Clinical management of Staphylococcus aureus bacteremia: a review

Evaluation of Staphylococcus aureus Bacteremia: Academic and Community-Based Management Within the Same Health System

A nonrandomized, retrospective comparison of Staphylococcus aureus bacteremia between an academic hospital setting (n=53) and a community hospital setting (n=245) within a single healthcare system was performed. Despite infectious disease consultations, S. aureus bacteremia management recommendations based on Infectious Diseases Society of America (IDSA) guidelines were not followed as closely in the community hospital setting. The community hospital setting requires management standardization for patients with S. aureus bacteremia. Infect Control Hosp Epidemiol 2017;38:740-742.

The "Choosing Wisely" initiative in infectious diseases

OBJECTIVE

"Choosing Wisely" is a growing international campaign aiming at practice changes to improve patient health and safety by both, conduct of essential and avoidance of unnecessary diagnostic, preventive and therapeutic procedures. The goal is to create an easily recognizable and distributable list ("Choosing Wisely items") that addresses common over- and underuse in the management of infectious diseases.

METHODS

The German Society of Infectious Diseases (DGI) participates in the campaign "Klug Entscheiden" by the German Society of Internal Medicine. Committee members of the (DGI) listed potential 'Choosing Wisely items'. Topics were subjected to systematic evidence review and top ten items were selected for appropriateness. Five positive and negative recommendations were approved via individual member vote.

RESULTS

The final recommendations are: (1) Imperatively start antimicrobial treatment and remove the focus in Staphylococcus aureus bloodstream infection. (2) Critically ill patients with signs of infection need early appropriate antibiotic therapy. (3) Annual influenza vaccination should be given to individuals with age >60 years, patients with specific co-morbidities and to contact persons who may spread influenza to others. (4) All children should receive measles vaccine. (5) Prefer oral formulations of highly bioavailable antimicrobials whenever possible. (6) Avoid prescribing antibiotics for uncomplicated upper respiratory tract infections. (7) Do not treat asymptomatic bacteriuria with antibiotics. (8) Do not treat Candida detected in respiratory or gastrointestinal tract specimens. (9) Do not prolong prophylactic administration of antibiotics in patients after they have left the operating room. (10) Do not treat an elevated C-reactive protein (CRP) or procalcitonin with antibiotics for patients without signs of infection.

CONCLUSIONS

Physicians will reduce potential harm to patients and increase the value of health care when implementing these recommendations.

The Safety and Economic Impact of Cefazolin versus Nafcillin for the Treatment of Methicillin-Susceptible Staphylococcus aureus Bloodstream Infections

Introduction

Anti-staphylococcal penicillins are generally accepted as first-line therapy for methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, but their use may be limited by interstitial nephritis and acute kidney injury. Alternatives include first-generation cephalosporins including cefazolin.

Methods

We conducted a retrospective cohort study to compare adverse effects and clinical outcomes among patients with MSSA bacteremia treated with cefazolin or nafcillin. The primary endpoint was acute kidney injury (AKI), defined as a 0.3 mg/dL or 50% increase from baseline.

Results

Incidence of AKI was 27/82 (33%) versus 9/68 (13%) (p = 0.007) in the nafcillin and cefazolin arms, respectively. After adjusting for endocarditis and intensive care unit admission in multivariate logistic regression, nafcillin was an independent predictor of AKI [adj odds ratio (OR) = 2.74; 95% (CI) 1.1–6.6]. Patients who experienced AKI were more likely to have a prolonged intensive care unit stay.

Conclusion

Risk of nephrotoxicity is increased with nafcillin compared with cefazolin. Cefazolin should considered as a safer alternative to nafcillin for select patients with MSSA bacteremia.

Electronic supplementary material

The online version of this article (doi:10.1007/s40121-017-0148-z) contains supplementary material, which is available to authorized users.

Comparative Sensitivity of Transthoracic and Transesophageal Echocardiography in Diagnosis of Infective Endocarditis Among Veterans With Staphylococcus aureus Bacteremia

BACKGROUND

Echocardiography is fundamental for diagnosing infective endocarditis (IE) in patients with Staphylococcus aureus bacteremia (SAB), but whether all such patients require transesophageal echocardiography (TEE) is controversial.

METHODS

We identified SAB cases between February 2008 and April 2012. We compared sensitivity and specificity of transthoracic echocardiography (TTE) and TEE for evidence of IE, and we determined impacts of IE risk factors and TTE image quality on comparative sensitivities of TTE and TEE and their impact on clinical decision making.

RESULTS

Of 215 evaluable SAB cases, 193 (90%) had TTE and 130 (60%) had TEE. In 119 cases with both tests, IE was diagnosed in 29 (24%), for whom endocardial involvement was evident in 25 (86%) by TEE, vs only 6 (21%) by TTE (P < .001). Transesophageal echocardiography was more sensitive than TTE regardless of risk factors. Even among the 66 cases with adequate or better quality TTE images, sensitivity was only 4 of 17 (24%) for TTE, vs 16 of 17 (94%) for TEE (P < .001). Among 130 patients with TEE, the TEE results, alone or with TTE results, influenced treatment duration in 56 (43%) cases and led to valve surgery in at least 4 (6%). It is notable that, despite vigorous efforts to obtain both tests routinely, TEE was not done in 86 cases (40%) for various reasons, including pathophysiological contraindications (14%), patient refusal or other patient-related factors (16%), and provider declination or system issues (10%).

CONCLUSIONS

Patients with SAB should undergo TEE when possible to detect evidence for IE, especially if the results might affect management.

Infective endocarditis following tumor necrosis factor-α antagonist therapy for management of psoriatic erythroderma: a case report

Background

The introduction of biological agents, such as infliximab, which act against tumor necrosis factor-α was a major advance for the treatment of an increasing number of chronic diseases. Tumor necrosis factor-α antagonists represent a major therapeutic advance for the management of chronic inflammatory diseases, such as psoriasis. Previous studies have reported that the use of tumor necrosis factor-α antagonists increased the risk of opportunistic infections and reactivation of latent bacterial infections. Cardiac involvement, such as infective endocarditis, is very rare in the literature.

Case presentation

A 77-year-old Asian man with a 10-year history of psoriatic erythroderma was referred due to high fever and general malaise. He was treated with Predonine (prednisolone) and infliximab. After treatment, cardiac echography showed mitral valve vegetation and brain magnetic resonance imaging indicated multiple fresh infarctions. He died from large brain infarction in October 2013. An autopsy showed fresh thrombosis in his left middle cerebral artery, mitral valve vegetations, and septic micro-embolisms in multiple organs.

Conclusions

Lethal bacterial endocarditis was revealed after administration of tumor necrosis factor-α inhibitor, infliximab, for the treatment of psoriatic erythroderma. An autopsy showed vegetation in his mitral valve and brain infarction with fresh purulent embolism in his left middle cerebral artery and septic micro-embolisms.

