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BMC Microbiology Jun 2024Multi-drug-resistant Staphylococcus aureus infections necessitate novel antibiotic development. D-3263, a transient receptor potential melastatin member 8 (TRPM8)...
Multi-drug-resistant Staphylococcus aureus infections necessitate novel antibiotic development. D-3263, a transient receptor potential melastatin member 8 (TRPM8) agonist, has potential antineoplastic properties. Here, we reported the antibacterial and antibiofilm activities of D-3263. Minimum inhibitory concentrations (MICs) against S. aureus, Enterococcus faecalis and E. faecium were ≤ 50 µM. D-3263 exhibited bactericidal effects against clinical methicillin-resistant S. aureus (MRSA) and E. faecalis strains at 4× MIC. Subinhibitory D-3263 concentrations effectively inhibited S. aureus and E. faecalis biofilms, with higher concentrations also clearing mature biofilms. Proteomic analysis revealed differential expression of 29 proteins under 1/2 × MIC D-3263, influencing amino acid biosynthesis and carbohydrate metabolism. Additionally, D-3263 enhanced membrane permeability of S. aureus and E. faecalis. Bacterial membrane phospholipids phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and cardiolipin (CL) dose-dependently increased D-3263 MICs. Overall, our data suggested that D-3263 exhibited potent antibacterial and antibiofilm activities against S. aureus by targeting the cell membrane.
Topics: Biofilms; Anti-Bacterial Agents; Microbial Sensitivity Tests; Staphylococcus aureus; Enterococcus faecalis; Methicillin-Resistant Staphylococcus aureus; Bacterial Proteins; Proteomics; Humans; Cell Membrane; Cell Membrane Permeability
PubMed: 38926818
DOI: 10.1186/s12866-024-03377-3 -
The British Journal of Ophthalmology Jun 2024To report an epidemiological update of bacterial keratitis (BK) in a tertiary ophthalmology centre over 20 months compared with a previous study on the same timeframe...
AIMS
To report an epidemiological update of bacterial keratitis (BK) in a tertiary ophthalmology centre over 20 months compared with a previous study on the same timeframe from 1998 to 1999.
METHODS
354 patients with BK documented by microbiological corneal scraping or resolutive under antibiotics treatment from January 2020 to September 2021 were analysed retrospectively.
RESULTS
One or several risk factors were found in 95.2% of patients: contact lens wear (45.2%), ocular surface disease (25.0%), systemic disease (21.8%), ocular trauma (11.9%) and ocular surgery (8.8%). The positivity rate of corneal scrapings was 82.5%, with 18.2% polybacterial. One hundred seventy-five (59.9%) bacteria were Gram-negative, and 117 (40.1%) were Gram-positive. The most common bacteria were (32.5%), spp (18.1%) and (8.2%). Final visual acuity (logarithm of the minimum angle of resolution) was associated with age (r=+0.48; p=0.0001), infiltrate size (r=+0.32; p<0.0001), ocular surface disease (r=+0.13; p=0.03), ocular trauma (r=-0.14; p=0.02) and contact lens wear (r=-0.26; p<0.0001). Gram-negative bacteria were responsible for deeper (r=+0.18; p=0.004) and more extensive infiltrates (r=+0.18; p=0.004) in younger patients (r=-0.19; p=0.003). Compared with the previous period, the positivity rate of corneal scrapings and the proportion of Gram-negative bacteria, especially spp, increased. All and spp were sensitive to quinolones, and all were sensitive to both quinolones and methicillin.
CONCLUSION
Contact lens wear remained the leading risk factor. The bacteria distribution was reversed, with a predominance of Gram-negative bacteria and increased spp.
PubMed: 38925906
DOI: 10.1136/bjo-2024-325261 -
Veterinary Medicine and Science Jul 2024Silica-sprayed tubes (SSTs) are often used to transport synovial fluid samples in equine practice. They promote the coagulation of the sample. The objective of the study...
