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Molecules (Basel, Switzerland) Sep 2021Due to the strong drug resistance of (), the inhibition effects of conventional disinfectants and antibiotics are not obvious. Juglone extracted from discarded walnut...
Due to the strong drug resistance of (), the inhibition effects of conventional disinfectants and antibiotics are not obvious. Juglone extracted from discarded walnut husk, as a kind of plant-derived antimicrobial agent, has the advantages of naturalness, high efficiency, and low residue, with a potential role in the inhibition of . This study elucidated the inhibitory effect of juglone on the growth of plankton and the formation of biofilm. The results showed that juglone (35 μg/mL) had an irreversible inhibitory effect on colony formation (about 10 CFU/mL). The integrity and permeability of the cell membrane were effectively destroyed, accompanied by disorder of the membrane permeability, mass leakage of the cytoplasm, and ATP consumption. Further studies manifested that juglone could induce the abnormal accumulation of ROS in cells and block the formation of the cell membrane. In addition, RT-qPCR showed that juglone could effectively block the expression of five virulence genes and two genes involved in the production of extracellular polymers, thereby reducing the toxicity and infection of and preventing the production of extracellular polymers. This study can provide support for the innovation of antibacterial technology toward in food.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Biofilms; Cell Membrane; Cytotoxins; Gene Expression Regulation, Bacterial; Naphthoquinones; Polymers; Pseudomonas aeruginosa; Quorum Sensing; Virulence
PubMed: 34641398
DOI: 10.3390/molecules26195854 -
Microbiology (Reading, England) Mar 2022The fungal pathogen is frequently cultured from the sputum of cystic fibrosis (CF) patients along with the bacterium secretes a range of secondary metabolites, and one...
The fungal pathogen is frequently cultured from the sputum of cystic fibrosis (CF) patients along with the bacterium secretes a range of secondary metabolites, and one of these, gliotoxin, has inhibitory effects on the host immune response. The effect of culture filtrate (CuF) on fungal growth and gliotoxin production was investigated. Exposure of hyphae to cells induced increased production of gliotoxin and a decrease in fungal growth. In contrast, exposure of hyphae to CuF led to increased growth and decreased gliotoxin production. Quantitative proteomic analysis was used to characterize the proteomic response of upon exposure to CuF. Changes in the profile of proteins involved in secondary metabolite biosynthesis (e.g. gliotoxin, fumagillin, pseurotin A), and changes to the abundance of proteins involved in oxidative stress (e.g. formate dehydrogenase) and detoxification (e.g. thioredoxin reductase) were observed, indicating that the bacterial secretome had a profound effect on the fungal proteome. Alterations in the abundance of proteins involved in detoxification and oxidative stress highlight the ability of to differentially regulate protein synthesis in response to environmental stresses imposed by competitors such as . Such responses may ultimately have serious detrimental effects on the host.
Topics: Aspergillus fumigatus; Humans; Proteome; Proteomics; Pseudomonas aeruginosa; Secretome
PubMed: 35333152
DOI: 10.1099/mic.0.001164 -
Scientific Reports Jun 2021Hospital wastewater (HWW) harbours diverse microbial species and a miscellany of genome that would facilitate the emergence of novel pathogen upon genome integration...
