Summary of ceftaroline fosamil clinical trial studies and clinical safety

Staph wars: the antibiotic pipeline strikes back

Antibiotic chemotherapy is widely regarded as one of the most significant medical advancements in history. However, the continued misuse of antibiotics has contributed to the rapid rise of antimicrobial resistance (AMR) globally. Staphylococcus aureus, a major human pathogen, has become synonymous with multidrug resistance and is a leading antimicrobial-resistant pathogen causing significant morbidity and mortality worldwide. This review focuses on (1) the targets of current anti-staphylococcal antibiotics and the specific mechanisms that confirm resistance; (2) an in-depth analysis of recently licensed antibiotics approved for the treatment of S. aureus infections; and (3) an examination of the pre-clinical pipeline of anti-staphylococcal compounds. In addition, we examine the molecular mechanism of action of novel antimicrobials and derivatives of existing classes of antibiotics, collate data on the emergence of resistance to new compounds and provide an overview of key data from clinical trials evaluating anti-staphylococcal compounds. We present several successful cases in the development of alternative forms of existing antibiotics that have activity against multidrug-resistant S. aureus. Pre-clinical antimicrobials show promise, but more focus and funding are required to develop novel classes of compounds that can curtail the spread of and sustainably control antimicrobial-resistant S. aureus infections.

Comparing the Outcomes of Ceftaroline plus Vancomycin or Daptomycin Combination Therapy versus Vancomycin or Daptomycin Monotherapy in Adults with Methicillin-Resistant Staphylococcus aureus Bacteremia—A Meta-Analysis

Introduction: Combination therapy with daptomycin plus ceftaroline to treat methicillin-resistant Staphylococcus aureus bacteremia has been reported to reduce methicillin-resistant Staphylococcus aureus bacteremia-related mortality. The purpose of the current meta-analysis was to compare the clinical outcome of methicillin-resistant Staphylococcus aureus bacteremia in patients treated with daptomycin or vancomycin plus ceftaroline combination therapy versus daptomycin or vancomycin monotherapy. Methods: Studies were included if they directly compared the efficacy of daptomycin or vancomycin plus ceftaroline combination therapy with that of daptomycin or vancomycin monotherapy in the treatment of methicillin-resistant Staphylococcus aureus bacteremia in adult patients. Results: One randomized controlled trial and five retrospective studies were included in the meta-analysis. The combination therapy group had an in-hospital mortality, duration of bacteremia, and adverse event rate similar to those patients who had monotherapy. There was less bacteremia recurrence in the combination group. Initial combination therapy with ceftaroline for the treatment of methicillin-resistant Staphylococcus aureus bacteremia showed a trend of reducing the risk of in-hospital mortality in the current meta-analysis. Conclusions: Randomized controlled trials are needed to further study the role of initial combination therapy with daptomycin or vancomycin plus ceftaroline in the treatment of methicillin-resistant Staphylococcus aureus bacteremia.

Methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage among patients with diabetes at the Korle Bu Teaching Hospital

Aim

To investigate the epidemiology of S. aureus and MRSA nasal carriage among people with diabetes at the Korle Bu Teaching Hospital in Accra, including the prevalence, predictors of carriage, and antibiotic resistance.

Methodology

This study was cross-sectional, involving 300 diabetes patients and 106 non-diabetic individuals. Swab specimens of the nares were obtained from the participants and bacteriologically-cultured. Identification and characterization of S. aureus and MRSA were based on standard bacteriological methods; antimicrobial susceptibility testing was by the Kirby-Bauer method.

Results

The prevalence of staphylococcal carriage, the diabetes group relative to the non-diabetes group, were 31.0% and 10.4% (S. aureus), and 3.3% and 0.0% (MRSA). Presence of diabetes predisposed to S. aureus carriage, but not MRSA nor coagulase-negative staphylococci (CoNS) carriage (OR = 3.88; p < 0.0001). Colonization with CoNS was protective of S. aureus (OR = 0.039, p < 0.001) and MRSA (OR = 0.115, p = 0.043) colonization among the diabetics. The antimicrobial resistance patterns recorded among the S. aureus isolated from the diabetic individuals relative to the non-diabetics were as follows: penicillin (95% vs. 91%), tetracycline (37% vs. 27%), cotrimoxazole (30% vs. 36%), erythromycin (17% vs. 0%), norfloxacin (13% vs. 0%), clindamycin (12% vs. 0%), gentamicin (9% vs. 0%), fusidic acid (10% vs. 9%), linezolid (4% vs. 0%), and rifampicin (5% vs. 0%). The proportion of multidrug resistant S. aureus was 41% (n = 38) in the diabetes group and 0% in the non-diabetes group; this difference was statistically significant (p = 0.01).

