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Summary Background Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a global threat. We therefore analysed the bacterial characteristics of CRKP infections and the clinical outcomes of patients with CRKP infections across different countries. Methods In this prospective, multicentre, cohort study (CRACKLE-2), hospitalised patients with cultures positive for CRKP were recruited from 71 hospitals in Argentina, Australia, Chile, China, Colombia, Lebanon, Singapore, and the USA. The first culture positive for CRKP was included for each unique patient. Clinical data on post-hospitalisation death and readmission were collected from health records, and whole genome sequencing was done on all isolates. The primary outcome was a desirability of outcome ranking at 30 days after the index culture, and, along with bacterial characteristics and 30-day all-cause mortality (a key secondary outcome), was compared between patients from China, South America, and the USA. The desirability of outcome ranking was adjusted for location before admission, Charlson comorbidity index, age at culture, Pitt bacteremia score, and anatomical culture source through inverse probability weighting; mortality was adjusted for the same confounders, plus region where relevant, through multivariable logistic regression. This study is registered at ClinicalTrials.gov , NCT03646227 , and is complete. Findings Between June 13, 2017, and Nov 30, 2018, 991 patients were enrolled, of whom 502 (51%) met the criteria for CRKP infection and 489 (49%) had positive cultures that were considered colonisation. We observed little intra-country genetic variation in CRKP. Infected patients from the USA were more acutely ill than were patients from China or South America (median Pitt bacteremia score 3 [IQR 2–6] vs 2 [0–4] vs 2 [0–4]) and had more comorbidities (median Charlson comorbidity index 3 [IQR 2–5] vs 1 [0–3] vs 1 [0–2]). Adjusted desirability of outcome ranking outcomes were similar in infected patients from China (n=246), South America (n=109), and the USA (n=130); the estimates were 53% (95% CI 42–65) for China versus South America, 50% (41–61) for the USA versus China, and 53% (41–66) for the USA versus South America. In patients with CRKP infections, unadjusted 30-day mortality was lower in China (12%, 95% CI 8–16; 29 of 246) than in the USA (23%, 16–30; 30 of 130) and South America (28%, 20–37; 31 of 109). Adjusted 30-day all-cause mortality was higher in South America than in China (adjusted odds ratio [aOR] 4·82, 95% CI 2·22–10·50) and the USA (aOR 3·34, 1·50–7·47), with the mortality difference between the USA and China no longer being significant (aOR 1·44, 0·70–2·96). Interpretation Global CRKP epidemics have important regional differences in patients’ baseline characteristics and clinical outcomes, and in bacterial characteristics. Research findings from one region might not be generalisable to other regions. Funding The National Institutes of Health.

A 31-year-old man was admitted to our hospital with a recent history of generalized seizures. Three months earlier, he started with intermittent hemoptysis. CT scan showed a cavitary lung lesion in the upper segment of the right inferior lobe (RIL). Because of his job as a social worker in a high-risk population, he started treatment for Mycobacterium TB; however, the BAL culture result was negative. At the time of his current admission, he has continued taking rifampicin, isoniazid, pyrazinamide, and levofloxacin. He denied the use of any illicit drugs or alcohol. He had no history of smoking. One year earlier, he visited Southeast Asia, Oceania, and South Africa for several months. He reported a weight loss of 7 kg since then. Except for a recurrent oral candidiasis, he did not have a relevant medical history. His family history was notable for mother with lupus, and brother with sarcoidosis.

Central nervous system (CNS) toxoplasmosis is a well-known opportunistic infection in patients with AIDS. Spinal cord involvement and brain hemorrhage are very infrequent manifestations of CNS toxoplasmosis. In this report, we describe a patient with unknown AIDS presenting with bilateral headaches and new onset of bilateral leg weakness, diagnosed with CNS toxoplasmosis with a CSF polymerase chain reaction (PCR) for T. gondii, associated with spinal cord involvement (a central lesion in the conus medullaris) and multiple brain lesions with hemorrhage. The patient required therapy with pyrimethamine, sulfadiazine, and dexamethasone, with favorable outcomes after 30 days of therapy. Our case re-emphasizes the diagnosis of CNS toxoplasmosis in patients with advance HIV disease and spinal cord involvement. A high index of suspicion is needed, especially in HIV/AIDS patients not receiving HAART, who are seropositive for T. gondii, have a CD4+ count less than 100 cells/mm3, and present with symptoms consistent with spinal disease and even more with suggestive coincident brain lesions.

An epidemic of dengue virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) co-infections occurred in Argentina during 2020. We describe the clinical characteristics and outcomes in a cohort of patients hospitalized because of co-infection. We retrospectively identified 13 patients from different hospitals in Buenos Aires who had confirmed infection with SARS-CoV-2 and dengue virus and obtained clinical and laboratory data from clinical records. All patients had febrile disease when hospitalized. Headache was a common symptom. A total of 8 patients had respiratory symptoms, 5 had pneumonia, and 3 had rash. Nearly all patients had lymphopenia when hospitalized. No patients were admitted to an intensive care unit or died during follow up. Co-infection with SARS-CoV-2 and dengue virus can occur in patients living in areas in which both viruses are epidemic. The outcome of these patients did not seem to be worse than those having either SARS-CoV-2 or dengue infection alone.

Acute bacterial skin and skin structure infections (ABSSSI) are among the most frequent infectious diseases. Recently, several new antibiotics with activity against MRSA have been approved. Tedizolid, a second-generation oxazolidinone approved for ABSSSI offers theoretical advantages over first-generation oxazolidinones.A comprehensive online search of Medline, ClinicalTrials.gov, and conference presentations was made, selecting articles between January 2000 and April 2020. In this review, the authors discuss the chemical and microbiological properties of tedizolid, summarize its efficacy, safety, and potential role in the treatment of ABSSSI as well as the potential for future indications.Tedizolid has proven to be non-inferior compared to linezolid for the treatment of ABSSSI in two registrational phase III clinical trials, being well tolerated. Tedizolid exhibits antibacterial activity against the most important ABSSSI pathogens (including multidrug-resistant strains of MRSA), as well as mycobacteria and Nocardia. It appears to have a safe profile, including decreased myelotoxicity and no significant drug interactions. Preliminary studies with longer duration of therapy seem to confirm these potential benefits. Overall, tedizolid expands the newly acquired armamentarium to treat ABSSSI. The role of tedizolid for other indications is under investigation and has yet to be determined.

Health care workers (HCWs) are at high risk for SARS-CoV-2. In addition, pre-symptomatic or asymptomatic transmission accounts for around half of the cases. Saliva testing is an option to detect SARS-CoV-2 infection. To determine the performance of saliva samples for screening, HCWs were tested for SARS-CoV-2 by RT-PCR. Those with a positive result in saliva were tested by nasopharyngeal swabbing for viral RNA detection and blood collection to search for the presence of specific antibodies. In September-October 2020, 100 HCWs were enrolled and followed up. Six subjects (6%) tested positive in saliva. Of them, 5/6 were positive in a subsequent nasopharyngeal swab and 4/6 developed signs and symptoms compatible with COVID-19. Among the latter, 3 seroconverted while asymptomatic HCWs remained seronegative. Saliva screening was helpful for identifying SARS-CoV-2 infection in HCWs. This screening permitted rapid personnel isolation avoiding further transmission of the virus in the hospital setting.