Paediatric Staphylococcus aureus bacteraemia: A single-centre retrospective cohort

AIM

We aimed to describe the clinical epidemiology of Staphylococcus aureus bacteraemia (SAB) at a large, tertiary/quaternary children's hospital in Australia.

METHODS

We performed a retrospective chart review of SAB cases at the Children's Hospital at Westmead (CHW) over 5 years; 2006-2011. We compared frequency, clinical profile and outcomes of SAB with published data from CHW; 1994-1998. We compared health-care associated with community-associated (HCA-SAB and CA-SAB; defined epidemiologically) and methicillin-resistant with methicillin susceptible S. aureus (MRSA and MSSA).

RESULTS

We identified 174 episodes of paediatric SAB with an average annual admission rate of 1.3/1000 which has not increased compared with a decade earlier. Half of the cases (49%) were CA-SAB; 18% were MRSA. The proportion of CA-MRSA bacteraemia (22%) has increased. The proportion of SAB associated with central venous access devices (CVADs; 40%) has increased. CA-SAB cases were more likely to present with a tissue focus of disease (e.g. osteo-articular, pneumonia) and often required surgery. HCA-SAB less frequently required surgery, a minority is MRSA, and vascular device intervention (removal, sterilisation) is common. Six cases (4%) of infective endocarditis (IE) were identified; three with a history of congenital heart disease, two with CVADs in situ. There were no deaths in this cohort.

CONCLUSIONS

Over an 18-year period, the proportion of SAB due to CA-MRSA and SAB associated with CVADs has increased. Categorisation of SAB as HCA and CA reveals two broad phenotypes of paediatric SAB. SAB in children is infrequently associated with IE. The health-care burden of paediatric SAB is considerable', but mortality is low.

Assessment of linezolid prescriptions in three French hospitals

The use of linezolid to treat gram-positive cocci infections is increasing in France. Linezolid is approved in pneumonia and complicated skin and soft tissue infections. Overuse and misuse of linezolid can favor the emergence and spreading of linezolid-resistant strains. We aimed to assess the appropriateness of linezolid use in French hospitals. This is a multicenter, retrospective study conducted in three tertiary care hospitals. Appropriateness of linezolid indications and adequacy (composite score concerning dosage, route of administration and blood monitoring) were assessed. Over a three-month period, all prescriptions of linezolid were extracted and analyzed by two independent infectious disease experts. Among the 81 initial prescriptions that were evaluated, indication was appropriate in 48% of cases. Among those, 51% complied with international guidelines. Fifty-seven percent of the prescriptions were adequate regarding dosage, route of administration and blood monitoring. Overall, 23% of prescriptions combined both appropriateness and adequacy. The most frequent reasons for inappropriateness were the possibility of choosing narrower-spectrum antibiotics and the empirical use of linezolid in severe sepsis or septic shock. Initial treatment was the most frequently appropriate in bone and joint infection cases (p = 0.001). Our study shows that even if modalities of use were mostly correct, appropriateness of linezolid indications is low. Educational programs are mandatory to improve practices, as well as clinical studies to better assess the efficacy and safety of linezolid in clinical situations other than pneumonia or complicated skin and soft tissue infections.

Two cases of serious rhabdomyolysis during linezolid treatment

Linezolid is an oxazolidinone antibiotic with activity against gram-positive organisms, particularly methicillin-resistant Staphylococcus aureus (MRSA). To the best of our knowledge, there are only two case reports on rhabdomyolysis in patients treated with linezolid. Here, we describe two cases of serious rhabdomyolysis: one in a patient with septic community-acquired (CA)-MRSA pneumonia and a second case in a patient with suspected catheter-related blood stream infection.

Significant publications on infectious diseases pharmacotherapy in 2015

PURPOSE

The most important articles on infectious diseases (ID) pharmacotherapy published in the peer-reviewed literature in 2015, as nominated and selected by panels of pharmacists and others with ID expertise, are summarized.

SUMMARY

Members of the Houston Infectious Diseases Network were asked to nominate articles published in prominent peer-reviewed journals in 2015 that were thought to have a major impact in the field of ID pharmacotherapy. A list of 55 nominated articles on general ID-related topics and 10 articles specifically related to human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS) was compiled. In a national online survey, members of the Society of Infectious Diseases Pharmacists (SIDP) were asked to select from the list 10 general ID articles believed to have made a significant contribution to the field of ID pharmacotherapy and 1 article contributing to HIV/AIDS pharmacotherapy. Of the 361 SIDP members surveyed, 153 (42%) and 76 (21%) participated in the selection of general ID-related articles and HIV/AIDS-related articles, respectively. The 11 highest-ranked publications (10 general ID-related articles and 1 HIV/AIDS-related article) are summarized here.

CONCLUSION

With the growing number of significant ID-related publications each year, it can be challenging to stay current with the literature. This review of important ID pharmacotherapy publications in 2015 may be helpful in identifying key articles and lessening this burden.

A novel chimeric lysin with robust antibacterial activity against planktonic and biofilm methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most threatening pathogens due to its multi-drug resistance (MDR) and strong biofilm-forming capacity. Here, we described the screening of a novel chimeolysin (ClyF) that was active against planktonic and biofilm MRSA. Biochemical tests showed that ClyF was active against all S. aureus clinical isolates tested under planktonic and biofilm conditions. Structure analysis revealed that ClyF has an enhanced thermostability and pH tolerance than its parental lysin Pc by forming a hydrophobic cleft in the catalytic domain and an Ig-like structure in the cell-wall binding domain. A single intraperitoneally or topically administration of ClyF showed good MRSA removing efficacy in mouse models of bacteremia and burn wound infection, respectively. Our data collectively demonstrated that ClyF has good bactericidal activity against planktonic and biofilm MRSA both in vitro and in vivo, and therefore represents a useful antibacterial to combat MDR S. aureus.

