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Purpose of reviewThis review aims to provide an overview of the current knowledge about microbiota-targeted therapies in sepsis, and calls out - despite recent negative studies - not to halt our efforts of translating these tools into regular medical practice.Recent findingsThe intestinal microbiome has an important role in shaping our immune system, and microbiota-derived metabolites prime innate and adaptive inflammatory responses to infectious pathogens. Microbiota composition is severely disrupted during sepsis, which has been linked to increased risk of mortality and secondary infections. However, efforts of using these microbes as a tool for prognostic or therapeutic purposes have been unsuccessful so far, and recent trials studying the impact of probiotics in critical illness did not improve patient outcomes. Despite these negative results, researchers must continue their attempts of harnessing the microbiome to improve sepsis survival in patients with a high risk of clinical deterioration. Promising research avenues that could potentially benefit sepsis patients include the development of next-generation probiotics, use of the microbiome as a theranostic tool to direct therapy, and addressing the restoration of microbial communities following ICU discharge.SummaryAlthough research focused on microbiome-mediated therapy in critically ill patients has not yielded the results that were anticipated, we should not abandon our efforts to translate promising preclinical findings into clinical practice.

Background: Viruses and bacteria from the nasopharynx are capable of causing community-acquired pneumonia (CAP), which can be difficult to diagnose. We aimed to investigate whether shifts in the composition of these nasopharyngeal microbial communities can be used as diagnostic biomarkers for CAP in adults., Methods: We collected nasopharyngeal swabs from adult CAP patients and controls without infection in a prospective multicenter case-control study design. We generated bacterial and viral profiles using 16S ribosomal RNA gene sequencing and multiplex polymerase chain reaction (PCR), respectively. Bacterial, viral, and clinical data were subsequently used as inputs for extremely randomized trees classification models aiming to distinguish subjects with CAP from healthy controls., Results: We enrolled 117 cases and 48 control subjects. Cases displayed significant beta diversity differences in nasopharyngeal microbiota (P = .016, R2 = .01) compared to healthy controls. Our extremely randomized trees classification models accurately discriminated CAP caused by bacteria (area under the curve [AUC] .83), viruses (AUC .95) or mixed origin (AUC .81) from healthy control subjects. We validated this approach using a dataset of nasopharyngeal samples from 140 influenza patients and 38 controls, which yielded highly accurate (AUC .93) separation between cases and controls., Conclusions: Relative proportions of different bacteria and viruses in the nasopharynx can be leveraged to diagnose CAP and identify etiologic agent(s) in adult patients. Such data can inform the development of a microbiota-based diagnostic panel used to identify CAP patients and causative agents from nasopharyngeal samples, potentially improving diagnostic specificity, efficiency, and antimicrobial stewardship practices., peer-reviewed

Purpose of review This review summarizes recent progress in our understanding of the role of the gut microbiota in sepsis pathogenesis and outlines the potential role of microbiota-targeted therapies. Recent findings The composition of the gut microbiome is profoundly distorted during sepsis, with a loss of commensal bacteria and an overgrowth of potential pathogenic micro-organisms. These alterations also extend to nonbacterial intestinal inhabitants. Disruptions of these intestinal communities are associated with both an increased susceptibility to develop sepsis, as well as a higher risk of adverse outcomes. Preclinical studies have characterized the effects of several microbiota-derived metabolites (such as D-lactate, butyrate, and deoxycholic acid) on enhancing the host immune response during critical illness. Microbiota-targeted therapies (e.g. probiotics or fecal microbiota transplantation) might be of benefit, but can also be associated with increased risks of bloodstream infections. Summary Emerging evidence display an important role of gut micro-organisms (including bacteria, fungi, eukaryotic viruses, and bacteriophages) and their derived metabolites in both the susceptibility to, as well as outcomes of sepsis. Despite recent progress in the mechanistic understanding of microbiota-mediated protection, clinical breakthroughs in the development of microbiota-based prognostic tools or therapies are thus far lacking in the field of sepsis.