Current diagnostic standards involve severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection in nasopharyngeal swabs (NPS), but saliva is an attractive and noninvasive option for diagnosis. The objectives were to determine the performance of saliva in comparison with NPS for detecting SARS-CoV-2 and to compare the optimized home brew reverse-transcription polymerase chain reaction (RT-PCR) with a commercial RT-PCR. Paired NPS and saliva specimens were prospectively collected and tested by RT-PCR from patients presenting at an emergency room with signs and symptoms compatible with coronavirus disease-2019. A total of 348 samples from 174 patients were tested by RT-PCR assays. Among 174 patients with symptoms, 63 (36%) were SARS-CoV-2 positive in NPS using the optimized home-brew PCR. Of these 63 patients, 61 (98%) were also positive in saliva. An additional positive SARS-CoV-2 saliva was detected in a patient with pneumonia. Kappa Cohen´s coefficient agreement between NPS and saliva was 0.96 (95% confidence interval [CI], 0.90?0.99). Median Ct values in NPS versus saliva were 18.88 (interquartile range [IQR], 15.60?23.58; range, 11.97?38.10) versus 26.10 (IQR, 22.75?30.06; range, 13.78?39.22), respectively (p

BACKGROUND: Severe acute respiratory syndrome coronavirus-2 (SARS-Cov-2) producing COVID-19 disease and Dengue are both epidemic in Argentina. To date, most cases of both virus are from Buenos Aires city. Here we describe the clinical characteristics and follow up from a cohort patients coinfected with dengue and SARS-CoV-2 in Buenos Aires. METHODS: We retrospectively identified patients from different Buenos Aires area hospitals who were admitted with confirmed infection with Dengue Virus and SARS-CoV-2. Clinical data were obtained through review of medical records. Patients had at least 3 weeks follow-up. RESULTS: Thirteen patients were identified. The median age was 37 years old, most of them didn't had any comorbidity, almost half were females, and all had febrile disease at presentation The median duration of fever was 7 days. Headache was a common symptom among coinfected subjects. A total of eight patients had respiratory symptoms. Five patients had pneumonia. Three patients had rash that appear early in the course of the disease. Two of these patients had concomitant pneumonia and rash. Almost all patients had Lymphopenia at presentation and thrombocytopenia in almost half of them. No patients required ICU or died during the follow up. CONCLUSION: SARS-CoV2 and Dengue can produce coinfections in patients living in areas where both virus are epidemic. The outcome of these patients does not seem to be worse than having either SARS-Cov2 or Dengue alone. FUNDING STATEMENT: The authors stated that this article doesn´t have funding sources. DECLARATION OF INTERESTS: MES is a consultant to Basilea and the principal investigator for Argentina NIH grant UM1AI104681; all others have no interests to declare ETHICS APPROVAL STATEMENT: This study was approved by the Ethic Committee of Centro de Educacion Medica e Investigaciones Clinicas (CEMIC), Buenos Aires, Argentina.

Background SI is a significant medical problem. DFA-02 is an investigational bioresorbable modified release gel consisting of both gentamicin (16.8 mg/mL) and vancomycin (18.8 mg/mL). A Phase 2a study, where the drug was applied during surgical incision closure, suggested safety and tolerability but was not designed to assess its efficacy. Study design In a Phase 2b randomized, blinded trial patients undergoing abdominal, primarily colorectal, surgery were randomized (4:1:1) to one of three study arms: DFA-02, matching placebo gel, or standard of care (SOC) involving irrigation of the wound with normal saline. The DFA-02 and placebo gel groups received up to 20 mL of study drug inserted above the fascia during wound closure, and were treated in a double-blind manner; the SOC group was treated in a single-blind manner. The primary endpoint was SSI (adjudicated centrally by a blinded committee) through postoperative day 30. Results Overall, 445 subjects (intention-to-treat) were randomized at 35 centers with 425 subjects completing the study and being evaluable. There were 67 SSIs (15.8%): 64.2% superficial, 7.5% deep, and 28.4% organ space. The incidence of SSI was not statistically significantly different between the DFA-02 and the placebo gel/SOC arms combined, 42/287 = 14.6% vs 25/138 = 18.1% (p = 0.36), respectively. Rehospitalization within 30 days was also similar between study groups (DFA-02 28.6%, placebo gel 21.4%, SOC 27.3%). Conclusion In this multicenter, blinded, randomized trial with central adjudication, the gentamicin/vancomycin gel was not associated with a significant reduction in SSI. Summary Patients undergoing abdominal surgery were randomized to one of three study arms: DFA-02 gel consisting of both gentamicin and vancomycin, matching placebo gel, or standard of care (SOC). Of 425 patients completing the study at 35 sites the gentamicin/vancomycin gel was not associated with a significant reduction in SSI.

The broth microdilution (BMD) MIC testing method for telavancin was recently revised BMD (rBMD) to improve accuracy and reproducibility. Staphylococcus aureus isolates from telavancin phase 3 complicated skin and skin-structure infection (cSSSI) studies were tested using the rBMD method. Retesting of 1132 isolates produced MICs ranging from ≤0.015 to 0.12μg/mL that were 8-fold lower than the original method. All isolates tested remained susceptible to telavancin at the revised susceptibility breakpoint of 0.12μg/mL. The clinical cure and microbiological eradication rates were 90% (368/409) and 89% (366/409) for telavancin-treated patients, and were similar for patients with methicillin-susceptible and -resistant S. aureus isolates and S. aureus isolates with elevated vancomycin MICs (≥1μg/mL). The data presented here are aimed to update the literature and better inform clinicians and clinical microbiologists about the revised telavancin MICs, as well as the corresponding clinical and microbiological cure rates for cSSSI patients.

Two phase 3 ATLAS trials demonstrated noninferiority of telavancin compared with vancomycin for complicated skin and skin structure infections. Data from these trials were retrospectively evaluated according to 2013 U.S. Food and Drug Administration (FDA) guidance on acute bacterial skin and skin structure infections. This post hoc analysis included patients with lesion sizes of ≥75 cm 2 and excluded patients with ulcers or burns (updated all-treated population; n = 1,127). Updated day 3 (early) clinical response was defined as a ≥20% reduction in lesion size from baseline and no rescue antibiotic. Updated test-of-cure (TOC) clinical response was defined as a ≥90% reduction in lesion size, no increase in lesion size since day 3, and no requirement for additional antibiotics or significant surgical procedures. Day 3 (early) clinical responses were achieved in 62.6% and 61.0% of patients receiving telavancin and vancomycin, respectively (difference, 1.7%, with a 95% confidence interval [CI] of −4.0% to 7.4%). Updated TOC visit cure rates were similar for telavancin (68.0%) and vancomycin (63.3%), with a difference of 4.8% (95% CI, −0.7% to 10.3%). Adopting current FDA guidance, this analysis corroborates previous noninferiority findings of the ATLAS trials of telavancin compared with vancomycin.

