PURPOSE: Methicillin-resistant Staphylococcus aureus (MRSA) is recognized as an important cause of not only healthcare-associated pneumonia (HCAP) but also community-acquired pneumonia (CAP). We determined the impact of MRSA on differences in clinical characteristics, courses, and outcomes between CAP and HCAP. MATERIALS AND METHODS: We conducted a retrospective observational study on 78 adult patients admitted with MRSA pneumonia at a university-affiliated tertiary hospital between January 2008 and December 2011. We compared baseline characteristics, chest radiographs, treatment outcomes, and drug resistance patterns between the CAP and HCAP groups. RESULTS: Of the 78 patients with MRSA pneumonia, 57 (73.1%) were HCAP and 21 (26.9%) were CAP. MRSA infection history in the previous year (29.8% vs. 14.3%, p=0.244) tended to be more common in HCAP than in CAP. Despite similar Pneumonia Severity Index scores (151 in CAP vs. 142 in HCAP), intubation rates (38.1% vs. 17.5%; p=0.072) and intensive care unit admission (42.9% vs. 22.8%; p=0.095) tended to be higher in the CAP group, while 28-day mortality was higher in the HCAP group (14.3% vs. 26.3%; p=0.368), although without statistical significance. All patients showed sensitivity to vancomycin and linezolid; meanwhile, HCAP patients showed greater resistance to gentamicin than CAP patients (58.3% vs. 16.6%; p=0.037). The median total hospital charges were 6899 American dollars for CAP and 5715 American dollars for HCAP (p=0.161). CONCLUSION: MRSA pneumonia showed significantly differences in baseline characteristics, chest radiographs, treatment outcomes, and medical expenses between HCAP and CAP groups.
Aged ; Community-Acquired Infections/*microbiology ; Female ; Humans ; Male ; Methicillin-Resistant Staphylococcus aureus/*pathogenicity ; Middle Aged ; Pneumonia/*microbiology ; Retrospective Studies

Adolescent ; Humans ; Linezolid ; therapeutic use ; Male ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; pathogenicity ; Pneumonia ; diagnostic imaging ; microbiology ; Vancomycin ; therapeutic use

BACKGROUNDSepsis is one of the main causes of mortality in critically ill patients following progression to septic shock. To investigate the pathophysiologic changes of sepsis, we developed a novel porcine model of septic shock induced by acute respiratory distress syndrome (ARDS) due to methicillin-resistant Staphylococcus aureus(MRSA) pneumonia.

METHODSTwenty-six male Landraces (Lvyuanweiye, Beijing, China) weighing 30 ± 2 kg were divided into four groups: sham group (SH; n = 5); cotton smoke inhalation group (SM; n = 6); MRSA pneumonia group (MR; n = 6); and septic shock group with cotton smoke inhalation + MRSA pneumonia (SS; n = 9). Extensive hemodynamics, oxygen dynamics, and lung function were monitored for 24 h following the injury or until death. Tissues were collected, and histopathology evaluations were carried out.

RESULTSBlood cultures from 6 of 9 animals in the SS group were positive for MRSA. Two hours following the injury, decreased mean arterial blood pressure (60-70 mmHg) and cardiac index (<2 L.min-1.m-2) were observed in the animals in the SS group, while systemic vascular resistance index was increased. The hemodynamic characteristics of septic shock were only observed in the SS group but not significant in the other groups. The PO2/FiO2in the SM and SS groups decreased to 300 and 100, respectively. In the SS group, extravascular lung water index increased to 20 ml/kg, whereas thoracopulmonary compliance decreased to 10 ml/H2O after injury. Deterioration of pulmonary function in the SS group was more serious than the SM and MR groups. Severe lung injury in the SS group was confirmed by the histopathology evaluations. The lung injury confirmed by high-resolution thin-section computed tomography and histopathology in the SS group was more serious than those of other groups.

CONCLUSIONSIn the present study, we developed a novel porcine model of septic shock induced by ARDS due to severe MRSA pneumonia with characteristic hyperdynamic and hypodynamic phases in 24 h, which mimicked the hemodynamic changing of septic shock in human.

Animals ; Disease Models, Animal ; Hemodynamics ; physiology ; Male ; Methicillin-Resistant Staphylococcus aureus ; pathogenicity ; Pneumonia ; microbiology ; pathology ; Respiratory Distress Syndrome, Adult ; complications ; pathology ; Shock, Septic ; etiology ; pathology ; Swine

BACKGROUNDPrevious studies have different viewpoints about the clinical impact of methicillin resistance on mortality of hospital-acquired bloodstream infection (BSI) patients with Staphylococcus aureus (S. aureus). The objective of this study was to investigate the mortality of hospital-acquired BSI with S. aureus in a military hospital and analyze the risk factors for the hospital mortality.

