Tuft cells (TCs) act as crucial airway sentinels that detect bacterial metabolites and initiate immune responses, yet the underlying mechanisms remain poorly understood. Here, we identify tracheal TCs as the initial source of leukotrienes (LTs), released during bacterial infection. Tracheal TCs discriminate pathogenic from commensal bacteria by sensing extracellular ATP (eATP) released by pathogens, including Pseudomonas aeruginosa and Rodentibacter pneumotropicus, within 4 h of infection, through the transient receptor potential cation channel subfamily M member 5 (Trpm5). This induces the LT release, including LTB4, and promotes rapid recruitment of neutrophils and macrophages to the trachea and alveolar spaces. Trpm5-/- mice failed to detect bacterial eATP, exhibited neutrophil sequestration in the spleen, and became colonized following R. pneumotropicus infection, while Trpm5+/+ mice efficiently cleared the pathogen. These findings uncover a critical TC-dependent sensing mechanism in pneumonia, establishing TCs as both ATP sensors and triggers of acute innate immune responses.

While extracellular vesicles (EVs) are established mediators of intra-species signaling, their contribution to cross-kingdom communication remains incompletely understood. Here, we investigate the EV-mediated interactions between human colon epithelial cells and both Gram-positive and Gram-negative gut bacteria. We show that bacterial EVs (BEVs) derived from Lacticaseibacillus casei, Enterococcus faecalis, and Proteus mirabilis induce distinct transcriptomic changes in Caco-2 cells depending on the bacterial species, with up to ~6,000 differentially expressed genes, including CCL20, CXCL8, or CXCL10. Transfection of BEV-derived RNA independently induces a subset of similar effects, indicating that the EV-mediated communication is partially driven by the RNA cargo. Conversely, we demonstrate that bacteria interact with Caco-2-derived EVs and miR-192-5p, which is highly abundant (~36.4-fold higher) in EVs isolated from conditioned medium compared with EVs from unconditioned medium, with modest effects on bacterial growth. Furthermore, we show that lipid-based packaging of miR-192-5p modulates its association with the bacteria. Our findings support a conceptual model in which EVs and their RNA cargo contribute to species-dependent host-microbe interactions. This study introduces a framework for understanding EVs as cross-kingdom regulators and underscores the importance of tailored, context-specific analyses for understanding the scope of EV-mediated interactions in microbiome-host homeostasis and disease.

Abstract The rise of antimicrobial resistance warrants renewed attention to established but overlooked antibiotics such as nitroxoline (NTX). Here, we systematically dissect NTX’s mode of action and investigate the contribution of its first-pass metabolites, NTX-sulphate and NTX-glucuronide. We identified metallophore-mediated cellular iron deprivation as the principal antibacterial mechanism of NTX, characterized by induction of iron acquisition pathways and Fe–S cluster proteins, and concomitant loss of protein-bound iron. In contrast, NTX metabolites were biologically inactive and lacked metal-chelating properties. Ex vivo assays demonstrated that clinically relevant uropathogens, including Escherichia coli and Klebsiella pneumoniae, efficiently reconvert these metabolites into active NTX in human urine. Together, our findings establish a mechanistic framework linking NTX antibacterial activity, host detoxification, and pathogen-dependent metabolite reactivation, and providing a molecular explanation for NTX’s enduring therapeutic potential and favourable safety profile .

