Journal of Hospital Infection

BackgroundHand hygiene remains a cornerstone of infection prevention in surgical practice, particularly in orthopedic operating theatres where inadequate aseptic technique can increase the risk of surgical site infections and implant-related complications. Despite well-established recommendations from the World Health Organization (WHO) regarding proper surgical hand-scrubbing techniques, compliance in many healthcare settings remains inconsistent. Clinical audits provide a structured approach to evaluating adherence to such guidelines and implementing targeted improvements. This study aimed to assess baseline hand-scrubbing practices in an orthopedic operating theatre at a regional hospital in northern Pakistan and evaluate the impact of educational interventions on compliance with WHO standards. MethodsA prospective closed-loop clinical audit was conducted in the orthopedic operating theatre of Regional Headquarter Hospital Skardu, Pakistan, from December 1, 2025, to February 1, 2026. Approximately 40 healthcare personnel, including consultants, residents, nurses, and operating theatre assistants, participated in the audit. Baseline hand-scrubbing practices were observed during routine surgical sessions using a structured checklist based on WHO hand hygiene guidelines. Following the baseline assessment, educational interventions were introduced, including live demonstrations of correct hand-scrubbing techniques and placement of visual reminder posters in the scrub area. Post-intervention compliance was re-evaluated using the same checklist. Compliance rates before and after the intervention were compared using appropriate statistical analysis, with significance set at p < 0.05. ResultsBaseline observations revealed suboptimal compliance with recommended hand-scrubbing standards, particularly with regard to scrubbing duration, coverage of all hand surfaces, and proper drying technique. Following the educational intervention, significant improvements were observed across all evaluated components. Compliance with scrubbing duration of at least two minutes increased from 45% to 90%, coverage of all hand surfaces improved from 50% to 88%, proper antiseptic usage increased from 60% to 93%, and correct drying technique improved from 55% to 87%. Adherence to overall aseptic protocol also increased from 70% to 95%. All observed improvements were statistically significant (p < 0.001). ConclusionsThis prospective clinical audit demonstrates that structured educational interventions, including live demonstrations and visual reminders, can significantly improve compliance with recommended hand-scrubbing practices in orthopedic operating theatres. Regular audits combined with targeted educational strategies represent practical and cost-effective measures for improving infection control practices and enhancing patient safety in surgical settings.

The incidence of vancomycin-resistant Enterococcus (VRE) is rising in hospitals in Canada, and resistance to last-resort antimicrobials including linezolid complicates treatment options for multidrug-resistant isolates. Recent reports from around the globe indicate that both linezolid and vancomycin resistance genes can be co-carried and mobilized by linear plasmids (named pELF) in Enterococcus species, often on the same backbone. We aimed to investigate linezolid resistance and linear plasmid prevalence in VRE bloodstream infection isolates collected by the Canadian Nosocomial Infection Surveillance Program from 2009 to 2024. We found that screening for pELF linear plasmid ends in short reads was a reliable way to predict linear plasmid presence in large-scale surveillance data (100 % accuracy on 85 reference samples). Almost half of the isolates in our collection were predicted to carry pELF plasmids (45.4 %, 941/2071) and we found that this proportion has increased from 2018 (32.2 %, 59/183) to 72 % of isolates between 2021 and 2024 (2021: 68.5 % (115/168); 2022: 71.6 % (146/204); 2023: 72.8 % (166/228); 2024: 71.6 % (235/328)). This trend of increasing linear plasmid carriage is evident from 2018 to 2024 across the dominant emerging sequence types (ST80, ST17, ST117). Linezolid resistance based on phenotypic antimicrobial susceptibility testing was low (1.0 %, 21/2071). Using long read sequencing, we characterized the linezolid resistant isolates and confirmed pELF plasmid presence in 13/21 (61.9 %) isolates. Six isolates harboured pELF plasmids encoding linezolid resistance genes (optrA, cfr(D), poxtA) and five of these also encoded vancomycin resistance genes (vanA). We compared these six plasmids to 39 public plasmid sequences and clustered them using MOB-suite and pling. Overall, this study provides further examples of the co-carriage of vancomycin and linezolid resistance genes on mobile linear plasmids and shows that linear plasmid prevalence is detectable and increasing across VRE in Canada. IMPACT STATEMENTGiven the increasing prevalence of multidrug-resistant hospital-acquired pathogens, resistance to last-resort antibiotics is a global public health threat. Linezolid is a last-resort antibiotic used to treat vancomycin-resistant Enterococcus isolates, and the dissemination of linezolid resistance genes is significantly facilitated by mobile elements that can transfer between unrelated strains and species. Linezolid resistance genes have recently been described on linear plasmids and are often co-localized with other resistance genes on the same plasmid backbone. Consequently, understanding the features and distribution of linear plasmids and those harbouring linezolid resistance genes is crucial for pathogen surveillance and mitigation of resistance. In this work, we used long-read and short-read sequencing to characterize genomic epidemiology of linear plasmids across 16 years of Enterococcus surveillance data in Canada. This study furthers knowledge of linear plasmids by demonstrating that they are relatively common across vancomycin-resistant Enterococcus blood isolates and by providing more examples of co-localized vancomycin and linezolid resistance genes on the same linear plasmid backbone. DATA SUMMARYSequencing data and genome sequences were deposited in National Centre for Biotechnology BioProject PRJNA1279082, and accessions are listed in Table S1. Supplementary materials for this study are available at the Figshare portal through DOI: XXX.