Conclusions

The presence of diabetes predisposed the participants to S. aureus carriage by almost four folds, but not MRSA carriage. Colonization with CoNS was protective of S. aureus and MRSA carriage in the diabetes group. Finally, linezolid remains a good therapeutic agent for anti-MRSA therapy.

Comparison of Etest and broth microdilution for evaluating the susceptibility of Staphylococcus aureus and Streptococcus pneumoniae to ceftaroline and of carbapenem-resistant Enterobacterales and Pseudomonas aeruginosa to ceftazidime/avibactam

OBJECTIVES

Decreased susceptibility to ceftazidime/avibactam (CZA) and ceftaroline (CPT) has been reported during antimicrobial resistance surveillance and therapy. Conventional laboratories are unable to provide timely susceptibility testing for CZA and CPT because these antimicrobial agents are not incorporated in automated susceptibility testing systems.

METHODS

We evaluated Etest and the Sensititre broth microdilution (BMD) method for testing CZA against carbapenem-resistant Gram-negative bacilli and CPT against important Gram-positive cocci bloodstream isolates. Genotypes of carbapenemases in Enterobacterales were also determined using the Xpert® Carba-R assay.

RESULTS

Etest showed ≥90% agreement with Sensititre BMD for carbapenem-resistant Klebsiella pneumoniae (CRKP) (n = 187), carbapenem-resistant Escherichia coli (CREC) (n = 28) and Streptococcus pneumoniae (n = 35); however, the very major error rate exceeded 3%. Agreement between Etest and Sensititre BMD was <90% for carbapenem-resistant Pseudomonas aeruginosa (CRPA) (n = 81), methicillin-susceptible Staphylococcus aureus (MSSA) (n = 92) and methicillin-resistant S. aureus (MRSA) (n = 170). Both agents remained potent with a high susceptibility rate by Sensititre BMD as follows: CZA against CRKP (95.0%), CREC (89.3%) and CRPA (84.5%); and CPT against MSSA (100.0%), MRSA (95.3%) and S. pneumoniae (94.3%). CZA was active against blaKPC-carrying CRKP (98.5% susceptible), and resistance in the majority of CZA-resistant Enterobacterales isolates (6 of 10 CRKP and 2 of 3 CREC) was due to the presence of a metallo-β-lactamase gene.

CONCLUSION

Our results suggest that interpretation of susceptibility results obtained by Etest for both agents should be undertaken cautiously and remains challenging.

Ceftaroline fosamil: clinical experience after 23-month prescription in a tertiary hospital

OBJECTIVE

To determine the indications, success rate and adverse effects of ceftaroline fosamil treatment in a tertiary hospital.

METHODS

In total, 84 cases from February 2018 to December 2019 were retrospectively analysed. No exclusion criteria were applied.

RESULTS

Eighty-four patients, with a median age of 70 years, of which, 6.7% (56) were male, were treated with ceftaroline fosamil for a median of 14 days. Most indications were off-label, including 29 endocarditis (34.5%), 14 bacteraemia (16.6%), 5 Central nervous system (CNS) infections (6%) and 19 osteoarticular infections (22.6%). Staphylococcus aureus was the most frequently isolated microorganism, including 28 methicillin-sensitive S. aureus (MSSA; 33.3%) and 14 methicillin-resistant S. aureus (MRSA; 16.7%), followed by coagulase-negative Staphylococcus (23, 27.4%). The main reason for ceftaroline fosamil prescription was the failure of previous treatment (41.7% of cases). Treatment was successful in 60/84 patients (71.4%) and failed clinically or microbiologically in 14 (16.7%). Eight patients died for a reason not related to the infection and two were found to have a non-infectious condition. Twenty-two of thirty-five (62.8%) patients prescribed ceftaroline because of failure of previous treatment improved, including eight endocarditis and seven bacteraemia. Adverse effects were reported in five patients (5.9%) including neutropenia, thrombocytopenia, transaminases elevation and creatinine elevation; all except one were mild and all resolved after discontinuation of treatment.

