Linezolid Research Articles

Assessing the Impact of Bedaquiline, Clofazimine, and Linezolid on Mycobacterial Genome Integrity

Tuberculosis (TB) presents significant medical challenges, largely due to the genetic diversity of Mycobacterium tuberculosis, which enhances the resilience and resistance of the pathogen to first-line treatments. In response to the global rise of drug-resistant TB, second-line antitubercular drugs like bedaquiline (BDQ), linezolid (LZD), and clofazimine (CFZ) have become critical treatment options. Understanding the molecular changes these drugs induce is essential for optimizing TB therapy. To contribute to this effort, we investigated their impact on genome maintenance and stability using Mycobacterium smegmatis as a model organism. Using mutation accumulation assays and whole-genome sequencing, we found that the second-line antibiotics did not significantly increase mutation rates, unlike the positive control UV treatment. However, upon BDQ treatment, we detected mutations in transporter proteins and transcription factors without any increase in the minimal inhibitory concentration. Additionally, BDQ and CFZ were found to alter DNA repair pathways and reduce cellular dNTP levels, particularly CFZ, which depleted dGTP, impacting DNA synthesis. CFZ also upregulated DNA repair enzymes, enhancing error-free repairs. Despite minimal mutagenic effects, both drugs displayed distinct impacts on cellular mechanisms, suggesting additional modes of action.

Formulation and Optimization of Solid Lipid Nanoparticle-based Gel for Dermal Delivery of Linezolid Using Taguchi Design.

Linezolid (LNZ) is a synthetic oxazolidinone antibiotic approved for the treatment of uncomplicated and complicated skin and soft tissue infections caused by gram-positive bacteria. Typically, LNZ is administered orally or intravenously in most cases. However, prolonged therapy is associated with various side effects and life threatening complications. Cutaneous application of LNZ will assist in reducing the dose, hence minimizing the unwanted side/adverse effects associated with oral administration. Dermal delivery provides an alternative route of administration, facilitating a local and sustained concentration of the antimicrobial at the site of infection. The current research work aimed to formulate solid lipid nanoparticles (SLNs) based gel for dermal delivery of LNZ in the management of uncomplicated skin and soft tissue infections to maximise its benefits and minimise the side effects. SLNs were prepared by high-shear homogenisation and ultrasound method using Dynasan 114 as solid lipid and Pluronic F-68 as surfactant. The effect of surfactant concentration, drug-to-lipid ratio, and sonication time was investigated on particle size, zeta potential, and entrapment efficiency using the Taguchi design. The main effect plot of means and signal-to-noise ratio were generated to determine the optimized formulation. The optimized batch was formulated into a gel, and ex-vivo permeation study, in-vitro and in-vivo antibacterial activity were conducted. The optimised process parameters to achieve results were 2% surfactant concentration, a drug-to-lipid ratio of 1:2, and 360 s of sonication time. The optimized batch was 206.3± 0.17nm in size with a surface charge of -24.4± 4.67mV and entrapment efficiency of 80.90 ± 0.45%. SLN-based gel demonstrated anomalous transport with an 85.43% in vitro drug release. The gel showed a 5 cm zone of inhibition while evaluated for in vitro antibacterial activity against Staphylococcus aureus. Ex-vivo skin permeation studies demonstrated 20.308% drug permeation and 54.96% cutaneous deposition. In-vivo results showed a significant reduction in colony-forming units in the group treated with LNZ SLN-based gel. Ex-vivo studies ascertain the presence of the drug at the desired site and improve therapy. In-vivo results demonstrated the ability of SLN-based gel to significantly reduce the number of bacteria in the stripped infection model. The utilization of SLN as an LNZ carrier holds significant promise in dermal delivery.

Hapten Synthesis, Antibody Generation, and Immunoassay Development for Linezolid Therapeutic Monitoring.

