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American Journal of Infection Control Jun 2024The mounted UV-C lamp requires no separate space or labor for transport, but data on its effectiveness for surface disinfection are scarce. We aimed to evaluate the...
BACKGROUND
The mounted UV-C lamp requires no separate space or labor for transport, but data on its effectiveness for surface disinfection are scarce. We aimed to evaluate the performance of ceiling-mounted UV-C lamps.
METHODS
This study was conducted in an empty room with UV-C lamps in the biocontainment unit of a tertiary care hospital in South Korea. UV-C lamps were installed on the ceiling of the patient room, anteroom, and toilet. Each pathogen (Staphylococcus aureus, Escherichia coli, Candida krusei, Bacillus cereus, and Mycobacterium peregrinum) was inoculated on blood agar plates and placed in 20 selected places from the UV-C lamp, and irradiation was applied for 15 min. As a control group, the bacterial solution was diluted 10,000 times and UV was not applied.
RESULTS
A mean ± SD of 5.95 ± 0.91 log reduction was observed with UV irradiation compared with the control. The log reduction was greatest for S. aureus [median, 7.05 (IQR, 6.49-7.26)] and least for M. peregrinum [median, 4.88 (IQR, 4.58-5.24)]. The degree of log reduction was inversely proportional to the square of the distance from the UV-C lamp (R = -0.12, p < 0.001).
CONCLUSIONS
In this study, ceiling-mounted UV-C demonstrated effective disinfection of at least 4-log reduction of the test organisms within a 4-m distance. Mounted UV-C lighting is a considerable option for improving surface disinfection.
PubMed: 38945300
DOI: 10.1016/j.ajic.2024.06.020 -
Biochemical Pharmacology Jun 2024Methicillin-resistant Staphylococcus aureus (MRSA), a notorious bacterium with high drug resistance and easy recurrence after surgery, has posed significant clinical...
Methicillin-resistant Staphylococcus aureus (MRSA), a notorious bacterium with high drug resistance and easy recurrence after surgery, has posed significant clinical treatment challenges. In the current scarcity of new antibiotics, the identification of adjuvants to existing antibiotics is a promising approach to combat infections caused by multidrug-resistant Gram-positive bacteria. The in vitro synergy test, which included a MIC assay, time-kill curve, antimicrobial susceptibility testing, and live/dead bacteria staining assay, revealed that laurocapram, a widely used chemical transdermal enhancer, could potentiate the antibacterial activity of cephalosporins against MRSA. In vitro, laurocapram combined with cefixime showed an excellent synergistic activity against MRSA (FICI = 0.28 ± 0.00). In addition, the combination of laurocapram and cefixime may inhibited the formation of MRSA biofilm and caused cell membrane damage. Following that, we discovered that combining laurocapram with cefixime could alleviate the symptoms of mice in the MRSA skin infection model and the MRSA pneumonia model. In conclusion, laurocapram is a promising and low-cost antibacterial adjuvant, providing a new strategy for further exploring the use of lower doses of cephalosporins to combat MRSA infection.
PubMed: 38945279
DOI: 10.1016/j.bcp.2024.116404 -
European Journal of Medicinal Chemistry Jun 2024The global microbial resistance is a serious threat to human health, and multitargeting compounds are considered to be promising to combat microbial resistance. In this...
Synthesis and antibacterial medicinal evaluation of carbothioamido hydrazonyl thiazolylquinolone with multitargeting antimicrobial potential to combat increasingly global resistance.
The global microbial resistance is a serious threat to human health, and multitargeting compounds are considered to be promising to combat microbial resistance. In this work, a series of new thiazolylquinolones with multitargeting antimicrobial potential were developed through multi-step reactions using triethoxymethane and substituted anilines as start materials. Their structures were confirmed by H NMR, C NMR and HRMS spectra. Antimicrobial evaluation revealed that some of the target compounds could effectively inhibit microbial growth. Especially, carbothioamido hydrazonyl aminothiazolyl quinolone 8a showed strong inhibitory activity toward drug-resistant Staphylococcus aureus with MIC value of 0.0047 mM, which was 5-fold more active than that of norfloxacin. The highly active compound 8a exhibited negligible hemolysis, no significant toxicity in vitro and in vivo, low drug resistance, as well as rapidly bactericidal effects, which suggested its favorable druggability. Furthermore, compound 8a was able to effectively disrupt the integrity of the bacterial membrane, intercalate into DNA and inhibit the activity of topoisomerase IV, suggesting multitargeting mechanism of action. Compound 8a could form hydrogen bonds and hydrophobic interactions with DNA-topoisomerase IV complex, indicating the insertion of aminothiazolyl moiety was beneficial to improve antibacterial efficiency. These findings indicated that the active carbothioamido hydrazonyl aminothiazolyl quinolone 8a as a chemical therapeutic candidate demonstrated immense potential to tackle drug-resistant bacterial infections.