CONCLUSIONS

Ceftaroline fosamil is a well-tolerated cephalosporine, effective against multi- resistant gram-positive and many gram-negative microorganisms. Our experience suggests that it is effective as a rescue or first-line therapy in other indications than those currently approved.

Ceftaroline Cerebrospinal Fluid Penetration in the Treatment of a Ventriculopleural Shunt Infection: A Case Report

Pharmacokinetic data regarding ceftaroline fosamil (CPT) penetration into cerebrospinal fluid (CSF) are limited to a rabbit model (15% inflamed) and adult case reports. We describe serum and CSF CPT concentrations in a 21-year-old, 34.8 kg female, medically complex patient presented with a 4-day history of fevers (Tmax 39.2°C), tachypnea, tachycardia, fatigue, and a 1-week history of pus and blood draining from the ventriculopleural (VPL) shunt. A head CT and an ultrasound of the neck revealed septated complex fluid collection surrounding the shunt. Therapy was initiated with vancomycin and ceftriaxone. Blood and CSF cultures from hospital day (HD) 1 were positive for methicillin-resistant Staphylococcus aureus with a CPT MIC of 0.5 mg/L and a vancomycin MIC range of 0.5 to 1 mg/L. On HD 3, CPT was added. On HD 7, simultaneous serum (69.4, 44, and 30.2 mg/L) and CSF (1.7, 2.3, and 2.3 mg/L) concentrations were obtained at 0.25, 1.5, and 4.75 hours from the end of an infusion. Based on these concentrations, CPT CSF penetration ratio ranged from 2.4% to 7.6%. After addition of CPT, the blood and CSF cultures remained negative on a regimen of vancomycin plus CPT. On HD 14, a new left-sided VPL shunt was placed. The patient continued on CPT for a period of 7 days after the new VPL shunt placement. This case demonstrated CPT CSF penetration in a range of 2.4% to 7.6%, approximately half of the rabbit model. This allowed for CSF concentrations at least 50% free time > 4 to 6× MIC of the dosing interval with a dosing regimen of 600 mg IV every 8 hours in a 34.8 kg chronic patient and resulted in a successful clinical outcome with no identified adverse outcomes.

Advances in nanotechnology-based strategies for the treatments of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND), is a progressive neurodegenerative disease that affects both upper and lower motor neurons, which results in loss of muscle control and eventual paralysis [1]. Currently, there are as yet unresolved challenges regarding efficient drug delivery into the central nervous system (CNS). These challenges can be attributed to multiple factors including the presence of the blood-brain barrier (BBB), blood-spinal cord barrier (BSCB), as well as the inherent characteristics of the drugs themselves (e.g. low solubility, insufficient bioavailability/bio-stability, 'off-target' effects) etc. As a result, conventional drug delivery systems may not facilitate adequate dosage of the required drugs for functional recovery in ALS patients. Nanotechnology-based strategies, however, employ engineered nanostructures that show great potential in delivering single or combined therapeutic agents to overcome the biological barriers, enhance interaction with targeted sites, improve drug bioavailability/bio-stability and achieve real-time tracking while minimizing the systemic side-effects. This review provides a concise discussion of recent advances in nanotechnology-based strategies in relation to combating specific pathophysiology relevant to ALS disease progression and investigates the future scope of using nanotechnology to develop innovative treatments for ALS patients.