Linezolid (LNZ) is a broad-spectrum antibiotic used for the treatment of severe Gram+ infections. Significant pharmacokinetic variability in different groups of patients requires therapeutic drug monitoring (TDM) to ensure optimal therapy. This article presents the first description of the development of immunoanalytical TDM systems for LNZ. Four LNZ derivatives (H1-H4) with spacer arms of a different length (0-6.2-9.4-11.8 Å) and chemistry (aliphatic and heterocyclic) were synthesized to prepare H1-H3-immunogens and H1/H4-coating antigens or H1/H2-enzyme tracers. Three distinct antibody types against H1-H3 haptens were generated in rabbits and served as the basis for the development of ELISAs in heterologous coated antigen and coated antibody formats. The length of the spacer in the immunogen had an insignificant effect on the quality of the antibody generated or the performance of the designed coated antibody-ELISA formats (IC50 = 0.48-0.75 ng/mL) and coated antigen ELISAs (IC50 = 11.5-28.3 ng/mL). The coated antigen-based assays were considered more appropriate for monitoring therapeutic levels of LNZ due to their more convenient reduced sensitivity but wider dynamic range than the coated antibody-based assays (2.0-160 vs 0.16-2.1 ng/mL). The best recovery of LNZ (82.1-99.6%) from spiked human serum among the sample pretreatments examined was provided by the trichloroacetic acid deproteinization procedure. Serum samples derived from surgical patients with superimposed Gram-positive infections treated with LNZ were evaluated by parallel ELISAs using different immunoreagents. The results obtained in the various assays were found to be concordant, thereby confirming the reliability of the measurements and the developed assay systems suitable for TDM purposes.

Exploring the impact of baseline platelet count on linezolid-induced thrombocytopenia: a retrospective single-center observation study.

Patients treated with linezolid (LZD) frequently develop thrombocytopenia, and previous studies have identified the risk factors for this condition. However, the relationship between the development of LZD-induced thrombocytopenia and baseline platelet count has varied according to different reports. To explore the relationship between platelet count and the development of LZD-induced thrombocytopenia. Patients who underwent LZD at Hokkaido University Hospital in Japan from September 2008 to March 2023 were included. We collected data on patient characteristics and platelet counts at baseline and during LZD therapy from the electronic medical records. Thrombocytopenia was defined as a decrease in platelet count by 30% or more from baseline, or a platelet level < 100,000/µL. Two hundred and ninety-five patients who received LZD were included in this study, of whom 34.9% developed thrombocytopenia. In the early days of LZD treatment, the thrombocytopenia group showed a nearly 5% decrease in platelet count, while the non-thrombocytopenia group exhibited an increase of over 5%. Additionally, focusing on early onset thrombocytopenia (within 5 days), a baseline platelet count of < 150,000/µL was identified as a risk factor for early thrombocytopenia. Conversely, it was also observed that 24.7% of patients with a baseline platelet count ≥ 150,000/µL still developed early thrombocytopenia. Our findings suggest that while a baseline platelet count of < 150,000/µL is a risk factor for the early onset of thrombocytopenia, vigilant monitoring of platelet counts by clinical pharmacists in the early stages of LZD treatment is essential, regardless of baseline platelet levels.

A comparative evaluation of the antimicrobial efficacy of triple antibiotic paste, clindamycin, and linezolid as an intracanal medicament against Enterococcus faecalis: An in vitro study

ABSTRACT Aim: The aim of the present study was to evaluate and compare the antimicrobial efficacy of three medicaments, triple antibiotic paste (TAP), clindamycin (CLID), and linezolid (LZ) against Enterococcus faecalis, using spectrophotometry. Methods: Seventy-two single-rooted human premolars were collected and prepared using standard protocol and were decoronated to obtain standardized lengths. A pure culture of E. faecalis (ATCC 29212) was procured, grown on blood agar, obtained using a wired loop, and suspended in brain heart infusion (BHI) broth for 24 h. After contaminating the canals with E. faecalis, the prepared samples were divided into three groups, with 24 teeth each, based on the intracanal medicament used, Group A: TAP (ciplox×500 mg, metrogyl 400 mg, minoz 100 mg) + normal saline (NS), Group B: CLID (capsule clid 150) + NS, Group C: LZ (Lizoforce, dry syrup) + NS. The medicaments were syringed into the roots and which were then incubated. After 24 h, 12 samples per group were thoroughly rinsed for removal of intracanal medicaments (ICMs), and instrumented using #4 GG drill to obtain dentinal shavings, which were allowed to fall into sterile BHI broth. The turbidity of the broth was assessed and the optical density (OD) was recorded using spectrophotometer to estimate the concentration of E. faecalis after 1 day. After a period of 7 days, the remaining 12 samples per group underwent identical processing. Results: At the end of day 1, all three antibiotics presented comparable values of OD indicating comparable antimicrobial efficacy. Group-wise comparison revealed that TAP continued to be superior to the other two antibiotics even at the end of 7 days. However, the difference was significant only between TAP and LZ with no significant difference between TAP and CLID and between CLID and LZ. Conclusion: The present study concludes that the use of single-antibiotic CLID and LZ may serve as an effective alternative to the multidrug combination TAP, as an ICM.

