Dehydrocostus Lactone Attenuates Methicillin-Resistant Staphylococcus aureus-Induced Inflammation and Acute Lung Injury via Modulating Macrophage Polarization

Dehydrocostus lactone (DHL), a natural sesquiterpene lactone isolated from the traditional Chinese herbs Saussurea lappa and Inula helenium L., has important anti-inflammatory properties used for treating colitis, fibrosis, and Gram-negative bacteria-induced acute lung injury (ALI). However, the effects of DHL on Gram-positive bacteria-induced macrophage activation and ALI remains unclear. In this study, we found that DHL inhibited the phosphorylation of p38 MAPK, the degradation of IκBα, and the activation and nuclear translocation of NF-κB p65, but enhanced the phosphorylation of AMP-activated protein kinase (AMPK) and the expression of Nrf2 and HO-1 in lipoteichoic acid (LTA)-stimulated RAW264.7 cells and primary bone-marrow-derived macrophages (BMDMs). Given the critical role of the p38 MAPK/NF-κB and AMPK/Nrf2 signaling pathways in the balance of M1/M2 macrophage polarization and inflammation, we speculated that DHL would also have an effect on macrophage polarization. Further studies verified that DHL promoted M2 macrophage polarization and reduced M1 polarization, then resulted in a decreased inflammatory response. An in vivo study also revealed that DHL exhibited anti-inflammatory effects and ameliorated methicillin-resistant Staphylococcus aureus (MRSA)-induced ALI. In addition, DHL treatment significantly inhibited the p38 MAPK/NF-κB pathway and activated AMPK/Nrf2 signaling, leading to accelerated switching of macrophages from M1 to M2 in the MRSA-induced murine ALI model. Collectively, these data demonstrated that DHL can promote macrophage polarization to an anti-inflammatory M2 phenotype via interfering in p38 MAPK/NF-κB signaling, as well as activating the AMPK/Nrf2 pathway in vitro and in vivo. Our results suggested that DHL might be a novel candidate for treating inflammatory diseases caused by Gram-positive bacteria.

Ventilator-Associated Pneumonia Patients who Do Not Reduce Bacteria from the Lungs have a Worse Prognosis

The authors determined the significance of serial semi-quantitative bronchoalveolar lavage (BAL) culture results in patients undergoing therapy for ventilator-associated pneumonia. A total of 32 patients underwent at least 2 nonbronchoscopic BAL studies. Fourteen patients had methicillin-resistant Staphylococcus aureus(MRSA). Of these, 11 had more than 100 colony-forming units (cfu) of MRSA/mL of BAL from the follow-up BAL. Eighteen patients had an organism other than MRSA, and 7 of these patients had > 100 cfu of bacteria/mL of BAL from the follow-up BAL. Of the 18 patients with > 100 cfu of bacteria/mL of BAL at follow-up, 14 (79%) died, whereas only 5 of 14 (36%) patients who cleared their bacteria at follow-up died within 28 days. The inability to reduce the bacterial burden from the lower respiratory tract within the first few days of therapy for ventilator-associated pneumonia was associated with increased mortality.

Kineret®/IL-1ra blocks the IL-1/IL-8 inflammatory cascade during recombinant Panton Valentine Leukocidin-triggered pneumonia but not during S. aureus infection

OBJECTIVES

Community-acquired Staphylococcus aureus necrotizing pneumonia is a life-threatening disease. Panton Valentine Leukocidin (PVL) has been associated with necrotizing pneumonia. PVL triggers inflammasome activation in human macrophages leading to IL-1β release. IL-1β activates lung epithelial cells to release IL-8. This study aimed to assess the relevance of this inflammatory cascade in vivo and to test the potential of an IL-1 receptor antagonist (IL-1Ra/Kineret) to decrease inflammation-mediated lung injury.

METHODS

We used the sequential instillation of Heat-killed S. aureus and PVL or S. aureus infection to trigger necrotizing pneumonia in rabbits. In these models, we investigated inflammation in the presence or absence of IL-1Ra/Kineret.

RESULTS

We demonstrated that the presence of PVL was associated with IL-1β and IL-8 release in the lung. During PVL-mediated sterile pneumonia, Kineret/IL-1Ra reduced IL-8 production indicating the relevance of the PVL/IL-1/IL-8 cascade in vivo and the potential of Kineret/IL-1Ra to reduce lung inflammation. However, Kineret/IL-1Ra was ineffective in blocking IL-8 production during infection with S. aureus. Furthermore, treatment with Kineret increased the bacterial burden in the lung.

CONCLUSIONS

Our data demonstrate PVL-dependent inflammasome activation during S.aureus pneumonia, indicate that IL-1 signaling controls bacterial burden in the lung and suggest that therapy aimed at targeting this pathway might be deleterious during pneumonia.

Necrotizing pneumonia due to femoral osteomyelitis caused by community-acquired methicillin-resistant Staphylococcus aureus

A chest X-ray of a young healthy African-American man with acute respiratory failure revealed bilateral multiple nodular shadows in the lungs, while community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) was detected in blood and sputum cultures. Magnetic resonance imaging showed osteomyelitis of the left thigh, and computed tomography revealed bilateral cavitary lesions in the chest, indicating necrotizing pneumonia with pulmonary embolism caused by osteomyelitis as a result of infection with CA-MRSA. CA-MRSA should be suspected as a causative agent of severe community-acquired pneumonia, even in Japan, among patients who belong to communities at high risk of CA-MRSA infection.