Background Strongly elevated ferritin levels have been proposed to reflect systemic hyperinflammation in patients admitted to the intensive care unit. Knowledge of the incidence and pathophysiological implications of hyperferritinemia in patients with acute infection admitted to a non–intensive care setting is limited. Methods We determined the association between hyperferritinemia, defined by 2 cutoff values (500 and 250 ng/mL), and aberrations in key host response mechanisms among patients with community-acquired pneumonia (CAP) on admission to a general hospital ward (clinicaltrials.gov NCT02928367; trialregister.nl NTR6163). Results Plasma ferritin levels were higher in patients with CAP (n = 174; median [interquartile ranges], 259.5 [123.1–518.3] ng/mL) than in age- and sex-matched controls without infection (n = 50; 102.8 [53.5–185.7] ng/mL); P Conclusions Hyperferritinemia identifies patients with CAP with a broad deregulation of various host response mechanisms implicated in the pathogenesis of sepsis. This could inform future therapeutic strategies targeting subgroups within the CAP population.

We report a case of an immune reconstitution inflammatory syndrome induced by gluteal silicones in a transgender woman living with HIV following the start of antiretroviral therapy. This case resembles the autoimmune/inflammatory syndrome induced by adjuvants (ASIA) syndrome that has been described as a complication of insertions of materials such as injected or implanted silicones. The potential of developing an inflammatory response in patient with injected or implanted silicones/foreign substances should be considered in patients who have recently started antiretroviral therapy.

BackgroundThe microbiome has emerged as an important player in the pathophysiology of a whole spectrum of diseases that affect the critically ill. We hypothesized that differences in microbiota composition across vendors can influence murine models of pulmonary lipopolysaccharide (LPS) inflammation and Gram-negative pneumonia.MethodsA multi-vendor approach was used with genetically similar mice derived from three different vendors (Janvier, Envigo, Charles River). This model was employed to study the effect on the host response to a pulmonary LPS challenge (1 μgKlebsiella pneumoniaeLPS, intranasal), as well as experimentalK. pneumoniaeinfection (ATCC43816,1 × 104CFU, intranasal).ResultsGut microbiota analysis revealed profound intervendor differences in bacterial composition as shown by beta diversity and at various taxonomic levels. Tumor necrosis factor (TNF)-α and interleukin (IL)-6 release in lung and bronchoalveolar lavage fluid (BALF) were determined 6 and 24 h after intranasal treatment with LPS. No differences were found between the groups, with the exception for Envigo, showing a higher level of TNFα in lung and BALF at 6 h compared to Janvier and Charles River. In another set of experiments, mice from different vendors were subjected to a clinically relevant model of Gram-negative pneumonia (K. pneumoniae). At 12 and 36 h post-infection, no intervendor differences were found in bacterial dissemination, or TNFα and IL-6 levels in the lungs. In line, markers for organ failure did not differ between groups.ConclusionsAlthough there was a marked variation in the gut microbiota composition of mice from different vendors, the hypothesized impact on our models of pulmonary inflammation and severe pneumonia was limited. This is of significance for experimental settings, showing that differences in gut microbiota do not have to lead to differences in outcome.

Background: The plasticity of monocytes enables them to exert multiple roles during an immune response, including promoting immune tolerance. How monocytes alter their functions to convey immune tolerance in the context of lower respiratory tract infections in humans is not well understood. Here, we sought to identify epigenetic and transcriptomic features of cytokine production capacity in circulating monocytes during community-acquired pneumonia (CAP)., Methods: Circulating CD14+ monocytes were obtained from the blood of CAP patients included in a longitudinal, observational cohort study, on hospitalization (acute stage, n=75), and from the same patients after a 1-month follow-up (recovery stage, n=56). Age and sex-matched non-infectious participants were included as controls (n=41). Ex vivo cytokine production after lipopolysaccharide (LPS) exposure was assessed by multiplex assay. Transcriptomes of circulating monocytes were generated by RNA-sequencing, and DNA methylation levels in the same monocytes were measured by reduced representation bisulfite sequencing. Data were integrated by fitting projection-to-latent-structure models, and signatures derived by partial least squares discrimination., Results: Monocytes captured during the acute stage exhibited impaired TNF, IL-1β, IL-6, and IL-10 production after ex vivo stimulation with LPS, relative to controls. IL-6 production was not resolved in recovery monocytes. Multivariate analysis of RNA-sequencing data identified 2938 significantly altered RNA transcripts in acute-stage monocytes (fold expression ≤-1.5 or ≥1.5; adjusted p ≤ 0.01), relative to controls. Comparing DNA methylation levels in circulating monocytes of CAP patients to controls revealed minimal differences, specifically in DNAse hypersensitive sites (HS) of acute-stage monocytes. Data integration identified a cholesterol biosynthesis gene signature and DNAse HS axis of IL-1β and IL-10 production (R2 =0.51)., Conclusions: Circulating monocytes obtained from CAP patients during the acute stage exhibited impaired cytokine production capacities, indicative of reprogramming to a state of immune tolerance, which was not fully resolved after 1 month. Our split-sample study showed that 51% of the immune tolerance phenotype can be explained, at least in part, by coordinated shifts in cholesterol biosynthesis gene expression and DNAse HS methylation levels. A multi-scale model identified an epigenetic and transcriptomic signature of immune tolerance in monocytes, with implications for future interventions in immunosuppression., peer-reviewed

