Management of Catheter-Related<Emphasis Type="Italic"> Staphylococcus aureus</Emphasis> Bacteremia: When May Sonographic Study Be Unnecessary?

This study reviews the outcome of patients with uncomplicated catheter-related Staphylococcus aureus bacteremia diagnosed in our hospital from January 1997 to December 1999 and treated with short-course antibiotic therapy. Our aim was to assess the effectiveness of this regimen for minimizing complications (relapses, endocarditis and metastatic foci). A total of 213 episodes of bacteremia were registered and 167 (78.4%) were nosocomial. Among these, 87 (52.1%) were catheter-related Staphylococcus aureus bacteremia and 20 were primary nosocomial bacteremia. Endocarditis was diagnosed during the acute episode in 7/107 of these patients (2 by persistent fever after catheter removal and 5 by metastatic foci; 3 of them also had cardiac risk factors) and confirmed with transesophageal echocardiography. Among the 84/87 catheter-related Staphylococcus aureus bacteremia and 16/20 primary nosocomial bacteremia patients who did not develop endocarditis, 31 patients died during the acute episode (16 due to sepsis despite initiation of antibiotic treatment and 15 due to the underlying disease) and five had osteoarticular foci. The remaining 64 episodes were considered to be uncomplicated bacteremia (no cardiac risk factors, persistent fever, metastatic foci, or clinical signs of endocarditis) and were treated with 10–14 days of high-dose antistaphylococcal antibiotics. Echocardiography was not mandatory in these patients. Of the 64 uncomplicated episodes, 62 were followed for at least 3 months and none relapsed or developed endocarditis. Even though some of the patients might have had subclinical endocarditis, short-course therapy with high doses of antistaphylococcal antibiotics was effective for treating uncomplicated catheter-related Staphylococcus aureus bacteremia. Transesophageal echocardiography may not be necessary in these cases.     

Staphylococcus aureus nasal carriage as a marker for subsequent staphylococcal infections in intensive care unit patients

From January to December 1994, 752 consecutive patients admitted to intensive care units (ICU) for more than two days were studied prospectively forStaphylococcus aureus colonization and infection. Nasal swabs were obtained at admission and weekly during the ICU stay. At ICU admission 166 patients (22.1%) wereStaphylococcus aureus nasal carriers, while 586 were free of nasal colonization. Of the 166 nasal carriers, 163 harbored methicillin-sensitiveStaphylococcus aureus (MSSA) and three methicillinresistantStaphylococcus aureus (MRSA). During the ICU stay 24 of the 586 noncolonized patients became nasal carriers (11 MSSA and 13 MRSA), and one nasal carrier initially colonized by MSSA was recolonized by MRSA. Staphylococcal infections were documented in 51 (6.8%) of the total 752 patients. After 14 days of ICU stay, the probability of developing staphylococcal infections was significantly higher for those patients who were nasal carriers at ICU admission than for those found to be initially negative (relative risk 59.6, 95% Cl 20.37–184.32; p<0.0001). In patients with ICU-acquired nasal colonization, most infections were documented prior to or at the time of the detection of the nasal colonization; thus, in this group of patients nasal carriage showed a lower predictive value for subsequentStaphylococcus aureus infections than that described classically. Paired isolates of nasal colonizing and clinical strains were studied by pulsed-field gel electrophoresis (PFGE) andmecA polymorphism analysis in 30 patients; identity was demonstrated in all but two patients. The results suggest that, outside the setting of an outbreak of MRSA, the detection ofStaphylococcus aureus nasal carriers on admission may be particularly useful in identifying those patients who are at high risk for developing staphylococcal infections during their ICU stay.     

Long-Term Infectious Complications and Their Relation to Treatment Duration in Catheter-Related Staphylococcus aureus Bacteremia