Optimizing Dermal Delivery of Linezolid for Treating Skin and Soft Tissue Infections: NLC-Based Gel Formulation Using Taguchi Design

Background: Uncomplicated skin and soft tissue infections account for approximately 200 million visits to ambulatory care settings annually. Linezolid (LNZ) is an oxazolidinone that has proven its effectiveness in combating skin and soft tissue infections caused by gram-positive pathogens. LNZ is administered via oral suspension, tablets, or an intravenous route in most in-stances. However, its extended therapy leads to undesirable side effects like diarrhoea, thrombo-cytopenia, myelosuppression, lactic acidosis, etc. and even life-threatening complications. The dermal administration of LNZ offers an alternative route, ensuring localized and sustained release at the site of infection. This approach may reduce systemic exposure and allow for lower doses compared to oral ingestion, which can decrease the risk of adverse effects. Objective: This research aimed to develop a nanostructured lipid carrier (NLC)-based gel for de-livering LNZ via the dermal route to treat uncomplicated skin and soft tissue infections. Methods: NLC were developed by high-shear homogenisation and sonication method using glyc-eryl trimyristate as a solid lipid and neem oil as a liquid lipid. The Taguchi design was employed to optimize NLCs using surfactant concentration (mg), drug-to-lipid ratio, and sonication time (sec) as independent variables. Their effect on particle size, zeta potential, and entrapment effi-ciency was studied. The optimized nanocarriers were developed into a gel product and evaluated for drug release, permeation, and antibacterial activity. Results: The optimised process parameters to attain outcomes were 2% surfactant, 1:1 drug-to-lipid ratio and 300 seconds of sonication. The resulting NLC had an average size of 191.2 ± 2.76 nm, a zeta potential of -30.7 ± 4.50 mV, and 84.89 ± 2.76% drug entrapment. NLC-based gel dis-played anomalous transport with a 90.16 % drug release. The gel showed a strong antibacterial effect against Staphylococcus aureus with a 7.57 ± 0.12 cm mean zone of inhibition. Ex-vivo skin permeation studies revealed 24.19 ± 0.19 % drug permeation and 64.46 ± 0.58% cutaneous depo-sition. NLC-based gel demonstrated a significant decrease in colony-forming units in infected an-imal models. Conclusion: The ex-vivo investigations demonstrated the presence of LNZ at the infection site, enhancing therapeutic effectiveness. In vitro and in-vivo findings illustrated the substantial anti-bacterial efficacy of LNZ NLC-based gel. The adoption of NLC-based gel exhibits promising po-tential as a carrier for dermal delivery of LNZ.

Comparison of incidence of hyponatremia between linezolid and vancomycin in neonates and infants

A previous study reported that the incidence of hyponatremia after linezolid (LZD) use was higher than that with vancomycin (VCM) use in adults. However, hyponatremia due to LZD in neonates and infants was not investigated. This study aimed to compare the incidence of hyponatremia between LZD and VCM use in neonates and infants.The retrospective study was conducted at the Aichi Medical University Hospital. All patients who were cared for in NICU or GCU and received ≥3 days of LZD or VCM were included in this study. Hyponatremia was defined as serum sodium level ≤134 mEq/L and ≥5 % decrease from baseline after administration of LZD or VCM.A total of 76 patients (LZD, N = 36; VCM, N = 37) were included. There was no significant difference in the incidence of hyponatremia between the two groups (19.4 % vs 16.2 %, p = 0.72). The proportion of patients with a minimum value of serum sodium ≤134 mEq/L during treatment was 47.3 % in the LZD group and 35.1 % in the VCM group (p = 0.29), and the decrease in serum sodium level from baseline to the minimum value was 80.5 % and 78.4 %, respectively (p = 0.85).In conclusion, there was no significant difference in the incidence of hyponatremia between the LZD and VCM groups. Therefore, it is not necessary to avoid LZD use in neonates and infants because of the risk of hyponatremia.

Clinical drug interactions between linezolid and other antibiotics: For adverse drug event monitoring.

