Clinical Microbiology and Infection

BackgroundOutbreaks of fluconazole-resistant Candida parapsilosis have recently emerged worldwide. In Spain, this phenomenon has been reported since 2020, mainly involving isolates from different clones harbouring the Y132F mutation at Erg11. MethodsWe analysed the expansion of fluconazole resistant C. parapsilosis strains within the national antifungal resistance surveillance program. Genetic clustering and relationships were assessed using microsatellite typing and whole genome sequencing. FindingsWe identified the expansion of three distinct clones carrying the Y132F mutation. Additionally, there was an increase in strains harbouring the G458S mutation, most of which belonged to a clonal complex, although other less prevalent clones were also detected. G458S isolates showed higher resistance to azoles than Y132F strains, particularly to voriconazole and isavuconazole. This increased resistance was associated with mutations in the Tac1 transcriptional regulator and duplication of a chromosomal region containing Tac1 and Erg11. One G458S isolate without mutation at Tac1 exhibited lower MIC values. Furthermore, two isolates carried the K143R mutation, and a distinct group of resistant strains without detectable ERG11 mutations was also identified. Resistant cases were detected across 31 hospitals in 12 autonomous regions. InterpretationOur findings indicate a concerning nationwide expansion of antifungal-resistant C. parapsilosis in Spain, involving multiple resistance mechanisms and clonal lineages, with implications for antifungal treatment and infection control strategies.

Background: Blood culture-negative infective endocarditis (BCNIE) poses a significant diagnostic challenge. This study evaluated a multimodal diagnostic algorithm combining serological and molecular methods at the Argentine National Reference Laboratory. Methods: A prospective analysis was conducted on 53 consecutive patients with suspected BCNIE referred between January 2019 and December 2024. The diagnostic workflow included indirect immunofluorescence for Bartonella spp. and Coxiella burnetii, species-specific PCR for Bartonella spp. and Tropheryma whipplei, and broad-range 16S rRNA PCR with Sanger sequencing on available blood and valvular tissue specimens. Results: An etiological diagnosis was established in 17 of 53 patients (32.1%). Bartonella spp. was the predominant pathogen (47.1%; 8/17), followed by T. whipplei (35.3%; 6/17) and Streptococcus spp. (17.6%; 3/17). All Bartonella cases were initially detected via serology, with molecular confirmation achieved exclusively through valvular tissue analysis. Conclusions: Implementing a standardized multimodal diagnostic algorithm significantly enhances etiological yields in BCNIE. The findings emphasize the complementary value of frontline serology and targeted molecular testing, highlighting that simultaneous submission of serum, blood, and valvular tissue is essential for optimal diagnosis.

Importance: Pharmacological targeting of host mechanisms that limit sepsis-induced organ dysfunction represents a new therapeutic approach. Preclinical studies showed that low-dose epirubicin enhances tissue damage control and attenuates sepsis severity independently of pathogen burden, thereby promoting disease tolerance to infection. Yet epirubicin can cause myelotoxicity when used in cancer therapy. Objective: To investigate whether low-dose epirubicin can safely be administered to patients with sepsis and septic shock. Design, Setting, and Participants: A randomized, double-blind, placebo-controlled clinical trial conducted in five German University hospitals. Patients with sepsis, defined by Sepsis-3 criteria, were eligible within 48 hours after diagnosis. The first patient was enrolled on October 19, 2022, and the last follow-up was conducted on May 21, 2025. Interventions: Eligible patients were randomized in a 4:1 ratio to receive either placebo or low-dose epirubicin in addition to standard care. There were three consecutive phases. Patients in the epirubicin group received a single dose of epirubicin (either 3.75 mg/m2, 7.5 mg/m2 or 15 mg/m2, depending on study phase). Main Outcomes and Measures: The primary endpoint of the trial was the 14-day myelotoxicity. Secondary and explorative outcomes included 90-day mortality, the degree of organ dysfunction as assessed by SOFA score, PK/PD modelling and cytokine release. Results: Of 854 patients assessed for eligibility, 32 were randomized and 31 were included in the primary analysis population. Six participants received placebo, nine participants received 3.75 mg/m2, nine received 7.5 mg/m2 and eight individuals received 15 mg/m2 epirubicin, respectively. There was no myelotoxicity in any group. Mortality at 90 days and SOFA-scores were not significantly different between groups. Two of 39 SAEs in the epirubicin group were assessed by the investigators as possibly related to epirubicin, Conclusions and Relevance Among patients with sepsis and septic shock, low dose epirubicin was not associated with increased myelotoxicity.