 The optimal duration of treatment for catheter-related Staphylococcus aureus bacteremia is not known. Short courses (≤2 weeks) of therapy should be viewed with caution because essential data on late complications, such as osteomyelitis and metastatic abscesses, are lacking. This study represents a retrospective analysis of the data from 49 adult patients hospitalised in the period 1994–1996 (mean age, 57 years; range, 20–90 years; 47% male) and from whom Staphylococcus aureus was cultured concomitantly from peripheral blood and catheter segments. Forty-six venous catheters, two arterial catheters, and one unknown type of catheter were used. Forty-four patients were treated with effective anti-Staphylococcus aureus antibiotics. Twenty patients had a favourable outcome, defined as no complication and no death during 1 year of follow-up, 24 patients had complications, 14 patients died due to attributable mortality, and 5 other patients died of an underlying disease without showing signs or symptoms of a complication. Patients were categorised according to the duration of treatment. There were small differences between a shorter (1–14 days) and a longer ( 1 14 days) course of antibiotics with regard to favourable outcome (41% vs. 33%), complications (48% vs. 53%), attributable death (31% vs. 20%), and death due to underlying disease (41% vs. 33%), respectively. The rates of complications and death were high, but a definite conclusion cannot be drawn because the study was underpowered. More randomised trials are needed, but, until the results of such trials are available, the duration of therapy should not be shortened to less than 14 days.     

Significance of the isolation of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> from a central venous catheter tip in the absence of concomitant bacteremia: a clinical approach

The optimal approach following the isolation of Staphylococcus aureus from an intravascular catheter tip in the absence of concomitant bacteremia remains unclear. We aimed to determine the rate of delayed complications in these patients. We performed a retrospective observational study (during the period 2002–2012) including patients with a catheter tip culture yielding S. aureus. Patients were followed up for ≥6 months. The primary endpoint was the occurrence of delayed staphylococcal complications (either bacteremia and/or metastatic distant infections). A total of 113 patients were included (75 % male, median age 61 years): 46 and 67 with negative and positive blood cultures, respectively. We found a lower rate of delayed staphylococcal complications in cases with no bacteremia within 48 h since catheter removal than in cases of confirmed S. aureus catheter-related bacteremia (0.0 % vs. 25.4 %; p-value?<?0.001). In the group without bacteremia, there was a subgroup of 15 patients (32.6 %) who did not receive antimicrobial treatment. Again, delayed complications occurred less commonly in this subgroup of patients without bacteremia (0.0 % vs. 25.4 %; p-value?=?0.033). In contrast to patients with S. aureus catheter-related bacteremia, no delayed infectious complications were observed in patients with an isolated catheter tip culture yielding S. aureus and negative blood cultures within 48 h of catheter removal. Futures studies are needed to assess if the therapeutic approach could be different for this group of patients.     

Predisposing Factors and Outcome of Staphylococcus aureus Bacteremia in Neutropenic Patients with Cancer

 Staphylococcus aureus caused 30 of 438 (7%) cases of bacteremia in neutropenic patients with cancer during a 10-year study period. Acute leukemia as an underlying disease and severe oral mucositis were more frequent among patients with Staphylococcus aureus bacteremia (57% vs. 33%, P=0.01, and 32% vs. 12%, P=0.006, respectively) than among the 151 patients who had gram-negative bacteremia during the same study period. The most frequent source of Staphylococcus aureus bacteremia was the venous catheter (35% vs. 1%; P=0.00001). Septic metastases were more frequent in patients with Staphylococcus aureus bacteremia (14% vs. 4%, P=0.03). Attributable mortality was 10% and overall mortality 23%. Staphylococcus aureus bacteremia remains a significant cause of morbidity and mortality in neutropenic patients with cancer.     

Impact of a computerized alert system for bacteremia notification on the appropriate antibiotic treatment of Staphylococcus aureus bloodstream infections

A computerized alert system (CAS) has been introduced to notify bacteremia in real time. We evaluated the impact of the CAS on the administration of appropriate antibiotics in patients with Staphylococcus aureus bloodstream infections (BSIs). We retrospectively reviewed the medical records of patients with S. aureus BSI for each 1-year control and intervention periods, before and after the implementation of the CAS. The proportions of appropriate antibiotic treatment were compared between the control and intervention periods. The 30-day mortality of S. aureus bacteremia was also assessed in the study population. A total of 313 patients were included in the study. Appropriate antibiotics were initiated 7 h earlier in the intervention period (mean time, 13.5 h vs. 20.0 h; p?=?0.136). The administration of appropriate antibiotics within the 24 h after blood acquisition was similar between the two periods, but this significantly increased from 3.3 % in the control period to 10.6 % in the intervention during the 24–36 h interval (p?=?0.012). In the subgroup analysis, similar trends were observed in patients with methicillin-resistant isolates (6.7 % vs. 18.2 %; p?=?0.032) and hospital-onset infection (3.5 % vs. 17.1 %; p?=?0.004). The independent risk factors for 30-day mortality of S. aureus bacteremia were age, a high Pitt bacteremia score, an increased Charlson’s weighted index of comorbidity, and hospital-onset infection, although the appropriateness of antibiotic therapy within 36 h and the CAS were not identified as predictors. The CAS increased the proportion of appropriate antimicrobial therapy during the 24–36 h interval after bacteremia onset in patients with S. aureus BSIs.     

