International Journal of Antimicrobial Agents

Ganciclovir (GCV), and its orally available pro-drug valganciclovir (VGCV), are preferred therapies for treating congenital cytomegalovirus (cCMV), however, their use carries a significant risk of neutropenia for the child. This risk limits dosing and effectiveness of VGCV, particularly in the treatment of infants with cCMV infection, who are at increased risk for sensorineural hearing loss (SNHL). We hypothesized that an improved understanding of the pharmacokinetics (PK) and pharmacodynamics (PD) of VGCV in cCMV-infected infants at risk for SNHL would inform strategies for optimizing safe and effective VGCV dosing. Participants were enrolled in one of two clinical studies interrogating the PK, safety, and efficacy of VGCV treatment in cCMV-infected infants at risk for SNHL. GCV exhibited a short median half-life of 2.02 h and the median (range) area under the 24 h concentration-time curve (AUC24) was 60.8 (26.8, 99.4) g*h/mL. An AUC24 > 70 g*h/mL was associated with an elevated risk of neutropenia (Fisher's Exact p = 0.029). No associations between GCV PK and hearing outcomes were observed. Taken together, these results indicate vast inter-individual variability in GCV PK that is associated with dose-related toxicity, supporting the need for individualized dosing in the cCMV-infected population.

Biofilms pose a significant challenge to antimicrobial therapy. Bacteria in biofilms differ from planktonic counterpart in their altered metabolism, collective behavior, protective role of extracellular matrix and diversified microbial subpopulations. These attributions significantly influence bioavailability and activity of antibiotics. The presence of bacterial aggregates during acute infections expands the problem to many other conditions previously not discussed in the biofilm context. Klebsiella pneumoniae is a leading cause of life-threatening hospital-acquired infections and is included in the WHO Bacterial Priority Pathogens List due to increasing antimicrobial resistance. The combination of antimicrobial resistance and the ability to form biofilms severely limits the efficacy of antibiotic treatments. In this study, we investigated the in vitro susceptibility of mature biofilms to 13 antimicrobials of K. pneumoniae clinical isolates from a single hospital. The resistance profiles of the local clinical isolates were consistent with the global epidemiology of K. pneumoniae. Minimal biofilm eradication concentrations (MBEC) for mature biofilms were defined with two assays (biomass and metabolic activity measurements) and brought into relation with susceptibility breakpoints and plasma (Cmax). Colistin sulfate, tigecycline, cephalosporins and combination of imipenem with cilastatin were the most potent biomass eradicators, while suppression of metabolic activity was barely reachable. Moreover, we observed a notable increase in metabolic activity upon exposure to sub-MBEC concentrations of antibiotics. Finally, our data broach a subject of antibiotic prioritization with respect to biofilm tolerance. IMPORTANCEThis study addresses the critical gap between standard antibiotic susceptibility testing and the tolerance of biofilm and microbial aggregates during infections caused by K. pneumoniae. By systematically evaluating mature biofilms from a significant number of clinical isolates, we demonstrate that colistin and tigecycline show potent activity against both biofilm biomass and metabolic activity, whereas cephalosporins primarily reduce biomass without effectively suppressing bacterial metabolism, and other drugs have only weak effects on biofilms at clinically achievable concentrations. Furthermore, the alarming observation that sub-inhibitory biofilm eradication concentration (sub-MBEC) of antibiotic can paradoxically increase the metabolic activity of biofilms highlights a potential risk factor for therapy failure and resistance development. Our findings contribute to the necessary evidence base for prioritizing existing antibiotics in the limited armamentarium against biofilm-forming K. pneumoniae.

Rationale: Efficacious dose selection for anti-tuberculosis drugs has traditionally relied on achieving plasma exposures above the minimum inhibitory concentration, but this approach has not consistently aligned with clinical outcomes. Objectives: We sought to identify early pharmacokinetic-pharmacodynamic targets most predictive of clinical efficacious dose. Methods: We conducted a back-translational, pharmacokinetic-pharmacodynamic simulation-based analysis of 15 anti-tuberculosis drugs. Using pharmacokinetic data from multiple biological matrices and a range of pharmacodynamic metrics, we established candidate exposure-response targets for attainment. We systematically evaluated the predictive accuracy of each target pair against established clinical doses to formulate a decision-making framework linking key drug properties to the most predictive targets. Measurements and Main Results: Depending on the target used, projected clinical doses varied widely - both within and across compounds - highlighting the importance of target selection for dose projection and go/no-go decisions. In general, targeting cellular lesion-level drug exposures relative to in vivo preclinical potency provided an effective approach for early dose selection. However, for highly penetrating drugs, targeting site-of-action therapeutic exposures in the caseum was more predictive of clinical dose. Based on these findings, we developed a preliminary dose prediction tool that enables drug developers to estimate clinically relevant dose ranges of compounds using in vitro and early in vivo data. Conclusions: This work establishes and validates a simple, evidence-based framework to standardize early translational decision-making on dose selection of anti-tuberculosis candidates in development.