INTRODUCTION
Silica-sprayed tubes (SSTs) are often used to transport synovial fluid samples in equine practice. They promote the coagulation of the sample. The objective of the study is to evaluate the effect of SST on bacterial culture.
MATERIALS AND METHODS
The study was divided into two parts: sterile saline (Part A) and synovial fluid (Part B). Four common bacteria associated with equine synovial sepsis were used: Streptococcus pyogenes, Escherichia coli, Staphylococcus aureus and methicillin-resistant S. aureus (MRSA). Three collection tubes were used: STT, plain (no-additives) and brain and heart infusion (BHI) broth. Bacteria were cultured in horse blood agar plates for 48 h. Outcome variables were negative culture, positive culture and total number of colony-forming units (CFUs). Statistical analysis was performed using Mann-Whitney U test, and significance was set at p < 0.05.
RESULTS
The total number of agar plates read was 1557 (779 saline; 778 synovial fluid). Total negative cultures were 25/779 on saline and 3/778 on synovial fluid. In broth, maximum growth CFU was achieved after 8 h for both saline and synovial fluid for all bacteria. S. pyogenesand E. coli produced a significantly lower number of CFU when in SST compared to plain or broth after 4 h, whereas S. aureus (American Type Culture Collection [ATCC] and MRSA) only after 24 h.
DISCUSSION
Silica-containing tubes reduced bacterial proliferation, whereas the use of a BHI broth provided the highest bacterial load in the sample. The use of SST may have a negative effect on bacterial proliferation in samples obtained from clinical cases.
Topics: Synovial Fluid; Animals; Horses; Silicon Dioxide; Specimen Handling; Escherichia coli; Staphylococcus aureus; Bacteriological Techniques; Streptococcus pyogenes; Methicillin-Resistant Staphylococcus aureus
PubMed: 38923315
DOI: 10.1002/vms3.1501 -
Marine Drugs May 2024Five new naphthalene derivatives dalesconosides A-D, F (-, ), a known synthetic analogue named dalesconoside E (), and eighteen known compounds (-) were isolated from...
Five new naphthalene derivatives dalesconosides A-D, F (-, ), a known synthetic analogue named dalesconoside E (), and eighteen known compounds (-) were isolated from MCZ-18, which is an endophytic fungus obtained from the Chinese mangrove plant . Differing from previously reported naphthalenes, compounds and were bearing a rare ribofuranoside substituted at C-1 and the 5-methyltetrahydrofuran-2,3-diol moiety, respectively. Their structures were determined by detailed nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analyses, while the absolute configurations were established by theoretical electronic circular dichroism (ECD) calculation. Compounds , , - and showed broad ranges of antimicrobial spectrum against five indicator test microorganisms (, Methicillin-resistant , , and ); especially, , and were most potent. The variations in structure and attendant biological activities provided fresh insights concerning structure-activity relationships for the naphthalene derivatives.
Topics: Naphthalenes; Microbial Sensitivity Tests; Structure-Activity Relationship; Magnetic Resonance Spectroscopy; Anti-Bacterial Agents; Candida albicans; Molecular Structure; Rhizophoraceae; Endophytes; Anti-Infective Agents
PubMed: 38921554
DOI: 10.3390/md22060242 -
International Journal of Nanomedicine 2024This research was to innovate a nanozyme-based therapeutic strategy that combines aggregation-induced emission (AIE) photosensitizers with copper nanozymes. This...
PURPOSE
This research was to innovate a nanozyme-based therapeutic strategy that combines aggregation-induced emission (AIE) photosensitizers with copper nanozymes. This approach is designed to address the hypoxic conditions often found in bacterial infections and aims to boost the effectiveness of photodynamic therapy (PDT) by ensuring sufficient oxygen supply for reactive oxygen species (ROS) generation.