The treatment of resistant staphylococcal infections

Staphylococcus aureus of the many staphylococcal species is the most common cause of both skin and soft tissue infection and severe staphylococcal infections including Staphylococcus aureus bacteremia (SAB). Many antibiotics are active against the staphylococci, yet over the last 40 years antibiotic resistance, particularly resistance to beta-lactam antibiotics, has plagued antimicrobial therapy. The term “methicillin resistance” is a historic term and now refers to the ability of staphylococci, in particular methicillin-resistant Staphylococcus aureus (MRSA), to resist the action of beta-lactam antibiotics. This resistance is encoded by the mecA gene carried in a complex genetic cassette, SCC mec. Vancomycin and old antibiotics remain the keystone of treatment for resistant staphylococci. Other newer agents, and some older agents, show good activity against resistant staphylococci which are the focus of this review: trimethoprim-sulfamethoxazole, ceftaroline, daptomycin, fosfomycin, linezolid, dalbavancin, televancin, and omadacycline. Other agents with novel mechanisms of action are under development, for use as single anti-staphylococcal agents or for combination use to augment the action of the primary anti-staphylococcal agent. Vancomycin therapy carries specific risks, particularly renal dysfunction, but despite its foibles, vancomycin remains the standard of care for the treatment of resistant staphylococcal infections. Some clinicians implement an early switch from vancomycin at the earliest signs of renal dysfunction. The near horizon holds promise also of augmentation of both cellular and humoral responses to staphylococcal infection. Pending newer clinical trials that show clear superiority of one anti-staphylococcal agent over another or over vancomycin, it will remain to expert clinical judgment in determining antibiotic choice and duration of anti-staphylococcal therapy.

A Multicenter Study To Evaluate Ceftaroline Breakpoints: Performance in an Area with High Prevalence of Methicillin-Resistant Staphylococcus aureus Sequence Type 5 Lineage

Ceftaroline (CPT) is a broad-spectrum agent with potent activity against methicillin-resistant Staphylococcus aureus (MRSA). The sequence type 5 (ST5) Chilean-Cordobés clone, associated with CPT nonsusceptibility, is dominant in Chile, a region with high rates of MRSA infections. Here, we assessed the in vitro activity of CPT against a collection of MRSA isolates collected between 1999 and 2018 from nine hospitals (n = 320) and community settings (n = 41) in Santiago, Chile, and evaluated performance across testing methodologies. We found that our hospital-associated isolates exhibited higher CPT MIC distributions (MIC50 and MIC90 of 2 mg/liter) than the community isolates (MIC50 and MIC90 of 0.5 mg/liter), a finding that was consistent across time and independent of the culture source. High proportions (64%) of isolates were CPT nonsusceptible despite the absence of CPT use in Chile. Across methodologies, the Etest underestimated the MIC relative to the gold standard broth microdilution (BMD) test (MIC50 and MIC90 of 1 and 1.5 mg/liter, respectively). There was low (∼51%) categorical agreement (CA) between Etest and BMD results across CLSI and EUCAST breakpoints. The recent revision of CLSI guidelines abolished "very major error" (VME) from the previous guidelines (81%), which perform similarly to the EUCAST guidelines. The level of concordance between CLSI and EUCAST for BMD testing and Etest was >95%. Disk diffusion performed poorly relative to BMD under CLSI (CA, 55%) and EUCAST (CA, 36%) guidelines. Comparison of EUCAST to CLSI for disk diffusion (with EUCAST used as the reference) showed low agreement (CA, 25%; VME, 70%). In summary, CPT-nonsusceptible MRSA are dominant in clinical settings in Chile. Our results provide data to support the reevaluation of CPT breakpoints and to improve agreement across methodologies and agencies.

Neurological and Psychiatric Adverse Effects of Antimicrobials

Antimicrobials are a widely used class of medications, but several of them are associated with neurological and psychiatric side effects. The exact incidence of neurotoxicity with anti-infectives is unknown, although it is estimated to be < 1%. Neurotoxicity occurs with all classes of antimicrobials, such as antibiotics, antimycobacterials, antivirals, antifungals and antiretrovirals, with side effects ranging from headaches, anxiety and depression to confusion, delirium, psychosis, mania and seizures, among others. It is important to consider these possible side effects to prevent misdiagnosis or delayed treatment as drug withdrawal can be associated with reversibility in most cases. This article highlights the different neurotoxic effects of a range of antimicrobials, discusses proposed mechanisms of onset and offers general management recommendations. The effects of antibiotics on the gut microbiome and how they may ultimately affect cognition is also briefly examined.