Detailed data on safety associated with drug-drug interactions (DDIs) between Linezolid (LZD) and other antibiotics are limited. The aim of this study was to investigate the safety signals related to these DDIs and to provide a reference for clinically related adverse drug event monitoring. Adverse event (AE) information from 1 January 2004 to 16 June 2022 of the target antibiotics including LZD using alone or in combination with LZD was extracted from the OpenVigil FDA data platform for safety signal analysis. The combined risk ratio model, reporting ratio method, Ω shrinkage measure model, and chi-square statistics model were used to analyze the safety signals related to DDIs. Meanwhile, we evaluated the correlation and the influence of sex and age between the drug(s) and the target AE detected. There were 18991 AEs related to LZD. There were 2293, 1726, 4449, 821, 2431, 1053, and 463 AE reports when LZD was combined with amikacin, voriconazole, meropenem, clarithromycin, levofloxacin, piperacillin-tazobactam, and azithromycin, respectively. Except for azithromycin, there were positive safety signals related to DDIs between LZD and these antibiotics. These DDIs might influence the incidence of 13, 16, 7, 7, 6, and 15 types of AEs, respectively, and is associated with higher reporting rates of AEs compared with use alone. Moreover, sex and age might influence the occurrence of AEs. We found that the combinations of LZD and other antibiotics are related to multiple AEs, such as hepatotoxicity, drug resistance and electrocardiogram QT prolonged, but further research is still required to investigate their underlying mechanisms. This study can provide a new reference for the safety monitoring of LZD combined with other antibiotics in clinical practice.

Exploring synergistic and antagonistic interactions in phage-antibiotic combinations against ESKAPE pathogens.

In the era of antimicrobial resistance, phage-antibiotic combinations offer a promising therapeutic option, yet research on their synergy and antagonism is limited. This study aims to assess these interactions, focusing on protein synthesis inhibitors and cell envelope-active agents against multidrug-resistant bacterial strains. We evaluated synergistic and antagonistic interactions in multidrug-resistant Staphylococcus aureus, Enterococcus faecium, and Pseudomonas aeruginosa strains. Phages were combined with protein synthesis inhibitors [linezolid (LZD), minocycline (MIN), gentamicin (GEN), and azithromycin (AZM)] or cell envelope-active agents [daptomycin (DAP), ceftaroline (CPT), and cefepime (FEP)]. Modified checkerboard minimum inhibitory concentration assays and 24-h time-kill analyses were conducted, alongside one-step growth curves to analyze phage growth kinetics. Statistical comparisons used one-way analysis of variance (ANOVA) and the Tukey test (P < 0.05). In the checkerboard and 24-h time-kill analyses (TKA) of S. aureus and E. faecium, phage-LZD and phage-MIN combinations were antagonistic (FIC > 4) while phage-DAP and phage-CPT were synergistic (FIC 0.5) (ANOVA range of mean differences 0.52-2.59 log10 CFU/mL; P < 0.001). For P. aeruginosa, phage-AZM was antagonistic (FIC > 4), phage-GEN was additive (FIC = 1), and phage-FEP was synergistic (ANOVA range of mean differences 1.04-1.95 log10 CFU/mL; P < 0.001). Phage growth kinetics were altered in the presence of LZD and MIN against S. aureus and in the presence of LZD against a single E. faecium strain (HOU503). Our findings indicate that select protein synthesis inhibitors may induce phage-antibiotic antagonism. However, this antagonism may not solely stem from changes in phage growth kinetics, warranting further investigation into the complex interplay among strains, phage attributes, and antibiotic mechanisms affecting bacterial inhibition.IMPORTANCEIn the face of escalating antimicrobial resistance, combining phages with antibiotics offers a promising avenue for treating infections unresponsive to traditional antibiotics. However, while studies have explored synergistic interactions, less attention has been given to potential antagonism and its impact on phage growth kinetics. This research evaluates the interplay between phages and antibiotics, revealing both synergistic and antagonistic patterns across various bacterial strains and shedding light on the complex dynamics that influence treatment efficacy. Understanding these interactions is crucial for optimizing combination therapies and advancing phage therapy as a viable solution for combating antimicrobial resistance.

Novel Approach to Photocatalytic Removal of Linezolid by Advanced Nano-Biochar/Bismuth Oxychloride Hybrid.