Objective Practical courses in medical microbiology aim to translate theory into hands-on skills, but students often struggle to link laboratory techniques with diagnostic procedures. Formative testing and self-assessment enhance knowledge retention and metacognitive awareness. This study aims to integrate quiz-based self-assessment using an audience response system (OnlineTED) into a microbiological practical course to evaluate feasibility and explore whether quiz-based self-assessment is associated with differences in students' perceived learning outcomes, satisfaction, and engagement. Methods Medical students ( n = 125) in their first clinical year participated in a diagnostic practical at Saarland University in 2023/24. Two cohorts were compared: an intervention group using OnlineTED-based quizzes during each course day and a control group without quizzes. Standardized evaluations assessed satisfaction, clarity of objectives, perceived workload, and learning outcomes in both cohorts. Results Overall evaluations were very high in both groups. No statistically significant differences were observed between groups, likely reflecting a ceiling effect. Descriptive differences in the distribution of top ratings were observed in favor of the quiz cohort: more students awarded the top rating for clarity of learning objectives (57.9% vs 28.6%), relevance for the final exam (63.2% vs 38.1%), and learning outcome (68.4% vs 42.9%). In the quiz cohort, aggregated quiz accuracy increased from 63.6% on day 1 to 88.8% on day 6. Similarly, mean examination scores were descriptively higher in the quiz cohort and increased from 6.65 to 7.10 points, while the exam failure rate declined in the quiz group (15.87% vs 11.29%). Day-specific evaluations indicated variation in perceived success and sufficiency of time, highlighting sessions requiring adjustment. Conclusion Integrating interactive quizzes was feasible, well accepted, might enhanced students perceived learning goals and provided valuable feedback for supervisors without increasing workload or reducing satisfaction. As structured evaluations, quizzes can guide targeted curriculum adjustments and optimization.

Abstract Background Enterococcus faecalis is a common gut commensal Gram-positive bacterium that can act as an opportunistic pathogen and is frequently associated with severe infections community-acquired and nosocomial. Bacteria-derived extracellular vesicles (EVs) emerge as key mediators of host-bacteria communication with immunomodulatory roles and mechanistic participation in pathophysiological processes. However, the impact of E. faecalis-derived EVs (Ef-EVs) on host cells and their potential role in shaping host responses during infection remain unclear. Methods Ef-EVs from the E. faecalis DSM 20478 type strain and four independent clinical bloodstream isolates were isolated via ultracentrifugation and size exclusion chromatography. EVs were characterized by nanoparticle tracking analysis and cryogenic transmission electron microscopy. Immunomodulatory effects of Ef-EVs were studied in vitro on NF-κB/AP-1 reporter cells, primary human monocyte-derived macrophages, and human umbilical vein endothelial cells, and by transcriptomic analysis of macrophages isolated from in vivo EV-treated zebrafish larvae. EV-induced signaling mechanisms were studied using uptake inhibitors as well as bottom-up assembled bacterial EVs functionalized with synthetic bacterial ligands. EV-induced metabolic reprogramming in macrophages was investigated by RNA-Seq and live-cell metabolic analyses using the Seahorse XFe-96 Flux Analyzer. Results We found that Ef-EVs can induce pro-inflammatory responses in host macrophages via Toll-like receptor 2 (TLR2) signaling, as demonstrated using TLR2 transgenic cell lines and a TLR2-blocking antibody. Using uptake inhibitors as well as bottom-up assembled bacterial EVs functionalized with synthetic bacterial ligands as a minimalistic approach to study mechanisms of EV signaling, we demonstrated that Ef-EVs target the plasma membrane TLR2 to induce inflammation in a process uncoupled from their internalization. Furthermore, we found that Ef-EVs induce metabolic reprogramming towards a pro-inflammatory, glycolytic phenotype. Conclusion Our findings reveal a mechanism by which Gram-positive bacterial EVs modulate immune signaling and metabolic pathways, advancing our understanding of host-pathogen communication.

By assessing public awareness, preventive behavior, and knowledge regarding invasive mosquito species in Saarland, Germany, a non-endemic region at increasing invasion risk, this study aimed to explore how the introduction of invasive mosquitoes can be addressed in non-endemic areas. A population-based anonymous questionnaire in Saarland was conducted from February to June 2024. Participants were recruited through broad public dissemination using digital and analog approaches. Nine items assessed mosquito protection practices, knowledge of invasive species, and potential for pathogen transmission. Among 1064 respondents, 623 (58.6%) met the inclusion criteria. While over half of them recognized stagnant water removal as an effective preventive measure, fewer than one fifth practiced it regularly. Travel medicine consultations were associated with greater use of protective clothing. Among participants aged 26-35, men were more likely than women to report no prior engagement with mosquito prevention measures. Although most participants had heard of Aedes albopictus, fewer than half linked it to chikungunya transmission. Marked discrepancies persist between general awareness and evidence-based preventive behavior. Targeted seasonal education campaigns represent a modifiable lever to delay vector establishment and improve outbreak preparedness.