Importance: Immune checkpoint inhibitors (ICIs) produce diverse immune toxicities, but whether checkpoint blockade also modifies associations between other drugs and adverse events is poorly understood. Objective: To define ICI-associated toxicity organization and determine whether drug-associated adverse events and onset vary with ICI exposure and checkpoint pathway. Design and Setting: Cross-sectional analysis of deduplicated FAERS reports from 2016 through 2025; analyses performed in 2026. Participants: Among 13,701,106 deduplicated reports, 2,365,269 were cancer associated and 256,940 contained an ICI. Median age among cancer reports with observed age was 66 years (IQR, 56-75 years); 1,031,999 (43.6%) were female and 1,003,154 (42.4%) were male. Exposures: ICI exposure in any reported drug role, individual primary-suspect drugs, and checkpoint-pathway exposure. Main Outcomes and Measures: Reporting odds ratios (ORs), cross-organ adverse-event communities, adjusted primary-suspect drug x ICI interaction ORs for Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), acute generalized exanthematous pustulosis (AGEP), interstitial nephritis, drug-induced liver injury (DILI), and vomiting (VOM), and accelerated failure-time model time ratios for documented onset. Results: Of 3001 eligible Preferred Terms in cancer-associated reports, 2091 differed at a false discovery rate (FDR) less than .05. Four cross-organ toxicity communities were identified. Of 138 eligible drug-phenotype pairs, 65 had FDR-significant interactions, including moxifloxacin-SJS/TEN amplification (interaction OR, 101.72; 95% CI, 39.11-264.55), enfortumab vedotin-SJS/TEN attenuation (interaction OR, 0.17; 95% CI, 0.13-0.23), and omeprazole-interstitial nephritis amplification (interaction OR, 10.35; 95% CI, 7.62-14.05). Among 60,324 reports contributing to temporal analyses, ICI exposure was associated with longer adjusted documented time to onset for 5 of 6 phenotypes (time ratios, 1.37-1.59) but not AGEP (time ratio, 0.99; 95% CI, 0.67-1.46). Temporal associations also differed across checkpoint pathways. Conclusions and Relevance: ICIs were associated with a structured cross-organ toxicity landscape, phenotype-specific modification of drug-associated adverse events, and distinct temporal patterns across checkpoint pathways. These findings support checkpoint blockade as a modifier of drug-associated toxicity and motivate longitudinal and mechanistic validation.

Rationale. Guidelines disagree on antibacterial treatment for adults with community-acquired pneumonia and a positive respiratory viral test, particularly hospitalized patients and outpatients with comorbidities. Objectives. To estimate associations between antibacterial treatment selected for community-acquired pneumonia and outcomes in adults with virus-positive, imaging-evaluated nonsevere pneumonia. Methods. We conducted a retrospective multicenter study using Epic Cosmos data from 2016-2025. Hospitalized patients treated empirically by 24 hours were compared by continuation during hours 24-48; outpatients were compared by prescription at emergency-department discharge. Analyses were stratified by guideline-defined comorbidity and used propensity-score overlap weighting with source-cluster bootstrap confidence intervals. Exploratory analyses assessed respiratory virus, antiviral treatment, antibacterial class, and outpatient timing. Measurements and Main Results. The cohort included 376,320 adults: 275,604 inpatients and 100,716 outpatients. Inpatients who continued treatment had higher 30-day adverse-event risk without guideline comorbidity (adjusted risk difference, 1.70 percentage points; 95% confidence interval, 0.80-2.39) and with guideline comorbidity (2.56; 1.88-3.14), and longer post-landmark stay (adjusted mean ratios, 1.14 and 1.08). Exploratory class-specific analyses showed the largest adverse-event and mortality associations with broad therapy targeting resistant staphylococci or Pseudomonas; macrolide-containing and other atypical coverage showed no consistent adverse signal. Outpatient prescribing was associated with lower risks, but care-transition and residual confounding remained. Conclusions. Continued inpatient therapy after the empiric period showed no evidence of benefit and was associated with worse observed outcomes. Outpatient associations favored prescribing but remained vulnerable to care-transition and residual confounding.