BackgroundPseudomonas aeruginosa is a major cause of healthcare-associated infections in paediatric settings, where its persistence in moist environments such as hospital water and wastewater systems poses a particular risk to neonates and immunocompromised children. AimThe aim of this study was to showcase the long-term survival and transmission of P. aeruginosa in a large tertiary childrens hospital in England which is crucial to develop strategies for water-safe care. MethodsEnvironmental P. aeruginosa isolates were collected from taps, sinks, showers, and baths in augmented care areas of a 330-bed tertiary childrens hospital built to NHS water-safety standards. Clinical isolates were classified as invasive (blood, cerebrospinal fluid, and bronchoalveolar lavage) or non-invasive (respiratory, urine, ear, abdominal, and rectal surveillance). Variable number tandem repeat (VNTR) profiles and metadata were extracted from PDF reports, de-identified, deduplicated, and curated using Python and R. FindingsThis retrospective study analysed nine-locus VNTR profiles of 457 P. aeruginosa isolates submitted to the UK Health Security Agency from a large tertiary childrens hospital, identifying 56 isolate clusters (each with [&ge;]2 isolates), of which 19 (34%) contained at least one invasive isolate. The most persistent cluster (Cluster 1, n=20) spanned from July 2016 to September 2024, containing environmental and clinical (invasive and non-invasive) isolates. ConclusionThese findings demonstrate long-term persistence of certain genotypes and temporal overlap between environmental and clinical isolates, highlighting the difficulty in detecting and eradicating P. aeruginosa in hospital water and wastewater systems and reinforcing the need for continuous rigorous water system controls.

BACKGROUNDAutomated antimicrobial susceptibility testing (AST) systems are crucial for accurate, timely detection of drug-resistant microbial isolates. This meta-analysis assessed the performance of the BD Phoenix ("Phoenix", BD Diagnostic Solutions), Vitek(R) 2 ("Vitek 2", bioMerieux), and DxM MicroScan WalkAway ("MicroScan", Beckman Coulter, Inc.) AST systems relative to common reference methodology. METHODSA systematic literature search in Ovid (MEDLINE and Embase) yielded 275 unique (not duplicated) records, with 44 additional records retrieved from handsearching; 39 studies met inclusion criteria. Categorical agreement (CA), essential agreement (EA), very major errors (VMEs), and major errors (MEs) for the three instruments were compared to a common reference method. Ratios of proportions were analyzed using random-effect meta-regression. RESULTSThe instruments did not differ significantly in CA, EA, or ME. Vitek 2 showed a higher overall VME rate than Phoenix ([~]44% higher; Vitek 2-to-Phoenix ratio = 1.44; p=0.062 [approaching significance]) and MicroScan (74% higher; ratio = 1.74; p=0.045). No appreciable difference was observed for VME between Phoenix and MicroScan. Subgroup analyses should be interpreted cautiously due to limited overall significance indicating varying performance across systems. Vitek 2 generally had higher relative VMEs for gram-negative organisms and lower relative VMEs for gram-positive organisms, whereas Phoenix showed the opposite pattern. MicroScan had relatively low VMEs when stratified by Clinical and Laboratory Standards Institute (CLSI) criteria; no differences in VMEs were observed using European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. CONCLUSIONAlthough some VME differences were noted, overall performance of the three systems was comparable. Organism- and drug-specific VME patterns--and updates to CLSI criteria over time--highlight the importance of continued monitoring of current breakpoints for all three instruments.