Herein, we introduce an innovative nanohybrid material for advanced wastewater treatment, composed of Corchorus olitorius-derived biochar and bismuth oxychloride (Biochar/Bi12O17Cl2), demonstrated in a solar photoreactor. This work focuses on the efficient degradation of linezolid (LIN), a persistent pharmaceutical pollutant, utilizing the unique (photo)catalytic capabilities of the nanohybrid. Compared with its individual components, the biochar/Bi12O17Cl2 hybrid exhibits a remarkable degradation efficiency of 82.6% for LIN, alongside significant chemical oxygen demand (COD) and total organic carbon (TOC) mineralization rates of 81.3 and 75.8%, respectively. These results were achieved within 3 h under solar irradiation, using an optimal composite dose of 125 mg/L at pH 4.3 ± 0.45, with an initial COD and LIN concentrations of 1605 and 160.8 mg/L and TOC of 594.3 mg/L. The nanohybrid's stability across five cycles of use demonstrates its potential for repeated applications, with degradation efficiencies of 82.6 and 77.9% in the first and fifth cycles, respectively. This indicates the biochar/Bi12O17Cl2 composite's suitability as a sustainable and cost-effective solution for the remediation of heavily contaminated waters. Further, the degradation pathway proposed the degradation of all of the generated intermediates to a single-ring compound. Contributing to the development of next-generation materials for environmental remediation, this research underscores the critical role of nanotechnology in enhancing water quality and ecosystem sustainability and addressing the global imperative for clean water access and environmental preservation.

Agreement between Phenotypically Detected Linezolid Resistance and Mutations in rrl and rplC Genes of Mycobacterium tuberculosis Isolates Using Nanopore Sequencing.

Phenotypic drug susceptibility testing (DST) is considered the gold standard for detecting linezolid (LZD) resistance in Mycobacterium tuberculosis (MTB), but it is time-consuming. Nanopore sequencing offers a potentially faster alternative approach. This study evaluated the agreement between phenotypically detected LZD resistance and mutations in the rrl and rplC genes of MTB isolates using nanopore sequencing. Consecutive drug-resistant MTB isolates from pulmonary samples collected in 2021 underwent liquid culture (LC) DST for LZD. All resistant isolates and an equal number of susceptible isolates were subjected to targeted sequencing of the rrl and rplC genes using nanopore technology. Sequencing identified a C154R mutation in the rplC gene in only one LZD-resistant isolate. No mutations were detected in the rrl gene. The agreement between sequencing and LC-DST for detecting LZD resistance was poor (Cohen's kappa: 0.03571, 95% confidence interval [CI]: -0.034-0.105). Additionally, no significant association was found between LZD resistance and clinical or microbiological outcomes at 6-month follow-up. This study revealed a considerable discrepancy between phenotypic and genotypic detection of LZD resistance in MTB. Further research is needed to better understand the genetic mechanisms underlying LZD resistance and to develop reliable molecular diagnostics for rapid resistance detection.

ER-mitochondria association negatively affects wound healing by regulating NLRP3 activation

Methicillin-resistant Staphylococcus aureus (MRSA) is the most common causative agent of acute bacterial skin and skin-structure infections (ABSSSI), one of the major challenges to the health system worldwide. Although the use of antibiotics as the first line of intervention for MRSA-infected wounds is recommended, important side effects could occur, including cytotoxicity or immune dysregulation, thus affecting the repair process. Here, we show that the oxazolidinone antibiotic linezolid (LZD) impairs wound healing by aberrantly increasing interleukin 1 β (IL-1β) production in keratinocytes. Mechanistically, LZD triggers a reactive oxygen species (ROS)-independent mitochondrial damage that culminates in increased tethering between the endoplasmic reticulum (ER) and mitochondria, which in turn activates the NLR family pyrin domain-containing 3 (NLRP3) inflammasome complex by promoting its assembly to the mitochondrial surface. Downregulation of ER-mitochondria contact formation is sufficient to inhibit the LZD-driven NLRP3 inflammasome activation and IL-1β production, restoring wound closure. These results identify the ER-mitochondria association as a key factor for NLRP3 activation and reveal a new mechanism in the regulation of the wound healing process that might be clinically relevant.

#1398 Linezolid adsorption during in vitro model of hemoadsorption with mini-module of HA380 cartridge