Antimicrobial resistance in pathogenic gram-negative bacteria is one of the most pressing challenges in the field of infectious diseases and is one of 4 key areas of unmet medical need identified by the Antibacterial Resistance Leadership Group (ARLG). The mission of the Gram-Negative Committee is to advance our knowledge of these challenging infections and implement studies to improve patient outcomes. Studies have fallen primarily into 2 broad categories: prospective cohort studies and interventional trials. Among the observational studies, CRACKLE (Consortium on Resistance Against Carbapenems in Klebsiella pneumoniae and Other Enterobacteriaceae) has contributed seminal multicenter data describing risk factors and clinical outcomes of carbapenem-resistant Enterobacteriaceae (CRE) in sentinel US hospitals. Building on this success, CRACKLE II will expand the network to hospitals across the United States and Colombia. Similar protocols have been proposed to include Acinetobacter baumannii and Pseudomonas aeruginosa (SNAP and POP studies). In addition, the CREST study (Carbapenem-Resistant Enterobacteriaceae in Solid Organ Transplant Patients) has provided pivotal data on extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and CRE carriage among solid organ transplant recipients to inform management of this vulnerable patient population. Two clinical trials to define novel ways of using an existing antibiotic, fosfomycin, to treat ESBL-producing Enterobacteriaceae (one that has completed enrollment and the other in late protocol development) will determine the clinical efficacy of fosfomycin as step-down oral therapy to treat complicated urinary tract infections. Additional clinical studies and trials using immunotherapeutic or newly approved agents are also in the planning stage, with the main goals of generating actionable data that will inform clinical decision making and facilitate development of new treatment options for highly resistant gram-negative bacterial infections.

Objectives: Telavancin is approved in Europe for the treatment of nosocomial pneumonia caused by methicillinresistant Staphylococcus aureus when other alternatives are not suitable. The approved European prescribing information contraindicates the use of telavancin in patients with severe renal impairment (creatinine clearance ,30 mL/min, including patients on haemodialysis) and pre-existing acute renal failure owing to the higher observed mortality in these patients. Data from the ATTAIN studies were reanalysed, excluding patients with these contraindicating conditions at baseline. (At the time of submission of this article, the European marketing authorization of telavancin for the treatment of nosocomial pneumonia was suspended pending evidence of a new European Medicines Agency-approved supplier. Clinigen Healthcare Ltd, Theravance’s commercialization partner for telavancin in Europe, is in the process of seeking approval of a new manufacturing source.) Methods: A post hoc analysis of data from two Phase 3 ATTAIN trials of telavancin for the treatment of Grampositive nosocomial pneumonia assessing clinical outcomes and safety. Results: The all-treated population for this analysis represented 84.2% (1266/1503) of the ATTAIN all-treated population. The cure rates in the clinically evaluable population were similar in the telavancin (82.5%, 231/280) and vancomycin (81.3%, 243/299) groups [treatment difference (95% CI): 1.3% (25.0% to 7.6%)], and were consistent with the overall ATTAIN study results. The cure rate was higher in the telavancin than the vancomycin treatment group in microbiologically evaluable patients with only Gram-positive pathogens isolated at baseline [85.0% (130/153) versus 75.2% (109/145), respectively; treatment difference (95% CI): 9.7% (0.6%–18.8%)]. The incidences of adverse events were similar between treatment groups and consistent with the overall findings of the ATTAIN study. Conclusions: This analysis demonstrated that in the subset of patients without severe renal impairment or pre-existing acute renal failure, clinical and safety outcomes were similar in the telavancin and vancomycin treatment groups.

TD-1792 is a first-in-class glycopeptide-cephalosporin heterodimer that exhibits bactericidal activity against Gram-positive pathogens. We conducted a randomized, double-blind, active-control, phase II trial in patients with complicated skin and skin structure infections caused by suspected or confirmed Gram-positive organisms. Patients 18 to 65 years old were randomized to receive 7 to 14 days of either TD-1792 (2 mg/kg of body weight intravenously [i.v.] every 24 h [q24h]) or vancomycin (1 g i.v. q12h, with dosage regimens adjusted per site-specific procedures). A total of 197 patients were randomized and received at least one dose of study medication. Rates of clinical success at the test-of-cure evaluation were similar in all analysis populations. Among 170 clinically evaluable patients, cure rates were 91.7% and 90.7% in the TD-1792 and vancomycin groups, respectively (95% confidence interval [CI] of −7.9 to 9.7 for the difference). In microbiologically evaluable patients with methicillin-resistant Staphylococcus aureus at baseline ( n = 75), cure rates were 94.7% in the TD-1792 group and 91.9% in the vancomycin group. Microbiological eradication of Gram-positive pathogens ( n = 126) was achieved in 93.7% and 92.1% of patients in the TD-1792 and vancomycin groups, respectively. Seven patients were discontinued from study medication due to an adverse event (AE): 2 and 5 in the TD-1792 and vancomycin groups, respectively. AEs were of similar types and severities between the two groups, other than pruritus, which was more common in patients who received vancomycin. No patients in the TD-1792 group experienced a serious AE. This study supports further clinical development of TD-1792 in patients with Gram-positive infection.

PURPOSE: Although Staphylococcus aureus is a leading cause of nosocomial infection, little is known about the impact of S. aureus bacteremia on patients with prosthetic devices. This investigation sought to define the clinical outcome, health care resource use, and infection-associated costs of S. aureus bacteremia in patients with prostheses. SUBJECTS AND METHODS: All hospitalized patients with a prosthetic device and S. aureus bacteremia during the 96-month study period were identified prospectively. Clinical data were collected at the time of hospitalization. Data regarding infection-related resource utilization and infection-related costs within 12 weeks of the initial bacteremia were also recorded. RESULTS: 298 patients with > or =1 prosthesis and S. aureus bacteremia were identified (cardiovascular device--122 patients, orthopedic device--73 patients, long-term catheter--71 patients, and other devices-32 patients). Overall, 58% of patients underwent surgery as a consequence of the infection. Infection-related complications occurred in 41% and the overall 12-week mortality was 27%. The mean infection-related cost was 67439 dollars for patients with hospital-acquired S. aureus bacteremia and 37868 dollars for community-acquired S. aureus bacteremia (cost difference 29571 dollars; 95% confidence interval, 14370 dollars-49826 dollars). Rates of device infection, complications, 12-week mortality, and mean cost varied by prosthesis type. CONCLUSION: S. aureus bacteremia in patients with prosthetic devices is associated with frequent complications, substantial cost, and significant health care resource utilization.