Background: Multi-drug resistant Bacterial (MDRB) Infections in the intensive care units (ICUs) substantially elevate patient mortality, prolong hospital stays, and impose heavy healthcare cost burdens. Existing predictive models for ICU-acquired MDRB infection predominantly focus on static admission-risk assessment, lacking the capacity to leverage longitudinal treatment data for dynamic risk re-stratification during the ICU stay. Meanwhile, most models suffer from poor clinical interpretability, overreliance on hard-to-collect biomarkers, or absence of deployable clinical tools, limiting real-world translation. Therefore, there is an urgent need to develop a parsimonious, interpretable tool based on routine cumulative data to guide timely intervention. This study aimed to develop a interpretable model with a web calculator to improve clinical applicability. Methods: In this study, we conducted a retrospective analysis of ICU inpatients at the First Affiliated Hospital of Dali University between January 1, 2023, and January 1, 2026. Using the create Data Partition function in R software (random seed = 42), the dataset was stratified and divided into a training group and a validation group in a 7:3 ratio. Feature selection was performed using the Boruta algorithm to validate variable rationality. A multivariable logistic regression model was constructed and visualized as a nomogram, and its performance was compared with six machine learning algorithms (Random Forest, XG Boost, Neural Network, etc.). Model validation was conducted using receiver operating characteristic curves (ROC), Decision Curve Analysis (DCA), and SHAP value interpretation. Finally, an online R Shiny calculator was developed based on the final model. Results: A total of 3,631 patients were enrolled and divided into a training group (n=2,543) and a validation group (n=1,088) using stratified random sampling. Five independent predictors were identified in the training group, which were hypertension combined with diabetes, antibiotic types, ventilator days, urinary catheter days, and PCT abnormality times. The Logistic regression model achieved an AUC of 0.772 (95%CI: 0.733-0.812) in the validation group, outperforming XG Boost (0.763) and Random Forest (0.703). The model demonstrated excellent calibration (Hosmer-Leme show {chi}{superscript 2} = 1.94, P = 0.9829) and positive net clinical benefit across threshold probabilities of 0%-40%. SHAP analysis aligned with regression-derived variable importance rankings, confirming predictor contributions. An open-access online calculator was successfully deployed (https://dongfangshao666.shinyapps.io/MDR_shiny2/), enabling real-time individualized risk stratification at the bedside. Conclusion: This study developed and validated a dynamic, interpretable multi-drug-resistant bacterial infection risk prediction model requiring only five routinely collected clinical indicators. The model balances robust predictive performance with high transparency, overcoming key limitations of prior tools. The accompanying web calculator supports dynamic risk reassessment throughout the ICU stay, facilitating precise antimicrobial stewardship, targeted infection control interventions, and optimized resource allocation, bridging the gap between statistical modeling and frontline clinical decision-making.

Antimicrobial resistance is an impactful One Health issue. One of its drivers is the extensive use of antibiotics in both human and animal production systems, and despite regulatory restrictions on antibiotic use in poultry farming, antimicrobial resistance remains a major challenge. Consequently, animals are at higher risk of harder-to-treat diseases and play a role as resistance reservoirs, highlighting the need for alternative antimicrobial strategies. Towards this end, antimicrobial peptides (AMPs) have emerged as promising candidates due to their broad-spectrum activity and lower propensity to induce resistance. However, the effectiveness of AMPs against poultry pathogens, and in particular multi drug-resistant strains, is largely unclear. To tackle this question, we evaluated the synthetic AMP SET-M33 against four species of clinically relevant pathogens in poultry, namely Escherichia coli, Salmonella enterica, Enterococcus faecalis and Enterococcus cecorum. Using a panel of 141 field isolates, we found that SET-M33 broadly inhibited bacterial growth at low micromolar concentrations (median MICs of 2.5 M and 5 M for Gram-negative and Gram-positive strains, respectively), including in multi drug-resistant isolates. To examine the potential impact of SET-M33 on the host, we established a new in vitro co-cultivation system using chicken intestinal organoids. We found that SET-M33 retains its antimicrobial activity in organoid-microbe co-cultures at concentrations that preserved host viability. These findings demonstrate the potential of SET-M33 as a new antimicrobial agent against pathogens in poultry.

