Microbiota-Induced Type I Interferons Instruct a Poised Basal State of Dendritic Cells.

Environmental signals shape host physiology and fitness. Microbiota-derived cues are required to program conventional dendritic cells (cDCs) during the steady state so that they can promptly respond and initiate adaptive immune responses when encountering pathogens. However, the molecular underpinnings of microbiota-guided instructive programs are not well understood. Here, we report that the indigenous microbiota controls constitutive production of type I interferons (IFN-I) by plasmacytoid DCs. Using genome-wide analysis of transcriptional and epigenetic regulomes of cDCs from germ-free and IFN-I receptor (IFNAR)-deficient mice, we found that tonic IFNAR signaling instructs a specific epigenomic and metabolic basal state that poises cDCs for future pathogen combat. However, such beneficial biological function comes with a trade-off. Instructed cDCs can prime T cell responses against harmless peripheral antigens when removing roadblocks of peripheral tolerance. Our data provide fresh insights into the evolutionary trade-offs that come with successful adaptation of vertebrates to their microbial environment.

Analysing carbapenemases in hospital wastewater: Insights from intracellular and extracellular DNA using qPCR and digital PCR.

The widespread dissemination of carbapenem-resistant bacteria in wastewater systems, particularly from clinical sources, poses a significant public health risk. This study assessed the concentrations and distributions of extracellular DNA (exDNA) and intracellular DNA (iDNA) harboring carbapenemase genes in wastewater from six tertiary care hospitals in Germany. We collected a total of 36 samples, comprising six biological replicates from each hospital, and analysed them using quantitative real-time PCR (qPCR) and digital PCR (dPCR). The analysis targeted seven carbapenemase genes: blaNDM, blaKPC, blaIMP, blaVIM, blaOXA-23-like, blaOXA-48-like, and blaOXA-58-like across both DNA fractions. Our results revealed significant variability in the concentrations of exDNA and iDNA across the sampling sites, with iDNA typically present at higher concentrations. Using NanoDrop One spectrophotometry and the Qubit dsDNA kit, exDNA concentrations ranged from 2.7 to 7.7 ng/mL, while Qubit recorded lower values between 1.1 and 4.0 ng/mL. Conversely, iDNA concentrations were markedly higher, spanning from 42.3 to 191.7 ng/mL with NanoDrop and 12.0 to 46.5 ng/mL with Qubit, highlighting the variability between DNA types and quantification methods. Despite its lower concentrations, exDNA comprised up to 18.2 % of total DNA, highlighting its potential role in the horizontal transfer of antimicrobial resistance genes (ARGs). The study detected target ARGs in both DNA fractions at all sites, with notable differences in their concentrations; iDNA consistently exhibited higher levels of ARGs, with the highest concentrations reaching 10.57 ± 0.20 log gene copies per liter (GC/L) for blaVIM in iDNA and 6.96 ± 0.72 log GC/L for blaIMP in exDNA. dPCR demonstrated greater sensitivity than qPCR, especially effective for detecting low-abundance targets like blaOXA-23-like in the exDNA fraction. Additionally, qPCR's susceptibility to inhibition and contamination emphasizes the superior robustness of dPCR. This research highlights the need for improved monitoring and the implementation of advanced treatment technologies to mitigate ARG dissemination in wastewater.

Pre-traumatic antibiotic-induced microbial depletion reduces neuroinflammation in acute murine traumatic brain injury.