Background: Bacterial intestinal communities interact with the immune system and may contribute to protection against community-acquired pneumonia (CAP). Intestinal viruses are closely integrated with these bacterial communities, yet the composition and clinical significance of these communities in CAP patients are unknown. The aims of this exploratory study were to characterise the composition of the rectal bacteriome and virome at hospital admission for CAP, and to determine if microbiota signatures correlate with clinical outcomes., Methods: We performed a prospective observational cohort study in CAP patients, admitted to a university or community hospital in the Netherlands between October 2016 and July 2018, and controls. Rectal bacteriome and virome composition were characterised using 16S ribosomal RNA gene sequencing and virus discovery next-generation sequencing, respectively. Unsupervised multi-omics factor analysis was used to assess the co-variation of bacterial and viral communities, which served as primary predictor. The clinical outcomes of interest were the time to clinical stability and the length of hospital stay., Findings: 64 patients and 38 controls were analysed. Rectal bacterial alpha (p = 0•0015) and beta diversity (r2 =0•023, p = 0•004) of CAP patients differed from controls. Bacterial and viral microbiota signatures correlated with the time to clinical stability (hazard ratio 0•43, 95% confidence interval 0•20-0•93, p = 0•032) and the length of hospital stay (hazard ratio 0•37, 95% confidence interval 0•17-0•81, p = 0•012), although only the latter remained significant following p-value adjustment for examining multiple candidate cut-points (p = 0•12 and p = 0•046, respectively)., Interpretation: This exploratory study provides preliminary evidence that intestinal bacteriome and virome signatures could be linked with clinical outcomes in CAP. Such exploratory data, when validated in independent cohorts, could inform the development of a microbiota-based diagnostic panel used to predict clinical outcomes in CAP., Funding Netherlands Organization for Scientific Research and Netherlands Organization for Health Research and Development., peer-reviewed

Combined culture-dependent and culture-independent metagenomic sequencing methods reveal the pervasive and long-lasting presence of antimicrobial resistance genes within a tertiary hospital environment.

OBJECTIVES: The impact of combination antibiotic therapy on the composition of the intestinal microbiota remains ill-defined. We aimed to assess the effect of a 1 week antibiotic regimen on the intestinal microbiota of healthy humans for a period of up to 31 months. PATIENTS AND METHODS: Thirteen healthy adult men received either no treatment or oral broad-spectrum antibiotics (ciprofloxacin, vancomycin and metronidazole) for 7 days. At four timepoints (prior to treatment, on day 9, day 49 and 8-31 months later) faecal samples were collected and analysed using 16S RNA gene sequencing. RESULTS: The short-term impact of broad-spectrum antibiotics on the gut microbiota was profound, with a loss of diversity and drastic shifts in community composition. In addition, antibiotics significantly reduced the abundance of bacterial taxa with important metabolic functions, such as the production of butyrate. The microbiota showed a remarkable return towards baseline after 8-31 months, but community composition often remained altered from its initial state. CONCLUSIONS: These findings suggest that combined treatment with vancomycin, ciprofloxacin and metronidazole has a profound and long-lasting effect on microbiota composition, the consequences of which remain largely unknown.

