scholarly journals Impact of Reduced Vancomycin MIC on Clinical Outcomes of Methicillin-Resistant Staphylococcus aureus Bacteremia

2013 ◽  
Vol 57 (11) ◽  
pp. 5536-5542 ◽  
Author(s):  
So-Youn Park ◽  
In-Hwan Oh ◽  
Hee-Joo Lee ◽  
Chun-Gyoo Ihm ◽  
Jun Seong Son ◽  
...  

ABSTRACTVancomycin has been a key antibiotic agent for the treatment of methicillin-resistantStaphylococcus aureus(MRSA) infections. However, little is known about the relationship between vancomycin MIC values at the higher end of the susceptibility range and clinical outcomes. The aim of this study was to determine the impact of MRSA bacteremia on clinical outcomes in patients with a vancomycin MIC near the upper limit of the susceptible range. Patients with MRSA bacteremia were divided into a high-vancomycin-MIC group (2 μg/ml) and a low-vancomycin-MIC group (≤1.0 μg/ml). We examined the relationship between MIC, genotype, primary source of bacteremia, and mortality. Ninety-four patients with MRSA bacteremia, including 31 with a high vancomycin MIC and 63 with a low MIC were analyzed. There was no significant difference between the presence ofagrdysfunction and SCCmectype between the two groups. A higher vancomycin MIC was not found to be associated with mortality. In contrast, high-risk bloodstream infection sources (hazard ratio [HR], 4.63; 95% confidence interval [CI] = 1.24 to 17.33) and bacterial eradication after treatment (HR, 0.06; 95% CI = 0.02 to 0.17), irrespective of vancomycin MIC, were predictors of all-cause 30-day mortality. Our study suggests that a high-risk source of bacteremia is likely to be associated with unfavorable clinical outcomes, but a high vancomycin MIC in a susceptible range, as well as genotype characteristics, are not associated with mortality.

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S209-S210
Author(s):  
Gabriela Andonie ◽  
Elizabeth O Hand ◽  
Kelly R Reveles ◽  
Kristi A Traugott

Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is associated with poor outcomes and increased mortality. Daptomycin (DAP) and ceftaroline (CPT) in combination has been explored as a potential treatment option and showed improved outcomes compared to vancomycin/standard therapy. CPT monotherapy has been evaluated as salvage therapy for MRSA bacteremia but, to our knowledge, not as a comparator to DAP-CPT combination therapy. The purpose of this study is to compare the clinical outcomes of DAP and CPT combination therapy to CPT monotherapy in the setting of MRSA bacteremia. Methods A retrospective chart review of adult patients (≥ 18 years of age) admitted to University Health from January 2017 to December 2020 with a diagnosis of MRSA bacteremia was performed. Patients received either CPT monotherapy or DAP-CPT combination therapy for a minimum of 48 hours during their course of therapy. Results Thirty-two patients met inclusion criteria and were evaluated. Primary source of infection was pulmonary in the CPT monotherapy group (n=7/24; 29.2%) and osteomyelitis in the DAP-CPT combination group (n= 4/8; 50.0%). Median duration of bacteremia was 8 days and 9 days in the CPT monotherapy and DAP-CPT combination group, respectively. Microbiological cure was achieved in 95.8% (n=23/24) of patients in the CPT monotherapy and 100% (n=8/8) of patients in the DAP-CPT combination group. Bacteremia relapse (30 day, p=0.62; 60 day, p=0.63), readmission rates (30 day, p=0.62; 60 day, p=0.63), and mortality rates (30 day, p=0.70; 90 day, p=0.85) were similar in both groups. There was no statistically significant difference in safety parameters, including incidence of acute kidney injury (p=1.00) and creatine kinase elevations (p=1.00). Bone marrow suppression after at least 72 hours of therapy, including anemia, leukopenia, and thrombocytopenia, was also not statistically significant between groups. Conclusion This study was unable to find a statistically significant difference in clinical outcomes between patients receiving CPT monotherapy or DAP-CPT combination therapy. A large prospective, randomized controlled trial to assess CPT monotherapy and DAP-CPT combination therapy for the treatment of persistent MRSA bacteremia is warranted. Disclosures All Authors: No reported disclosures


2013 ◽  
Vol 58 (1) ◽  
pp. 102-109 ◽  
Author(s):  
Thomas J. Dilworth ◽  
Omar Ibrahim ◽  
Pamela Hall ◽  
Jora Sliwinski ◽  
Carla Walraven ◽  
...  