Post-influenza pneumonia caused by the USA300 community-associated methicillin-resistant Staphylococcus aureus in Korea

Panton-Valentine leukocidin (PVL)-positive USA300 clone has been the most successful community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clone spreading in North America. In contrast, PVL-negative ST72-CA-MRSA has been predominant in Korea, and there has been no report of infections by the USA300 strain except only one case report of perianal infection. Here, we describe the first case of pneumonia caused by the USA300 strain following pandemic influenza A (H1N1) in Korea. A 50-year-old man was admitted with fever and cough and chest radiograph showed pneumonic consolidation at the right lower lung zone. He received a ventilator support because of respiratory failure. PCR for pandemic influenza A (H1N1) in nasopharyngeal swab was positive, and culture of sputum and endotracheal aspirate grew MRSA. Typing of the isolate revealed that it was PVL-positive, ST 8-MRSA-SCCmec type IV. The analysis of the PFGE patterns showed that this isolate was the same pulsotype as the USA300 strain.

Staphylococcal enterotoxin B toxic shock syndrome induced by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA)

We herein report a case of toxic shock syndrome (TSS) associated with the 2009 pandemic H1N1 (pH1N1) influenza virus and a community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection in a 16-year-old Vietnamese girl. Staphylococcal enterotoxin B (SEB) was detected in the patient's serum, and the level of anti-SEB antibodies was found to be elevated. A flow cytometric analysis showed evidence of activated SEB-reactive Vβ3+ and Vβ12+ T cells. These data suggest that the CA-MRSA-induced activation of SEB-reactive T cells may cause TSS in patients with pH1N1 virus infection. Moreover, this is the first report describing immunological confirmation of SEB contributing directly to TSS in a patient fulfilling the diagnostic criteria of TSS.

[Risk factors associated with the presence of pneumonia in patients with brain injury]

INTRODUCTION

Pneumonia in patients with head trauma occurs commonly; however, few data are available to evaluate the effects of the infection on the prognosis.

OBJECTIVE

The incidence and microbiological findings were described, and the associated risk factors were established with the appearance of pneumonia in patients with severe brain trauma.

MATERIALS AND METHODS

A prospective cohort study was conducted that included 39 patients with severe brain trauma and who required mechanical ventilation; initially, none had pneumonia. These patients were observed during a 24-month period in an attempt to discern the principal risk factors associated with the onset of pneumonia.

RESULTS

Pneumonia occurred in 31 (80%) of the 39 patients, and 28 of these presented early pneumonia. The most frequent germ in patients with pneumonia was Staphylococcus aureus with a percentage of the 42.4%. In the multivariate analysis, the single statistically significant risk factor was the presence of hypotension and vasopressor support with a RR = 27.9 (95% CI = 1.0-749.9, p < 0.05). No significant differences in the days of mechanical ventilation or mortality in both groups. The major mortality-associated risk factor in patients with pneumonia was a low Glasgow score at admittance with an OR = 2.19 (95% CI 1.03 - 4.65), p < 0.05.

CONCLUSIONS

The incidence of pneumonia in patients with severe brain trauma is high; however, its appearance does not affect the prognosis. The single significant risk factor was the presence of hypotension and vasopressor support.

[Multiple abscesses in immunocompetent patients caused by Panton-Valentine leukocidin positive Staphylococcus aureus]

We report cases of immunocompetent patients showing multiple abscesses by a Panton-Valentine leukocidin (PVL) positive Staphylococcus aureus. PVL is considered to be an important virulence factor. The most common manifestations by this pathogen are recurrent or multiple abscesses of the skin. Seldom necrotizing pneumonia with high mortality occurs. Even methicillin-resistant PVL positive isolates have been identified in Germany. Only appropriate infection control measures in combination with antimicrobial therapy resulted in successful eradication of this pathogen. Dermatologists should be informed about this specific type of infection and about the appropriate infection control measures.

[Community-acquired Staphylococcus aureus pneumonia following influenza and the choice of empirical antibiotic treatment]

A 30-year-old man presented with community-acquired pneumonia (CAP), directly following influenza. Sputum Gram stain confirmed Staphylococcus aureus pneumonia. Initial empirical antimicrobial therapy did not cover S. aureus. The isolated S. aureus strain contained genes encoding exotoxins, such as Panton-Valentine leukocidin (PVL). This exotoxin is associated with high mortality and methicillin resistance, but in this patient the strain was susceptible to methicillin. The patient died. In the Netherlands the risk of methicillin resistance in PVL-positive S. aureus CAP is low but real. This should be taken into account when selecting empirical treatment, which can include the combination of flucloxacillin and rifampicin. This case report illustrates the difficulty in predicting the causative agent in CAP and highlights the usefulness of the sputum Gram stain. Moreover, clinical awareness and recognition of S. aureus CAP remains essential to the early initiation of directed therapy.

Post operative penicillin-non-susceptible Streptococcus pneumoniae meningitis and septic shock in a child

The authors describe a one-year-old girl with a fronto-ethmoidal encephalomeningocele who developed wound infection, purulent meningitis and septic shock 5 hours after operation. The patient was treated with intravenous ceftazidime and vancomycin empirically. The cerebrospinal fluid (CSF) and eye discharge grew Streptococcus pneumoniae (S. pneumoniae). The minimal inhibitory concentration (MIC) by E-test of penicillin and cefotaxime were 1.0 and 0.38 ug/ml respectively so the antibiotics were switched to cefotaxime 300 mg/kg/day. She recovered completely after appropriate treatment. Penicillin-non-susceptible S. pneumoniae should be considered as one of the causes of post-operative serious infection of the face and neck in the era of increasing prevalence of penicillin-resistant S. pneumoniae.

