Publications (137) View all
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Article: Persistent Staphylococcus aureus Bacteremia: A Prospective Analysis of Risk Factors, Outcomes, and Microbiologic and Genotypic Characteristics of Isolates.
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ABSTRACT: Persistent Staphylococcus aureus bacteremia (SAB) that fails to respond to appropriate antibiotic therapy is associated with poor outcomes. Comprehensive prospective studies on risk factors and outcomes of persistent bacteremia are limited. We investigated outcomes and risk factors encompassing clinical, pharmacokinetic, microbiologic, and genotypic characteristics associated with persistent bacteremia using a case-control study nested in a prospective cohort of patients with SAB at a tertiary-care hospital from August 2008 through September 2010. We compared the clinical characteristics, management, and outcomes of patients with persistent bacteremia (≥7 d) with controls with resolving bacteremia (<3 d). To detect associations between microbiologic and genotypic characteristics of methicillin-resistant S. aureus (MRSA) isolates and persistent bacteremia, we determined the heteroresistance phenotype, SCCmec type, agr genotype and functionality, multilocus sequence typing, and presence of 41 virulence genes. Our cohort consisted of 483 patients; 76 (15.7%) had persistent bacteremia, 212 (43.5%) had resolving bacteremia. In the multivariate analysis, independent risk factors associated with persistent bacteremia were community-onset bacteremia (odds ratio [OR], 2.91; 95% confidence interval [CI], 1.24-6.87), bone and joint infection (OR, 5.26; 95% CI, 1.45-19.03), central venous catheter-related infection (OR, 3.36; 95% CI, 1.47-7.65), metastatic infection (OR, 36.22; 95% CI, 12.71-103.23), and methicillin resistance (OR, 16.99; 95% CI, 5.53-52.15). For patients with eradicable foci, delay (>3 d) in the removal of the infection focus was significantly associated with persistent bacteremia (OR, 2.18; 95% CI, 1.05-4.55). There were no significant associations of persistent bacteremia with high vancomycin minimal inhibitory concentration, vancomycin heteroresistance, and microbiologic/genotypic characteristics of MRSA isolates. However, initial vancomycin trough level <15 mg/L was an independent risk factor for persistent MRSA bacteremia (OR, 4.25; 95% CI, 1.51-11.96) in the multivariate analysis. Clinical outcomes were significantly worse for patients with persistent bacteremia. Relapse of bacteremia and attributable mortality within 12 weeks after SAB were significantly higher in patients with persistent bacteremia than in those with resolving bacteremia (9.2% [7/76] vs. 2.4% [5/212], p = 0.02 and 21.1% [16/76] vs. 9.4% [20/212], p = 0.009, respectively).In conclusion, patients with SAB should be given early aggressive treatment strategies, including early source control and maintenance of a vancomycin trough level ≥15 mg/L, to reduce the risk of persistent bacteremia.Medicine 03/2013; 92(2):98-108. · 4.35 Impact Factor -
Article: Efficacy of a strategy for discontinuing pre-emptive ganciclovir therapy after a negative cytomegalovirus antigenaemia test result in seropositive kidney transplant recipients.
Journal of Antimicrobial Chemotherapy 01/2013; · 5.07 Impact Factor -
Article: Is caspofungin really an effective treatment for Pneumocystis jirovecii pneumonia in immunocompromised patients without human immunodeficiency virus infection? Experiences at a single center and a literature review.
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ABSTRACT: Caspofungin, an antifungal agent that acts on the cell wall by inhibiting β-1,3-glucan synthesis, is likely to be effective for treating Pneumocystis pneumonia, because one of the identifying characteristics of Pneumocystis jirovecii is the presence of β-1,3-glucan in its cell wall. Previous case reports in which the efficacy of caspofungin was found to be favourable have supported this hypothesis. However, of 4 HIV-negative patients who received caspofungin as a salvage regimen at Asan Medical Center, none showed a response. Our negative experience opposes the optimistic view of caspofungin use for Pneumocystis pneumonia expressed in previous reports.Scandinavian Journal of Infectious Diseases 01/2013; · 1.72 Impact Factor -
Article: Accessory Gene Regulator (agr) Dysfunction in Staphylococcus aureus Bloodstream Isolates from Korean Patients.
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ABSTRACT: We describe the genetic and microbiological characteristics of methicillin-resistant Staphylococcus aureus (MRSA) bloodstream isolates with agr dysfunction from a tertiary-care hospital in Korea. Of these, ST5-SCCmec type II-agr group II MRSA isolates, which are known to be prevalent in hospital-acquired infections in Korea, were the most abundant, due to clonal spread of a specific agr-defective lineage. This finding suggests that the loss of agr function may confer a potential advantage in a hospital setting. Clonal spread of a specific agr-defective strain was not observed among community-associated MRSA or methicillin-susceptible S. aureus clones, regardless of community or hospital acquisition of infection. agr-defective clones including ST5- and ST239-MRSA were enriched for heteroresistant vancomycin-intermediate S. aureus.Antimicrobial Agents and Chemotherapy 12/2012; · 4.84 Impact Factor -
Article: Treatment Duration of Uncomplicated Staphylococcus aureus Bacteremia to Prevent Relapse: an Analysis of Prospective Observational Cohort Study.
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ABSTRACT: Practice guidelines recommend at least 14 days of antibiotic therapy for uncomplicated Staphylococcus aureus bacteremia (SAB). However, these recommendations have not been formally evaluated in clinical studies. To evaluate the duration of therapy for uncomplicated SAB, we analyzed data from our prospective cohort of patients with SAB. A prospective observational cohort study was performed in patients with SAB at a tertiary-care hospital in Korea between August 2008 and September 2010. All adult patients with SAB were prospectively enrolled and observed over a 12-week period. Uncomplicated SAB was defined as follows: negative results of follow-up blood cultures at 2 to 4 days; defervescence within 72h of therapy; no evidence of metastatic infection; catheter-related bloodstream infection or primary bacteremia without evidence of endocarditis on echocardiography. Of 483 patients with SAB, 111 met the study criteria for uncomplicated SAB. Fifty three (47.7%) had methicillin-resistant SAB. When short-course therapy (<14 days) and intermediate-course therapy (≥14 days) were compared, the treatment failure rate (10/38 [26.3%] versus 16/73 [21.9%]) and crude mortality (7/38 [18.4%] versus 16/73 [21.9%]) did not differ significantly between the two groups. However, short-course therapy was significantly associated with relapse (3/38 [7.9%] versus 0/73, P = 0.036). In multivariate analysis, primary bacteremia was associated with a trend toward increased treatment failure (P = 0.06). Therefore, in the treatment of uncomplicated SAB, it seems reasonable to consider at least 14 days of antibiotic therapy to prevent relapse as practice guidelines recommend. Because of its poor prognosis, primary bacteremia even with a low risk of complication should not be treated with short-course therapy.Antimicrobial Agents and Chemotherapy 12/2012; · 4.84 Impact Factor