ABSTRACTVancomycin (VAN) is often used to treat methicillin-resistantStaphylococcus aureus(MRSA) bacteremia despite a high incidence of microbiological failure. Recentin vitroanalyses of β-lactams in combination with VAN demonstrated synergistic activity against MRSA. The goal of this study was to examine the impact of combination therapy with VAN and a β-lactam (Combo) on the microbiological eradication of MRSA bacteremia compared to VAN alone. This was a retrospective cohort study of patients with MRSA bacteremia who received Combo therapy or VAN alone. Microbiological eradication of MRSA, defined as a negative blood culture obtained after initiation of therapy, was used to evaluate the efficacy of each regimen. A total of 80 patients were included: 50 patients in the Combo group and 30 patients in the VAN-alone group. Microbiological eradication was achieved in 48 patients (96%) in the Combo group compared to 24 patients (80%) in the VAN-alone group (P= 0.021). In a multivariable model, the Combo treatment had a higher likelihood of achieving microbiological eradication (adjusted odds ratio, 11.24; 95% confidence interval, 1.7 to 144.3;P= 0.01). In patients with infective endocarditis (n= 22), 11/11 (100%) who received Combo therapy achieved microbiological eradication compared to 9/11 (81.8%) treated with VAN alone, but the difference was not statistically significant (P= 0.20). Patients with MRSA bacteremia who received Combo therapy were more likely to experience microbiological eradication of MRSA than patients who received VAN alone.


2019 ◽  
Vol 87 (10) ◽  
Author(s):  
Atul K. Verma ◽  
Christopher Bauer ◽  
Vijaya Kumar Yajjala ◽  
Shruti Bansal ◽  
Keer Sun

ABSTRACT Postinfluenza methicillin-resistant Staphylococcus aureus (MRSA) infection can quickly develop into severe, necrotizing pneumonia, causing over 50% mortality despite antibiotic treatments. In this study, we investigated the efficacy of antibiotic therapies and the impact of S. aureus alpha-toxin in a model of lethal influenza virus and MRSA coinfection. We demonstrate that antibiotics primarily attenuate alpha-toxin-induced acute lethality, even though both alpha-toxin-dependent and -independent mechanisms significantly contribute to animal mortality after coinfection. Furthermore, we found that the protein synthesis-suppressing antibiotic linezolid has an advantageous therapeutic effect on alpha-toxin-induced lung damage, as measured by protein leak and lactate dehydrogenase (LDH) activity. Importantly, using a Panton-Valentine leucocidin (PVL)-negative MRSA isolate from patient sputum, we show that linezolid therapy significantly improves animal survival from postinfluenza MRSA pneumonia compared with vancomycin treatment. Rather than improved viral or bacterial control, this advantageous therapeutic effect is associated with a significantly attenuated proinflammatory cytokine response and acute lung damage in linezolid-treated mice. Together, our findings not only establish a critical role of alpha-toxin in the extreme mortality of secondary MRSA pneumonia after influenza but also provide support for the possibility that linezolid could be a more effective treatment than vancomycin to improve disease outcomes.


2017 ◽  
Vol 61 (4) ◽  
Author(s):  
Nidhu Baby ◽  
Andrew C. Faust ◽  
Terri Smith ◽  
Lyndsay A. Sheperd ◽  
Laura Knoll ◽  
...  