METHODS
Our approach involved the synthesis of dihydroxyl triphenyl vinyl pyridine (DHTPY)-Cu@zoledronic acid (ZOL) nanozyme particles. We initially synthesized DHTPY and then combined it with copper nanozymes to form the DHTPY-Cu@ZOL composite. The nanozyme's size, morphology, and chemical properties were characterized using various techniques, including dynamic light scattering, transmission electron microscopy, and X-ray photoelectron spectroscopy. We conducted a series of in vitro and in vivo tests to evaluate the photodynamic, antibacterial, and wound-healing properties of the DHTPY-Cu@ZOL nanozymes, including their oxygen-generation capacity, ROS production, and antibacterial efficacy against methicillin-resistant Staphylococcus aureus (MRSA).
RESULTS
The DHTPY-Cu@ZOL exhibited proficient HO scavenging and oxygen generation, crucial for enhancing PDT in oxygen-deprived infection environments. Our in vitro analysis revealed a notable antibacterial effect against MRSA, suggesting the nanozymes' potential to disrupt bacterial cell membranes. Further, in vivo studies using a diabetic rat model with MRSA-infected wounds showed that DHTPY-Cu@ZOL markedly improved wound healing and reduced bacterial presence, underscoring its efficacy as a non-antibiotic approach for chronic infections.
CONCLUSION
Our study suggests that DHTPY-Cu@ZOL is a highly promising approach for combating antibiotic-resistant microbial pathogens and biofilms. The biocompatibility and stability of these nanozyme particles, coupled with their improved PDT efficacy position them as a promising candidate for clinical applications.
Topics: Photochemotherapy; Animals; Methicillin-Resistant Staphylococcus aureus; Copper; Anti-Bacterial Agents; Photosensitizing Agents; Wound Infection; Staphylococcal Infections; Reactive Oxygen Species; Imidazoles; Pyridines; Rats; Wound Healing; Male; Humans; Rats, Sprague-Dawley
PubMed: 38919773
DOI: 10.2147/IJN.S458520 -
Iranian Journal of Public Health Mar 2024Hospital refrigerators as essential food storage can be important source of food contamination. We aimed to investigate the frequency and antibiotic susceptibility of...
BACKGROUND
Hospital refrigerators as essential food storage can be important source of food contamination. We aimed to investigate the frequency and antibiotic susceptibility of the pathogenic bacteria in three hospital refrigerators in Tehran.
METHODS
This study was performed on 254 samples, collected from 60 refrigerators of the various wards of three hospitals, A, B, and C, in Tehran, Iran from 2020 to 2021. Following isolation and identification of isolates, the antibiotic susceptibility pattern was determined. PCR-based assays were used to screen the presence of antibiotic resistance genes of resistant isolates.
RESULTS
From 254 collected samples, 236 samples (92.9%) were contaminated. Most strains were isolated from refrigerators with poorly cleaned, temperatures above 8 °C in non-critical wards. Most bacteria belonging to Enterobacteriaceae (68.8%), followed by (11.9%), and (10.6%), while the frequency of non-Enterobacteriaceae isolates was 8.9%. The highest antibiotic resistant bacteria were in extended spectrum beta-lactamase (ESBL) 9.7%, vancomycin-resistant enterococci (VRE) 5.3%, methicillin-resistant (MRSE) 0.4%, and methicillin-resistant (MRSA) 0.4%, respectively. The , , and genes were found only in 10% of Enterobacteriaceae isolates. The gene was found in all non-Enterobacteriaceae isolates. The and genes were detected in antibiotic-resistant and .
CONCLUSION
Our findings suggests major concern about cross-contamination and the emergence of antibiotic-resistant isolates as a potential health threat with hospital refrigerators origin. More attention to hospital refrigerators cleaning is necessary to prevent foodborne diseases and nosocomial infections.
PubMed: 38919309
DOI: 10.18502/ijph.v53i3.15150 -
The Permanente Journal Jun 2024Wrist (TB) complex osteomyelitis is rare, with polymicrobial TB osteomyelitis even more uncommon. The authors describe an unusual case of polymicrobial TB wrist...