Objective:Comorbid conditions have complicated previous analyses of the consequences of methicillin resistance for costs and outcomes ofStaphylococcus aureusbacteremia. We compared costs and outcomes of methicillin resistance in patients withS. aureusbacteremia and a single chronic condition.Design, Setting, and Patients:We conducted a prospective cohort study of hemodialysis-dependent patients with end-stage renal disease andS. aureusbacteremia hospitalized between July 1996 and August 2001. We used propensity scores to reduce bias when comparing patients with methicillin-resistant (MRSA) and methicillin-susceptible (MSSA)S. aureusbacteremia. Outcome measures were resource use, direct medical costs, and clinical outcomes at 12 weeks after initial hospitalization.Results:Fifty-four patients (37.8%) had MRSA and 89 patients (62.2%) had MSSA. Compared with patients with MSSA bacteremia, patients with MRSA bacteremia were more likely to have acquired the infection while hospitalized for another condition (27.8% vs 12.4%;P= .02). To attribute all inpatient costs toS. aureusbacteremia, we limited the analysis to 105 patients admitted for suspectedS. aureusbacteremia from a community setting. Adjusted costs were higher for MRSA bacteremia for the initial hospitalization ($21,251 vs $13,978;P= .012) and after 12 weeks ($25,518 vs $17,354;P= .015). At 12 weeks, patients with MRSA bacteremia were more likely to die (adjusted odds ratio, 5.4; 95% confidence interval, 1.5 to 18.7) than were patients with MSSA bacteremia.Conclusions:Community-dwelling, hemodialysis-dependent patients hospitalized with MRSA bacteremia face a higher mortality risk, longer hospital stays, and higher inpatient costs than do patients with MSSA bacteremia.

Ceftaroline has in vitro activity against bacterial isolates, including methicillin-resistant Staphylococcus aureus. This is the first study to investigate ceftaroline fosamil in pediatric patients with acute bacterial skin and skin structure infections (ABSSSIs).A multicenter, observer-blinded study (NCT01400867) in pediatric patients (2 months-17 years of age) with ABSSSIs. Patients were randomized 2:1 to receive intravenous (IV) ceftaroline fosamil or IV comparator (vancomycin or cefazolin, plus optional aztreonam) with optional switch to oral antibacterials from Day 4. Safety and clinical outcomes were assessed.Of 163 enrolled patients, 159 received treatment. Treatment groups were comparable for baseline characteristics. Rates of study drug-related treatment-emergent adverse events were similar for ceftaroline fosamil [22% (23/106)] and comparator [23% (12/53)]. One serious adverse event, considered to be related to IV study drug, occurred in the ceftaroline fosamil group (hypersensitivity). In both the treatment groups, 85% (ceftaroline fosamil, 91/107 and comparator, 44/52) of the modified intent-to-treat population achieved early clinical response (≥20% reduction in infection area from baseline). Clinical cure rates at test-of-cure were high [ceftaroline fosamil, 94% (101/107) and comparator, 87% (45/52)]. For patients evaluated 8 to 15 days after the last dose of any antibiotic (IV or oral), from whom methicillin-resistant Staphylococcus aureus was initially isolated, a favorable microbiologic response (reflecting the efficacy of oral/IV therapy and capturing a relapse or reinfection) was achieved with ceftaroline fosamil [89% (16/18)] and comparator [57% (4/7)].Ceftaroline fosamil, with optional oral switch, was as well-tolerated and effective in pediatric patients with ABSSSIs as comparator therapy.

Treatment options for hospital-acquired pneumonia caused by Gram-positive organisms are far from ideal. The increase in vancomycin MICs among methicillin-resistant Staphylococcus aureus (MRSA) isolates, and the slow bactericidal action and poor lung penetration of vancomycin have driven the search for an alternative agent. Telavancin, a once-daily lipoglycopeptide, displays strong bactericidal activity against S. aureus. Two large Phase III randomized trials have recently compared intravenous telavancin (10 mg/kg every 24 h) with vancomycin (1 g intravenously every 12 h) for 7-21 days for the treatment of hospital-acquired pneumonia caused by Gram positives. No significant differences were observed in the cure rates in the all-treated (n = 1503), the clinically evaluable (n = 654) and the microbiologically evaluable (n =480) populations. Telavancin performed better than vancomycin in patients with monomicrobial S. aureus pneumonia (84.2 vs 74.3%; 95% CI: 0.7-19.1), with MRSA (81.8 vs 74.1%; 95% CI: -3.5 to 19.3), and with strains having vancomycin MICs ≥1 µg/ml (87.1 vs 74.3; 95% CI: 0.5-23). The rate of adverse events, including serious adverse events, was similar in both groups, with a slightly higher rate of serum creatinine increase in the telavancin-treated group. Based on these results, telavancin (already approved for this indication by the EMA) could certainly be added to the current treatment options, particularly in patients with MRSA pneumonia.

†Deceased. Received 27 October 2011; returned 4 December 2011; revised 7 February 2012; accepted 18 February 2012 Background: Telavancin is approved in the USA and Canada for the treatment of Gram-positive complicated skin and skin structure infections (cSSSIs) based on the results of the Phase 3 Assessment of TeLAvancin in complicated Skin and skin structure infections (ATLAS) trials, which demonstrated non-inferiority of telavancin to vancomycin. Methods: We conducted a post hoc analysis of the ATLAS studies (ClinicalTrials.gov identifiers NCT00091819 and NCT00107978) to explore the efficacy of telavancin in patients with various types of cSSSIs. Results: A total of 1794 patients were included in this analysis; 1434 patients were clinically evaluable (CE) and 563 of these had methicillin-resistant Staphylococcus aureus (MRSA). Among CE patients with major abscesses (n¼ 619), cure rates were 91% for telavancin and 90% for vancomycin (95% CI for the difference 23.6 to 5.7). In patients with infective cellulitis (n¼ 519), cure was achieved in 87% and 88% of telavancin- and vancomycintreated patients, respectively (95% CI for the difference 26.2 to 5.2). Cure rates in patients with wound infections were 85% in the telavancin group and 86% in the vancomycin group (95% CI for the difference 210.5 to 9.0). Cure rates for each type of cSSSI in patients infected with MRSA were also similar between the two treatment arms. Among CE patients infected with Panton –Valentine leucocidin (PVL)-positive MRSA (n¼ 447), cure rates were 93% for telavancin and 90% for vancomycin (95% CI for the difference 22.2 to 8.2). Conclusions: Cure rates were similar for telavancin and vancomycin in patients with different types of cSSSIs, including infections caused by MRSA and PVL-positive strains of MRSA.

Hospital-acquired pneumonia (HAP) is the second most common nosocomial infection and the leading cause of mortality attributable to these critical infections [ 1– 3]. Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), is now a major cause of HAP [ 4– 6]. Rates of clinical failure in patients with HAP due to MRSA are high [ 7, 8]. Currently, only vancomycin and linezolid are recommended for treatment of HAP due to MRSA [ 9]. Results from recent pneumonia trials with new antibiotics active against MRSA have not been encouraging [ 10– 12]. Therefore, additional antistaphylococcal agents for treatment of HAP are urgently needed. Telavancin is a lipoglycopeptide antibacterial agent exhibiting potent, concentration-dependent bactericidal effects via a dual mechanism of action that combines inhibition of cell wall synthesis and disruption of membrane barrier function [ 13– 15]. In vitro, telavancin is rapidly bactericidal against clinically important gram-positive bacteria, including MRSA, vancomycin-intermediate S. aureus, and penicillin-resistant S. pneumoniae [ 13, 16, 17]. Telavancin penetrates well into the epithelial lining fluid and alveolar macrophages of healthy subjects, achieving concentrations up to 8-fold and 85-fold, respectively, above telavancin's minimum inhibitory concentration (MIC) for 90% (MIC90) of MRSA strains (.5 μg/mL) [ 16, 18]. Unlike daptomycin (a cyclic lipopeptide), telavancin remains active in vitro in the presence of pulmonary surfactant [ 16]. Telavancin is approved in the United States and Canada for the treatment of adult patients with complicated skin and skin-structure infections due to susceptible gram-positive pathogens. The current studies were designed to assess the clinical efficacy and safety of telavancin compared with vancomycin in the treatment of HAP due to gram-positive organisms, with a focus on infections due to MRSA. Partial results of these studies have been previously reported.

