6-Anhydro-MurNAc was prepared using reported chemical synthesis methods. Recombinant Rpf protein or 1,6-anhydro-MurNAc were added to R2A cultivation media, and their effect on the culturability of bacteria from eight environmental samples including four cockroach guts and four soils was examined. Colony-forming units, 16S rRNA gene copies and Illumina amplicon sequencing of the 16S rRNA gene were measured for all eight samples subjected to three different treatments: Rpf, 1,6-anhydro-MurNAc or blank control. Both Rpf and 1,6-anhydro-MurNAc increased the number of colony-forming units and of 16S rRNA gene copies across the samples although the protein was more effective. The Rpf and 1,6-anhydro-MurNAc promoted the cultivation of a diverse set of bacteria and in particular certain clades of the phyla and . This study opens the path for improved cultivation strategies aiming to isolate and study yet undescribed living bacterial organisms.
PubMed: 37841103
DOI: 10.1099/acmi.0.000647.v4 -
Microorganisms Jun 2020Various microbial pathogens have been found in ticks such as . However, most studies assessed tick microbiomes without prior decontamination of the tick surface, which...
Various microbial pathogens have been found in ticks such as . However, most studies assessed tick microbiomes without prior decontamination of the tick surface, which may alter the results and mislead conclusions regarding the composition of the tick-borne microbiome. The aim of this study was to test four different decontamination methods, namely (i.) 70% ethanol, (ii.) DNA Away, (iii.) 5% sodium hypochlorite and (iv.) Reactive Skin Decontamination Lotion (RSDL), which have been previously reported for tick surface and animal or human skin decontamination. To test the efficiency of decontamination, we contaminated each tick with a defined mixture of , , , dog saliva and human sweat. No contamination was used as a negative control, and for a positive control, a no decontamination strategy was carried out. After nucleic acid extraction, the recovery rate of contaminants was determined for RNA and DNA samples by qPCR and tick-borne microbiome analyses by bacterial 16S rRNA and 16S rRNA gene amplicon sequencing. Ticks treated with 5% sodium hypochlorite revealed the lowest number of contaminants followed by DNA Away, RSDL and 70% ethanol. Moreover, tick microbiomes after 5% sodium hypochlorite decontamination clustered with negative controls. Therefore, the efficiency of decontamination was optimal with 5% sodium hypochlorite and is recommended for upcoming studies to address the unbiased detection of tick-borne pathogens.
PubMed: 32630152
DOI: 10.3390/microorganisms8070987 -
Iranian Biomedical Journal Jan 2023Lysozyme is a part of human and animal noncellular immunity. The regulation of its activity by hormones is poorly studied. The aim of this study was to test the in vitro...
BACKGROUND
Lysozyme is a part of human and animal noncellular immunity. The regulation of its activity by hormones is poorly studied. The aim of this study was to test the in vitro activity of lysozyme in the presence of catecholamines, natriuretic hormones, and estradiol (E2).
METHODS
Hormones were incubated with lysozyme, and the activity of lysozome was further determined using a test culture of Micrococcus luteus in the early exponential growth stage. The activity of lysozyme was assessed based on the rate of change in the OD of the test culture. Molecular docking was performed using SwissDock server http://www.swissdock.ch/docking), and molecular structures were further analyzed and visualized in the UCSF Chimera 1.15rc software.
RESULTS
According to the results, epinephrine and norepinephrine increased lysozyme activity up to 180% compared to the hormone-free enzyme. Changing the pH of the medium from 6.3 to 5.5, increased the lysozyme activity in the presence of E2 up to 150-200 %. The results also showed that exposure to hormones could modify lysozyme ctivity, and this effect depends on the temperature and pH value. The molecular docking revealed a decrease in the activation energy of the active site of enzyme during the interaction of catecholamines with the amino acid residues, asp52 and glu35 of the active site.
CONCLUSION
Our findings demonstrate an additional mechanism for the involvement of lysozyme in humoral regulation of nonspecific immunity with respect to human pathogenic microflora and bacterial skin commensals by direct modulation of its activity using human hormones.
Topics: Animals; Humans; Molecular Docking Simulation; Muramidase; Amino Acids; Temperature; Catecholamines
PubMed: 36624688
DOI: 10.52547/ibj.3614 -
Pharmaceuticals (Basel, Switzerland) Oct 2023The aim of this work was to provide an overview of available information on the antibacterial and antifungal properties of extracts. A literature search of Scopus,... (Review)
Review
The aim of this work was to provide an overview of available information on the antibacterial and antifungal properties of extracts. A literature search of Scopus, PubMed/Medline, and Google Scholar for peer-reviewed articles published between January 2000 and June 2023 was undertaken. A total of 23 studies were eligible for inclusion in this review. Significant variation of antimicrobial activity depending on the tested species and strains, type of extract solvent, or plant organs utilized for the extract preparation was found. extracts were active against both Gram-positive and Gram-negative bacteria and showed antimycotic effects against the fungi of and and the dermatophytes spp. Greater susceptibility of Gram-positive than Gram-negative bacteria to fireweed extracts was found. A strong antibacterial effect was recorded for , , , , , , and including multi-drug resistant strains. extract might find practical application as an antimicrobial in wound healing, components of cosmetic products for human and animals, or as food preservatives.