Although the pathophysiology of asthma is complex, perturbation of the gut microbiota has been associated with an increased risk of asthma development in childhood.1 Disruption and subsequent dysregulation of gut microbiota-related immunologic processes have also been linked to disease severity and response to treatment.2.

cited By 2 Bacterial microbiota play a critical role in mediating local and systemic immunity, and shifts in these microbial communities have been linked to impaired outcomes in critical illness. Emerging data indicate that other intestinal organisms, including bacteriophages, viruses of eukaryotes, fungi, and protozoa, are closely interlinked with the bacterial microbiota and their host, yet their collective role during antibiotic perturbation and critical illness remains to be elucidated. We employed multi-omics factor analysis (MOFA) to systematically integrate the bacterial (16S rRNA), fungal (intergenic transcribed spacer 1 rRNA), and viral (virus discovery next generation sequencing) components of the intestinal microbiota of 33 critically ill patients with and without sepsis and 13 healthy volunteers. In addition, we quantified the absolute abundances of bacteria and fungi using 16S and 18S rRNA PCRs and characterized the short-chain fatty acids (SCFAs) butyrate, acetate, and propionate using nuclear magnetic resonance spectroscopy. We observe that a loss of the anaerobic intestinal environment is directly correlated with an overgrowth of aerobic pathobionts and their corresponding bacteriophages as well as an absolute enrichment of opportunistic yeasts capable of causing invasive disease. We also observed a strong depletion of SCFAs in both disease states, which was associated with an increased absolute abundance of fungi with respect to bacteria. Therefore, these findings illustrate the complexity of transkingdom changes following disruption of the intestinal bacterial microbiome. IMPORTANCE While numerous studies have characterized antibiotic-induced disruptions of the bacterial microbiome, few studies describe how these disruptions impact the composition of other kingdoms such as viruses, fungi, and protozoa. To address this knowledge gap, we employed MOFA to systematically integrate viral, fungal, and bacterial sequence data from critically ill patients (with and without sepsis) and healthy volunteers, both prior to and following exposure to broad-spectrum antibiotics. In doing so, we show that modulation of the bacterial component of the microbiome has implications extending beyond this kingdom alone, enabling the overgrowth of potentially invasive fungi and viruses. While numerous preclinical studies have described similar findings in vitro, we confirm these observations in humans using an integrative analytic approach. These findings underscore the potential value of multi-omics data integration tools in interrogating how different components of the microbiota contribute to disease states. In addition, our findings suggest that there is value in further studying potential adjunctive therapies using anaerobic bacteria or SCFAs to reduce fungal expansion after antibiotic exposure, which could ultimately lead to improved outcomes in the intensive care unit (ICU).

In recent years, preclinical studies have illustrated the potential role of intestinal bacterial composition in the risk of stroke and post-stroke infections. The results of these studies suggest that bacteria capable of producing volatile metabolites, including trimethylamine-N-oxide (TMAO) and butyrate, play opposing, yet important roles in the cascade of events leading to stroke. However, no large-scale studies have been undertaken to determine the abundance of these bacterial communities in stroke patients and to assess the impact of disrupted compositions of the intestinal microbiota on patient outcomes. In this prospective case–control study, rectal swabs from 349 ischemic and hemorrhagic stroke patients (median age, 71 years; IQR: 67–75) were collected within 24 h of hospital admission. Samples were subjected to 16S rRNA amplicon sequencing and subsequently compared with samples obtained from 51 outpatient age- and sex-matched controls (median age, 72 years; IQR, 62–80) with similar cardiovascular risk profiles but without active signs of stroke. Plasma protein biomarkers were analyzed using a combination of nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography–mass spectrometry (LC-MS). Alpha and beta diversity analyses revealed higher disruption of intestinal communities during ischemic and hemorrhagic stroke compared with non-stroke matched control subjects. Additionally, we observed an enrichment of bacteria implicated in TMAO production and a loss of butyrate-producing bacteria. Stroke patients displayed two-fold lower plasma levels of TMAO than controls (median 1.97 vs 4.03 μM, Wilcoxon p