METHODSA retrospective cohort study was performed in patients admitted to the biggest military tertiary teaching hospital in China between January 2006 and May 2011. All included patients had clinically significant nosocomial BSI with S. aureus. Multivariate Logistic regression analysis was used to identify the risk factors for hospital mortality of patients with S. aureus BSI.

RESULTSOne hundred and eighteen patients of more than one year old were identified as clinically and microbiologically confirmed nosocomial bacteraemia due to S. aureus, and 75 out of 118 patients were infected with methicillin-resistant S. aureus (MRSA). The overall mortality of nosocomial S. aureus BSI was 28.0%. Methicillin resistance in S. aureus bacteremia was associated with significant increase in the length of hospitalization and high proportion of inappropriate empirical antibiotic treatment. After Logistic regression analysis, the severity of clinical manifestations (APACHE II score) (odds ratio (OR) 1.22, 95% confidence interval (CI) 1.12 - 1.34) and inadequacy of empirical antimicrobial therapy (OR 0.25, 95%CI 0.09 - 0.69) remained as risk factors for hospital mortality.

CONCLUSIONSNosocomial S. aureus BSI was associated with high in-hospital mortality. Methicillin resistance in S. aureus has no significant impact on the outcome of patients with staphylococcal bacteremia. Proper empirical antimicrobial therapy is very important to the prognosis.

Adult ; Aged ; Cross Infection ; drug therapy ; mortality ; Female ; Hospital Mortality ; Humans ; Male ; Methicillin-Resistant Staphylococcus aureus ; pathogenicity ; Middle Aged ; Retrospective Studies ; Risk Factors ; Staphylococcal Infections ; drug therapy ; mortality

Child ; Community-Acquired Infections ; complications ; microbiology ; Epidural Abscess ; diagnostic imaging ; etiology ; microbiology ; Female ; Humans ; Magnetic Resonance Imaging ; Methicillin-Resistant Staphylococcus aureus ; pathogenicity ; Staphylococcal Infections ; complications ; microbiology

BACKGROUNDCommunity acquired pneumonia (CAP) is one of the most common infectious disease in emergency department. In 2005 the concept of healthcare associated pneumonia (HCAP) was proposed by the ATS/IDSA guidelines. The clinical features and microbiology of HCAP are different from CAP, however, the initial antimicrobial treatment is still controversial. We aimed to compare the clinical efficacy between HCAP patients treated initially with HCAP guideline-concordant antimicrobial agents and those with CAP guideline-concordant antimicrobial agents.

METHODSWe conducted a retrospective observational study on HCAP patients who were admitted to emergency department between December 2011 and December 2012. Patients were divided into 2 groups according to their different initial antimicrobial treatment. We compared clinical features, distribution of pathogen, severity, days and spending on intravenous antimicrobial, length and charge of hospitalization and clinical outcomes, and meanwhile analyzed the clinical efficacy as well.

RESULTSOf the 125 HCAP patients, 55 patients received CAP guideline-concordant antimicrobial agents and 70 received HCAP agents. The major pathogens were Klebsiella pneumoniae, methicillin-resistant staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Escherichia coli. The 2 groups were similar at baseline, including old age, comorbidities, Pneumonia Severity Index scores, APACHE scores, and length of intravenous antimicrobial use and hospitalization duration, and in-hospital mortality. Overall efficacy rate occurred in 70.0% of HCAP agent patients and 50.9% of CAP agent patients (P = 0.029). Antimicrobial charge and total hospital charge for HCAP agent patients were significantly higher than that for CAP agent patients.

CONCLUSIONSInitial treatment of HCAP patients in emergency department with HCAP guideline-concordant antimicrobial could increase clinical efficacy rate, as well as antimicrobial charge and total hospital charge, but was not associated with shortening the length of stay, or lowering in-hospital mortality.