Data on the clinical presentation, risk factors, and outcomes for healthcare personnel (HCP) infected with influenza A H1N1 virus (H1N1) are limited. From June to July 2009, a prospective study was conducted among HCP with influenza-like illness (ILI) at university hospitals in Buenos Aires. A reverse transcription polymerase chain reaction (RT-PCR) was used to diagnose H1N1. A logistic regression model was developed to identify factors associated with H1N1. Among 1519 HCP, 96 (6.3%) were diagnosed with an ILI. Of these, 85 (88.5%) were swabbed for H1N1 detection, with 43 positive cases (2.8%). Seasonal influenza immunization was recorded in 76%. Comparison of H1N1-positive vs. H1N1-negative cases showed that H1N1-positive cases more frequently had asthenia (72% vs. 48%, p = 0.03) and cough (79% vs. 43%, p = 0.008) and less frequently had diarrhoea (9% vs. 29%, p = 0.03) and prior prophylaxis with oseltamivir (5% vs. 31%, p = 0.002). The logistic regression model showed that presence of cough (odds ratio (OR) 6.93, 95% confidence interval (CI) 2.24, 21.4) was associated with an increased risk of H1N1. Prior prophylaxis with oseltamivir (OR 0.08, 95% CI 0.01, 0.43) was associated with a lower probability of H1N1 infection. A high proportion of HCP with an ILI were infected with H1N1. Complication rates were relatively low. Prior prophylaxis with oseltamivir was associated with a lower risk of developing H1N1.

A dramatic increase in infections caused by methicillin-resistant Staphylococcus aureus (MRSA) has been observed, in part as a result of the epidemic of community-associated MRSA skin and skin-structure infections (SSSIs). Simultaneously, decreasing sensitivities of S. aureus to vancomycin have been reported and invasive infections caused by these strains have been associated with worse clinical outcomes. Clearly, new agents active against MRSA are needed. Ceftaroline is a new cephalosporin active against MRSA and many Gram-negative bacteria, though it is not active against Pseudomonas spp. and extended spectrum beta-lactamase producers (ESBL).In this review we focus on the properties of ceftaroline such as in vitro activity, the pharmacokinetic and pharmacodynamic characteristics, and its efficacy and safety observed in the clinical trials of patients with SSSI. Finally, we provide an overview of the possible future role of ceftaroline and other compounds in development for the treatment of SSSIs. The literature search was based on PubMed articles plus review of the abstracts presented in the most important international conferences in the field.The reader will gain clear concepts to understand the value that ceftaroline might have in the treatment of SSSIs, including those caused by MRSA.Ceftaroline has shown bactericidal activity against common pathogens associated with SSSIs including MRSA, noninferiority in clinical trials of patients with complicated SSSI (cSSSI), and a favorable safety profile.

The role of Panton-Valentine leukocidin (PVL) in determining the severity and outcome of complicated skin and skin structure infections (cSSSI) caused by methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) is controversial. We evaluated potential associations between clinical outcome and PVL status by using MRSA isolates from patients enrolled in two large, multinational phase three clinical trials assessing telavancin for the treatment of cSSSI (the ATLAS program). MRSA isolates from microbiologically evaluable patients were genotyped by pulsed-field gel electrophoresis (PFGE) and PCR for pvl and 31 other putative virulence determinants. A single baseline pathogen of MRSA was isolated from 522 microbiologically evaluable patients (25.1%) among 2,079 randomized patients. Of these MRSA isolates, 83.2% (432/519) exhibited the USA300 PFGE genotype and 89.1% (465/522) were pvl positive. Patients with pvl -positive MRSA were more likely than those with pvl -negative MRSA to be young, to be North American, and to present with major abscesses ( P < 0.001 for each). Patients were significantly more likely to be cured if they were infected with pvl -positive MRSA than if they were infected with pvl -negative MRSA (91.6% versus 80.7%; P = 0.015). This observation remained statistically significant after adjustment for presence of abscess, fever, or leukocytosis; infection size; diabetes; patient age; and study medication received. The fnbA , cna , sdrC , map-eap , sed , seg , sei , sej , SCC mec type IV, and agr group II genes were also associated with clinical response ( P < 0.05). This contemporary, international study demonstrates that pvl was not the primary determinant of outcome in patients with MRSA cSSSI.

Purpose of review Methicillin-resistant Staphylococcus aureus (MRSA) is a dynamic pathogen. Rates of MRSA are increasing worldwide. In some centers, MRSA is becoming less susceptible to vancomycin, and these strains have been associated with worse clinical outcomes. Intermediate or fully resistant vancomycin strains of MRSA have emerged clinically, whereas MRSA acquired in the community has become epidemic. The purpose of this manuscript is to provide clinicians with an evidence-based review on new treatments for MRSA. Recent findings Linezolid, daptomycin and tigecycline have been approved during the last decade to treat infections due to MRSA. Although these agents are extremely valuable in the fight against MRSA, each one has limitations. New lypoglycopeptides (telavancin, dalbavancin and oritavancin) are in advanced phase of clinical development. Similarly, new broad-spectrum cephalosporins active against MRSA (e.g. ceftobiprole and ceftaroline) and a new dihydrofolate reductase inhibitor (iclaprim) are in or have completed phase 3 studies. Summary Here, we review the most relevant information on new drugs to treat MRSA. New studies with available agents and upcoming studies with investigational drugs will help to better understand the role of each compound in the treatment of patients infected with MRSA and assist the clinician in keeping pace with this challenging pathogen.

Udgivelsesdato: 2010-Jan Tuberculosis (TB) is a global public health problem and a source of preventable deaths each year, with 8.8 million new cases of TB and 1.6 million deaths worldwide in 2005. Approximately, 10% of infected individuals develop pulmonary or extrapulmonary TB, suggesting that host defense factors influence development of active disease. Toll-like receptor' (TLR) polymorphisms have been associated with regulation of TLR expression and development of active TB. In the present study, 71 polymorphisms in TLR1, TLR2, TLR4, TLR6, and TLR9 were examined from 474 (295 cases and 179 controls) African-Americans, 381 (237 cases and 144 controls) Caucasians, and from 667 (321 cases and 346 controls) Africans from Guinea-Bissau for association with pulmonary TB using generalized estimating equations and logistic regression. Statistically significant associations were observed across populations at TLR9 and TLR2. The strongest evidence for association came at an insertion (I)/deletion (D) polymorphism (-196 to -174) in TLR2 that associated with TB in both Caucasians (II vs. ID&DD, OR = 0.41 [95% CI 0.24-0.68], p = 0.0007) and Africans (II vs. ID&DD, OR = 0.70 [95% CI 0.51-0.95], p = 0.023). Our findings in three independent population samples indicate that variations in TLR2 and TLR9 might play important roles in determining susceptibility to TB.