Chronic kidney disease is a progressive condition characterized by the accumulation of nitrogenous waste products, including urea, creatinine, and uric acid, leading to significant morbidity in advanced stages. Current management strategies, such as dialysis, are effective but associated with substantial clinical and socioeconomic burdens, highlighting the need for alternative approaches to reduce circulating toxins. In this study, we evaluated a novel formulation of psyllium-based granules functionalized with specific antibody combinations targeting urea, creatinine, and uric acid. The aim was to assess the biochemical effects, as well as the binding and sequestration efficiency, of these formulations under controlled experimental conditions. A randomized, double blind controlled in vitro study was conducted using serum samples obtained from twenty patients with uremia undergoing dialysis. Three formulations, labeled S1, S2, and S3, were evaluated. All tested formulations resulted in statistically significant reductions in urea, creatinine, and uric acid concentrations compared with baseline values. Among them, the S1 formulation demonstrated the highest binding efficiency, reducing urea by 70% {+/-} 7%, creatinine by 80% about 4%, and uric acid by 52% about 11%. Linear regression analysis confirmed a statistically significant association between the S1 formulation and reductions in these biochemical parameters. These findings suggest that antibody functionalized granules can effectively bind and sequester nitrogenous waste products under in vitro conditions. This approach may represent a potential strategy for reducing uremic toxin burden, either as a complementary method or as a future alternative to existing renal replacement therapies. Further studies, including in vivo validation, dose optimization, and controlled clinical trials, are required to establish safety, efficacy, and translational applicability.

Klebsiella pneumoniae (Kp) is a common antibiotic-resistant pathogen that colonizes the gastrointestinal tract and can disseminate to peripheral sites, causing a range of infections including bacteremia, urinary tract infections, and pneumonia. Intestinal colonization with Kp is a risk factor for subsequent infection, as the colonizing strain frequently corresponds to the infecting isolate. Accordingly, targeting Kp prior to dissemination at the site of colonization through decolonization strategies offers a promising approach to mitigate infection risk. In this study, we evaluated the repurposing of existing drugs with previously uncharacterized antibacterial activity as candidates for Kp decolonization. To this end, we screened an antiviral compound library for their activity against Kp. We identified and validated six compounds with previously uncharacterized activity against Kp. Then, we screened a library of clinical Kp strains against a subset of these compounds and found that their activity was strain-specific to degrees that differed based on the compound. Finally, we tested the activity of these compounds in conditions relevant to the human gut. We determined the activity of these candidates was dependent on biological context. Collectively, these findings support further investigation of antiviral drugs as potential gut decolonization therapies for Kp.

The gut microbiome plays a central role in host metabolism, immune function, and overall health, with disruptions in microbial composition (dysbiosis) being associated with a range of metabolic, inflammatory, and infectious conditions [1,2]. Consequently, strategies aiming to modulate the microbiome require selective activity that preserves beneficial commensals while limiting pathogenic organisms [3]. In this context, ThymoQuin(R)--a cold-pressed, standardized black cumin (Nigella sativa) seed oil developed by TriNutra Ltd. and defined by [≥]3% thymoquinone (TQ), controlled p-cymene levels, and low free fatty acids ([≤]1.25%)--was evaluated for its microbiome-relevant activity. In vitro minimum bactericidal concentration (MBC) assays across three independent batches demonstrated a biphasic, dose-dependent response. At intermediate concentrations (0.25-0.5%), Streptococcus thermophilus was strongly stimulated (up to 53-fold) and Lactiplantibacillus plantarum fully preserved, while Klebsiella pneumoniae was effectively reduced (>94%). Akkermansia muciniphila exhibited stable viability at concentrations below 1%, with reductions only observed at 1%. This is notable given its role as a mucin-degrading commensal that has been linked to metabolic health, but whose abundance may vary across physiological and disease contexts [4,5]. At concentrations [≥]1%, selective effects diminished, resulting in broader antimicrobial activity and reduced specificity. These findings indicate a defined concentration range in which selective microbiome modulation is maintained, whereas higher thymoquinone levels may increase the risk of non-selective detrimental effect on microbes.