Impact of initial antibiotic choice and delayed appropriate treatment on the outcome of Staphylococcus aureus bacteremia

The study presented here investigated the impact of initial antibiotic choice (β-lactams vs vancomycin) on the outcome of 342 patients with Staphylococcus aureus bacteremia (50.9% with methicillin-resistant isolates) encountered between 1 January 2002 and 30 June 2003. Initial antibiotics were inappropriate (β-lactams) in 60 (34.5%) methicillin-resistant cases and suboptimal (vancomycin) in 62 (36.9%) methicillin-susceptible cases. Time to effective antibiotic therapy was longer in methicillin-resistant cases (25.5±28.6 vs 9.6±16.6 h; p<0.0005). All-cause in-hospital mortality was higher with inappropriate therapy (35.0 vs 20.9%; p=0.02). Initial vancomycin treatment was associated with a higher incidence of delayed clearance (≥3 days) of methicillin-susceptible bacteremia (56.3 vs 37.0%; p=0.03). The results indicate inappropriate initial therapy is associated with higher in-hospital mortality and initial vancomycin may delay clearance.     

Risk factors for nosocomial bacteremia due to methicillin-resistantStaphylococcus aureus

In a prospective surveillance study (February 1990–December 1991) performed at a 1000-bed teaching hospital to identify risk factors for nosocomial methicillin-resistantStaphylococcus aureus (MRSA) bacteremia, 309 patients were found to be colonized (n=103; 33 %) or infected (n=206; 67 %) by MRSA. Sixty-three of them developed bacteremia. Compared with 114 patients who had nosocomial bacteremia caused by methicillin-sensitiveStaphylococcus aureus during the same period of time, MRSA bacteremic patients had more severe underlying diseases (p<0.01), were more often in intensive care units (p<0.01) and had received prior antibiotic therapy more frequently (p<0.01). To further identify risk factors for MRSA bacteremia, univariate and multivariate analyses of this series of 309 patients were performed using the occurrence of MRSA bacteremia as the dependent variable. Among 14 variables analyzed, intravascular catheterization, defined as one or more intravascular catheters in place for more than 48 h, was the only variable selected by a logistic regression model as an independent risk factor (OR=2.7, CI=1.1–6.6). The results of this study reinforce the concept that recent antibiotic therapy may predispose patients to MRSA infection and suggest that among patients colonized or infected by MRSA, those with intravascular catheters are at high risk of developing MRSA bacteremia.     

Differences between methicillin-resistant Staphylococcus aureus bacteremic isolates harboring type IV and type V staphylococcal cassette chromosome mec genes based on prior patient healthcare exposure

This observational study enrolled adult patients with bacteremia due to methicillin-resistant Staphylococcus aureus (MRSA) who were treated at the emergency department of a teaching hospital from 2001 to 2007. MRSA isolates with type IV and type V staphylococcal cassette chromosome mec (SCCmec) genes (SCC IV/V-MRSA) were included in the final analysis. Healthcare-associated SCC IV/V-MRSA (HA-SCC IV/V-MRSA) and community-acquired SCC IV/V-MRSA (CA-SCC IV/V-MRSA) were defined as the identification of an SCC IV/V-MRSA isolate from a patient with and without healthcare-associated risk factors, respectively. Thirty-four cases of CA-SCC IV/V-MRSA (20 SCCmec type IV, 14 SCCmec type V) and 81 cases of HA-SCC IV/V-MRSA (59 SCCmec type IV, 22 SCCmec type V) bacteremia were identified. Vascular device-associated infections were a significant infection source in HA-SCC IV/V-MRSA bacteremia cases. SCCmec type IV HA-SCC IV/V-MRSA isolates (3.4%) were significantly less likely to carry the Panton–Valentine leukocidin (PVL) gene than SCCmec type IV CA-SCC IV/V-MRSA isolates (35.0%, p = 0.001). The 90-day cumulative probability of survival was 76% for patients with CA-SCC IV/V-MRSA bacteremia and 66% for patients with HA-SCC IV/V-MRSA bacteremia (p = 0.247, by the Wilcoxon rank-sum test). Significant differences in antimicrobial susceptibility were observed between bacterial isolates from patients with CA-SCC IV/V-MRSA bacteremia and HA-SCC IV/V-MRSA bacteremia.     