Methicillin-resistant Staphylococcus aureus pneumonia after thoracic surgery: successful treatment with linezolid after failed vancomycin therapy

We describe 3 patients with methicillin-resistant Staphylococcus aureus, hospital-acquired pneumonia who demonstrated a microbiological and clinical failure with vancomycin despite adequate trough levels. All 3 patients were cured with linezolid.

Attributable cost of methicillin resistance: an issue that is difficult to evaluate

Estimating the consequences and the cost of methicillin resistance is a difficult challenge. Patients who develop methicillin-resistant ventilator-associated pneumonia (VAP) are very different from those who develop methicillin-sensitive VAP, and biased estimates are frequent. We reviewed some important confounding factors of which the reader should be aware.

Successful salvage therapy with tigecycline after linezolid failure in a liver transplant recipient with MRSA pneumonia

Pulmonary infections are a significant cause of morbidity and mortality after liver transplantation. Infections with methicillin-resistant Staphylococcus aureus (MRSA) have increased in the last 10 years. Mortality may exceed 80% in liver transplant recipients who develop MRSA pneumonia. A 57-year-old male following living-donor liver transplantation developed a right-sided MRSA pneumonia 6 weeks after transplantation, which required artificial ventilation for 14 weeks. Initially, pneumonia was treated with linezolid. However, after 12 days under current therapy, the infection spread out to both lungs. At that time. we initiated the treatment with tigecycline. Under this therapy, the patient could be cured from MRSA pneumonia and was extubated. We detected no tigecycline related hepatotoxic effect. In conclusion, this case suggests that tigecycline may be useful in the salvage therapy of pneumonia due to MRSA after linezolid failure.

Hospital-acquired pneumonia in the 21st century: a review of existing treatment options and their impact on patient care

Hospital-acquired pneumonia is a common nosocomial infection, with significant morbidity and mortality, and represents a major therapeutic challenge to clinicians. The therapeutic approach must be patient-oriented and institution-specific. The specific risk factors of each patient, such as previous antibiotic exposure, underlying diseases, length of hospital stay and the local patterns of antimicrobial resistance, should guide physicians in their decision of the initial optimal empirical therapy. Delays in the initiation or inappropriate/inadequate initial therapy are related to increased mortality and worse outcomes. In responding patients, as soon as culture data are available, efforts should be made to change the initial broad spectrum antibiotic regimen to a more targeted one (de-escalation). The optimal duration of treatment is a matter of debate, but courses longer than 1 week are rarely justified.

Fatal bacteraemic pneumonia due to community-acquired methicillin-resistant Staphylococcus aureus

The recent worldwide surge in the incidence of fatal pneumonia caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has generated renewed interest in this well-known organism. We describe two cases of fulminant bacteraemic pneumonia due to CA-MRSA at the National University Hospital in Singapore and provide further epidemiological descriptors of this potentially-deadly disease. The first patient was an 83-year-old woman while the second was a 71-year-old man, none of whom had risk factors for hospital-acquired MRSA colonisation. Clinicians should be aware of the possibility of severe community-acquired pneumonia caused by this organism. Adequate empirical antimicrobial coverage for this important pathogen should be considered.

Community-associated methicillin-resistant Staphylococcus aureus causing chronic pneumonia

A young woman presented with pneumonia of a 3-month duration with predominantly nodular pulmonary infiltrates. Methicillin-resistant Staphylococcus aureus was identified in multiple cultures of sputum specimens. According to findings of pulsed-field gel electrophoresis, the isolate was identical to USA 300 and carried a type IV Staphylococcus cassette chromosome mec type IV gene and the genes for Panton-Valentine leukocidin.

Suspected ventilator-associated pneumonia in cardiac patients admitted to the coronary care unit

OBJECTIVE

To determine the incidence, risk factors, associated pathogens, and outcome of ventilator-associated pneumonia (VAP) in patients admitted to a coronary care unit (CCU).

PATIENTS AND METHODS

This retrospective cohort study was performed in the CCU of a single tertiary medical center. Patients who were admitted to the CCU between March 23, 2002, and May 25, 2003, and who required invasive mechanical ventilation for more than 48 hours were included.

RESULTS

Of the 92 patients who met the study criteria, 17 (18.5%; 95% confidence interval, 11.9%-27.6%) developed VAP. The incidence of VAP was 36.3 (95% confidence interval, 21.1-58.1) per 1000 days of mechanical ventilation. There were no statistically significant differences in demographics, presence of chronic obstructive pulmonary disease, or use of continuous intravenous sedatives or neuromuscular blockers between patients with and without VAP. The most commonly isolated organisms were methicillin-sensitive Staphylococcus aureus, Sphingomonas paucimobilis, and Stenotrophomonas maltophilia. The median length of stay in the CCU for patients with VAP was 10 days compared to 6 days for patients without VAP (P < .01). Eight (47%) of the 17 patients with VAP died compared to 29 (39%) of 75 patients without VAP (P = .52).

CONCLUSIONS

The incidence of VAP in the CCU is similar to or higher than that reported in other intensive care units. The development of VAP in CCU patients is associated with a prolonged CCU stay but not with an increased hospital mortality.