Hospital wastewater (HWW) harbours diverse microbial species and a miscellany of genome that would facilitate the emergence of novel pathogen upon genome integration that manifests novel traits in infectious pathogens. The study aimed to determine the antibiogram, and virulence signatures of Pseudomonas aeruginosa (P. aeruginosa) recovered from selected agrestic hospital effluents in Eastern Cape, South Africa. Thirty-six (36) wastewater samples were collected from selected hospital drains between February 2018 and April 2018, processed and analyzed by culture-dependent methods for the isolation of P. aeruginosa. The identity confirmation of isolates was achieved by amplification of oprl and oprL genes. Antibiogram was done using standard disk diffusion technique of Kirby-Bauer as approved by CLSI 2018 guidelines. Virulence signatures (lasA, lasB, toxA, popB) among isolates were analysed using polymerase chain reaction. A total of 54 P. aeruginosa isolates were confirmed by amplification of oprl and oprL genes in the hospital wastewater effluent samples. The isolates showed a 100% susceptibility to gentamicin, amikacin and imipenem antimicrobial agents. Ceftazidime recorded the most resistance (63%) against the isolates studied. Other antibiotics had a resistance range of 7% and 35%. The MAR index among the isolates revealed a range of 0.23 and 0.38. ToxA virulence gene was detected in all isolates while popB, lasB, lasA were detected in 82%, 75% and 54% of the isolates. This study reveals P. aeruginosa isolates with virulence traits and some strains showing multiple antibiotic resistance. The multiple antibiotic resistance index (MARI) of ≥ 0.2 indicates that the some isolates may have emerged from high-risk sources, thus projecting a risk to public health. However, with the high sensitivity pattern observed among the studied isolates, most of the antibiotics used in the susceptibility tests are not at peril. Hence, the use of these antibiotics is encouraged for treatment of infection attributed to P. aeruginosa. It is also pertinent to initiate strict control and rigid antibiotics therapeutic policy with surveillance programmes for multidrug-resistant pathogens to forestall the development and transmission of resistance traits in the pathogens.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Genes, Bacterial; Hospitals; Humans; Microbial Sensitivity Tests; Prevalence; Pseudomonas Infections; Pseudomonas aeruginosa; Virulence; Virulence Factors; Wastewater
PubMed: 34083705
DOI: 10.1038/s41598-021-91280-6 -
The Journal of International Medical... Oct 2019This study focused on carbapenem resistance in and examined potential ecological correlations with carbapenem use in Japan.
OBJECTIVE
This study focused on carbapenem resistance in and examined potential ecological correlations with carbapenem use in Japan.
METHODS
The proportion of carbapenem-resistant isolates from 2015 and 2016 by prefecture was obtained from the Japan Nosocomial Infections Surveillance system. Data on carbapenem use was obtained from the National Database of Health Insurance Claims. The correlation between the proportion of carbapenem-resistant isolates and carbapenem consumption was assessed in a cross-sectional manner. The study also collected information on other variables including the numbers of physicians, nurses and medical facilities per 100 000 individuals by prefecture.
RESULTS
Both the proportion of carbapenem-resistant isolates and levels of carbapenem use were higher in western Japan. Using a multivariate model, only carbapenem use remained significantly associated with the proportion of carbapenem-resistant isolates.
CONCLUSIONS
Carbapenem use and the proportion of carbapenem-resistant isolates were positively correlated. By longitudinal data collection, this approach offers an avenue to establish causal links as the frequency of carbapenem-resistant isolates starts to change in the future.
Topics: Carbapenems; Drug Resistance, Bacterial; Geography; Humans; Imipenem; Japan; Meropenem; Pseudomonas aeruginosa; Regression Analysis
PubMed: 31366256
DOI: 10.1177/0300060519864181 -
The Libyan Journal of Medicine Dec 2024is a multidrug-resistant bacterium capable of forming biofilms. This study aimed to assess resistance of clinical isolates from Libyan hospitals to antipseudomonal...
is a multidrug-resistant bacterium capable of forming biofilms. This study aimed to assess resistance of clinical isolates from Libyan hospitals to antipseudomonal antibiotics, the prevalence of selected extended-spectrum β-lactamases and carbapenemase genes among these isolates, and the microorganisms' capacity for alginate and biofilm production. Forty-five isolates were collected from four hospitals in Benghazi and Derna, Libya. Antimicrobial susceptibility was determined using agar disc diffusion. The presence of resistance genes () was screened using PCR. Biofilm formation was quantified via the crystal violet assay, while alginate production was measured spectrophotometrically. Resistance to antipseudomonal antibiotics ranged from 48.9% to 75.6%. The most prevalent resistance gene was blaNDM (26.7%), followed by blaGES-1 (17.8%). Moreover, all isolates demonstrated varying degrees of biofilm-forming ability and alginate production. No statistically significant correlation was found between biofilm formation and alginate production. The dissemination of resistant genes in P. aeruginosa, particularly carbapenemases, is of great concern. This issue is compounded by the bacteria's biofilm-forming capability. Urgent intervention and continuous surveillance are imperative to prevent further deterioration and the catastrophic spread of resistance among these formidable bacteria.
