Sepsis In Pigs Research Articles

Evaluation of Glutathione (GSH) System in Porcine Saliva: Validation and Application of Colorimetric Method.

(1) Reduced glutathione (GSH) is considered the first line of antioxidant defense. During oxidative stress, it is oxidized to glutathione disulphide (GSSG). (2) A simple and quick spectrophotometric method based on sodium borohydride (NaBH4) as a reductant to measure the total and reduced GSH in porcine saliva was analytically validated and evaluated in two situations in this species: (a) in a physiological situation, involving sows during the late lactation and post-weaning periods, and (b) in a situation of sepsis in pigs experimentally induced by LPS administration. (3) The results of the analytical validation showed that the assay was precise and accurate in the porcine saliva samples. Higher total GSH and GSSG and lower reduced GSH were observed in the saliva of sows during the post-weaning period, as well as in pigs with experimentally induced sepsis. (4) In conclusion, the validated assay showed adequate analytical results and could be used to evaluate the GSH system of porcine saliva, as demonstrated during the clinical performance.

Muscle protein catabolism and splanchnic arginine consumption drive arginine dysregulation during Pseudomonas Aeruginosa induced early acute sepsis in swine.

Human sepsis is characterized by increased protein breakdown and changes in arginine and citrulline metabolism. However, it is unclear whether this is caused by changes in transorgan metabolism. We therefore studied in a Pseudomonas aeruginosa induced pig sepsis model the changes in protein and arginine related metabolism on whole body (Wb) and transorgan level. We studied 22 conscious pigs for 18 hours during sepsis, induced by infusing live bacteria (Pseudomonas aeruginosa) or after placebo infusion (control). We used stable isotope tracers to measure Wb and skeletal muscle protein synthesis and breakdown, as well as Wb, splanchnic, skeletal muscle, hepatic and portal drained viscera (PDV) arginine and citrulline disposal and production rates. During sepsis, arginine Wb production (p=0.0146), skeletal muscle release (p=0.0035) and liver arginine uptake were elevated (p=0.0031). Wb de novo arginine synthesis, citrulline production, and transorgan PDV release of citrulline, glutamine and arginine did not differ between sepsis and controls. However, Wb (p<0.0001) and muscle (p<0.001) protein breakdown were increased, suggesting that the enhanced arginine production is predominantly derived from muscle breakdown in sepsis. In conclusion, live-bacterium sepsis increases muscle arginine release and liver uptake, mirroring previous pig endotoxemia studies. In contrast to observations in humans, acute live-bacterium sepsis in pigs does not change citrulline production or arterial arginine concentration. We therefore conclude that the arginine dysregulation observed in human sepsis is possibly initiated by enhanced protein catabolism and splanchnic arginine catabolism, while decreased arterial arginine concentration and citrulline metabolism may require more time to fully manifest in patients.

Citrulline and ADI-PEG20 reduce inflammation in a juvenile porcine model of acute endotoxemia.

Arginine is a conditionally essential amino acid that is depleted in critically ill or surgical patients. In pediatric and adult patients, sepsis results in an arginine-deficient state, and the depletion of plasma arginine is associated with greater mortality. However, direct supplementation of arginine can result in the excessive production of nitric oxide (NO), which can contribute to the hypotension and macrovascular hypo-reactivity observed in septic shock. Pegylated arginine deiminase (ADI-PEG20, pegargiminase) reduces plasma arginine and generates citrulline that can be transported intracellularly to generate local arginine and NO, without resulting in hypotension, while maintaining microvascular patency. The objective of this study was to assess the efficacy of ADI-PEG20 with and without supplemental intravenous citrulline in mitigating hypovolemic shock, maintaining tissue levels of arginine, and reducing systemic inflammation in an endotoxemic pediatric pig model. Twenty 3-week-old crossbred piglets were implanted with jugular and carotid catheters as well as telemetry devices in the femoral artery to measure blood pressure, body temperature, heart rate, and respiration rate. The piglets were assigned to one of three treatments before undergoing a 5h lipopolysaccharide (LPS) infusion protocol. Twenty-four hours before LPS infusion, control pigs (LPS; n=6) received saline, ADI-PEG20 pigs (n=7) received an injection of ADI-PEG20, and seven pigs (ADI-PEG20 + CIT pigs [n=7]) received ADI-PEG20 and 250 mg/kg citrulline intravenously. Pigs were monitored throughout LPS infusion and tissue was harvested at the end of the protocol. Plasma arginine levels decreased and remained low in ADI-PEG20 + CIT and ADI-PEG20 pigs compared with LPS pigs but tissue arginine levels in the liver and kidney were similar across all treatments. Mean arterial pressure in all groups decreased from 90 mmHg to 60 mmHg within 1h of LPS infusion but there were no significant differences between treatment groups. ADI-PEG20 and ADI-PEG20 + CIT pigs had less CD45+ infiltrate in the liver and lung and lower levels of pro-inflammatory cytokines in the plasma. ADI-PEG20 and citrulline supplementation failed to ameliorate the hypotension associated with acute endotoxic sepsis in pigs but reduced systemic and local inflammation in the lung and liver.