Heterologous Machine Learning for the Identification of Antimicrobial Activity in Human-Targeted Drugs

The emergence of microbes resistant to common antibiotics represent a current treat to human health. It has been recently recognized that non-antibiotic labeled drugs may promote antibiotic-resistance mechanisms in the human microbiome by presenting a secondary antibiotic activity; hence, the development of computer-assisted procedures to identify antibiotic activity in human-targeted compounds may assist in preventing the emergence of resistant microbes. In this regard, it is worth noting that while most antibiotics used to treat human infectious diseases are non-peptidic compounds, most known antimicrobials nowadays are peptides, therefore all computer-based models aimed to predict antimicrobials either use small datasets of non-peptidic compounds rendering predictions with poor reliability or they predict antimicrobial peptides that are not currently used in humans. Here we report a machine-learning-based approach trained to identify gut antimicrobial compounds; a unique aspect of our model is the use of heterologous training sets, in which peptide and non-peptide antimicrobial compounds were used to increase the size of the training data set. Our results show that combining peptide and non-peptide antimicrobial compounds rendered the best classification of gut antimicrobial compounds. Furthermore, this classification model was tested on the latest human-approved drugs expecting to identify antibiotics with broad-spectrum activity and our results show that the model rendered predictions consistent with current knowledge about broad-spectrum antibiotics. Therefore, heterologous machine learning rendered an efficient computational approach to classify antimicrobial compounds.

A Mini-Review on Ceftaroline in Bacteremia Patients with Methicillin-Resistant Staphylococcus aureus (MRSA) Infections

OBJECTIVE

The objective of this review is to describe the outcomes of patients treated with ceftaroline in the non-Food and Drug Administration (FDA) approved indication of methicillin-resistant Staphylococcus aureus (MRSA) infections in both pediatric and adult populations.

DATA SOURCES

A systematic overview was conducted by searching PubMed, Medline, and The Cochrane Library up to January 2019.

STUDY SELECTION AND DATA EXTRACTION

All English-language clinical trials and case reports related to the efficacy of ceftaroline in new, not-yet-approved FDA indications in MRSA infections in pediatric or adult populations.

DATA SYNTHESIS

In the case of MRSA bacteremia (MRSAB) infections, three different randomized studies in pediatric patients showed effectiveness of ceftaroline. When used in the case of adult populations with MRSA bacteremia, a small trial of 16 patients showed 50% clinical success in patients with acute bacterial skin and skin structure infections versus 63% clinical success in patients with community-acquired bacterial pneumonia. Another case series of six refractory case reports showed 50% clinical success of ceftaroline in patients with MRSA.

CONCLUSIONS

Although there are few case reports and limited data to date, ceftaroline fosamil should continue to be studied as an alternative therapy in MRSA infections in both pediatric and adult populations. Clinical success rates of ceftaroline were, in most cases, considered high when treating patients with MRSA infection. More clinical trials need to be studied. In the specific case of MRSA bacteremia, the treatment options remain few and ceftaroline should be extensively studied for the salvage treatment of MRSAB.

Oxygenator Impact on Ceftaroline in Extracorporeal Membrane Oxygenation Circuits

OBJECTIVES

To determine the oxygenator impact on alterations of ceftaroline in a contemporary neonatal/pediatric (1/4-inch) and adolescent/adult (3/8-inch) extracorporeal membrane oxygenation circuit including the Quadrox-i oxygenator (Maquet, Wayne, NJ).

DESIGN

Quarter-inch and 3/8-inch, simulated closed-loop extracorporeal membrane oxygenation circuits were prepared with a Quadrox-i pediatric and Quadrox-i adult oxygenator and blood primed. Additionally, 1/4-inch and 3/8-inch circuits were also prepared without an oxygenator in series. An one-time dose of ceftaroline was administered into the circuits, and serial pre- and postoxygenator concentrations were obtained at 5 minutes, 1-, 2-, 3-, 4-, 5-, 6-, and 24-hour time points. Ceftaroline was also maintained in a glass vial, and samples were taken from the vial at the same time periods for control purposes to assess for spontaneous drug degradation.

SETTING

A free-standing extracorporeal membrane oxygenation circuit.

PATIENTS

None.

INTERVENTION

Single dose administration of ceftaroline into closed-loop extracorporeal membrane oxygenation circuits prepared with and without an oxygenator in series with serial preoxygenator, postoxygenator, and reference samples obtained for concentration determination over a 24-hour study period.