Given the global threat of increasing antibiotic resistance, risk factor detection of multi-resistant pathogens is particularly important. This is complicated by different definitions, using the international extended spectrum beta-lactamases (ESBL) definition and the German definition of multidrug-resistant Gram-negative pathogens (MRGN). Although the MRGN definition was primarily introduced for hospital hygiene measures, it is often used in outpatient or semi-inpatient areas. Due to the increasing numbers of outpatient treatments of the healthcare system, corresponding data is necessary for specific hygiene regulations. This study provides MRGN and ESBL data based on a stool examination and a questionnaire evaluation in the period 07/2021-03/2022 of 231 outpatients of Saarland University Medical Center before traveling abroad. There was a 3MRGN prevalence of 2.6% with five Escherichia coli and one Klebsiella pneumoniae and an ESBL prevalence of 5.6% with 13 ESBL Escherichia coli, four of which could also be classified as 3MRGN. These prevalences were compared with MRGN/ESBL prevalences in PubMed and Google Scholar in different areas of the German healthcare system in the period 2013-2024 at the federal state level. The selective literature search revealed geographical differences and missing prevalence data depending on the healthcare sector (outpatient/inpatient) and federal state. Resistance data is often evaluated according to international standards, i.e. according to the ESBL definition. Outpatient MRGN prevalences are hardly known despite the increasing numbers of outpatients of the healthcare system. Due to the scarcity of outpatient data, our study from a travel medicine clinic provides interesting epidemiological data that should be considered in the context of the COVID-19 pandemic.

To investigate the microbiological etiology of endogenous and exogenous postprocedural infectious endophthalmitis in patients referred to two tertiary eye care centers in the German federal state of Saarland over a five-year period (2019–2023). We retrospectively analyzed all cases of endophthalmitis treated at two ophthalmological centers in southwest Germany between January 1, 2019, and December 31, 2023. Included were only those cases for which vitreous aspirate specimens were subjected to microbiological analysis. Cases of exogenous endophthalmitis secondary to other ocular or periocular infections (e.g., microbial keratitis) or trauma were excluded. Microbiological pathogen identification was performed using Gram stain microscopy, conventional bacterial and fungal cultures, as well as broad-range bacterial and fungal polymerase chain reaction (PCR), followed by sequencing in PCR-positive samples. A total of 126 endophthalmitis vitreous aspirate samples from 126 patients with a mean age of 73.3 ± 11.4 years were included. The majority of endophthalmitis cases occurred after intravitreal injection (55.6

Inflammatory skin conditions like Acne inversa are characterized by dysbiosis, an imbalance of commensal and pathogenic bacteria, posing challenges for specific treatments. Consequently, we investigated how biofilm formation, low-nutrition skin environments, and air interfaces influence susceptibility to anti-infective treatments in mixed bacterial cultures. To achieve this in a cost-effective and reproducible manner, we developed a simplified substrate made of gelatin, hyaluronic acid, chondroitin sulphate, and alginate (=Gel-Alg). This in vitro model simulates biofilm cultivation on skin surfaces for aerobic bacteria. We selected Staphylococcus aureus and Staphylococcus epidermidis as two clinically relevant strains, which are also abundant in Acne inversa. We tested single and mixed cultures under different conditions: (i) nutrient broth, (ii) Gel-Alg substrate, (iii) EpiDerm™ commercial skin model, and (iv) ex vivo human skin. Proliferation, measured by colony-forming units, was comparable across most conditions, except for human skin. Metabolic activity, assessed via Presto Blue staining, revealed significant differences. Dual-species cultivation and quantification by viability PMA qPCR indicated dominance of S. epidermidis over S. aureus in skin-like environments. Treatments with biofilm-dissolving rhamnolipids, the antibiotic vancomycin, and combinations thereof demonstrated varying efficacy in single and mixed cultures. While the drug combination could almost completely eradicate staphylococcal biofilms in broth, susceptibility varied in skin-like models and moreover strongly depended on temperature (37°C vs. 32°C). In conclusion, this study suggests that reductionistic models, while mimicking key features, could be valuable for early selective antimicrobial drug development for specific applications like Acne inversa therapy.

