Left ventricular pseudoaneurysm as a fatal complication of purulent pericarditis.

We report a case of a 48-year-old man with purulent pericarditis by Streptococcus viridans, despite aggressive treatment with antibiotics and partial pericardiectomy was complicated by left ventricle pseudo-aneurysm resulting in a fatal outcome. The case highlights the course of complicated purulent pericarditis and the use of noninvasive imaging for assessing early signs of pseudoaneurysm and its typical progression.

Automated alerts coupled with antimicrobial stewardship intervention lead to decreases in length of stay in patients with gram-negative bacteremia.

OBJECTIVE: To assess the impact of active alerting of positive blood culture data coupled with stewardship intervention on time to appropriate therapy, length of stay, and mortality in patients with gram-negative bacteremia. DESIGN: Quasi-experimental retrospective cohort study in patients with gram-negative bacteremia at the Detroit Medical Center from 2009 to 2011. SETTING: Three hospitals (1 community, 2 academic) with active antimicrobial stewardship programs within the Detroit Medical Center. PATIENTS: All patients with monomicrobial gram-negative bacteremia during the study period. INTERVENTION: Active alerting of positive blood culture data coupled with stewardship intervention (2010-2011) compared with patients who received no formalized stewardship intervention (2009). RESULTS: Active alerting and intervention led to a decreased time to appropriate therapy (8 [interquartile range (IQR), 2-24] vs 14 [IQR, 2-35] hours; P = .014) in patients with gram-negative bacteremia. After controlling for differences between groups, being in the intervention arm was associated with an independent reduction in length of stay (odds ratio [OR], 0.73 [95% confidence interval (CI), 0.62-0.86]), correlating to a median attributable decrease in length of stay of 2.2 days. Additionally, multivariate modeling of patients who were not on appropriate antimicrobial therapy at the time of initial culture positivity showed that patients in the intervention group had a significant reduction in both length of stay (OR, 0.76 [95% CI, 0.66-0.86]) and infection-related mortality (OR, 0.24 [95% CI, 0.08-0.76]). CONCLUSIONS: Active alerting coupled with stewardship intervention in patients with gram-negative bacteremia positively impacted time to appropriate therapy, length of stay, and mortality and should be a target of antimicrobial stewardship programs.

Treatment of methicillin-resistant Staphylococcus aureus infections with a minimal inhibitory concentration of 2 µg/mL to vancomycin: old (trimethoprim/sulfamethoxazole) versus new (daptomycin or linezolid) agents.

BACKGROUND: Guidelines recommend that agents other than vancomycin be considered for some types of infection due to methicillin-resistant Staphylococcus aureus (MRSA) when the minimum inhibitory concentration (MIC) to vancomycin is 2 µg/mL or more. Alternative therapeutic options include daptomycin and linezolid, 2 relatively new and expensive drugs, and trimethoprim/sulfamethoxazole (TMP/SMX), an old and inexpensive agent. OBJECTIVE: To compare the clinical efficacy and potential cost savings associated with use of TMP/SMX compared to linezolid and daptomycin. METHODS: A retrospective study was conducted at Detroit Medical Center. For calendar year 2009, unique adults (age >18 years) with infections due to MRSA with an MIC to vancomycin of 2 µg/mL were included if they received 2 or more doses of TMP/SMX and/or daptomycin and/or linezolid. Data were abstracted from patient charts and pharmacy records. RESULTS: There were 328 patients included in the study cohort: 143 received TMP/SMX alone, 89 received daptomycin alone, 75 received linezolid alone, and 21 patients received a combination of 2 or more of these agents. In univariate analysis, patients who received TMP/SMX alone had significantly better outcomes, including in-hospital (p = 0.003) and 90-day mortality (p < 0.001) compared to patients treated with daptomycin or linezolid. Patients receiving TMP/SMX were also younger (p < 0.001), had fewer comorbid conditions (p < 0.001), had less severe acute severity of illness (p < 0.001), and received appropriate therapy more rapidly (p = 0.001). In multivariate models the association between TMP/SMX treatment and mortality was no longer significant. Antimicrobial cost savings associated with using TMP/SMX averaged $2067.40 per patient. CONCLUSIONS: TMP/SMX monotherapy compared favorably to linezolid and daptomycin in terms of treatment efficacy and mortality. Use of TMP/SMX instead of linezolid or daptomycin could potentially significantly reduce antibiotic costs. TMP/SMX should be considered for the treatment of MRSA infection with MIC of 2 µg/mL to vancomycin.

Predictors and outcomes of linezolid-resistant vancomycin-resistant Enterococcus: a case-case-control study.