PubMed: 37895890
DOI: 10.3390/ph16101419 -
Journal, Genetic Engineering &... Dec 2023Lipases have emerged as essential biocatalysts, having the ability to contribute to a wide range of industrial applications. Microbial lipases have garnered significant...
BACKGROUND
Lipases have emerged as essential biocatalysts, having the ability to contribute to a wide range of industrial applications. Microbial lipases have garnered significant industrial attention due to their stability, selectivity, and broad substrate specificity. In the previous study, a unique lipolytic bacterium (Micrococcus luteus EMP48-D) was isolated from tempeh. It turns out the bacteria produce an acidic lipase, which is important in biodiesel production. Our main objectives were to clone the acidic lipase and investigate its potential in biodiesel production.
RESULT
In this study, the gene encoding a lipase from M. luteus EMP48-D was cloned and expressed heterologously in Escherichia coli. To our knowledge, this is the first attempt at the cloning and expression of the lipase gene from Micrococcus luteus. The amino acid sequence was deduced from the nucleotide sequence (1356 bp) corresponded to a protein of 451 amino acid residues with a molecular weight of about 40 kDa. The presence of a signal peptide suggested that the protein was extracellular. A sequence analysis revealed that the protein had a lipase-specific Gly-X-Ser-X-Gly motif. The enzyme was identified as an acidic lipase with a pH preference of 5.0. Fatty acid preferences for enzyme activities were C8 and C12 (p-nitrophenyl esters), with optimum temperatures at 30-40 °C and still remaining active at 80°C. The enzyme was also shown to convert up to 70% of the substrate into fatty acid methyl ester.
CONCLUSION
The enzyme was a novel acidic lipase that demonstrated both hydrolytic and transesterification reactions. It appeared particularly promising for the synthesis of biodiesel as this enzyme's catalytic reaction was optimum at low temperatures and was still active at high temperatures.
PubMed: 38038870
DOI: 10.1186/s43141-023-00611-9 -
BMC Genomics Feb 2021Micrococcus luteus is a group of actinobacteria that is widely used in biotechnology and is being thought as an emerging nosocomial pathogen. With one of the smallest...
BACKGROUND
Micrococcus luteus is a group of actinobacteria that is widely used in biotechnology and is being thought as an emerging nosocomial pathogen. With one of the smallest genomes of free-living actinobacteria, it is found in a wide range of environments, but intraspecies genetic diversity and adaptation strategies to various environments remain unclear. Here, comparative genomics, phylogenomics, and genome-wide association studies were used to investigate the genomic diversity, evolutionary history, and the potential ecological differentiation of the species.
RESULTS
High-quality genomes of 66 M. luteus strains were downloaded from the NCBI GenBank database and core and pan-genome analysis revealed a considerable intraspecies heterogeneity. Phylogenomic analysis, gene content comparison, and average nucleotide identity calculation consistently indicated that the species has diverged into three well-differentiated clades. Population structure analysis further suggested the existence of an unknown ancestor or the fourth, yet unsampled, clade. Reconstruction of gene gain/loss events along the evolutionary history revealed both early events that contributed to the inter-clade divergence and recent events leading to the intra-clade diversity. We also found convincing evidence that recombination has played a key role in the evolutionary process of the species, with upto two-thirds of the core genes having been affected by recombination. Furthermore, distribution of mammal-associated strains (including pathogens) on the phylogenetic tree suggested that the last common ancestor had a free-living lifestyle, and a few recently diverged lineages have developed a mammal-associated lifestyle separately. Consistently, genome-wide association analysis revealed that mammal-associated strains from different lineages shared genes functionally relevant to the host-associated lifestyle, indicating a recent ecological adaption to the new host-associated habitats.
CONCLUSIONS
These results revealed high intraspecies genomic diversity of M. luteus and highlighted that gene gain/loss events and extensive recombination events played key roles in the genome evolution. Our study also indicated that, as a free-living species, some lineages have recently developed or are developing a mammal-associated lifestyle. This study provides insights into the mechanisms that drive the genome evolution and adaption to various environments of a bacterial species.
Topics: Animals; Evolution, Molecular; Genetic Variation; Genome, Bacterial; Genome-Wide Association Study; Genomics; Micrococcus luteus; Phylogeny; Recombination, Genetic
PubMed: 33602135
DOI: 10.1186/s12864-021-07432-5 -
Molecules (Basel, Switzerland) May 2021Due to the health-promoting properties of elderberry fruits, which result from their rich chemical composition, this raw material is widely used in herbal medicine and...