Wrist (TB) complex osteomyelitis is rare, with polymicrobial TB osteomyelitis even more uncommon. The authors describe an unusual case of polymicrobial TB wrist osteomyelitis. The case patient presented with a 2.5-year history of 2 insidiously growing nodules on his wrist. He underwent debridement, and tissue cultures grew methicillin-resistant , , and, later, TB complex. He was started on vancomycin, rifampin, isoniazid, pyrazinamide, and ethambutol with improvement in symptoms. This case emphasizes the importance of a broad differential and thorough workup for atypical presentations of osteomyelitis. Diagnosis of uncommon etiologies is essential for definitive treatment.
PubMed: 38919054
DOI: 10.7812/TPP/24.025 -
Antimicrobial Resistance and Infection... Jun 2024Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of mortality due to bacterial antimicrobial resistance. While S. aureus is common in skin...
BACKGROUND
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of mortality due to bacterial antimicrobial resistance. While S. aureus is common in skin and soft tissue infections (SSTI) in Africa, data on MRSA rates are scarce and reports vary widely across the continent (5%-80%). In this study, we describe the proportion of MRSA causing SSTI in Lambaréné, Gabon, over an 11-year period.
METHODS
We retrospectively analyzed data from 953 bacterial specimens collected from inpatients and outpatients with SSTI at the Albert Schweitzer Hospital, Lambaréné, Gabon, between 2009 and 2019. We determined temporal changes in the prevalence of MRSA and identified risk factors for SSTI with MRSA.
RESULTS
68% of all specimens with bacterial growth yielded S. aureus (n = 499/731), of which 7% (36/497) with antimicrobial susceptibility testing were identified as MRSA. Age above 18 years, admission to the surgical ward, and deep-seated infections were significantly associated with MRSA as the causative agent. After an initial decline from 7% in 2009, there was a marked increase in the proportion of MRSA among all S. aureus from SSTI from 3 to 20% between 2012 and 2019. The resistance rate to erythromycin was significantly higher in MRSA than in methicillin-susceptible S. aureus (73% vs. 10%), and clindamycin resistance was detected exclusively in MRSA isolates (8%).
CONCLUSION
The increasing proportion of MRSA causing SSTI over the 11-year period contrasts with many European countries where MRSA is on decline. Continuous surveillance of MRSA lineages in the hospital and community along with antibiotic stewardship programs could address the increasing trend of MRSA.
Topics: Humans; Methicillin-Resistant Staphylococcus aureus; Gabon; Soft Tissue Infections; Retrospective Studies; Male; Female; Adult; Adolescent; Middle Aged; Anti-Bacterial Agents; Young Adult; Microbial Sensitivity Tests; Prevalence; Child; Risk Factors; Staphylococcal Skin Infections; Staphylococcal Infections; Child, Preschool; Aged; Infant
PubMed: 38918863
DOI: 10.1186/s13756-024-01426-0 -
BMC Infectious Diseases Jun 2024CKD patients on hemodialysis (HD) with Staphylococcus aureus (SA) bacteremia present high morbidity, mortality and increased risk of MRSA. Vancomycin is the antibiotic...
Impact of Vancomycin trough levels monitoring on uncomplicated methilcillin-resistant Staphylococcus aureus bacteremia in chronic kidney disease on hemodialysis, retrospective cohort.
BACKGROUND
CKD patients on hemodialysis (HD) with Staphylococcus aureus (SA) bacteremia present high morbidity, mortality and increased risk of MRSA. Vancomycin is the antibiotic of choice in these cases, it has a narrow therapeutic margin and inadequate dosage generates a risk of toxicity, therefore, the recommendation is to dosage it through serum levels.
