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Jordi Rello

Publications and source records attributed to Jordi Rello.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Clinical approach to the patient with ventilator-associated pneumonia].

Ventilator-associated pneumonia (VAP) is the most frequent infection in the intensive care unit. The importance of this entity lies not only in its high incidence but also in the significant mortality it produces. Therefore, a new episode of VAP should be clinically suspected when new or persistent radiological opacity, purulent respiratory secretions and other signs of sepsis (fever and leukocytosis) are present. In these patients, at the very least, tracheal aspirate samples with quantitative culture and direct staining should be immediately obtained, followed by prompt initiation of empirical broad-spectrum antibiotic therapy. The choice of initial antibiotic therapy should be patient-based, taking into account the risk factors associated especially with VAP caused by Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus, because of the high associated mortality. To evaluate resolution of VAP, we analyze various clinical variables (based mainly on resolution of fever and hypoxemia) and microbiologic information. Once the microorganism responsible for VAP has been isolated, antibiotic therapy can be adapted, based on de-escalation, to reduce the emergence of resistant bacteria. Recent studies suggest that shorter antibiotic regimens reduce the emergence of antibiotic-resistant pathogens, cost and adverse events.

Acinetobacter Infections↗
PubMed2005

Influence of renal function on the pharmacokinetics of piperacillin/tazobactam in intensive care unit patients during continuous venovenous hemofiltration.

The pharmacokinetics of piperacillin/tazobactam (4 g/0.5 g every 6 or 8 hours, by 20-minute intravenous infusion) were studied in 14 patients with acute renal failure who underwent continuous venovenous hemofiltration with AN69 membranes. Patients were grouped according to severity (CL(CR) < or =10 mL/min, 10 < CL(CR) < or =50 mL/min, and CL(CR) > 50 mL/min). A noncompartmental analysis was performed. The sieving coefficient (0.78 +/- 0.28) was similar to the unbound fraction (0.65 +/- 0.24) for tazobactam, but it was significantly different (0.34 +/- 0.25) from the unbound fraction (0.78 +/- 0.14) for piperacillin. Extracorporeal clearance was 37.0% +/- 28.8%, 12.7% +/- 12.6%, and 2.8% +/- 3.2% for piperacillin in each group and 62.5% +/- 44.9%, 35.4% +/- 17.0%, and 13.1% +/- 8.0% for tazobactam. No patients presented tazobactam accumulation. In patients with CL(CR) < 50 mL/min, t(%)ss >MIC90 values were 100% for a panel of 19 pathogens, but in those with CL(CR) > 50 mL/min, t(%)ss >MIC90 indexes were 55.5% and 16.6% for pathogens with MIC90 values of 32 and 64. The extracorporeal clearance of piperacillin/tazobactam is clinically significant in patients with CL(CR) > 50 mL/min, in which the risk of underdosing and clinical failure is important and extra doses are required.

Aged↗
PubMed2005

Prevention and diagnosis of ventilator-associated pneumonia: a survey on current practices in Southern Spanish ICUs.

STUDY OBJECTIVES: To assess the implementation of selected ventilator-associated pneumonia (VAP) prevention strategies, and to learn how VAP is diagnosed in the ICUs of Southern Spain. DESIGN: Multicentric survey. SETTING: The ICUs of 32 hospitals of the public health-care system of Southern Spain. PATIENTS OR PARTICIPANTS: Directors of ICUs. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Twenty-eight ICUs (87.5%) returned completed questionnaires. Ventilator circuits were changed every 72 h or longer in 75% of ICUs. Use of heat and moisture exchangers and open endotracheal suction systems were reported in 96% of ICUs. Subglottic secretion drainage was never used, and 57% of ICUs checked endotracheal tube cuff pressure at least daily. Semi-recumbent position was common (93%), and 67.5% of ICUs used frequently noninvasive ventilation. Continuous enteral feeding was reported in all ICUs. Sedative infusions were usually interrupted every day in 11% of ICUs. Seventy-five percent of ICUs had specific guidelines for antibiotic therapy of VAP, but rotation of antibiotics was uncommon (11%). Twenty-nine percent of ICUs diagnosed VAP without microbiological confirmation. The most used technique for microbiologic diagnosis was qualitative culture of endotracheal aspirates (42.8%). The centers with a larger structural complexity reported using VAP therapy guidelines more frequently than the smaller centers, but they did not utilized bronchoscopic techniques for diagnosing VAP. CONCLUSIONS: Common prevention and diagnostic procedures in clinical practice, including large teaching institutions, significantly differed from evidence-based recommendations and reports by research groups of excellence. In addition, our study suggests that clinical practice for preventing and diagnosing VAP is variable and many opportunities exist to improve the care of patients receiving mechanical ventilation.