Overview: SeptiCyte RAPID is an FDA-cleared gene expression test that quantifies host immune response to aid in the diagnosis of sepsis. The test yields a score (the SeptiScore) ranging from 0–15, distributed across four bands (1–4) based on increased likelihood of sepsis. Each band can be characterized by average positive and negative likelihood ratios (LR+ and LR−, respectively) for the discrimination of sepsis versus the non-infectious systemic inflammatory response syndrome (SIRS). Methods: A retrospective analysis of prospectively collected data from a combined cohort of critically ill patients suspected of sepsis (n = 889), recruited across 19 hospitals in the USA and Europe. The analysis quantified the LR+ and LR− parameters as a function of SeptiScore, for discrimination of sepsis vs. SIRS in patients admitted to ICU. Hypotheses: (1) The likelihood ratio (LR) framework provides a clinically useful interpretive approach that complements the previously used SeptiScore banding scheme; (2) Low Band 1 SeptiScores are associated with sufficiently small LR− to support the use of SeptiCyte RAPID as a rule-out test for sepsis; (3) High Band 4 SeptiScores are associated with sufficiently large LR+ to support the use of SeptiCyte RAPID as a rule-in test for sepsis; and (4) SeptiScore-derived LR+ and LR− values can be combined with estimates of pre-test probability (derived from patient characteristics and/or other diagnostic tests) to generate individualized, patient-specific post-test probabilities of sepsis. Results: The SeptiCyte RAPID test demonstrates strong diagnostic performance in distinguishing sepsis from SIRS. The likelihood ratios across different score bands provide clear clinical utility: the median LR+ was 3.26 (range 2.57–4.24) for Band 3, and 6.97 (range 4.35–15.57) for Band 4, providing evidence toward ruling in sepsis at high SeptiScores. Conversely, the median LR− was 0.16 (range 0.14–0.20) for Band 2 and 0.085 (range 0.014–0.16) for Band 1, providing evidence toward ruling out sepsis at low SeptiScores. A higher-resolution analysis of SeptiCyte RAPID performance confirmed these trends by evaluating LR+ and LR− at specific values within each band. The sepsis group was further stratified according to whether patients were classified as blood culture positive (BC+) or blood culture negative (BC−), and the detailed LR+ and LR− analyses were repeated. A monotonic increase in likelihood ratio with increasing SeptiScore was consistently observed, independent of whether sepsis patients were culture-positive, culture-negative, or unstratified with respect to blood culture status. Conclusions: High SeptiScores have correspondingly high LR+ values, and low SeptiScores have correspondingly low LR− values, both of which may have clinical utility. High likelihood ratios for Band 4 SeptiScores, which precede traditional microbiology results, may provide clinicians with early confidence of a sepsis diagnosis and microbiology diagnostic stewardship. Low likelihood ratios for Band 1 SeptiScores may prompt clinicians to consider an alternate diagnosis to sepsis. These are diagnostic-performance-based observations; whether they translate into fewer missed diagnoses or more efficient use of hospital resources has not been directly assessed in this study and will require dedicated clinical outcome studies.

