RESUMEN
Skin/soft tissue infections (SSTIs) caused by methicillin-resistant Staphylococcus aureus (MRSA) pose a major healthcare burden. Distinct inflammatory and resolution phases comprise the host immune response to SSTIs. Resolution is a myeloid PPARγ-dependent anti-inflammatory phase that is essential for the clearance of MRSA. However, the signals activating PPARγ to induce resolution remain unknown. Here, we demonstrate that myeloid glucose transporter 1 (GLUT-1) is essential for the onset of resolution. MRSA-challenged macrophages are unsuccessful in generating an oxidative burst or immune radicals in the absence of GLUT-1 due to a reduction in the cellular NADPH pool. This translates in vivo as a significant reduction in lipid peroxidation products required for the activation of PPARγ in MRSA-infected mice lacking myeloid GLUT-1. Chemical induction of PPARγ during infection circumvents this GLUT-1 requirement and improves resolution. Thus, GLUT-1-dependent oxidative burst is essential for the activation of PPARγ and subsequent resolution of SSTIs.
Asunto(s)
Transportador de Glucosa de Tipo 1 , Staphylococcus aureus Resistente a Meticilina , Infecciones de los Tejidos Blandos , Animales , Transportador de Glucosa de Tipo 1/metabolismo , Transportador de Glucosa de Tipo 1/genética , Ratones , Infecciones de los Tejidos Blandos/microbiología , Infecciones de los Tejidos Blandos/metabolismo , Infecciones de los Tejidos Blandos/patología , PPAR gamma/metabolismo , Infecciones Cutáneas Estafilocócicas/microbiología , Infecciones Cutáneas Estafilocócicas/metabolismo , Infecciones Cutáneas Estafilocócicas/patología , Infecciones Cutáneas Estafilocócicas/tratamiento farmacológico , Ratones Endogámicos C57BL , Macrófagos/metabolismo , Macrófagos/microbiología , Infecciones Estafilocócicas/metabolismo , Infecciones Estafilocócicas/microbiologíaRESUMEN
A model-informed drug development approach was used to select ceftaroline fosamil high-dose regimens for pediatric patients with complicated skin and soft-tissue infections caused by Staphylococcus aureus with a ceftaroline minimum inhibitory concentration (MIC) of 2 or 4 mg/L. Steady-state ceftaroline concentrations were simulated using a population pharmacokinetics (PK) model for ceftaroline fosamil and ceftaroline including data from 304 pediatric subjects and 944 adults. Probability of target attainment (PTA) for various simulated pediatric high-dose regimens and renal function categories were calculated based on patients achieving 35% fT>MIC (S. aureus PK/pharmacodynamic target for 2-log10 bacterial killing). For extrapolation of efficacy, simulated exposures and PTA were compared to adults with normal renal function receiving high-dose ceftaroline fosamil (600 mg 2-h infusions every 8 h). For safety, predicted ceftaroline exposures were compared with observed pediatric and adult data. Predicted ceftaroline exposures for the approved pediatric high-dose regimens (12, 10, or 8 mg/kg by 2-h infusions every 8 h for patients aged >2 to <18 years with normal/mild, moderate, or severe renal impairment, respectively; 10 mg/kg by 2-h infusions every 8 h for patients aged ≥2 months to <2 years with normal renal function/mild impairment) were well matched to adults with normal renal function. Median predicted maximum concentration at steady state (Cmax,ss ) and area under the plasma concentration-time curve over 24 h at steady state pediatric to adult ratios were 0.907-1.33 and 0.940-1.41, respectively. PTAs (>99% and ≥81% for MICs of 2 and 4 mg/L, respectively) matched or exceeded the adult predictions. Simulated Cmax,ss values were below the maximum observed data in other indications, including a high-dose pediatric pneumonia trial, which reported no adverse events related to high exposure.
Asunto(s)
Antibacterianos/administración & dosificación , Cefalosporinas/administración & dosificación , Modelos Biológicos , Enfermedades Cutáneas Infecciosas/tratamiento farmacológico , Infecciones de los Tejidos Blandos/tratamiento farmacológico , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus , Adolescente , Adulto , Antibacterianos/sangre , Antibacterianos/farmacocinética , Cefalosporinas/sangre , Cefalosporinas/farmacocinética , Niño , Preescolar , Ensayos Clínicos como Asunto , Simulación por Computador , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Pruebas de Sensibilidad Microbiana , Insuficiencia Renal/sangre , Insuficiencia Renal/metabolismo , Enfermedades Cutáneas Infecciosas/sangre , Enfermedades Cutáneas Infecciosas/metabolismo , Infecciones de los Tejidos Blandos/sangre , Infecciones de los Tejidos Blandos/metabolismo , Infecciones Estafilocócicas/sangre , Infecciones Estafilocócicas/metabolismo , CeftarolinaRESUMEN
In necrotizing soft tissue infection (NSTI) there is a need to identify biomarker sets that can be used for diagnosis and disease management. The INFECT study was designed to obtain such insights through the integration of patient data and results from different clinically relevant experimental models by use of systems biology approaches. This chapter describes the current state of biomarkers in NSTI and how biomarkers are categorized. We introduce the fundamentals of top-down systems biology approaches including analysis tools and we review the use of current methods and systems biology approaches to biomarker discover. Further, we discuss how different "omics" signatures (gene expression, protein, and metabolites) from NSTI patient samples can be used to identify key host and pathogen factors involved in the onset and development of infection, as well as exploring associations to disease outcomes.