Aged ; Aged, 80 and over ; Anti-Bacterial Agents ; pharmacology ; Emergency Service, Hospital ; Escherichia coli ; pathogenicity ; Female ; Humans ; Klebsiella pneumoniae ; pathogenicity ; Male ; Methicillin-Resistant Staphylococcus aureus ; pathogenicity ; Pneumonia ; drug therapy ; microbiology ; Pseudomonas aeruginosa ; drug effects ; Retrospective Studies

BACKGROUND: Various virulence factors and superantigens are encoded by mobile genetic elements. The relationship between clonal background and virulence factors differs in different geographic regions. We compared the distribution and relationship of spa types and virulence genes among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from a tertiary hospital in 2000-01 and 2007-08. METHODS: In 2000-01 and 2007-08, 94 MRSA strains were collected from 3 intensive care units at a Korean tertiary hospital. We performed spa typing and multiplex PCR for 19 superantigen genes. RESULTS: Relatively frequent spa types were t037 (40.5%), t002, t601, and t2138 in 2000-01, and t2460 (43.9%), t002, t037, t601, t324, and t2139 in 2007-08. We identified 4 novel spa types, 2 of which were designated as t5076 and t5079. Superantigen profiles were closely linked to spa types. For example, sea, sek, and seq superantigen genes were mainly detected in t037 strains. CONCLUSIONS: Major spa types differed depending on study periods, and the distribution of superantigen genes correlated with spa type.
Bacterial Typing Techniques ; DNA, Bacterial/chemistry ; Genotype ; Humans ; Intensive Care Units/statistics & numerical data ; Methicillin-Resistant Staphylococcus aureus/genetics/*isolation & purification/pathogenicity ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; Staphylococcal Infections/microbiology ; Superantigens/genetics ; Virulence/genetics ; Virulence Factors/*genetics

BACKGROUNDColonization with methicillin-resistant Staphylococcus aureus (MRSA) is a risk factor for subsequent invasive MRSA infection, particularly in patients admitted for critical care. The purpose of this study was to investigate the risk factors affecting nasal colonization of MRSA in patients admitted to intensive care units (ICU).

METHODSBetween August 1, 2011 and June 30, 2012, we screened for MRSA nasal colonization in 350 patients by Real-time PCR within 24 hours of admission by means of swab samples taken from the anterior nares. According to the results of PCR, the patients were divided into 2 groups: the positive group with nasal MRSA colonization and the negative group without nasal MRSA colonization. The 31 (8.86%) patients were MRSA positive. The risk factors evaluated included thirteen variables, which were analyzed by t test for continuous variables and χ(2) test for discrete variables. The variables with significance (P < 0.05) were analyzed with stepwise Logistic regression.

RESULTSThere were differences (P < 0.05) in four variables between two groups. The duration of stay in hospital prior to ICU admission in the positive group was (35.7 ± 16.1) days, vs. (4.5 ± 3.1) days in the negative group. The average blood albumin level was (28.4 ± 2.9) g/L in the positive group, vs. (30.5 ± 4.3) g/L in the negative group. Of 31 patients in the positive group, seven had been treated with antibiotics longer than seven days vs. 34 of 319 patients in the negative group. In the positive group, four of 31 patients received treatment with more than two classes of antibiotics prior to admission in ICU, contrasted to 13 of 319 patients in the negative group. Furthermore, stepwise Logistic regression analysis for these four variables indicates that the duration of stay in hospital prior to ICU admission may be an independent risk factor.

CONCLUSIONSMRSA colonization in ICU admission may be related to many factors. The duration of stay in hospital prior to ICU admission is an independent risk factor.

Adult ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents ; therapeutic use ; Female ; Humans ; Intensive Care Units ; Male ; Methicillin-Resistant Staphylococcus aureus ; pathogenicity ; Middle Aged ; Nasal Cavity ; microbiology ; Polymerase Chain Reaction ; Risk Factors ; Staphylococcal Infections ; drug therapy ; Young Adult

This study aimed to develop a guideline for therapeutic drug monitoring (TDM) of vancomycin. We adopted the new guideline definition from the Institute of Medicine (IOM), adhered closely to the six domains of the Appraisal of Guidelines for Research & Evaluation II (AGREE II), and made recommendations based on systematic reviews. We established a Guideline Steering Group and a Guideline Development Group, formulated 12 questions in the form of Population, Intervention, Comparison, Outcome (PICO) and completed a literature search. As far as we know, we will develop the first evidenced-based guideline for vancomycin TDM under the framework of the Grade of Recommendations Assessment, Development and Evaluation (GRADE).
Anti-Bacterial Agents ; administration & dosage ; economics ; pharmacokinetics ; China ; Drug Administration Schedule ; Drug Monitoring ; methods ; Evidence-Based Medicine ; Humans ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; growth & development ; pathogenicity ; Staphylococcal Infections ; drug therapy ; microbiology ; pathology ; Vancomycin ; administration & dosage ; economics ; pharmacokinetics