BackgroundUnited Kingdom Standards for Microbiology Investigations limits the pre-analytical delay of blood cultures to a maximum of four-hours between collection and incubation. Compliance with this delay standard is a measure of the ability of a microbiology service to support the management of sepsis which is a life-threatening complication of infection. A positive blood culture confirms the infection and an early result is critical to the effective management of the condition. Delayed results lead to the prolongation of empiric broad spectrum antimicrobial therapy which is considered a causal factor in the emergence of antimicrobial resistance. This retrospective observational study documents compliance with the standard by microbiology services in England in 2022/23. The impact of laboratory centralisation on the ability of microbiology services to comply with this standard is examined. MethodsFreedom of Information requests were submitted to 116 National Health Service Trusts/administrative units in England requesting retrospective audit data showing compliance with the recommended pre-analytical delay standard. Data relating to service configuration and cost were also requested. ResultsResponses were received from 89 Trusts (76.7%) managing 146 hospitals. Overall, the rate of compliance was low, with only four hospitals (2.7%) showing full compliance and 31.5% showing >80% compliance. ConclusionsPoor rates of compliance with the PAD standard are a concern as prompt attention to blood cultures improves patient outcomes from sepsis and supports antimicrobial stewardship. Laboratory centralisation has resulted in withdrawal of staff and facilities from some hospitals with insufficient investment in others, leading to a demonstrable inability of many hospitals to comply with this standard. Compliance will require investment in microbiology services. The financial implications of the improvements proposed should be evaluated in the context of overall health care and community benefits.

Bubble continuous positive airway pressure (bCPAP) is a low-cost respiratory support device that has demonstrated different outcomes for children with severe pneumonia in different settings. Some differences in outcomes may be attributable to implementation factors (e.g., patient monitoring and feeding practices). We aimed to characterize bCPAP reach, implementation fidelity, and safety outcomes for children with severe pneumonia in Pakistan. We conducted a prospective cohort study at Aga Khan University Hospital and Abbasi Shaheed Hospital from February through May 2025. We enrolled children 1-59 months who met WHO criteria for severe pneumonia within 24 hours of presentation to the emergency department. Participants were followed daily via chart review, caregiver survey, and physical exam through discharge, transfer, or death. We reported the proportion of children receiving bCPAP ("reach") and constructed a mixed-effects, multinomial logistic regression model with robust standard errors to report: fidelity (child location in a highly monitored area, continuous monitoring, avoidance of unplanned disruptions to bCPAP, and avoidance of oral feeding); safety (aspiration events and pneumothorax); bCPAP failure (death, respiratory support escalation, or leaving against medical advice); and in-hospital mortality. Of 165 children with severe pneumonia, 88 (53%) received bCPAP over 141 bCPAP days. The average predicted probabilities (95% CI) of our fidelity measures were: 85% (78-92%) for location in a highly monitored area; 56% (51-60%) for continuous monitoring; 66% (57-75%) for continuous bCPAP without disruptions; 46% (36-55%) for avoidance of oral feeding while on bCPAP. Among children receiving bCPAP, 9 (10%) experienced an aspiration event, 1 (2.2%) experienced a pneumothorax; 19 (22%) experienced bCPAP treatment failure. One child (1.1%) died; 6 (6.8%) required respiratory support escalation; 14 (16%) left against medical advice. We identified several gaps in bCPAP reach and fidelity. These may be modifiable by individual-and team-targeted strategies to reduce bCPAP-related complications and pneumonia-related child deaths.