PubMed: 38944934
DOI: 10.1016/j.ejmech.2024.116626 -
Cytotherapy Jun 2024The prevalence of chronic wounds continues to be a burden in human medicine. Methicillin-resistant Staphylococcus aureus (MRSA) is commonly isolated from infected...
The mesenchymal stromal cell secretome promotes tissue regeneration and increases macrophage infiltration in acute and methicillin-resistant Staphylococcus aureus-infected skin wounds in vivo.
BACKGROUND AIMS
The prevalence of chronic wounds continues to be a burden in human medicine. Methicillin-resistant Staphylococcus aureus (MRSA) is commonly isolated from infected wounds. MRSA infections primarily delay healing by impairing local immune cell functions. This study aimed to investigate the potential of mesenchymal stromal cell (MSC)-secreted bioactive factors, defined as the secretome, to improve innate immune responses in vivo. MSCs were isolated from the bone marrow of horses, which serve as valuable translational models for wound healing. The MSC secretome, collected as conditioned medium (CM), was evaluated in vivo using mouse models of acute and MRSA-infected skin wounds.
METHODS
Punch biopsies were used to create two full-thickness skin wounds on the back of each mouse. Acute wounds were treated daily with control medium or bone marrow-derived MSC (BM-MSC) CM. The antibiotic mupirocin was administered as a positive control for the MRSA-infected wound experiments. Wounds were photographed daily, and wound images were measured to determine the rate of closure. Trichrome staining was carried out to examine wound tissue histologically, and immunofluorescence antibody binding was used to assess immune cell infiltration. Wounds in the MRSA-infected model were swabbed for quantification of bacterial load.
RESULTS
Acute wounds treated with BM-MSC CM showed accelerated wound closure compared with controls, as illustrated by enhanced granulation tissue formation and resolution, increased vasculature and regeneration of hair follicles. This treatment also led to increased neutrophil and macrophage infiltration. Chronic MRSA-infected wounds treated with BM-MSC CM showed reduced bacterial load accompanied by better resolution of granulation tissue formation and increased infiltration of pro-healing M2 macrophages compared with control-treated infected wounds.
CONCLUSIONS
Collectively, our findings indicate that BM-MSC CM exerts pro-healing, immunomodulatory and anti-bacterial effects on wound healing in vivo, validating further exploration of the MSC secretome as a novel treatment option to improve healing of both acute and chronic wounds, especially those infected with antibiotic-resistant bacteria.
PubMed: 38944795
DOI: 10.1016/j.jcyt.2024.06.007 -
Mymensingh Medical Journal : MMJ Jul 2024Water related diseases are of great concern in developing countries like Bangladesh. Every year, many people die due to consumption of unsafe drinking water. In order to... (Observational Study)
Observational Study
Water related diseases are of great concern in developing countries like Bangladesh. Every year, many people die due to consumption of unsafe drinking water. In order to protect public health it is compulsory that the accessible drinking water should be maximum quality. In this descriptive observational study 150 samples of bottled water and 150 jar water samples were collected from different shops and restaurants. Each sample were filtered through a membrane filter and then placed on MacConkey agar media for total and fecal coliform count and 0.1 ml of water spread on nutrient agar media for heterotrophic plate count (HPC). Among 150 bottled water samples 11 (7.33%) were culture positive and 92 (61.33%) were culture positive in 150 jar water samples. Out of 150 jar water samples 38 (25.33%) were total coliform and among them 19 (12.67%) were fecal coliform. Among 300 water samples 55 (53.40%) samples showed HPC greater than 500 CFU/ml. A total of 9 bacterial isolates: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter spp. CONS, Aeromonas spp., Enterobacter spp., Klebsiella spp. and Citrobacter were found.