AimsPseudomonas aeruginosa biofilm-associated infections pose a significant clinical challenge due to their inherent antibiotic tolerance. This study aimed to evaluate the antibacterial and antibiofilm activity of Placentrex, a standardised aqueous placental extract, against P. aeruginosa and to elucidate its molecular mechanism of action using RNA sequencing (RNA-seq). Methods and ResultsPlacentrex exhibited potent bactericidal activity against P. aeruginosa at 50 mg/mL. Biofilm formation was significantly inhibited by [~]87% at 50mg/mL after 72 hours. Preformed biofilms were eradicated by [~]93% and [~]89% at 50 and 25 mg/mL, respectively. Interestingly, biofilm viability was reduced by [~]93% and [~]87% upon treatment with 50 mg/mL and 25 mg/mL of Placentrex, respectively. EPS characterisation revealed that the EPS contain a single large polysaccharide, and chromatography data suggested that it is made up of glucose as a monomer. RNA-seq identified coordinated downregulation of seven key genes, namely, flp major pilin (surface attachment), extracellular solute binding protein (ABC transporter-mediated nutrient sensing and biofilm maintenance), gntP permease (carbon metabolism), AraC family transcriptional regulator (quorum sensing and polysaccharide biosynthesis), ureE (urease nickel metallochaperone), aromatic amino acid permease (pyoverdine and PQS biosynthesis), and MFS transporter (efflux and autoinducer export). ConclusionsPlacentrex exerts comprehensive antibiofilm and antibacterial activity through simultaneous disruption of surface attachment, nutrient-sensing-driven biofilm maintenance, quorum sensing, carbon metabolism, urease virulence maturation, and efflux-mediated persistence. This polypharmacological mechanism supports Placentrex as a promising multi-target antibacterial agent against P. aeruginosa biofilm-associated infections. Impact statementPlacentrex is a potential anti-biofilm agent against Pseudomonas aeruginosa.

Purpose: Polypharmacy is highly prevalent among critically ill patients, yet it's independent impact on intensive care unit (ICU) outcomes in sepsis remains critically unexplored. We aimed to evaluate whether pre-admission polypharmacy independently predicts ICU mortality and provides incremental prognostic value using the medication reconciliation module of the MIMIC-IV-ED linked database. Materials and Methods: We conducted a retrospective cohort study of 3,347 adults admitted to the ICU who met Sepsis-3 criteria. Pre-admission polypharmacy was categorized as none (0-4), standard (5-9), or high (>=10 medications). Multivariable logistic regression, propensity score matching, and reclassification analyses (NRI/IDI) were performed. The primary outcome was in-hospital ICU mortality. Results: High polypharmacy was present in 58.9% of patients. Crude ICU mortality increased sequentially: 18.5% (none), 26.0% (standard), and 27.5% (high; p < 0.001). After multivariable adjustment, high polypharmacy independently predicted in-hospital ICU mortality (aOR 1.45, 95% CI (1.10-1.91)), and 28-day mortality (aOR 1.47). Drug-class analysis identified statins as significantly protective (aOR 0.56), whereas RAS blockers combined with diuretics increased acute kidney injury risk (aOR 1.49). Propensity matching confirmed the primary mortality association (matched aOR 1.28). Conclusions: By utilizing the ED medication reconciliation table, this study proves high polypharmacy represents a distinct 'pharmacologic frailty', independent of acute severity. Available instantly at triage, this zero-latency metric provides significant early prognostic value (SOFA NRI = 0.24) and identifies actionable high-risk interactions (e.g., RAS blockers plus diuretics) for immediate, targeted pharmacist-led intervention upon ICU admission.