The connection between dysbiosis of the gut microbiome and diseases and injuries of the brain has attracted considerable interest in recent years. Interestingly, antibiotic-induced microbial dysbiosis has been implicated in the pathogenesis of traumatic brain injury (TBI), while early administration of antibiotics associates with improved survival in TBI patients. In animal models of TBI, short- or long-term administration of antibiotics, both peri- or post-operatively, were shown to induce gut microbiome dysbiosis but also anti-inflammatory and neuroprotective effects. However, the acute consequences of microbial dysbiosis on TBI pathogenesis after discontinuation of antibiotic treatment are elusive. In this study, we tested whether pre-traumatic antibiotic-induced microbial depletion by vancomycin, amoxicillin, and clavulanic acid affects pathogenesis during the acute phase of TBI in adult male C57BL/6 mice. Pre-traumatic microbiome depletion did not affect neurological deficits over 72 h post injury (hpi) and brain histopathology, including numbers of activated astrocytes and microglia, at 72 hpi. However, astrocytes and microglia were smaller after pre-traumatic microbiome depletion compared to vehicle treatment at 72 hpi, indicating less inflammatory activation. Accordingly, TBI-induced gene expression of the inflammation markers Interleukin-1ß, complement component C3, translocator protein TSPO and the major histocompatibility complex MHC2 was attenuated in microbiome-depleted mice along with reduced Immunoglobulin G extravasation as a proxy of blood-brain barrier (BBB) impairment. These results suggest that the gut microbiome contributes to early neuroinflammatory responses to TBI but does not have a significant impact on brain histopathology and neurological deficits. This article is part of the Special Issue on "Microbiome & the Brain: Mechanisms & Maladies".

Short and Concise Peer-to-Peer Teaching-Example of a Successful Antibiotic Stewardship Intervention to Increase Iv to Po Conversion.

Antibiotic stewardship (ABS) programs aim to combine effective treatment with minimized antibiotic-related harms. Common ABS interventions are simple and effective, but their implementation in daily practice is often difficult. The aim of our study was to investigate if a single, short, peer-to-peer teaching intervention (junior doctor to junior doctor) during clinical routine can successfully improve antibiotic prescriptions. We performed a quasi-experimental before-after study on a regular care cardiology ward at a large academic medical center in Germany. We evaluated antibiotic use metrics retrospectively and calculated defined daily doses (DDD) with the anatomical therapeutic chemical/DDD classification system of the World Health Organization. We hypothesize that the over-representative use of intravenous administration is a potentially modifiable target, which can be proven by antibiotic use metrics analysis. After a single peer-to-peer teaching session with a focus on indications for iv to po conversion, the normalized percentage of intravenous compared to oral administration significantly decreased (from 86.5 ± 50.3% to 41.4 ± 70.3%). Moreover, after the intervention, antibiotics with high oral bioavailability were no longer administered intravenously at all during the following quarter. Our results indicate that even a single peer-to-peer training session is highly effective in improving the iv to po conversion rate in the short term.

Lactococcus garvieae Endocarditis in a Prosthetic Aortic Valve: A Case Report and Literature Review.

BACKGROUND: Lactococcus garvieae (LG) is a gram-positive coccus known to be a major pathogen in aqua farming, which is responsible for severe outbreaks. Its incidence in humans is extremely rare. Prior to 1985, all bacteria in the genus Lactococcus were included in the Streptococcus genus. The first human infection was documented in 1991, and since then, the relevance and clinical significance in humans has increased. CASE DESCRIPTION: We present the clinical course of an LG endocarditis in a 78-year-old man who had a history of exertional dyspnea. The patient's blood tests showed increased inflammation values, and a transesophageal ultrasound (TEE) showed a stenosis of the prosthetic aortic valve. Blood cultures were positive for LG, leading to a diagnosis of infective endocarditis. After 6 weeks of intravenous antibiotics and a prosthetic aortic valve replacement, the patient made a good recovery. REVIEW OF THE LITERATURE: After the first documented case in 1991 to 2018, 25 cases of LG endocarditis have been described in PubMed and MEDLINE. We reviewed all reported cases of LG endocarditis, commenting on predisposing risk factors, the course and outcome of the disease. CONCLUSION: LG endocarditis is a rare disease. Consumption of raw fish, abnormalities of the digestive tract, immune deficiency, and underlying cardiac conditions appear to be risk factors for an infective endocarditis due to LG. Improved determination techniques are likely to lead to a better and faster identification of the bacterium. This identification allows a faster and individualized therapy, which in turn affects the outcome.

Hand hygiene in medical students: performance, education and knowledge.