Critical Care↗
PubMed2005

Ventilator-associated pneumonia: issues related to the artificial airway.

Pooling of contaminated secretions above the cuff of the endotracheal tube predisposes patients to ventilator-associated pneumonia (VAP). Subglottic secretion drainage requires a special endotracheal tube that has a separate lumen that opens in the subglottic region above the tracheal tube. A recent meta-analysis of the 5 randomized clinical trials that evaluated the efficacy of removing these secretions found that this technique significantly reduces the incidence of VAP. One cost-effectiveness analysis showed savings of dollar 4,900 per episode of VAP prevented. Greatest benefit is derived by patients requiring fewer than 10 days of mechanical ventilation and not exposed to antibiotic therapy. Maintaining the intracuff pressure between 25 and 30 cm H2O is mandatory to guarantee effective drainage and safety. While silver-coated endotracheal tubes reduce pseudomonas pneumonia in intubated dogs and delay airway colonization in intubated patients, evaluation of studies with a variety of case mixes is warranted to identify subsets likely to benefit from the technique before it is implemented on a large scale. A patient who has a colonized airway and who undergoes percutaneous tracheotomy has an increased risk of VAP, particularly due to Pseudomonas aeruginosa, in the week following the procedure. As many studies suggest that incidence of VAP is highly dependent on the strategies of airway management, health care workers should be alerted to issues related to the artificial airway.

Animals↗
PubMed2005

Clinical approach to the patient with suspected ventilator-associated pneumonia.

Management of ventilator-associated pneumonia needs to balance the avoidance of unnecessary antibiotic overuse with the provision of adequate initial empiric therapy. A clinical diagnosis based on new pulmonary opacity and purulent respiratory secretions plus other signs of inflammation is valuable in screening for patients with suspected ventilator-associated pneumonia. A rational strategy starts with immediate initiation of adequate antibiotics and collection of respiratory secretions to evaluate the causative organism. As a minimum, an endotracheal aspirate with direct staining and quantitative cultures should be obtained. Overall, the need to choose adequate antibiotics correctly and expeditiously calls for the use of broad-spectrum antibiotics, but the choice should be narrowed quickly in the light of microbiologic information. However, some patients (those who develop an infection within 5 days of hospitalization, those without recent antibiotic exposure, and those without hospitalization in the past 3 months) are at low risk of infection by resistant organisms. In that subset, adequate initial selection could be a non-pseudomonal third-generation cephalosporin, since antibiotics should target usual community-acquired organisms in addition to some Enterobacteriaceae and Staphylococcus aureus. Coverage of methicillin-resistant S. aureus should be limited only to intensive care units with concomitant index cases and to patients under antibiotic exposure. Patients at risk of Pseudomonas aeruginosa (e.g., 1 week of prior hospitalization or chronic obstructive pulmonary disease) require initial use of a combination of piperacilin/tazobactam and ciprofloxacin, or amikacin plus imipenem, meropenem, or an antipseudomonal cephalosporin. If risk of Acinetobacter baumannii exists, one of these agents should be a carbapenem. After 48 hours of therapy, each patient should be re-evaluated based mainly on resolution of hypoxemia and fever plus the initial microbiologic information. Whereas broad-spectrum therapy is initially warranted in many patients, this treatment may be narrowed considerably as culture results identify the causative organism and its sensitivity. Recent data suggest that reducing overall treatment duration to a maximum of 1 week is safe, effective and is less likely to promote the growth of resistant organisms in patients who are clinically improving. Optimal management should be based on a strategy combining early high doses of an effective agent for a short period of time, which is then simplified in the light of microbiologic information.

Anti-Bacterial Agents↗
PubMed2004

Bench-to-bedside review: Therapeutic options and issues in the management of ventilator-associated bacterial pneumonia.