Topics: Drinking Water; Water Microbiology; Humans; Bangladesh
PubMed: 38944733
DOI: No ID Found -
Mymensingh Medical Journal : MMJ Jul 2024Antibiotics' usefulness is threatened by multi-drugs resistance in harmful microorganisms because of abuse and regulatory problems. Emerging microbes, resistance...
Antibiotics' usefulness is threatened by multi-drugs resistance in harmful microorganisms because of abuse and regulatory problems. Emerging microbes, resistance mechanisms and antimicrobial drugs all require extensive investigation. Evaluation of the in vitro antibacterial activity of Methanolic extracts isolated from Black pepper seeds (Piper nigrum L.) against two infection causing pathogens, Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa. From July 2022 and June 2023, this experimental study was conducted at the Mymensingh Medical College's Department of Pharmacology and Therapeutics in conjunction with the Department of Microbiology. The solvents Methanol and 10.0% Di-Methyl Sulfoxide (DMSO) were used to make the extract. Using the disc diffusion and broth dilution methods, the antibacterial activity of methanolic extract of black pepper seeds (MBPE) was evaluated at various doses. Using the broth dilution procedure, the conventional antibiotic Ciprofloxacin was utilized, and the outcome was contrasted with that of Methanol extracts. Methanolic extract of black pepper seeds (MBPE) at seven distinct concentrations (100, 80, 60, 40, 20, 10 and 5mg/ml) were utilized, then later in chosen concentrations as needed to confirm the extracts' more precise margin of antimicrobial sensitivity. At 80mg/ml and above doses of the MBPE, it had an inhibitory impact against the aforementioned microorganisms. For Staphylococcus aureus and Pseudomonas aeruginosa the MIC were 60 and 70mg/ml in MBPE respectively. As of the MIC of Ciprofloxacin was 1μg/ml against Staphylococcus aureus and 1.5μg/ml for Pseudomonas aeruginosa. In comparison to MICs of MBPE for the test organisms, the MIC of Ciprofloxacin was the lowest. This study clearly shows that Staphylococcus aureus and Pseudomonas aeruginosa are sensitive to the methanolic extract of black pepper seeds' antibacterial properties.
Topics: Piper nigrum; Pseudomonas aeruginosa; Plant Extracts; Staphylococcus aureus; Seeds; Anti-Bacterial Agents; Microbial Sensitivity Tests; Methanol
PubMed: 38944702
DOI: No ID Found -
Microbes and Infection Jun 2024Antimicrobial treatment of methicillin-resistant Staphylococcus pseudintermedius associated with canine wounds represents an important challenge. The aim of this study...
Antimicrobial treatment of methicillin-resistant Staphylococcus pseudintermedius associated with canine wounds represents an important challenge. The aim of this study was to create a canine wound infection model, Lubbock Chronic Wound Biofilm (LCWB), with a focus on S. pseudintermedius, drawing inspiration from the established human model involving S. aureus. Methicillin-resistant S. pseudintermedius 115 (MRSP) and Pseudomonas aeruginosa 700 strains, isolated from dog wounds, were used to set up the LCWB at 24, 48 and 72h. The LCWBs were evaluated in terms of volume, weight, and microbial CFU/mg. The microbial spatial distribution in the LCWBs was assessed by SEM and CLSM imaging. The best incubation time for the LCWB production in terms of volume (3.38 cm ± 0.13), weight (0.86 gr ± 0.02) and CFU/mg (up to 7.05 x 10 CFU/mg ± 2.89 x 10) was 48h. The SEM and CLSM images showed a major viable microbial colonization at 48h with a non-mixed bacteria with a prevalence of MRSP on the surface and P. aeruginosa 700 in the depth of the wound. The obtained findings demonstrate the capability of S. pseudintermedius to grow together P. aeruginosa in the LCWB model, representing the suitable model to reproduce the animal chronic wound in vitro.
PubMed: 38944110
DOI: 10.1016/j.micinf.2024.105384 -
Phytochemistry Jun 2024The genus Penicillium has provided us with the household antibiotic penicillin and the well-known lipid-lowering agent mevastatin. The strain Penicillium sp. SZ-1 was...