METHODS
This is a retrospective cohort study in 3 hospitals of third level of complexity in the city of Medellin in which there were differences in the measurement and implementation of vancomycin25 dosage based on trough levels (VL) in patients with chronic kidney disease on hemodialysis (CKD- HD) with uncomplicated bacteremia based infection by methilcillin-resistant Staphyloccocus aureus (MRSA). The primary outcome was the composite of hospital mortality, clinical response (fever, hemodynamic instability and altered consciousness), complications associated with bacteremia, or bacteriological response failure (positive cultures at first week follow-up) at 7 days. The composite variables were analyzed individually as secondary outcomes.
RESULTS
The main unadjusted outcome (OR 1.3, CI 0.6 - 2.7) and adjusted for age, Charlson index, loading dose, initial dose, dosing frequency and MIC to vancomycin (OR 1.2, CI 0.5 - 2.7). Regarding adjusted secondary outcomes: clinical response (OR 1.4 CI 0.3 - 5.8), death (OR 1.3 CI 0.3 - 4.6) and complications (OR 0.9, CI 0.37 - 2.2).
CONCLUSIONS
We conclude that the measurement of trough levels in patients with HD-CKD does not modify the composite outcome. The main limitation is the sample size and type of study, randomized control trials may be required to confirm the results presented.
Topics: Humans; Vancomycin; Retrospective Studies; Bacteremia; Staphylococcal Infections; Male; Renal Dialysis; Female; Renal Insufficiency, Chronic; Aged; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Anti-Bacterial Agents; Aged, 80 and over; Microbial Sensitivity Tests
PubMed: 38918705
DOI: 10.1186/s12879-024-08984-z -
Microbiology Spectrum Jun 2024Bacteremia is associated with significant morbidity and mortality. The emergence of bacteria with antimicrobial resistance (AMR) has further exacerbated the poor...
UNLABELLED
Bacteremia is associated with significant morbidity and mortality. The emergence of bacteria with antimicrobial resistance (AMR) has further exacerbated the poor outcomes associated with bacteremia. The Taiwan Surveillance of Antimicrobial Resistance (TSAR) program was established in 1998 to monitor bacterial epidemiology and antimicrobial resistance trends across all patient types and age groups. Between 2002 and 2020, a total of 14,539 non-duplicate bacteremia isolates were collected biennially from 29 hospitals during the months of July-September as part of the TSAR program. The three most common bacteremia agents were (31%), (13.6%), and (12.7%) overall. However, there was a steady increase in the proportions of and isolated from bacteremia cases (both < 0.001), while the proportions of spp. decreased. Regarding antimicrobial resistance, there was a notable increase in rates of third-generation cephalosporin and fluoroquinolone non-susceptibility among and , while the rates of carbapenem non-susceptibility were elevated but remained milder in these two species, especially in . Of concern is the alarming increase in vancomycin resistance among , rising from 10.0% in 2004 to 47.7% in 2020. In contrast, the prevalence of methicillin-resistant has remained stable at 51.2% overall. In conclusion, , with increasing third-generation cephalosporin and fluoroquinolone resistance, is the predominant cause of bacteremia in Taiwan during the 18-year surveillance. The escalating proportion of in bacteremia, coupled with a concurrent upsurge in vancomycin resistance, presents a therapeutic challenge in the recent decade.
IMPORTANCE
AMR surveillance not only enables the identification of regional variations but also supports the development of coordinated efforts to combat AMR on a global scale. The TSAR has been a biennial, government-endorsed, multicenter study focusing on pathogens isolated from inpatients and outpatients in Taiwan hospitals since 1998. Our report presents an 18-year comprehensive analysis on blood isolates in the 2002-2020 TSAR program. The study highlights an alarming increase in the proportion of causing bacteremia accompanied by elevated vancomycin resistance. It is worth noting that this trend differs from the observations in the United States and China. Understanding the composition of bacteria causing bacteremia, along with their prevalence of antimicrobial resistance, holds significant importance in establishing healthcare and research priorities. Additionally, this knowledge serves as a critical factor in evaluating the effectiveness of preventive interventions.
PubMed: 38916365
DOI: 10.1128/spectrum.00608-24