Synergistic antibacterial effects of herbal extracts and antibiotics on methicillin-resistant Staphylococcus aureus: A computational and experimental study

Antibiotic resistance has become a serious global concern, and the discovery of antimicrobial herbal constituents may provide valuable solutions to overcome the problem. In this study, the effects of therapies combining antibiotics and four medicinal herbs on methicillin-resistant Staphylococcus aureus (MRSA) were investigated. Specifically, the synergistic effects of Magnolia officinalis, Verbena officinalis, Momordica charantia, and Daphne genkwa in combination with oxacillin or gentamicin against methicillin-resistant (ATCC43300) and methicillin-susceptible (ATCC25923) S. aureus were examined. In vitro susceptibility and synergistic testing were performed to measure the minimum inhibitory concentration and fractional inhibitory concentration (FIC) index of the antibiotics and medicinal herbs against MRSA and methicillin-susceptible S. aureus. To identify the active constituents in producing these synergistic effects, in silico molecular docking was used to investigate the binding affinities of 139 constituents of the four herbs to the two common MRSA inhibitory targets, penicillin binding proteins 2a (PBP2a) and 4 (PBP4). The physicochemical and absorption, distribution, metabolism, and excretion properties and drug safety profiles of these compounds were also analyzed. D. genkwa extract potentiated the antibacterial effects of oxacillin against MRSA, as indicated by an FIC index value of 0.375. M. officinalis and V. officinalis produced partial synergistic effects when combined with oxacillin, whereas M. charantia was found to have no beneficial effects in inhibiting MRSA. Overall, tiliroside, pinoresinol, magnatriol B, and momorcharaside B were predicted to be PBP2a or PBP4 inhibitors with good drug-like properties. This study identifies compounds that deserve further investigation with the aim of developing therapeutic agents to modulate the effect of antibiotics on MRSA. Impact statement Antibiotic resistant is a well-known threat to global health and methicillin-resistant Staphylococcus aureus is one of the most significant ones. These resistant bacteria kill thousands of people every year and therefore a new effective antimicrobial treatment is necessary. This study identified the herbs and their associated bioactive ingredients that can potential the effects of current antibiotics. These herbs have long history of human usage in China and have well-defined monograph in the Chinese Pharmacopeia. These indicate their relatively high clinical safety and may have a quicker drug development process than that of a new novel antibiotic. Based on the results of this study, the authors will perform further in vitro and animal studies, aiming to accumulate significant data for the application of clinical trial.

Treatment of Staphylococcus aureus Infections

Staphylococcus aureus, although generally identified as a commensal, is also a common cause of human bacterial infections, including of the skin and other soft tissues, bones, bloodstream, and respiratory tract. The history of S. aureus treatment is marked by the development of resistance to each new class of antistaphylococcal antimicrobial drugs, including the penicillins, sulfonamides, tetracyclines, glycopeptides, and others, complicating therapy. S. aureus isolates identified in the 1960s were sometimes resistant to methicillin, a ß-lactam antimicrobial active initially against a majority S. aureus strains. These MRSA isolates, resistant to nearly all ß-lactam antimicrobials, were first largely confined to the health care environment and the patients who attended it. However, in the mid-1990s, new strains, known as community-associated (CA-) MRSA strains, emerged. CA-MRSA organisms, compared with health care-associated (HA-) MRSA strain types, are more often susceptible to multiple classes of non ß-lactam antimicrobials. While infections caused by methicillin-susceptible S. aureus (MSSA) strains are usually treated with drugs in the ß-lactam class, such as cephalosporins, oxacillin or nafcillin, MRSA infections are treated with drugs in other antimicrobial classes. The glycopeptide drug vancomycin, and in some countries teicoplanin, is the most common drug used to treat severe MRSA infections. There are now other classes of antimicrobials available to treat staphylococcal infections, including several that have been approved after 2009. The antimicrobial management of invasive and noninvasive S. aureus infections in the ambulatory and in-patient settings is the topic of this review. Also discussed are common adverse effects of antistaphylococcal antimicrobial agents, advantages of one agent over another for specific clinical syndromes, and the use of adjunctive therapies such as surgery and intravenous immunoglobulin. We have detailed considerations in the therapy of noninvasive and invasive S. aureus infections. This is followed by sections on specific clinical infectious syndromes including skin and soft tissue infections, bacteremia, endocarditis and intravascular infections, pneumonia, osteomyelitis and vertebral discitis, epidural abscess, septic arthritis, pyomyositis, mastitis, necrotizing fasciitis, orbital infections, endophthalmitis, parotitis, staphylococcal toxinoses, urogenital infections, and central nervous system infections.

Blood cultures in the evaluation of uncomplicated cellulitis

PURPOSE

The frequency of bacteremia and the array of microorganisms involved in cellulitis vary greatly among studies. Although current guidelines do not recommend routine blood culture in uncomplicated cellulitis, their implementation in clinical practice remains challenging. We therefore aimed to assess the frequency, determinants and microbiology of bacteremia in hospitalized patients with uncomplicated cellulitis.

METHODS

We retrospectively reviewed the medical records of all adult patients admitted at a primary-care hospital with a diagnosis of community-acquired uncomplicated cellulitis during a 4-year period. We looked at the factors associated with blood cultures sampling and at the incidence, determinants and microbiology of bacteremia in this population.

RESULTS

Among the 476 patients hospitalized with a diagnosis of cellulitis, 250 (52.5%) had blood cultures. Fever, high C-reactive protein and lymphatic insufficiency were significantly associated with the sampling of blood cultures. Twelve (4.8%) patients had bacteremia. Alcoholism and duration of hospitalization were associated with bacteremia in multivariate analysis. Among the 12 patients with bacteremia, 9 had Streptococcus sp. and 3 had Staphylococcus aureus infection.

CONCLUSION

In our study population with uncomplicated cellulitis, representative of unselected population admitted at primary-care hospitals, bacteremia was uncommon and not associated with discriminant patient characteristics, except for alcohol abuse. Episodes of bacteremia were exclusively due to gram-positive cocci susceptible to co-amoxicilin, a common first-line empirical therapy. In accordance with existing guidelines, we do not recommend to collect blood for cultures in uncomplicated cellulitis. Clinicians' awareness of guidelines and of the poor yield of blood cultures could reduce useless investigation.

Ceftaroline as Salvage Monotherapy for Persistent MRSA Bacteremia

OBJECTIVE

To summarize published data regarding the use of ceftaroline as salvage monotherapy for persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia.

DATA SOURCES

PubMed (January 1980-June 2016) was searched using combinations of the search terms methicillin-resistant Staphylococcus aureus, MRSA, bacteremia, ceftaroline, refractory, and persistent Supplemental references were generated through review of identified literature citations.

STUDY SELECTION AND DATA EXTRACTION

Available English-language, full-text articles pertaining to the use of ceftaroline for persistent MRSA bacteremia (MRSAB) were included.

DATA SYNTHESIS

The PubMed search yielded 23 articles for evaluation. There are no randomized controlled trials to date-only case series and reports. Four retrospective case series detailing the use of ceftaroline as monotherapy for persistent MRSAB were included. Most patients received at least 4 days of an appropriate anti-MRSA antimicrobial prior to ceftaroline and were able to clear bacteremia within 3 days. The most common rationales for ceftaroline use were progression of disease or nonresponse to current therapy. Higher off-label dosing of ceftaroline is often utilized to achieve optimal pharmacokinetic/pharmacodynamic parameters. Adverse events are not well described due to lack of follow-up; however, neutropenia has been associated with prolonged use.

