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1.
Environ Monit Assess ; 194(5): 342, 2022 Apr 07.
Article in English | MEDLINE | ID: covidwho-1777746

ABSTRACT

The present study tracked the city-wide dynamics of severe acute respiratory syndrome-corona virus 2 ribonucleic acids (SARS-CoV-2 RNA) in the wastewater from nine different wastewater treatment plants (WWTPs) in Jaipur during the second wave of COVID-19 out-break in India. A total of 164 samples were collected weekly between February 19th and June 8th, 2021. SARS-CoV-2 was detected in 47.2% (52/110) influent samples and 37% (20/54) effluent samples. The increasing percentage of positive influent samples correlated with the city's increasing active clinical cases during the second wave of COVID-19 in Jaipur. Furthermore, wastewater-based epidemiology (WBE) evidence clearly showed early detection of about 20 days (9/9 samples reported positive on April 20th, 2021) before the maximum cases and maximum deaths reported in the city on May 8th, 2021. The present study further observed the presence of SARS-CoV-2 RNA in treated effluents at the time window of maximum active cases in the city even after tertiary disinfection treatments of ultraviolet (UV) and chlorine (Cl2) disinfection. The average genome concentration in the effluents and removal efficacy of six commonly used treatments, activated sludge process + chlorine disinfection (ASP + Cl2), moving bed biofilm reactor (MBBR) with ultraviolet radiations disinfection (MBBR + UV), MBBR + chlorine (Cl2), sequencing batch reactor (SBR), and SBR + Cl2, were compared with removal efficacy of SBR + Cl2 (81.2%) > MBBR + UV (68.8%) > SBR (57.1%) > ASP (50%) > MBBR + Cl2 (36.4%). The study observed the trends and prevalence of four genes (E, RdRp, N, and ORF1ab gene) based on two different kits and found that prevalence of N > ORF1ab > RdRp > E gene suggested that the effective genome concentration should be calculated based on the presence/absence of multiple genes. Hence, it is imperative to say that using a combination of different detection genes (E, N, RdRp, & ORF1ab genes) increases the sensitivity in WBE.


Subject(s)
COVID-19 , Wastewater-Based Epidemiological Monitoring , Biofilms , Bioreactors , COVID-19/epidemiology , Chlorine , Environmental Monitoring , Humans , RNA, Viral , RNA-Dependent RNA Polymerase , SARS-CoV-2 , Waste Water
2.
Int J Mol Sci ; 23(6)2022 Mar 18.
Article in English | MEDLINE | ID: covidwho-1760652

ABSTRACT

The presence of co-infections or superinfections with bacterial pathogens in COVID-19 patients is associated with poor outcomes, including increased morbidity and mortality. We hypothesized that SARS-CoV-2 and its components interact with the biofilms generated by commensal bacteria, which may contribute to co-infections. This study employed crystal violet staining and particle-tracking microrheology to characterize the formation of biofilms by Streptococcus pneumoniae and Staphylococcus aureus that commonly cause secondary bacterial pneumonia. Microrheology analyses suggested that these biofilms were inhomogeneous soft solids, consistent with their dynamic characteristics. Biofilm formation by both bacteria was significantly inhibited by co-incubation with recombinant SARS-CoV-2 spike S1 subunit and both S1 + S2 subunits, but not with S2 extracellular domain nor nucleocapsid protein. Addition of spike S1 and S2 antibodies to spike protein could partially restore bacterial biofilm production. Furthermore, biofilm formation in vitro was also compromised by live murine hepatitis virus, a related beta-coronavirus. Supporting data from LC-MS-based proteomics of spike-biofilm interactions revealed differential expression of proteins involved in quorum sensing and biofilm maturation, such as the AI-2E family transporter and LuxS, a key enzyme for AI-2 biosynthesis. Our findings suggest that these opportunistic pathogens may egress from biofilms to resume a more virulent planktonic lifestyle during coronavirus infections. The dispersion of pathogens from biofilms may culminate in potentially severe secondary infections with poor prognosis. Further detailed investigations are warranted to establish bacterial biofilms as risk factors for secondary pneumonia in COVID-19 patients.