Is Methicillin Resistance Associated with a Worse Prognosis in Staphylococcus aureus Ventilator-Associated Pneumonia?

BACKGROUND

Excess mortality associated with methicillin resistance in patients with Staphylococcus aureus ventilator-associated pneumonia (SA-VAP), taking into account such confounders as treatment adequacy and time in the intensive care unit (ICU), have not been adequately estimated.

METHODS

One hundred thirty-four episodes of SA-VAP entered in the Outcomerea database were studied. Patients from whom methicillin-resistant S. aureus (MRSA) was recovered were compared with those from whom methicillin-susceptible S. aureus (MSSA) was recovered, stratified for duration of stay in the ICU at the time of VAP diagnosis and adjusted for confounders (severity at admission, characteristics at VAP diagnosis, and treatment adequacy).

RESULTS

Treatment was adequate within 24 h after VAP diagnosis for 86% of the 65 MSSA-infected patients and 77% of the 69 MRSA-infected patients (P = .2). Polymicrobial VAP was more commonly associated with MSSA than with MRSA (49.2% vs. 25.7%; P = .01). MRSA infection was associated with a lower prevalence of coma at hospital admission and a higher rate of use of central venous lines and fluoroquinolones during the first 48 h of the ICU stay. The rates of shock, recurrence, and superinfection were similar in both groups. The crude hospital mortality rate was higher for MRSA-infected patients than for MSSA-infected patients (59.4% vs. 40%; P = .024). This difference disappeared after controlling for time in the ICU before VAP and parameters imbalanced at ICU admission (odds ratio [OR], 1.23; 95% confidence interval [CI], 0.49-3.12; P = .7) and remained unchanged after further adjustments for initial treatment adequacy and polymicrobial VAP (OR, 0.98; 95% CI, 0.36-2.66).

CONCLUSIONS

Differences in patient characteristics, initial ICU treatment, and time in the ICU confounded estimates of excess death due to MRSA VAP. After careful adjustment, methicillin resistance did not affect ICU or hospital mortality rates.

Abszedierende Pneumonie bei einer nierentransplantierten Patientin

A 39-year old female patient who was kidney transplanted three years ago was admitted to hospital with fever of unknown origin for several days. Blood samples revealed decreased renal function and increased inflammation parameters. Chest X-ray and CT scan showed multiple cavernous structures, some with liquid. Staphylococcus aureus was detected in blood culture samples. With the aid of these results Staphylococcus pneumonia with multiple abscesses was diagnosed. The treatment consisted of removal of the infectious focus and a systemic antibiotic therapy corresponding to the microbiologic results. We describe a case of Staphylococcus pneumonia caused by a infected vascular prosthesis under consideration of immunosuppression in a renal transplanted patient.

The effect of vitamin E on secondary bacterial infection after influenza infection in young and old mice

Mortality from influenza is high in the elderly. Deaths are mainly due to secondary complications, including Staphylococcus aureus (SA) infections. Vitamin E (E) supplementation reduces influenza in aged mice. This study determined the efficacy of E supplementation on secondary bacterial infections after influenza in young and old mice. C57BL/6 mice were fed diets containing 30 or 500 ppm E for 4 weeks. Priming with influenza significantly increased SA in the lungs of infected mice fed control diet. Age did not have a significant effect on SA infection alone or SA infection after influenza infection. E supplementation did not have a significant effect on SA infection alone. However, E supplementation abolished the priming effect of influenza on SA.

Methicillin-resistant Staphylococcus aureus infections in ICU patients

The incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections in patients admitted to the intensive care unit has dramatically increased in recent years, with an associated increase in morbidity and mortality and the costs of caring for patients with MRSA infections. Although indiscriminate and inappropriate use of antibiotics has contributed to this phenomenon, horizontal transmission of MRSA between patients and health care providers is the principal cause of this observed increase. This article discusses the pathogenesis, epidemiology, treatment, and prevention of MRSA infections in critically ill patients.

Impact of Methicillin Resistance on Outcome ofStaphylococcus aureusVentilator-associated Pneumonia

The impact of methicillin resistance on morbidity and mortality of patients suffering from severe Staphylococcus aureus infections remains highly controversial. We analyzed a retrospective cohort of 97 patients with methicillin-susceptible and 74 patients with methicillin-resistant Staphylococcus aureus ventilator-associated pneumonia (VAP). Initial empiric antibiotic therapy was appropriate for every patient. Patients with methicillin-resistant Staphylococcus aureus VAP were older, had higher disease-severity scores, and had been on mechanical ventilation longer at onset of VAP. Factors associated with 28-day mortality retained by multivariate logistic regression analysis were: age (odds ratio [OR] = 1.05, 95% confidence interval [CI], 1.02-1.08, p = 0.001) and Day 1 organ dysfunctions or infection (ODIN) score (OR = 1.90, 95% CI, 1.31-2.78, p = 0.001), but not methicillin resistance (OR = 1.72, 95% CI, 0.73-4.05, p = 0.22). The percentages of infection relapse or superinfection did not differ significantly between the two patient groups. In conclusion, after controlling for clinical and physiologic heterogeneity between groups, methicillin resistance did not significantly affect 28-day mortality of patients with Staphylococcus aureus VAP receiving appropriate antibiotics.

Early onset pneumonia: risk factors and consequences in head trauma patients

BACKGROUND

Early onset pneumonia occurs frequently in head trauma patients, but the potential consequences and the risk factors of this event have been poorly studied.