Background: Dysregulation of the host immune response is a pathognomonic feature of sepsis. Abnormal physiological conditions are understood to shift efficient linear splicing of protein-coding RNA towards non-canonical splicing, characterized by the accumulation of non-coding circularized (circ)RNA. CircRNAs remain unexplored in specific peripheral blood mononuclear cells (PBMCs) during sepsis. We here sought to identify and characterize circRNA expression in specific PBMCs of patients with sepsis due to community-acquired pneumonia (CAP) relative to healthy subjects. Methods: The study comprised a discovery cohort of six critically ill patients diagnosed with sepsis due to community-acquired pneumonia and four (age, gender matched) healthy subjects. PBMCs were isolated, and fluorescence-activated cell sorting was used to purify CD14+ monocytes, CD4+, CD8+ T cells, and CD19+ B cells for RNA sequencing. CD14+ monocytes from independent six healthy volunteers were purified, and total RNA was treated with or without RNase R. Results: RNA sequencing of sorted CD14+ monocytes, CD4+, CD8+ T cells, and CD19+ B cells from CAP patients and healthy subjects identified various circRNAs with predominantly cell-specific expression patterns. CircRNAs were expressed to a larger extent in monocytes than in CD4+, CD8+ T cells, or B cells. Cells from CAP patients produced significantly higher levels of circRNA as compared to healthy subjects. Considering adjusted p values, circVCAN (chr5:83519349-83522309) and circCHD2 (chr15:93000512-93014909) levels in monocytes were significantly altered in sepsis. Functional inference per cell-type uncovered pathways mainly attuned to cell proliferation and cytokine production. In addition, our data does not support a role for these circRNAs in microRNA sequestration. Quantitative PCR analysis in purified monocytes from an independent group of healthy volunteers confirmed the existence of circVCAN and circCHD2. Conclusions: We provide a benchmark map of circRNA expression dynamics in specific immune cell subsets of sepsis patients secondary to CAP. CircRNAs were more abundant in immune cells of sepsis patients relative to healthy subjects. Further studies evaluating circRNA expression in larger cohorts of sepsis patients are warranted., peer-reviewed

Background Experimental murine models and human challenge studies of Salmonella Typhi infection have suggested that the gut microbiome plays an important protective role against the development of typhoid fever. Anaerobic bacterial communities have been hypothesized to mediate colonization resistance against Salmonella species by producing short-chain fatty acids, yet the composition and function of the intestinal microbiota in human patients with typhoid fever remain ill defined. Methods We prospectively collected fecal samples from 60 febrile patients admitted to Chittagong Medical College Hospital, Bangladesh, with typhoid fever or nontyphoidal febrile illness and from 36 healthy age-matched controls. The collected fecal samples were subjected to 16s rRNA sequencing followed by targeted metabolomics analysis. Results Patients with typhoid fever displayed compositional and functional disruption of the gut microbiota compared with patients with nontyphoidal febrile illness and healthy controls. Specifically, typhoid fever patients had lower microbiota richness and alpha diversity and a higher prevalence of potentially pathogenic bacterial taxa. In addition, a lower abundance of short-chain fatty acid–producing taxa was seen in typhoid fever patients. The differences between typhoid fever and nontyphoidal febrile illness could not be explained by a loss of colonization resistance after antibiotic treatment, as antibiotic exposure in both groups was similar. Conclusions his first report on the composition and function of the gut microbiota in patients with typhoid fever suggests that the restoration of these intestinal commensal microorganisms could be targeted using adjunctive, preventive, or therapeutic strategies.

Bacterial microbiota play a critical role in mediating local and systemic immunity, and shifts in these microbial communities have been linked to impaired outcomes in critical illness. Emerging data indicate that other intestinal organisms, including bacteriophages, viruses of eukaryotes, fungi, and protozoa, are closely interlinked with the bacterial microbiota and their host, yet their collective role during antibiotic perturbation and critical illness remains to be elucidated. Here, multi-omics factor analysis (MOFA), a novel computational strategy to systematically integrate viral, fungal and bacterial sequence data, we describe the functional impact of exposure to broad-spectrum antibiotics in healthy volunteers and critically ill patients. We observe that a loss of the anaerobic intestinal environment is directly correlated with an overgrowth of aerobic pathobionts and their corresponding bacteriophages, as well as an absolute enrichment of opportunistic yeasts capable of causing invasive disease. These findings further illustrate the complexity of transkingdom interactions within the intestinal environment, and show that modulation of the bacterial component of the microbiome has implications extending beyond this kingdom alone.

New findings regarding the risks of over-the-counter probiotics in critically ill patients underscore the need for microbiota-targeted therapies that are based on efficacy in a disease- and host-specific context.

