INTRODUCTION: It is hypothesized that systemically administered antibiotics penetrate wound sites more effectively during negative pressure wound therapy (NPWT). However, there is a lack of clinical data from patients who receive NPWT for deep sternal wound infection (DSWI) after open-heart surgery. Here, we evaluated vancomycin penetration into exudate in this patient group. PATIENTS AND METHODS: For this prospective observational study, we enrolled 10 consecutive patients treated with NPWT for post-sternotomy DSWI. On the first sampling day, serum and exudate samples were synchronously collected at 0 (pre-dose), 0.5, 1, 2, 3 and 6 h after vancomycin administration. On the following three consecutive days, additional samples were collected, only before vancomycin administration. RESULTS: The ratio of average vancomycin concentration in wound exudate to in serum was higher for free (unbound) (1.51 ± 0.53) than for total (bound + unbound) (0.91 ± 0.29) concentration (p = 0.049). The percentage of free vancomycin was higher in wound exudate than serum (0.79 ± 0.19 vs. 0.46 ± 0.16; p = 0.04). Good vancomycin wound penetration was maintained on the following three days (vancomycin trough exudate-to-serum concentration ratio > 1). The total hospital stay was significantly longer in patients with DSWI (46 ± 11.6 days) versus without DSWI (14 ± 11.7 days) (p < 0.001). There was no in-hospital or 90-day mortality. Two patients experienced late DSWI recurrence. All-cause mortality was 4.8% during a median follow-up of 2.5 years. CONCLUSION: Vancomycin effectively penetrates wound exudate in patients receiving NPWT for DSWI after open-heart surgery.The protocol for this study was registered at ClinicalTrials.gov on July 16, 2024 (NCT06506032).

• MeSH
• Anti-Bacterial Agents * pharmacokinetics   administration & dosage   MeSH
• Exudates and Transudates metabolism   microbiology   MeSH
• Surgical Wound Infection * MeSH
• Cardiac Surgical Procedures * adverse effects   MeSH
• Middle Aged MeSH
• Humans MeSH
• Prospective Studies MeSH
• Aged MeSH
• Sternotomy * adverse effects   MeSH
• Sternum surgery   MeSH
• Negative-Pressure Wound Therapy * methods   MeSH
• Vancomycin * administration & dosage   pharmacokinetics   MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Observational Study MeSH

This study aimed to develop a vancomycin population pharmacokinetic model in obese adult patients treated with intermittent haemodialysis and propose a model-based loading dose strategy ensuring attainment of newly recommended AUC-based PK/PD target. Retrospective cross-sectional analysis was performed among obese haemodialysis dependent adult patients treated with intravenous vancomycin. A pharmacokinetic population model was developed using a nonlinear mixed-effects modelling approach and Monte Carlo simulations were used to identify the optimal loading dose for PK/PD target attainment during the first 48 h of treatment. Therapeutic drug monitoring data from 27 patients with a BMI of 30.2-52.9 kg/m2 were analysed. Among all tested variables, only LBM as a covariate of vancomycin Vd significantly improved the model, while vancomycin CL did not correlate with any of the tested variables. The median (IQR) value from the conditional mean of individual estimates of Vd and CL was 68.4 (56.6-84.2) L and 0.86 (0.79-0.90) L/h, respectively. To ensure optimal vancomycin exposure during the first 48 h of therapy, the vancomycin loading dose of 1500, 1750, 2000, 2250, 2500 and 2750 mg should be administered to obese patients with a lean body mass of ˂50, 50-60, 60-70, 70-80, 80-85 and >85 kg, respectively.

• MeSH
• Anti-Bacterial Agents * pharmacokinetics   administration & dosage   MeSH
• Models, Biological MeSH
• Renal Dialysis * MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Monte Carlo Method MeSH
• Drug Monitoring MeSH
• Obesity * complications   MeSH
• Cross-Sectional Studies MeSH
• Retrospective Studies MeSH
• Aged MeSH
• Vancomycin * pharmacokinetics   administration & dosage   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