Asunto(s)
Biomarcadores/análisis , Infecciones de los Tejidos Blandos/metabolismo , Infecciones de los Tejidos Blandos/patología , Biología de Sistemas , Humanos , Necrosis , Pronóstico , Infecciones de los Tejidos Blandos/diagnósticoRESUMEN
BACKGROUND AND AIMS: The link between diabetes and increased risk of infectious disease has long been recognized, but has re-entered sharp focus following the COVID-19 pandemic. METHODS: A literature search was conducted in PubMed for articles in English on diabetes and infection. RESULTS: Diabetes predisposes to infections through alterations in innate and acquired immune defenses. Outcomes of infection are worse in people with uncontrolled diabetes, and infection can worsen hyperglycemia in hitherto well controlled diabetes (bidirectional relationship). Diabetes does not increase the risk of infection with COVID-19 per se, but predisposes to severe disease and poor outcomes. COVID-19 has also been linked to deterioration of glycemic control as well as new-onset diabetes. CONCLUSIONS: Clinicians caring for people with diabetes should be aware of the increased risk of infections in this population, as well as the possibility of worsening hyperglycemia. A holistic approach with frequent monitoring of blood glucose levels and appropriate titration of medications, along with close attention to nutritional status, is essential to ensure the best possible outcomes.
Asunto(s)
COVID-19/epidemiología , Diabetes Mellitus/epidemiología , Tuberculosis Pulmonar/epidemiología , Inmunidad Adaptativa/inmunología , Glucemia/metabolismo , COVID-19/inmunología , COVID-19/metabolismo , Diabetes Mellitus/inmunología , Diabetes Mellitus/metabolismo , Control Glucémico , Humanos , Inmunidad Innata/inmunología , India/epidemiología , Infecciones/epidemiología , Infecciones/inmunología , Infecciones/metabolismo , Infecciones del Sistema Genital/epidemiología , Infecciones del Sistema Genital/inmunología , Infecciones del Sistema Genital/metabolismo , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/inmunología , Infecciones del Sistema Respiratorio/metabolismo , Factores de Riesgo , SARS-CoV-2 , Índice de Severidad de la Enfermedad , Enfermedades Cutáneas Bacterianas/epidemiología , Enfermedades Cutáneas Bacterianas/inmunología , Enfermedades Cutáneas Bacterianas/metabolismo , Infecciones de los Tejidos Blandos/epidemiología , Infecciones de los Tejidos Blandos/inmunología , Infecciones de los Tejidos Blandos/metabolismo , Tuberculosis Pulmonar/inmunología , Tuberculosis Pulmonar/metabolismo , Infecciones Urinarias/epidemiología , Infecciones Urinarias/inmunología , Infecciones Urinarias/metabolismoRESUMEN
Streptococcus pyogenes (group A Streptococcus [GAS]), a major human-specific pathogen, relies on efficient nutrient acquisition for successful infection within its host. The phosphotransferase system (PTS) couples the import of carbohydrates with their phosphorylation prior to metabolism and has been linked to GAS pathogenesis. In a screen of an insertional mutant library of all 14 annotated PTS permease (EIIC) genes in MGAS5005, the annotated ß-glucoside PTS transporter (bglP) was found to be crucial for GAS growth and survival in human blood and was validated in another M1T1 GAS strain, 5448. In 5448, bglP was shown to be in an operon with a putative phospho-ß-glucosidase (bglB) downstream and a predicted antiterminator (licT) upstream. Using defined nonpolar mutants of the ß-glucoside permease (bglP) and ß-glucosidase enzyme (bglB) in 5448, we showed that bglB, not bglP, was important for growth in blood. Furthermore, transcription of the licT-blgPB operon was found to be repressed by glucose and induced by the ß-glucoside salicin as the sole carbon source. Investigation of the individual bglP and bglB mutants determined that they influence in vitro growth in the ß-glucoside salicin; however, only bglP was necessary for growth in other non-ß-glucoside PTS sugars, such as fructose and mannose. Additionally, loss of BglP and BglB suggests that they are important for the regulation of virulence-related genes that control biofilm formation, streptolysin S (SLS)-mediated hemolysis, and localized ulcerative lesion progression during subcutaneous infections in mice. Thus, our results indicate that the ß-glucoside PTS transports salicin and its metabolism can differentially influence GAS pathophysiology during soft tissue infection.