METHODS

This prospective observational study was undertaken in the surgical intensive care unit of a university teaching hospital in Clichy, France. Head trauma patients requiring tracheal intubation for neurologic reasons and ventilation for at least 2 days were studied to assess the risk factors and the consequences of early onset pneumonia.

RESULTS

During a 2-yr period, 109 head trauma patients were studied. The authors found an incidence of early onset pneumonia of 41.3%. Staphylococcus aureus was the most common bacteria involved in early onset pneumonia. Patients with early onset pneumonia had a lower worst arterial oxygen tension:fraction of inspired oxygen ratio, more fever, more arterial hypotension, and more intracranial hypertension, factors known to worsen the neurologic prognosis of head trauma patients. Nasal carriage of S. aureus on admission (odds ratio, 5.1; 95% confidence interval, 1.9-14.0), aspiration before intubation (odds ratio, 5.5; 95% confidence interval, 1.9-16.4) and barbiturate use (odds ratio, 3.9; 95% confidence interval, 1.2-12.8) were found to be independent risk factors of early onset pneumonia.

CONCLUSIONS

The results suggest that early onset pneumonia leads to secondary injuries in head-injured patients. Nasal carriage of S. aureus, aspiration before intubation, and use of barbiturates are specific independent risk factors for early onset pneumonia and must be assessed to find and evaluate strategies to prevent early onset pneumonia.

Linezolid for treatment of ventilator-associated pneumonia: A cost-effective alternative to vancomycin*

OBJECTIVES

To determine the incremental cost-effectiveness of linezolid compared with vancomycin for treatment of ventilator-associated pneumonia due to Staphylococcus aureus.

DESIGN

Decision model analysis of the cost and efficacy of linezolid vs. vancomycin for treatment of ventilator-associated pneumonia. The primary outcome was the incremental cost-effectiveness of linezolid in terms of cost per added quality-adjusted life-year gained. Other outcomes were the marginal costs per hospital survivor and per year of life saved generated by using linezolid. Model estimates were derived from prospective trials of linezolid for ventilator-associated pneumonia and from other studies describing the costs and outcomes for ventilator-associated pneumonia.

SETTING AND PATIENTS

Hypothetical cohort of 1,000 patients diagnosed with ventilator-associated pneumonia.

INTERVENTIONS

In the model, patients received either linezolid or vancomycin.

MEASUREMENTS AND MAIN RESULTS

The incremental cost-effectiveness of linezolid was calculated as the additional quality-adjusted life-years resulting from therapy with linezolid divided by the sum of the incremental costs arising because of use of linezolid (e.g., higher direct costs for linezolid, costs per in-hospital care of survivors, and posthospitalization costs). Despite its higher cost, linezolid was cost-effective for treatment of ventilator-associated pneumonia. The cost per quality-adjusted life-year equals approximately 30,000 dollars. The model was moderately sensitive to the estimated efficacy of linezolid over vancomycin. Nonetheless, even with all inputs simultaneously skewed against, linezolid remains a cost-effective option (cost per quality-adjusted life-year approximately 100,000 dollars). Based on Monte Carlo simulation, the results of our analysis are robust across a range of model inputs and assumptions (95% confidence interval for cost per quality-adjusted life-year ranges from 23,637 dollars to 42,785 dollars).

CONCLUSIONS

Linezolid is a cost-effective alternative to vancomycin for the treatment of ventilator-associated pneumonia.

[Efficacy and safety of cefoperazone/sulbactam in the treatment of children with mucoviscidosis during exacerbation of the bronchopulmonary process]

The use of cefoperazone/sulbactam in combination with amikacin in the treatment of 20 patients with mucoviscidosis and exacerbation of bronchopulmonary pathological process resulted in marked positive dynamics of the clinical and functional indices of the lungs state. The bacteriological effect with respect to the main pathogens in the cases of mucoviscidosis was strain-dependent: eradication of 10 (83.4%) out of 12 Staphylococcus aureus strains and only 3 (15.8%) out of 19 Pseudomonas aeruginosa strains. The most frequent adverse reaction was diarrhea (5 children) successfully corrigated by loperamide. Discontinuation of the drug use was required in 3 patients because of macrohematuria (1 child) and allergic eruption.

Clinical analysis of patients requiring long-term mechanical ventilation of over three months: ventilator-associated pneumonia as a primary complication

OBJECTIVE

To evaluate the clinical features, etiology, and prognosis of patients who required long-term mechanical ventilation (LMV) of over three months for respiratory failure following underlying disease, and observation of their clinical course until death.

PATIENTS

Thirty-seven patients (27 males, 10 females) treated in the internal and medical intensive care unit at Kawasaki Medical School Kawasaki Hospital over the 16-year period from April 1985 to March 2001 were retrospectively studied.

RESULTS

Many of these patients were elderly males with respiratory disease such as pulmonary emphysema or old pulmonary tuberculosis, which had developed into acute respiratory failure resulting in respiratory tract infection and initiation of mechanical ventilation. The survival rates of one year, three years and five years after the start of mechanical ventilation were 60%, 30%, and 16%, retrospectively, and the prognoses were poor. Respiratory tract infection was the most common and serious complication. Specifically, ventilator-associated pneumonia (VAP) was a complication in 21 patients and also the main-cause of death. VAP was observed 2.3 years after the initiation of mechanical ventilation with significant differences in the following risk factors being observed between VAP (+) and VAP (-) groups: chronic obstructive pulmonary disease, duration of mechanical ventilation, prior antibiotics, aspiration of gastric contents and use of histamine-type II receptor antagonist. The causative pathogens of VAP were Pseudomonas aeruginosa and Staphylococcus aureus, which were frequently isolated from tracheal aspirates. All patients with VAP caused by MRSA died shortly after contracting the infection.