Despite progress in the diagnosis, prevention and therapy for hospital-acquired infections, ventilator-associated pneumonia (VAP) continues to complicate the course of a significant proportion of patients receiving mechanical ventilation. Mortality rates among patients with VAP have been reported to be as high as 72%, and the morbidity associated with VAP is also considerable, adding days to the hospital stay and increasing health care costs. Appropriate initial antimicrobial therapy for patients with VAP has been shown to reduce mortality rates and improve outcomes; therefore, rapid identification of infected patients and timely, accurate selection of effective antimicrobial agents are important clinical goals. The primary organisms responsible for VAP include Enterobacteriaceae, Pseudomonas aeruginosa and Staphylococcus aureus. However, aetiologies differ considerably between intensive care units, and the increase in antibiotic resistance and nosocomial outbreaks worldwide have presented clinicians with a serious dilemma with respect to selecting appropriate empirical therapy. To date, no optimal antimicrobial regimen for the treatment of VAP has been identified, largely because none of the currently marketed antibiotics has a sufficiently extended spectrum of activity to cover all of the potential key pathogens. More active, less toxic antibacterial agents are still needed, in particular to combat problematic pathogens such as multiresistant Gram-negative bacilli and resistant Gram-positive organisms (e.g. methicillin-resistant S aureus).

Anti-Bacterial Agents↗
PubMed2004

C-reactive protein used as an early indicator of infection in patients with systemic inflammatory response syndrome.

OBJECTIVE: To assess the diagnostic value of a single determination of serum C-reactive protein as a marker of sepsis in critically ill patients. DESIGN: Prospective, observational study. SETTING: Intensive care unit of a university hospital. PATIENTS AND PARTICIPANTS: One hundred twenty-five adult patients with systemic inflammatory response syndrome (SIRS) (55 patients without evidence of infection and 70 patients with the diagnosis of sepsis confirmed by documented infection). Twenty-five patients with non-complicated acute myocardial infarctions (AMI) and 50 healthy volunteers were used as controls. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Serum C-reactive protein concentration was measured within the first 24 h of SIRS onset. Healthy subjects, AMI and non-infectious SIRS patients showed lower C-reactive protein median values ([(0.21 [95% confidence intervals (95% CI), 0.21-0.4] mg/dl, 2.2 [95% CI, 2.1-4.9] mg/dl and 1.7 [95% CI, 2.4-5.5] mg/dl, respectively) than patients with sepsis (18.9 [95% CI, 17.1-21.8]), p<0.001. The presence of severe sepsis ( r(s)=0.27; p=0.03), SOFA score ( r(s)=0.25; p=0.03) and arterial lactate ( r(s)=0.24; p=0.04) correlated significantly with C-reactive protein concentrations in sepsis cases. The best threshold value for C-reactive protein for predicting sepsis was 8 mg/dl (sensitivity 94.3%, specificity 87.3%). The area under the receiver-operating characteristic curve for C-reactive protein was 0.94 (95% CI, 0.89-0.98). CONCLUSIONS: Determination of serum C-reactive protein can be used as an early indicator of infection in patients with SIRS.

Adolescent↗
PubMed2004

Benefits of minocycline and rifampin-impregnated central venous catheters. A prospective, randomized, double-blind, controlled, multicenter trial.

OBJECTIVE: To determine the efficacy of minocycline and rifampin-impregnated catheters compared to non-impregnated catheters in critically ill patients. DESIGN: Prospective, randomized, double-blind, controlled, multicenter trial. SETTING: Intensive care units of seven acute-care teaching hospitals in Spain. PATIENTS. Intensive care unit patients requiring triple-lumen central venous catheter for more than 3 days. INTERVENTIONS: At catheter insertion, 228 patients were randomized to minocycline and rifampin-impregnated catheters and 237 to non-impregnated catheters. Skin, catheter tip, subcutaneous segment, hub cultures, peripheral blood and infusate cultures were performed at catheter withdrawal. The rate of colonization, catheter-related bloodstream infection (CRBSI) and catheter-related clinical infectious complications (purulence at the insertion site or CRBSI) were assessed. MEASUREMENTS AND MAIN RESULTS: In the intention-to-treat analysis (primary analysis), the episodes per 1000 catheter days of clinical infectious complications decreased from 8.6 to 5.7 (RR =0.67, 95% CI 0.31-1.44), CRBSI from 5.9 to 3.1 (RR =0.53, 95% CI 0.2-1.44) and tip colonization from 24 to 10.4 (RR =0.43, 95% CI 0.26-0.73). Antimicrobial-impregnated catheters were associated with a significant decrease of coagulase-negative staphylococci colonization (RR =0.24, 95% CI 0.13-0.45) and a significant increase of Candida spp. colonization (RR =5.84, 95% CI 1.31-26.1). CONCLUSIONS: The use of antimicrobial-impregnated catheters was associated with a significantly lower rate of coagulase-negative staphylococci colonization and a significant increase in Candida spp. colonization, although a decrease in CRBSI, increase in 30-day survival or reduced length of stay was not observed.