Respiratory viral infections are frequent in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HCT) and can potentially progress to lower respiratory tract infection (LRTI). The intestinal microbiota contributes to resistance against viral and bacterial pathogens in the lung. However, whether intestinal microbiota composition and associated changes in microbe-derived metabolites contribute to the risk of LRTI following upper respiratory tract viral infection remains unexplored in the setting of allo-HCT. Fecal samples from 360 allo-HCT patients were collected at the time of stem cell engraftment and subjected to deep, 16S ribosomal RNA gene sequencing to determine microbiota composition, and short-chain fatty acid levels were determined in a nested subset of fecal samples. The development of respiratory viral infections and LRTI was determined for 180 days following allo-HCT. Clinical and microbiota risk factors for LRTI were subsequently evaluated using survival analysis. Respiratory viral infection occurred in 149 (41.4%) patients. Of those, 47 (31.5%) developed LRTI. Patients with higher abundances of butyrate-producing bacteria were fivefold less likely to develop viral LRTI, independent of other factors (adjusted hazard ratio = 0.22, 95% confidence interval 0.04-0.69). Higher representation of butyrate-producing bacteria in the fecal microbiota is associated with increased resistance against respiratory viral infection with LRTI in allo-HCT patients.

Rotavirus vaccines (RVV) protect against childhood gastroenteritis caused by rotavirus (RV) but have decreased effectiveness in low- and middle-income settings. This proof-of-concept, randomized-controlled, open-label trial tested if microbiome modulation can improve RVV immunogenicity. Healthy adults were randomized and administered broad-spectrum (oral vancomycin, ciprofloxacin, metronidazole), narrow-spectrum (vancomycin), or no antibiotics and then vaccinated with RVV, 21 per group per protocol. Baseline anti-RV IgA was high in all subjects. Although antibiotics did not alter absolute anti-RV IgA titers, RVV immunogenicity was boosted at 7 days in the narrow-spectrum group. Further, antibiotics increased fecal shedding of RV while also rapidly altering gut bacterial beta diversity. Beta diversity associated with RVV immunogenicity boosting at day 7 and specific bacterial taxa that distinguish RVV boosters and RV shedders were identified. Despite the negative primary endpoint, this study demonstrates that microbiota modification alters the immune response to RVV and supports further exploration of microbiome manipulation to improve RVV immunogenicity. Rotavirus vaccines (RVV) are less effective in poor-resourced settings. This randomized-controlled trial in adults tested the effect of microbiome modulation via broad-spectrum, narrow-spectrum, or no antibiotics on RVV performance. Absolute anti-RV IgA titer did not change. However, antibiotics resulted in higher day-7 boosting and increased RV-antigen shedding.

Purpose of reviewThe review aims to discuss emerging evidence in the field of microbiome-dependent roles in host defense during critical illness with a focus on lung, kidney, and brain inflammation.Recent findingsThe gut microbiota of critical ill patients is characterized by lower diversity, lower abundances of key commensal genera, and in some cases overgrowth by one bacterial genera, a state otherwise known as dysbiosis. Increasing evidence suggests that microbiota-derived components can reach the circulatory system from the gut and modulate immune homeostasis. Dysbiosis might have greater consequences for the critically ill than previously imagined and could contribute to poor outcome. Preclinical studies suggest that impaired communication across the gut - organ axes is associated with brain, lung - and kidney failure.SummaryIn health, a diverse microbiome might enhance host defense, while during critical illness, the dysbiotic microbiome might contribute to comorbidity and organ dysfunction. Future research should be aimed at further establishing the causes and consequences of dysbiosis seen in the critically ill, which will provide perspective for developing new strategies of intervention