Methicillin (meticillin)-susceptible Staphylococcus aureus (MSSA) strains producing large amounts of type A β-lactamase (Bla) have been associated with cefazolin failures, but the frequency and impact of these strains have not been well studied. Here we examined 98 MSSA clinical isolates and found that 26% produced type A Bla, 15% type B, 46% type C, and none type D and that 13% lacked blaZ . The cefazolin MIC 90 was 2 μg/ml for a standard inoculum and 32 μg/ml for a high inoculum, with 19% of isolates displaying a pronounced inoculum effect (MICs of ≥16 μg/ml with 10 7 CFU/ml) (9 type A and 10 type C Bla producers). At the high inoculum, type A producers displayed higher cefazolin MICs than type B or C producers, while type B and C producers displayed higher cefamandole MICs. Among isolates from hemodialysis patients with MSSA bacteremia, three from the six patients who experienced cefazolin failure showed a cefazolin inoculum effect, while none from the six patients successfully treated with cefazolin showed an inoculum effect, suggesting an association between these strains and cefazolin failure ( P = 0.09 by Fisher's exact test). In summary, 19% of MSSA clinical isolates showed a pronounced inoculum effect with cefazolin, a phenomenon that could explain the cases of cefazolin failure previously reported for hemodialysis patients with MSSA bacteremia. These results suggest that for serious MSSA infections, the presence of a significant inoculum effect with cefazolin could be associated with clinical failure in patients treated with this cephalosporin, particularly when it is used at low doses.

Tuberculosis (TB) has substantial mortality worldwide with 5-10% of those exposed progressing to active TB disease. Studies in mice and humans indicate that the inducible nitric oxide synthase (iNOS) molecule plays an important role in immune response to TB. A mixed case-control association study of individuals with TB, relatives, or close contact controls was performed in 726 individuals (279 case and 166 control African-Americans; 198 case and 123 control Caucasians). Thirty-nine single nucleotide polymorphisms (SNPs) were selected from the NOS2A gene for single SNP, haplotype, and multilocus interaction analyses with other typed candidate genes using generalized estimating equations. In African-Americans, ten NOS2A SNPs were associated with TB. The strongest associations were observed at rs2274894 (odds ratio (OR) = 1.84, 95% confidence interval (CI) [1.23-2.77], p = 0.003) and rs7215373 (OR 1.67, 95% CI [1.17-2.37], p = 0.004), both of which passed a false discovery rate (FDR) correction for multiple comparisons (q*=0.20). The strongest gene-gene interactions were observed between NOS2A rs2248814 and IFNGR1 rs1327474 (p = 0.0004) and NOS2A rs944722 and IFNGR1 rs1327474 (p = 0.0006). Three other SNPs in NOS2A interacted with TLR4 rs5030729 and five other NOS2A SNPs interacted with IFNGR1 rs1327474. No significant associations were observed in Caucasians. These results suggest that NOS2A variants may contribute to TB susceptibility, particularly in individuals of African descent, and may act synergistically with SNPs in TLR4 and IFNGR1.

Background and objectives: Staphylococcus aureus is a leading cause of infection in patients with ESRD. Clinical and economic outcomes associated with S. aureus bacteremia and other S. aureus infections in patients with ESRD were examined. Design, setting, participants, & measurements: Laboratory, clinical, and hospital billing data from a randomized trial of 3359 hemodialysis-dependent patients hospitalized with S. aureus infection in the United States whose vascular access type was fistula or graft and who were hospitalized with S. aureus infection to evaluate inpatient costs, hospital days, and mortality over 12 wk were used. Generalized linear regression was used to identify independent predictors of 12-wk costs, inpatient days, and mortality. Results: Of the 279 patients (8.3%) who developed S. aureus infection during approximately 1 yr of follow-up, 25.4% were treated as outpatients. Among patients for whom billing data were available, 89 patients hospitalized with S. aureus bacteremia incurred mean 12-wk inpatient costs of $19,454 and 11.9 inpatient days. Among the 70 patients hospitalized with non-bloodstream S. aureus infections, mean inpatient costs were $19,222 and the mean number of inpatient days was 11.3. Twelve-week mortality was 20.2 and 15.7% for patients with S. aureus bloodstream and non-bloodstream infections, respectively. Older age was independently associated with higher risk of death among patients with S. aureus bacteremia and with higher inpatient costs and more hospital days among patients with non-bloodstream infections. Conclusions: Hemodialysis-dependent patients with fistula or graft access incur high costs and long inpatient stays when hospitalized for S. aureus infection.

Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infection has become epidemic. Skin and soft-tissue infections (SSTIs) are the most frequent forms of the disease. Obtainment of culture specimens is important for documentation of the presence of MRSA and for susceptibility testing to guide therapy. Purulent lesions should be drained whenever possible. In areas where community-acquired MRSA isolates are prevalent, uncomplicated SSTI in healthy individuals may be treated empirically with clindamycin, trimethoprim-sulfamethoxazole, or long-acting tetracyclines, although specific data supporting the efficacy of these treatments are lacking. In healthy patients with small purulent lesions, drainage alone may be sufficient. In patients with complicated SSTI requiring hospitalization or intravenous therapy, vancomycin is the drug of choice because of the low cost, efficacy, and safety. Linezolid, daptomycin, and tigecycline are also effective, although published studies on the last 2 agents for the treatment of SSTI due to MRSA are more limited. Dalbavancin, telavancin, and ceftobiprole are investigational agents that may expand our therapeutic options for the treatment of SSTI caused by MRSA.

Like most physicians, we have developed our clinical skills by caring for patients, reading, discussing with other clinicians, and watching our mentors at work. Also, like most experienced clinicians, we rely on a relatively small number of basic rules repeatedly to guide our decisions in everyday practice. In fact, our daily clinical practice relies as much on this passed-down wisdom as on scientific data. These and other hard-won insights about the often-mysterious process of clinical decision making have traditionally been transmitted from physician to physician by example and via hallway conversation rather than via the written word. These rules are not meant to be definitive but have been put forward to encourage dialogue between clinicians about the process of clinical care and provide trainees with some useful guideposts in learning their way in the world of clinical practice.

Because of its ease of dosing, vancomycin is commonly used to treat methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia in patients undergoing long-term hemodialysis. Clinical outcomes resulting from such a therapeutic strategy have not been well defined.We prospectively identified patients undergoing long-term hemodialysis who received a diagnosis of MSSA bacteremia. Clinical outcomes were grouped according to the predominant antibiotic received during their therapy (vancomycin or a first-generation cephalosporin [cefazolin]). Treatment failure (defined as death or recurrent infection) was determined at 12 weeks after the initial positive blood culture results. A multivariable analysis was used to adjust for confounders.During an 84-month period, 123 hemodialysis-dependent patients with MSSA bacteremia were identified. Patients receiving vancomycin (n=77) tended to be younger (51 vs. 57 years; P=.06) and had a lower rates of metastatic complications at presentation (11.7% vs. 36.7%; P=.001) than did those receiving cefazolin (n=46). The 2 groups were similar with regard to Acute Physiology and Chronic Health Evaluation II scores, comorbidities, source of infection, type of hemodialysis access, and access removal rates. Treatment failure was more common among patients receiving vancomycin (31.2% vs. 13%; P=.02). In the multivariable analysis, factors independently associated with treatment failure included vancomycin use (odds ratio, 3.53; 95% confidence interval, 1.15-13.45) and retention of the hemodialysis access (odds ratio, 4.99; 95% confidence interval, 1.89-13.76).Hemodialysis-dependent patients with MSSA bacteremia treated with vancomycin are at a higher risk of experiencing treatment failure than are those receiving cefazolin. In the absence of patient specific circumstances (e.g., allergy to beta-lactams), vancomycin should not be continued beyond empirical therapy for hemodialysis-dependent patients with MSSA bacteremia.