Background: Refractory and macrolide-resistant Mycoplasma pneumoniae pneumonia (MPP) has emerged as a major challenge in pediatric respiratory medicine, amplified by the post-2023 resurgence. However, a systematic overview of the research landscape specific to treatment-refractory and drugresistant disease in children remains lacking. Methods: Research articles and reviews on pediatric refractory or macrolide-resistant MPP published between 2000 and 2025 were retrieved from OpenAlex using Boolean searches. After screening, 2,286 records were quantitatively analyzed for annual output, contributing countries/institutions, thematic clusters, and citation-burst dynamics using Python. Results: Annual publications grew exponentially, with a pronounced surge after 2023 (n=378 in 2025). China produced the highest volume (45.1%) but recorded fewer citations per publication than the US, Japan, and Canada. The literature resolved into four clusters: macrolide resistance/molecular basis, epidemiology, etiology/co-infection, and refractory disease management. Burst analysis showed an evolution from earlier fronts like 23S rRNA mutations and azithromycin to recent emerging trends like pandemic-related co-circulation, genotype surveillance, and co-infection. Conclusions: Research on pediatric refractory and resistant MPP is expanding rapidly, shifting in emphasis from etiologic descriptions toward resistance mechanisms and clinical management. Standardizing the treatment of macrolide-unresponsive disease and post-pandemic epidemiological surveillance represent the principal directions for future work. Keywords: Mycoplasma pneumoniae; children; macrolide resistance; refractory pneumonia; bibliometric analysis; research trends

Background: Drug-resistant tuberculosis (DR-TB) remains a major challenge to tuberculosis control in sub-Saharan Africa. Cameroon faces substantial challenges in managing DR-TB; however, national evidence on treatment outcomes remains unsynthesized. This systematic review and meta-analysis aimed to estimate pooled treatment outcomes, adverse drug events (ADEs), and predictors of unfavorable outcomes among patients with DR-TB in Cameroon. Methods: This systematic review and meta-analysis followed the PRISMA 2020 guidelines. PubMed, Scopus, Embase, Web of Science, the Cochrane Library, African Journals Online. Google Scholar and reference lists were also searched. Studies reporting World Health Organization-defined treatment outcomes among patients with DR-TB were included. Random-effects meta-analyses using generalized linear mixed models with logit transformation were performed. Heterogeneity was assessed using the I2 statistic, and publication bias and sensitivity analyses were conducted. Results: Fifteen studies conducted between 1998 and 2022 were included. The pooled mortality rate was 6.8% (95% CI: 4.7-9.7; 14 reports; n = 2,351 participants), loss to follow-up was 4.1% (95% CI: 2.8-6.1; 12 studies; n = 2,244 participants), and treatment failure was 5.0% (95% CI: 1.1-19.8; 12 studies; n = 2,050 participants). The pooled treatment success rate was 74.2% (95% CI: 60.4-84.4; 13 reports; n = 2,146 participants). Treatment success improved over time and was higher with modified regimens (87.2%; 95% CI: 83.8-89.9; 3 studies; n = 460 participants) than with standard regimens (68.8%; 95% CI: 52.2-81.6; 10 studies; n = 1,686 participants). Among patients with multidrug-resistant-TB, the pooled prevalence of adverse drug events was 70.8% (95% CI: 40.2-89.7; 3 studies; n = 251 participants), with ototoxicity (41.9%; 95% CI: 23.7-62.6; 3 studies; n = 251 participants) and gastrointestinal disorders (40.9%; 95% CI: 25.5-58.2; 2 studies; n = 172 participants) being the most common events. HIV co-infection was significantly associated with unfavorable treatment outcomes (pooled OR = 2.76; 95% CI: 1.95-3.93; 6 studies), and male gender was also associated with increased odds of unfavorable outcomes (OR = 1.73; 95% CI: 1.25-2.40; 5 studies). Conclusions: Approximately three-quarters of patients with DR-TB in Cameroon achieved successful treatment, although mortality, treatment failure, and adverse drug events remain important concerns. Strengthening pharmacovigilance, integrated TB/HIV care, and the implementation of effective all-oral regimens are essential to improve treatment outcomes. Systematic review registration number: CRD420261404490.