CONCLUSIONS

Treatment options for persistent MRSAB remain few and far between. Ceftaroline is an effective agent for the salvage treatment of MRSAB. Off-label doses up to 600 mg every 8 hours are often used to achieve optimal pharmacokinetic/pharmacodynamic parameters. Because of lack of follow-up in these reports, the incidence of adverse effects of prolonged use of ceftaroline is not well defined.

Inhibition of the multidrug efflux pump LmrS from Staphylococcus aureus by cumin spice Cuminum cyminum

Staphylococcus aureus is a serious causative agent of infectious disease. Multidrug-resistant strains like methicillin-resistant S. aureus compromise treatment efficacy, causing significant morbidity and mortality. Active efflux represents a major antimicrobial resistance mechanism. The proton-driven multidrug efflux pump, LmrS, actively exports structurally distinct antimicrobials. To circumvent resistance and restore clinical efficacy of antibiotics, efflux pump inhibitors are necessary, and natural edible spices like cumin are potential candidates. The mode of cumin antibacterial action and underlying mechanisms behind drug resistance inhibition, however, are unclear. We tested the hypothesis that cumin inhibits LmrS drug transport. We found that cumin inhibited bacterial growth and LmrS ethidium transport in a dosage-dependent manner. We demonstrate that cumin is antibacterial toward a multidrug-resistant host and that resistance modulation involves multidrug efflux inhibition.

Towards Development of Small Molecule Lipid II Inhibitors as Novel Antibiotics

Recently we described a novel di-benzene-pyrylium-indolene (BAS00127538) inhibitor of Lipid II. BAS00127538 (1-Methyl-2,4-diphenyl-6-((1E,3E)-3-(1,3,3-trimethylindolin-2-ylidene)prop-1-en-1-yl)pyryl-1-ium) tetrafluoroborate is the first small molecule Lipid II inhibitor and is structurally distinct from natural agents that bind Lipid II, such as vancomycin. Here, we describe the synthesis and biological evaluation of 50 new analogs of BAS00127538 designed to explore the structure-activity relationships of the scaffold. The results of this study indicate an activity map of the scaffold, identifying regions that are critical to cytotoxicity, Lipid II binding and range of anti-bacterial action. One compound, 6jc48-1, showed significantly enhanced drug-like properties compared to BAS00127538. 6jc48-1 has reduced cytotoxicity, while retaining specific Lipid II binding and activity against Enterococcus spp. in vitro and in vivo. Further, this compound showed a markedly improved pharmacokinetic profile with a half-life of over 13 hours upon intravenous and oral administration and was stable in plasma. These results suggest that scaffolds like that of 6jc48-1 can be developed into small molecule antibiotic drugs that target Lipid II.

Clinical Reasoning of Infectious Diseases Physicians Behind the Use or Nonuse of Transesophageal Echocardiography in Staphylococcus aureus Bacteremia

In this prospective cohort with Staphylococcus aureus bacteremia, transesophageal echocardiography (TEE) was performed in 24% of cases. Consulting Infectious Diseases physicians most frequently cited low suspicion for endocarditis due to rapid clearance of blood cultures and the presence of a secondary focus requiring an extended treatment duration as reasons for foregoing TEE.

Use of bacterial whole-genome sequencing to understand and improve the management of invasive Staphylococcus aureus infections

INTRODUCTION

Management of invasive Staphylococcus aureus infections is complex. Dramatic improvements in bacterial whole genome sequencing (WGS) offer new opportunities for personalising the treatment of S. aureus infections. Areas covered: We address recent achievements in S. aureus genomics, describe genetic determinants of antibiotic resistance and summarise studies that have defined molecular characteristics associated with risk and outcome of S. aureus invasive infections. Potential clinical use of WGS for resistance prediction, infection outcome stratification and management of persistent /relapsing infections is critically discussed. Expert commentary: WGS is not only providing invaluable information to track the emergence and spread of important S. aureus clones, but also allows rapid determination of resistance genotypes in the clinical environment. An evolving opportunity is to infer clinically important outcomes and optimal therapeutic approaches from widely available S. aureus genome data, with the goal of individualizing management of invasive S. aureus infections.

Combination antimicrobial therapy in patients with Staphylococcus aureus bacteraemia-a post hoc analysis in 964 prospectively evaluated patients

OBJECTIVES

The evidence for using combination antimicrobial therapy (CoRx) in Staphylococcus aureus bacteraemia (SAB) is limited. We aimed to investigate whether CoRx is associated with higher survival or lower SAB-related late complications.

METHODS

We performed a post hoc analysis of a prospective SAB cohort study. CoRx was defined as a cell wall-active antistaphylococcal agent plus either rifampicin, a fluoroquinolone, fosfomycin or an aminoglycoside. To adjust for survivor bias multivariable Cox models that included CoRx as a time-dependent covariable were calculated.

RESULTS

Of 964 evaluable patients, 512 (53%) received CoRx, most of them (301/512, 59%) rifampicin-containing CoRx. All-cause mortality after 30 and 90 days was similar for the two groups, although the patients in the CoRx group had more often endocarditis, deep-seated or disseminated infections and severe sepsis/septic shock. For the entire cohort, only age, comorbidity and severe sepsis/septic shock were associated with a higher mortality and infectious disease consultation, but not CoRx with a lower mortality. However, in the subgroup of patients with implanted foreign bodies or devices CoRx was independently associated with a lower mortality at 30 days (hazard ratio 0.6, 95% confidence interval 0.3-1.1) and at 90 days (hazard ratio 0.6, 95% confidence interval 0.4-0.9). SAB-related late complications in this subgroup occurred in 15 (10.6%) of 142 patients in the monotherapy group vs. nine (4.5%) of 202 patients in the CoRx group (p 0.03).

CONCLUSIONS

In a setting of optimized management of adult patients with SAB secured by infectious disease consultations, this observational study could not prove CoRx to be independently associated with improved survival or reduced late complications in the entire cohort. However, administration of CoRx may be associated with lower mortality and fewer SAB-related late complications in the subgroup of patients with implanted foreign bodies or devices. Prospective randomized trials should be performed to prove this benefit.

Infective endocarditis

Infective endocarditis (IE) is a rare, life-threatening disease that has long-lasting effects even among patients who survive and are cured. IE disproportionately affects those with underlying structural heart disease and is increasingly associated with health care contact, particularly in patients who have intravascular prosthetic material. In the setting of bacteraemia with a pathogenic organism, an infected vegetation may form as the end result of complex interactions between invading microorganisms and the host immune system. Once established, IE can involve almost any organ system in the body. The diagnosis of IE may be difficult to establish and a strategy that combines clinical, microbiological and echocardiography results has been codified in the modified Duke criteria. In cases of blood culture-negative IE, the diagnosis may be especially challenging, and novel microbiological and imaging techniques have been developed to establish its presence. Once diagnosed, IE is best managed by a multidisciplinary team with expertise in infectious diseases, cardiology and cardiac surgery. Antibiotic prophylaxis for the prevention of IE remains controversial. Efforts to develop a vaccine that targets common bacterial causes of IE are ongoing, but have not yet yielded a commercially available product.