Subject(s)
Antibiosis , Biofilms , Coronavirus/physiology , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Staphylococcus aureus/physiology , Streptococcus pneumoniae/physiology , Animals , Coinfection , Gene Expression Regulation, Bacterial , Humans , Mice , Microbial Interactions , Serogroup , Staphylococcus aureus/classification , Streptococcus pneumoniae/classification
3.
Molecules ; 27(4)2022 Feb 13.
Article in English | MEDLINE | ID: covidwho-1686904

ABSTRACT

(1) Background: Acne is a widespread skin disease, especially among adolescents. Following the COVID-19 pandemic and the use of masks, the problem has been affecting a greater number of people, and the attention of the skin care beauty routine cosmetics has been focused on the "Maskne", caused by the sebum excretion rate (SER) that stimulates microbial proliferation. (2) Methods: the present study was focused on the rheological characterization and quality assurance of the preservative system of an anti-acne serum. The biological effectiveness (cytotoxicity-skin and eye irritation-antimicrobial, biofilm eradication and anti-inflammatory activity) was evaluated in a monolayer cell line of keratinocytes (HaCaT) and on 3D models (reconstructed human epidermis, RHE and human reconstructed corneal epithelium, HCE). The Cutibacterium acnes, as the most relevant acne-inducing bacterium, is chosen as a pro-inflammatory stimulus and to evaluate the antimicrobial activity of the serum. (3) Results and Conclusions: Rheology allows to simulate serum behavior at rest, extrusion and application, so the serum could be defined as having a solid-like behavior and being pseudoplastic. The preservative system is in compliance with the criteria of the reference standard. Biological effectiveness evaluation shows non-cytotoxic and irritant behavior with a good antimicrobial and anti-inflammatory activity of the formulation, supporting the effectiveness of the serum for acne-prone skin treatment.


Subject(s)
Acne Vulgaris/drug therapy , Anti-Bacterial Agents , Biofilms/drug effects , COVID-19 , Cosmeceuticals , Pandemics , Propionibacteriaceae/physiology , SARS-CoV-2 , Acne Vulgaris/microbiology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Cell Line, Transformed , Cosmeceuticals/chemistry , Cosmeceuticals/pharmacology , Humans
4.
Science ; 372(6547): 1169-1175, 2021 06 11.
Article in English | MEDLINE | ID: covidwho-1583231

ABSTRACT

Emergent resistance to all clinical antibiotics calls for the next generation of therapeutics. Here we report an effective antimicrobial strategy targeting the bacterial hydrogen sulfide (H2S)-mediated defense system. We identified cystathionine γ-lyase (CSE) as the primary generator of H2S in two major human pathogens, Staphylococcus aureus and Pseudomonas aeruginosa, and discovered small molecules that inhibit bacterial CSE. These inhibitors potentiate bactericidal antibiotics against both pathogens in vitro and in mouse models of infection. CSE inhibitors also suppress bacterial tolerance, disrupting biofilm formation and substantially reducing the number of persister bacteria that survive antibiotic treatment. Our results establish bacterial H2S as a multifunctional defense factor and CSE as a drug target for versatile antibiotic enhancers.


Subject(s)
Anti-Bacterial Agents/pharmacology , Cystathionine gamma-Lyase/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Hydrogen Sulfide/metabolism , Pseudomonas aeruginosa/drug effects , Staphylococcus aureus/drug effects , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Biofilms , Crystallography, X-Ray , Cystathionine gamma-Lyase/chemistry , Cystathionine gamma-Lyase/genetics , Cystathionine gamma-Lyase/metabolism , Drug Discovery , Drug Resistance, Bacterial , Drug Synergism , Drug Tolerance , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/metabolism , Mice , Microbial Sensitivity Tests , Models, Molecular , Molecular Docking Simulation , Molecular Structure , Pseudomonas Infections/drug therapy , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/enzymology , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/growth & development , Small Molecule Libraries/chemistry , Small Molecule Libraries/metabolism , Small Molecule Libraries/pharmacology , Staphylococcal Infections/drug therapy , Staphylococcal Infections/microbiology , Staphylococcus aureus/enzymology , Staphylococcus aureus/genetics , Staphylococcus aureus/growth & development
5.
Med Hypotheses ; 159: 110760, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1586982

ABSTRACT

Ventilator-associated pneumonia (VAP) has been claiming many lives in the intensive care unit (ICU) during COVID-19. Oral biofilm and bacterial contamination that can be passed on from the oral cavity to the lungs during endotracheal intubation has been found to be the main culprit. Bioluminescence-based assays are emerging as potential clinical diagnostics methods. Hence, we hypothesize that the bioluminescent imaging technique can be used in the ICU to determine the load of biofilm-associated with patients undergoing endotracheal intubation. Early detection of such infections and their management can effectively bring down mortality and influence the death rate in ICU caused due to VAP. Government agencies and policymakers should be made to take this issue of deaths in the ICU due to VAP more seriously and act judiciously to methods such as bioluminescence based on sound scientific evidence.