Background: Pooled testing increases testing efficiency and reduces testing costs. This approach has been recently recommended by the World Health Organization for use with low-complexity nucleic acid amplification TB diagnostics to increase access to testing when resources are constrained. Pooled testing can also be used with novel near point of care tests, and evidence is needed on diagnostic performance of pooled testing in these more portable, lower cost tests. Methods: We evaluated pooled testing on the Pluslife MiniDock MTB assay with stored sputum collected from adults with presumptive TB. We assessed sensitivity and specificity against the reference standard of liquid culture and diagnostic agreement against Xpert MTB/RIF Ultra and individual MiniDock MTB; we also estimated pooled testing efficiency. Results: Swabs from sputum specimens were tested in 287 pools of 3 and on 861 individual tests. Against culture, sensitivity of testing was 88% (87/99, 95%CI, 80-93%) as compared to 89% (88/99, 95%CI, 81-94%) for individual MiniDock MTB testing, with pooled testing specificity of 99% (97-99%) as compared to 95% (94-97%) for individual testing. Pooled testing saved 32% of tests in this population that included 12% (100) people with culture-positive TB. Conclusions: Pooled testing with sputum swabs from three people had similar diagnostic accuracy against TB culture as individual sputum swab testing in this evaluation. These results provide evidence that pooled testing with near point of care tests could help to further reduce testing costs and help to expand access to molecular testing at the lowest levels of the health system.

Background: Polymorphisms in the N-acetyltransferase 2 (NAT2) gene explain much of the interindividual variation in isoniazid (INH) metabolism and determine risk of toxicities. However, there is limited evidence to guide INH dose adjustment according to the NAT2 acetylator profile in weekly rifapentine-INH tuberculosis preventive therapy (TPT). Methods: In a prospective, multicenter, within-subject PK trial (NCT05413551), adults initiating 3HP in Brazil were assigned genotype-guided INH doses (slow: 5 mg/kg <=300 mg; intermediate: 15 mg/kg <=900 mg; rapid: 25 mg/kg <=1,500 mg) alongside a standard 900 mg flat dose on an alternate occasion. AUC0-24 and C24 were estimated from serial blood samples; a two-compartment Michaelis-Menten population PK model characterized NAT2 effects on clearance. Results: Among 228 participants, 47.4% (108/228) were intermediate, 43.4% (99/228) slow, and 9.2% (21/228) rapid acetylators. Genotype-guided dosing reduced AUC0-24 variability approximately two-fold versus standard dosing (CV 58.8% vs 76.8%) and increased exposure uniformity (median AUC0-24 27.2 [IQR 18.8-41.3] vs 43.2 [27.3-71.0] mg h/L). Among slow acetylators, C24 >0.15 ug/mL decreased from 27/42 (64%) with standard dosing to 1/42 (2%) with genotype-guided dosing (P<0.0001). In 104 participants with intensive PK sampling, rapid acetylators receiving guided doses had AUC0-24 similar to standard-dose intermediate acetylators (42.8 vs 39.5 mg h/L; P=.63). Monte Carlo simulations supported doses of 600, 900, and 1,200 mg for slow, intermediate, and rapid acetylators, respectively. Conclusions: NAT2-guided isoniazid dosing reduced variation in drug levels, averting very low and high AUC and C24. These findings inform genotype-stratified dosing of INH for TPT, which might reduce toxicities and improve outcomes.

ObjectiveCarbapenem-resistant Klebsiella pneumoniae harboring blaNDM poses a serious threat to public health; however, blaNDM-15 remains poorly characterized outside the dominant epidemic lineages. MethodsWe characterized K. pneumoniae strain ETFK6090, isolated from a perianal surveillance swab of an 11-month-old immunocompromised child in a paediatric intensive care unit. Investigations included antimicrobial susceptibility testing, broth conjugation, S1 nuclease PFGE with Southern blotting, complete genome sequencing, and comparative genomic analysis against 465 curated blaNDM-positive K. pneumoniae genomes from 37 countries. ResultsETFK6090 belonged to ST580 and exhibited resistance to carbapenems, ceftazidime-avibactam, broad-spectrum cephalosporins, fluoroquinolones, gentamicin, chloramphenicol and trimethoprim-sulfamethoxazole; amikacin and fosfomycin retained low MICs. The complete genome comprised one chromosome and five plasmids, blaNDM-15 was localized on a 46,161-bp IncX3 plasmid, confirmed by Southern blotting. Conjugation into Escherichia coli EC600 transferred carbapenem and cephalosporin resistance, confirming in vitro mobility. The blaNDM-15 genetic environment retained a conserved blaNDM module, with IS-mediated rearrangements at the downstream boundary. In the global comparison, blaNDM-1 and blaNDM-5 predominated, the ST580-blaNDM-15 combination was exceedingly rare, and ETFK6090 constituted a distinct branch apart from major epidemic lineages. ConclusionsA transferable IncX3-blaNDM-15 plasmid can emerge in an uncommon ST580 background, underscoring the necessity to extend genomic surveillance of carbapenem-resistant K. pneumoniae beyond dominant epidemic clones, particularly in high-risk paediatric and intensive-care settings.