Abstract Background and Aims Septic shock is one of the most frequent causes in Intensive Care Unit (ICU) admission and is related to a very high risk of mortality. About one third of patients with sepsis develops acute kidney injury (AKI) which contributes to a worsening prognosis. AKI due to sepsis is the result of a dysregulated host immune response to infection, with the production of inflammatory mediators and cytokines that cause hemodynamic alterations, endothelial damage, apoptosis and, finally, immunoparalysis. The Jafron HA380 cartridge has been specifically designed for use in clinical conditions characterized by cytokine storm such as sepsis. Given the growing application of these hemoadsorption device in cases of septic AKI in ICU, an unsolved problem is whether these polymers adsorb drugs, including antibiotics. In vitro experiments were conducted to determine its adsorption capacity towards Linezolid (LZD) antibiotic. Method In vitro circulation was performed using a dedicated testing platform Galileo. A customized cartridge was built assembling mini-module components scaled in dimension towards HA380 and filled with 75 g of HA380 beads (25% of the regular size cartridge). Peristaltic pump was set at 250 mL/min. Four circulations were performed varying the initial mass of Linezolid in the tested solution (200, 400, 600, 1200 mg). Samples were collected after the first passage (FP) through the cartridge and every 5 or 10 minutes and Linezolid concentrations were measured. Adsorption was assessed considering the Removal Ratio (RR) and its kinetics. Results In vitro circulation confirms the affinity of beads material in binding Linezolid molecules. The kinetics shows an instantaneous and rapid adsorption in the very first part of the experiments. After that the adsorption rate decreases due to the decrease of antibiotic available in the solution. Among all the experiments, after the first passage of the solution through the cartridge, a RR higher than 70% has been achieved. After 100 passages of the solution into the cartridge, the adsorption reached about the 100% of RR. None of the amounts of Linezolid tested led to the cartridge saturation. A linear behavior between the mass injected in the solution and the mass adsorbed can be ascribable to the linear phase of Langmuir isotherm (see Fig.). Conclusion HA380 adsorbs significant amounts of Linezolid. The linear trend of the isotherm reveals a direct proportionality between binding sites of the sorbent material and the Linezolid tested. Further investigation using a higher quantity of Linezolid is necessary to reach the saturation of the cartridge and to understand the sorbent material capacity. These preliminary results highlight that there is an interaction that could affect the clinical outcome.

Facile fabrication of linezolid/strontium coated hydroxyapatite/graphene oxide nanocomposite for osteoporotic bone defect

Hydroxyapatite (HAp) coatings currently have limited therapeutic applications because they lack anti-infection, osteoinductivity, and poor mechanical characteristics. On the titanium substrate, electrochemical deposition (ECD) was used to construct the strontium (Sr)-featuring hydroxyapatite (HAp)/graphene oxides (GO)/linezolid (LZ) nanomaterial coated with antibacterial and drug delivery properties. The newly fabricated nanomaterials were confirmed by X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analysis and morphological features were examined by scanning electron microscope (SEM) analysis. The results reveal multiple nucleation sites for SrHAp/GO/LZ composite coatings due to oxygen-comprising moieties on the 2D surface of GO. It was shown to be favorable for osteoblast proliferation and differentiation. The elastic modulus and hardness of LZ nanocomposite with SrHAp/GO/LZ coatings were increased by 67 % and 121 %, respectively. An initial 5 h burst of LZ release from the SrHAp/GO/LZ coating was followed by 14 h of gradual release, owing to LZ's physical and chemical adsorption. The SrHAp/GO/LZ coating effectively inhibited both S. epidermidis and S. aureus, and the inhibition lasted for three days, as demonstrated by the inhibition zone and colony count assays. When MG-63 cells are coated with SrHAp/GO/LZ composite coating, their adhesion, proliferation, and differentiation greatly improve when coated with pure titanium. A novel surface engineering nanomaterial for treating and preventing osteoporotic bone defects, SrHAp/GO/LZ, was shown to have high mechanical characteristics, superior antibacterial abilities, and osteoinductivity.

Thrombocytopenia risks in ARDS COVID-19 patients treated with high-dose linezolid during vvECMO therapy: an observational study.

Patients treated with ECMO are at great risk of nosocomial infections, and around 10% of isolates are gram-positive pathogens. Linezolid (LZD) is effective in the treatment of these infections but appropriate dosing is challenging. The aim was to evaluate the occurrence of thrombocytopenia during ECMO when treated with LZD. An LZD trough concentration of 8mg/L was set as the cutoff value for thrombocytopenia occurrence among critically ill patients who received parenteral LZD therapy at a dose of 600mg every 8h during ECMO. Eleven patients were included in this prospective observational study. Median LZD trough concentrations were 7.85 (interquartile range (IQR), 1.95-11) mg/L. Thrombocytopenia was found in 81.8% of patients. Based on the median LZD trough concentrations cutoff value, patients were divided into two groups, 1.95 (IQR, 0.91-3.6) and 10.3 (IQR, 9.7-11.7) mg/L, respectively. Median platelet values differed significantly between groups on admission, ECMO day 0, ECMO day 1, and LZD sampling day [194 and 152.5, (p < 0.05)], [113 and 214, (p < 0.05)], [76 and 147.5, (p < 0.01)], and [26 and 96.5, (p < 0.01)], respectively. Duration of LZD therapy was similar between the groups. Significant platelet reduction was observed in both groups, emphasizing the need for closer monitoring to prevent LZD-associated thrombocytopenia.