Background The COVID-19 pandemic has caused significant global mortality. Despite declining infection rates, new variants of SARS-CoV-2 continue to emerge, necessitating new prevention strategies. Objective This study aimed to evaluate the effect of four over-the-counter (OTC) antiseptic mouthwash/gargling solutions in the U.S., compared with a distilled water control, on SARS-CoV-2 viral load across multiple oral and oropharyngeal sample types. Methods This pilot single-center randomized controlled clinical trial enrolled adults in the San Francisco Bay Area, California, who tested positive for COVID-19. Participants were randomized to distilled water, chlorine dioxide, hydrogen peroxide, cetylpyridinium chloride, and essential oils. Participants were instructed to rinse and gargle four times daily for four weeks using standardized instructions to ensure protocol adherence. Samples were collected on Days 1, 7, and 28 and analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The primary outcome was the change in SARS-CoV-2 viral load from baseline to Day 28, assessed using cycle threshold (Ct) values. Secondary outcomes included self-reported clinical symptoms and hospitalization. Results Forty-nine participants completed the study. No mouthwash demonstrated a statistically significant reduction in SARS-CoV-2 viral load over time. Cetylpyridinium chloride showed a transient increase in Ct values on Day 7 that was not sustained on Day 28. At baseline, throat swab samples had the lowest Ct values across all sample types. Due to limited subgroup sample sizes for secondary outcome measures, no statistical or moderator analyses were conducted. Conclusion Further large-scale randomized trials are needed before recommending antiseptic mouthwashes for SARS-CoV-2 prevention or management.

BackgroundAn upsurge in Streptococcus pyogenes infections 2022-2023 highlighted potential benefits of point-of-care tests (POCT) to support clinical pathways, prevent outbreaks, and optimise antibiotic use. ObjectivesWe conducted a pilot research study in a west London paediatric emergency department (ED) to determine whether a molecular POCT had potential to alter management in children who were also having a conventional throat swab taken for culture. MethodsChildren <16 years presenting to ED who had a throat swab requested by a clinician were invited to have a second swab taken for research purposes only. Clinical management was unaffected by the research swab result, which was processed using a molecular POCT that was not approved for use in the host NHS Trust. ResultsPrevalence of streptococcal infection was low during the study (May 2023-June 2025); swab positivity in symptomatic children was 12.8% (6/47). Overall, 38/49 (77.6%) participants who had throat swabs received antibiotics. Of those children recommended to receive antibiotics, 29/38 (76.3%) had a negative POCT. Mean time to reporting of positive throat swab culture results was 3.67 days (range 3-5 days) leading to occasional delay in treatment, although POCT identified positive results within minutes. ConclusionAntibiotic use was frequent and could be avoided or stopped by use of a rule out POCT in over three-quarters of children in the ED, if suspicion of S. pyogenes is the main driver for prescribing. POCT were easy to process and produced immediate results compared with culture, in theory enabling timely decision-making and avoiding treatment delay.

Background: The choice of hand-drying method affects microbial contamination levels but its economic consequences have not been systematically quantified. Methods: By applying a quantitative microbial risk assessment framework, we translated the documented contamination differential between jet air dryers and paper towels into infection risk estimates, and embedded these into an established health economic model of healthcare-associated infections in NHS hospitals and an illustrative productivity analysis for the EU workforce. Results: The median estimated avoidable HCAI cost attributable to jet air dryer presence in UK NHS clinical areas was 58 million pounds per year, representing 2.1% of total HCAI expenditure for the affected hospital population, with a 50% certainty interval of 33-84 million pounds. Extended to the EU workforce, the same contamination differential implied a median of 1.7 billion euros in annual productivity gains, due to reduced absenteeism, for a shift to use of paper towels in public restrooms. Conclusions: These findings suggest that hand-drying method selection carries measurable economic implications that are not currently reflected in facility management practice. The evidence supports the prioritisation of paper towels in clinical and public settings as a cost-effective infection control measure