Reduced cephalosporin resistance in Enterococcus faecium has traditionally been reported in laboratory mutants and, more recently, in a single clinical ampicillin-susceptible (AmpS) isolate. Herein, we investigated whether this phenotype is widespread by analysing 95 clinical enterococcal isolates (78 AmpS and 17 ampicillin resistant [AmpR]) collected from three hospitals in Spain and Portugal (2009-2025). Low ceftriaxone MICs ([&le;]4 mg/L) were detected in 19/51 (37.3%) AmpS E. faecium and 7/27 (25.9%) E. lactis but in none of the AmpR isolates. Low ceftriaxone MICs were associated with older patient age in both species and with prior ampicillin therapy in E. faecium, but not with other clinical or epidemiological variables. Ceftaroline MICs were consistently low among AmpS isolates, while ceftriaxone and cefotaxime showed greater variability. Low-MIC isolates were distributed across multiple clonal lineages and hospitals and did not share a distinctive resistance or virulence gene profile. PBP5 phylogeny and variation at the psr-pbp5 region separated AmpS from AmpR E. faecium but did not explain variability in ceftriaxone MICs. Five AmpS isolates with reduced ceftriaxone MICs carried chromosomal deletions that included the psr-pbp5 region and genes with diverse cellular functions. Variation in other candidate resistance genes (pbpA, ponA, pbpF, croRS, stpA/stk and murAA) did not consistently explain the MIC differences. These results reveal unexpected heterogeneity in intrinsic cephalosporin resistance in clinical E. faecium and E. lactis and suggest that additional genetic or regulatory mechanisms underlie reduced susceptibility.

Background Using a population-based cohort from the Calgary Health Zone (CHZ), Canada, we integrated longitudinal antimicrobial susceptibility and prescribing data with the whole genome sequences of five major pathogens. We aimed to assess how antimicrobial resistance (AMR) responds to prescribing changes and determine which bacterial strains shape these dynamics. Methods We analysed antibiotic prescribing rates, clinical and genomic data from 7,271 Staphylococcus aureus, 1,609 Enterococcus faecalis, 801 Enterococcus faecium, 11,363 Escherichia coli, and 2,319 Klebsiella pneumoniae isolates, associated with bacteraemia episodes in the CHZ between 2006-2022. Genomic clusters (referred to as strains) were identified using StrainGST and assigned to known sequence types (STs) or clonal complexes (CCs). Strain-level incidence, stratified by community-onset (isolates collected [&le;]48h after admission) and hospital-onset (>48h after admission), AMR phenotypes, and prescribing rates were modelled using negative-binomial and binomial regression. Temporal trends were quantified using average annual percentage change (AAPC). Findings Between 2010-2022, fluoroquinolone prescribing declined in both community (AAPC=-6.8% [95% CI -8.1, -5.4]; p<0.0001) and hospital settings (AAPC=-5.1% [-6.5, -3.7]; p<0.0001). This was accompanied by a significant reduction in fluoroquinolone resistance among Gram-positive species. Specifically, S aureus bacteraemia resistant to clinically important antibiotics, cloxacillin, ciprofloxacin, erythromycin, and clindamycin, declined from 2006 to 2022, mostly in hospital-onset cases (AAPC=-16.0%, [-19.3%, -12.7%], p<0.0001). In E coli, ceftriaxone and ciprofloxacin resistance were clustered in ST131 and the emerging ST1193; the latter increased steadily, particularly in community-onset cases (AAPC=17.7%, [0.0%, 30.0%], p<0.0001). CTX-M-27-producing E coli ST131 strains increased (AAPC=23.8%, [17.4%, 30.5%], p<0.0001) between 20082022, while CTX-M-14-producing E coli ST131 declined (AAPC=-15.9%, [-21.3%, -10.2%], p<0.0001) between 2013-2022. These trends were paralleled by an increase in community cephalosporin prescribing (AAPC=7.3%, [4.2%, 10.5%], p<0.0001) between 2010-2022. For K pneumoniae, hypervirulent ST23 was most common (N=88) with an increasing trend in incidence (AAPC=3.0%, [-2.8%, 9.2%]) between 2006-2019. Conclusions The contrasting resistance trends between Gram-positive and Gram-negative species underscore the complexity of AMR control efforts. Effective strategies will require stewardship efforts targeting multiple drug classes, genomic surveillance for emerging resistant strains, and interventions extending beyond hospital settings.