An eco-friendly and cost-effective HPTLC method for quantification of COVID-19 antiviral drug and co-administered medications in spiked human plasma

The coronavirus-2 has led to a global pandemic of COVID-19 with an outbreak of severe acute respiratory syndrome leading to worldwide quarantine measures and a rise in death rates. The objective of this study is to propose a green, sensitive, and selective densitometric method to simultaneously quantify remdesivir (REM) in the presence of the co-administered drug linezolid (LNZ) and rivaroxaban (RIV) in spiked human plasma. TLC silica gel aluminum plates 60 F254 were used as the stationary phase, and the mobile phase was composed of dichloromethane (DCM): acetone (8.5:1.5, v/v) with densitometric detection at 254 nm. Well-resolved peaks have been observed with retardation factors (Rf) of 0.23, 0.53, and 0.72 for REM, LNZ, and RIV, respectively. A validation study was conducted according to ICH Q2 (R1) Guidelines. The method was rectilinear over the concentration ranges of 0.2–5.5 μg/band, 0.2–4.5 μg/band and 0.1–3.0 μg/band for REM, LNZ and RIV, respectively. The sensitivities of REM, LIN, and RIV were outstanding, with quantitation limits of 128.8, 50.5, and 55.8 ng/band, respectively. The approach has shown outstanding recoveries ranging from 98.3 to 101.2% when applied to pharmaceutical formulations and spiked human plasma. The method’s greenness was assessed using Analytical Eco-scale, GAPI, and AGREE metrics.

Linezolid Loaded Nanoparticle for Topical Administration of Diabetic Foot Treatment: Formulation, In Vitro and Ex Vivo Characterization

The aim of this research work was to develop a topical gel formulation containing nanoparticle to diabetic foot ulcer (DFU). In this respect, the nanoparticle formulations were prepared by using spontaneous emulsification technique. The linezolid (LZD) loaded nanoparticle formulation exhibited an low average particle size (PS) of 195.27±5.42 nm, low polydispersity index (PI) of 0.214±0.019, a high zeta potential (ZP) of 20.57±0.35 and high drug entrapment efficiency (EE) of 99.746±0.021%. In order to enhance topical residence time, the LZD-loaded nanoparticles were dispersed in a gel formulation using Methocel TM K4M (HPMC) and Carbopol® 974 P NF. The formulated gels demonstrated favorable characteristics, including an appropriate pH value, suitable mechanical performance, and desirable viscosity and spreadability for topical administration. All formulations displayed pseudoplastic flow and exhibited typical gel-type mechanical spectra at the specified frequency value. Moreover, the developed formulation achieved sustained drug release as intended for these systems. During the ex vivo drug diffusion studies, 0.007±0.004% of LZD was found in receptor phase, and this was an indicator of local effect. The optimum formulation was stable for 6 months. The initial findings suggest that the formulated topical gel containing LZD-loaded nanoparticles holds promise as an effective drug delivery system for DFU management. However, further comprehensive investigations are required to substantiate this hypothesis.

Synergistic interactions of essential oil components with antibiotics against multidrug-resistant Corynebacterium striatum.

In this study, it was aimed to examine the antibacterial activity of the essential oil components (EOCs), carvacrol (CAR), cinnamaldehyde (CIN), thymol (TH), alpha pinene (α-PN), eucalyptol (EU), limonene (LIM), and the antibiotics, linezolid (LZD), vancomycin (VAN), gentamicin (GEN), ciprofloxacin (CIP), clindamycin (CLN), and penicillin (PEN) against 50 multidrug resistant Corynebacterium striatum strains, and the synergistic interactions of CAR and CIN with the antibiotics against 10 randomly selected Coryne. striatum strains to explore synergistic interactions to determine if their combined use could enhance antibiotic activity and potentially reduce resistance. The activity of the EOCs and the antibiotics against Coryne. striatum strains isolated from clinical specimens, was examined by broth microdilution method. The synergistic interactions of the EOCs with the antibiotics against 10 randomly selected Coryne. striatum strains were determined by checkerboard method. EOCs, CIN, and CAR and antibiotics, LZD, VAN, GEN, CIP, and CLN were detected to have antibacterial activity against Coryne. striatum strains alone and either synergistic interactions were observed in combinations of the antibiotics with EOCs. All Coryne. striatum strains were determined to be susceptible to VAN and LZD and resistant to GEN, PEN, CIP, and CLN. Synergistic interactions were observed in all combinations of antibiotics tested with CAR and CIN.