Melioidosis is a severe infectious disease with a high mortality that is endemic in South-East Asia and Northern Australia. The causative pathogen, Burkholderia pseudomallei, is listed as potential bioterror weapon due to its high virulence and potential for easy dissemination. Currently, there is no licensed vaccine for prevention of melioidosis. Here, we explore the use of rapid plasmid DNA vaccination against B. pseudomallei flagellin for protection against respiratory challenge. We tested three flagellin DNA vaccines with different subcellular targeting designs. C57BL/6 mice were vaccinated via skin tattoo on day 0, 3 and 6 before intranasal challenge with B. pseudomallei on day 21. Next, the most effective construct was used as single vaccination on day 0 by tattoo or intranasal formulation. Mice were sacrificed 72 hours post-challenge to assess bacterial loads, cytokine responses, inflammation and microscopic lesions. A construct encoding a cellular secretion signal resulted in the most effective protection against melioidosis via tattooing, with a 10-fold reduction in bacterial loads in lungs and distant organs compared to the empty vector. Strikingly, a single intranasal administration of the same vaccine resulted in >1000-fold lower bacterial loads and increased survival. Pro-inflammatory cytokine responses were significantly diminished and strong reductions in markers for distant organ damage were observed. A rapid vaccination scheme using flagellin DNA tattoo provides significant protection against intranasal challenge with B. pseudomallei, markedly improved by a single administration via airway mucosa. Hence intranasal vaccination with flagellin-encoding DNA may be applicable when acute mass vaccination is indicated and warrants further testing.

Purpose of review The composition and diversity of the microbiota of the human gut, skin, and several other sites is severely deranged in critically ill patients on the ICU, and it is likely that these disruptions can negatively affect outcome. We here review new and ongoing studies that investigate the use of microbiota- targeted therapeutics in the ICU, and provide recommendations for future research. Recent findings Practically every intervention in the ICU as well as the physiological effects of critical illness itself can have a profound impact on the gut microbiota. Therapeutic modulation of the microbiota, aimed at restoring the balance between ` pathogenic' and ` health- promoting' microbes is therefore of significant interest. Probiotics have shown to be effective in the treatment of ventilator- associated pneumonia, and the first fecal microbiota transplantations have recently been safely and successfully performed in the ICU. However, allencompassing data in this vulnerable patient group remain sparse, and only a handful of novel studies that study microbiota- targeted therapies in the ICU are currently ongoing. Summary Enormous strides have been made in characterizing the gut microbiome of critically ill patients in the ICU, and an increasing amount of preclinical data reveals the huge potential of microbiota- targeted therapies. Further understanding of the causes and consequences of dysbiosis on ICU- related outcomes are warranted to push the field forward

The field of infectious disease is undergoing a paradigm shift as the intestinal microbiome is becoming understood. The aim of this review is to inform infectious disease physicians of the potential relevance of the intestinal microbiome to their practice. We searched Medline using both index and text words relating to infectious diseases, microbiome, and probiotics. Relevant articles published up through 2017 were reviewed within Rayyan. The review illustrates pathophysiologic concepts linking the microbiome and infectious diseases; specifically, the intestinal microbiome’s relevance to early immune development, the microbiome and enteric infections, the microbiome’s relevance in compromised hosts, and antimicrobial resistance. Within each subject, there are specific examples of diseases and at-risk patient populations where a role for the microbiome has been strongly established. This provides an overview of the significance of the intestinal microbiome to microbiology, pediatric and adult infectious diseases with an underpinning of concepts useful for the practicing clinician.

Summary For decades, the gut was thought to play an important role in sepsis pathogenesis. Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Organ failure assessment for sepsis focuses on respiratory, cardiovascular, hepatic, renal, neurological, and haematological systems. Unfortunately, symptoms of gut failure are non-specific and are therefore not assessed. The composition of the intestinal microbiome, however, is affected by sepsis, and might contribute to the development of organ failure. Experimental work underscores the role of the microbiota in maintaining gut-barrier function, and modulation of the innate and adaptive immune system. Translation of these preclinical findings into functional characterisations will be essential to understand how disruption of commensals affects susceptibility and outcome of sepsis. In this Review, we identify knowledge gaps which, if addressed, will help researchers understand the role of the microbiota in sepsis, and provide microbiota-targeted tools to improve sepsis management.