Subject(s)
COVID-19 , Pneumonia, Ventilator-Associated , Biofilms , Humans , Intensive Care Units , Respiration, Artificial , SARS-CoV-2
6.
Biomed Res Int ; 2021: 2347872, 2021.
Article in English | MEDLINE | ID: covidwho-1582891

ABSTRACT

Introduction: Patients with acute respiratory distress syndrome caused by coronavirus disease 2019 (COVID-19) are at risk for superadded infections, especially infections caused by multidrug resistant (MDR) pathogens. Before the COVID-19 pandemic, the prevalence of MDR infections, including infections caused by MDR Klebsiella pneumoniae (K. pneumoniae), was very high in Iran. This study is aimed at assessing the genetic diversity, antimicrobial resistance pattern, and biofilm formation in K. pneumoniae isolates obtained from patients with COVID-19 and ventilator-associated pneumonia (VAP) hospitalized in an intensive care unit (ICU) in Iran. Methods: In this cross-sectional study, seventy K. pneumoniae isolates were obtained from seventy patients with COVID-19 hospitalized in the ICU of Shahid Beheshti hospital, Kashan, Iran, from May to September, 2020. K. pneumoniae was detected through the ureD gene. Antimicrobial susceptibility testing was done using the Kirby-Bauer disc diffusion method, and biofilm was detected using the microtiter plate assay method. Genetic diversity was also analyzed through polymerase chain reaction based on enterobacterial repetitive intergenic consensus (ERIC-PCR). The BioNumerics software (v. 8.0, Applied Maths, Belgium) was used for analyzing the data and drawing dendrogram and minimum spanning tree. Findings. K. pneumoniae isolates had varying levels of resistance to antibiotics meropenem (80.4%), cefepime-aztreonam-piperacillin/tazobactam (70%), tobramycin (61.4%), ciprofloxacin (57.7%), gentamicin (55.7%), and imipenem (50%). Around 77.14% of isolates were MDR, and 42.8% of them formed biofilm. Genetic diversity analysis revealed 28 genotypes (E1-E28) and 74.28% of isolates were grouped into ten clusters (i.e., clusters A-J). Clusters were further categorized into three major clusters, i.e., clusters E, H, and J. Antimicrobial resistance to meropenem, tobramycin, gentamicin, and ciprofloxacin in cluster J was significantly higher than cluster H, denoting significant relationship between ERIC clusters and antimicrobial resistance. However, there was no significant difference among major clusters E, H, and J respecting biofilm formation. Conclusion: K. pneumoniae isolates obtained from patients with COVID-19 have high antimicrobial resistance, and 44.2% of them have genetic similarity and can be clustered in three major clusters. There is a significant difference among clusters respecting antimicrobial resistance.


Subject(s)
Biofilms/growth & development , COVID-19/microbiology , Drug Resistance, Multiple, Bacterial/genetics , Genetic Variation/genetics , Klebsiella Infections/microbiology , Klebsiella pneumoniae/genetics , Pneumonia, Ventilator-Associated/microbiology , Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , COVID-19/virology , Cross-Sectional Studies , Humans , Intensive Care Units , Iran , Klebsiella Infections/drug therapy , Klebsiella pneumoniae/drug effects , Microbial Sensitivity Tests/methods , Pandemics/prevention & control , Pneumonia, Ventilator-Associated/virology
7.
Int J Mol Sci ; 22(24)2021 Dec 14.
Article in English | MEDLINE | ID: covidwho-1572494

ABSTRACT

Low density polyethylene (LDPE) films covered with active coatings containing mixtures of rosemary, raspberry, and pomegranate CO2 extracts were found to be active against selected bacterial strains that may extend the shelf life of food products. The coatings also offer antiviral activity, due to their influence on the activity of Φ6 bacteriophage, selected as a surrogate for SARS-CoV-2 particles. The mixture of these extracts could be incorporated into a polymer matrix to obtain a foil with antibacterial and antiviral properties. The initial goal of this work was to obtain active LDPE films containing a mixture of CO2 extracts of the aforementioned plants, incorporated into an LDPE matrix via an extrusion process. The second aim of this study was to demonstrate the antibacterial properties of the active films against Gram-positive and Gram-negative bacteria, and to determine the antiviral effect of the modified material on Φ6 bacteriophage. In addition, an analysis was made on the influence of the active mixture on the polymer physicochemical features, e.g., mechanical and thermal properties, as well as its color and transparency. The results of this research indicated that the LDPE film containing a mixture of raspberry, rosemary, and pomegranate CO2 extracts incorporated into an LDPE matrix inhibited the growth of Staphylococcus aureus. This film was also found to be active against Bacillus subtilis. This modified film did not inhibit the growth of Escherichia coli and Pseudomonas syringae cells; however, their number decreased significantly. The LDPE active film was also found to be active against Φ6 particles, meaning that the film had antiviral properties. The incorporation of the mixture of CO2 extracts into the polymer matrix affected its mechanical properties. It was observed that parameters describing mechanical properties decreased, although did not affect the transition of LDPE significantly. Additionally, the modified film exhibited barrier properties towards UV radiation. Modified PE/CO2 extracts films could be applied as a functional food packaging material with antibacterial and antiviral properties.