A pragmatic randomized controlled trial to evaluate the efficacy and safety of an oral short-course regimen including bedaquiline for the treatment of patients with multidrug-resistant tuberculosis in China: study protocol for PROSPECT

IntroductionThe lack of safe, effective, and simple short-course regimens (SCRs) for multidrug-resistant/rifampicin-resistant tuberculosis (MDR/RR-TB) treatment has significantly impeded TB control efforts in China.MethodsThis phase 4, randomized, open-label, controlled, non-inferiority trial aims to assess the efficacy and safety of a 9-month all-oral SCR containing bedaquiline (BDQ) versus an all-oral SCR without BDQ for adult MDR-TB patients (18–65 years) in China. The trial design mainly mirrors that of the “Evaluation of a Standardized Treatment Regimen of Anti-Tuberculosis Drugs for Patients with MDR-TB” (STREAM) stage 2 study, while also incorporating programmatic data from South Africa and the 2019 consensus recommendations of Chinese MDR/RR-TB treatment experts. Experimental arm participants will receive a modified STREAM regimen C that replaces three group C drugs, ethambutol (EMB), pyrazinamide (PZA), and prothionamide (PTO), with two group B drugs, linezolid (LZD) and cycloserine (CS), while omitting high-dose isoniazid (INH) for confirmed INH-resistant cases. BDQ duration will be extended from 6 to 9 months for participants with Mycobacterium tuberculosis-positive sputum cultures at week 16. The control arm will receive a modified STREAM regimen B without high-dose INH and injectable kanamycin (KM) that incorporates experimental arm LZD and CS dosages, treatment durations, and administration methods. LZD (600 mg) will be given daily for ≥ 24 weeks as guided by observed benefits and harm. The primary outcome measures the proportion of participants with favorable treatment outcomes at treatment completion (week 40), while the same measurement taken at 48 weeks post-treatment completion is the secondary outcome. Assuming an α = 0.025 significance level (one-sided test), 80% power, 15% non-inferiority margin, and 10% lost to follow-up rate, each arm requires 106 participants (212 total) to demonstrate non-inferiority.DiscussionPROSPECT aims to assess the safety and efficacy of a BDQ-containing SCR MDR-TB treatment at seventeen sites across China, while also providing high-quality data to guide SCRs administration under the direction of the China National Tuberculosis Program for MDR-TB. Additionally, PROSPECT will explore the potential benefits of extending the administration of the 9-month BDQ-containing SCR for participants without sputum conversion by week 16.Trial registrationClinicalTrials.gov NCT05306223. Prospectively registered on 16 March 2022 at https://clinicaltrials.gov/ct2/show/NCT05306223?term=NCT05306223&draw=1&rank=1 {2}.

Poly(2-hydroxyethyl methacrylate)/BN nanohybride: Enhanced adsorption of antibiotic pollutant removal from wastewater

Increasing wastewater pollution by pharmaceutical waste poses a serious threat to environmental safety and public health, so sorbents with high adsorption capacity and removal efficiency are in high demand. To address this important problem, a novel pellet sorbent containing (2-hydroxyethylmethacrylate)-modified BN nanoparticles (pHEMA/BN) was produced by a combination of CVD synthesis (BN), solution method (pHEMA/BN nanoparticles) and uniaxial pressing (pHEMA/BN pellets) and studied for the adsorption of tetracycline (TC) and linezolid (LNZ) from aqueous solutions. Characterization techniques, including scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy, have provided insight into adsorbent microstructure and specific surface area. At an initial antibiotic concentration of 100 mg/L, pHEMA/BN adsorbent demonstrated an 84–88 % increase in equilibrium adsorption capacity after 24 h and an 86–89 % increase in antibiotic removal efficiency compared to unmodified BN. Molecular dynamics calculations revealed robust interactions between the polymer and BN, accompanied by an electron density redistribution. And density functional theory calculations showed the formation of multiple hydrogen bonds between the polymer hydroxyl groups and the antibiotic functional groups. Adsorption kinetics analysis suggested that pHEMA/BN adsorption involves both physical interaction and chemisorption. The pHEMA/BN material demonstrates good reusability with an adsorption efficiency >90 % after three sorption cycles with sorbent regeneration between cycles. These results highlight the high potential of pHEMA/BN adsorbents for practical applications in drinking water and wastewater treatment, offering versatility and efficiency in the pharmaceutical contaminant adsorption, thereby facilitating the development of more cost-effective and sustainable wastewater treatment methods compared to conventional adsorbents.