BackgroundThe global rise of multidrug-resistant (MDR) bacteria represents a critical public health threat, and Romania ranks amongst the most affected countries in Europe. As conventional therapy increasingly fails, bacteriophage therapy has re-emerged as a promising alternative to antibiotics. Urban rivers, contaminated with resistant bacterial strains, represent an underexplored and accessible reservoir for the isolation of lytic phages with therapeutic potential. MethodsTwo bacteriophages, 17M_Ec17_D and 22C_Ec22_D, were isolated from the Dambovita River, Bucharest, Romania, using MDR E. coli as host bacteria. Phage characterization included plaque morphology, transmission electron microscopy, and host range assessment by spot assay against 30 MDR E. coli isolates. Whole genome sequencing was performed on Illumina MiSeq and Oxford Nanopore Technologies MinION platforms, followed by bioinformatic analysis including taxonomic classification, lifestyle prediction, and functional annotation. ResultsBoth phages formed clear plaques and were classified as Kayfunavirus (17M_Ec17_D, Podoviridae-like) and Kagunavirus (22C_Ec22_D, Siphoviridae-like) with nucleotide similarities of 89.2% and 71.4% to their closest relatives, respectively, suggesting both are candidates for novel species. Host range analysis revealed lytic activity against 13% and 10% of tested MDR isolates, with complementary infection profiles. Genomic analysis confirmed a strictly lytic lifestyle for both phages, supported by the presence of holin and spanin genes and the absence of lysogenic modules, antibiotic resistance genes, and virulence factors. ConclusionsTo the best of our knowledge, this is the first study conducted in Romania to isolate and genomically characterize lytic bacteriophages targeting MDR E. coli. The characterized phages represent safe therapeutic candidates whose complementary host ranges suggest potential application as part of phage cocktail to broaden antimicrobial coverage against MDR infections.

IntroductionErgosterol-targeting azoles are widely used in the treatment of Candida albicans infection. In addition to direct antifungal activity, azoles are known to enhance neutrophil-mediated killing of C. albicans, but the underlying mechanisms remain unclear, particularly whether ergosterol depletion directly modulates host immune responses. Gap StatementIt remains unknown whether reduced ergosterol levels alone, independent of broader disruption to sterol biosynthesis and fungal morphogenesis, influence neutrophil antifungal activity. AimThis study aimed to determine how genetic disruption of late-stage ergosterol biosynthesis affects neutrophil-mediated responses to C. albicans. MethodologyDoxycycline-repressible GRACE mutants targeting late-stage ergosterol biosynthesis genes (ERG4, ERG5, ERG3 and ERG28) were co-incubated with primary human neutrophils. Fungal survival, oxidative burst, phagocytosis, neutrophil extracellular trap (NET) formation and cell wall composition were assessed. ResultsAll ergosterol-deficient strains induced elevated neutrophil reactive oxygen species (ROS) production; however, only ERG4 depletion was associated with enhanced fungal clearance. This phenotype correlated with increased phagocytosis and reduced NET formation. Cell wall analysis revealed no changes in total chitin or mannan content but demonstrated significantly increased surface exposure of {beta}-1,3-glucan in ERG4-depleted cells. ConclusionThese findings indicate that disruption of late-stage ergosterol biosynthesis, particularly via ERG4, enhances neutrophil antifungal responses and is associated with increased {beta}-glucan exposure. This study highlights a potential role for ergosterol in immune evasion and suggests that targeting terminal steps of the pathway may improve host-mediated clearance of C. albicans.

Background: Antimicrobial resistance (AMR) is a global public health problem. Infections caused by extended-spectrum beta-lactamase (ESBL) and carbapenemase (CP) -producing Enterobacterales (E) threaten individuals and healthcare systems worldwide. Symptomatic infection caused by Enterobacterales is typically preceded by asymptomatic colonisation and often occurs in the most vulnerable individuals, thus interrupting asymptomatic transmission is desirable. The dominant transmission routes across the healthcare continuum including hospitals, intermediate care, and long-term care facilities are not well understood. Methods: Here we present a protocol describing a genomic surveillance framework developed for the Tracking Antimicrobial Resistance Across Care Settings (TRACS) Liverpool programme, which aims to identify critical ESBL-E transmission points in hospitals and care homes in Liverpool, UK. Our study integrates individual participant and healthcare facility data, validated standard operating procedures for taking and culturing stool, rectal, environmental, and staff samples, and genomic sequencing of ESBL-E, and statistical modelling approaches into a research framework for ESBL-E genomic surveillance. Discussion: There is a need for improved epidemiological and laboratory approaches to studying bacterial transmission. Drug-resistant enteric bacteria are a highly tractable marker of the movement of all enteric bacteria, and interventions designed to interrupt transmission of drug-resistant bacteria are expected to have a broader healthcare impact. This protocol provides a standardised, reproducible approach for identifying ESBL-E, tracking acquisition events, and linking clinical and environmental isolates through whole-genome sequencing.