Effectiveness of oral antibiotics for definitive therapy of Gram-negative bloodstream infections

There is paucity of data evaluating intravenous-to-oral antibiotic switch options for Gram-negative bloodstream infections (BSIs). This retrospective cohort study examined the effectiveness of oral antibiotics for definitive treatment of Gram-negative BSI. Patients with Gram-negative BSI hospitalised for <14 days at Palmetto Health Hospitals in Columbia, SC, from 1 January 2010 through 31 December 2013 and discharged on oral antibiotics were included in this study. The cohort was stratified into three groups based on bioavailability of oral antibiotics prescribed (high, ≥95%; moderate, 75-94%; and low, <75%). Kaplan-Meier analysis and multivariate Cox proportional hazards regression were used to examine treatment failure. Among the 362 patients, high, moderate and low bioavailability oral antibiotics were prescribed to 106, 179 and 77 patients, respectively, for definitive therapy of Gram-negative BSI. Mean patient age was 63 years, 217 (59.9%) were women and 254 (70.2%) had a urinary source of infection. Treatment failure rates were 2%, 12% and 14% in patients receiving oral antibiotics with high, moderate and low bioavailability, respectively (P = 0.02). Risk of treatment failure in the multivariate Cox model was higher in patients receiving antibiotics with moderate [adjusted hazard ratio (aHR) = 5.9, 95% CI 1.6-38.5; P = 0.005] and low bioavailability (aHR = 7.7, 95% CI 1.9-51.5; P = 0.003) compared with those receiving oral antimicrobial agents with high bioavailability. These data demonstrate the effectiveness of oral antibiotics with high bioavailability for definitive therapy of Gram-negative BSI. Risk of treatment failure increases as bioavailability of the oral regimen declines.

In vitro synergistic effects of various combinations of vancomycin and non-beta-lactams against Staphylococcus aureus with reduced susceptibility to vancomycin

The aim of our study was to determine the potential for synergistic effect of vancomycin combined with a non-beta-lactam agent and of combinations of orally available non-beta-lactam agents against vancomycin-intermediate S. aureus (VISA) and heterogeneous VISA (hVISA). Three VISA isolates, three hVISA isolates, and two vancomycin-susceptible S. aureus (VSSA) isolates were used. The combinations included vancomycin and one of clindamycin, ciprofloxacin, gentamicin, rifampicin, or trimethoprim/sulfamethoxazole. Pairwise combinations among five non-beta-lactam agents were also tested for synergy. Synergy was determined using time-kill curves at 24h. Vancomycin combined with either ciprofloxacin or gentamicin showed synergy against some isolates of VISA, hVISA and VSSA. Vancomycin combined with trimethoprim/sulfamethoxazole showed synergy against VISA and hVISA. Among orally available non-beta-lactam agents, only ciprofloxacin combined with either clindamycin or trimethoprim/sulfamethoxazole showed synergy against one isolate of VISA.

The Impact of Reporting a Prior Penicillin Allergy on the Treatment of Methicillin-Sensitive Staphylococcus aureus Bacteremia

BACKGROUND

Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection with mortality benefit from receipt of parenteral β-lactam therapy. A substantial portion of MSSA bacteremia patients report penicillin allergy, but infrequently have true allergy.

OBJECTIVE

To determine the frequency and predictors of optimal and adequate therapy in patients with MSSA bacteremia.

DESIGN

Retrospective cohort.

PARTICIPANTS

Adult inpatients with MSSA bacteremia, January 2009 through October 2013.

MAIN MEASURES

The primary measure was a trial of optimal therapy (OT), defined as ≥3 inpatient days or discharge on any first-line agents (nafcillin, oxacillin, cefazolin, or penicillin G, if susceptible). The secondary measure was completion of adequate therapy (AT), defined as ≥10 inpatient days or discharge on an agent appropriate for MSSA bacteremia. Data were electronically gathered with key variables manually validated through chart review. Log-binomial regression models were used to determine the frequency and predictors of outcomes.

KEY RESULTS

Of 456 patients, 346 (76%) received a trial of OT. Patients reporting penicillin allergy (13%) were less likely to receive OT trial than those without penicillin allergy (47% vs. 80%, p <0.001). Adjusting for other factors, penicillin allergy was the largest negative predictor of OT trial (RR 0.64 [0.49, 0.83]). Infectious Disease (ID) consultation was the largest positive predictor of OT trial across all patients (RR 1.34 [1.14, 1.57]). Allergy/Immunology consultation was the single most important predictor of OT trial among patients reporting penicillin allergy (RR 2.33 [1.44, 3.77]). Of 440 patients, 391 (89%) completed AT, with ID consultation the largest positive predictor of the outcome (RR 1.28 [1.15, 1.43]).

CONCLUSIONS

Nearly 25% of patients with MSSA bacteremia did not receive OT trial and about 10% did not receive AT completion. Reported penicillin allergy reduced, and ID consult increased, the likelihood of OT. Allergy evaluation, coupled with ID consultation, may improve outcomes in MSSA bacteremic patients.

Time trends in Staphylococcus aureus bacteremia, 1988-2010, in a tertiary center with high methicillin resistance rates

INTRODUCTION

Changes in the epidemiology of Staphylococcus aureus bacteremia (SAB) have been described in recent decades. Decreased mortality has been reported over time, mostly from countries with low methicillin resistance rates. We aimed to describe time trends in SAB in a tertiary center with high methicillin resistance rates.

METHODS

We retrospectively analyzed 1692 patients with SAB, and compared between three time periods: 1988-1994 (342 patients), 1998-2004 (597 patients) and 2005-2010 (753 patients).

RESULTS

In our cohort, 30 days mortality increased significantly with time, reaching 42.9 % during 2005-2010. The latter period was characterized by higher rates of older patients (35.1 % aged 80 years and older), with lower functional capacity (46.5 % bedridden) and higher rates of comorbidities (33.6 % renal disease, 24.8 % heart failure, 19.0 % dementia). These patients were more likely to be ventilated (18.7 %) and carry a urinary catheter at presentation (46.6 %); present with septic shock (15.9 %) and have pneumonia (20.5 %) or endocarditis (7.2 %) as source. Similar characteristics were found among patients younger than 50 years and with independent functional status. No significant increase in methicillin resistant Staph aureus (MRSA) rates or inappropriate empirical therapy was demonstrated during 2005-2010.

