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Cureus May 2024The association of s with vasculitis remains relatively rare and poorly understood. In this report, we present a case of Methicillin-sensitive (MSSA)-associated...
The association of s with vasculitis remains relatively rare and poorly understood. In this report, we present a case of Methicillin-sensitive (MSSA)-associated leukocytoclastic vasculitis (LCV) following a surgical site infection, adding to the limited body of knowledge on this intriguing clinical entity. A 52-year-old male with a medical history significant for type 2 diabetes mellitus, hypertension, hyperlipidemia, and coronary artery disease presented with progressively worsening generalized petechial rash and migratory joint pains with associated joint swelling. The patient's symptoms began following surgical repair for a rectus abdominis incisional hernia with mesh placement that was complicated by an abdominal wall abscess at the surgical site, prompting drain placement. Cultures from the abscess aspirate revealed Methicillin-sensitive infection. A punch biopsy of the petechial lesions revealed findings consistent with leukocytoclastic vasculitis. The rash and joint pains resolved approximately one week after initiation of treatment with antibiotics and steroids. This case sheds light on the rare but clinically significant association between Methicillin-sensitive infection and leukocytoclastic vasculitis, particularly following surgical site infections. The prompt recognition and treatment of underlying MSSA infection, along with the targeted management of LCV, resulted in the resolution of symptoms in our patient. This case emphasizes the importance of a comprehensive diagnostic approach and highlights the efficacy of antibiotic therapy in mitigating MSSA-associated vasculitic manifestations.
PubMed: 38910712
DOI: 10.7759/cureus.60867 -
Chinese Medicine Jun 2024Rising resistance to antimicrobials, particularly in the case of methicillin-resistant Staphylococcus aureus (MRSA), represents a formidable global health challenge....
BACKGROUND
Rising resistance to antimicrobials, particularly in the case of methicillin-resistant Staphylococcus aureus (MRSA), represents a formidable global health challenge. Consequently, it is imperative to develop new antimicrobial solutions. This study evaluated 68 Chinese medicinal plants renowned for their historical applications in treating infectious diseases.
METHODS
The antimicrobial efficacy of medicinal plants were evaluated by determining their minimum inhibitory concentration (MIC) against MRSA. Safety profiles were assessed on human colorectal adenocarcinoma (Caco-2) and hepatocellular carcinoma (HepG2) cells. Mechanistic insights were obtained through fluorescence and transmission electron microscopy (FM and TEM). Synergistic effects with vancomycin were investigated using the Fractional Inhibitory Concentration Index (FICI).
RESULTS
Rheum palmatum L., Arctium lappa L. and Paeonia suffructicosaas Andr. have emerged as potential candidates with potent anti-MRSA properties, with an impressive low MIC of 7.8 µg/mL, comparable to the 2 µg/mL MIC of vancomycin served as the antibiotic control. Crucially, these candidates demonstrated significant safety profiles when evaluated on Caco-2 and HepG2 cells. Even at 16 times the MIC, the cell viability ranged from 83.3% to 95.7%, highlighting their potential safety. FM and TEM revealed a diverse array of actions against MRSA, such as disrupting the cell wall and membrane, interference with nucleoids, and inducing morphological alterations resembling pseudo-multicellular structures in MRSA. Additionally, the synergy between vancomycin and these three plant extracts was evident against MRSA (FICI < 0.5). Notably, aqueous extract of R. palmatum at 1/4 MIC significantly reduced the vancomycin MIC from 2 µg/mL to 0.03 µg/mL, making a remarkable 67-fold decrease.
CONCLUSIONS
This study unveil new insights into the mechanistic actions and pleiotropic antibacterial effectiveness of these medicinal plants against resistant bacteria, providing robust evidence for their potential use as standalone or in conjunction with antibiotics, to effectively combat antimicrobial resistance, particularly against MRSA.
PubMed: 38909250
DOI: 10.1186/s13020-024-00960-8 -
Bioorganic & Medicinal Chemistry Jul 2024The antimicrobial activity of new acid-functionalized porphyrins, with or without ultra-high irradiance, was investigated. Antibacterial efficacy was evaluated against...
Synthesis and characterization of new acid-functionalized porphyrins displaying antimicrobial activity against gram positive bacteria, yeasts and filamentous fungi with or without ultra-high irradiance.