MEASUREMENTS AND MAIN RESULTS

For the 1/4-inch circuit with an oxygenator, there was 79.8% drug loss preoxygenator and 82.5% drug loss postoxygenator at 24 hours. There was a statistically significant difference (p < 0.01) in the amount of ceftaroline remaining at 24 hours when compared with each prior time point for the 1/4-inch circuit. For the 1/4-inch circuit without an oxygenator, there was no significant drug loss at any study time point. For the 3/8-inch circuit with an oxygenator, there was 76.2% drug loss preoxygenator and 77.6% drug loss postoxygenator at 24 hours. There was a statistically significant difference (p < 0.01) in the amount of ceftaroline remaining at 24 hours when compared with each prior time point for the 3/8-inch circuit. For the 3/8-inch circuit without an oxygenator, there was no significant drug loss at any study time point. The reference ceftaroline concentrations remained relatively constant during the entire study period demonstrating the ceftaroline loss in each size of the extracorporeal membrane oxygenation circuit with or without an oxygenator was not a result of spontaneous drug degradation and primarily the result of the oxygenator.

CONCLUSIONS

This ex vivo investigation demonstrated significant ceftaroline loss within an extracorporeal membrane oxygenation circuit with an oxygenator in series with both sizes of the Quadrox-i oxygenator at 24 hours. Therapeutic concentrations of ceftaroline in the setting of extracorporeal membrane oxygenation may not be achieved with current U.S. Food and Drug Administration-recommended doses, and further evaluation is needed before specific drug dosing recommendations can be made for clinical application with extracorporeal membrane oxygenation.

Efficacy and effectiveness of Ceftaroline Fosamil in patients with pneumonia: a systematic review and meta-analysis

BACKGROUND

Pneumonia is a relevant clinical and public health issue worldwide frequently associated with infections caused by Multi-Drug Resistant (MDR) pathogens. Ceftaroline fosamil is a promising new antibiotics with broad-spectrum bacterial activity. The aim of this systematic review and meta-analysis is to assess the efficacy and the effectiveness of ceftaroline fosamil in community-acquired (CAP), hospital-acquired (HAP), healthcare-associated (HCAP) and ventilator-associated (VAP) pneumonia.

METHODS

A systematic review and meta-analysis was carried out retrieving both experimental and observational studies.

RESULTS

A total of 2364 records was found and 14 manuscripts were finally considered eligible. The pooled efficacy/effectiveness was 81.2% (I2: 1.2%) in all types of pneumonia. The pooled relative risk of clinical cure was 1.1 (I2: 0.0%). The success rate was higher than 70% for infections caused by S. pneumoniae and S. aureus, including MDR pathogens.

CONCLUSIONS

Ceftaroline fosamil showed a high efficacy/effectiveness in patients with any type of pneumonia with a good safety profile.

Benzylpenicillin versus wide-spectrum beta-lactam antibiotics as empirical treatment of Haemophilus influenzae-associated lower respiratory tract infections in adults; a retrospective propensity score-matched study

There is consensus that definitive therapy for infections with H. influenzae should include antimicrobial agents with clinical breakpoints against the bacterium. In Scandinavia, benzylpenicillin is the recommended empirical treatment for community-acquired pneumonia (CAP) except in very severe cases. However, the effect of benzylpenicillin on H. influenzae infections has been debated. The aim of this study was to compare the outcomes of patients given benzylpenicillin with patients given wide-spectrum beta-lactams (WSBL) as empirical treatment of lower respiratory tract H. influenzae infections requiring hospital care. We identified 481 adults hospitalized with lower respiratory tract infection by H. influenzae, bacteremic and non-bacteremic. Overall, 30-day mortality was 9% (42/481). Thirty-day mortality, 30-day readmission rates, and early clinical response rates were compared in patients receiving benzylpenicillin (n = 199) and a WSBL (n = 213) as empirical monotherapy. After adjusting for potential confounders, empirical benzylpenicillin treatment was not associated with higher 30-day mortality neither in a multivariate logistic regression (aOR 2.03 for WSBL compared to benzylpenicillin, 95% CI 0.91–4.50, p = 0.082), nor in a propensity score-matched analysis (aOR 2.14, 95% CI 0.93–4.92, p = 0.075). Readmission rates did not significantly differ between the study groups, but early clinical response rates were significantly higher in the WSBL group (aOR 2.28, 95% CI 1.21–4.31, p = 0.011), albeit still high in both groups (84 vs 81%). In conclusion, despite early clinical response rates being slightly lower for benzylpenicillin compared to WSBL, we found no support for increased mortality or readmission rates in patients empirically treated with benzylpenicillin for lower respiratory tract infections by H. influenzae.