Evaluating the Antibacterial and Antivirulence Activities of Floxuridine against Streptococcus suis.

Streptococcus suis is an emerging zoonotic pathogen that can cause fatal diseases such as meningitis and sepsis in pigs and human beings. The overuse of antibiotics is leading to an increased level of resistance in S. suis, and novel antimicrobial agents or anti-virulence agents for the treatment of infections caused by S. suis are urgently needed. In the present study, we investigated the antibacterial activity, mode of action and anti-virulence effects of floxuridine against S. suis. Floxuridine showed excessive antibacterial activity against S. suis both in vivo and in vitro; 4 × MIC of floxuridine could kill S. suis within 8 h in a time-kill assay. Meanwhile, floxuridine disrupted the membrane structure and permeability of the cytoplasmic membrane. Molecular docking revealed that floxuridine and SLY can be directly bind to each other. Moreover, floxuridine effectively inhibited the hemolytic capacity and expression levels of the virulence-related genes of S. suis. Collectively, these results indicate that the FDA-approved anticancer drug floxuridine is a promising agent and a potential virulence inhibitor against S. suis.

A Proteomic Approach to Elucidate the Changes in Saliva and Serum Proteins of Pigs with Septic and Non-Septic Inflammation

Sepsis is a systemic inflammatory response triggered by an infectious agent and is recognized by the World Health Organization as a global concern, since it is one of the major causes of severe illness in humans and animals. The study of the changes that can occur in saliva and serum in sepsis can contribute to a better understanding of the pathophysiological mechanisms involved in the process and also to discover potential biomarkers that can help in its diagnosis and monitoring. The objective of this study was to characterize the changes that occur in the salivary and serum proteome of pigs with experimentally-induced sepsis. The study included five pigs with sepsis induced by LPS administration and five pigs with non-septic inflammation induced by turpentine for comparative purposes. In saliva, there were eighteen salivary proteins differentially expressed in the sepsis condition and nine in non-septic inflammation. Among these, significant increments in aldolase A and serpin B12 only occurred in the sepsis model. Changes in aldolase A were validated in a larger population of pigs with sepsis due to Streptococcus suis infection. In serum, there were 30 proteins differentially expressed in sepsis group and 26 proteins in the non-septic group, and most of the proteins that changed in both groups were related to non-specific inflammation. In the saliva of the septic animals there were some specific pathways activated, such as the organonitrogen compound metabolic process and lipid transport, whereas, in the serum, one of the main activated pathways was the regulation of protein secretion. Overall, saliva and serum showed different proteome variations in response to septic inflammation and could provide complementary information about the pathophysiological mechanisms occurring in this condition. Additionally, salivary aldolase A could be a potential biomarker of sepsis in pigs that should be confirmed in a larger population.

Biomarkers of sepsis in pigs, horses and cattle: from acute phase proteins to procalcitonin.

Sepsis is a complex clinical syndrome triggered by an inflammatory host response to an infection. It is usually complicated to detect and diagnose, and has severe consequences in human and veterinary health, especially when treatment is not started early. Therefore, efforts to detect sepsis accurately are needed. In addition, its proper diagnosis could reduce the misuse of antibiotics, which is essential fighting against antimicrobial resistance. This case is a particular issue in farm animals, as antibiotics have been traditionally given massively, but now they are becoming increasingly restricted. When sepsis is suspected in animals, the most frequently used biomarkers are acute phase proteins such as C-reactive protein, serum amyloid A and haptoglobin, but their concentrations can increase in other inflammatory conditions. In human patients, the most promising biomarkers to detect sepsis are currently procalcitonin and presepsin, and there is a wide range of other biomarkers under study. However, there is little information on the application of these biomarkers in veterinary species. This review aims to describe the general concepts of sepsis and the current knowledge about the biomarkers of sepsis in pigs, horses, and cattle and to discuss possible advances in the field.