BackgroundAntimicrobial resistance (AMR) surveillance is essential for quantifying and monitoring the burden of AMR among World Health Organization (WHO) priority pathogens. We analysed Tunisian AMR surveillance system (TARSS) data across five sentinel hospitals from 2014 to 2022. MethodsWe conducted a retrospective isolate-level analysis for Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter spp. Temporal, ward, and specimen associations were quantified using multivariable logistic regression models. Sex and age categories were explored in secondary models due to missingness. Temporal trends were assessed using Cochran-Armitage test, and co-resistance was summarised for third-generation cephalosporin and carbapenem phenotypes. We also evaluated temporal dynamics of 3GCR and CR profiles. ResultsA total of 35,525 E. coli, 14,325 K. pneumoniae, 9,679 P. aeruginosa, and 5,597 Acinetobacter spp. were reported to TARSS between 2014 and 2022. Mean annual MDR prevalence was high for Acinetobacter spp. (85.1%), moderate for K. pneumoniae (45.5%) and for P. aeruginosa (27.1%), and lower for E. coli (17.5%). Adjusted models indicated increased odds of resistance to several antibiotics, whereas E. coli showed decreased odds. Intensive care unit (ICU) and blood isolates were associated with higher odds of resistance in all pathogens. ConclusionThis nine-year multi-hospital analysis reveals a high prevalence of AMR across the four WHO priority pathogens, settings, and specimen types, with increasing resistance for some pathogen-antibiotic combinations. The higher odds of clinically important resistance amongst ICU and blood isolates support the use of ward-level antibiograms and stratified stewardship and infection prevention measures.

BackgroundChest tube infection is one of the complications of the tube thoracostomy. Infectious complications may develop in 2% to 25% of patients who undergo thoracotomy tube placement. The use of prophylactic antibiotics to prevent infections associated with thoracostomy tubes remains a subject of debate. Current practices in managing infections related to tube thoracostomy are hindered by the lack of comprehensive and localised data on the microbial profile and their resistance patterns. ObjectiveTo determine the prevalence of thoracostomy tube infections and associated clinical characteristics among patients treated with a thoracostomy tube at KCMC Zonal Referral Hospital. MethodologyProspective cohort study done at KCMC Zonal Referral Hospital. Include all patients undergoing thoracostomy tube insertion from September 2024 to April 2025. ResultsA total of 84 patients underwent tube thoracostomy during the study time. Of these 22 (26.2%) developed SSI. Out of the 22 samples collected, 17 (77.3%) had positive culture results. The most commonly identified pathogens were Pseudomonas aeruginosa (41.2%) and Staphylococcus aureus (29.4%). The highest overall susceptibility was observed with amikacin, effective against 10 (58.8%) of the tested organisms. The most common resistance was observed against ceftazidime (56.3%) and piperacillin-tazobactam (50.0%). Prolonged chest tube duration (>7 days) was the strongest independent predictor of tube thoracostomy infection. ConclusionThis study revealed a high prevalence of tube thoracostomy infection. Prolonged tube duration and admission to a non-surgical ward care emerge as key risk factors for SSI. These findings underscore the importance of limiting chest tube duration when clinically feasible and ensuring optimal postoperative care environments to minimise the risk of infection.

Background Antibiotic use is prevalent in hospitals, driving the emergence of drug-resistant pathogens. We investigated the contextual influences on antibiotic prescribing behaviour across hospitals in high, middle, and low-income countries in Asia with an aim to provide actionable insights to improve prescribing behaviour. Methods We conducted a large qualitative study across ten institutions in Singapore, Nepal, and Thailand. Semi-structured interviews and ethnographic observations involving physicians, nurses, pharmacists, and management staff were conducted. Data were analysed thematically using QSR NVivo 14. Findings A total of 194 interviews were conducted amongst physicians (54{middle dot}1%), nurses (19{middle dot}6%), pharmacists (12{middle dot}4%), and management staff (13{middle dot}9%). Structural factors such as limited microbiology laboratory capabilities, concerns about antibiotic quality, weak infection prevention and control policies, and the lack of relevant, updated guidelines were prominent drivers for prolonged and broad-spectrum antibiotics prescriptions. Where these system supports were in place, prescribing decisions were less defensive and more targeted, although prescriber responsibility and concerns about immediate patient deterioration continued to influence practice. Across settings, clinicians tended to prioritise short-term perceived benefits of antibiotic treatment over the longer-term risks of antimicrobial resistance.