Asunto(s)
Alcoholes Bencílicos/metabolismo , Glucósidos/metabolismo , Sistema de Fosfotransferasa de Azúcar del Fosfoenolpiruvato/metabolismo , Infecciones de los Tejidos Blandos/patología , Infecciones Estreptocócicas/patología , Streptococcus pyogenes/metabolismo , Streptococcus pyogenes/patogenicidad , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Biopelículas/crecimiento & desarrollo , Represión Catabólica , Regulación Bacteriana de la Expresión Génica , Hemólisis/genética , Humanos , Ratones , Viabilidad Microbiana/genética , Mutación , Operón , Sistema de Fosfotransferasa de Azúcar del Fosfoenolpiruvato/genética , Infecciones de los Tejidos Blandos/metabolismo , Infecciones de los Tejidos Blandos/microbiología , Infecciones Estreptocócicas/metabolismo , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/genética , Streptococcus pyogenes/crecimiento & desarrollo , Azúcares/metabolismo , Virulencia/genéticaRESUMEN
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of infection worldwide, including a wide array of both hospital- and community-acquired infections-most commonly bacteremia, upper and lower respiratory tract infection, skin and soft-tissue infection, osteomyelitis, and septic arthritis. This chapter describes the epidemiology of MRSA infection, its ability to confer antibiotic resistance and produce a wide array of virulence factors, and its pivotal role in human infection, especially cystic fibrosis. It also provides an introduction to the strategies for treatment of both chronic and acute MRSA infections.
Asunto(s)
Infecciones Comunitarias Adquiridas , Fibrosis Quística , Staphylococcus aureus Resistente a Meticilina , Infecciones del Sistema Respiratorio , Infecciones de los Tejidos Blandos , Infecciones Estafilocócicas , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/metabolismo , Infecciones Comunitarias Adquiridas/terapia , Fibrosis Quística/epidemiología , Fibrosis Quística/metabolismo , Humanos , Staphylococcus aureus Resistente a Meticilina/metabolismo , Staphylococcus aureus Resistente a Meticilina/patogenicidad , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/metabolismo , Infecciones del Sistema Respiratorio/terapia , Infecciones de los Tejidos Blandos/epidemiología , Infecciones de los Tejidos Blandos/metabolismo , Infecciones de los Tejidos Blandos/terapia , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/metabolismo , Infecciones Estafilocócicas/terapia , Factores de Virulencia/metabolismoRESUMEN
Staphylococcus aureus is the most prominent cause of skin and soft tissue infections (SSTI) worldwide. Mortality associated with invasive SSTI is a major threat to public health considering the incidence of antibiotic resistant isolates in particular methicillin resistant S. aureus both in the hospital (HA-MRSA) and in the community (CA-MRSA). To overcome the increasing difficulties in the clinical management of SSTI due to MRSA, new prophylactic and therapeutic approaches are urgently needed and a preventive vaccine would be welcome. The rational design of an anti-S. aureus vaccine requires a deep knowledge of the role that the different bacterial virulence factors play according to the type of infection. In the present study, using a set of isogenic deficient mutants and their complemented strains we determined that the staphylococcal surface proteins SpA and Sbi play an important role in the induction of inflammatory cytokines and chemokines in the skin during SSTI. SpA and Sbi initiate signaling cascades that lead to the early recruitment of neutrophils, modulate their lifespan in the skin milieu and contribute to proper abscess formation and bacterial eradication. Moreover, the expression of SpA and Sbi appear critical for skin repair and wound healing. Thus, these results indicate that SpA and Sbi can promote immune responses in the skin that are beneficial for the host and therefore, should not be neutralized with vaccine formulations designed to prevent SSTI.
Asunto(s)
Absceso/inmunología , Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/metabolismo , Proteínas Portadoras/metabolismo , Piel/inmunología , Infecciones de los Tejidos Blandos/metabolismo , Infecciones Estafilocócicas/metabolismo , Staphylococcus aureus/metabolismo , Cicatrización de Heridas/fisiología , Absceso/metabolismo , Absceso/microbiología , Animales , Quimiocinas/metabolismo , Citocinas/metabolismo , Modelos Animales de Enfermedad , Humanos , Queratinocitos , Staphylococcus aureus Resistente a Meticilina/metabolismo , Staphylococcus aureus Resistente a Meticilina/patogenicidad , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Piel/microbiología , Piel/patología , Infecciones de los Tejidos Blandos/inmunología , Infecciones de los Tejidos Blandos/microbiología , Infecciones de los Tejidos Blandos/patología , Infecciones Estafilocócicas/inmunología , Staphylococcus aureus/patogenicidadRESUMEN
Necrotizing soft tissue infections (NSTI) have a 90-day mortality rate of 18-22%. Tools are needed for estimating the prognosis and severity of NSTI upon admission. We evaluated soluble urokinase-type plasminogen activator receptor (suPAR) levels at admission as a prognostic marker of NSTI severity and mortality. In a prospective, observational cohort study, suPAR was measured in 200 NSTI patients. We compared admission suPAR levels in survivors and non-survivors, patients with septic shock and non-shock, amputation and non-amputation, correlations with Simplified Acute Physiology Score II (SAPS II) and the Sequential Organ Failure Assessment (SOFA) score. Admission suPAR levels were higher in septic shock vs. non-septic shock patients (9.2 vs. 5.8 ng/mL, p-value < 0.001) and non-survivors vs. survivors (11 vs. 6.1 ng/mL, p-value < 0.001) and correlated with SAPS II (r = 0.52, p < 0.001) and SOFA score (r = 0.64, p < 0.001). Elevated suPAR upon admission was associated with 90-day mortality (log-rank test p < 0.001), however not after adjustment for age, sex, and SOFA score. The AUC for suPAR and 90-day mortality was 0.77. We found that suPAR is a promising candidate for prognosis and severity in patients with NSTI.