Subject(s)
Food Packaging/methods , Plant Extracts/pharmacology , Polyethylene/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Bacteriophage phi 6/drug effects , Biofilms , Chitosan/chemistry , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Humans , Plant Extracts/chemistry , Polyethylene/pharmacology , Polymers/chemistry , Pomegranate , Rosmarinus/chemistry , Rubus , SARS-CoV-2/drug effects
8.
Bioorg Chem ; 119: 105550, 2022 02.
Article in English | MEDLINE | ID: covidwho-1561636

ABSTRACT

Infectious diseases caused by new or unknown bacteria and viruses, such as anthrax, cholera, tuberculosis and even COVID-19, are a major threat to humanity. Thus, the development of new synthetic compounds with efficient antimicrobial activity is a necessity. Herein, rationally designed novel multifunctional cationic alternating copolymers were directly synthesized through a step-growth polymerization reaction using a bivalent electrophilic cross-linker containing disulfide bonds and a diamine heterocyclic ring. To optimize the activity of these alternating copolymers, several different diamines and cross-linkers were explored to find the highest antibacterial effects. The synthesized nanopolymers not only displayed good to excellent antibacterial activity as judged by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, and Escherichia coli, but also reduced the number of biofilm cells even at low concentrations, without killing mammalian cells. Furthermore, in vivo experiments using infected burn wounds in mice demonstrated good antibacterial activity and stimulated wound healing, without causing systemic inflammation. These findings suggest that the multifunctional cationic nanopolymers have potential as a novel antibacterial agent for eradication of multidrug resistant bacterial infections.


Subject(s)
Anti-Bacterial Agents/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Biofilms/drug effects , Cations/pharmacology , Polymers/pharmacology , Wound Healing/drug effects , Amines/chemistry , Animals , Bacteria/drug effects , Bacterial Infections/drug therapy , Bacterial Infections/etiology , Burns/complications , COVID-19 , Cell Survival/drug effects , Cross-Linking Reagents , Drug Resistance, Multiple, Bacterial/drug effects , HEK293 Cells/drug effects , Humans , Mice , Microbial Sensitivity Tests , Polymers/chemistry
9.
Int J Mol Sci ; 22(22)2021 Nov 20.
Article in English | MEDLINE | ID: covidwho-1534089

ABSTRACT

Carbapenem-resistant A. baumannii (CRAB) infection can cause acute host reactions that lead to high-fatality sepsis, making it important to develop new therapeutic options. Previously, we developed a short 9-meric peptide, Pro9-3D, with significant antibacterial and cytotoxic effects. In this study, we attempted to produce safer peptide antibiotics against CRAB by reversing the parent sequence to generate R-Pro9-3 and R-Pro9-3D. Among the tested peptides, R-Pro9-3D had the most rapid and effective antibacterial activity against Gram-negative bacteria, particularly clinical CRAB isolates. Analyses of antimicrobial mechanisms based on lipopolysaccharide (LPS)-neutralization, LPS binding, and membrane depolarization, as well as SEM ultrastructural investigations, revealed that R-Pro9-3D binds strongly to LPS and impairs the membrane integrity of CRAB by effectively permeabilizing its outer membrane. R-Pro9-3D was also less cytotoxic and had better proteolytic stability than Pro9-3D and killed biofilm forming CRAB. As an LPS-neutralizing peptide, R-Pro9-3D effectively reduced LPS-induced pro-inflammatory cytokine levels in RAW 264.7 cells. The antiseptic abilities of R-Pro9-3D were also investigated using a mouse model of CRAB-induced sepsis, which revealed that R-Pro9-3D reduced multiple organ damage and attenuated systemic infection by acting as an antibacterial and immunosuppressive agent. Thus, R-Pro9-3D displays potential as a novel antiseptic peptide for treating Gram-negative CRAB infections.


Subject(s)
Acinetobacter Infections/drug therapy , Acinetobacter baumannii/drug effects , Drug Resistance, Bacterial/genetics , Peptides/pharmacology , Acinetobacter Infections/genetics , Acinetobacter Infections/microbiology , Acinetobacter baumannii/pathogenicity , Anti-Infective Agents, Local/pharmacology , Biofilms/drug effects , Carbapenems/adverse effects , Carbapenems/pharmacology , Humans , Microbial Sensitivity Tests
10.
Sci Total Environ ; 813: 151919, 2022 Mar 20.
Article in English | MEDLINE | ID: covidwho-1531803