Necrotizing fasciitis caused byStaphylococcus aureus

Two patients with rapidly progressive necrotizing fasciitis of a lower extremity due toStaphylococcus aureus as a single pathogen are described. In both patients the portal of entry was attributed to needle puncture (intra-articular injection and intravenous catheter, respectively), followed by bacteremia. Necrotizing fasciitis occurred in a site remote from the needle puncture, suggesting metastatic infection. One patient developed toxic shock syndrome and the other a sunburn-like rash and erythematous mucosae with strawberry tongue. One patient died, and the other required above-knee amputation due to secondary infectious complications.Staphylococcus aureus may mimic the presentation of invasive group A streptococcal infections. A history of needle puncture should alert the physician to the possibility ofStaphylococcus aureus infection.     

Clinical Study of 44 Cases of Staphylococcus aureus Meningitis

In order to describe the clinical features and outcome of Staphylococcus aureus meningitis, the charts of 44 cases seen at one teaching hospital during a 20-year period were retrospectively reviewed. Staphylococcus aureus was the fifth most common cause of bacterial meningitis (10.2% of cases). There were 28 (63%) cases of postoperative meningitis and 16 (37%) of spontaneous meningitis. Patients with postoperative meningitis were younger than patients with spontaneous meningitis (mean age, 40.3 vs. 59.3 years; P=0.04) and had a lower frequency of community-acquired infection (32.1% vs. 93.8%; P<0.01), severe underlying diseases (28% vs. 87%; P<0.01) and associated staphylococcal infection (35% vs. 75%; P=0.01). The clinical presentation was similar in both groups, but patients with postoperative meningitis had a lower frequency of altered mental status (39% vs. 75%; P=0.02), meningeal signs (28% vs. 62%; P=0.02), petechial rash (0% vs. 18%; P=0.04), bacteremia (7% vs. 75%; P<0.01), and septic shock (0% vs. 44%; P<0.01). Most patients were treated with cloxacillin or vancomycin, with or without rifampicin, for a mean period of 22.5 days (range, 1–100 days). Overall mortality was 27%, and the mortality rate was higher for cases of spontaneous than postoperative meningitis (50% vs. 14%; P=0.01). Mortality correlated significantly with advanced age, spontaneous meningitis, altered mental status, and the presence of severe underlying diseases, bacteremia, and septic shock. Electronic Publication     

Time to positivity of follow-up blood cultures in patients with persistent Staphylococcus aureus bacteremia

We investigated the clinical usefulness of time to blood culture positivity (TTP) of follow-up positive blood cultures (FUPBC) in patients with persistent Staphylococcus aureus bacteremia (SAB). Of the patients who did not have resolution of SAB after primary therapeutic intervention (PTI), patients who had decreases in TTP of FUPBC after PTI more frequently experienced 30-day mortality or secondary foci of infection than those who did not have decrease in TTP (83.3% vs. 28.6%; p?=?0.005).     

Risk factors for bacteremia in patients with limb cellulitis

The aim of this study was to identify the risk factors for bacteremia in patients with limb cellulitis. Using the administrative and microbiology laboratory databases of a community teaching hospital, a review was conducted of all cases of community-acquired limb cellulitis that occurred during the period 1997–2004 and in which blood cultures had been performed. A comparison of demographical, clinical, and analytical data of patients with bacteremia versus patients without bacteremia was performed by univariate and multivariate analyses. Of 2,678 patients with cellulitis who presented to the hospital’s emergency department, 308 were diagnosed with limb cellulitis and had blood cultures. Of these, 57 (18.5%) had bacteremia. In 24 of the 57 (42.1%) patients with bacteremia, the microorganism isolated in blood cultures was non-group-A β-hemolytic Streptococcus, and in another 14 (24.6%), the microorganism identified was a gram-negative bacterium. Staphylococcus aureus was determined as the cause of bacteremia in just 6 (10.5%) patients and group A Streptococcus in 2 (3.5%). By logistic regression analysis, the following factors were associated with bacteremia: absence of previous antibiotic treatment (OR 5.3, 95% CI 1.4–20.3), presence of two or more comorbid factors simultaneously (OR 4.3, 95% CI 1.6–11.7), length of illness <2 days OR 2.44, 95% CI 1.07–5.56), and proximal limb involvement (OR 6, 95% CI 3.03–12.04). Patients with limb cellulitis who exhibit any of these characteristics are at increased risk of bacteremia. In such patients, it is imperative that blood cultures be performed.     