Tuberculosis screening is not mandatory for prospective tissue donors. In 2021 and 2023, two different bone allograft products caused nationwide tuberculosis outbreaks. We assessed the morbidity and mortality of the second outbreak and reviewed donor and tissue screening to identify deficiencies. Thirty-six people residing in nine states received the product during spinal and dental procedures. Twenty-seven recipients had tuberculosis infection, 11 had microbiologic or imaging evidence of tuberculosis disease, and two died from tuberculosis within 12 months of outbreak detection. Another recipient died from tuberculosis nearly 3 years after product implantation. The bone donor died of pneumonia and septic shock. Polymerase chain reaction testing of the product before and after distribution did not detect Mycobacterium tuberculosis. Mycobacterial culture was not performed until after outbreak detection, when M. tuberculosis was isolated from 2 of 6 unused product units. This outbreak demonstrates persistent gaps in tissue transplant safety. Appropriate selection of donors and mycobacterial culture of donated tissues could reduce but not eliminate the risk of M. tuberculosis transmission. Therefore, it is important that clinicians monitor tissue recipients and promptly report adverse events to tissue establishments and health authorities.

The Burkholderia cepacia complex (BCC) is comprised of 24 species of Gram-negative bacteria that cause opportunistic infections. While antimicrobial susceptibility testing (AST) has historically been used to guide treatment for BCC infections, recent work highlighting problems with AST for these organisms led the Clinical and Laboratory Sciences Institute (CLSI) to remove disk diffusion (DD) and minimal inhibitory concentration (MIC) breakpoints for BCC from its M100 standards document. Epidemiological cut-off values (ECVs) may be helpful to clinicians in the absence of breakpoints, as they may be used to determine whether an isolate has a wild-type or non-wild-type phenotype. Here we present an analysis of BCC ECVs for ceftazidime (CAZ), levofloxacin (LVX), meropenem (MEM), minocycline (MIN), and trimethoprim-sulfamethoxazole (TMP-SMX). ECVs were calculated using MIC data from 3 previous studies and 3 independent laboratories for 1,896 BCC isolates. ECVs were 16 g/ml for CAZ, 8 g/ml for LVX, 16 g/ml for MEM, and 8 g/ml for MIN. The ECV for TMP-SMX varied depending on the analysis from 2 g/ml, 8 g/ml, and 16 g/ml and therefore could not be reliably established. Challenges with establishing ECVs for BCC include limitations with the pooled MIC dataset, broad MIC distributions, and high ECVs that are above the obsolete susceptible MIC breakpoints. These challenges limit the clinical utility of ECVs for these organisms and supported removal of ECVs from the CLSI M100 standards document. IMPORTANCEThe Burkholderia cepacia complex is a group of bacterial species that cause difficult-to-treat opportunistic infections. Recently, clinical breakpoints, which are used to determine whether organisms are susceptible to certain antimicrobials, were removed from Clinical and Laboratory Standards Institute (CLSI) standards for these organisms due to problems with antimicrobial susceptibility testing performance. Clinicians are now faced with the challenge of how to treat these complex infections without clinical breakpoints. Here we determine epidemiological cut-off values (ECVs) for relevant antimicrobials for the B. cepacia complex. While we established ECVs for four antimicrobials, we encountered significant challenges in our analyses, including limitations with data for these organisms and high ECVs that are not clinically useful. These challenges limit the practical use of these ECVs in helping guide clinicians on treatment and supported the eventual removal of ECVs from the CLSI M100 standards document.

Methicillin-resistant Staphylococcus (MRS) infections are a significant public health concern. Anterior nares serve as a major reservoir and source of spread of MRS ssp. People living with HIV (PLWHIV) tend to be at higher risk of colonisation with MRS organisms due to frequent healthcare exposure. We assessed the prevalence of MRS nasal carriage and associated factors among PLWHIV at the HIV clinic of Kiruddu National Referral Hospital, Kampala, Uganda, from May to July 2024. Nasal swabs from 256 PLWHIV were cultured, and microbiological isolation was performed at MBN Clinical Laboratories. Prevalence was calculated as proportions, and logistic regression identified associations with clinical and socio-demographic factors (p < 0.05). Of 256 participants, 163 (63.7%) carried Staphylococcus, with 82 (32%) identified as MRS carriers (8.9% MRSA, 23% MRCoNS). Frequent hospital visits ([&ge;]3) (adjusted incidence risk ratio [A-IRR] = 1.18 x 107, p < 0.001), second-line antiretroviral therapy (ART) (A-IRR = 3.82, p = 0.041), and unsuppressed viral load (>1000 copies/mL) (adjusted odds ratio [AOR] = 11.3, 95% CI: 2.11-60.58, p = 0.005) were significantly associated with MRS carriage. Mask-wearing was protective against MRCoNS (A-IRR = 1.66, 95% CI: 1.06-2.58, p = 0.026). MRS isolates exhibited high resistance to erythromycin (81.7%) and trimethoprim-sulfamethoxazole (79.3%), but susceptibility to linezolid (93.9%). MRS nasal carriage is prevalent among PLWHIV. Individuals with frequent health care contact and those on second-line ART regimens are more susceptible to MRS colonization, while individuals who wear face masks and those with an undetectable HIV viral load are less susceptible. Antimicrobial Resistance (AMR) surveillance within HIV programs, enhanced infection control, ART adherence, and targeted screening for high-risk groups are critical to mitigate colonization.