BACKGROUND: Since the incidence of vancomycin-resistant enterococci (VRE) is increasing and treatment options remain limited, we aimed to investigate the epidemiology of vancomycin- and tigecycline-resistant enterococci in a university hospital using whole genome sequencing (WGS). METHODS: Between April and December 2021, 102 VRE isolates were collected from a single tertiary care hospital in the Czech Republic. Forty selected isolates underwent antimicrobial susceptibility testing and WGS (Illumina short reads and long reads with MinION in selected isolates). RESULTS: All Enterococcus faecium isolates were resistant to ampicillin, carrying the PBP5_Met485Ala, PBP5_Glu629Val, and fluoroquinolones carrying the GyrA_Ser83Ile and ParC_Ser80Ile substitutions. The vanA operon was found on pELF2-like plasmids and plasmids carrying rep17 and/or rep18b genes. The novel Tn1546 structural variants were identified in vanA-carrying isolates. The vanB operon was located on the chromosome within a Tn1549 structural variant. Linezolid resistance was detected in one isolate carrying the 23S rDNA_G2576T substitution. Twenty-two isolates were resistant to tigecycline (tet(L), tet(M) and rpsJ_del 155-166 or RpsJ_Lys57Arg). Discrepancies between phenotypic and genotypic resistance profiles were observed for daptomycin (RpoB_Ser491Phe), trimethoprim/sulfamethoxazole (dfrG gene), nitrofurantoin (NmrA_Gln48Lys substitution without the EF0404 and EF0648 genes) and tetracycline (truncated TetM). The two multilocus sequence typing (MLST) schemes identified different numbers of STs: 5 STs, with ST117 as the predominant one (n = 32, 80%), versus 10 STs, with ST138 (27.5%), ST136 (25%), and ST1067 (20%) being the most frequent, respectively. The whole genome MLST revealed clonal clustering (0-7 allele differences) among isolates of the same ST. When comparing ST117 isolates from our study with 2,204 ST117 isolates from 15 countries, only one Czech isolate clustered closely with strains from Germany and the Netherlands, differing by just 16 alleles. CONCLUSIONS: The spread of E. faecium isolates ST117 resistant to vancomycin and tigecycline was identified. The discrepancies between resistance genotypes and phenotypes highlight the importance of combining molecular and phenotypic surveillance in antimicrobial resistance monitoring.

• MeSH
• Anti-Bacterial Agents * pharmacology   MeSH
• Bacterial Proteins genetics   MeSH
• Enterococcus faecium * genetics   drug effects   isolation & purification   classification   MeSH
• Vancomycin-Resistant Enterococci * genetics   drug effects   isolation & purification   MeSH
• Genome, Bacterial MeSH
• Gram-Positive Bacterial Infections * microbiology   epidemiology   MeSH
• Humans MeSH
• Microbial Sensitivity Tests MeSH
• Drug Resistance, Multiple, Bacterial genetics   MeSH
• Multilocus Sequence Typing MeSH
• Vancomycin Resistance genetics   MeSH
• Whole Genome Sequencing MeSH
• Tigecycline * pharmacology   MeSH
• Vancomycin * pharmacology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH

Public transport represents a potential site for the transmission of resistant pathogens due to the rapid movement of large numbers of people. This study aimed to investigate the bacterial contamination of frequently touched surfaces in the public transport system operating in the proximity of the biggest Czech hospital during the coronavirus pandemic despite extensive cleaning and disinfection efforts. In June and September 2020, samples from the metro trains, ground transport and stationary objects were collected, enriched and cultured. The antimicrobial susceptibility was tested by broth microdilution. Staphylococcus aureus isolates exhibiting inconclusive results of vancomycin susceptibility testing were retested by broth macrodilution and subjected to whole genome sequencing. All S. aureus isolates were tested for vancomycin heteroresistance (hVISA). A total of 513/542 (94.6 %) samples were culture-positive with higher frequency in September (p = 0.004). S. aureus was the most frequent opportunistic bacterial pathogen found (3.7 %, 20/542) followed by Enterobacterales spp. (1.8 %, 10/542). No methicillin-resistant S. aureus (MRSA), extended-spectrum beta-lactamase producers (ESBL) or carbapenemase-producing bacteria were detected. Resistance to clinically relevant drugs was rare except for resistance to ampicillin (67 %, 8/12), cefuroxime (42 %, 5/12) in Enterobacterales and chloramphenicol (90 %, 18/20), penicillin (45 %, 9/20), and erythromycin (20 %, 4/20) in S. aureus. One S. aureus isolate was shown to be resistant to vancomycin (8 mg/L) by forming large visible cell aggregates. Population analysis profile-area under the curve ratio (PAP-AUC) testing did not confirm the hVISA phenotype, but mutations in the hVISA phenotype-related gene vraR and other genes related to cell wall synthesis (fmtB) and intercellular adhesion (sasC) were found. Our study shows that in the COVID-19 pandemic, despite the intensive use of disinfectants, public transport was a source of opportunistic bacterial pathogens including S. aureus with unusual vancomycin resistance phenotype that could be easily missed by standard susceptibility testing.