CONCLUSIONS

This study has demonstrated that appropriate treatment for respiratory tract infections such as VAP and the prevention of nasocomial infection due to MRSA is of paramount importance for patients requiring long-term mechanical ventilation of over three months.

Influence on outcome of ventilator-associated pneumonia in multiple trauma patients with head trauma treated with selected digestive decontamination

OBJECTIVE

Ventilator-associated pneumonia is said to be associated with an increased mortality or a prolonged intensive care unit stay. In multiple trauma, the use of selective digestive decontamination has been reported to decrease morbidity and mortality associated with pneumonia. We performed a study to evaluate the attributable morbidity and mortality of ventilator-associated pneumonia in multiple trauma patients with head trauma treated with selective digestive decontamination.

DESIGN

Prospective, matched-paired, case-control study.

SETTING

Intensive care unit at a tertiary university hospital.

PATIENTS

During a 6-yr period, 324 consecutive multiple trauma patients with head trauma requiring mechanical ventilation for >48 hrs were prospectively followed for the development of VAP. Case-control matching criteria were as follows: 1) age difference within 5 yrs, 2) Glasgow coma scale within five categories, 3) injury severity score within 5 points, 4) APACHE II score within 5 points, 5) ventilation of control patients for at least as long as the cases. The selective digestive decontamination regimen was used in all patients (cases and controls): polymixin E, gentamicin, and amphotericin B. Systemic cefazolin (1 g three times a day) was given for the first 3 days of intensive care unit stay.

MEASUREMENTS AND MAIN RESULTS

Analysis was performed on 58 pairs that were matched with 100% of success The most common isolates recovered were Staphylococcus aureus (39%) and Haemophilus influenzae (22%). High-risk pathogens were rarely isolated: Pseudomonas aeruginosa (5.1%), Acinetobacter species (8.6%), and methicillin-resistant S. aureus (6.7%). The duration of mechanical ventilation and intensive care unit stay were increased in case patients (11.6 +/- 1.7 and 22.7 +/- 2.9 days, respectively) compared with control patients (9.4 +/- 1.3 and 16.8 +/- 2.9 days, respectively; p <.0006). Mortality was similar in both case (17%) and control (24%) patients.

CONCLUSION

Ventilator-associated pneumonia did not seem to increase mortality of multiple trauma patients with head trauma who received selective digestive decontamination. Whether or not this conclusion applied to trauma patients not receiving selective digestive decontamination should be evaluated in further studies.

[Severe staphylococcal pneumonia in children]

Between 1986 and 1999, 8 cases of severe pneumonia due Staphylococcus aureus strains producing the Panton and Valentine leukotoxin (PVL) were referred to the French reference centre for staphylococcal toxaemia. All but one patient were children and to determine the clinical features of these pneumonia we conducted a prospective surveillance during 1999. Staphylococcal pneumonia was defined according to usual standards. All the strains were tested for the gene coding PVL, the cases associated with PVL positive strains were considered as study group. Nosocomial pneumonia were excluded. 52 cases were referred and 16 were PVL positive. These pneumonia occurred in younger patients (median age = 14.8 vs. 70.1) which were previously healthy (40% of underlying disease in control) Remarkable features were the presence of viral infection in the preceding day (75% vs. 9%), the frequency of shock (81% vs. 53%), respiratory distress (75% vs. 53%) and hemoptysia (38% vs. 3%). Leucopenia was present in 79% of cases. Mortality was higher in the PVL group (75% vs. 47%). Severe staphylococcal pneumonia with shock, leucopenia, hemoptysia and high mortality rate have been previously described in children and young adults. We established the relationship between this syndrome and the PVL production by S. aureus. We believe that viral infection constitute the prerequisite altering the respiratory epithelium which secondary allows S. aureus invasion. The necrotizing action of the PVL leads to the massive haemorrhagic necrotic pneumonia. Staphylococcal necrotizing pneumonia is a new entity which frequency is probably underestimated. Further studies are needed to determinate the prognosis factors, the role of S. aureus carriage and of viral infections. The description of this new syndrome could lead to changes in the management of staphylococcal pneumonia in children.

Hyperimmunoglobulinaemia E syndrome: pulmonary imaging features

Hyperimmunoglobulinaemia E (hyper-IgE) syndrome (Job's syndrome) is a rare disease that presents with recurrent cutaneous and sinopulmonary infections, and which begins in infancy and is associated with extreme hyper-IgE. The pulmonary imaging features typically consist of recurrent alveolar lung infections, pneumatocoeles and, occasionally, pneumothorax. Various other causes of pneumatocoeles in children can be excluded on the basis of clinical history and other data. Computed tomography may add valuable information for the management of these patients.

Pulmonary complications in patients with staphylococcal sepsis

BACKGROUND

The aim of the present study was to determine the pulmonary findings in patients with sepsis caused by Staphylococcus aureus.