Measurement of procalcitonin in saliva of pigs: a pilot study

BackgroundProcalcitonin (PCT) is a widely used biomarker of sepsis in human medicine and can have potential applications in the veterinary field. This study aimed to explore whether PCT could be measured in the saliva of pigs and whether its concentration changes in sepsis. Therefore, a specific assay was developed and analytically validated, and changes in PCT concentration were evaluated in two conditions: a) in an experimental model of sepsis produced by the administration of lipopolysaccharide (LPS) to pigs (n = 5), that was compared with a model of non-septic inflammation induced by turpentine oil (n = 4), and b) in healthy piglets (n = 11) compared to piglets with meningitis (n = 20), a disease that usually involves sepsis and whose treatment often requires large amounts of antibiotics in farms.ResultsThe assay showed coefficients of variation within the recommended limits and adequate linearity after serial sample dilutions. The method's detection limit was set at 68 μg/L, and the lower limit of quantification was 414 μg/L. In the LPS experiment, higher concentrations of PCT were found after 24 h in the animals injected with LPS (mean = 5790 μg/L) compared to those treated with turpentine oil (mean = 2127 μg/L, P = 0.045). Also, animals with meningitis had higher concentrations of PCT (mean = 21515 μg/L) than healthy pigs (mean = 6096 μg/L, P value < 0.0001).ConclusionsAccording to these results, this assay could be potentially used as a tool for the non-invasive detection of sepsis in pigs, which is currently a topic of high importance due to antibiotic use restriction.

Quantitative proteomics revealed modulation of macrophages by MetQ gene of Streptococcus suis serotype 2

Streptococcus suis serotype 2 (SS2) is a serious zoonotic pathogen; it can lead to symptoms of streptococcal toxic shock syndrome (STSS) in humans and sepsis in pigs, and poses a great threat to public health. The SS2 MetQ gene deletion strain has attenuated antiphagocytosis, although the mechanism of antiphagocytosis and pathogenesis of MetQ in SS2 has remained unclear. In this study, stable isotope labeling by amino acids in cell culture (SILAC) based liquid chromatography–mass spectrometry (LC–MS) and subsequent bioinformatics analysis was used to determine differentially expressed proteins of RAW264.7 cells infected with △MetQ and ZY05719. Proteomic results were verified by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting for selected proteins. Further research was focused mainly on immune system processes related to downregulated proteins, such as Src and Ccl9, and actin cytoskeleton and endocytosis related upregulated proteins, like Pstpip1 and Ppp1r9b. The proteomic results in this study shed light on the mechanism of antiphagocytosis and innate immunity of macrophages infected with △MetQ and ZY05719, which might provide novel targets to prevent or control the infection of SS2.

Identification of conditionally essential genes for Streptococcus suis infection in pigs

ABSTRACT Streptococcus suis is a Gram-positive bacterium and zoonotic pathogen that causes meningitis and sepsis in pigs and humans. The aim of this study was to identify genes required for S. suis infection. We created Tn-Seq libraries in a virulent S. suis strain 10, which was used to inoculate pigs in an intrathecal experimental infection. Comparative analysis of the relative abundance of mutants recovered from different sites of infection (blood, cerebrospinal fluid, and meninges of the brain) identified 361 conditionally essential genes, i.e. required for infection, which is about 18% of the genome. The conditionally essential genes were primarily involved in metabolic and transport processes, regulation, ribosomal structure and biogenesis, transcription, and cell wall membrane and envelope biogenesis, stress defenses, and immune evasion. Directed mutants were created in a set of 10 genes of different genetic ontologies and their role was determined in ex vivo models. Mutants showed different levels of sensitivity to survival in whole blood, serum, cerebrospinal fluid, thermic shock, and stress conditions, as compared to the wild type. Additionally, the role of three selected mutants was validated in co-infection experiments in which pigs were infected with both wild type and isogenic mutant strains. The genetic determinants of infection identified in this work contribute to novel insights in S. suis pathogenesis and could serve as targets for novel vaccines or antimicrobial drugs.