Endocavity ultrasound transducers, particularly transvaginal ultrasound (TVUS) probes, contain intricate structures such as notches, grooves, lens surfaces, and handle edges that are highly susceptible to microbial contamination yet difficult to disinfect using conventional high-level disinfection (HLD) methods. This study evaluated the efficacy of a novel ultraviolet-C light-emitting diode (UV-C LED) HLD system in eliminating microbial contamination from these complex probe surfaces. Two TVUS probes were sampled from predefined high-risk regions before and after disinfection following clinical use. Probe A was sampled at the top and bottom notches and both sides of the handle, while Probe B was assessed at the lens, edges, and bent groove regions. Microbial contamination was quantified using swab sampling, culture on agar plates, and identification via MALDI-TOF. Environmental sampling of examination and disinfection rooms was also performed. To assess this system robustness, probe sites were repeatedly inoculated with Bacillus subtilis spores and evaluated following UV-C treatment. Before UV-C treatment, contamination rates ranged from 25% to 57% across sampled regions, with microbial loads reaching up to 3.9 log CFU. Identified organisms included Staphylococcus epidermidis, Pseudomonas koreensis, Bacillus cereus, and Propionibacterium spp. Probe sheaths were also predominantly contaminated with Staphylococcus epidermidis., with counts reaching up to 4.3 log CFU, Environmental sampling revealed diverse microbiota, with higher contamination levels in examination rooms compared to disinfection areas. Following 90 seconds of UV-C exposure, no microbial growth was detected on any sampled site, indicating 100% decontamination. Additionally, UV-C treatment achieved >6.7 log reduction of B. subtilis spores across all tested regions. These findings demonstrate that UV-C LED technology provides rapid, effective, and consistent high-level disinfection of complex TVUS probe surfaces, supporting its potential as a rapid and reliable disinfection modality in clinical setting.

Objective. To evaluate the diagnostic and prognostic significance of C reactive protein (CRP) level dynamics within the first five days after surgery for the early detection of surgical site infections (SSI) and to identify independent risk factors, taking into account regional specifics of surgical management (types of surgeries, duration of procedures), as well as the local hospital microbial landscape. Materials and Methods. A single-center retrospective cohort analysis of data from 127 patients who underwent surgical procedures between 2022 and 2024 was conducted. CRP levels on postoperative days 1, 3, and 5 were assessed, and delta values were calculated. Descriptive statistics, ROC analysis, and multivariate logistic regression were used to identify predictors of SSI. Results. Patients with SSI lacked the physiological decrease in CRP levels by day 5. The most informative indicator was the CRP level on day 3: a threshold of >106 mg/L was associated with a high risk of SSI (AUC=0.76; sensitivity 85%, specificity 63%). Independent predictors of SSI included surgery duration (OR=1.015 per 1 min; p<0.001) and the increase in CRP between days 3 and 5 (delta CRP3-5: OR=1.027; p=0.023). A combined model (clinical parameters + CRP) demonstrated the highest predictive ability (AUC=0.79). Conclusion. Monitoring CRP dynamics, particularly on days 3 and 5, is a highly informative and accessible method for the early diagnosis of SSI. A CRP threshold of >100 mg/L on day 3 and its subsequent increase should serve as a trigger for in-depth diagnostic investigation and rationalization of antimicrobial therapy. Keywords: C reactive protein, postoperative complications, surgical site infection, antibiotic therapy, predictive factors, diagnosis