The antimicrobial activity of new acid-functionalized porphyrins, with or without ultra-high irradiance, was investigated. Antibacterial efficacy was evaluated against Staphylococcus aureus (methicillin-resistant or methicillin-sensitive strains) and antifungal efficacy was evaluated against the yeast Candida albicans and the filamentous fungi Aspergillus fumigatus. Overall, the porphyrins tested are more effective against S. aureus. The best results were obtained with zinc diacid porphyrins 4 and 5 after only 3 min of ultra-high irradiation (500 mW/cm, 405 nm), demonstrating that acid-functionalized porphyrins are promising as novel antimicrobial drugs for surface disinfection.
Topics: Microbial Sensitivity Tests; Porphyrins; Aspergillus fumigatus; Candida albicans; Antifungal Agents; Anti-Bacterial Agents; Gram-Positive Bacteria; Staphylococcus aureus; Structure-Activity Relationship; Molecular Structure; Dose-Response Relationship, Drug; Fungi
PubMed: 38906069
DOI: 10.1016/j.bmc.2024.117810 -
PeerJ 2024Pathogenic bacteria are the cause of most skin diseases, but issues such as resistance and environmental degradation drive the need to research alternative treatments....
BACKGROUND
Pathogenic bacteria are the cause of most skin diseases, but issues such as resistance and environmental degradation drive the need to research alternative treatments. It is reported that silk cocoon extract possesses antioxidant properties. During silk processing, the degumming of silk cocoons creates a byproduct that contains natural active substances. These substances were found to have inhibitory effects on bacterial growth, DNA synthesis, the pathogenesis of hemolysis, and biofilm formation. Thus, silk cocoon extracts can be used in therapeutic applications for the prevention and treatment of skin pathogenic bacterial infections.
METHODS
The extract of silk cocoons with pupae (SCP) and silk cocoons without pupae (SCWP) were obtained by boiling with distilled water for 9 h and 12 h, and were compared to silkworm pupae (SP) extract that was boiled for 1 h. The active compounds in the extracts, including gallic acid and quercetin, were determined using high-performance liquid chromatography (HPLC). Furthermore, the total phenolic and flavonoid content in the extracts were investigated using the Folin-Ciocalteu method and the aluminum chloride colorimetric method, respectively. To assess antioxidant activity, the extracts were evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Additionally, the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of silk extracts and phytochemical compounds were determined against skin pathogenic bacteria. This study assessed the effects of the extracts and phytochemical compounds on growth inhibition, biofilm formation, hemolysis protection, and DNA synthesis of bacteria.
RESULTS
The HPLC characterization of the silk extracts showed gallic acid levels to be the highest, especially in SCP (8.638-31.605 mg/g extract) and SP (64.530 mg/g extract); whereas quercetin compound was only detected in SCWP (0.021-0.031 mg/g extract). The total phenolics and flavonoids in silk extracts exhibited antioxidant and antimicrobial activity. Additionally, SCP at 9 h and 12 h revealed the highest anti-bacterial activity, with the lowest MIC and MBC of 50-100 mg/mL against skin pathogenic bacteria including , methicillin-resistant (MRSA), and . Hence, SCP extract and non-sericin compounds containing gallic acid and quercetin exhibited the strongest inhibition of both growth and DNA synthesis on skin pathogenic bacteria. The suppression of bacterial pathogenesis, including preformed and matured biofilms, and hemolysis activity, were also revealed in SCP extract and non-sericin compounds. The results show that the byproduct of silk processing can serve as an alternative source of natural phenolic and flavonoid antioxidants that can be used in therapeutic applications for the prevention and treatment of pathogenic bacterial skin infections.
Topics: Animals; Bombyx; Antioxidants; Silk; Anti-Bacterial Agents; Biofilms; Pupa; Free Radicals; Microbial Sensitivity Tests; Hemolysis
PubMed: 38903886
DOI: 10.7717/peerj.17490 -
PloS One 2024Implant-associated osteomyelitis remains a major orthopaedic problem. As neutrophil swarming to the surgical site is a critical host response to prevent infection,...