Association betweenStaphylococcus aureus nasopharyngeal colonization and septicemia in patients infected with the human immunodeficiency virus

In an attempt to identify risk factors forStaphylococcus aureus septicemia, 136 consecutive HIV-infected patients were investigated for the presence of nasopharyngeal colonization withStaphylococcus aureus and subsequentStaphylococcus aureus infection. Sixty of 136 (44.1 %) HIV-infected patients had staphylococci which were detected in the nasopharynx on initial culture compared to 12 of 39 (30.8 %) patients with chronic diseases and 11 of 47 (23.4 %) healthy hospital staff. Another 12 HIV-infected subjects proved to beStaphylococcus aureus carriers on follow-up cultures. Patients with full-blown AIDS had a higher carriage rate compared to subjects who were only HIV-positive (p<0.05), indicating thatStaphylococcus aureus colonized patients were more severely ill. Eight patients withStaphylococcus aureus septicemia were observed, all of whom were carriers; no septicemia occurred in the non-colonized patients (p<0.01). Colonized patients with neutropenia (< 1000/µl) were significantly more likely to develop septicemia (p<0.01). Nasopharyngeal colonization withStaphylococcus aureus and the presence of an indwelling catheter were established to be factors that help identify patients at risk of acquiring subsequentStaphylococcus aureus infection.     

Outcome of antibiotic lock technique for persistent central venous catheter-associated coagulase-negative Staphylococcus bacteremia in children

The purpose of this study was to assess the long-term effectiveness of the antibiotic lock technique (ALT) in conjunction with systemic antibiotics for the salvage of long-term central venous catheter (CVC)-associated coagulase-negative Staphylococcus (CONS) bloodstream infections (BSIs) in children. A retrospective study of children with CVC-associated CONS BSIs treated with systemic vancomycin and ALT with vancomycin was carried out. The primary outcome was the immediate and 3-month success rate of salvage of the CVC. During the study period, 23 patients had persistent CONS bacteremia and were treated with ALT and systemic vancomycin. Of the 23 vancomycin lock treatments, eight catheters were removed during the acute event because of persistent bacteremia, six had relapse of CONS bacteremia within 30 days, and two had relapse within 90 days. Only seven CVCs (30%) were salvaged. Long-term transcutaneous CVCs (Hickman CVCs) were significantly associated with higher salvage rates than implantable ports (75% vs. 18%, P = 0.05). ALT with vancomycin for CVC-associated bacteremia has a limited long-term effectiveness, especially with implantable ports. Larger prospective studies are needed for the long-term evaluation of this technique.     

Pan-European early switch/early discharge opportunities exist for hospitalized patients with methicillin-resistant Staphylococcus aureus complicated skin and soft tissue infections