Pdh modulate virulence through reducing stress tolerance and biofilm formation of Streptococcus suis serotype 2

ABSTRACTStreptococcus suis serotype 2 (S. suis 2) is a zoonotic pathogen. It causes meningitis, arthritis, pneumonia and sepsis in pigs, leading to extremely high mortality, which seriously affects public health and the development of the pig industry. Pyruvate dehydrogenase (PDH) is an important sugar metabolism enzyme that is widely present in microorganisms, mammals and higher plants. It catalyzes the irreversible oxidative decarboxylation of pyruvate to acetyl-CoA and reduces NAD+ to NADH. In this study, we found that the virulence of the S. suis ZY05719 sequence type 7 pdh deletion strain (Δpdh) was significantly lower than the wild-type strain (WT) in the mouse infection model. The distribution of viable bacteria in the blood and organs of mice infected with the Δpdh was significantly lower than those infected with WT. Bacterial survival rates were reduced in response to temperature stress, salt stress and oxidative stress. Additionally, compared to WT, the ability to adhere to and invade PK15 cells, biofilm formation and stress resistance of Δpdh were significantly reduced. Moreover, real-time PCR results showed that pdh deletion reduced the expression of multiple adhesion-related genes. However, there was no significant difference in the correlation biological analysis between the complemented strain (CΔpdh) and WT. Moreover, the survival rate of Δpdh in RAW264.7 macrophages was significantly lower than that of the WT strain. This study shows that PDH is involved in the pathogenesis of S. suis 2 and reduction in virulence of Δpdh may be related to the decreased ability to resist stress of the strain.

Antimicrobial peptide Epinecidin-1 promotes complete skin regeneration of methicillin-resistant Staphylococcus aureus-infected burn wounds in a swine model.

This report shows that the antimicrobial peptide (AMP) Epinecidin-1 (Epi-1) efficiently heals MRSA-infected heat burn injuries and provides protection from infection in a pig model. The presence of an optimal level of Epi-1 induces cell proliferation by promoting cell cycle progression through an increase in S-phase cells. Epi-1 also induces proliferation to cover the wounded region in an in vitro cell proliferation assay using immortalized human epithelial HaCaT cells. Next, the in vivo wound healing efficiency of Epi-1 was tested in heat-burned pig skin infected with MRSA under in vivo conditions. Treatment of the injury with Epi-1 for 1 h at six hours post-infection completely healed the wound within 25 days. Conversely, the injury in the untreated control was not healed 25 days post-infection. Histological staining of wound sections with H&E showed that Epi-1 enhanced vascularization and increased epithelial activities in the wound region. Neutrophil recruitment to the wounded region in the Epi-1-treated sections was visualized by Giemsa staining. Additionally, Masson's trichrome staining of wound sections confirmed that Epi-1 enhanced extracellular collagen compound formation. The induction of sepsis-associated blood C-reactive protein (CRP) and the pro-inflammatory cytokine IL-6 in response to MRSA infection was also suppressed in pigs that received Epi-1. Taken together, the results demonstrate that the biomaterial Epi-1 heals wounds through increasing epithelial cell proliferation, vascularization, and the formation of collagen and controls MRSA infection-mediated sepsis in pigs.

Portal Cytokine Response and Metabolic Markers in the Early Stages of Abdominal Sepsis in Pigs

Background: The portal vein could play a major role in disseminating the local inflammation of acute bacterial peritonitis since it is responsible for the venous drainage of the gastrointestinal tract. We hypothesized that after peritoneal exposure to Escherichia coli, a gradient between the portal and systemic levels of cytokines would be expected. Methods: Acute peritonitis was induced by depositing 200 ml of broth with live E. coli in the peritoneal cavity of the animals in the B-group (n = 7). They were then observed for 4 h and compared with a control group (C-group, n = 7). Tumour necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-10 and vascular endothelial growth factor were measured repeatedly in the portal vein and the femoral artery. Portal vein metabolic markers (microdialysis), haemodynamics, biochemistry, plasma volume (PV), fluid shifts and total tissue water content were recorded or calculated. Results: The intervention led to PV contraction, increased fluid extravasation, increased pulmonary vascular resistance and reduced urinary output in the B-group as compared with the C-group. The levels of glucose in the portal vein were reduced in both study groups with no between-group differences. The levels of TNF-α and IL-6 increased markedly in the portal vein as well as in the systemic circulation of the B-group, but no gradient was seen between them. The corresponding levels of TNF-α and IL-6 remained low and stable in the C-group. Conclusion: The portal vein appears to play a minor role in supplying TNF-α and IL-6 to the systemic circulation after peritoneal exposure to a substantial dose of E. coli.