ABSTRACT

Recent outbreaks caused by coronaviruses and their supposed potential fecal-oral transmission highlight the need for understanding the survival of infectious coronavirus in domestic sewers. To date, the survivability and decay of coronaviruses were predominately studied using small volumes of wastewater (normally 5-30 mL) in vials (in-vial tests). However, real sewers are more complicated than bulk wastewater (wastewater matrix only), in particular the presence of sewer biofilms and different operational conditions. This study investigated the decay of infectious human coronavirus 229E (HCoV-229E) and feline infectious peritonitis virus (FIPV), two typical surrogate coronaviruses, in laboratory-scale reactors mimicking the gravity (GS, gravity-driven sewers) and rising main sewers (RM, pressurized sewers) with and without sewer biofilms. The in-sewer decay of both coronaviruses was greatly enhanced in comparison to those reported in bulk wastewater through in-vial tests. 99% of HCoV-229E and FIPV decayed within 2 h under either GS or RM conditions with biofilms, in contrast to 6-10 h without biofilms. There is limited difference in the decay of HCoV and FIPV in reactors operated as RM or GS, with the T90 and T99 difference of 7-10 min and 14-20 min, respectively. The decay of both coronaviruses in sewer biofilm reactors can be simulated by biphasic first-order kinetic models, with the first-order rate constant 2-4 times higher during the first phase than the second phase. The decay of infectious HCoV and FIPV was significantly faster in the reactors with sewer biofilms than in the reactors without biofilms, suggesting an enhanced decay of these surrogate viruses due to the presence of biofilms and related processes. The mechanism of biofilms in virus adsorption and potential inactivation remains unclear and requires future investigations. The results indicate that the survivability of infectious coronaviruses detected using bulk wastewater overestimated the infectivity risk of coronavirus during wastewater transportations in sewers or the downstream treatment.


Subject(s)
Coronavirus , Waste Water , Biofilms , Humans , Kinetics , Sewage
11.
Sci Rep ; 11(1): 22543, 2021 11 19.
Article in English | MEDLINE | ID: covidwho-1526103

ABSTRACT

Microbial contamination is one of the major dreadful problems that raises hospitalization, morbidity and mortality rates globally, which subsequently obstructs socio-economic progress. The continuous misuse and overutilization of antibiotics participate mainly in the emergence of microbial resistance. To circumvent such a multidrug-resistance phenomenon, well-defined nanocomposite structures have recently been employed. In the current study, a facile, novel and cost-effective approach was applied to synthesize Ag@Ag2O core-shell nanocomposites (NCs) via chemical method. Several techniques were used to determine the structural, morphological, and optical characteristics of the as-prepared NCs. XRD, Raman, FTIR, XPS and SAED analysis revealed a crystalline hybrid structure of Ag core and Ag2O shell. Besides, SEM and HRTEM micrographs depicted spherical nanoparticles with size range of 19-60 nm. Additionally, zeta potential and fluorescence spectra illustrated aggregated nature of Ag@Ag2O NCs by - 5.34 mV with fluorescence emission peak at 498 nm. Ag@Ag2O NCs exhibited higher antimicrobial, antibiofilm, and algicidal activity in dose-dependent behavior. Interestingly, a remarkable mycocidal potency by 50 µg of Ag@Ag2O NCs against Candida albican; implying promising activity against COVID-19 white fungal post-infections. Through assessing cytotoxicity, Ag@Ag2O NCs exhibited higher safety against Vero cells than bulk silver nitrate by more than 100-fold.


Subject(s)
Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Biofilms/drug effects , Nanocomposites/chemistry , Oxides/chemistry , Silver Compounds/chemistry , Animals , Anti-Infective Agents/chemical synthesis , Candida albicans/drug effects , Cell Survival/drug effects , Chlorella vulgaris/drug effects , Chlorocebus aethiops , Disinfectants/chemical synthesis , Disinfectants/chemistry , Disinfectants/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Metal Nanoparticles/chemistry , Oxides/chemical synthesis , Pseudomonas aeruginosa/drug effects , Silver Compounds/chemical synthesis , Silver Nitrate/pharmacology , Staphylococcus aureus/drug effects , Vero Cells
12.
Biomaterials ; 280: 121249, 2022 01.
Article in English | MEDLINE | ID: covidwho-1507702

ABSTRACT

The emergence and spread of antibiotic resistance is one of the biggest challenges in public health. There is an urgent need to discover novel agents against the occurrence of multidrug-resistant bacteria, such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. The drug-resistant pathogens are able to grow and persist in infected sites, including biofilms, phagosomes, or phagolysosomes, which are more difficult to eradicate than planktonic ones and also foster the development of drug resistance. For years, various nano-antibacterial agents have been developed in the forms of antibiotic nanocarriers. Inorganic nanoparticles with intrinsic antibacterial activity and inert nanoparticles assisted by external stimuli, including heat, photon, magnetism, or sound, have also been discovered. Many of these strategies are designed to target the unique microenvironment of bacterial infections, which have shown potent antibacterial effects in vitro and in vivo. This review summarizes ongoing efforts on antibacterial nanotherapeutic strategies related to bacterial infection microenvironments, including targeted antibacterial therapy and responsive antibiotic delivery systems. Several grand challenges and future directions for the development and translation of effective nano-antibacterial agents are also discussed. The development of innovative nano-antibacterial agents could provide powerful weapons against drug-resistant bacteria in systemic or local bacterial infections in the foreseeable future.