Due to the health-promoting properties of elderberry fruits, which result from their rich chemical composition, this raw material is widely used in herbal medicine and the food industry. The aim of the study was to demonstrate the antibacterial activity of the elderberry fruit extracts. The research showed that the content of phenolic acids and flavonoids in the extracts determined their antibacterial activity. The research showed that the content of phenolic acids and flavonoids in the extracts determined their antibacterial activity. The following phenolic acids were predominant: chlorogenic acid, sinapic acid, and t-cinnamic acid. Their average content was, respectively, 139.09, 72.84, 51.29 mg/g extract. Rutin and quercetin (their average content was 1105.39 and 306.6 mg/g extract, respectively) were the dominant flavonoids. The research showed that the elderberry polyphenol extracts exhibited activity against selected strains of bacteria within the concentration range of 0.5-0.05%. The following bacteria were the most sensitive to the extracts: , , , and . Of the compounds under analysis, apigenin, kaempferol and ferulic, protocatechuic, and p-coumarin acids had the greatest influence on the high antibacterial activity of elderberry extracts. The results of the microbiological and chemical analyses of the composition of the extracts were analyzed statistically to indicate the bioactive compounds of the greatest antimicrobial significance.
Topics: Anti-Infective Agents; Antioxidants; Bacteria; Benzothiazoles; Carboxylic Acids; Flavonoids; Microbial Sensitivity Tests; Pigments, Biological; Plant Extracts; Polyphenols; Sambucus nigra; Sulfonic Acids
PubMed: 34068909
DOI: 10.3390/molecules26102910 -
Pharmaceuticals (Basel, Switzerland) Feb 2023Seborrheic dermatitis (SD) is the most prevalent dermatological disease, occurring in up to 50% of newborns, children, and adults around the world. The antibacterial and...
Seborrheic dermatitis (SD) is the most prevalent dermatological disease, occurring in up to 50% of newborns, children, and adults around the world. The antibacterial and antifungal resistance contributed to the search for new natural substances and the development of a novel substance based on () leaf oil (TTO), 1,8-cineole (eucalyptol), and α-(-)-bisabolol. Thus, this work aimed to determine the chemical composition of the novel plant-based substance and to evaluate its antimicrobial activity against standard microorganisms involved in the pathogenesis of SD. Moreover, the chemical composition of the substance was analyzed by gas chromatography coupled with mass spectrometry (GC/MS). (), (), (), and () were used for antimicrobial and antifungal assays by means of the broth microdilution method to determine the minimal inhibitory concentration (MIC). Finally, the substance's ability to inhibit () was evaluated. Eighteen compounds from different chemical groups were identified by GC/MS. The major biologically active compounds of the substance were terpinen-4-ol (20.88%), 1,8-cineole (22.28%), (-)-α-bisabolol (25.73%), and o-cymene (8.16%). The results showed that the substance has a synergistic antimicrobial and antifungal activity, while and strains were the most susceptible. Furthermore, the substance inhibited , which is a main pathogen involved in the pathogenesis of SD and clinical manifestations. It can be concluded that the novel plant-based substance has a promising potential against and scalp commensal bacteria and may be helpful for the development of new drugs for treatment of dandruff and SD.
PubMed: 36986428
DOI: 10.3390/ph16030328 -
Clinical Characteristics of Patients with Bloodstream Infection in a Chinese Tertiary-Care Hospital.Polish Journal of Microbiology Sep 2021Few pieces of research have focused on bloodstream infection (BSI) because of its low incidence; hence data is needed to illustrate this uncommon infection. This study...
Few pieces of research have focused on bloodstream infection (BSI) because of its low incidence; hence data is needed to illustrate this uncommon infection. This study aimed to explore the clinical characteristics of patients with BSI. From January 2010 to December 2019, inpatients that met the criteria for BSI were included in this study. Data was collected by reviewing electronic records. Ninety-seven patients were enrolled in this study. Sixty-three percent of the patients have a higher neutrophil percentage (NEUT%). The average blood C-reactive protein (CRP) concentration was 5.5 ± 6.4 mg/dl. 48.5% of the patients had malignancy, and 40.2% underwent invasive surgeries. Linezolid was found to have the largest average diameter of the inhibition zone (36 mm), while erythromycin was found to have the smallest average zone diameter (15 mm). However, some strains had a potentially broad antimicrobial resistance spectrum. Cephalosporins (59.2%) and quinolones (21.4%) were the most commonly used antibiotics for empirical therapies. In conclusion, BSI mainly happens in immunocompromised patients or those with former invasive surgeries or indwelling catheters. strains are less responsive to erythromycin. Cephalosporins and quinolones are effective empirical antibiotics for BSI; however, vancomycin and teicoplanin should be considered for potentially broadly drug-resistant strains.
Topics: China; Gram-Positive Bacterial Infections; Humans; Micrococcus luteus; Sepsis; Tertiary Care Centers
PubMed: 34584526
DOI: 10.33073/pjm-2021-030