Anti-Bacterial Agents↗
PubMed2004

Patterns of colonization by Pseudomonas aeruginosa in intubated patients: a 3-year prospective study of 1,607 isolates using pulsed-field gel electrophoresis with implications for prevention of ventilator-associated pneumonia.

OBJECTIVE: To identify routes and patterns of colonization with Pseudomonas aeruginosa in intubated patients to design strategies of prevention for respiratory infection. DESIGN AND SETTING: Prospective and observational study in the 16-bed intensive care unit of a teaching hospital. PATIENTS AND PARTICIPANTS: Ninety-eight intubated patients were investigated over a 3-year period. Those ventilated less than 72 h were excluded. MEASUREMENTS AND RESULTS: Samples from the tap water from each patient's room, stomach, oropharynx, subglottic secretions, trachea, and rectum were collected when the patient was intubated, and then three times per week. Pulsed-field gel electrophoresis was performed to type the strains. We identified 1,607 isolates pertaining to 35 different pulsotypes. Overall 54.2% of patients presented colonization, and tracheal colonization was present in 30.5%. Ten patients had colonization at intubation, and four of these developed ventilator-associated pneumonia (VAP) after a mean of 4+/-2 days. ICU-acquired colonization occurred in 31 patients, and 4 of these developed VAP after a median of 10+/-5 days. P. aeruginosa was isolated from the room's tap water in 62.4% of samples. More than 90% of tap water samples had pulsotypes 1 and 2, which were frequently isolated in the stomach (59%) but were only rarely associated with VAP. CONCLUSIONS: Although colonization/infection with P. aeruginosa in intubated patients tends to be endogenous, exogenous sources should not be ruled out. A combination of early identification (and eradication) of airways colonization by P. aeruginosa plus infection control measures targeted to reduce cross-contamination should be the basis to prevent pulmonary infection.

Aged↗
PubMed2004

Combination antibiotic therapy lowers mortality among severely ill patients with pneumococcal bacteremia.

Retrospective studies have suggested that combination antibiotic therapy for severe bacteremic pneumococcal pneumonia may reduce mortality. We assessed this issue in a prospective, multicenter, international observational study of 844 adult patients with bacteremia due to Streptococcus pneumoniae. The effect of combination antibiotic therapy versus monotherapy on mortality was examined by univariate analyses and by logistic regression models. The 14-day mortality was not significantly different for the two groups. However, among critically ill patients, combination antibiotic therapy was associated with lower 14-day mortality (23.4 versus 55.3%, p = 0.0015). This improvement in survival was independent of country of origin, intensive care unit support, class of antibiotics, or in vitro activity of the antibiotics prescribed. Combination antibiotic therapy improved survival among critically ill patients with bacteremic pneumococcal illness.

Adolescent↗
PubMed2004

Drug-resistant pneumococcal pneumonia: clinical relevance and related factors.

A multicenter study of 638 cases of community-acquired pneumonia due to Streptococcus pneumoniae (SP-CAP) was performed to assess current levels of resistance. Of the pneumococcal strains, 35.7% had an minimum inhibitory concentration (MIC) of penicillin of > or =0.12 microg/mL (3 isolates had an MIC of 4 microg/mL), 23.8% had an MIC of erythromycin of 128 microg/mL, and 22.2% were multidrug resistant. Logistic regression determined that chronic pulmonary disease (odds ratio [OR], 1.44], human immunodeficiency virus infection (OR, 1.98), clinically suspected aspiration (OR, 2.12), and previous hospital admission (OR, 1.69) were related to decreased susceptibility to penicillin, and previous admission (OR, 1.89) and an MIC of penicillin of MIC > or =0.12 microg/mL (OR, 15.85) were related to erythromycin resistance (MIC, > or =1 microg/mL). The overall mortality rate was 14.4%. Disseminated intravascular coagulation, empyema, and bacteremia were significantly more frequent among patients with penicillin-susceptible SP-CAP. Among isolates with MICs of penicillin of > or =0.12 microg/mL, serotype 19 was predominant and was associated with a higher mortality rate. In summary, the rate of resistance to beta -lactams and macrolides among S. pneumoniae that cause CAP remains high, but such resistance does not result in increased morbidity.