Asunto(s)
Infecciones de los Tejidos Blandos/mortalidad , Infecciones de los Tejidos Blandos/patología , Anciano , Biomarcadores , Estudios de Cohortes , Femenino , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Receptores del Activador de Plasminógeno Tipo Uroquinasa/genética , Receptores del Activador de Plasminógeno Tipo Uroquinasa/metabolismo , Sepsis/metabolismo , Sepsis/mortalidad , Sepsis/patología , Choque Séptico/metabolismo , Choque Séptico/mortalidad , Choque Séptico/patología , Infecciones de los Tejidos Blandos/metabolismoRESUMEN
Background:Staphylococcus aureus is a significant pathogen implicated in numerous nosocomial and community-acquired infections. The Panton-Valentine leukocidin (PVL) can be associated with severe necrotizing diseases such as pneumonia, skin and soft tissue infection (SSTI). Methods: In total, 96 S. aureus isolates were obtained from patients presenting with wounds (n=48) and soft tissue infections (SSTIs, n=48). These were characterized based on their antimicrobial susceptibility profile, the possession of virulence genes (e.g. capsular type, PVL), accessory gene regulator ( agr) type, and the staphylococcal protein A ( spa) type. The production of the PVL protein was assessed by western blotting. Results: All isolates were susceptible to methicillin. The resistance was highest to penicillin (97.9%), followed by trimethoprim/sulfamethoxazole (85.4%) and tetracycline (10.4%). The PVL gene was found in 83.3% of isolates from SSTIs and in 79.2% of isolates from wound. Of these, 53 (68%) produced PVL as assessed by western blotting. The most prevalent spa type was the t084 (78.1%, n=75) and, majority of the isolates carried agr2 (82.3%, n=79). Conclusions: Prevalence of antibiotic resistant PVL-positive methicillin susceptible S. aureus strains has severe implications on PVL mediated infections.
Asunto(s)
Toxinas Bacterianas/metabolismo , Exotoxinas/metabolismo , Leucocidinas/metabolismo , Enfermedades de la Piel/metabolismo , Infecciones de los Tejidos Blandos/metabolismo , Infecciones Estafilocócicas/metabolismo , Staphylococcus aureus/metabolismo , Estudios Transversales , Farmacorresistencia Bacteriana , Humanos , Pruebas de Sensibilidad Microbiana , Nigeria , Enfermedades de la Piel/microbiología , Infecciones de los Tejidos Blandos/microbiología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacosRESUMEN
AIMS: Calcium sulphate (CaSO4) is a resorbable material that can be used simultaneously as filler of a dead space and as a carrier for the local application of antibiotics. Our aim was to describe the systemic exposure and the wound fluid concentrations of vancomycin in patients treated with vancomycin-loaded CaSO4 as an adjunct to the routine therapy of bone and joint infections. PATIENTS AND METHODS: A total of 680 post-operative blood and 233 wound fluid samples were available for analysis from 94 implantations performed in 87 patients for various infective indications. Up to 6 g of vancomycin were used. Non-compartmental pharmacokinetic analysis was performed on the data from 37 patients treated for an infection of the hip. RESULTS: The overall systemic exposure remained within a safe range, even in patients with post-operative renal failure, none requiring removal of the pellets. Local concentrations were approximately ten times higher than with polymethylmethacrylate (PMMA) as a carrier, but remained below reported cell toxicity thresholds. Decreasing concentrations in wound fluid were observed over several weeks, but remained above the common minimum inhibitory concentrations for Staphylococcus up to three months post-operatively. CONCLUSION: This study provides the first pharmacokinetic description of the local application of vancomycin with CaSO4 as a carrier, documenting slow release, systemic safety and a release profile far more interesting than from PMMA. In particular, considering in vitro data, concentrations of vancomycin active against staphylococcal biofilm were seen for several weeks. Cite this article: Bone Joint J 2017;99-B:1537-44.