Introduction Miltefosine is the only approved oral antileishmanial agent, but its use in women of childbearing potential (WOCBP) is restricted due to preclinical teratogenicity. Current labeling recommends contraception during treatment and for at least five months thereafter, based solely on its long terminal elimination half-life. This study re-evaluated the required contraceptive duration using an exposure margin-based approach. Methods Virtual populations were generated from anthropometric data of 382 Indian, 4,462 Eastern African, and 4,019 Brazilian WOCBP with leishmaniasis. Published population pharmacokinetic models were used to simulate miltefosine exposure following 14-42-day regimens for visceral leishmaniasis (VL), post-kala-azar dermal leishmaniasis (PKDL), and cutaneous leishmaniasis (CL). A developmental safety exposure threshold was derived from the rat no-observed-adverse-effect level (0.6 mg/kg/day for 10 days) and adjusted using a 10-fold safety margin. Contraceptive durations resulting in median residual post-contraception exposure (AUCEOC-{infty}) below this threshold were considered supportive of contraceptive discontinuation. Results The developmental safety exposure threshold was estimated at 2.5 mg{middle dot}day/L. Despite pharmacokinetic differences across geographical regions and disease manifestations, required minimum contraceptive durations were consistent: three months from treatment initiation for the 14-day regimen, four months for 21- and 28-day regimens, and five months for the 42-day regimen. For the 14-day regimen, a single dose of a long-acting injectable contraceptive administered at treatment initiation would provide sufficient coverage. Conclusion An exposure margin-based approach supports shorter contraceptive durations than current recommendations. For the 14-day VL regimen, three months of contraception may provide a practical alternative to current labeling.

In primary healthcare centers lacking advanced imaging, community-based active tuberculosis (TB) case finding often relies on basic symptom screening. This approach often misses cases and leads to the inefficient allocation of rapid molecular testing (RMT). We aimed to develop and internally validate a simple clinical triage scorecard to improve TB detection and guide RMT use in resource-constrained settings. We conducted a retrospective cross-sectional study of 15,137 adults ([&ge;]18 years) evaluated within the Zero TB Yogyakarta program (2020-2025). Participants with complete clinical assessments and confirmatory GeneXpert results were included. Using multivariable logistic regression, we identified independent clinical predictors, which were subsequently transformed into an integer-based point scorecard. Model performance was evaluated via discrimination and calibration, utilizing bootstrap resampling (1,000 iterations) for internal validation. Among the 15,137 participants, 251 (1.7%) were GeneXpert-positive. The final multivariable model identified eight independent predictors: age, male sex, body mass index, prolonged cough, hemoptysis, unexplained weight loss, TB contact history, and diabetes mellitus. The model demonstrated strong predictive accuracy, with an optimism-adjusted AUROC of 0.836 and good calibration. When translated to the integer scorecard and compared directly to standard national symptom screening, the scorecard performed (AUROC 0.81 vs. 0.73; p<0.001). At a high sensitivity cut off score of [&ge;] 0, the tool achieved 93.63% sensitivity and 41.33% specificity. This point-of-care clinical scorecard provides higher diagnostic accuracy than standard symptom screening algorithms. By offering flexible operational thresholds, it empowers local health programs to dynamically balance the urgency of case detection with available diagnostic capacity, optimizing GeneXpert allocation where advanced radiological imaging is unavailable.