Subject(s)
Bacterial Infections , Methicillin-Resistant Staphylococcus aureus , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Biofilms , Drug Resistance, Multiple, Bacterial , Humans , Microbial Sensitivity Tests
13.
Sensors (Basel) ; 21(21)2021 Oct 30.
Article in English | MEDLINE | ID: covidwho-1512564

ABSTRACT

Contamination inspection is an ongoing concern for food distributors, restaurant owners, caterers, and others who handle food. Food contamination must be prevented, and zero tolerance legal requirements and damage to the reputation of institutions or restaurants can be very costly. This paper introduces a new handheld fluorescence-based imaging system that can rapidly detect, disinfect, and document invisible organic residues and biofilms which may host pathogens. The contamination, sanitization inspection, and disinfection (CSI-D) system uses light at two fluorescence excitation wavelengths, ultraviolet C (UVC) at 275 nm and violet at 405 nm, for the detection of organic residues, including saliva and respiratory droplets. The 275 nm light is also utilized to disinfect pathogens commonly found within the contaminated residues. Efficacy testing of the neutralizing effects of the ultraviolet light was conducted for Aspergillus fumigatus, Streptococcus pneumoniae, and the influenza A virus (a fungus, a bacterium, and a virus, respectively, each commonly found in saliva and respiratory droplets). After the exposure to UVC light from the CSI-D, all three pathogens experienced deactivation (> 99.99%) in under ten seconds. Up to five-log reductions have also been shown within 10 s of UVC irradiation from the CSI-D system.


Subject(s)
Disinfection , Ultraviolet Rays , Biofilms , Fungi , Optical Imaging
14.
Photochem Photobiol Sci ; 20(11): 1497-1545, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1491552

ABSTRACT

Photodynamic therapy is witnessing a revival of its origins as a response to the rise of multi-drug resistant infections and the shortage of new classes of antibiotics. Photodynamic disinfection (PDDI) of microorganisms is making progresses in preclinical models and in clinical cases, and the perception of its role in the clinical armamentarium for the management of infectious diseases is changing. We review the positioning of PDDI from the perspective of its ability to respond to clinical needs. Emphasis is placed on the pipeline of photosensitizers that proved effective to inactivate biofilms, showed efficacy in animal models of infectious diseases or reached clinical trials. Novel opportunities resulting from the COVID-19 pandemic are briefly discussed. The molecular features of promising photosensitizers are emphasized and contrasted with those of photosensitizers used in the treatment of solid tumors. The development of photosensitizers has been accompanied by the fabrication of a variety of affordable and customizable light sources. We critically discuss the combination between photosensitizer and light source properties that may leverage PDDI and expand its applications to wider markets. The success of PDDI in the management of infectious diseases will ultimately depend on the efficacy of photosensitizers, affordability of the light sources, simplicity of the procedures, and availability of fast and efficient treatments.


Subject(s)
Communicable Disease Control/methods , Drug Resistance, Microbial/drug effects , Drug Resistance, Multiple/drug effects , Photochemotherapy , Photosensitizing Agents/therapeutic use , Animals , Bacteria/drug effects , Biofilms/drug effects , Fungi/drug effects , Humans , Microbial Sensitivity Tests , Neoplasms/drug therapy , Photosensitizing Agents/pharmacology
15.
J Am Chem Soc ; 143(43): 17891-17909, 2021 11 03.
Article in English | MEDLINE | ID: covidwho-1483091

ABSTRACT

The emergence of multi-drug-resistant pathogens threatens the healthcare systems world-wide. Recent advances in phototherapy (PT) approaches mediated by photo-antimicrobials (PAMs) provide new opportunities for the current serious antibiotic resistance. During the PT treatment, reactive oxygen species or heat produced by PAMs would react with the cell membrane, consequently leaking cytoplasm components and effectively eradicating different pathogens like bacteria, fungi, viruses, and even parasites. This Perspective will concentrate on the development of different organic photo-antimicrobials (OPAMs) and their application as practical therapeutic agents into therapy for local infections, wound dressings, and removal of biofilms from medical devices. We also discuss how to design highly efficient OPAMs by modifying the chemical structure or conjugating with a targeting component. Moreover, this Perspective provides a discussion of the general challenges and direction for OPAMs and what further needs to be done. It is hoped that through this overview, OPAMs can prosper and will be more widely used for microbial infections in the future, especially at a time when the global COVID-19 epidemic is getting more serious.