Implant-associated osteomyelitis remains a major orthopaedic problem. As neutrophil swarming to the surgical site is a critical host response to prevent infection, visualization and quantification of this dynamic behavior at the native microenvironment of infection will elucidate previously unrecognized mechanisms central to understanding the host response. We recently developed longitudinal intravital imaging of the bone marrow (LIMB) to visualize host cells and fluorescent S. aureus on a contaminated transfemoral implant in live mice, which allows for direct visualization of bacteria colonization of the implant and host cellular responses using two-photon laser scanning microscopy. To the end of rigorous and reproducible quantitative outcomes of neutrophil swarming kinetics in this model, we developed a protocol for robust segmentation, tracking, and quantifications of neutrophil dynamics adapted from Trainable Weka Segmentation and TrackMate, two readily available Fiji/ImageJ plugins. In this work, Catchup mice with tdTomato expressing neutrophils received a transfemoral pin with or without ECFP/EGFP-expressing USA300 methicillin-resistant Staphylococcus aureus (MRSA) to obtain 30-minute LIMB videos at 2-, 4-, and 6-hours post-implantation. The developed semi-automated neutrophil tracking protocol was executed independently by two users to quantify the distance, displacement, speed, velocity, and directionality of the target cells. The results revealed high inter-user reliability for all outcomes (ICC > 0.96; p > 0.05). Consistent with the established paradigm on increased neutrophil swarming during active infection, the results also demonstrated increased neutrophil speed and velocity at all measured time points, and increased displacement at later time points (6 hours) in infected versus uninfected mice (p < 0.05). Neutrophils and bacteria also exhibit directionality during migration in the infected mice. The semi-automated cell tracking protocol provides a streamlined approach to robustly identify and track individual cells across diverse experimental settings and eliminates inter-observer variability.
Topics: Animals; Neutrophils; Mice; Femur; Cell Tracking; Staphylococcal Infections; Disease Models, Animal; Osteomyelitis; Methicillin-Resistant Staphylococcus aureus; Prosthesis-Related Infections; Prostheses and Implants; Staphylococcus aureus; Female
PubMed: 38900759
DOI: 10.1371/journal.pone.0296140 -
Antimicrobial Agents and Chemotherapy Jun 2024Delafloxacin, a fluoroquinolone antibiotic to treat skin infections, exhibits a broad-spectrum antimicrobial activity. The first randomized, open-label phase I clinical...
Delafloxacin, a fluoroquinolone antibiotic to treat skin infections, exhibits a broad-spectrum antimicrobial activity. The first randomized, open-label phase I clinical trial was conducted to assess the safety and pharmacokinetics (PK) of intravenous delafloxacin in the Chinese population. A population pharmacokinetic (PopPK) model based on the clinical trial was conducted by NONMEM software. Monte Carlo simulation was performed to evaluate the antibacterial effects of delafloxacin at different doses in different Chinese populations. The PK characteristics of delafloxacin were best described by a three-compartment model with mixed linear and nonlinear clearance. Body weight was included as a covariate in the model. We simulated the AUC in a steady state at five doses in patient groups of various weights. The results indicated that for patients weighing 70 kg and treated with methicillin-resistant (MRSA) infections, a minimum dose of 300 mg achieved a PTA > 90% at MIC of 0.25 µg/mL, suggesting an ideal bactericidal effect. For patients weighing less than 60 kg, a dose of 200 mg achieved a PTA > 90% at MIC of 0.25 µg/mL, also suggesting an ideal bactericidal effect. Additionally, this trial demonstrated the high safety of delafloxacin in single-dose and multiple-dose groups of Chinese. Delafloxacin (300 mg, q12h, iv) was recommended for achieving optimal efficacy in Chinese bacterial skin infections patients. To ensure optimal efficacy, an individualized dose of 200 mg (q12h, iv) could be advised for patients weighing less than 60 kg, and 300 mg (q12h, iv) for those weighing more than 60 kg.
PubMed: 38899925
DOI: 10.1128/aac.00428-24 -
BioMed Research International 2024In a research experiment, 48 male Wistar rats were anesthetized and second-degree burns were induced on their backs. The rats' wounds were then uniformly inoculated with...