Brain microabscesses in a porcine model of Staphylococcus aureus sepsis

BackgroundSepsis caused by Staphylococcus aureus often leads to brain microabscesses in humans. Animal models of haematogenous brain abscesses would be useful to study this condition in detail. Recently, we developed a model of S. aureus sepsis in pigs and here we report that brain microabscesses develop in pigs with such induced S. aureus sepsis.Twelve pigs were divided into three groups. Nine pigs received an intravenous inoculation of S. aureus once at time 0 h (group 1) or twice at time 0 h and 12 h (groups 2 and 3). In each group the fourth pig served as control. The pigs were euthanized at time 12 h (Group 1), 24 h (Group 2) and 48 h (Group 3) after the first inoculation. The brains were collected and examined histopathologically.ResultsAll inoculated pigs developed sepsis and seven out of nine pigs developed brain microabscesses. The microabscesses contained S. aureus and were located in the prosencephalon and mesencephalon. Chorioditis and meningitis occurred from 12 h after inoculation.ConclusionsPigs with experimental S. aureus sepsis often develop brain microabscesses. The porcine brain pathology mirrors the findings in human sepsis patients. We therefore suggest the pig as a useful animal model of the development of brain microabscesses caused by S. aureus sepsis.

Gene expression patterns in multiple organs in experimentally induced Staphylococcus aureus sepsis in pigs

Gene expression patterns in multiple organs in experimentally induced Staphylococcus aureus sepsis in pigs

Polyvalent immunoglobulin significantly attenuated the formation of IL-1β in Escherichia coli-induced sepsis in pigs

Evidence suggests that adjunctive treatment with intravenous immunoglobulin preparations enriched with IgA and IgM reduce mortality in sepsis. The mode of action of polyvalent immunoglobulin is complex, including neutralization of toxins and modulation of complement activation and cytokine formation toward an anti-inflammatory profile. In this study we explored the effect of Pentaglobin, containing IgG, IgA and IgM, on the initial inflammatory reaction as well as on hemodynamics, using a well characterized and standardized porcine model of sepsis. Anesthetized and mechanically ventilated pigs, mean weight 14.9kg, were allocated into two groups of 8 animals, receiving either Pentaglobin or saline, before sepsis was induced by intravenous Escherichia coli infusion. Five negative controls received saline only. All animals were observed for 4h under extensive invasive monitoring. Pentaglobin significantly (p<0.05) attenuated IL-1β formation by 38% at the end of the experiment, and markedly increased (p<0.05) the formation of IL-10at 60min. TNF-α, IL-6, IL-8 and expression of the cell surface marker wCD11R3 were lower in the Pentaglobin group, but the differences were not significant. The serum concentration of LPS was three times higher in the Pentaglobin group (p<0.005), indicating binding of LPS to Pentaglobin. Complementary in vitro experiments showed a higher binding affinity for IgM and IgA to LPS than for IgG. LPS-induced formation of IL-6 was significantly (p<0.05) attenuated by Pentaglobin in an in vitro whole blood model. In conclusion, Pentaglobin decreased the key inflammasome IL-1β molecule in an E. coli-model of pigs sepsis.

Using the phenylalanine (PHE) stable isotope pulse method to measure intracellular protein breakdown and metabolic shunting in the context of sepsis in the pig

To develop an easy applicable clinical method to measure protein metabolism, we tested the PHE stable isotope pulse method (PULSE) and compared the results with a simultaneously performed primed‐continuous infusion protocol (CONTI) during sepsis in pigs with stimulated whole body protein breakdown (WbRa).12 pigs with Pseudomonas aeroginosa induced hyperdynamic sepsis and 8 controls were studied 17h after start. WbRa CONTI with L‐[13C6]PHE and WbRa‐PULSE with L‐[15N]PHE. Plasma PHE enrichment by LC‐MS, WbRa‐CONTI = I/TTR, compartmental analysis (SAAM II) PULSE. Data (mean (SE)); stats (Prism).WbRa‐CONTI was 22% higher in septic pigs {924 (23) to 1130 (46) nmol/kg BW/min} (p=0.0032), while WbRa‐PULSE 36% {1722 (66) to 2342 (191); p=0.0164}. Sepsis show a substantial expansion of pool 1 and 2 and metabolic shunting (pool 2&gt;&lt;1), while intracellular PB increased 31% {2620 (82) to 3425 (305); p=0.0426}. Ra‐PULSE relates to intracellular PB (p&lt;0.0001) and Ra‐CONTI to Ra‐PULSE (P&lt;0.001).Changes in Ra‐CONTI reflect intracellular PB with high sensitivity. PULSE in addition shows that sepsis in the pig is related to a substantial increase in metabolic shunting in relation to expansion of the pools (probably intra‐ and extracellular). It is suggested that the CONTI method can be replaced with the easy applicable PULSE method that also provides additional information about intracellular fluxes and breakdown.