The genus Penicillium has provided us with the household antibiotic penicillin and the well-known lipid-lowering agent mevastatin. The strain Penicillium sp. SZ-1 was found to grow vigorously in an intact Pinus koraiensis seed, it is inferred that the strain may develop unique mechanisms associated with the biosynthesis of rare metabolites. Further fermentation of the strain on solid rice medium yielded thirteen undescribed compounds, including three andrastin-type meroterpenoids (1-3), two α- pyrone polyketides (4 and 5), and eight sesquicarane derivatives (6-13), along with seven known compounds (14-20). Their structures were determined by detailed analysis of the spectroscopic and spectrometric data (NMR and HRESIMS), in addition to comparisons of the experimental and calculated ECD data for absolute configurational assignments. The hemiacetal moiety in compounds 1 and 2 and the 3α-hydroxy group in compound 3 were rarely found in the andrastin-type meroterpenoid family. The sesquicaranes belong to a small group of sesquiterpenoid that are rarely reported. Bioassay study showed that compound 1 exhibited inhibitory effects against Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922 with MIC values of 64 and 32 μg/mL, respectively. In addition, compounds 1 and 3 displayed weak DPPH radical scavenging activities. The andrastins and sesquicaranes in this study enriched the structural diversity of these classes of terpenoids. Of note, this study is the first report on the metabolites of a fungus isolated from P. koraiensis seed.
PubMed: 38944099
DOI: 10.1016/j.phytochem.2024.114202 -
International Journal of Biological... Jun 2024Some of conventional wastewater disinfectants can have a harmful influence on the environment as well as human health. The aim of this investigation was synthesis and...
Some of conventional wastewater disinfectants can have a harmful influence on the environment as well as human health. The aim of this investigation was synthesis and characterizes ecofriendly pectin/hydroxyethyl cellulose (HEC)/clay and pectin/HEC/clay incorporated with titanium dioxide nanoparticles (TiONPs) and use the prepared bionanocomposite as microbial disinfectants for real wastewater. Pectin/HEC/clay and pectin/HEC/clay/TiO bionanocomposite were characterized by various methods including X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier-transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA). Mechanical properties and water vapor permeability (WVP) were carried out. The results of SEM showed that, the prepared bionanocomposite had a smooth surface. Additionally, TiO nanoparticles to the pectin/HEC/clay composites may lead to changes in the FTIR spectrum. The intensity of XRD peaks indicated that, TiONPs was small size crystallite. TGA illustrated that pectin has moderate thermal stability, while HEC generally exhibits good thermal stability. The TEM showed that, TiO nanoparticles have diameters <25 nm. On the other hand, antimicrobial activities of pectin/HEC/clay against Escherichia coli (E. coli), Staphylococcus aureus and Candida albicans have been enhanced by adding TiONPs. The minimum inhibitory concentration (MIC) of pectin/HEC/clay/TiO against E. coli was 200 mg/mL. Moreover, complete eradication of E. coli, Salmonella and Candida spp. from real wastewater was observed by using pectin/HEC/clay/TiO bionanocomposite. Finally, it can be concluded that, the synthesized bionanocomposite is environmentally friendly and considered an excellent disinfectant matter for removal of the microbial pathogens from wastewater to safely reuse.
PubMed: 38944095
DOI: 10.1016/j.ijbiomac.2024.133511 -
Veterinary Immunology and... Jun 2024Mastitis, an inflammation of the mammary gland affecting milk production and quality in dairy herds, is often associated with Staphylococcus spp. in goats. Neutrophils...
Mastitis, an inflammation of the mammary gland affecting milk production and quality in dairy herds, is often associated with Staphylococcus spp. in goats. Neutrophils are crucial in combating infections by migrating into milk and deploying various defense strategies, including the release of neutrophil extracellular traps (NETs) composed of DNA, histones, and bactericidal proteins. This study investigated whether NETs are released by goat neutrophils stimulated in vitro by Staphylococcus aureus and Staphylococcus warneri, two common pathogens of goat mastitis. PMNs were isolated from blood from healthy adult goats. We evaluated goat NET formation by stimulating cells with: phorbol 12-myristate 13-acetate (PMA) as a positive control, cytochalasin for inhibition of actin polymerization, S. aureus, and S. warneri. NET formation was observed in response to chemical stimulation and bacterial presence, effectively trapping pathogens. Variations in NET formation between S. aureus and S. warneri suggest pathogen-specific responses. These findings suggest that the formation of NETs may be an important complementary mechanism in the defense against mastitis in goats. In conclusion, this study unveils a novel defense mechanism in goats, indicating the role of NETs against S. aureus and S. warneri in mastitis.
PubMed: 38943998
DOI: 10.1016/j.vetimm.2024.110793