Adolescent↗
PubMed2004

Clinical cure and survival in Gram-positive ventilator-associated pneumonia: retrospective analysis of two double-blind studies comparing linezolid with vancomycin.

OBJECTIVE: To assess the effect of baseline variables, including treatment, on clinical cure and survival rates in patients with Gram-positive, ventilator-associated pneumonia (VAP). DESIGN: Retrospective analysis of two randomized, double-blind studies. SETTING: Multinational study with 134 sites. PATIENTS: 544 patients with suspected Gram-positive VAP, including 264 with documented Gram-positive VAP and 91 with methicillin-resistant S. aureus (MRSA) VAP. INTERVENTIONS: Linezolid 600 mg or vancomycin 1 g every 12 h for 7-21 days, each with aztreonam. MEASUREMENTS AND RESULTS: Clinical cure rates assessed 12-28 days after the end of therapy and excluding indeterminate or missing outcomes significantly favored linezolid in the Gram-positive and MRSA subsets. Logistic regression showed that linezolid was an independent predictor of clinical cure with odds ratios of 1.8 for all patients, 2.4 for Gram-positive VAP, and 20.0 for MRSA VAP. Kaplan-Meier survival rates favored linezolid in the MRSA subset. Logistic regression showed that linezolid was an independent predictor of survival with odds ratios of 1.6 for all patients, 2.6 for Gram-positive VAP, and 4.6 for MRSA VAP. CONCLUSIONS: Initial linezolid therapy was associated with significantly better clinical cure and survival rates than was initial vancomycin therapy in patients with MRSA VAP.

Acetamides↗
PubMed2004

Nosocomial lung infections in adult intensive care units.

Nosocomial respiratory tract infections are the leading type of nosocomial infections. Despite the development of new antibiotic therapies, they are associated with an increased morbidity and mortality. Patients with comorbidities are especially predisposed to acquire these infections, as are patients exposed to respiratory therapy. Aspiration of colonized secretions from the oropharynx is the main mechanism of infection development. Barrier techniques to reduce aspiration and antimicrobial agents to alter bacterial flora are important in preventing pneumonia episodes. The initial institution of an adequate antibiotic regimen is a determinant of outcome. Nosocomial pneumonias are often difficult to treat due to antibiotic-resistant bacteria. Antibiotic policies are crucial in avoiding a progression in antibiotic resistance.

Cross Infection↗
PubMed2004

Prospective observational study of bacteremic pneumococcal pneumonia: Effect of discordant therapy on mortality.

STUDY OBJECTIVE: To evaluate the effect of discordant empirical therapy on outcome in bacteremic pneumococcal community-acquired pneumonia. DESIGN: Prospective observational study. SETTING: A 600-bed teaching hospital with a reference area of 400,000 inhabitants. PATIENTS: All patients aged > or =18 yrs with a diagnosis of community-acquired pneumonia whose blood cultures, obtained within the first 48 hrs of hospitalization, demonstrated growth of Streptococcus pneumoniae were included in the study. METHODS: Discordant therapy was defined as failure to administer an antibiotic with in vitro activity against the isolated strain within 24 hrs of hospital admission. The 2002 breakpoints recommended for respiratory infections by the National Committee for Clinical Laboratory Standards were used to classify therapy. RESULTS: A total of 100 patients with bacteremic pneumococcal pneumonia were identified. Penicillin- and macrolide-resistant strains were identified in 29 and 18 cases, respectively. Only two strains had minimum inhibitory concentrations of >2 microg/mL for cephalosporins. Discordant therapy was documented in ten patients, five of whom died. Mortality in patients receiving concordant therapy was 14% (13 of 90). Nursing home residence (odds ratio [OR] = 14.8) and immunocompromise (OR = 11.5) were independently (p <.05) associated with discordant therapy. Risk of discordant therapy was significantly higher (p <.05) when empirical therapy did not include cefotaxime or ceftriaxone (OR = 10.4). Discordant therapy (OR = 27.3), multilobar involvement (OR = 14.2), underlying chronic obstructive pulmonary disease (OR = 9.1), and hospitalization during the previous 12 wks (OR = 7.9) were independently associated (p <.05) with death. The excess mortality for initial discordant therapy was estimated to be 35.6% (95% confidence interval, 3.73-67.4). CONCLUSIONS: Survival in patients with bacteremic community-acquired pneumococcal pneumonia can be improved by avoiding suboptimal therapy. Using the 2002 breakpoints, it is very unlikely that discordant therapy would be given with ceftriaxone or cefotaxime. Clinical outcome is worse in those patients receiving antimicrobial therapy that in vitro testing suggests would be ineffective.