War injuries are characterized by a high incidence of bone and soft tissue infections caused by multidrug-resistant (MDR) pathogens. We analyzed the influence of infections with MDR pathogens on the course and outcome of 17 Ukranian patients within the first three years of surgical therapy. To assess the clinical course of Ukrainian war-wounded patients treated in our tertiary care hospital between June 2022 and May 2025, the characteristics of hospital stay, number of operations, bacterial spectrum of wound infections and antibiotic therapies were analyzed retrospectively. Patients had sustained mostly severe extremity injuries several months (105.3 ± 25.1 days) prior to admission. The average length of hospital stay was 165.6 ± 29.6 days. An average of 13 ± 3 operations were performed per patient during this time. Secondary limb amputation was required in 3/17 patients (18

Background Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by progressive biliary destruction and cholestasis. Current therapies, including ursodeoxycholic acid (UDCA), exhibit limited efficacy in advanced disease. In this study, we investigate the therapeutic potential of microbial intervention using Lactobacillus rhamnosus (Lbr) in the Mcpip1fl/flAlbCre knockout mouse model of PBC, which we described previously. Knockout mice develop human PBC-like features such as bile acid dysregulation, autoantibodies, cholangiocyte hyperplasia and fibrosis. Methods Six-week-old Mcpip1fl/fl (wild-type) and Mcpip1fl/flAlbCre (knockout) mice were treated with Lactobacillus rhamnosus supplementation, UDCA (15 mg/kg/day), UDCA + Lbr, and UDCA + OCA (obeticholic acid, 10 mg/kg/day) for six weeks. Treatment response was characterized by liver and gut pathology, serum biomarkers, transcriptomic profiles, and microbiome composition. Results Treatment of Mcpip1fl/flAlbCre animals with Lbr decreased serum bile acids and reduced pathological cholangiocyte dysplasia in the liver, decreased leukocyte infiltration and fibrosis. RNAseq of liver tissue revealed enrichment of humoral immune responses and T cell activation pathways in knockouts, all of which were significantly attenuated by Lbr monotherapy. Gut pathology marked by increased intraepithelial lymphocyte infiltration and mucosal hypertrophy, was also normalized upon Lbr administration. Finally, probiotic treatment modulated the microbiome by increasing the Firmicutes/Bacteroidetes ratio and enriching butyrate-producing Lachnospiraceae. Administration of UDCA and UDCA+OCA had less pronounced effects: only decreased serum bile acids was detected in both groups. Conclusions Probiotic intervention with Lbr represents a feasible strategy to attenuate fibrotic progression in a mouse model of autoimmune cholestatic disease by modulation of the gut-microbiome-immune crosstalk.

Background: Dental unit waterlines (DUWL) might pose infection risks due to the presence of biofilms. A global outbreak of Mycobacterium (M.) chimaera through water-carrying medical devices in cardiac surgery highlighted the importance of water for pathogen transmission. We aimed to assess the presence of non-tuberculous mycobacteria (NTM), Legionella spp., and Pseudomonas (P.) spp. in DUWLs in one tertiary medical centre in Germany to evaluate their potential role as causative agents of infections linked to dental procedures. Methods: We conducted a cross-sectional, microbiological single-centre study at Saarland University Medical Centre in Homburg, Germany from May to July 2024. We examined 42 DUWLs once before the daily patient care started. After DUWL flushing, 500 mL water samples were collected. Legionella spp. were detected after up to 10 days of incubation, Pseudomonas (P.) spp. via membrane filtration and 48-hour incubation, and NTM using liquid and solid cultures with up to eight weeks of incubation. Clinically relevant NTM species such as M. chimaera and M. chelonae were identified using a GenoType line probe assay. We calculated frequencies and proportions of positive samples. Results: Bacterial growth was detected in 36 of 42 water samples. A total of 43 NTM species were detected in 35 (83%) water samples. The most common species was M. chimaera (n=27), followed by M. chelonae (n=7), M. gordonae (n=4), M. interjectum (n=4), and M. mucogenicum (n=1). Multiple NTM species were detected in five samples, including one with four distinct species. One specimen contained only Legionella spp., while two of the samples harbored two pathogens each: P. aeruginosa with M. chimaera, and Legionella spp. with M. chelonae. Conclusion: The large proportion of NTM detection highlights the importance of frequent bacterial monitoring in DUWLs for enhanced water quality control, which is not commonly implemented. Further research is needed to address the clinical relevance of NTM in DUWL and to evaluate measures to improve patient safety, such as the use of various disinfectant methods to sustainably reduce NTM concentrations.