METHODS

The clinical and laboratory findings of 32 cases (82%) of pulmonary involvement (secondary pneumonia) of 39 patients with sepsis caused by S. aureus were studied retrospectively. The criteria for the diagnosis of sepsis were clinical evidence of infection plus hyperthermia/hypothermia, tachycardia, tachypnea and white blood cell abnormalities. Secondary pneumonia was diagnosed in patients who presented with staphylococcal disease at one or more non-pulmonary sites and who developed radiologic evidence of pulmonary involvement during the course of illness.

RESULTS

Of the 32 patients, 23 were male and nine were female; the male to female ratio was 2.5/1. The ages of the patients ranged from 2 months to 14 years (7.87 +/- 4.71 years). Bronchopneumonic infiltration was bilateral in 18 patients and unilateral in 14 patients (20 patients (62.5%) had lobar consolidation). Pleurisy was noted in 12 (37.5%) patients; it was on the right side in five patients, on the left in five patients and bilateral in two patients. In contrast, pneumatocele and pneumothorax were observed in seven (21.9%) and four (12.5%) patients, respectively. Closed chest tubes were placed through a closed thoracotomy in five children who developed dyspnea, orthopnea with imminent respiratory failure and mediastinal shift. As well as the pulmonary involvement, arthritis was noted in 13 patients, osteomyelitis in 11 patients, rash in six patients, pericarditis in five patients and renal failure in one patient. Staphylococcus aureus was isolated from blood culture in all except for seven cases. While S. aureus was isolated from blood culture in all of the 12 patients with pleurisy, it was isolated from pleural fluid in only two (16.6%) patients. Six of 32 patients died; the mortality rate was 18.75%.

CONCLUSIONS

It was found that the rate of pulmonary involvement was as high as 82% in sepsis caused by S. aureus, and the pulmonary findings, including bronchopneumonic infiltration and lobar consolidation, were frequently seen in S. aureus pneumonia, causing a mortality rate of 18.75%.

Moderate-dose intravenous immunoglobulin treatment of Job's syndrome. Case report

Job's syndrome (or hyperimmunoglobulinemia E syndrome) is a rare genetic disease characterized by skin eczema, pyogenic "cold" abscesses, sinopulmonary recidivous infections and high IgE plasma concentrations. Job's syndrome treatment is not satisfactory and cases studied are still limited. To describe the effects of IVIG therapy in a 37-year-old woman with hyper IgE syndrome and pneumonia. We measured IgE serum by immuno-fluorometric test and neutrophil chemotaxis by migration in a Boyden chamber before and after IVIG therapy. A moderate dose of IVIG resolved the clinical-radiological signs of the S. aureus bronchopneumonia and improved cytologic and biohumoral parameters. Intravenous immunoglobulins represent a useful treatment for acute pneumonia in Job's syndrome.

Factors affecting the course and severity of transnasally induced Staphylococcus aureus pneumonia in mice

In order to examine several factors that may affect the course and severity of transnasally induced Staphylococcus aureus pneumonia in mice, bacteria were prepared in a free suspension or bound to fetal mouse cells. Immunosuppression was induced in five strains of mice (ICR, C57BL/6, BALB/c, C3H/He and CBA/J) by injection of cyclophosphamide (200 mg/kg body weight), 2 days before infection. Impairment of mucociliary clearance was induced by intranasal instillation of formalin. Mice were then infected with various doses and strains of the organism. Although no significant differences were observed between either form of inoculum, pretreatment with formalin plus cyclophosphamide was associated with a significant increase in lung bacterial counts. In particular, cyclophosphamide treatment was associated with a high mortality in mice infected with several strains of S. aureus irrespective of their toxin production profiles. Histopathological examination demonstrated that in mice treated with formalin plus cyclophosphamide, clusters of bacteria were observed in lung parenchyma, associated with a mild accumulation of inflammatory cells at day 2 and extensive cell infiltration at day 7. CBA/J mice represented the most susceptible strain among those examined, with 10(4)- and 10(2)-fold higher bacterial counts in the lungs at days 3 and 5, respectively. These results indicate that neutropenia and impaired mucociliary clearance are major factors that influence the severity of S. aureus pneumonia in mice. Analysis of the role of genetic background in enhancement of vulnerability to infection is warranted in future studies.

Trimethoprim-sulfamethoxazole for the prevention of methicillin-resistant Staphylococcus aureus pneumonia in severely burned patients

BACKGROUND

Patients with severe burns are at increased risk of developing methicillin-resistant Staphylococcus aureus (MRSA) ventilator-associated pneumonia. This study was designed to determine whether MRSA pneumonia can be prevented by prophylactic administration of trimethoprim-sulfamethoxazole (TMP-SMX).

METHODS

We conducted a prospective, randomized, placebo-controlled study in patients with severe burns (> or = 20%), who required ventilator support. Prophylaxis was done with oral TMP-SMX (80 mg/400 mg) three times daily for 10 days from 4 to 6 days after burn injury. The incidence of MRSA pneumonia and the side effects were evaluated during the administration period.

RESULTS

Twenty-one patients were assigned to receive TMP-SMX, and 19 patients to receive placebo. The incidence of MRSA pneumonia was 4.8% in the TMP-SMX group and 36.8% in the placebo group, showing a significant difference (p = 0.017). No major side effects of therapy were seen in the TMP-SMX group.

CONCLUSION

Prophylactic treatment with TMP-SMX can prevent MRSA pneumonia in severely burned patients.