Asunto(s)
Antibacterianos/farmacocinética , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Infecciones por Bacterias Grampositivas/tratamiento farmacológico , Osteomielitis/tratamiento farmacológico , Infecciones Relacionadas con Prótesis/tratamiento farmacológico , Infecciones de los Tejidos Blandos/tratamiento farmacológico , Vancomicina/farmacocinética , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/metabolismo , Antibacterianos/uso terapéutico , Sulfato de Calcio , Portadores de Fármacos , Femenino , Infecciones por Bacterias Gramnegativas/metabolismo , Infecciones por Bacterias Grampositivas/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Ortopédicos/instrumentación , Osteomielitis/metabolismo , Estudios Prospectivos , Infecciones Relacionadas con Prótesis/metabolismo , Infecciones de los Tejidos Blandos/metabolismo , Vancomicina/metabolismo , Vancomicina/uso terapéuticoRESUMEN
PURPOSE OF REVIEW: Skin and soft tissue infections (SSTIs) are prevalent in the obese population, with rising trend expected. Although numerous antibiotics are available for the prevention and treatment of SSTIs, their characterization in obese patients is not a regulatory mandate. Consequently, information that carries importance for optimizing the dosing regimen in the obese population may not be readily available. This review focuses on the most recent pharmacokinetic and pharmacodynamic data on this topic with attention to cefazolin for surgical prophylaxis as well as antibiotics that are active against methicillin-resistant Staphylococcus aureus (MRSA). Moreover, the implications for optimizing SSTIs prevention and treatment in the obese population will also be discussed. RECENT FINDINGS: On the basis of pharmacokinetic/pharmacodynamic considerations, most studies found a perioperative prophylactic cefazolin regimen of 2âg to be reasonable in the case of obese patients undergoing cesarean delivery or bariatric surgery. There is general paucity of data regarding the pharmacokinetic/pharmacodynamic characteristics of antimicrobials active against MRSA in obese patients, especially for the target tissue. Therapeutic drug monitoring has been correlated with pharmacokinetic/pharmacodynamic optimization for vancomycin and teicoplanin, and should be used in these cases. There is more supportive evidence for the use of oxazolidinones (linezolid and tedizolid), daptomycin and lipoglycopeptides (telavancin, dalbavancin and oritavancin) in the management of SSTIs in this population. SUMMARY: The pharmacokinetic/pharmacodynamic approach, which can be used as a basis or supplement to clinical trials, provides valuable data and decision-making tools for optimizing regimens used for both prevention and treatment of SSTIs in the obese population. Important pharmacokinetic/pharmacodynamic characteristics of antibiotics, such as the penetration into the subcutaneous tissue and the probability of reaching the pharmacodynamic, target dictate efficacy, and thus should be taken into account and further investigated.
Asunto(s)
Antibacterianos/uso terapéutico , Obesidad/complicaciones , Enfermedades Cutáneas Bacterianas/tratamiento farmacológico , Enfermedades Cutáneas Bacterianas/prevención & control , Infecciones de los Tejidos Blandos/tratamiento farmacológico , Infecciones de los Tejidos Blandos/prevención & control , Antibacterianos/administración & dosificación , Antibacterianos/farmacocinética , Humanos , Staphylococcus aureus Resistente a Meticilina , Obesidad/metabolismo , Obesidad/cirugía , Enfermedades Cutáneas Bacterianas/metabolismo , Infecciones de los Tejidos Blandos/metabolismo , Infecciones Cutáneas Estafilocócicas/tratamiento farmacológico , Infecciones Cutáneas Estafilocócicas/prevención & controlRESUMEN
PURPOSE: An understanding of the pharmacokinetic (PK) and pharmacodynamic (PD) principles that determine response to antimicrobial therapy can provide the clinician with better-informed dosing regimens. Factors influential on antibiotic disposition and clinical outcome are presented, with a focus on the primary site of infection. Techniques to better understand antibiotic PK and optimize PD are acknowledged. METHODS: PubMed (inception-April 2016) was reviewed for relevant publications assessing antimicrobial exposures within different anatomic locations and clinical outcomes for various infection sites. FINDINGS: A limited literature base indicates variable penetration of antibiotics to different target sites of infection, with drug solubility and extent of protein binding providing significant PK influences in addition to the major clearing pathway of the agent. PD indices derived from in vitro studies and animal models determine the optimal magnitude and frequency of dosing regimens for patients. PK/PD modeling and simulation has been shown an efficient means of assessing these PD endpoints against a variety of PK determinants, clarifying the unique effects of infection site and patient characteristics to inform the adequacy of a given antibiotic regimen. IMPLICATIONS: Appreciation of the PK properties of an antibiotic and its PD measure of efficacy can maximize the utility of these life-saving drugs. Unfortunately, clinical data remain limited for a number of infection site-antibiotic exposure relationships. Modeling and simulation can bridge preclinical and patient data for the prescription of optimal antibiotic dosing regimens, consistent with the tenets of personalized medicine.
Asunto(s)
Antibacterianos/farmacocinética , Infecciones Bacterianas/tratamiento farmacológico , Animales , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Bacteriemia/sangre , Bacteriemia/tratamiento farmacológico , Infecciones Bacterianas/metabolismo , Huesos/metabolismo , Relación Dosis-Respuesta a Droga , Humanos , Pulmón/metabolismo , Infecciones de los Tejidos Blandos/tratamiento farmacológico , Infecciones de los Tejidos Blandos/metabolismoRESUMEN
The exoproteome of Staphylococcus aureus contains enzymes and virulence factors that are important for host adaptation. We investigated the exoprotein profiles and cytokine/chemokine responses obtained in three different S. aureus-host interaction scenarios by using two-dimensional gel electrophoresis (2-DGE) and two-dimensional immunoblotting (2D-IB) combined with tandem mass spectrometry (MS/MS) and cytometric bead array techniques. The scenarios included S. aureus bacteremia, skin and soft tissue infections (SSTIs), and healthy carriage. By the 2-DGE approach, 12 exoproteins (the chaperone protein DnaK, a phosphoglycerate kinase [Pgk], the chaperone GroEL, a multisensor hybrid histidine kinase, a 3-methyl-2-oxobutanoate hydroxymethyltransferase [PanB], cysteine synthase A, an N-acetyltransferase, four isoforms of elongation factor Tu [EF-Tu], and one signature protein spot that could not be reliably identified by MS/MS) were found to be consistently present in more than 50% of the bacteremia isolates, while none of the SSTI or healthy-carrier isolates showed any of these proteins. By the 2D-IB approach, we also identified five antigens (methionine aminopeptidase [MetAPs], exotoxin 15 [Set15], a peptidoglycan hydrolase [LytM], an alkyl hydroperoxide reductase [AhpC], and a haptoglobin-binding heme uptake protein [HarA]) specific for SSTI cases. Cytokine and chemokine production varied during the course of different infection types and carriage. Monokine induced by gamma interferon (MIG) was more highly stimulated in bacteremia patients than in SSTI patients and healthy carriers, especially during the acute phase of infection. MIG could therefore be further explored as a potential biomarker of bacteremia. In conclusion, 12 exoproteins from bacteremia isolates, MIG production, and five antigenic proteins identified during SSTIs should be further investigated for potential use as diagnostic markers.