Objectives: To investigate whether ethambutol resistance in Mycobacterium avium complex is associated with the emergence of macrolide resistance. Methods: Patients who developed macrolide resistance during guideline-based treatment were included, and longitudinal analyses of minimum inhibitory concentrations and mutations in embB or the upstream region of embA were performed. Clinical, microbiological, and radiological characteristics were compared according to the mutation status of embB or embA upstream region, prior to the emergence of macrolide resistance. We further evaluated the impact of embB mutation on the development of macrolide resistance using in vitro time-kill assays. Results: Sixteen patients developed macrolide resistance during guideline-based treatment. None of these patients had an ethambutol minimum inhibitory concentration >=16 ug/mL or embB or embA upstream mutations at treatment initiation; however, 8/16 patients (50.0%) had an ethambutol minimum inhibitory concentration >=16 ug/mL at the time of macrolide resistance detection, and 7/16 (43.8%) had developed embB or embA upstream mutations prior to the emergence of macrolide resistance. Cavitary lesions were present in 1/7 (14.3%) patients with embB or embA upstream mutations. In strains with embB mutations, the minimum inhibitory concentration of ethambutol increased by 1-2 dilutions relative to that of pretreatment isolates, with a corresponding increase in the concentration required to suppress macrolide resistance. Conclusions: Ethambutol resistance may contribute to the development of macrolide resistance in patients with M. avium complex pulmonary disease, particularly in those without cavitary lesions.

Background: The condition of a patient with acute stroke often changes within hours of ICU admission. Prognostic work here targets fixed endpoints predicted from admission data, and trajectory phenotyping assigns one label per patient. We used longitudinal ICU data to identify interpretable dynamic clinical states, characterize transitions between them, and relate the current state to later events. Methods: Retrospective cohort study of 6368 adults with acute stroke in MIMIC IV v3.1. The first 72 h were divided into twelve 6-hour windows, and a hidden Markov model was fitted to 21 neurological, physiological and organ support variables. State number was chosen against criteria fixed before fitting: statistical fit, restart stability, state occupancy and clinical interpretability. Generalized estimating equations related the current state to new mechanical ventilation and vasopressor use within 12 h, and to ICU death within 72 h. Eleven sensitivity analyses assessed the robustness of the state solution. Results: Four states were selected: neurologically preserved-low support, neurological impairment low support, impairment renal dysfunction and impairment-respiratory support (63.3%, 7.8%, 11.8% and 17.1% of windows). Within 72 h, 40.3% of patients changed state at least once, and transitions ran in both directions rather than along a single severity gradient. States were identified without outcome data, yet ICU mortality by last state ranged from 2.9% to 43.9%. Adjusted for age, sex, subtype and Charlson index, the current state remained associated with organ-support escalation and death. State prevalence differed by at most 1.1 percentage points between training and test sets, and 10 of 11 sensitivity analyses gave a stable four-state solution (ARI 0.754 0.955). Conclusions: The early ICU course of acute stroke can be represented as movement among a small number of clinically interpretable states. The representation was reproducible in a held out set and across admission eras, but requires validation in an independent database before any clinical use.

BackgroundDespite the importance of oropharyngeal gonorrhoea in transmission, suboptimal antimicrobial responses and propensity for horizontal transfer of antimicrobial resistance at this site, it remains understudied. An oropharyngeal N. gonorrhoeae controlled human infection model (CHIM) represents a promising tool to study infection and undertake translational research. MethodsA panel of five contemporary N. gonorrhoeae isolates were subject to detailed characterisation to assess antimicrobial susceptibility, in vitro infectivity, cytotoxicity and serum sensitivity to inform challenge agent selection. A method for challenge agent manufacture, including release testing, was developed and validated. FindingsAll candidate isolates were able to infect the surface of pharyngeal and cervical cells in vitro. One isolate displayed an invasive phenotype, induced higher inflammatory cytokine production and displayed elevated serum resistance and was excluded. The remaining four isolates were minimally inflammatory, did not induce cytotoxicity and were susceptible to serum killing. Three of the four isolates grew in a defined liquid medium. Together these results led to the selection of a contemporary N. gonorrhoeae isolate suitable for use in CHIM. A challenge agent manufacture workflow was established and shown to reliably and reproducibly generate doses suitable for direct inoculation in an oropharyngeal CHIM. ConclusionPhenotypic characterization of candidate N. gonorrhoeae challenge agents led to the successful identification of a contemporary isolate suitable for implementation in a novel oropharyngeal gonorrhoea CHIM. We demonstrate the feasibility of a challenge inoculum manufacturing process that aligns with international best practice guidelines.