• MeSH
• Anti-Bacterial Agents * pharmacology   MeSH
• COVID-19 * MeSH
• Transportation MeSH
• Humans MeSH
• Microbial Sensitivity Tests * MeSH
• Pandemics MeSH
• Vancomycin Resistance MeSH
• SARS-CoV-2 * MeSH
• Staphylococcus aureus * drug effects   genetics   MeSH
• Vancomycin * pharmacology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH

• MeSH
• Aminoglycosides administration & dosage   adverse effects   MeSH
• Anti-Bacterial Agents * administration & dosage   classification   adverse effects   MeSH
• Endocarditis * etiology   drug therapy   complications   physiopathology   MeSH
• Gram-Negative Bacteria pathogenicity   MeSH
• Humans MeSH
• Rifampin administration & dosage   MeSH
• Vancomycin administration & dosage   adverse effects   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Practice Guideline MeSH

Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa are major causes of hospital-acquired infections and sepsis. Due to increasing antibiotic resistance, new treatments are needed. Mesenchymal stem cells (MSCs) have antimicrobial effects, which can be enhanced by preconditioning with antibiotics. This study investigated using antibiotics to strengthen MSCs against MRSA and P. aeruginosa. MSCs were preconditioned with linezolid, vancomycin, meropenem, or cephalosporin. Optimal antibiotic concentrations were determined by assessing MSC survival. Antimicrobial effects were measured by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and antimicrobial peptide (AMP) gene expression. Optimal antibiotic concentrations for preconditioning MSCs without reducing viability were 1 μg/mL for linezolid, meropenem, and cephalosporin and 2 μg/mL for vancomycin. In MIC assays, MSCs preconditioned with linezolid, vancomycin, meropenem, or cephalosporin inhibited MRSA or P. aeruginosa growth at lower concentrations than non-preconditioned MSCs (p ≤ 0.001). In MBC assays, preconditioned MSCs showed enhanced bacterial clearance compared to non-preconditioned MSCs, especially when linezolid and vancomycin were used against MRSA (p ≤ 0.05). Preconditioned MSCs showed increased expression of genes encoding the antimicrobial peptide genes hepcidin and LL-37 compared to non-preconditioned MSCs. The highest hepcidin expression was seen with linezolid and vancomycin preconditioning (p ≤ 0.001). The highest LL-37 expression was with linezolid preconditioning (p ≤ 0.001). MSCs' preconditioning with linezolid, vancomycin, meropenem, or cephalosporin at optimal concentrations enhances their antimicrobial effects against MRSA and P. aeruginosa without compromising viability. This suggests preconditioned MSCs could be an effective adjuvant treatment for antibiotic-resistant infections. The mechanism may involve upregulation of AMP genes.

• MeSH
• Anti-Bacterial Agents pharmacology   therapeutic use   MeSH
• Antimicrobial Peptides MeSH
• Cephalosporins pharmacology   MeSH
• Hepcidins pharmacology   therapeutic use   MeSH
• Humans MeSH
• Linezolid pharmacology   therapeutic use   MeSH
• Meropenem pharmacology   therapeutic use   MeSH
• Methicillin-Resistant Staphylococcus aureus * MeSH
• Mesenchymal Stem Cells * MeSH
• Microbial Sensitivity Tests MeSH
• Pseudomonas aeruginosa genetics   MeSH
• Staphylococcal Infections * microbiology   MeSH
• Vancomycin MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