Obesity is a major health concern not only in the general population but also in patients with haemophilia. Little is known about the consequences of obesity for haemophilia patients. As obesity is an important risk factor for osteoarthritis, these effects may be even more pronounced in haemophilia patients who are prone to joint damage. The association between obesity and limitations in daily activities as well as the frequency of bleeds and use of factor VIII (FVIII) concentrate in obese and normal weight haemophilia patients was assessed. Fifteen obese (BMI ≥ 30 kg m(-2)) and fifteen normal weight (BMI ≤ 25 kg m(-2)) haemophilia A patients matched for severity and age were analysed. The Hemophilia Activities List (HAL) was used to assess the impairment in daily activities. Compared with the normal weight haemophilia patients, obese haemophiliacs had a significantly lower sum score (88/100 and 98/100, respectively, P = 0.02), which was mainly caused by an impaired lower limb function. All other components of the HAL also showed lower scores in the obese patients, but did not reach statistical significance. A higher frequency of bleeds requiring treatment with FVIII concentrate occurred in the obese haemophiliacs (17 bleeds in eight individuals) compared with the controls (three bleeds in three individuals) (P = 0.045). Compared with non-obese haemophilia patients, obese haemophiliacs had more joint bleeds and a lower overall HAL score, which was driven by a lower limb function score. Prevention of overweight and weight reduction requires special attention from physicians treating haemophilia patients.

INTRODUCTIONMidgut volvulus due to intestinal malrotation is a rare cause of intestinal obstruction when occurring in adult life. This paper documents the difficulties in reaching an early diagnosis.PRESENTATION OF CASEWe describe the case of an 85-year-old man with non-specific abdominal complaints for 20 years, who presented with sudden onset central abdominal pain. An acute median laparotomy under general anaesthesia was performed during which a 360° clockwise rotation of the small bowel around the mesenteric pedicle of the superior mesenteric artery and vein was found.DISCUSSIONMalrotation is considered any deviation of the normal rotation of the midgut in embryological development, causing intermittent episodes of gastrointestinal obstruction or acute events of midgut volvulus. Although mainly a paediatric diagnosis, some cases do present in adult life. Radiologic investigations include: upper gastrointestinal contrast studies, Doppler sonography and a contrast enhanced CT of the abdomen. If a true malrotation is diagnosed or found by coincidence, a Ladd's procedure is advised, even if the patient is asymptomatic. There is no proven surgical strategy for preventing the recurrence of small bowel volvulus in case of malfixation of the midgut.CONCLUSIONNon-specific recurrent abdominal complaints in adults of any age should raise suspicion of the possibility of a midgut malrotation or malfixation with or without intermittent volvulus. This case highlights the importance of diagnosis in an early stage.

See also Makris M, van Veen JJ. Reduced cardiovascular mortality in hemophilia despite normal atherosclerotic load. This issue, pp 20–2; Zwiers M, Lefrandt JD, Mulder DJ, Smit AJ, Gans ROB, Vliegenthart R, Brands-Nijenhuis AVM, Kluin-Nelemans JC, Meijer K. Coronary artery calcification score and carotid intima–media thickness in patients with hemophilia. This issue, pp 23–9. Summary. Background: Hemophilia A patients have a lower cardiovascular mortality rate than the general population. Whether this protection is caused by hypocoagulability or decreased atherogenesis is unclear. Objectives: To evaluate atherosclerosis and endothelial function in hemophilia A patients with and without obesity as well as in matched, unaffected controls. Methods: Fifty-one obese (body mass index [BMI] ≥ 30 kg m−2) and 47 non-obese (BMI ≤ 25 kg m−2) hemophilia A patients, and 42 obese and 50 matched non-obese male controls were included. Carotid and femoral intima–media thickness [IMT] and brachial flow-mediated dilatation (FMD) were measured as markers of atherogenesis and endothelial function. Results: The overall population age was 50 ± 13 years. Carotid IMT was increased in obese subjects (0.77 ± 0.22 mm) as compared with non-obese subjects (0.69 ± 0.16 mm) [mean difference 0.07 mm (95% confidence interval [CI] 0.02–0.13, P = 0.008)]. No differences in mean carotid and femoral IMT between obese hemophilic patients and obese controls were found (mean difference of 0.02 mm [95% CI − 0.07–0.11, P = 0.67], and mean difference of 0.06 mm [95% CI − 0.13–0.25, P = 0.55], respectively). Thirty-five per cent of the obese hemophilic patients and 29% of the obese controls had an atherosclerotic plaque (P = 0.49), irrespective of the severity of hemophilia. Brachial FMD was comparable between obese hemophilic patients and obese controls (4.84% ± 3.24% and 5.32% ± 2.37%, P = 0.45). Conclusion: Hemophilia A patients with obesity develop atherosclerosis to a similar extent as the general male population. Detection and treatment of cardiovascular risk factors in hemophilic patients is equally necessary.