BACKGROUND When hospital-acquired or ventilator-associated bacterial pneumonia (HABP/VABP) is caused by gram-positive and gram-negative pathogens or both (mixed infections), the adequacy of gram-negative coverage (GNC) can confound the assessment of a gram-positive agent under study. This analysis examines the influence of gram-negative infections and the adequacy of GNC on clinical efficacy and all-cause mortality in the telavancin HABP/VABP phase 3 ATTAIN trials (Assessment of Telavancin for Treatment of Hospital-Acquired Pneumonia). METHODS This post hoc analysis evaluated 3 patient groups from ATTAIN: (1) gram-positive-only infections, (2) gram-positive-only and mixed infections-adequate GNC, and (3) gram-negative-only infections and mixed infections with inadequate GNC. For each, clinical efficacy at test of cure and all-cause mortality at day 28 were compared for telavancin and vancomycin. RESULTS/CONCLUSIONS In the ATTAIN safety population there were 16 more deaths in the telavancin arms than in the vancomycin arms. Of these, 13 were in patients with gram-negative-only infections (n = 9) or with mixed infections and inadequate GNC (n = 4) and all had estimated baseline creatinine clearances of

Experimental models and limited clinical data support a potential role for telavancin, a bactericidal lipoglycopeptide antibiotic, for treatment of Staphylococcus aureus bacteremia (SAB). Additional clinical experience is needed to fully assess use of telavancin for SAB., Staphylococcus aureus bacteremia (SAB) is one of the most common serious bacterial infections and the most frequent invasive infection due to methicillin-resistant S. aureus (MRSA). Treatment is challenging, particularly for MRSA, because of limited treatment options. Telavancin is a bactericidal lipoglycopeptide antibiotic that is active against a range of clinically relevant gram-positive pathogens including MRSA. In experimental animal models of sepsis telavancin was shown to be more effective than vancomycin. In clinically evaluable patients enrolled in a pilot study of uncomplicated SAB, cure rates were 88% for telavancin and 89% for standard therapy. Among patients with infection due to only gram-positive pathogens enrolled in the 2 phase 3 studies of telavancin for treatment of hospital-acquired pneumonia, cure rates for those with bacteremic S. aureus pneumonia were 41% (9/22, telavancin) and 40% (10/25, vancomycin) with identical mortality rates. These data support further evaluation of telavancin in larger, prospective studies of SAB.

International audience; Background - The impact of early valve surgery (EVS) on the outcome of Staphylococcus aureus (SA) prosthetic valve infective endocarditis (PVIE) is unresolved. The objective of this study was to evaluate the association between EVS, performed within the first 60 days of hospitalization, and outcome of SA PVIE within the International Collaboration on Endocarditis-Prospective Cohort Study. Methods - Participants were enrolled between June 2000 and December 2006. Cox proportional hazards modeling that included surgery as a time-dependent covariate and propensity adjustment for likelihood to receive cardiac surgery was used to evaluate the impact of EVS and 1-year all-cause mortality on patients with definite left-sided S. aureus PVIE and no history of injection drug use. Results - EVS was performed in 74 of the 168 (44.3%) patients. One-year mortality was significantly higher among patients with S. aureus PVIE than in patients with non-S. aureus PVIE (48.2% vs 32.9%; P = .003). Staphylococcus aureus PVIE patients who underwent EVS had a significantly lower 1-year mortality rate (33.8% vs 59.1%; P = .001). In multivariate, propensity-adjusted models, EVS was not associated with 1-year mortality (risk ratio, 0.67 [95% confidence interval, .39-1.15]; P = .15). Conclusions - In this prospective, multinational cohort of patients with S. aureus PVIE, EVS was not associated with reduced 1-year mortality. The decision to pursue EVS should be individualized for each patient, based upon infection-specific characteristics rather than solely upon the microbiology of the infection causing PVIE.

Incidences of osteomyelitis caused by Staphylococcus aureus have increased dramatically in recent years, in part, due to the appearance of community-acquired antibiotic-resistant strains. Therefore, understanding the pathogenesis of this organism has become imperative. Recently, we have described the surprising ability of bone-forming osteoblasts to secrete a number of important immune mediators when exposed to S. aureus in vitro. In the present study, we provide the first evidence for the in vivo production of the pivotal inflammatory chemokine, monocyte chemoattractant protein-1 (MCP-1), by osteoblasts during S. aureus-associated bone infection. Quantitative real-time PCR was employed to determine levels of mRNA encoding MCP-1 in vivo using a mouse model that closely resembles the pathology of trauma-induced staphylococcal osteomyelitis. Expression of this inflammatory chemokine and osteoblast-specific markers was investigated by confocal laser scanning microscopy in bone tissue from organ cultures of neonatal mouse calvaria and from the in vivo mouse model. Furthermore, the clinical relevancy of these findings was investigated by performing similar studies on infected human bone tissue from patients with S. aureus-associated osteomyelitis. Here, we confirm that expression of mRNA encoding MCP-1 is elevated in bacterially infected murine bone tissue. Importantly, we show that these increases translate into marked elevations in the expression of MCP-1 protein that co-localizes with osteoblast markers in infected bone tissue. Such increases could not be attributed solely to mechanical damage as a similar response was observed in infected but otherwise undamaged organ cultures. Finally, we have demonstrated the in vivo production of MCP-1 by osteoblasts in bone specimens from patients with S. aureus-associated osteomyelitis. As such, these studies demonstrate that bacterial challenge of osteoblasts during bone diseases such as staphylococcal osteomyelitis induces cells to produce a key inflammatory chemokine that can direct appropriate host responses or may contribute to progressive inflammatory damage.

Purpose Staphylococcus aureus is a common cause of bacteremia and of native valve infective endocarditis. However, the risk of endocarditis in patients with a prosthetic valve who develop S. aureus bacteremia is unclear. The aim of this study was to define the risk of prosthetic valve endocarditis in patients with S. aureus bacteremia. Subjects and methods All patients with a prosthetic valve or ring who developed S. aureus bacteremia during the 94-month study period were prospectively evaluated. The modified Duke criteria were used for the diagnosis of endocarditis. Patients were followed up for 12 weeks after the initial diagnosis of S. aureus bacteremia. Results The overall rate of definite prosthetic valve endocarditis among the study patients was 26/51 (51%). The risk of endocarditis was similar in patients with late (≥12 months after valve implantation) vs. early S. aureus bacteremia ( P =1.0), mitral vs. aortic prostheses (62% vs. 48%, P =0.24), and mechanical vs. bioprosthetic valves (62% vs. 44%, P =0.29). The 12-week mortality was higher among patients with definite vs. possible endocarditis (62% vs. 28%, P =0.019). Conclusion In this investigation, approximately half of all patients with prosthetic valves who developed S. aureus bacteremia had definite endocarditis. The risk of endocarditis was independent of the type, location, or age of the prosthetic valve. The mortality of prosthetic valve endocarditis is high. All patients with a prosthetic valve who develop S. aureus bacteremia should be aggressively screened and followed for endocarditis.