MATERIALS AND METHODS
In a research experiment, 48 male Wistar rats were anesthetized and second-degree burns were induced on their backs. The rats' wounds were then uniformly inoculated with MRSA. Various treatments were applied to the burn wounds daily, including Myrtus ointment, silver nanoparticles, silver nanoparticles-Myrtus ointment, silver sulfadiazine-Myrtus ointment, silver sulfadiazine 1%, mupirocin ointment, and a positive control. The study measured the antimicrobial effects, wound area, percentage of wound healing, antioxidant capacities, malondialdehyde, and nitric oxide concentrations in the serum of the rats. Data analysis was performed using GraphPad software, with one-way ANOVA and Tukey's tests used to determine the statistical significance of the results.
RESULTS
Rats treated with Myrtus ointment, silver nanoparticles-Myrtus ointment, and mupirocin had reduced bacterial growth compared to the positive control group, nanoparticle ointment, and silver sulfadiazine ( < 0.05). The wound area of the Myrtus ointment group decreased significantly on the seventh and fourteenth days, as well as the level of MDA and nitric oxide, compared to the other groups. In Myrtus and silver sulfadiazine-Myrtus ointment increased the thickness of the epidermis and dermis compared to the other groups.
CONCLUSION
Based on the anti-inflammatory, antimicrobial, and wound healing properties of Myrtus, with further studies, an ointment of this plant may be used as a main or complementary treatment for burn wound infections caused by MRSA.
Topics: Animals; Wound Healing; Methicillin-Resistant Staphylococcus aureus; Burns; Plant Extracts; Male; Ointments; Rats; Rats, Wistar; Anti-Inflammatory Agents; Plant Leaves; Myrtus; Anti-Infective Agents; Wound Infection; Staphylococcal Infections; Metal Nanoparticles; Silver Sulfadiazine
PubMed: 38899039
DOI: 10.1155/2024/6758817 -
Clinical Microbiology and Infection :... Jun 2024This review aims to explore the characteristics of outbreaks of community-acquired community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) in low... (Review)
Review
OBJECTIVES
This review aims to explore the characteristics of outbreaks of community-acquired community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) in low prevalence areas, to understand the factors involved in its rise, and to translate this knowledge into public health policy and further research needs.
SOURCES
PubMed, EMBASE and Google Scholar were searched using combinations of the terms "transmission", "acquisition", "CA-MRSA" "MRSA", "community-acquired", "low prevalence", "genomic", "outbreak", "colonisation" and "carriage". Wherever evidence was limited, additional articles were sought specifically, via PubMed searches. Papers where materials were not available in English were excluded.
CONTENT
Community-acquired, community onset MRSA infection presents a significant public health challenge, even in low prevalence areas; where MRSA rates are historically lower. Despite successes in reducing hospital-onset MRSA (HO-MRSA), CO-MRSA rates are increasing globally, with a need to understand this trend, and the potential risk factors for re-emergence. Challenges in defining low prevalence areas and the significance of exposure to various risk factors for community acquisition, such as healthcare settings, travel, livestock, and environmental factors, are discussed. The importance of genomic surveillance in identifying outbreak strains and understanding the transmission dynamics is highlighted, along with the need for robust public health policies and control measures.
IMPLICATIONS
The findings emphasise the complexity of CO-MRSA transmission and the necessity of a multifaceted approach in low prevalence areas. This includes integrated and systematic surveillance of HO-, CO-, and livestock-associated MRSA (LA-MRSA), as has been effective in some Northern European countries. The evolution of CO-MRSA underscores the need for global collaboration, routine genomic surveillance, and comprehensive antimicrobial stewardship to mitigate the rise of CO-MRSA and address the broader challenge of antimicrobial resistance. These efforts are crucial for maintaining low MRSA prevalence and managing the increasing burden of CO-MRSA in both low and higher prevalence regions.
PubMed: 38897351
DOI: 10.1016/j.cmi.2024.06.006 -
Acta Biomaterialia Jun 2024Antimicrobial phototherapy has gained recognition as a promising approach for addressing bacterial biofilms, however, its effectiveness is often impeded by the robust...