The poor prognosis of brain tumors, including IDH-wild-type glioblastoma (GB), as well as brain and leptomeningeal metastases, is partly related to the blood-brain barrier (BBB), which limits the delivery of hydrophilic anticancer drugs to the tumor site and surrounding brain parenchyma. Early studies using vital dyes demonstrated that intracranial injection could bypass the BBB in cats. We confirmed that, in guinea pigs, the vital dye Bleu Patente V diffused efficiently into the brain after a bolus intracranial injection, whereas the brain remained unstained after intravenous administration. Similarly, brain concentrations of the hydrophilic anticancer drug gemcitabine were significantly higher following intracranial injection than after intravenous administration. Consistent with these findings, Bleu Patente penetrated deeply into the cerebral cortex of sheep after a 24-hour intraventricular infusion. At the end of a 24-hour intraventricular infusion of 20 mg gemcitabine in sheep, mean gemcitabine concentrations reached 1,415 {micro}g/L in cerebrospinal fluid and 850 {micro}g/kg in brain tissue. These concentrations exceeded the IC90 values of gemcitabine for A172, U87-MG, and U118-MG human glioblastoma cell lines, as determined in vitro after 24 hours of incubation. We hypothesize that Bleu Patente dye and gemcitabine circumvent the blood-brain barrier (BBB) by utilizing the glymphatic system. Tolerance of a single 24-hour intraventricular infusion of gemcitabine at doses of 5, 10, and 20 mg was good. Taken together, these encouraging preclinical results support the resumption of Phase I clinical trials evaluating intraventricular infusion of gemcitabine in patients with refractory primary or secondary brain tumors.

Pseudomonas aeruginosa, a Gram-negative opportunistic pathogen is well known for life-threatening acute infections among the human population. The bacterium can withstand most antibiotics by using their high levels of inherent and acquired resistance mechanisms such as Biofilm-EPS, Persistence, and Quorum sensing (QS). Owing to the importance of adaptive antibiotic multi-drug resistance of P. aeruginosa, the current investigation is aimed to explore the phytochemicals derived from mangrove plants as potential agents to control biofilm and drug resistance mechanisms through a multi-mechanistic computational approach. For identifying potential compounds and target, In-silico drug repurposing technique is implemented by docking/virtual screening of 49 phytochemical compounds against 18 proteins involved in the Persister Cell formation, QS, and EPS synthesis in P. aeruginosa which resulted the proteins RelA and SpoT (persistence), PqsA, and PqSR (QS), and PelA and PelB (EPS synthesis) and compounds Taraxerone and Taraxerol to be potential. The results of docking were well corroborated with MD simulations. These targets and compounds explored through in-silico approach, are found to target potential antimicrobial pathways involving EPS synthesis, persistence genes, and QS, aiming to enhance antibiotic efficacy. Further, this study could be reference for in-vivo and in-vitro investigations to evaluate the further effectiveness of the compounds and potentiality of the proteins for MDR therapeutics of P. aeruginosa.