CONCLUSIONS

In our cohort, increased mortality in recent years in patients with SAB can be explained by baseline condition of patients. MRSA or inappropriate empiric therapy did not explain the increase in mortality. The patients afflicted with SAB changed over time. Epidemiology and outcomes of SAB vary with time and according to geographical location. External validity of studies should be taken into consideration.

Pathogenesis of Staphylococcus aureus Bloodstream Infections

Staphylococcus aureus, a Gram-positive bacterium colonizing nares, skin, and the gastrointestinal tract, frequently invades the skin, soft tissues, and bloodstreams of humans. Even with surgical and antibiotic therapy, bloodstream infections are associated with significant mortality. The secretion of coagulases, proteins that associate with and activate the host hemostatic factor prothrombin, and the bacterial surface display of agglutinins, proteins that bind polymerized fibrin, are key virulence strategies for the pathogenesis of S. aureus bloodstream infections, which culminate in the establishment of abscess lesions. Pathogen-controlled processes, involving a wide spectrum of secreted factors, are responsible for the recruitment and destruction of immune cells, transforming abscess lesions into purulent exudate, with which staphylococci disseminate to produce new infectious lesions or to infect new hosts. Research on S. aureus bloodstream infections is a frontier for the characterization of protective vaccine antigens and the development of immune therapeutics aiming to prevent disease or improve outcomes.

Effectiveness of 5-Pyrrolidone-2-carboxylic Acid and Copper Sulfate Pentahydrate Association against Drug Resistant Staphylococcus Strains

Bacterial resistance is an ongoing challenge for pharmacotherapy and pharmaceutical chemistry. Staphylococcus aureus is the bacterial species which makes it most difficult to treat skin and soft tissue infections and it is seen in thousands of hospitalization cases each year. Severe but often underrated infectious diseases, such as complicated nasal infections, are primarily caused by MRSA and S. epidermidis too. With the aim of studying new drugs with antimicrobial activity and effectiveness on drug resistant Staphylococcus strains, our attention in this study was drawn on the activity of a new association between two natural products: 5-pyrrolidone-2-carboxylic acid (PCA), naturally produced by certain Lactobacillus species, and copper sulfate pentahydrate (CS). The antimicrobial susceptibility test was conducted taking into account 12 different Staphylococcus strains, comprising 6 clinical isolates and 6 resistant strains. PCA 4%, w/w, and CS 0.002%, w/w, association in distilled water solution was found to have bactericidal activity against all tested strains. Antimicrobial kinetics highlighted that PCA 4%, w/w, and CS 0.002% association could reduce by 5 log10 viable bacterial counts of MRSA and oxacillin resistant S. epidermidis in less than 5 and 3 minutes respectively. Microscopic investigations suggest a cell wall targeting mechanism of action. Being very safe and highly tolerated, the natural product PCA and CS association proved to be a promising antimicrobial agent to treat Staphylococcus related infections.

An Approach to Improve the Negative Predictive Value and Clinical Utility of Transthoracic Echocardiography in Suspected Native Valve Infective Endocarditis

BACKGROUND

In patients with suspected native valve infective endocarditis, current guidelines recommend initial transthoracic echocardiography (TTE) followed by transesophageal echocardiography (TEE) if clinical suspicion remains. The guidelines do not account for the quality of initial TTE or other findings that may alter the study's diagnostic characteristics. This may lead to unnecessary TEE when initial TTE was sufficient to rule out vegetation.

METHODS

The objective of this study was to determine if the use of a strict definition of negative results on TTE would improve the performance characteristics of TTE sufficiently to exclude vegetation. A retrospective analysis of patients at a single institution with suspected native valve endocarditis who underwent TTE followed by TEE within 7 days between January 1, 2007, and February 28, 2014, was performed. Negative results on TTE for vegetation were defined by either the standard approach (no evidence of vegetation seen on TTE) or by applying a set of strict negative criteria incorporating other findings on TTE. Using TEE as the gold standard for the presence of vegetation, the diagnostic performance of the two transthoracic approaches was compared.

RESULTS

In total, 790 pairs of TTE and TEE were identified. With the standard approach, 661 of the transthoracic studies had negative findings (no vegetation seen), compared with 104 studies with negative findings using the strict negative approach (meeting all strict negative criteria). The sensitivity and negative predictive value of TTE for detecting vegetation were substantially improved using the strict negative approach (sensitivity, 98% [95% CI, 95%-99%] vs 43% [95% CI, 36%-51%]; negative predictive value, 97% [95% CI, 92%-99%] vs 87% [95% CI, 84%-89%]).

CONCLUSIONS

The ability of TTE to exclude vegetation in patients is excellent when strict criteria for negative results are applied. In patients at low to intermediate risk with strict negative results on TTE, follow-up TEE may be unnecessary.

Identification of Low-Level Vancomycin Resistance in Staphylococcus aureus in the Era of Informatics

Vancomycin-intermediateStaphylococcus aureus(VISA) and heteroresistant VISA (hVISA) are pathogens for which accurate antimicrobial susceptibility testing (AST) would rule out standard treatment with vancomycin. Unfortunately, AST for vancomycin is relatively slow and standard methods are unable to reliably detect VISA and hVISA. An article in this issue (C. A. Mather, B. J. Werth, S. Sivagnanam, D. J. SenGupta, and S. M. Butler-Wu, J Clin Microbiol 54:883-890, 2016, doi:http://dx.doi.org/10.1128/JCM.02428-15) describes a rapid whole-cell matrix-assisted laser desorption ionization-time of flight proxy susceptibility method that highlights current innovations and challenges with rapid AST, VISA/hVISA identification, and clinical bioinformatics.

Staphylococcus Infections in Pregnancy: Maternal and Neonatal Risks

Staphylococcus aureus is carried by up to one third of the general population; about 2% are carriers for methicillin-resistant S. aureus (MRSA). Infections caused by the antibiotic-resistant form include skin and soft tissue infections, as well as pneumonia, sepsis, and wound infections. Although the risks of hospital-associated systemic infections have decreased with attention to infection control procedures, serious obstetric illness remains a concern. This article describes the range of MRSA infection in the setting of pregnancy and discusses risks to both mother and newborn associated with active MRSA infection during pregnancy and childbirth. Methicillin-resistant S. aureus remains a risk to mothers and newborns, requiring prompt identification and appropriate management.

The Impact of Infectious Disease Specialist Consultation for Staphylococcus aureus Bloodstream Infections: A Systematic Review

Staphylococcus aureus is a common cause of severe bloodstream infection. We performed a systematic review to assess whether consultation with infectious disease specialists decreased all-cause mortality or rate of complications of S aureus bloodstream infections. The review also assessed parameters associated with the quality of management of the infection. We searched for eligible studies in PubMed, Embase, Scopus, and clinical trials.gov as well as the references of included studies. We identified 22 observational studies and 1 study protocol for a randomized trial. A meta-analysis was not performed because of the high risk of bias in the included studies. The outcomes are reported in a narrative review. Most included studies reported survival benefit, in the adjusted analysis. Recommended management strategies were carried out significantly more often among patients seen by an infectious disease specialist. Trials, such as cluster-randomized controlled trials, can more validly assess the studies at low risk of bias.