OBJECTIVES: To assess the effectiveness of shortened regimens of vancomycin or fidaxomicin in the treatment of Clostridioides difficile infection (CDI). METHODS: Adult patients with CDI hospitalized from January 2022 to May 2023 were included in this observational study. In patients with CDI treated with vancomycin or fidaxomicin, antibiotic treatment was discontinued after either 5 or 7 days of vancomycin or 5 days of fidaxomicin if there was a clinical response and improvement in laboratory parameters. The control cohort was treated with the standard 10 day regimen of either vancomycin or fidaxomicin. The follow-up was 60 days. Causative C. difficile strains were characterized by ribotyping and toxin gene detection when available. RESULTS: Twenty-five patients (median age 76 years) received shortened treatment with vancomycin (n = 21), or fidaxomicin (n = 4). Five cases fulfilled the criteria for severe CDI. Twenty-three patients completed follow-up; two died from causes other than CDI, and two developed recurrent CDI (8.0%). Ribotypes (RTs) 001 and 014 were the most prevalent with 20% each. In two C. difficile isolates, binary toxin genes were detected (RTs 078 and 023). In the control group of 22 patients recurrent CDI developed in 5 patients (22.7%). No statistically significant differences were found between the groups. CONCLUSIONS: Shortened treatment regimens for CDI with vancomycin and fidaxomicin were shown to be effective in our cohort of patients compared with 10 days of treatment. The recurrence rate was lower in the study group. A larger, prospective, double-blind, randomized, multicentre study is needed to support our findings.

• MeSH
• Anti-Bacterial Agents * therapeutic use   administration & dosage   MeSH
• Clostridioides difficile * genetics   drug effects   classification   MeSH
• Fidaxomicin * therapeutic use   administration & dosage   MeSH
• Clostridium Infections * drug therapy   microbiology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Ribotyping * MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Vancomycin * therapeutic use   administration & dosage   MeSH
• Treatment Outcome MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Observational Study MeSH

BACKGROUND: Systemically administered antibiotics are thought to penetrate the wounds more effectively during negative pressure wound therapy (NPWT).To test this hypothesis total and free antibiotic concentrations were quantified in serum and wound exudate. METHODS: UHPLC-MS/MS methods were developed and validated for the determination of ceftazidime, cefepime, cefotaxime, cefuroxime, cefazolin, meropenem, oxacillin, piperacillin with tazobactam, clindamycin, ciprofloxacin, sulfamethoxazole/trimethoprim (cotrimoxazole), gentamicin, vancomycin, and linezolid. The unbound antibiotic fraction was obtained by ultrafiltration using a Millipore Microcon-30kda Centrifugal Filter Unit. Analysis was performed on a 1.7-μm Acquity UPLC BEH C18 2.1 × 100-mm column with a gradient elution. RESULTS: The validation was performed for serum, exudates and free fractions. For all matrices, requirements were met regarding linearity, precision, accuracy, limit of quantitation, and matrix effect. The coefficient of variation was in the range of 1.2-13.6%.and the recovery 87.6-115.6%, respectively. Among the 29 applications of antibiotics thus far, including vancomycin, clindamycin, ciprofloxacin, oxacillin, cefepime, cefotaxime, cotrimoxazole, and gentamicin, total and free antibiotic concentrations in serum and exudate were correlated. CONCLUSION: This method can accurately quantify the total and free concentrations of 16 antibiotics. Comparison of concentration ratios between serum and exudates allows for monitoring individual antibiotics' penetration capacity in patients receiving NPWT.

• MeSH
• Anti-Bacterial Agents MeSH
• Cefepime MeSH
• Cefotaxime MeSH
• Chromatography, Liquid methods   MeSH
• Ciprofloxacin MeSH
• Exudates and Transudates MeSH
• Gentamicins MeSH
• Wound Infection * MeSH
• Clindamycin MeSH
• Trimethoprim, Sulfamethoxazole Drug Combination MeSH
• Humans MeSH
• Oxacillin MeSH
• Sternotomy MeSH
• Tandem Mass Spectrometry methods   MeSH
• Negative-Pressure Wound Therapy * MeSH
• Vancomycin MeSH
• Chromatography, High Pressure Liquid methods   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