Aetiology of pneumonia following isolated closed head injury

Patients undergoing mechanical ventilation (MV) after an isolated closed head injury (ICHI) have often been found to develop hospital-acquired pneumonia (HAP) well before subjects who require MV for different reasons. In a prospective study of patients receiving MV after an ICHI. 38 subjects (out of 65 with clinically suspected HAP) had a bacteriological diagnosis established on the basis of correspondence between cultures made from bronchoalveolar lavage and protected specimen brush (with quantitative thresholds of 10(4) and 10(3) cfu ml-1, respectively). Patients were separated according to the time of onset of HAP, with 20 subjects who developed HAP within 4 days of the start of MV (early onset pneumonia, EOP) and 18 subjects who developed HAP after the fourth day (late onset pneumonia, LOP). In those who had LOP, an expected spectrum of organisms was found, with Gram-negatives (especially Pseudomonas sp.) accounting for the majority of isolates. However, in EOP cases, Gram-positive bacteria (especially Staphylococcus sp. and Streptococcus pneumoniae) were found to largely predominate (P = 0.0000026). This confirms the high incidence of staphylococcal pneumonia in neurosurgery patients, and also provides evidence that the vast majority of such staphylococcal pneumonia are EOP. Unlike most previous reports, the microbiological findings from the present study suggest that a cut-off point of 4 days successfully distinguishes between EOP and LOP. Since these two clinical entities differ significantly in terms of pathogenesis and aetiology, preventive measures and therapeutical protocols have to be tailored accordingly.

Caval thrombectomy for severe staphylococcal osteomyelitis

Two children are presented in whom thrombosis of the inferior vena cava developed in association with an acute staphylococcal osteomyelitis. One case involved the left femur and the other the left ileum. Both children had diffuse bilateral staphylococcal pneumonia from presumed septic embolization. There were close similarities between their illness and management, except that the child who survived underwent a caval thrombectomy in the acute phase of her illness. It is hypothesized that the thrombectomy played an important role in her recovery.

Clinical spectrum of ventilator-associated pneumonia caused by methicillin-sensitive Staphylococcus aureus

The incidence of tracheal colonization and its association with ventilator-associated pneumonia caused by methicillin-sensitive Staphylococcus aureus (MSSA) was studied prospectively in 530 consecutively admitted mechanically ventilated patients in a general intensive care unit. Furthermore, the clinical spectrum, outcome, and microbiological results of 27 cases of staphylococcal ventilator-associated pneumonia (SVAP) were examined. Ventilator-associated pneumonia was diagnosed by protected specimen brush and/or bronchoalveolar lavage. On admission, 7% of the patients were colonized with MSSA in the trachea. Acquired tracheal colonization was demonstrated in 10% of the patients and occurred less frequently in patients with a hospital stay of > 48 h before ICU admission compared to patients admitted directly to the ICU (6% vs. 15%, p < 0.001). Moreover, colonization was acquired more frequently among trauma and neurological/neurosurgical patients (22%) as compared to surgical and medical patients (7%) (p < 0.0001). Twenty-one patients (4%) developed SVAP, the incident being higher in patients colonized in the trachea with MSSA than in those not colonized (21% vs. 1%), p < 0.00001). Staphylococcal ventilator-associated pneumonia developed more often in trauma and neurological/neurosurgical patients as compared to surgical and medical patients (8% vs. 3%, p < 0.05). Moreover, patients with a hospital stay of < 48 h before admission to the ICU had a higher incidence of SVAP as compared to those with a longer hospital stay before ICU admission (7% vs. 2%, p < 0.01). Crude infection-related mortality was 26%. Preceding colonization with MSSA in the trachea appears to be an important risk factor for the development of SVAP, and patients with a short duration of hospitalization before intensive care unit admission have the highest incidence of ventilator-associated pneumonia caused by MSSA.

Community-acquired pneumonia due to Staphylococcus cohnii in an HIV-infected patient: case report and review

Coagulase-negative staphylococci recently have been implicated as a cause of serious infections in immunocompromised individuals. An unusual case of community-acquired pneumonia due to Staphylococcus cohnii in an HIV-infected drug user is described. Results of a study conducted to examine the prevalence of infection due to Staphylococcus cohnii strains and their antibiotic-sensitivity patterns show a low frequency but a high morbidity. These results and a brief review of the literature emphasize the importance of these organisms and other staphylococcal species as emerging opportunistic pathogens in patients with AIDS.

Lower respiratory tract infections following cardiac arrest and cardiopulmonary resuscitation

All episodes of lower respiratory tract infection that developed among 96 patients surviving for > 24 hours after cardiac arrest were prospectively studied over an 18-month period. Pneumonia developed in 23 (24.0%) of patients after a mean of 7 days (SD, +/- 6.2 days). The development of four superinfections raised the cumulative incidence to 28.1%. Purulent tracheobronchitis was diagnosed in three instances. The causative agent of pneumonia was identified in 18 episodes, three of which were polymicrobial. Gram-positive cocci represented 57.1% of isolates, and Staphylococcus aureus--the most frequently isolated microorganism in this population--accounted for two-thirds of all gram-positive cocci. Pseudomonas aeruginosa was isolated in six episodes, five of which were associated with previous antibiotic use. Nine (39.1%) of the 23 patients in the group with pneumonia died, but only one of these deaths was considered to be directly related to pneumonia. In conclusion, pneumonia is a common complication of patients surviving cardiac arrest, but, with adequate treatment, its influence on outcome is marginal. Gram-positive cocci are the predominant pathogens, although infection with P. aeruginosa should be considered among patients receiving antibiotics.