Ceftaroline for Suspected or Confirmed Invasive Methicillin-Resistant Staphylococcus aureus: A Pharmacokinetic Case Series

OBJECTIVES

To describe the ceftaroline pharmacokinetics in critically ill children treated for suspected or confirmed methicillin-resistant Staphylococcus aureus infections, including blood stream infection and describe the microbiological and clinical outcomes.

DESIGN

Retrospective electronic medical record review.

SETTINGS

Free-standing tertiary/quaternary pediatric children's hospital.

PATIENTS

Critically ill children receiving ceftaroline monotherapy or combination therapy for suspected or confirmed methicillin-resistant S. aureus infections in the PICU.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Seven patients, three females (43%), and four males (57%), accounted for 33 ceftaroline samples for therapeutic drug management. A median of four samples for therapeutic drug management was collected per patient (range, 2-9 samples). The median age was 7 years (range, 1-13 yr) with a median weight of 25.5 kg (range, 12.6-40.1 kg). Six of seven patients (86%) demonstrated an increase in volume of distribution, five of seven patients (71%) demonstrated an increase in clearance, and 100% of patients demonstrated a shorter half-life estimate as compared with the package insert estimate. Six of seven patients (85.7%) had documented methicillin-resistant S. aureus growth from a normally sterile site with five of six (83.3%) having documented BSI, allowing six total patients to be evaluated for the secondary objective of microbiological and clinical response. All six patients achieved a positive microbiological and clinical response for a response rate of 100%.

CONCLUSIONS

These data suggest the pharmacokinetics of ceftaroline in PICU patients is different than healthy pediatric and adult patients, most notably a faster clearance and larger volume of distribution. A higher mg/kg dose and a more frequent dosing interval for ceftaroline may be needed in PICU patients to provide appropriate pharmacodynamic exposures. Larger pharmacokinetic, pharmacodynamic, and interventional treatment trials in the PICU population are warranted.

Ceftaroline for the treatment of osteomyelitis caused by methicillin-resistant Staphylococcus aureus: a case series

Despite limited clinical data, ceftaroline is commonly used for treatment of complicated, invasive infections caused by methicillin-resistant Staphylococcus aureus (MRSA). A retrospective chart review was conducted of adult patients receiving ceftaroline for MRSA osteomyelitis admitted between April 2011 and March 2016 at a five-hospital system. Twelve patients met the inclusion criteria. All patients received prior antimicrobial therapy with a median time to switch to ceftaroline of 45.5 days. Five of the 12 patients (41.7%) met criteria for ceftaroline failure. Patients with vertebral osteomyelitis (58%) had a longer length of stay, longer ceftaroline treatment, but similar success rates to those with non-vertebral osteomyelitis (57% vs. 60%). Ceftaroline is a viable alternative for a challenging patient population that has failed or are unable to receive other therapies.

Pharmacokinetics of single-dose ceftaroline fosamil in children with cystic fibrosis

BACKGROUND

Single-dose pharmacokinetics (PK) and safety of ceftaroline fosamil with population pharmacokinetic/pharmacodynamic (PK/PD) modeling for staphylococcal pneumonia was performed in children with CF.

METHODS

Subjects between 6 and 18 years old were evaluated in this phase 1, open-label, single-dose, prospective study using 10 mg/kg (up to 600 mg). Non-compartmental analysis and population-based PK analyses with Monte Carlo simulation (for doses 8-20 mg/kg every 8 h, infused over 1-4 h) were conducted.

RESULTS

A total of 20 subjects were enrolled. The median age and weight were 12 yr (range 6.3-17.4) and 38.7 kg (range 17.8-94.3), respectively. A 3-compartment linear model incorporating age and weight provided the best fit for the data. Comparing children 6 to <12 years to those 12 to <18 years, the mean posthoc Bayesian parameter estimates for total volume of distribution (VT ) were 0.32 ± 0.05 L/kg versus 0.32 ± 0.04 L/kg, P = 0.7; and total Clearance (CLT ), 0.50 ± 0.10 L/h/kg versus 0.30 ± 0.07 L/h/kg, P = 0.001. Using susceptibility data from pediatric MRSA lower respiratory tract isolates, 8 mg/kg (maximum of 1000 mg per dose) infused over 1 h every 8 h achieved free-drug plasma concentrations above the minimum inhibitory concentration for ≥60% of the dosing interval in at least 95% of virtual subjects.