The objective of this study was to document pan-European real-world treatment patterns and healthcare resource use and estimate opportunities for early switch (ES) from intravenous (IV) to oral antibiotics and early discharge (ED) in hospitalized patients with methicillin-resistant Staphylococcus aureus (MRSA) complicated skin and soft tissue infections (cSSTIs). This retrospective observational medical chart review study enrolled 342 physicians across 12 European countries who collected data from 1542 patients with documented MRSA cSSTI who were hospitalized (July 2010 to June 2011) and discharged alive (by July 2011). Data included clinical characteristics and outcomes, hospital length of stay (LOS), MRSA-targeted IV and oral antibiotic use, and ES and ED eligibility according to literature-based and expert-validated criteria. The most frequent initial MRSA-active antibiotics were vancomycin (50.2%), linezolid (15.1%), clindamycin (10.8%), and teicoplanin (10.4%). Patients discharged with MRSA-active antibiotics (n = 480) were most frequently prescribed linezolid (42.1%) and clindamycin (19.8%). IV treatment duration (9.3 ± 6.5 vs. 14.6 ± 9.9 days; p <0.001) and hospital LOS (19.1 ± 12.9 vs. 21.0 ± 18.2 days; p 0.162) tended to be shorter for patients switched from IV to oral treatment than for patients who received IV treatment only. Of the patients, 33.6% met ES criteria and could have discontinued IV treatment 6.0 ± 5.5 days earlier, and 37.9% met ED criteria and could have been discharged 6.2 ± 8.2 days earlier. More than one-third of European patients hospitalized for MRSA cSSTI could be eligible for ES and ED, resulting in substantial reductions in IV days and bed-days, with potential savings of €2000 per ED-eligible patient.     

Trends and outcome of nosocomial and community-acquired bloodstream infections due to Staphylococcus aureus in Finland, 1995–2001

In Finland, Staphylococcus aureus bloodstream infections are caused predominantly (>99%) by methicillin-sensitive strains. In this study, laboratory-based surveillance data on Staphylococcus aureus bloodstream infections occurring in Finland from 1995 to 2001 were analyzed. Preceding hospitalizations for all persons with Staphylococcus aureus bloodstream infections were obtained from the national hospital discharge registry, and data on outcome was obtained from the national population registry. An infection was defined as nosocomial when a positive blood culture was obtained more than 2 days after hospital admission or within 2 days of admission if there was a preceding hospital discharge within 7 days. A total of 5,045 cases were identified. The annual incidence of Staphylococcus aureus bloodstream infection rose by 55%, from 11 per 100,000 population in 1995 to 17 in 2001. The increase was detected in all adult age groups, though it was most distinct in patients >74 years of age. Nosocomial infections accounted for 51% of cases, a proportion that remained unchanged. The 28-day death-to-case ratio ranged from 1% in the age group 1–14 years to 33% in patients >74 years of age. The 28-day death-to-case ratios for nosocomial and community-acquired infections were 22% and 13%, respectively, and did not change over time. The increase in incidence among elderly persons resulted in an increase in the annual rate of mortality associated with Staphylococcus aureus bloodstream infections, from 2.6 to 4.2 deaths per 100,000 population per year. Staphylococcus aureus bloodstream infections are increasing in Finland, a country with a very low prevalence of methicillin resistance. While the increase may be due in part to increased reporting, it also reflects a growing population at risk, affected by such factors as high age and/or severe comorbidity.     

Accuracy of blood culture for early diagnosis of mediastinitis in febrile patients after cardiac surgery

Postsurgical mediastinitis (PSM) remains a major cause of morbidity and mortality in patients undergoing cardiac surgery procedures. Although prompt diagnosis is crucial in these patients, neither clinical data nor imaging techniques have shown enough sensitivity or specificity for early diagnosis of PSM. The aim of the present study was to assess the validity of blood cultures as a diagnostic test for the early detection of PSM in patients who become febrile after cardiac surgery procedures. During a 4-year period (1999–2002), patients who developed fever (>37.8°C) in the first 60 days after a cardiac surgery procedure were evaluated. Blood cultures were drawn from these patients. PSM was defined as deep infection involving retrosternal tissue and/or the sternal bone directly observed by the surgeon and confirmed microbiologically. Three criteria for positivity of blood cultures were applied: bacteremia, staphylococcal bacteremia, or Staphylococcus aureus bacteremia. For purposes of the analysis, a positive blood culture in patients with PSM was considered a true-positive test and a negative blood culture a false-negative test. Otherwise, in febrile patients without PSM in the postsurgery period, a positive blood culture was considered a false-positive test and a negative blood culture a true-negative test. Blood cultures were drawn from 266 febrile patients in the postsurgery period. PSM occurred in 38 patients (26 cases due to S. aureus, 8 to Staphylococcus epidermidis, 3 to gram-negative enteric bacteria, and one to Pseudomonas aeruginosa). Within the 60-day postsurgical period, blood culture as a diagnostic test was most accurate in patients with S. aureus bacteremia, providing 68% sensitivity, 98% specificity, a positive predictive value of 87%, and a negative predictive value of 95%. If the analysis was limited to the period during which patients are at maximum risk for PSM (day 7–20), the values in patients with S. aureus bacteremia were as follows: 73% sensitivity, 98% specificity, 90% positive predictive value, and 93% negative predictive value. Blood culture is an accurate test for the early diagnosis of PSM in febrile patients after cardiac surgery, particularly in institutions where S. aureus is prevalent in this context. A negative blood culture practically excludes PSM and, during the period of maximum risk for PSM, the presence of S. aureus bacteremia should compel early surgical management.Presented in part at the 43rd Interscience Conference of Antimicrobial Agents and Chemotherapy in Chicago, September 14–17, 2003, slide session K-1300.     