BACKGROUND: Despite several guidelines on hand hygiene (HH), compliance especially in physicians is reported to be low which has huge implications for healthcare-associated infections. To evaluate performance of HH, influence of teaching and influence of monitoring the results in medical students, we conducted an observational study. METHODS: Performance of hand disinfection was evaluated in first (N=28), third (N=193) and fifth (N=45) year medical students using fluorescent hand disinfectant. The influence of teaching and information about result control was assessed. The students perception of the impact of HH was also evaluated by a questionnaire. RESULTS: Presence of disinfectant gaps was observed significantly more often in first year medical students compared to third year ones (82% vs, 60%; p=0.02). In additional, > 3 gaps were seen significantly more often in first year medical students compared to fifth year students (36% vs. 9%; p=0.007). Both information about teaching and monitoring the results improved outcome significantly. For example, gaps were present in 92% without information and without teaching, in 70% (RR: 1.3 (1.0-1.6); p=0.003) with information about result control only, and in only 18% (5.1 (3.0-8.5); p=0.0001) after teaching. Notably, the medical students ascribed HH to be of a great importance regardless of their level of education. CONCLUSIONS: Performance of HH could be improved by practical training as evidenced by best HH performance being documented immediately after teaching and a training effect during the course of medical studies was also observed. Thus, we suggest implementing regular education and practical training on HH from early on in the medical studies curricula to improve overall quality of patient care. regular education and practical training on HH from early on in the medical studies curricula to improve overall quality of patient care.

Hand hygiene in pediatric and neonatal intensive care unit patients: daily opportunities and indication- and profession-specific analyses of compliance.

BACKGROUND: Hand hygiene is considered to be the single most effective tool to prevent health care-associated infections. Daily hand hygiene opportunities and compliance for pediatric/neonatal intensive care units (ICU) are currently unknown. METHODS: This was a prospective observational study in pediatric and neonatal ICU patients with analyses of hand hygiene behavior in relation to profession, indication, and shift and correlation with disinfectant usage. RESULTS: Hand hygiene opportunities were significantly higher for pediatric (321/24 hours) than neonatal (194/24 hours; P = .024) patients. Observed compliance rates were 53% (pediatric) and 61% (neonatal) and found to be significantly higher in nurses (57%; 66%) than in physicians (29%, 52%, respectively; P < .001; P = .017, respectively). For neonates, compliance rates were significantly higher before patient contact and aseptic tasks (78%) than after patient, patient body fluid, or patients' surrounding contact (57%; P < .001). Calculating disinfectant usage revealed a 3-fold lower compliance rate of 17%. CONCLUSION: This study provides the first data on opportunities for and compliance with hand hygiene in pediatric/neonatal patients encompassing the whole day and night activities and including a comparison of observed and calculated compliance rates. Observation revealed high compliance especially in nurses and in situations of greatest impact. The data provide a detailed characterization of hand hygiene performance in the neonatal/pediatric ICU setting.

Compliance with hand hygiene on surgical, medical, and neurologic intensive care units: direct observation versus calculated disinfectant usage.

BACKGROUND: Hand hygiene (HH) is considered the single most effective measure to prevent and control health care-associated infections (HAIs). Although there have been several reports on compliance rates (CRs) to HH recommendations, data for intensive care units (ICUs) in general and for shift- and indication-specific opportunities in particular are scarce. METHODS: The aim of this study was to collect data on ICU-, shift-, and indication-specific opportunities, activities and CRs at a surgical ICU (SICU), a medical ICU (MICU), and a neurologic ICU (NICU) at the University Hospital Aachen based on direct observation (DO) and calculated disinfectant usage (DU). RESULTS: Opportunities for HH recorded over a 24-hour period were significantly higher for the SICU (188 per patient day [PD]) and MICU (163 per PD) than for the NICU (124 per PD). Directly observed CRs were 39% (73/188) in the SICU, 72% (117/163) in the MICU, and 73% (90/124) in the NICU. However, CRs calculated as a measure of DU were considerably lower: 16% (29/188) in the SICU, 21% (34/163) in the MICU, and 25% (31/124) in the NICU. Notably, CRs calculated from DO were lowest before aseptic tasks and before patient contact. CONCLUSIONS: To the best of our knowledge, this study provides the first data picturing a complete day, including shift- and indication-specific analyses, and comparing directly observed CRs with those calculated based on DU, the latter of which revealed a 2.75-fold difference. Worrisomely, CRs were very low, especially concerning indications of greatest impact in preventing HAIs, such as before aseptic task. Thus, the gathering of additional data on CRs and the reasons for noncompliance is warranted.