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Bacteriemia/inmunología , Proteínas Bacterianas/análisis , Proteínas Bacterianas/inmunología , Proteómica , Infecciones Estafilocócicas/inmunología , Infecciones Estafilocócicas/metabolismo , Staphylococcus aureus/metabolismo , Anticuerpos Antibacterianos/sangre , Bacteriemia/metabolismo , Bacteriemia/microbiología , Biomarcadores/sangre , Quimiocina CXCL9/sangre , Quimiocinas/sangre , Quimiocinas/inmunología , Citocinas/sangre , Citocinas/inmunología , Electroforesis en Gel Bidimensional , Interacciones Huésped-Patógeno , Humanos , Inflamación , Masculino , Persona de Mediana Edad , Proyectos Piloto , Infecciones de los Tejidos Blandos/inmunología , Infecciones de los Tejidos Blandos/metabolismo , Infecciones de los Tejidos Blandos/microbiología , Infecciones Estafilocócicas/microbiología , Infecciones Cutáneas Estafilocócicas/inmunología , Infecciones Cutáneas Estafilocócicas/metabolismo , Infecciones Cutáneas Estafilocócicas/microbiología , Staphylococcus aureus/patogenicidad , Espectrometría de Masas en TándemRESUMEN
Methicillin-resistant Staphylococcus aureus (MRSA) producing Panton-Valentine leukocidin (PVL) is highly virulent. This study aimed to compare the efficacy of tigecycline versus vancomycin in experimental thigh abscess by a PVL-producing MRSA isolate. One hundred and ninety-six Wistar rats were divided into five groups: group A, controls; groups B and C, administered vancomycin starting 1 and 6 h after bacterial challenge respectively; groups D and E, administered tigecycline starting 1 and 6 h after bacterial challenge respectively. Treatment was continued every 12 hours for three consecutive days. Survival was recorded; separate animals were killed for quantitative cultures. Serum samples were collected for estimation of malondialdehyde (MDA). Survival of group D was prolonged compared to all other groups. The bacterial load of blood, liver, spleen and lung was significantly decreased within group D compared to group B at 36 hours. Treatment with tigecycline was accompanied by significant reduction of serum MDA at 24 hours. Tigecycline is comparable to vancomycin for the treatment of soft tissue infections by PVL-producing MRSA.
Asunto(s)
Antibacterianos/uso terapéutico , Toxinas Bacterianas/biosíntesis , Exotoxinas/biosíntesis , Leucocidinas/biosíntesis , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Minociclina/análogos & derivados , Infecciones de los Tejidos Blandos/tratamiento farmacológico , Infecciones Estafilocócicas/tratamiento farmacológico , Vancomicina/uso terapéutico , Absceso/tratamiento farmacológico , Absceso/inmunología , Absceso/metabolismo , Absceso/microbiología , Animales , Antibacterianos/administración & dosificación , Carga Bacteriana/efectos de los fármacos , Esquema de Medicación , Huésped Inmunocomprometido/efectos de los fármacos , Huésped Inmunocomprometido/inmunología , Inyecciones Intraperitoneales , Estimación de Kaplan-Meier , Peroxidación de Lípido , Masculino , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Staphylococcus aureus Resistente a Meticilina/metabolismo , Staphylococcus aureus Resistente a Meticilina/patogenicidad , Minociclina/administración & dosificación , Minociclina/uso terapéutico , Distribución Aleatoria , Ratas Wistar , Infecciones de los Tejidos Blandos/inmunología , Infecciones de los Tejidos Blandos/metabolismo , Infecciones de los Tejidos Blandos/microbiología , Infecciones Estafilocócicas/inmunología , Infecciones Estafilocócicas/metabolismo , Infecciones Estafilocócicas/microbiología , Muslo , Tigeciclina , Vancomicina/administración & dosificación , Virulencia/efectos de los fármacosRESUMEN
The underlying pathology of diabetic wounds, i.e. impairment of macro- and microcirculation, might also impact target site penetration of antibacterial drugs. To compare tissue concentrations of linezolid in infected and not infected tissue 10 patients suffering from type 2 diabetes with foot infection were included in the study. Tissue penetration of linezolid was assessed using in vivo microdialysis at the site of infection as well as in non-inflamed subcutaneous adipose tissue. All patients were investigated after receiving a single dose of linezolid and five patients in addition at steady state. After a single dose of linezolid significantly higher area under the concentration vs. time curve over 8 hours (AUC0-8 ) and maximum concentrations (Cmax )-values were observed in plasma (65.5 ± 21.2 mg*h/L and 16.4 ± 4.6 mg/L) as compared to inflamed (36.3 ± 22.9 mg*h/L and 6.6 ± 3.6 mg/L) and non-inflamed tissue (33.0 ± 17.7 mg*h/L and 6.7 ± 3.6 mg/L). Multiple administrations of linezolid led to disappearance of significant differences in Cmax and AUC0-8 between plasma, inflamed, and non-inflamed tissue. Approximately 2-fold increase of Cmax and AUC0-8 -values in tissue was observed at steady state as compared to the first administration. Penetration of linezolid is not impaired in diabetic foot infection but equilibrium between plasma and tissue might be delayed.