Leptospirosis is an infectious neglected zoonotic disease caused by pathogenic bacteria of the genus Leptospira. The genus comprises 43 pathogenic species, divided into two clades (P1 and P2), with the potential to cause disease on animals and humans. Despite the major impact of this disease on animal and human health, few quantitative real-time polymerase chain reaction (qPCR) assays have been validated to specifically detect all pathogenic Leptospira species, thwarting diagnosis and epidemiological studies. The gene encoding LipL32, the major leptospiral outer membrane protein, discriminates pathogenic P1 species from P2 and saprophytic. However, with the recent discovery of new species, the current lipL32-based qPCR assay cannot detect all classified P1 species. Furthermore, there are no currently validated molecular methods able to differentiate the presence of P1 and P2 species on clinical samples. Previous analyses have shown that the 23S ribosomal RNA gene displays considerable conservation in P1 and P2 species but sequence divergence in saprophytic species, a promising target for PCR-based detection and discrimination of those two clades. This study optimized and validated an improved lipL32- and 23S-based TaqMan qPCR assay using human and animal clinical samples. These newly optimized and developed assays resulted in a lower limit of detection and increased diagnostic sensitivity, resulting in the detection of all pathogenic species of the genus Leptospira currently described. These assays will improve the detection of leptospires from clinical and environmental samples, providing a valuable epidemiological and clinical tool to support One Health research on this important emerging disease.

Seasonal influenza remains a major cause of morbidity and mortality worldwide. Although neuraminidase inhibitors improve outcomes, influenza-related deaths persist. We evaluated the impact of early aspirin (ASA) and non-aspirin nonsteroidal anti-inflammatory drug (NSAID) use on outcomes in adults hospitalized with influenza. This retrospective study included adults admitted to the University of Minnesota Medical Center from 2016 to 2018. Continuous variables were summarized as medians with interquartile ranges (IQRs) and categorical variables as counts and percentages. Group comparisons used Wilcoxon rank-sum, Chi-square, or Fishers exact tests. Analyses included case-control comparisons, assessments by vaccination status, and subgroup analyses by early ASA or NSAID use. Among 2,816 patients, 320 had laboratory-confirmed influenza, with vaccination less common among cases. Unvaccinated patients had higher rates of intensive care unit (ICU) admission (23.6% vs. 11.1%; P = 0.003) and ventilatory support (15.0% vs. 6.1%; P = 0.009). In vaccinated patients, early ASA use was associated with older age and higher in-hospital mortality, whereas early NSAID use was associated with no in-hospital deaths, better one- and three-year survival (P < 0.001), and fewer, though not statistically significant, cardiovascular complications. In unvaccinated patients, ASA use was associated with lower three-year survival (59.1% vs. 79.2%; P = 0.013), while NSAID use was associated with fewer ICU admissions and no cardiovascular or renal complications. In both vaccinated and unvaccinated adults hospitalized with influenza, early NSAID use was associated with improved survival and fewer complications, whereas ASA use was associated with worse outcomes.

Background: Rituximab and ocrelizumab target the same CD20 receptor. Rituximab is off-patent and prescribed off-label; ocrelizumab is licensed and patent-protected. Whether the resulting differences in utilization and cost reflect clinical value or regulatory structure has not been examined. Objective: To determine whether utilization and cost of B-cell depleting therapy across six health systems track regulatory approval status more closely than comparative effectiveness. Methods: We examined rituximab and ocrelizumab utilization and cost in Sweden, France, Germany, the United Kingdom, Italy and the United States (2016-2024). Costs were drawn from published national sources on a consistent ex-factory basis. Utilization was registry-measured for Sweden, France and Germany, measured from national claims for the United States, and estimated from indirect data for the United Kingdom and Italy. Weighted annual costs per patient on B-cell depleting therapy were modeled by Monte Carlo simulation (10,000 iterations). Results: Rituximab constituted the near-totality of B-cell depleting therapy in Sweden but 2.3% to 18.7% of use in the other five systems. Mean annual cost per patient ranged from $3,014 (Sweden) to $52,506 (United States), a 17-fold difference, with the four other European systems between $18,140 and $26,262. Adopting Sweden's utilization pattern was associated with modeled five-year per-patient differences in drug acquisition cost of $76,000 to $248,000. Conclusion: Utilization and cost align more closely with regulatory approval status than with available effectiveness data. International reference pricing acts on the price of the licensed agent but leaves intact the regulatory asymmetry that determines which agent is prescribed.