Adolescent↗
PubMed2004

De-escalation therapy in ventilator-associated pneumonia.

OBJECTIVE: To evaluate de-escalation of antibiotic therapy in patients with ventilator-associated pneumonia. DESIGN: Prospective observational study during a 43-month period. SETTING: Medical-surgical intensive care unit. PATIENTS: One hundred and fifteen patients admitted to the intensive care unit with clinical diagnosis of ventilator-associated pneumonia. All the episodes of ventilator-associated pneumonia received initial broad-spectrum coverage followed by reevaluation according to clinical response and microbiology. Quantitative cultures obtained by bronchoscopic examination or tracheal aspirates were used to modify therapy. INTERVENTIONS: : None. MEASUREMENTS AND MAIN RESULTS: One hundred and twenty-one episodes of ventilator-associated pneumonia were diagnosed. Change of therapy was documented in 56.2%, including de-escalation (the most frequent cause) in 31.4% (increasing to 38% if isolates were sensitive). Overall intensive care unit mortality rate was 32.2%. Inappropriate antibiotic therapy was identified in 9% of cases and was associated with 14.4% excess intensive care unit mortality. Quantitative tracheal aspirates and bronchoscopic samples (58 protected specimen brush and three bronchoalveolar lavage) were associated with 32.7% and 29.5% intensive care unit mortality and 29.3% and 34.4% de-escalation rate. De-escalation was lower (p < .05) in the presence of nonfermenting Gram-negative bacillus (2.7% vs. 49.3%) and in the presence of late-onset pneumonia (12.5% vs. 40.7%). When the pathogen remained unknown, half of the patients died and de-escalation was not performed. CONCLUSION: De-escalation was the most important cause of antibiotic modification, being more feasible in early-onset pneumonia and less frequent in the presence of nonfermenting Gram-negative bacillus. The impact of quantitative tracheal aspirates or bronchoscopic techniques was comparable in terms of mortality.

Algorithms↗
PubMed2004

Survey of ferroxidase expression and siderophore production in clinical isolates of Pseudomonas aeruginosa.

Ferroxidase (encoded by the mco gene), a component of a ferrous iron uptake pathway in Pseudomonas aeruginosa, was detected in all of the 35 respiratory clinical isolates surveyed; in contrast, considerable variation in siderophore expression was observed. The ubiquitous expression of this periplasmic ferroxidase suggests that it plays a key role in iron uptake in this opportunistic pathogen.

Ceruloplasmin↗
PubMed2003

Secretion of the toxin ExoU is a marker for highly virulent Pseudomonas aeruginosa isolates obtained from patients with hospital-acquired pneumonia.

Overall, hospital-acquired pneumonia (HAP) caused by Pseudomonas aeruginosa is associated with high attributable mortality. Although the intrinsic virulence of P. aeruginosa undoubtedly contributes to this phenomenon, it is unclear whether all strains share this property or whether only a subpopulation of strains are capable of causing such severe disease. In this study, the virulence of 35 P. aeruginosa isolates obtained from patients with HAP by use of a cytolytic cell-death assay, an apoptosis assay, and a mouse model of pneumonia. The virulence of individual isolates differed significantly from one to another in each of these assays. Increased virulence was associated with the secretion of ExoU, a toxin transported by the P. aeruginosa type III secretion system. Secretion of ExoS or ExoY, 2 other proteins transported by this system, was not consistently associated with increased virulence. Together, these findings suggest that secretion of ExoU is a marker for highly virulent strains of P. aeruginosa.

Animals↗