BackgroundThe gut-kidney axis plays a direct role in gastrointestinal and kidney health. Gut-derived metabolites like uremic toxins are associated with the pathophysiology of feline chronic kidney disease (CKD). The aim of the study was to identify novel fecal biomarkers and investigate the roles of gastrointestinal metabolites in feline CKD. ResultsFecal samples from 41 healthy non-CKD (control) and 67 CKD cats, including 5 IRIS stage 1 (CKD1), 37 stage 2a (CKD2a), 18 stage 2b (CKD2b), and 7 stage 3 (CKD3), were subject to fecal untargeted metabolomics and targeted short-chain fatty acid (SCFA) analyses. Multiple linear regression, adjusted for sex, age, body weight and study site, identified 64 differential metabolites between control and across CKD groups (P<0.0001 and FDR<0.10). Approximately 65% of the metabolites were lipids, including polyunsaturated long-chain fatty acids, acylcarnitines, and ceramides. Random Forest algorithm selected N1-methyl-2-pyridone-5-carboxamide (2PY), a uremic toxin from nicotinamide catabolism, as the top fecal marker for classifying feline CKD. Fecal 2PY was increased in CKD1 (P = 0.03), CKD2a, CKD2b, and CKD3 (all P<0.0001) compared to the controls. Data mining revealed serum concentration of 2PY was significantly increased with severity of CKD in cats, possibly due to impaired renal excretion. Cholesterol and arachidonic acid, markers for enterocyte shedding and inflammation, were increased in CKD3 versus control (both P<0.05). In healthy non-CKD cats, evident suggested fecal lipids increased with age (P<0.0001), and were higher in females versus males (P<0.0001). While fecal indole and p-cresol were increased in CKD3 versus control (both P<0.05), no change was observed in indoxyl sulfate (IS) or p-cresol sulfate (PCS). Fecal indole-3-acetic acid (IAA) was decreased in several CKD groups compared to the controls (all P<0.05). Finally, two branched SCFAs, isobutyrate and isovalerate, were increased in CKD3 versus control (both P<0.05). ConclusionsThe study revealed 2PY as a novel marker and unveiled profound alterations in intestinal lipid compositions with a potential link to gut barrier integrity and inflammation in CKD.

BackgroundRising antimicrobial resistance rates, require new therapeutic approaches such as antimicrobial peptides (AMPs), which are part of the innate immune defense, as alternatives to antibiotics. In this study, we aim to unravel the antibacterial activity of human histone H1.2 peptide against Pseudomonas aeruginosa and its potential immune modulatory role. MethodsWe used a hemofiltrate peptide database for antimicrobial peptide prediction to identify novel human AMPs. Thirteen sequences of histone H1 were identified as putative AMPs, synthesized, and tested against bacterial ESKAPE pathogens in a radial diffusion assay. SYTOX green assay, electrophoretic mobility shift assay, and differential proteomics assays were conducted to determine the mode of action of H1.2 peptide fragment. A crystal violet assay was performed to evaluate the inhibition of biofilm formation. The cytotoxicity of the peptide was tested in LDH and Alamar assays. Finally, to visualize the contributions of H1.2 in NETs formation, scanning electron microscopy was performed. ResultsThe H1.2 peptide inhibited the growth of P. aeruginosa in a dose and pH-dependent manner without cytotoxicity towards mammalian THP-1 cells. It acts on intracellular targets to inhibit the growth of P. aeruginosa. STRING analysis from the differential proteomics assay showed that H1.2 targets the downregulation of proteins involved in the biogenesis of outer membrane proteins, including the folding and trafficking of outer membrane proteins across the cytoplasmic membrane. Scanning electron microscopy images showed that H1.2 forms NET-like structures capable of trapping and immobilizing P. aeruginosa. ConclusionThe characterized antimicrobial activity of H1.2 points to a role for human histone H1 fragments in innate immunity and may represent a promising approach for the development of novel antibacterial therapies. Graphical Summary O_FIG O_LINKSMALLFIG WIDTH=192 HEIGHT=200 SRC="FIGDIR/small/724237v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@1778ddborg.highwire.dtl.DTLVardef@26430org.highwire.dtl.DTLVardef@ffbfa2org.highwire.dtl.DTLVardef@7e38ae_HPS_FORMAT_FIGEXP M_FIG C_FIG Sec transport and BAM complex system including chaperone proteins and quality control proteases are inhibited by H1.2 in Pseudomonas aeruginosa.Outer membrane proteins (OMPs) are synthesized in the cytoplasm and transported across the inner membrane via the Sec translocase, assisted by SecA/SecB or ribosomes. In the periplasm, they are escorted by chaperones such as SurA to the BAM complex for insertion into the outer membrane. Here, we show that H1.2, an antimicrobial peptide, targets membrane biogenesis in P. aeruginosa through downregulating Sec translocase (SecA/SecB and SecYEG), SurA, and BAM complex. Therefore, leading to improper transfer, folding and insertion of OMPs into the outer membrane. Normally, misfolded proteins are degraded by the protease MucD to prevent toxic aggregation in the bacteria. However, with H1.2 inhibiting MucD the proteotoxic stress is exacerbated, ultimately compromising bacterial homeostasis and viability. Figure created using BioRender.com.