Topics: Pseudomonas aeruginosa; Libya; Humans; beta-Lactamases; Bacterial Proteins; Biofilms; Anti-Bacterial Agents; Pseudomonas Infections; Microbial Sensitivity Tests; Drug Resistance, Multiple, Bacterial; Hospitals
PubMed: 38643488
DOI: 10.1080/19932820.2024.2344320 -
FEBS Open Bio Mar 2021Combinations of human lysozyme (hLYS) and antimicrobial peptides (AMPs) are known to exhibit either additive or synergistic activity, and as a result, they have...
Combinations of human lysozyme (hLYS) and antimicrobial peptides (AMPs) are known to exhibit either additive or synergistic activity, and as a result, they have therapeutic potential for persistent and antibiotic-resistant infections. We examined hLYS activity against Pseudomonas aeruginosa when combined with six different AMPs. In contrast to prior reports, we discovered that some therapeutically relevant AMPs manifest striking antagonistic interactions with hLYS across particular concentration ranges. We further found that the synthetic AMP Tet009 can inhibit hLYS-mediated bacterial lysis. To the best of our knowledge, these results represent the first observations of antagonism between hLYS and AMPs, and they advise that future development of lytic enzyme and AMP combination therapies considers the potential for antagonistic interactions.
Topics: Antimicrobial Peptides; Bacteriolysis; Drug Antagonism; Humans; Muramidase; Pseudomonas aeruginosa
PubMed: 33480189
DOI: 10.1002/2211-5463.13094 -
Journal of Bacteriology Jan 2020Extracellular electron transfer (EET), the reduction of compounds that shuttle electrons to distal oxidants, can support bacterial survival when preferred oxidants are...
Extracellular electron transfer (EET), the reduction of compounds that shuttle electrons to distal oxidants, can support bacterial survival when preferred oxidants are not directly accessible. EET has been shown to contribute to virulence in some pathogenic organisms and is required for current generation in mediator-based fuel cells. In several species, components of the electron transport chain (ETC) have been implicated in electron shuttle reduction, raising the question of how shuttling-based metabolism is integrated with primary routes of metabolic electron flow. The clinically relevant bacterium can utilize carbon sources (i.e., electron donors) covering a broad range of reducing potentials and possesses a branched ETC that can be modulated to optimize respiratory efficiency. It also produces electron shuttles called phenazines that facilitate intracellular redox balancing, increasing the complexity of its metabolic potential. In this study, we investigated the reciprocal influence of respiratory metabolism and phenazine-associated physiology in PA14. We found that phenazine production affects respiratory activity and terminal oxidase gene expression and that carbon source identity influences the mechanisms enabling phenazine reduction. Furthermore, we found that growth in biofilms, a condition for which phenazine metabolism is critical to normal development and redox balancing, affects the composition of the phenazine pool. Together, these findings can aid interpretation of behavior during host infection and provide inroads to understanding the cross talk between primary metabolism and shuttling-based physiology in the diverse bacteria that carry out EET. The clinically relevant pathogen uses diverse organic compounds as electron donors and possesses multiple enzymes that transfer electrons from central metabolism to O These pathways support a balanced intracellular redox state and produce cellular energy. also reduces secondary metabolites called phenazines to promote redox homeostasis and virulence. In this study, we examined the reciprocal relationship between these primary and secondary routes of electron flow. We found that phenazines affect respiratory function and that the complement of phenazines produced is strongly affected by growth in assemblages called biofilms. These results provide a more nuanced understanding of redox metabolism and may inform strategies for treating persistent infections caused by this bacterium.
Topics: Biofilms; Carbon; Cystic Fibrosis; Electron Transport; Humans; Oxidation-Reduction; Phenazines; Pseudomonas aeruginosa
PubMed: 31767778
DOI: 10.1128/JB.00700-19 -
Lasers in Medical Science Sep 2020Identification and classification of microbes are vital for maintenance of normal and altered state of human health and have applications in pharmaceutical industries,...