Experimental sepsis in pigs—effects of vasopressin on renal, hepatic, and intestinal dysfunction

Introduction. Low-dose arginine vasopressin (AVP) has been proposed as an adjunctive vasopressor for the treatment of advanced vasodilatory shock. However, its effects on renal, hepatic, and intestinal dysfunction during sepsis remain controversial.Methods. Fecal peritonitis was induced in 20 anesthetized, invasively monitored, mechanically ventilated female pigs. Following the time point of septic shock (defined as mean artery pressure (MAP) ≤65 mmHg), animals were randomly assigned to the following groups (n = 10): 1) a norepinephrine group with MAP between 65 and 75 mmHg; and 2) an AVP group with a constant infusion rate of 0.5 mU.kg-1.min-1.Results. MAP, pulmonary capillary wedge pressure, hematocrit, TNF-α, IL-6, and IL-10 were similar in the two groups during the 28-h observation period. Infusion of AVP was associated with lower total norepinephrine and fluid requirements. There was a statistically significant improvement in renal function as assessed by increased urine output and renal blood flow, and decreased serum creatinine, in the AVP group when compared with the norepinephrine group (P < 0.05). Histological analyses of the intestine, liver, and kidney showed similar light microscopical appearance of the two groups. Apoptotic cells in the liver were significantly fewer in the AVP group when compared with the norepinephrine group (P < 0.05).Conclusion. An adjunctive AVP to norepinephrine infusion exhibits a favorable impact on renal function without deleterious effects on the liver and intestine in a porcine model of experimental sepsis when compared with norepinephrine infusion alone.

A Case ofStreptococcus suisInfection Causing Pneumonia with Empyema in Korea

Streptococcus suis causes meningitis and sepsis in pigs, but human infection has increased over the past few years in those who are exposed to pigs or raw pork. Most cases have occurred in Southeast Asia, but only two cases have been reported in South Korea, presenting with arthritis and meningitis. Here, we report a rare case of S. suis infection, a 60-year-old sailor, who visited the emergency room presenting septicemia, pneumonia with empyema and meningitis, showed full recovery; however, neurologic sequale of severe cognitive dysfunction was present after the usage of antibiotics and percutaneous drainage. S. suis was isolated from blood and pleural fluid and the strain was susceptible to penicillin and vancomycin. Increased awareness of S. suis infection and prevention are warranted.

Ornithodoros moubata complement inhibitor (OmCI) is an equally effective C5 inhibitor in pig and human, and combined with CD14 inhibition, efficiently attenuate Escherichia coli-induced sepsis in pigs

Ornithodoros moubata complement inhibitor (OmCI) is an equally effective C5 inhibitor in pig and human, and combined with CD14 inhibition, efficiently attenuate Escherichia coli-induced sepsis in pigs

Assessments of skin and tongue microcirculation reveals major changes in porcine sepsis

To examine the relation between central hemodynamics, clinical severity and microvascular findings in tongue and skin during sepsis. Skin and tongue microcirculation was examined using laser Doppler and video microscopy techniques before and 200 min after inducing sepsis in pigs (n=6) by inactivated Neisseria meningitides and in two control animals. All infected pigs developed clinical signs of sepsis. Pericapillary bleedings developed in the tongue in the two pigs with the most severe disease. Capillary density increased in the groin skin in infected pigs after 200 min as compared to baseline (P<0·02). In the same period, mean capillary flow velocity was reduced in groin skin and tongue in septic pigs (P<0·02). At 200 min a fraction of capillaries had developed 'no flow' or 'brisk flow', patterns hardly seen at baseline. Laser Doppler perfusion was reduced in ear and tongue after 200 min (P<0·02 for both). The described pathology was more pronounced in the pigs with the most severe sepsis. Capillary bleedings may be used as an early indication of severe sepsis. Examination of skin and tongue microcirculations may be used to characterize severity of sepsis and possibly to assess effect of treatment.