Strongyloidiasis is caused by a parasitic worm, primarily Strongyloides stercoralis. In rural settings of Côte d’Ivoire, parasitological surveys have revealed that the prevalence of S. stercoralis infection can reach up to 50

Background A study was conducted to assess the safety and tolerability of the tetravalent live-attenuated dengue vaccine Qdenga (R), which received marketing approval in Germany in 2022. The study evaluated vaccine-related reactions in a predominantly dengue-na & iuml;ve population, highlighting the importance of post-marketing surveillance as an essential component of safety evaluation for newly licensed vaccines. Methods Following dengue vaccination, participants were recruited for an anonymous online questionnaire through the national 'Trav VacNet' network in Germany. The questionnaire focused on post-vaccination reactions up to 18 days after the first and second vaccination, as well as previous travel history and coadministration. Results The study included 1176 participants, with a median age of 39 years (IQR 28-56), 53.2% female (n = 625), 46.5% male (n = 547), and 0.3% non-binary participants (n = 4). After the first dose, 51% of the participants reported systemic reactions such as headache [40% (190/474)], weakness [40% (189/474)], and malaise [32% (154/474)], which were most pronounced between days 7 and 11 post vaccination. After the second dose, localized signs and symptoms such as pain at the injection site [22% (n = 55/250)] were more common. Fever was more common after the first dose [20% (96/474)] vs. 2% (6/250) after the second. Females reported significantly more reactions than males after both vaccinations (1st dose P = 0.0002; 2nd dose P = 0.0003). A total of 334 (28%) co-administrations were reported whereby assessing adverse events were reported in 47% (157/333) of participants, with the highest prevalence observed when combined with the Japanese encephalitis vaccine [56.8%, (42/74)]. Differences in age groups were observed, with a decrease in reactions in the elderly (>= 65 years). Conclusions Vaccine-related reactions were frequently reported, predominantly after the first dose in dengue-na & iuml;ve participants. Coadministration was a common strategy without significantly increasing side effects. The study provides important insights into reactogenicity and may help improve vaccination strategies in dengue-na & iuml;ve populations.

INTRODUCTION:Chagas disease (CD), caused by the protozoan Trypanosoma cruzi (T. cruzi), poses a major health challenge in Paraguay, especially in the resource-limited Chaco region. Rapid diagnostic tests (RDTs) are valuable tools to enhance diagnostic access. This study evaluates CD prevalence and risk factors in an indigenous community in the Paraguayan Chaco and validates the national RDT-based diagnostic algorithm for resource-limited settings against the recommended standard algorithm, which relies solely on conventional serological tests. METHODOLOGY:A descriptive cross-sectional study was conducted in Casanillo, Presidente Hayes, Paraguay. In July 2023, a two-week field campaign was executed using a non-probability convenience sampling method targeting individuals aged over 9 months. Screening involved a single RDT, with positives confirmed via enzyme-linked immunosorbent assay (ELISA). Algorithm accuracy was validated externally at the National Reference Laboratory of Paraguay against the standard algorithm, which, in this study, included an ELISA and Hemagglutination test. Discordant cases were resolved with a second ELISA or Immunofluorescence. RESULTS:The study involved 999 participants, with a median age of 26 years (IQR 12-45), and 51.1% were female. The RDT-based diagnostic algorithm showed 97.1% agreement (κ = 0.94, 95%CI: 0.90-0.98) with the standard algorithm. The RDT alone had 96.0% agreement (κ = 0.91, 95%CI: 0.87-0.96), while the confirmatory ELISA had 94.3% agreement (κ = 0.88, 95%CI: 0.83-0.93). The algorithm's sensitivity/specificity (95%CI) were 94.6% (89.2-97.8)/98.6% (96.1-99.7), with the RDT at 94.6% (89.2-97.8)/96.8% (93.6-98.7) and the ELISA at 96.9% (92.3-99.2)/92.7% (88.5-95.8). T.cruzi infection seroprevalence was 12.6% (95%CI: 9.56-16.52). Age, Sanapaná ethnicity, and awareness of CD vectors were significantly associated with infection odds. No significant associations were found with other typical CD risk factors, clinical history, or health habits. CONCLUSION:The study underscores the high burden of T. cruzi infection in indigenous communities in the Paraguayan Chaco, urging immediate interventions for improved diagnosis and treatment. The combination of RDTs with conventional serology for diagnostic screening in resource-constrained settings proved useful, and its further use is encouraged.