Subject(s)
Anti-Infective Agents/chemistry , Drug Design , Phototherapy/methods , Animals , Anti-Infective Agents/pharmacology , Anti-Infective Agents/therapeutic use , Bacteria/drug effects , Biofilms/drug effects , Biofilms/radiation effects , Coloring Agents/chemistry , Coloring Agents/pharmacology , Equipment and Supplies/microbiology , Equipment and Supplies/virology , Escherichia coli/drug effects , Escherichia coli/physiology , Eye Diseases/drug therapy , Eye Diseases/pathology , Fungi/drug effects , Graphite/chemistry , Light , Nanoparticles/chemistry , Nanoparticles/toxicity , Photosensitizing Agents/chemistry , Photosensitizing Agents/pharmacology , Photosensitizing Agents/therapeutic use , Quantum Theory , Reactive Oxygen Species/metabolism , Viruses/drug effects
16.
Biomolecules ; 11(10)2021 10 09.
Article in English | MEDLINE | ID: covidwho-1480576

ABSTRACT

The continual plastic accumulation in the environment and the hazardous consequences determine the interest in thermophiles as possible effective plastic degraders, due to their unique metabolic mechanisms and change of plastic properties at elevated temperatures. PCL is one of major biodegradable plastics with promising application to replace existing non-biodegradable polymers. Metagenomic analysis of the phylogenetic diversity in plastic contaminated area of Marikostinovo hot spring, Bulgaria revealed a higher number taxonomic groups (11) in the sample enriched without plastic (Marikostinovo community, control sample, MKC-C) than in that enriched in the presence of poly-ε-caprolactone (PCL) (MKC-P), (7). A strong domination of the phylum Proteobacteria was observed for MKC-C, while the dominant phyla in MKC-P were Deinococcus-Thermus and Firmicutes. Among the strains isolated from MKC-P, the highest esterase activity was registered for Brevibacillus thermoruber strain 7 at 55 °C. Its co-cultivation with another isolate resulted in ~10% increase in enzyme activity. During a 28-day biodegradation process, a decrease in PCL molecular weight and weight loss were established resulting in 100% degradation by MKC-P and 63.6% by strain 7. PCL degradation intermediate profiles for MKC-P and pure strain were similar. Broken plastic pieces from PCL surface and formation of a biofilm by MKC-P were observed by SEM, while the pure strain caused significant deformation of PCL probes without biofilm formation.


Subject(s)
Brevibacillus/isolation & purification , Brevibacillus/metabolism , Hot Springs/microbiology , Polyesters/metabolism , Temperature , Biodegradation, Environmental , Biofilms/growth & development , Bulgaria , Chromatography, Gel , Esterases/metabolism , Phylogeny , Plastics
17.
Plant Biotechnol J ; 19(10): 2113-2125, 2021 10.
Article in English | MEDLINE | ID: covidwho-1447958

ABSTRACT

Current approaches for oral health care rely on procedures that are unaffordable to impoverished populations, whereas aerosolized droplets in the dental clinic and poor oral hygiene may contribute to spread of several infectious diseases including COVID-19, requiring new solutions for dental biofilm/plaque treatment at home. Plant cells have been used to produce monoclonal antibodies or antimicrobial peptides for topical applications to decrease colonization of pathogenic microbes on dental surface. Therefore, we investigated an affordable method for dental biofilm disruption by expressing lipase, dextranase or mutanase in plant cells via the chloroplast genome. Antibiotic resistance gene used to engineer foreign genes into the chloroplast genome were subsequently removed using direct repeats flanking the aadA gene and enzymes were successfully expressed in marker-free lettuce transplastomic lines. Equivalent enzyme units of plant-derived lipase performed better than purified commercial enzymes against biofilms, specifically targeting fungal hyphae formation. Combination of lipase with dextranase and mutanase suppressed biofilm development by degrading the biofilm matrix, with concomitant reduction of bacterial and fungal accumulation. In chewing gum tablets formulated with freeze-dried plant cells, expressed protein was stable up to 3 years at ambient temperature and was efficiently released in a time-dependent manner using a mechanical chewing simulator device. Development of edible plant cells expressing enzymes eliminates the need for purification and cold-chain transportation, providing a potential translatable therapeutic approach. Biofilm disruption through plant enzymes and chewing gum-based delivery offers an effective and affordable dental biofilm control at home particularly for populations with minimal oral care access.