Linezolid is an important agent for the treatment of infections because of vancomycin-resistant Enterococcus (VRE). This study identified independent predictors for isolation of linezolid-resistant VRE (LZD-R-VRE) and analyzed outcomes associated with linezolid resistance. Immunosuppression, prior surgery, and previous exposure to ß-lactam antibiotics were independent predictors for isolation of LZD-R-VRE but not for LZD-susceptible-VRE. Prior exposure to linezolid was not a predictor for isolation of LZD-R-VRE.

Efficacy of ertapenem for treatment of bloodstream infections caused by extended-spectrum-ß-lactamase-producing Enterobacteriaceae.

Ertapenem is active against extended-spectrum-ß-lactamase (ESBL)-producing Enterobacteriaceae organisms but inactive against Pseudomonas aeruginosa and Acinetobacter baumannii. Due to a lack of therapeutic data for ertapenem in the treatment of ESBL bloodstream infections (BSIs), group 2 carbapenems (e.g., imipenem or meropenem) are often preferred for treatment of ESBL-producing Enterobacteriaceae, although their antipseudomonal activity is unnecessary. From 2005 to 2010, 261 patients with ESBL BSIs were analyzed. Outcomes were equivalent between patients treated with ertapenem and those treated with group 2 carbapenems (mortality rates of 6% and 18%, respectively; P = 0.18).

Comparison of the clinical characteristics and outcomes associated with vancomycin-resistant Enterococcus faecalis and vancomycin-resistant E. faecium bacteremia.

In published studies, cohorts of patients with bacteremia due to vancomycin-resistant Enterococcus (VRE) have predominantly been infected with Enterococcus faecium. Little is known about the epidemiology and outcomes associated with bacteremia due to VR Enterococcus faecalis. A retrospective study of isolates obtained from January 2008 to October 2010 was conducted at Detroit Medical Center (DMC). Unique patients with blood cultures positive for VRE were reviewed. Outcomes were analyzed using logistic regression. During the study period, 105 cases of bacteremia due to VR E. faecalis and 197 cases of bacteremia due to VR E. faecium were identified. The mean age in the study cohort was 61.5 ± 15 years; 162 subjects (53.6%) were male. After controlling for a propensity score, bacteremia due to VR E. faecalis was associated with >2-fold-lower in-hospital mortality than bacteremia due to VR E. faecium. Interestingly, bacteremia due to VR E. faecalis was associated with longer hospital stay after VRE isolation, although total length of stay was similar for groups with VR E. faecalis and VR E. faecium. Bacteremia due to VR E. faecalis was associated with a >2-fold-lower risk for mortality than bacteremia due to VR E. faecium, possibly due to the availability of ß-lactam therapeutics for treatment of VR E. faecalis.

Group B Streptococcus infections in non-pregnant adults: the role of immunosuppression.

BACKGROUND: Group B Streptococcus (GBS) is a known causative pathogen of neonatal sepsis, but the epidemiology in non-pregnant adults is less studied. METHODS: Retrospective case-control and cohort analyses of risk factors and outcomes of GBS infections among non-pregnant adults were conducted at the Detroit Medical Center from January 2005 to May 2010. Uninfected controls were matched to cases in a 3:1 ratio. Data were obtained from charts and pharmacy records. Identification of the bacteria and antimicrobial susceptibility testing were determined by MicroScan. Cox regression was used for matched multivariate analyses. RESULTS: Thirty-two patients with GBS infections were identified and were matched and compared to 96 controls. Compared to controls, patients with GBS infection were significantly younger. Immunosuppression, attributable mainly to neutropenia and recent use of glucocorticoids, was an independent predictor for GBS infection (odds ratio 2.7, p=0.03). Nine (28%) of the patients with GBS infection had bacteriological failure despite the administration of appropriate antimicrobial therapy. Of the 10 patients with bloodstream infections (BSI), three had endocarditis and four had central nervous system (CNS) infections. During the study period the incidence of infections decreased, but the rates of resistance to erythromycin and clindamycin increased. CONCLUSIONS: GBS, previously considered a genitourinary pathogen, has emerged as a non-nosocomial opportunistic pathogen causing BSI, endocarditis, and CNS infections. Immunosuppression, particularly transient immunosuppressed states, was an independent predictor for GBS BSI. Resistance rates to macrolides and clindamycin continue to increase, and should be closely monitored.

Hospital bath basins are frequently contaminated with multidrug-resistant human pathogens.

The hospital environment is increasingly recognized as a reservoir for hospital-acquired pathogens. During a 44-month study period, a total of 1,103 basins from 88 hospitals in the United States and Canada were sampled. Overall, 62.2% of the basins (at least 1 basin at each hospital) were contaminated with commonly encountered hospital-acquired pathogens.