Infectious diseases consultations can make the difference: a brief review and a plea for more infectious diseases specialists in Germany

Trained infectious diseases (ID) specialists are an integral part of inpatient and outpatient care in many countries, however, these specialized services are established only in selected tertiary care hospitals in Germany. This review summarises studies that addressed the impact of ID consultation services on patient care and outcome. Extensive data for a clinical benefit is available in the context of Staphylococcus aureus bacteremia (SAB), in which in-hospital or 30-day mortality was significantly reduced by 40-50 % in patients evaluated and treated in cooperation with ID consultants. This effect was associated with improved adherence to quality-of-care standards. Moreover, newer studies show a reduced length of hospital stay due to ID consultations, especially if patients are evaluated early in the course of their hospital stay. Of note, informal consultations do not seem to be equivalent to a formal ID consultation with bedside patient evaluation. Studies in other patient groups (solid organ transplant recipients or intensive care unit patients) or in the context of other infections (infective endocarditis, pneumonia, other bloodstream infections) also revealed positive effects of ID consultations. Higher rates of appropriate empirical and targeted antimicrobial treatments and de-escalation strategies due to successful pathogen identification were documented. These modifications resulted in lower treatment costs and decreased antimicrobial resistance development. Although there are methodological limitations in single studies, we consider the consistent and reproducible positive effects of ID consultations shown in studies in different countries and health care systems as convincing evidence for improved quality-of-care and treatment outcomes in patients with infectious diseases. Thus, we strongly recommend efforts to establish significantly more ID consultation services in hospitals in Germany.

Risk factors for long-term mortality of Staphylococcus aureus bacteremia

Staphylococcus aureus bacteremia (SAB) is a fatal disease. We aimed to describe risk factors for long-term mortality with SAB. We analyzed data from a retrospectively collected database including 1,692 patients with SAB. We considered variables of infection and background conditions for the analysis of long-term survival. The Kaplan-Meier procedure was used for analysis of long-term survival. Variables significantly associated with mortality were analyzed using a Cox regression model. We included 1,692 patients in the analysis. Patients were followed for up to 22 years. Within one year, 62% of patients died and within 5 years 72% died. A total of 82% of patients aged 65 years and older died within 5 years. Independent predictors of long-term mortality were older age (Hazard ratio 1.029, 95% confidence interval 1.022-1.036), female gender (HR 1.302, 95% CI 1.118-1.517), pneumonia or primary/ unknown source of infection (HR 1.441, 95% CI 1.230-1.689), dementia (HR 1.234, 95% CI 1.004-1.516), higher Charlson score (HR 1.155, 95% CI 1.115-1.196), shock at onset (HR 1.776, 95% CI 1.430-2.207) and arrival to hospitalization from an institution (HR 1.319, 95% CI 1.095-1.563). Long-term survival of patients older than 65 years and of women with SAB is severely curtailed.

Human Infections with Staphylococcus aureus CC398

Staphylococcus aureus isolates belonging to clonal cluster 398 (CC398) have emerged over the previous decade as a risk to livestock workers. Though most of the research to date has focused on colonization with these strains, a number of infections have also been documented, ranging from mild skin infections to more serious invasive infections and even death. Here, we review existing reports of human infections with CC398 and discuss their geographic distribution, general characteristics, and implications for future research. We identified 74 publications describing CC398 infections in humans in 19 different countries, suggesting this is an emerging worldwide issue.

Inhibition of bacterial and fungal pathogens by the orphaned drug auranofin

BACKGROUND

We identified auranofin as an antimicrobial compound utilizing a high-throughput screen using a Caenorhabditis elegans-Staphylococcus aureus infection model. Results/methodology: Treatment of infected nematodes with auranofin resulted in a prolonged survival rate of 95%, reached with 0.78 μg/ml. Further investigation of the antimicrobial activity of auranofin found inhibition against S. aureus, Enterococcus faecium and Enterococcus faecalis. Importantly, the fungal pathogens Cryptococcus neoformans was also effectively inhibited with an MIC at 0.5 μg/ml. Auranofin appears to target the thioredoxin system.

CONCLUSION

This work provides extensive additional data on the antibacterial effects of auranofin that includes both reference and clinical isolates and reports a novel inhibition of fungal pathogens by this compound.

The Staphylococcus aureus Chaperone PrsA Is a New Auxiliary Factor of Oxacillin Resistance Affecting Penicillin-Binding Protein 2A

Expression of the methicillin-resistant S. aureus (MRSA) phenotype results from the expression of the extra penicillin-binding protein 2A (PBP2A), which is encoded by mecA and acquired horizontally on part of the SCCmec cassette. PBP2A can catalyze dd-transpeptidation of peptidoglycan (PG) because of its low affinity for β-lactam antibiotics and can functionally cooperate with the PBP2 transglycosylase in the biosynthesis of PG. Here, we focus upon the role of the membrane-bound PrsA foldase protein as a regulator of β-lactam resistance expression. Deletion of prsA altered oxacillin resistance in three different SCCmec backgrounds and, more importantly, caused a decrease in PBP2A membrane amounts without affecting mecA mRNA levels. The N- and C-terminal domains of PrsA were found to be critical features for PBP2A protein membrane levels and oxacillin resistance. We propose that PrsA has a role in posttranscriptional maturation of PBP2A, possibly in the export and/or folding of newly synthesized PBP2A. This additional level of control in the expression of the mecA-dependent MRSA phenotype constitutes an opportunity to expand the strategies to design anti-infective agents.

Reply to: "The Possible Role of Anti-methicillin-resistant Staphylococus Aureus Antimicrobial Agents in Spontaneous Bacterial Peritonitis"

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An educational forum to engage infectious diseases and microbiology residents in resource stewardship modelled after the Choosing Wisely campaign

BACKGROUND:

Rising costs present a major threat to the sustainability of health care delivery. Resource stewardship is increasingly becoming an expected competency of physicians. The Choosing Wisely framework was used to introduce resource stewardship at a national educational retreat for infectious disease and microbiology residents.

METHODS:

During the 2014 Annual Canadian Infectious Disease and Microbiology Resident Retreat in Toronto, Ontario, infectious disease (n=50) and microbiology (n=17) residents representing 11 Canadian universities from six provinces, were invited to participate in a modified Delphi panel. Participants were asked, in advance of the retreat, to submit up to five practices that infectious disease and microbiology specialists should not routinely perform due to lack of proven benefit(s) and/or potential harm to patients. Submissions were discussed in small and large group forums using an iterative approach involving electronic polling until consensus was reached for five practices. A finalized list was created for both educational purposes and for residents to consider enacting; however, it was not intended to replace formal society-endorsed statements. A follow-up survey at two-months was conducted.