Subject(s)
COVID-19 , Chewing Gum , Biofilms , Chloroplasts , Delivery of Health Care , Humans , SARS-CoV-2
18.
Molecules ; 26(18)2021 Sep 11.
Article in English | MEDLINE | ID: covidwho-1410347

ABSTRACT

Current studies suggest that cariogenic bacteria in dental plaque influence the severity of COVID-19 complications since the oral cavity is a reservoir for respiratory pathogens potentially responsible for the development of hospital-acquired pneumonia. This article focuses on the association between dental plaque and COVID-19 concerning the influence of altered oral biofilm on the risk of increased severity of SARS-CoV-2 infection. Moreover, it concentrates on the usefulness of propolis, with its apitherapeutic antibacterial properties, for treating oral bacterial infections co-occurring with SARS-CoV-2 infection. A review of the literature on PubMed, Cochrane Library and Medline between 2000 and 2021 revealed 56 published articles indicating that a link between dental plaque and COVID-19 complications was probable. Furthermore, they indicated that propolis may minimize COVID-19 severity by reducing dental plaque accumulation. The possibility that improved oral health could reduce the risk of COVID-19 complications should be of interest to scientists.


Subject(s)
Biofilms , COVID-19 , Dental Caries , Dental Plaque , Mouth Diseases , Propolis/therapeutic use , Animals , Anti-Infective Agents/therapeutic use , Biofilms/drug effects , COVID-19/drug therapy , COVID-19/microbiology , Dental Caries/drug therapy , Dental Caries/microbiology , Dental Plaque/drug therapy , Dental Plaque/microbiology , Humans , Mouth Diseases/drug therapy , Mouth Diseases/microbiology , Oral Health
19.
Molecules ; 26(17)2021 Aug 27.
Article in English | MEDLINE | ID: covidwho-1403854

ABSTRACT

This paper presents the results of the first part of testing a novel electrospun fiber mat based on a unique macromolecule: polyisobutylene (PIB). A PIB-based compound containing zinc oxide (ZnO) was electrospun into self-supporting mats of 203.75 and 295.5 g/m2 that were investigated using a variety of techniques. The results show that the hydrophobic mats are not cytotoxic, resist fibroblast cell adhesion and biofilm formation and are comfortable and easy to breathe through for use as a mask. The mats show great promise for personal protective equipment and other applications.


Subject(s)
Polyenes/chemistry , Polymers/chemistry , Biofilms/drug effects , Cell Adhesion/drug effects , Cells, Cultured , Fibroblasts/drug effects , Humans , Materials Testing/methods , Nanofibers/chemistry , Zinc Oxide/chemistry
20.
Appl Biochem Biotechnol ; 194(2): 671-693, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1375835

ABSTRACT

The growth of respiratory diseases, as witnessed through the SARS and COVID-19 outbreaks, and antimicrobial-resistance together pose a serious threat to humanity. One reason for antimicrobial resistance is formation of bacterial biofilms. In this study the sulphated polysaccharides from green algae Chlamydomonas reinhardtii (Cr-SPs) is tested for its antibacterial and antibiofilm potential against Klebsiella pneumoniae and Serratia marcescens. Agar cup assay clearly indicated the antibacterial potential of Cr-SPs. Minimum inhibitory concentration (MIC50) of Cr-SPs against Klebsiella pneumoniae was found to be 850 µg/ml, and it is 800 µg/ml in Serratia marcescens. Time-kill and colony-forming ability assays suggest the concentration-dependent bactericidal potential of Cr-SPs. Cr-SPs showed 74-100% decrease in biofilm formation in a concentration-dependent manner by modifying the cell surface hydrophobic properties of these bacteria. Cr-SPs have also distorted preformed-biofilms by their ability to interact and destroy the extra polymeric substance and eDNA of the matured biofilm. Scanning electron microscopy analysis showed that Cr-SPs effectively altered the morphology of these bacterial cells and distorted the bacterial biofilms. Furthermore reduced protease, urease and prodigiosin pigment production suggest that Cr-SPs interferes the quorum sensing mechanism in these bacteria. The current study paves way towards developing Cr-SPs as a control strategy for treatment of respiratory tract infections.


Subject(s)
Biofilms/drug effects , Polysaccharides/pharmacology , Quorum Sensing/drug effects , Respiratory Tract Infections/drug therapy , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Biofilms/growth & development , COVID-19/drug therapy , COVID-19/virology , Chlorophyta/chemistry , Humans , Klebsiella pneumoniae/growth & development , Klebsiella pneumoniae/pathogenicity , Microbial Sensitivity Tests , Polysaccharides/chemistry , Respiratory Tract Infections/microbiology , SARS-CoV-2/drug effects , Serratia marcescens/growth & development , Serratia marcescens/pathogenicity
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