Asunto(s)
Acetamidas/farmacocinética , Antiinfecciosos/farmacocinética , Diabetes Mellitus Tipo 2/metabolismo , Enfermedades del Pie/metabolismo , Oxazolidinonas/farmacocinética , Infecciones de los Tejidos Blandos/metabolismo , Acetamidas/administración & dosificación , Acetamidas/sangre , Anciano , Anciano de 80 o más Años , Antiinfecciosos/administración & dosificación , Antiinfecciosos/sangre , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Femenino , Enfermedades del Pie/tratamiento farmacológico , Humanos , Linezolid , Masculino , Microdiálisis , Persona de Mediana Edad , Oxazolidinonas/administración & dosificación , Oxazolidinonas/sangre , Infecciones de los Tejidos Blandos/tratamiento farmacológicoRESUMEN
Obtaining essential nutrients, such as carbohydrates, is an important process for bacterial pathogens to successfully colonize host tissues. The phosphoenolpyruvate phosphotransferase system (PTS) is the primary mechanism by which bacteria transport sugars and sense the carbon state of the cell. The group A streptococcus (GAS) is a fastidious microorganism that has adapted to a variety of niches in the human body to elicit a wide array of diseases. A ΔptsI mutant (enzyme I [EI] deficient) generated in three different strains of M1T1 GAS was unable to grow on multiple carbon sources (PTS and non-PTS). Complementation with ptsI expressed under its native promoter in single copy was able to rescue the growth defect of the mutant. In a mouse model of GAS soft tissue infection, all ΔptsI mutants exhibited a significantly larger and more severe ulcerative lesion than mice infected with the wild type. Increased transcript levels of sagA and streptolysin S (SLS) activity during exponential-phase growth was observed. We hypothesized that early onset of SLS activity would correlate with the severity of the lesions induced by the ΔptsI mutant. In fact, infection of mice with a ΔptsI sagB double mutant resulted in a lesion comparable to that of either the wild type or a sagB mutant alone. Therefore, a functional PTS is not required for subcutaneous skin infection in mice; however, it does play a role in coordinating virulence factor expression and disease progression.
Asunto(s)
Proteínas Bacterianas/metabolismo , Sistema de Fosfotransferasa de Azúcar del Fosfoenolpiruvato/metabolismo , Infecciones de los Tejidos Blandos/metabolismo , Infecciones Estreptocócicas/metabolismo , Streptococcus pyogenes/metabolismo , Estreptolisinas/metabolismo , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/inmunología , Carbohidratos/inmunología , Exotoxinas/genética , Exotoxinas/inmunología , Exotoxinas/metabolismo , Femenino , Genes Bacterianos/genética , Genes Bacterianos/inmunología , Ratones , Mutación/genética , Mutación/inmunología , Sistema de Fosfotransferasa de Azúcar del Fosfoenolpiruvato/genética , Sistema de Fosfotransferasa de Azúcar del Fosfoenolpiruvato/inmunología , Infecciones de los Tejidos Blandos/genética , Infecciones de los Tejidos Blandos/inmunología , Infecciones de los Tejidos Blandos/microbiología , Infecciones Cutáneas Estafilocócicas/genética , Infecciones Cutáneas Estafilocócicas/inmunología , Infecciones Cutáneas Estafilocócicas/metabolismo , Infecciones Cutáneas Estafilocócicas/microbiología , Infecciones Estreptocócicas/genética , Infecciones Estreptocócicas/inmunología , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/genética , Streptococcus pyogenes/inmunología , Estreptolisinas/genética , Estreptolisinas/inmunología , Virulencia/genética , Virulencia/inmunología , Factores de Virulencia/genética , Factores de Virulencia/inmunología , Factores de Virulencia/metabolismoRESUMEN
Antimicrobial peptides are an integral part of innate immunity, and contribute to the protection of human skin from Staphylococcus aureus colonization and infection. We sought to investigate whether the expression of the eccrine sweat-derived staphylocidal antimicrobial peptide dermcidin might influence S. aureus colonization or recurrent skin and soft-tissue infections (SSTIs). Eccrine sweat was collected from 18 patients with recurrent S. aureus SSTIs, 28 patients who were intermittent or permanent S. aureus carriers, and 32 noncarriers. Expression and proteolytic degradation of dermcidin was investigated using ELISA and surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS). We found no significant differences in the overall amount or the proteolytic degradation pattern of dermcidin-derived peptides between healthy noncarriers, intermittent and permanent carriers, and patients with recurrent S. aureus SSTIs. S. aureus colonization or recurrent SSTIs do not seem to be associated with diminished dermcidin expression in eccrine sweat.