Daptomycin versus vancomycin for osteoarticular infections due to methicillin-resistant Staphylococcus aureus (MRSA): a nested case–control study

Vancomycin is the standard antibiotic for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. While daptomycin is approved for MRSA bacteremia, its effectiveness in osteoarticular infections (OAIs) has not been established. A 1:2 nested case–control study of adult patients with MRSA OAIs admitted to an academic center from 2005 to 2010 was carried out. Clinical outcomes and drug toxicity in patients treated with daptomycin versus vancomycin were compared. Twenty patients with MRSA OAIs treated with daptomycin were matched to 40 patients treated with vancomycin. The median age of the patients was 52 years (range, 25–90), and 40 (67 %) were male. Most patients had osteomyelitis (82 %), predominantly from a contiguous source (87 %). Forty percent were diabetics. Diabetic patients were more likely to receive vancomycin than daptomycin [20 (50 %) vs. 4 (20 %); p?=?0.03]. Vancomycin was more often combined with antibiotics other than daptomycin [22 (55 %) vs. 5 (25 %); p?=?0.03]. The median total antibiotic treatment duration was 48 (daptomycin) vs. 46 days (vancomycin) (p?=?0.5). Ninety percent of daptomycin-treated patients had previously received vancomycin for a median of 14.5 days (range, 2–36). Clinical success rates were similar between daptomycin and vancomycin at 3 months [15 (75 %) vs. 27 (68 %); p?=?0.8] and 6 months [14 (70 %) vs. 23 (58 %); p?=?0.5], even after propensity score-based adjustment for antibiotic assignment. The frequency of adverse events was similar between treatment groups [1 (5 %) vs. 7 (18 %); p?=?0.2]. Daptomycin and vancomycin achieved similar rates of clinical success and drug tolerability. Daptomycin is a reasonable alternative for treating MRSA OAIs, particularly in patients where therapy with vancomycin has not been well tolerated.     

C-reactive protein predicts persistent bacteremia caused by community-acquired methicillin-resistant Staphylococcus aureus strain

There is limited data on persistent bacteremia (PB) caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Here, we aimed to investigate the clinical and microbiological characteristics of PB caused by the major CA-MRSA strain in Korea (ST72-SCCmecIV). All adult patients with S. aureus bacteremia were prospectively investigated from August 2008 to December 2018. Patients with ST72 MRSA bacteremia were included in the study. Patients were stratified into the PB group (defined as positive blood cultures for?≥?3 days) and short bacteremia (SB) group. A total of 291 patients were included, comprising 115 (39.5%) with PB and 176 (60.5%) with SB. Although the 30-day mortality did not differ between PB and SB, recurrent bacteremia within 12 weeks was significantly more common in PB (8.7% vs 1.7%; P?=?0.01). Multivariate analysis showed risk factors of PB were liver cirrhosis (adjusted odds ratio [aOR], 3.27; 95% confidence interval [CI], 1.50–7.12), infective endocarditis (aOR, 7.13; 95% CI, 1.37–37.12), bone and joint infections (aOR, 3.76; 95% CI, 1.62–8.77), C-reactive protein?≥?10 mg/dL (aOR, 2.20; 95% CI, 1.22–3.95), metastatic infection (aOR, 7.35; 95% CI, 3.53–15.29), and agr dysfunction (aOR, 2.47; 95% CI, 1.05–5.81). PB occurred in approximately 40% of bacteremia caused by ST72 MRSA with a significantly higher recurrence rate. Patients with risk factors of PB, including liver cirrhosis, high initial CRP, infective endocarditis, or bone and joint infections, might require early aggressive treatment.