Hospital-acquired infections driven by ESKAPEE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., and Escherichia coli) are highly prevalent. Premise plumbing, sinks and drains, seeds these organisms into patient environments via aerosolization and subsequent surface contamination. We measured viable ESKAPEE pathogens and overall microbial communities in and around sinks in two high-burden hospitals in La Paz, Bolivia, using culture and 16S rDNA sequencing. In a prospective observational study (May-August 2025), we collected 233 surface swabs and 39 air samples across four sink-related surface categories and in room air. Samples were plated on selective media for ESKAPEE identification and quantified as colony-forming units (CFU) normalized to 100 cm2 or 6000 L. DNA was extracted, and the full 16S rDNA gene was sequenced on PacBio Revio, analyzed via DADA2/QIIME2 and R. We detected viable presumptive ESKAPEE pathogens in 74.7% surface swabs and 74.4% air samples. Sink basins were most contaminated (mean 31CFU/100 cm2, 95 % CI16-46); concentrations declined with distance from the drain. Klebsiella/Enterobacter spp. showed the highest mean concentration across samples; S. aureus was most frequently detected (54.4% of samples). Hospital-specific differences were evident in culture positivity (Hospital A 85% vs. Hospital B 66.9%) and community composition (PERMANOVA P = 0.001; sample location explained 21.9% vs. 11.7% of variation). 16S profiling confirmed elevated relative abundances of Klebsiella, Enterococcus, and Enterobacter in basins relative to distant surfaces and air. The hospitals studied had high levels of ESKAPEE pathogens, underscoring the need for control measures.

BackgroundIn long-term care facilities (LTCFs), close-contact identification often relies on staff recall and monitoring records because residents may be unable to self-report reliably. How these different record-generation processes relate to proximity-based sensor measurements in routine LTCF workflow remain unclear, and how such differences may influence contact-based decision-making in outbreak response is not well understood. MethodsWe conducted a five-day observational study in a Japanese LTCF using ultra-wideband (UWB) indoor positioning. Twenty-seven participants wore UWB tags, including 16 residents and 11 staff members; 10 staff members completed questionnaires. We compared UWB-derived proximity with questionnaire-derived contacts from staff self-report and monitoring-based proxy records, and assessed directional discrepancies under multiple distance-time thresholds. ResultsQuestionnaire-based records and UWB-derived proximity showed different patterns of discrepancy across contact types. Within this facility, resident-related monitoring-based proxy records showed relatively small directional discrepancies, whereas staff self-reports tended to identify additional resident-staff contacts under the baseline threshold ([&le;]1.0 m for [&ge;]15 min). Several alternative thresholds were associated with discrepancies closer to zero than the baseline, although the apparent ranking varied by summary metric. ConclusionsIn this single-facility observational study, different contact-list generation processes were associated with different patterns of discrepancy relative to a proximity-based operational measure. These findings support interpretation in terms of workflow-specific contact-list generation rather than a single universally optimal threshold and may help inform facility-level review of contact identification practices in LTCFs. These findings support aligning contact identification strategies with facility-specific workflows to improve the feasibility and effectiveness of IPC practices in LTCFs.

BackgroundVirtual colony count is a kinetic, 96-well turbidimetric assay that has been used since 2003 to determine the antimicrobial activity of antimicrobial peptides including the defensin HNP1. Virtual colony count results differed from traditional colony counting results in studies of the antimicrobial activity of the human cathelicidin LL-37 and related peptides. The difference could possibly have been caused by an inoculum effect. MethodsThe virtual colony count assay was conducted using inocula that varied from 1250 to 1x108 virtual colony forming units (CFUv) per milliliter. ResultsThe virtual colony count assay demonstrated a pronounced inoculum effect of HNP1 against Staphylococcus aureus ATCC 29213, accompanied by biofilm formation observed in the wells of the 96 well plates at all inocula. The S. aureus inoculum effect was not as drastic as previously reported for Escherichia coli. ConclusionsThe inoculum effect is further evidence that biofilm formation is a resistance mechanism used by a variety of bacteria against antimicrobial peptides such as HNP1.