Francisella tularensis, the causative agent of tularemia, poses a challenge for diagnosis and treatment due to its diverse clinical presentations and low incidence. Hence, the awareness among clinicians is comparatively low. This study reports the clinical characteristics, diagnostic approaches, and treatment outcomes of tularemia cases at one tertiary center in Germany over a 12-yearperiod.This retrospective monocentric case series considered all tularemia cases diagnosed at Saarland University Medical Center in Homburg, Germany between January 2013 and December 2024. Cases were identified from electronic medical records, and the certainty of tularemia was graded as definite, probable and possible infection, based on results of serology, polymerase chain reaction (PCR) assays, or blood cultures. Clinical data were extracted from patient records and supplemented by follow-up information from the clinicians.We identified 14 tularemia cases, including 6 definite as well as 3 probable and 5 possible cases. The clinical presentation was highly variable, with the (ulcero-)glandular form being the most common entity (10/14). Invasive diagnostics or surgery were required in eleven out of 14 patients. Initial misdiagnosis was common, leading to delayed diagnosis and multiple courses of ineffective antibiotics. Definite treatment included fluoroquinolones or doxycycline, and led to resolution of symptoms in most patients.The varied clinical manifestations of tularemia, from classic (ulcero-)glandular forms to severe and atypical presentations illustrate its diagnostic and clinical complexity. Enhanced awareness and early consideration are crucial, especially in endemic areas or patients with anamnestic environmental exposures.

Staphylococcus argenteus is a recently described member of the Staphylococcus aureus complex. Thus far, its frequency in clinical samples has been rarely described. Following an update of the commercially available matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) database (Bruker Daltonics) for pathogen identification, isolates from our S. aureus biobank were reanalysed for the detection of potentially misdiagnosed S. argenteus isolates. Additionally, we assessed whether phenotypical characteristics can be used to differentiate between S. aureus and S. argenteus in routine microbiological diagnostics. Among 505 investigated isolates, no S. argenteus or another member of the S. aureus complex were found. Furthermore, the morphological difference could not reliably distinguish between S. aureus and S. argenteus, as the latter was significantly more often missed by the staff in our study. Continuous surveillance of S. argenteus is essential to more accurately understand its epidemiology.

BACKGROUND:International travellers have the potential to transmit multidrug-resistant bacteria. However, the role of hygiene measures during travel has yet to be investigated. METHOD:Travellers were asked about their use of disinfectants and hygiene behaviour. Stool samples were analysed for Gram-negative multi-resistant bacteria (MDRO). These data were analysed, and a new MDRO risk map was developed and compared with data from existing literature. RESULT:Of 214 travellers, 6 (2.8 %) tested positive for an MDRO before and 16 (7.5 %) after the trip, with travel in known high-risk MDRO areas. Most travellers, 174 (81.3 %), regularly used disinfectants; only 36 (16.8 %) did not. There was no statistically significant correlation between the use of a disinfectant and colonisation with MDRO. In our and comparable studies, a high-risk region on the risk map was associated with an increased number of MDRO or extended-spectrum beta-lactamase (ESBL) positive returns. CONCLUSION:Travellers showed a high willingness to use disinfectants. This preliminary study highlights the need for larger, randomized studies to better assess the true impact of hand disinfectants on MDRO acquisition.