ABSTRACT The objective of this study was to evaluate the impact of pharmacist-ordered methicillin-resistant Staphylococcus aureus (MRSA) PCR testing on the duration of empirical MRSA-targeted antibiotic therapy in patients with suspected pneumonia. This is a retrospective analysis of patients who received vancomycin or linezolid for suspected pneumonia before and after the implementation of a pharmacist-driven protocol for nasal MRSA PCR testing. Patients were included if they were adults of >18 years of age and initiated on vancomycin or linezolid for suspected MRSA pneumonia. The primary endpoint was the duration of vancomycin or linezolid therapy. After screening 368 patients, 57 patients met inclusion criteria (27 pre-PCR and 30 post-PCR). Baseline characteristics were similar between the two groups, with the majority of patients classified as having health care-associated pneumonia (68.4%). The use of the nasal MRSA PCR test reduced the mean duration of MRSA-targeted therapy by 46.6 h (74.0 ± 48.9 h versus 27.4 ± 18.7 h; 95% confidence interval [CI], 27.3 to 65.8 h; P < 0.0001). Fewer patients in the post-PCR group required vancomycin serum levels and dose adjustment (48.1% versus 16.7%; P = 0.02). There were no significant differences between the pre- and post-PCR groups regarding days to clinical improvement (1.78 ± 2.52 versus 2.27 ± 3.34; P = 0.54), length of hospital stay (11.04 ± 9.5 versus 8.2 ± 7.8; P = 0.22), or hospital mortality (14.8% versus 6.7%; P = 0.41). The use of nasal MRSA PCR testing in patients with suspected MRSA pneumonia reduced the duration of empirical MRSA-targeted therapy by approximately 2 days without increasing adverse clinical outcomes.


2015 ◽  
Vol 53 (7) ◽  
pp. 2262-2270 ◽  
Author(s):  
Tyler E. Warkentien ◽  
Faraz Shaikh ◽  
Amy C. Weintrob ◽  
Carlos J. Rodriguez ◽  
Clinton K. Murray ◽  
...  

Combat trauma wounds with invasive fungal infections (IFIs) are often polymicrobial with fungal and bacterial growth, but the impact of the wound microbiology on clinical outcomes is uncertain. Our objectives were to compare the microbiological features between IFI and non-IFI wounds and evaluate whether clinical outcomes differed among IFI wounds based upon mold type. Data from U.S. military personnel injured in Afghanistan with IFI wounds were examined. Controls were matched by the pattern/severity of injury, including blood transfusion requirements. Wound closure timing was compared between IFI and non-IFI control wounds (with/without bacterial infections). IFI wound closure was also assessed according to mold species isolation. Eighty-two IFI wounds and 136 non-IFI wounds (63 with skin and soft tissue infections [SSTIs] and 73 without) were examined. The time to wound closure was longer for the IFI wounds (median, 16 days) than for the non-IFI controls with/without SSTIs (medians, 12 and 9 days, respectively;P< 0.001). The growth of multidrug-resistant Gram-negative rods was reported among 35% and 41% of the IFI and non-IFI wounds with SSTIs, respectively. Among the IFI wounds, times to wound closure were significantly longer for wounds withMucoralesgrowth than for wounds with non-Mucoralesgrowth (median, 17 days versus 13 days;P< 0.01). When wounds withMucoralesandAspergillusspp. growth were compared, there was no significant difference in wound closure timing. Trauma wounds with SSTIs were often polymicrobial, yet the presence of invasive molds (predominant types: orderMucorales,Aspergillusspp., andFusariumspp.) significantly prolonged the time to wound closure. Overall, the times to wound closure were longest for the IFI wounds withMucoralesgrowth.


2019 ◽  
Vol 35 (5) ◽  
pp. 203-207 ◽  
Author(s):  
Mary Joyce B. Wingler ◽  
Darrell T. Childress ◽  
Ricardo A. Maldonado

Background: Optimal treatment of methicillin-resistant Staphylococcus aureus bacteremias (MRSABs) with vancomycin minimum inhibitory concentrations (MICs) high within the susceptible range is of concern due to the high rate of mortality and increased prevalence. Objective: The purpose of this study is to evaluate vancomycin treatment failures in patients with MRSAB stratified by vancomycin MIC. Methods: In this retrospective chart review, patients ≥19 years of age with MRSAB between July 2010 and December 2016 were included if they received intravenous vancomycin for ≥72 hours. Vancomycin treatment failures were compared between patients with vancomycin MICs of ≤1 mg/L and 2 mg/L. Vancomycin treatment failure was defined as microbiological failure at 7 days. Inpatient mortality, 30-day readmission, vancomycin-associated nephrotoxicity, and early bacteremia clearance at 48 to 96 hours were assessed as secondary endpoints. Results: Fifty-eight patients were included in the vancomycin MIC ≤1 mg/L group and 22 patients in the vancomycin MIC 2 mg/L group. No significant difference was found in vancomycin treatment failures at 7 days between groups (88% vs 91%, respectively; P = .850). At 96 hours, there was no significant difference in vancomycin treatment failures between groups (72% vs 90%, respectively; P = .127). No significant difference was found in mortality ( P > .99) or 30-day readmission ( P > .99). Conclusions: In this study, vancomycin treatment failures were not more prevalent in patients with vancomycin MIC of 2 mg/L at 7 days. Regardless of MIC, antibiotics should be switched to an alternative agent at 7 days for persistent bacteremia.