Sir, JNJ-Q2 is a fifth-generation fluoroquinolone with in vitro coverage of community-acquired bacterial pneumonia (CABP) pathogens, atypical respiratory pathogens, multidrug-resistant Streptococcus pneumoniae and methicillin-resistant Staphylococcus aureus. This double-blind, randomized, non-inferiority, ethics-approved study was designed to enrol 120 hospitalized and consented CABP subjects at 60 sites. It was done in accordance with international guidelines and was based on the 2009 FDA CABP guidance,1 with the following two exceptions: (i) one dose of a short-acting antibiotic within 4 h before randomization; and (ii) mandatory requirement for sputum production. Patients aged 18–85 years with a PORT score of ≥II and at least three CABP signs/symptoms were eligible for enrolment (cough, dyspnoea/tachypnoea, chest pain, fever/hypothermia or pulmonary consolidation). Sputum with a positive Gram's stain and a chest X-ray (CXR) showing infiltrates in at least lobar distribution were required for entry. Subjects were stratified by PORT score (II/III versus IV/V) and age (1200 patients in 24 months at 303 centres, only 2% of their population came from the USA.7 Respiratory pathogen recovery rate was unusually high. Sputum PCR testing remains an experimental tool8 and requires that clinicians distinguish between colonization and infection. In our study, each patient with S. pneumoniae PCR-positive sputum had ≥5.3 × 104 copies per mL, exceeding the rate recommended by Yang et al.9 Compared with historical pathogen identification rates (generally

Background The causes of persistent bacteremia (PB) due to methicillin-resistant Staphylococcus aureus (MRSA) are poorly understood. This investigation examined potential associations between PB with key clinical features and several in vitro bacterial genotypic and phenotypic characteristics, in isolates from 1 institution. Methods Pulsed-field gel electrophoresis (PFGE) relatedness, thrombin-induced platelet microbicidal protein (tPMP)-susceptibility phenotype, accessory gene regulator (agr) genotype and functionality (via delta-lysin production), and autolysis phenotypes were assessed in MRSA isolates from the bloodstream of 21 prospectively identified patients with PB (blood cultures positive after > or =7 days of therapy) and of 18 patients with resolving bacteremia (RB) (sterile blood cultures within the first 2-4 days of therapy) due to MRSA. Results The 2 groups had comparable baseline characteristics but differed in their clinical courses (e.g., endocarditis was more frequent in patients with PB than in those with RB [43% vs. 0%, respectively; P=.0016]); isolates from patients with PB exhibited higher rates of (1) survival in vitro after exposure to tPMP (22.4+/-14.8% vs. 11.6+/-6.5%, respectively; P=.005); (2) defective delta-lysin production (71.4% vs. 38.9%, respectively; P=.057); (3) non-agr genotype II profile (100% vs. 77.8%, respectively; P=.037); and (4) overrepresentation of a specific PFGE genotype (85.7% vs. 44.4%, respectively; P=.015). Conclusions Isolates from patients with PB differed from those in patients with RB, in several in vitro characteristics. Further studies will be necessary to define how these factors might affect clinical outcome.

Staphylococcus aureus is the single most common cause of osteomyelitis in humans. Incidences of osteomyelitis caused by S. aureus have increased dramatically in recent years, in part due to the appearance of community-acquired antibiotic resistant strains. Therefore, understanding the pathogenesis of this organism has become imperative. Recently, we have described the surprising ability of bone-forming osteoblasts to secrete a number of important immune mediators when exposed to S. aureus in vitro. In the present study, we provide the first evidence for the in vivo production of such molecules by osteoblasts during bacterial infection of bone. These studies demonstrate the expression of the key inflammatory cytokine interleukin-6 by osteoblasts in organ cultures of neonatal mouse calvaria, and in vivo using a mouse model that closely resembles the pathology of trauma-induced staphylococcal osteomyelitis, as determined by confocal microscopic analysis. Importantly, we have established the clinical relevancy of these findings in infected human bone tissue from patients with S. aureus-associated osteomyelitis. As such, these studies demonstrate that bacterial challenge of osteoblasts during bone diseases, such as osteomyelitis, induces cells to produce inflammatory molecules that can direct appropriate host responses or contribute to progressive inflammatory damage.

Ceftaroline fosamil was approved in 2010 by the United States Food and Drug Administration (USA-FDA) for the treatment of patients with acute bacterial skin and skin structure infections (ABSSSIs) and community-acquired bacterial pneumonia (CABP). After approval, several studies and case reports have described the postmarketing clinical experience with ceftaroline in ABSSSIs and CABP and in patients with invasive methicillin-resistant Staphylococcus aureus (MRSA) infections, many of whom had failed prior antibiotics. Successful clinical outcomes observed among the majority of these patients were supported by preapproval and postapproval in vitro surveillance of ceftaroline activity using breakpoint criteria that have been harmonized between the USA-FDA and CLSI. MIC90 values/percentage of strains susceptible to ceftaroline has remained stable over the period 2009-2012. Taken together, these postapproval studies support the use of ceftaroline for ABSSSI as well as CABP. Importantly, these data also suggest that ceftaroline can be effective in patients with serious invasive MRSA infections who have failed other therapies.

Using 98 clinical methicillin-susceptible Staphylococcus aureus isolates of known β-lactamase (Bla) type, we found a pronounced inoculum effect for cephalexin (mostly Bla type A and C strains), a mild inoculum effect for cephalothin (especially types B and C), and no inoculum effects for ceftriaxone and cefuroxime. Ceftobiprole showed the lowest MICs at a high inoculum but with a slight increase for Bla-positive versus Bla-negative strains. Since a potential therapeutic effect associated with a cephalosporin inoculum effect has been described, further studies are warranted.

The horizontal transmission of methicillin resistance to Staphylococcus aureus (MRSA) in hospital and community settings, and growing prevalence of these strains, presents a significant clinical challenge to the management of serious infections worldwide. While infection control initiatives have stemmed the rising prevalence, MRSA remains a significant pathogen. More recently, evidence that MRSA is becoming resistant to glycopeptides and newer therapies raises concern about the use of these therapies in clinical practice. Vancomycin resistance has become evident in select clinical settings through rising MICs, growing awareness of heteroresistance, and emergence of intermediate-resistant and fully resistant strains. While resistance to linezolid and daptomycin remains low overall, point mutations leading to resistance have been described for linezolid, and horizontal transmission of cfr-mediated resistance to linezolid has been reported in clinical isolates. These resistance trends for newer therapies highlight the ongoing need for new and more potent antimicrobial therapies.