Background: Particulate matter (PM) exposure is associated with increased risk and exacerbation of chronic rhinosinusitis (CRS), yet underlying mechanisms remain poorly understood. Methods: Human nasal epithelial cells obtained from ethmoid tissue of CRS (n = 5) and control donors (n = 4) were cultured at an air-liquid interface and exposed to PM. Single-cell RNA sequencing was performed to characterize PM-induced cellular and transcriptional changes. Protein expression, epithelial barrier integrity, cell death, and intracellular PM uptake were evaluated using biochemical, imaging, and ultrastructural approaches. Results: Unsupervised clustering identified seven epithelial cell populations. Gene set analysis revealed baseline enrichment of inflammatory and keratinization pathways and reduced ciliogenesis in CRS compared with controls. Although PM induced inflammation and squamous differentiation in controls, the pathogenic responses were significantly amplified in CRS, including uniquely enhanced IL-1 signaling. Transcriptional changes were validated by ELISA, transepithelial electrical resistance, and immunofluorescence, demonstrating increased inflammation, epithelial barrier disruption, and cell death following PM exposure. Transmission electron microscopy revealed increased intracellular PM within membrane-bound organelles. Pre-treatment with an endocytosis inhibitor rescued PM-induced epithelial barrier dysfunction and inflammation. Conclusion: CRS epithelium exhibits baseline dysfunction that may predispose it to environmental injury. PM exposure both induces CRS-like epithelial changes in controls and exacerbates disease-associated phenotypes.

BackgroundPhage therapy is increasingly considered a promising alternative for treating multidrug-resistant (MDR) infections. However, its clinical application remains limited by challenges in isolating effective phages against resistant clinical strains and by the limited ability of in vitro assays to predict performance in real biological environments. While biological matrices are known to influence phage activity, these effects are not well characterised. MethodsA phage-resistant Pseudomonas aeruginosa isolate from a patient with recurrent MDR urinary tract infection was used as the model organism. Conventional isolation methods failed to recover effective phages, leading to the development of TEASER-i (Transient EDTA- and Ion-Assisted Sequential Enrichment & Recovery). Recovered phages were characterised using adsorption assays, one-step growth kinetics, and time-kill experiments. Their antibacterial activity was evaluated both in vitro and in ex vivo human matrices (whole blood, serum, plasma, and urine). Phage efficacy was quantified using maximum log reduction (Emax), area under the curve (AUC), and phage-to-bacteria ratio (PBR). ResultsA novel TEASER-i method optimised for difficult-to-treat Gram-negative infections, enabled recovery of a functionally effective Osewage-derived P. aeruginosa phage, which outperformed a Ourine-derived P. aeruginosa phage that showed slower replication and lower burst size. Phage activity varied significantly in blood, serum, and plasma. Urine supported the most sustained antibacterial effect. In many cases, early bacterial reduction was followed by regrowth. Sustained activity was associated with maintenance of favourable PBR values, while negative PBR corresponded to treatment failure. At 96 h, only two conditions maintained favourable phage load (log 10 PBR > 0): the S. aureus phage in urine (+1.66) and the sewage-derived P. aeruginosa phage in serum (+1.32). ConclusionsPhage efficacy depends not only on intrinsic lytic capacity but also on the ability to persist and amplify within specific biological environments. Conventional isolation and in vitro screening may therefore overestimate therapeutic potential. Combining optimised isolation strategies with ex vivo evaluation provides a more realistic framework for phage selection and clinical translation.

BackgroundTransfer of Streptococcus agalactiae, or Group B Streptococcus (GBS) from parent to newborn during delivery can produce life-threatening infections in neonates. Probiotics could potentially prevent GBS colonization in pregnant individuals. We conducted a systematic review and meta-analysis to evaluate the effectiveness of probiotic administration in treating Group B Streptococcus colonization. MethodsMEDLINE, ClinicalTrials.gov, PROSPERO, and the Cochrane, Wild Card, Central Register of Controlled Trials were searched from the July 2015 of each database until July 2025 that completed a randomized controlled trial which compared Probiotic versus control. We utilized the Cochrane Risk of Bias 2.0 (RoB 2) tool to assess bias in the systematic review. Results14 randomized controlled clinical trials met our inclusion criteria. The trials used oral probiotic administration compared to either a placebo or a control group. A meta-analysis showed that probiotic administration produced a statistically significant decrease in the rate of GBS colonization in pregnant individuals. The individual studies ranged from four showing great effectiveness, while the other 10 studies showed a range of effectiveness, from partially effective to no effectiveness in preventing GBS colonization. ConclusionOverall, probiotics were effective in lowering infection rates of GBS, but individual studies showed great variability. Probiotics show promise in decreasing GBS colonization in pregnant people, but more studies need to be performed in order to use them effectively and decrease antibiotic usage.