2015 ◽  
Vol 59 (6) ◽  
pp. 3125-3132 ◽  
Author(s):  
Chang Kyung Kang ◽  
Jeong Eun Cho ◽  
Yoon Jeong Choi ◽  
Younghee Jung ◽  
Nak-Hyun Kim ◽  
...  

ABSTRACTStaphylococcal cassette chromosomemecelement (SCCmec) type-dependent clinical outcomes may vary due to geographical variation in the presence of virulence determinants. We compared the microbiological factors and mortality attributed to methicillin-resistantStaphylococcus aureus(MRSA) bacteremia between SCCmectypes II/III and type IV. All episodes of MRSA bacteremia in a tertiary-care hospital (South Korea) over a 4.5-year period were reviewed. We studied the microbiological factors associated with all blood MRSA isolates, includingspatype,agrtype,agrdysfunction, and the genes for Panton-Valentine leukocidin (PVL) and phenol-soluble modulin (PSM)-mec, in addition to SCCmectype. Of 195 cases, 137 involved SCCmectypes II/III, and 58 involved type IV. The mortality attributed to MRSA bacteremia was less frequent among the SCCmectype IV (5/58) than that among types II/III (39/137,P= 0.002). This difference remained significant when adjusted for clinical factors (adjusted odds ratio [aOR], 0.14; 95% confidence interval [CI], 0.04 to 0.49;P= 0.002). Of the microbiological factors tested,agrdysfunction was the only significant factor that showed different positivity between the SCCmectypes, and it was independently associated with MRSA bacteremia-attributed mortality (aOR, 4.71; 95% CI, 1.72 to 12.92;P= 0.003). SCCmectype IV is associated with lower MRSA bacteremia-attributed mortality than are types II/III, which might be explained by the high rate ofagrdysfunction in SCCmectypes II/III in South Korea.


2012 ◽  
Vol 56 (10) ◽  
pp. 5164-5170 ◽  
Author(s):  
Jennifer H. Han ◽  
Kara B. Mascitti ◽  
Paul H. Edelstein ◽  
Warren B. Bilker ◽  
Ebbing Lautenbach

ABSTRACTReduced vancomycin susceptibility (RVS) may lead to poor clinical outcomes inStaphylococcus aureusbacteremia. The objective of this study was to evaluate the clinical and economic impact of RVS in patients with bacteremia due toS. aureus. A cohort study of patients who were hospitalized from December 2007 to May 2009 withS. aureusbacteremia was conducted within a university health system. Multivariable logistic regression and zero-truncated negative binomial regression models were developed to evaluate the association of RVS with 30-day in-hospital mortality, length of stay, and hospital charges. One hundred thirty-four (34.2%) of a total of 392 patients had bacteremia due toS. aureuswith RVS as defined by a vancomycin Etest MIC of >1.0 μg/ml. Adjusted risk factors for 30-day in-hospital mortality included the all patient refined-diagnosis related group (APRDRG) risk-of-mortality score (odds ratio [OR], 7.11; 95% confidence interval [CI], 3.04 to 16.6), neutropenia (OR, 13.4; 95% CI, 2.46 to 73.1), white blood cell count (OR, 1.05; 95% CI, 1.01 to 1.09), immunosuppression (OR, 6.31; 95% CI, 1.74 to 22.9), and intensive care unit location (OR, 3.51; 95% CI, 1.65 to 7.49). In multivariable analyses, RVS was significantly associated with increased mortality in patients withS. aureusbacteremia as a result of methicillin-susceptible (OR, 3.90; 95% CI, 1.07 to 14.2) but not methicillin-resistant (OR, 0.53; 95% CI, 0.19 to 1.46) isolates. RVS was associated with greater 30-day in-hospital mortality in patients with bacteremia due to methicillin-susceptibleS. aureusbut not methicillin-resistantS. aureus. Further research is needed to identify optimal treatment strategies to reduce mortality associated with RVS inS. aureusbacteremia.


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