Identification and classification of microbes are vital for maintenance of normal and altered state of human health and have applications in pharmaceutical industries, food processing, clinical analysis, and treatment. Development of methods aimed towards achieving these goals must be rapid and reliable. Conventional physiochemical and morphology-based methods of identification are often ambiguous, while newer molecular methods such as flow cytometry and polymerase chain reaction, though reliable, are time and resource intensive. Spectroscopic methods provide advantages over conventional methods as these can be fast, non-destructive, and highly specific. Surface charge of bacteria is an important parameter which can reveal composition of cell wall and is attributed to the presence of carboxyl and phosphoryl groups. Interaction of the cell with the solvent and response to various stresses can hence be measured by the changes in surface charge. In this study, we have obtained auto-fluorescence spectra (tryptophan) and dynamic light scattering (DLS) measurements from common pathogenic strains of Pseudomonas aeruginosa and Staphylococcus aureus. Fluorescence emission spectra were obtained in the range of 300-550 nm at excitation wavelength of 280 nm and DLS measurements comprised zeta potential and size parameters. Both types of measurements were performed in physiological and stress-induced conditions such as heat, sonication, and antibiotic treatment with vancomycin and cetylpyridinium chloride. Effects of these antibiotics on membrane integrity and cell viability, as obtained by DLS measurements, were statistically significant and comparable with conventional methods. Multivariate analysis enabled clustering of 83% of the samples at the genera level, based on variances from auto-fluorescence and DLS measurements.
Topics: Anti-Bacterial Agents; Biophysical Phenomena; Cetylpyridinium; Dynamic Light Scattering; Humans; Lasers; Principal Component Analysis; Pseudomonas aeruginosa; Spectrometry, Fluorescence; Staphylococcus aureus; Static Electricity; Time Factors; Vancomycin
PubMed: 31858347
DOI: 10.1007/s10103-019-02936-9 -
ACS Synthetic Biology Mar 2021Cyclic adenosine monophosphate (cAMP) is an important secondary messenger that controls carbon metabolism, type IVa pili biogenesis, and virulence in . Precise...
Cyclic adenosine monophosphate (cAMP) is an important secondary messenger that controls carbon metabolism, type IVa pili biogenesis, and virulence in . Precise manipulation of bacterial intracellular cAMP levels may enable tunable control of twitching motility or virulence, and optogenetic tools are attractive because they afford excellent spatiotemporal resolution and are easy to operate. Here, we developed an engineered strain (termed ) with light-dependent intracellular cAMP levels through introducing a photoactivated adenylate cyclase gene () into bacteria. On blue light illumination, displayed a 15-fold increase in the expression of the cAMP responsive promoter and an 8-fold increase in its twitching activity. The skin lesion area of nude mouse in a subcutaneous infection model after 2-day inoculation was increased 14-fold by blue light, making suitable for applications in controllable bacterial host infection. In addition, we achieved directional twitching motility of colonies through localized light illumination, which will facilitate the studies of contact-dependent interactions between microbial species.
Topics: Adenylyl Cyclases; Animals; Bacterial Proteins; Cyclic AMP; Disease Models, Animal; Female; Green Fluorescent Proteins; Light; Mice; Mice, Nude; Optogenetics; Promoter Regions, Genetic; Pseudomonas aeruginosa; Skin Diseases, Bacterial; Virulence
PubMed: 33667080
DOI: 10.1021/acssynbio.0c00559 -
European Journal of Clinical... Dec 2021Modifying enzyme-CrpP and its variants reduced the MICs of fluoroquinolones in Pseudomonas aeruginosa. This study investigated the dissemination and functional...
Modifying enzyme-CrpP and its variants reduced the MICs of fluoroquinolones in Pseudomonas aeruginosa. This study investigated the dissemination and functional characteristics of CrpP-like in P. aeruginosa from China. The positive rate of crpP-like genes in 228 P. aeruginosa was 25.4% (58/228), and 6 new crpP-like genes were determined. Transformation experiments showed that CrpP-like had a low effect on CIP and LEV susceptibility. The genetic of crpP-positive was diverse. Furthermore, the mean expression level of crpP was no statistical difference between fluoroquinolone-susceptible and -resistant group (P > 0.05). CrpP-like may not play a significant role in fluoroquinolone resistance in P. aeruginosa.
Topics: Anti-Bacterial Agents; Bacterial Proteins; China; Ciprofloxacin; Humans; Microbial Sensitivity Tests; Pseudomonas Infections; Pseudomonas aeruginosa
PubMed: 34097170
DOI: 10.1007/s10096-021-04287-2