Asunto(s)
Péptidos/metabolismo , Infecciones de los Tejidos Blandos/microbiología , Infecciones Cutáneas Estafilocócicas/microbiología , Staphylococcus aureus , Sudor/metabolismo , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infecciones de los Tejidos Blandos/metabolismo , Infecciones Cutáneas Estafilocócicas/metabolismoRESUMEN
In order to investigate the effect of moxifloxacin on survival, lipid peroxidation and inflammation in immunosuppressed rats with soft tissue infection caused by Stenotrophomonas maltophilia, 144 white male Wistar rats were randomized into six groups: Groups A and B received saline or moxifloxacin once per day, respectively; Groups C and D received saline or moxifloxacin twice per day, respectively, and Groups E and F received saline or moxifloxacin three times per day, respectively. Blood samples were taken at 6 and 30 hr after administration of S. maltophilia. Malonodialdehyde (MDA), WBC counts, bacterial tissue overgrowth, serum concentrations of moxifloxacin and survival were assessed. Survival analysis proved that treatment with moxifloxacin every 8 hr was accompanied by longer survival than occurred in any other group. Tissue cultures 30 hr after bacterial challenge showed considerably less bacterial overgrowth in the spleens and lungs of moxifloxacin-treated than in salinetreated animals, but not in their livers. At 6 hr there were no statistically significant differences between groups. However, at 30 hr, MDA concentrations were significantly greater (P = 0.044) and WBC counts significantly lower (P = 0.026) in group D than in group C. No statistically significant variations were observed between the other groups. Moxifloxacin possibly stimulates lipid peroxidation and enhances phagocytosis, as indicated by MDA production and survival prolongation, without being toxic, as indicated by WBC count. Therefore, under the appropriate conditions, moxifloxacin has a place in treatment of infections in immunosuppressed patients and of infections caused by S. maltophilia.
Asunto(s)
Fluoroquinolonas/farmacología , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Infecciones por Bacterias Gramnegativas/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Infecciones de los Tejidos Blandos/tratamiento farmacológico , Infecciones de los Tejidos Blandos/metabolismo , Stenotrophomonas maltophilia , Animales , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Fluoroquinolonas/administración & dosificación , Infecciones por Bacterias Gramnegativas/mortalidad , Huésped Inmunocomprometido , Recuento de Leucocitos , Masculino , Moxifloxacino , Ratas , Infecciones de los Tejidos Blandos/microbiología , Infecciones de los Tejidos Blandos/mortalidadRESUMEN
Clinical results of wound healing dynamics were studied in 60 patients with soft-tissue infection against the background of diabetes mellitus type II. At the same time the study considered indices of intercellular contacts protein tissue expression such as connexin 43 (Cx43) and basic fibroblast growth factor receptors (bFGFR). The basic therapy of biopsy material of wound borders was applied. The reduction of bFGFR expression and the minor growth of Cx43 expression were observed. The pain syndrome proceeded for a long time and there were signs of perifocal inflammation, retard wound healing with granulation tissue. The application of combined method of ozone therapy which included autohemotherapy with ozone and an external management of wound by ozone-oxygen mixture facilitated to considerable shortening of inflammatory phase and regeneration. It was associated with increased Cx43 expression (in 1.9 times) in comparison with initial level and bFGFR was enlarged in 1.7 times to eighth day of postoperative period.
Asunto(s)
Conexina 43/metabolismo , Diabetes Mellitus Tipo 2/complicaciones , Ozono/uso terapéutico , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/metabolismo , Enfermedades Cutáneas Infecciosas , Infecciones de los Tejidos Blandos , Procedimientos Quirúrgicos Operativos/métodos , Vías de Administración de Medicamentos , Femenino , Tejido de Granulación/efectos de los fármacos , Tejido de Granulación/metabolismo , Humanos , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Masculino , Persona de Mediana Edad , Oxidantes Fotoquímicos/uso terapéutico , Atención Perioperativa/métodos , Enfermedades Cutáneas Infecciosas/tratamiento farmacológico , Enfermedades Cutáneas Infecciosas/etiología , Enfermedades Cutáneas Infecciosas/metabolismo , Enfermedades Cutáneas Infecciosas/cirugía , Infecciones de los Tejidos Blandos/tratamiento farmacológico , Infecciones de los Tejidos Blandos/etiología , Infecciones de los Tejidos Blandos/metabolismo , Infecciones de los Tejidos Blandos/cirugía , Resultado del Tratamiento , Cicatrización de Heridas/efectos de los fármacosRESUMEN
Two cases of necrotizing soft tissue infection of the lower extremity were treated concurrently but independently. Multimodal therapy including hip joint disarticulation and hyperbaric oxygen therapy was administered, resulting in opposite outcomes: survival and death. Analysis of the relationships between patient outcome and time-course changes in serum diacron-reactive oxygen metabolites (d-ROMs; an index of oxidative stress), antioxidative potential, and cytokines revealed that serum d-ROMs levels decreased with time, but high serum levels of interleukin-10 (anti-inflammatory cytokine) persisted in the patient who died. These findings may reflect an immunosuppressive status unfavorable to infection prevention. Serum d-ROMs may be a prognostic predictor in necrotizing soft tissue infections.