RESULTS:

Consensus was reached by the residents regarding five low-value practices within the purview of infectious diseases and microbiology physicians. After the retreat, 20 participants (32%) completed the follow-up survey. The majority of respondents (75%) believed that the session was at least as relevant as other sessions they attended at the retreat, including 95% indicating that at least some of the material discussed was new to them. Since returning to their home institutions, nine (45%) respondents have incorporated what they learned into their daily practice; four (20%) reported that they have considered initiating a project related to the session; and one (5%) reported having initiated a project.

CONCLUSIONS:

The present educational forum demonstrated that trainees can become actively engaged in the identification and discussion of low-value practices. Embedding residence training programs with resource stewardship education will be necessary to improve the value of care offered by the future members of our profession.

Staphylococcus aureus bacteraemia associated with injected new psychoactive substances

Injecting drug use is often associated with deep-seated infection. In Lothian in Scotland there has been a recent increase in the use of injected new psychoactive substances (NPS). Patients who have injected NPS have presented with Staphylococcus aureus bacteraemia (SAB) with life-threatening complications. We describe a unique case-series of 14 episodes of SAB in ten patients. Users of injected NPS had a significantly higher incidence of endocarditis and cavitating pulmonary lesions (P < 0·05) compared to those who inject only opiates. Cases of SAB in people who inject NPS have contributed to a significant rise in the overall incidence of SAB in people who inject drugs (P < 0·05) which has in turn impacted on the ability of Lothian to meet national targets for reducing the incidence of SAB.

[Impact of an infectious diseases consultation service on the quality of care and the survival of patients with infectious diseases]

While trained infectious diseases (ID) specialists are regularly involved in inpatient and outpatient care in the United States and Canada, these specialized services are only rarely established in Germany. This article aims to summarize the findings of numerous studies that investigated the impact of ID consultation services on patient care and outcome in patients suffering from infectious diseases. The strongest evidence for a clinical benefit is found in the context of Staphylococcus aureus bacteremia (SAB), where in-hospital- and day-30 mortality was significantly and consistently reduced by about 40% in patients that were evaluated and treated in cooperation with an ID physician. Furthermore, studies revealed that this effect was associated with an improved adherence to standards of care. Newer studies show a reduced length of hospital stay due to ID consultations, especially if patients are evaluated early in the course of their hospital stay. Of note, informal or curbside consultations do not seem to be equivalent to a formal ID consultation with bedside patient evaluation. Studies in other patient groups (solid organ transplant recipients or intensive care unit patients) or in the context of other infections (infective endocarditis, pneumonia, other bloodstream infections) also revealed positive effects of ID consultations. Higher rates of appropriate empirical and targeted antimicrobial treatments and de-escalation strategies due to successful pathogen identification were documented. These modifications resulted in lower treatment costs and decreased antimicrobial resistance development. Although there are methodological limitations in single studies, we consider the consistent and reproducible positive effects of ID consultations shown in studies in different countries and health care systems as convincing evidence for the improved quality of care and treatment outcomes in patients with infectious diseases. Thus, strong consideration should be given to establish ID consultation services in small and medium sized hospitals as well.

Infectious disease consultation for Staphylococcus aureus bacteremia - A systematic review and meta-analysis

OBJECTIVE

Mortality and morbidity of Staphylococcus aureus bacteremia (SAB) still remains considerably high. We aimed to evaluate the impact of infectious disease consultation (IDC) on the management and outcomes of patients with SAB.

METHODS

We systematically searched 3 publication databases from inception to 31st May 2015 and reference lists of identified primary studies.

RESULTS

Our search returned 2874 reports, of which 18 fulfilled the inclusion criteria, accounting for 5337 patients. Overall 30-day mortality was 19.95% [95% CI 14.37-27.02] with a significant difference in favour of the IDC group (12.39% vs 26.07%) with a relative risk (RR) of 0.53 [95% CI 0.43-0.65]. 90-day mortality and relapse risk for SAB were also reduced significantly with RRs of 0.77 [95% CI 0.64-0.92] and 0.62 [95% CI 0.39-0.99], respectively. Both, the appropriateness of antistaphylococcal agent and treatment duration was improved by IDC (RR 1.14 [95% CI 1.08-1.20] and 1.85 [95% CI 1.39-2.46], respectively). Follow-up blood cultures and echocardiography were performed more frequently following IDC (RR 1.35 [95% CI 1.25-1.46] and 1.98 [95% CI 1.66-2.37], respectively).

CONCLUSIONS

Evidence-based clinical management enforced by IDC may improve outcome of patients with SAB. Well-designed cluster-randomized controlled trials are needed to confirm this finding from observational studies.

Treatment of methicillin-sensitive Staphylococcus aureus bacteremia secondary to septic phlebitis using dalbavancin

WHAT IS KNOWN AND OBJECTIVE

Treatment of bacteremia due to Staphylococcus aureus often requires prolonged therapy leading to increased hospital lengths of stay and associated costs. For certain patients, referral to an outpatient parenteral antimicrobial therapy (OPAT) programme serves as an alternative to increased inpatient length of stay. We report an alternative to OPAT using dalbavancin for the treatment of methicillin-sensitive Staphylococcus aureus (MSSA).

CASE SUMMARY

A 54-year-old Caucasian man was brought to the emergency department from a rehabilitation centre with altered mental status and possible seizure. A peripheral intravenous catheter was placed in the left forearm, and the patient was transferred to the intensive care unit (ICU) for management of his acute psychosis, possible seizure and hyponatremia. Seven days into admission, the patient became febrile thought to be secondary to septic phlebitis of the forearm. Blood cultures were taken and organism identification using Nanosphere Verigene^® BC-GP rapid diagnostic testing resulted in MSSA. The patient received treatment with cefazolin with a planned treatment duration of 14 days but because of the patient's history of alcohol abuse, psychosis requiring hospitalization via the Baker Act, and history of non-compliance to follow-up appointments, the patient was deemed ineligible for OPAT. Due to the limited treatment options, therapy for MSSA bacteremia was changed on day 6 of cefazolin therapy to dalbavancin to complete the 14-day treatment duration. Blood cultures were negative at the end of treatment and no relapse of infection occurred.

WHAT IS NEW AND CONCLUSION

To our knowledge, this is the first case report using dalbavancin in clinical practice for the treatment of MSSA bacteremia secondary to septic phlebitis. This report highlights the potential role of the newer lipoglycopeptides, such as dalbavancin, in treating patients who require long-term parenteral antimicrobial therapy and are ineligible for treatment via OPAT.