Antimicrobial phototherapy has gained recognition as a promising approach for addressing bacterial biofilms, however, its effectiveness is often impeded by the robust physical and chemical defenses of the biofilms. Traditional antibacterial nanoplatforms face challenges in breaching the extracellular polymeric substances (EPS) barrier to efficiently deliver photosensitizers deep into biofilms. Moreover, the prevalent hypoxia within biofilms restricts the success of oxygen-reliant phototherapy. In this study, we engineered a soft mesoporous organosilica nanoplatform (SMONs) by incorporating polyethylene glycol (PEG), catalase (CAT), and indocyanine green (ICG), forming SMONs-PEG-CAT-ICG (SPCI). We compared the antimicrobial efficacy of SPCI with more rigid nanoplatforms. Our results demonstrate that SPCI's unique flexible mechanical properties enable it to navigate through biofilm barriers, markedly enhancing ICG penetration in methicillin-resistant Staphylococcus aureus (MRSA) biofilms. Notably, in a murine subcutaneous MRSA biofilm infection model, SPCI showed superior biofilm penetration and pharmacokinetic benefits over its rigid counterparts. The embedded catalase in SPCI effectively converts excess HO present in infected tissues into O, alleviating hypoxia and significantly boosting the antibacterial performance of phototherapy. Both in vitro and in vivo experiments confirm that SPCI surpasses traditional rigid nanoplatforms in overcoming biofilm barriers, offering improved treatment outcomes for infections associated with bacterial biofilms. This study presents a viable strategy for managing bacterial biofilm-induced diseases by leveraging the unique attributes of a soft mesoporous organosilica-based nanoplatform. STATEMENT OF SIGNIFICANCE: This research introduces an innovative antimicrobial phototherapy soft nanoplatform that overcomes the inherent limitations posed by the protective barriers of bacterial biofilms. By soft nanoplatform with flexible mechanical properties, we enhance the penetration and delivery of photosensitizers into biofilms. The inclusion of catalase within this soft nanoplatform addresses the hypoxia in biofilms by converting hydrogen peroxide into oxygen in infected tissues, thereby amplifying the antibacterial effectiveness of phototherapy. Compared to traditional rigid nanoplatforms, this flexible nanoplatform not only promotes the delivery of therapeutic agents but also sets a new direction for treating bacterial biofilm infections, offering significant implications for future antimicrobial therapies.
PubMed: 38897337
DOI: 10.1016/j.actbio.2024.06.018 -
Frontiers in Pediatrics 2024infections are a significant cause of morbidity and mortality in pediatric populations worldwide. The Staphylo Research Network conducted an extensive study on...
BACKGROUND
infections are a significant cause of morbidity and mortality in pediatric populations worldwide. The Staphylo Research Network conducted an extensive study on pediatric patients across Colombia from 2018 to 2021. The aim of this study was to describe the epidemiological and microbiological characteristics of in this patient group.
METHODS
We analyzed isolates from WHONET-reporting centers. An "event" was a positive culture isolation in a previously negative individual after 2 weeks. We studied center characteristics, age distribution, infection type, and antibiotic susceptibilities, comparing methicillin sensitive (MSSA) and resistant (MRSA) isolates.
RESULTS
Isolates from 20 centers across 7 Colombian cities were included. Most centers (80%) served both adults and children, with 55% offering oncology services and 85% having a PICU. We registered 8,157 culture isolations from 5,384 events (3,345 MSSA and 1,961 MRSA) in 4,821 patients, with a median age of 5 years. Blood (26.2%) and skin/soft tissue (18.6%) were the most common infection sources. Most isolates per event remained susceptible to oxacillin (63.2%), clindamycin (94.3%), and TMP-SMX (98.3%). MRSA prevalence varied by city (<0.001), with slightly higher rates observed in exclusively pediatric hospitals. In contrast, the MRSA rate was somewhat lower in centers with Antimicrobial Stewardship Program (ASP). MRSA was predominantly isolated from osteoarticular infections and multiple foci, while MSSA was more frequently associated with recurrent infections compared to MRSA.
CONCLUSIONS
This is the largest study of pediatric infections in Colombia. We found MSSA predominance, but resistance have important regional variations. remains susceptible to other commonly used antibiotics such as TMP-SMX and clindamycin. Ongoing monitoring of infections is vital for understanding their behavior in children. Prospective studies within the Staphylored LATAM are underway for a more comprehensive clinical and genetic characterization.
PubMed: 38895192
DOI: 10.3389/fped.2024.1386310