In this paper, we describe a new method for synthesizing hybrid combinations of 1,2,3-triazoles with a tetracyclic quinobenzothiazinium system. The developed approach allowed for the production of a series of new azaphenothiazine derivatives with the 1,2,3-triazole system in different positions of the benzene ring. In practice, the methodology consists of the reaction of triazole aniline derivatives with thioquinanthrenediinium bis-chloride. The structure of the products was determined by 1H-NMR, 13C-NMR spectroscopy, and HR-MS spectrometry, respectively. Moreover, the spatial structure of the molecule and the arrangement of molecules in the crystal (unit cell) were determined by X-ray crystallography. The anticancer activity profiles of the synthesized compounds were tested in vitro against human cancer cells of the A549, SNB-19, and T47D lines and the normal NHDF cell line. Additional tests of antibacterial activity against methicillin-sensitive and methicillin-resistant staphylococci, vancomycin-sensitive and vancomycin-resistant enterococci, and two mycobacterial strains were also performed. In fact, the dependence of anticancer and antibacterial activity on the substituent type and its position in the quinobenzothiazinium system was observed. Furthermore, the distance-guided property evaluation was performed using principal component analysis (PCA) and hierarchical clustering analysis (HCA) on the pool of the calculated descriptors. Finally, the theoretically approximated partition coefficients (clogP) were (inter-)correlated with each other and cross-compared with the empirically specified logPTLC parameters.

• MeSH
• Anti-Bacterial Agents * pharmacology   MeSH
• Cell Line MeSH
• Chlorides MeSH
• Humans MeSH
• Cluster Analysis MeSH
• Vancomycin * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

PURPOSE OF THE STUDY Infections of joint replacements represent one of the most serious problems in contemporary orthopedics. The joint infections treatment is usually multimodal and involves various combinations of drug delivery and surgical procedures. The aim of this study was to evaluate and compare the bacteriostatic and bactericidal properties of the most common antibiotic carriers used in orthopedic surgery: bone cements mixed with antibiotic and porous calcium sulfate mixed with antibiotic. MATERIAL AND METHODS Three commercial bone cements (Palacos®, Palacos® R+G, Vancogenx®) and commercial porous sulfate (Stimulan®) were prepared with a known concentration of vancomycin (a glycopeptide antibiotic). Specifically, for the purpose of our study, the testing specimens were prepared to release 0, 1, 2, 4, 8, 16, 32, 64, 128, 256, and 512 mg of vancomycin into 1 liter of solution. The specimens with increasing amount of antibiotic were placed in a separate tubes containing 5 mL of Mueller-Hinton broth inoculated with a suspension (0.1 m, McFarland 1) of the reference strain CCM 4223 Staphylococcus aureus to evaluate their bacteriostatic properties (broth dilution method). After this initial incubation and evaluation of the broth dilution method, an inoculum from each tube was transferred onto blood agar plates. After another 24-hour incubation under the same conditions, we evaluated the bactericidal properties (agar plate method). As many as 132 of independent experiments were performed (4 specimens × 11 concentrations × 3 repetitions = 132). RESULTS The bacteriostatic properties of all investigated samples were excellent, perhaps with the exception of the first bone cement (Palacos®). The sample Palacos® started to exhibit bacteriostatic properties at concentrations ≥ 8 mg/mL, while all other samples (Palacos R+G®, Vancogenx®, and Stimulan®) were bacteriostatic in the whole concentration range starting from 1 mg/mL. The bacteriocidic properties did not show such clear trends, but correlated quite well with different properties of the investigated samples during mixing - the most homogeneous samples seemed to exhibit the best and the most reproducible results. DISCUSSION The reliable and reproducible comparison of ATB carriers is a difficult task. The situation is complicated by high numbers of local antibiotic carriers on the market, numerous antibiotics used, and differences in clinical trials at different laboratories. Simple in vitro testing of bacteriostatic and bacteriocidic properties represents a simple and efficient approach to the problem. CONCLUSIONS The study confirmed that the two most common commercial systems used in the orthopedic surgery (bone cements and porous calcium sulfate) prevent bacterial growth (bacteriostatic effect), but they may not be 100% efficient in complete elimination of bacteria (bacteriocidic effect). The scattered results in the case of bacteriocidic tests seemed to be connected with the homogeneity of ATB dispersion in the systems and with the lower reproducibility of the employed agar plate method. Key words: local release of antibiotics; bone cements; calcium sulfate; antimicrobial susceptibility.

• MeSH
• Agar MeSH
• Anti-Bacterial Agents pharmacology   therapeutic use   MeSH
• Bone Cements pharmacology   therapeutic use   MeSH
• Humans MeSH
• Orthopedic Procedures * MeSH
• Orthopedics * MeSH
• Polymethyl Methacrylate chemistry   MeSH
• Reproducibility of Results MeSH
• Calcium Sulfate MeSH
• Vancomycin pharmacology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH