ABSTRACT
The combination of vancomycin or daptomycin plus ceftaroline has showed synergistic results in vitro. This study aimed to investigate in vitro synergy of vancomycin or daptomycin plus ceftaroline for seven patients with daptomycin non-susceptible Staphylococcus aureus (SA) bacteremia Thirteen isolates from seven patients were evaluated: two methicillin-susceptible and five methicillin-resistant SA infections. All patients were treated with daptomycin and became non-susceptible (minimum inhibitory concentration (MIC) >1 µg/mL) with therapy or had resistant strains initially. Time kill experiments were completed with 0.25 × MIC, 0.5 × MIC, and 0.75 × MIC concentrations. No synergy was seen at 0.25 × MIC. Synergy was observed for 4 isolates with vancomycin plus ceftaroline and with daptomycin plus ceftaroline for 2 isolates at 0.5 × MIC. These results are in accordance with literature that supports synergistic combinations of daptomycin or vancomycin with ceftaroline for SA bacteremia. Daptomycin non-susceptible SA bacteremia presents a treatment challenge.
Subject(s)
Cephalosporins/pharmacology , Daptomycin/pharmacology , Staphylococcal Infections/microbiology , Staphylococcus aureus/drug effects , Vancomycin/pharmacology , Anti-Bacterial Agents/pharmacology , Cephalosporins/administration & dosage , Daptomycin/administration & dosage , Drug Resistance, Multiple, Bacterial , Drug Synergism , Humans , Microbial Sensitivity Tests , Vancomycin/administration & dosage , CeftarolineABSTRACT
BACKGROUND: The clinical utility of patient and environmental surveillance screening for vancomycin-resistant enterococci (VRE) in the postacute care setting has not been definitively clarified. We assessed the longitudinal relationship between patient colonization and room contamination, and we established their association with unfavorable health outcomes. METHODS: Four hundred sixty-three postacute care patients were followed longitudinally from enrollment to discharge for up to 6 months. Multiple body and environmental sites were sampled at regular intervals to establish correlation between environmental contamination and patient colonization and with longer than expected stay, unplanned hospitalization, and infections adjusting for sex, age, race, Charlson's comorbidity index, and physical self-maintenance score. RESULTS: New VRE acquisition was more likely in patients residing in contaminated rooms (multivariable odds ratio [OR] = 3.75; 95% confidence interval [CI], 1.98-7.11) and vice versa (OR = 3.99; 95% CI, 2.16-7.51). New acquisition and new contamination were associated with increased length of stay (OR = 4.36, 95% CI = 1.86-10.2 and OR = 4.61, 95% CI = 1.92-11.0, respectively) and hospitalization (OR = 2.42, 95% CI = 1.39-4.22 and OR = 2.80, 95% CI = 1.52-5.12). New-onset infections were more common with higher VRE burdens (15% in the absence of VRE, 20% when after VRE isolation only on the patient or only in the room, and 29% after VRE isolation in both the patient and the room). CONCLUSIONS: Room contamination with VRE is a risk factor for patient colonization, and both are associated with future adverse health outcomes in our postacute care patients. Further research is warranted to establish whether VRE screening may contribute to better understanding of risk assessment and adverse outcome prevention in postacute care.
ABSTRACT
OBJECTIVES: Methicillin-resistant Staphylococcus aureus (MRSA) blood stream infections (BSI) are a major health care problem accounting for a large percentage of nosocomial infections. The aim of this study was to identify risk factors associated with 30-day mortality in patients with MRSA BSI. METHODS: This was a retrospective study performed in Southeast Michigan. Over a 9- year period, a total of 1,168 patients were identified with MRSA BSI. Patient demographics and clinical data were retrieved and evaluated using electronic medical health records. RESULTS: 30-day mortality during the 9-year study period was 16%. Significant risk factors for 30-day mortality were age, cancer, heart disease, neurologic disease, nursing home residence and Charlson score >3 with Odds Ratio (OR) of 1.03 (CI 1.02-1.04), 2.29 (CI 1.40-3.75), 1.78 (CI 1.20-2.63), 1.65 (CI 1.08-2.25), 1.66 (CI 1.02 - 2.70) and 1.86 (CI 1.18 - 2.95) correspondingly. Diabetes mellitus, peripheral vascular disease (PVD), and readmission were protective factors for 30-day mortality with OR of 0.53 (CI 0.36-0.78), 0.46 (CI 0.26-0.84) and 0.13 (CI0.05 - 0.32) respectively. CONCLUSIONS: Our study identified significant risk factors for 30-day mortality in patients with MRSA BSI. Interestingly, diabetes mellitus, PVD and readmission were protective effects on 30-day mortality. There was no statistically significant variability in 30-day mortality over the 9-year study period.
Subject(s)
Bacteremia/mortality , Methicillin-Resistant Staphylococcus aureus , Staphylococcal Infections/mortality , Aged , Bacteremia/microbiology , Cause of Death , Cross Infection/mortality , Electronic Health Records , Female , Humans , Male , Methicillin Resistance , Middle Aged , Retrospective Studies , Risk FactorsABSTRACT
OBJECTIVES: Vancomycin is the treatment of choice for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia; however, its use has been subject to scrutiny due to failure in severe infections. Ceftaroline fosamil (CPT-F) is approved for MRSA acute bacterial skin and skin structure infections, but not for bloodstream infections. The clinical outcomes of treatment with CPT-F in patients with MRSA bacteremia were evaluated. METHODS: Patients diagnosed with MRSA bacteremia at Henry Ford Hospital in Detroit, Michigan, USA, involving isolates with a vancomycin minimum inhibitory concentration ≥1.0mg/l and susceptible in vitro to CPT-F, were systematically reviewed retrospectively. Ceftaroline fosamil-treated patients were matched with at least two vancomycin- and/or one daptomycin-treated control patient based on age-patients age 65 years or greater or less than 65 years of age. Outcomes evaluated included the duration of hospitalization, duration of therapy, adverse events, relapse, hospital readmission, and death. RESULTS: Thirty consecutive cases of MRSA bacteremia treated with CPT-F during the period May 2011 to June 2013 were identified; these patients were matched to 56 MRSA bacteremia patients treated with vancomycin and 46 MRSA bacteremia patients treated with daptomycin. The primary source of MRSA bacteremia in the cohort treated with CPT-F was endocarditis (n=7, 23%), skin/wound (n=9, 30%), and bone/joint (n=8, 27%). The MRSA bacteremia in those treated with CPT-F was community-acquired in 43% of cases, healthcare-associated in 43%, and hospital-acquired in 13%. The mean length of hospital stay for these patients was 22 days. The overall 30-day mortality rate was 13% (n=4) in CPT-F patients versus 24% (n=11) in daptomycin patients and 11% (n=6) in vancomycin patients (p=0.188). CONCLUSIONS: CPT-F demonstrated comparable clinical outcomes in MRSA bacteremia patients compared with the other agents, especially as salvage therapy.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacteremia/drug therapy , Cephalosporins/therapeutic use , Methicillin-Resistant Staphylococcus aureus/drug effects , Staphylococcal Infections/drug therapy , Bacteremia/microbiology , Daptomycin/pharmacology , Female , Hospitalization , Humans , Length of Stay , Male , Michigan , Microbial Sensitivity Tests , Middle Aged , Retrospective Studies , Salvage Therapy , Staphylococcal Infections/microbiology , Treatment Outcome , Vancomycin/therapeutic use , CeftarolineABSTRACT
In total, 718 consecutive clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates from 2006 to 2010 and 417 clinical meticillin-susceptible S. aureus (MSSA) isolates from mid-2007 to 2010 were evaluated. Isolates were from blood cultures obtained from separate patients in Detroit, MI, and were tested for in vitro susceptibility trends to vancomycin and daptomycin by molecular strain type. The MRSA pulsed-field gel electrophoresis (PFGE) results showed that 290 (40.4%) were USA100, 296 (41.2%) were USA300 and the remaining isolates were non-USA100/300. Vancomycin minimum inhibitory concentrations (MICs) by Etest [mean±standard deviation (S.D.) 1.55±0.26mg/L] in MRSA isolates showed no significant change over the 5-year period within all strain types, whilst daptomycin MICs by Etest (mean±S.D. 0.51±0.25mg/L) showed a significant downward trend across time (r=-0.243; P<0.001), with this trend occurring among all PFGE groups. For MSSA, a significant decrease in MICs to vancomycin was found by Etest (r=-0.160; P=0.001) and conversely a significant increase in daptomycin MICs by Etest was found (r=0.146; P=0.028). The results of this study showed that changes in MIC were not specific to strain molecular type. For vancomycin, there was no change in MRSA MICs and a decrease in MSSA MICs for blood isolates. For daptomycin, MICs decreased in MRSA and increased in MSSA blood isolates over the study period.
ABSTRACT
Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial pneumonia. To characterize pathogen-derived and host-related factors in intensive care unit (ICU) patients with MRSA pneumonia, we evaluated the Improving Medicine through Pathway Assessment of Critical Therapy in Hospital-Acquired Pneumonia (IMPACT-HAP) database. We performed multivariate regression analyses of 28-day mortality and clinical response using univariate analysis variables at a P level of <0.25. In isolates from 251 patients, the most common molecular characteristics were USA100 (55.0%) and USA300 (23.9%), SCCmec types II (64.1%) and IV (33.1%), and agr I (36.7%) and II (61.8%). Panton-Valentine leukocidin (PVL) was present in 21.9%, and vancomycin heteroresistance was present in 15.9%. Mortality occurred in 37.1% of patients; factors in the univariate analysis were age, APACHE II score, AIDS, cardiac disease, vascular disease, diabetes, SCCmec type II, PVL negativity, and higher vancomycin MIC (all P values were <0.05). In multivariate analysis, independent predictors were APACHE II score (odds ratio [OR], 1.090; 95% confidence interval [CI], 1.041 to 1.141; P < 0.001) and age (OR, 1.024; 95% CI, 1.003 to 1.046; P = 0.02). Clinical failure occurred in 36.8% of 201 evaluable patients; the only independent predictor was APACHE II score (OR, 1.082; 95% CI, 1.031 to 1.136; P = 0.002). In summary, APACHE II score (mortality, clinical failure) and age (mortality) were the only independent predictors, which is consistent with severity of illness in ICU patients with MRSA pneumonia. Interestingly, our univariate findings suggest that both pathogen and host factors influence outcomes. As the epidemiology of MRSA pneumonia continues to evolve, both pathogen- and host-related factors should be considered when describing epidemiological trends and outcomes of therapeutic interventions.
Subject(s)
Cross Infection/microbiology , Cross Infection/mortality , Methicillin-Resistant Staphylococcus aureus/pathogenicity , Pneumonia, Staphylococcal/microbiology , Pneumonia, Staphylococcal/mortality , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Bacterial Toxins , Exotoxins , Female , Genotype , Humans , Leukocidins , Male , Methicillin-Resistant Staphylococcus aureus/classification , Methicillin-Resistant Staphylococcus aureus/genetics , Middle Aged , Molecular Typing , Retrospective Studies , Severity of Illness Index , Survival Analysis , Treatment Outcome , Vancomycin Resistance , Virulence Factors/genetics , Young AdultABSTRACT
Methicillin-resistant Staphylococcus aureus (MRSA) USA300 clone is commonly found in the community and is being increasingly reported in the healthcare setting. A retrospective analysis was conducted to compare the epidemiology and outcomes between community-associated (CA) and healthcare-associated (HA) USA300 MRSA infections. The study enrolled 160 subjects with USA300 MRSA infections (47.5% CA-MRSA and 52.5% HA-MRSA). Failure in the HA group was higher (38.1%) compared with the CA group (23.7%) (P=0.05). Predictors of failure included male gender, age, presence of any co-morbidity, coronary artery disease, chronic kidney disease, history of MRSA, previous admission, fluoroquinolone exposure, HA infection and osteomyelitis (PSubject(s)
Anti-Bacterial Agents/therapeutic use
, Community-Acquired Infections/epidemiology
, Cross Infection/epidemiology
, Methicillin-Resistant Staphylococcus aureus/isolation & purification
, Staphylococcal Infections/epidemiology
, Adult
, Bacterial Typing Techniques/methods
, Community-Acquired Infections/drug therapy
, Community-Acquired Infections/microbiology
, Cross Infection/drug therapy
, Cross Infection/microbiology
, Female
, Genotype
, Humans
, Male
, Methicillin-Resistant Staphylococcus aureus/classification
, Methicillin-Resistant Staphylococcus aureus/genetics
, Middle Aged
, Retrospective Studies
, Risk Factors
, Staphylococcal Infections/drug therapy
, Staphylococcal Infections/microbiology
, Treatment Outcome
ABSTRACT
To gain a better understanding of epidemiology of resistance in Staphylococcus aureus, we describe the molecular epidemiology of methicillin-resistant Staphylococcus aureus bloodstream isolates in urban Detroit. Bloodstream isolates from July 2005 to February 2007 were characterized. Two hundred ten bloodstream isolates from 201 patients were evaluated. Patient characteristics were as follows: median age, 54 years; 56% male; and 71% African-American. Seventy-six percent of infections were health care associated, with 55% being community-onset infections and 21% hospital acquired, and 24% were community associated. The most common sources were skin/wound (25%), central venous catheters (24%), unknown source (20%), and endocarditis (9%). Ninety percent and 5% of isolates had a MIC of vancomycin of
Subject(s)
Bacteremia/microbiology , Methicillin Resistance , Molecular Epidemiology , Staphylococcal Infections/microbiology , Staphylococcus aureus/classification , Staphylococcus aureus/drug effects , Adolescent , Adult , Aged , Aged, 80 and over , Anti-Bacterial Agents/pharmacology , Bacteremia/epidemiology , Bacterial Proteins/genetics , Bacterial Typing Techniques , Cluster Analysis , Community-Acquired Infections/epidemiology , Community-Acquired Infections/microbiology , Cross Infection/epidemiology , Cross Infection/microbiology , DNA Fingerprinting , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Female , Genotype , Geography , Humans , Male , Michigan/epidemiology , Microbial Sensitivity Tests , Middle Aged , Staphylococcal Infections/epidemiology , Staphylococcus aureus/genetics , Staphylococcus aureus/isolation & purification , Urban Population , Vancomycin Resistance , Virulence Factors/geneticsABSTRACT
Vancomycin-resistant Enterococcus faecalis coisolated with vancomycin-resistant (VanA) Staphylococcus aureus was found to contain two plasmids, designated pAM830 (45 kb) and pAM831 (95 kb). pAM830, found to be conjugative and closely related to the Inc18 family of broad-host-range conjugative plasmids, encodes resistances to vancomycin (via a Tn1546-like element) and erythromycin; pAM831 encodes resistances to gentamicin, streptomycin, and erythromycin.