CONCLUSIONS

Since children with CF have increased ceftaroline CL compared with published data from non-CF children; greater dosages may be required in children with CF to achieve adequate exposure in the treatment of MRSA pneumonia. Pharmacodynamic-based dosing predicts that dosing should also be based on the patient's MRSA MIC.

Trimethoprim/sulfamethoxazole versus vancomycin in the treatment of healthcare/ventilator-associated MRSA pneumonia: a case-control study

Objectives

Therapeutic options available to treat MRSA pneumonia are limited. Trimethoprim/sulfamethoxazole is an attractive treatment because of its bactericidal anti-MRSA activity, oral and parenteral formulations and good penetration to the lung tissue. We aimed to compare the efficacy and safety of trimethoprim/sulfamethoxazole with vancomycin in the treatment of healthcare/ventilator-associated MRSA pneumonia.

Methods

We carried out a retrospective case-control study of all consecutive hospitalized adult patients diagnosed with MRSA pneumonia at Beilinson Hospital during 2010-15 and treated with either vancomycin or trimethoprim/sulfamethoxazole. The primary outcomes were all-cause mortality at 30 days and clinical failure at the end of treatment. In order to reduce bias affecting the decision to use a specific antibiotic and as a sensitivity analysis, a propensity-score model for choosing between vancomycin and trimethoprim/sulfamethoxazole was used.

Results

We identified 42 patients with MRSA pneumonia treated with trimethoprim/sulfamethoxazole and 39 treated with vancomycin. There were no significant differences in the baseline characteristics between the groups. Vancomycin-treated patients showed significantly higher 30 day mortality on both multivariate analysis (HR = 5.28; 95% CI = 1.50-18.60; P  < 0.05) and sensitivity analysis with propensity score [vancomycin 13/24 (54.1%) versus trimethoprim/sulfamethoxazole 4/24 (16.7%); P  < 0.05], and higher clinical failure rates [vancomycin 23/39 (59%) versus trimethoprim/sulfamethoxazole 15/42 (35.7%); P  < 0.05], also in the sensitivity analysis with propensity score [vancomycin 14/24 (58.3%) versus trimethoprim/sulfamethoxazole 6/24 (25%); P  < 0.05]. The rates of side effects in both arms were comparable.

Conclusions

Trimethoprim/sulfamethoxazole appears to be superior to vancomycin in the treatment of MRSA pneumonia. A large-scale randomized controlled trial is needed to evaluate these findings.

Combination Therapy With Vancomycin and Ceftaroline for Refractory Methicillin-resistant Staphylococcus aureus Bacteremia: A Case Series

PURPOSE

Although vancomycin has been the mainstay of therapy for methicillin-resistant Staphylococcus aureus (MRSA) infections, its effectiveness has been challenged. Combination therapy may be used for patients with persistent MRSA bacteremia refractory to initial therapy. Studies have reported in vitro synergy between vancomycin and ceftaroline; however, clinical experience with this therapy is limited. Here, we report our experience with 5 cases of vancomycin-refractory MRSA bacteremia treated with the combination of vancomycin and ceftaroline.

METHODS

Between January 2014 and August 2016, 5 patients were identified who received vancomycin and ceftaroline combination therapy due to persistent bacteremia or deterioration of their clinical status on vancomycin alone (despite a vancomycin MIC within the susceptible range).

FINDINGS

Five patients presented with MRSA bacteremia secondary to endocarditis (n = 2), epidural abscess (n = 2), or left iliopsoas abscess (n = 1). Four of the 5 patients experienced microbiologic cure, and 1 patient transitioned to palliative care.

IMPLICATIONS

This case series serves to describe additional clinical experience with vancomycin and ceftaroline combination therapy. This combination may be considered when vancomycin monotherapy does not lead to microbiological and/or clinical improvement in patients with metastatic MRSA bacteremia. Additional studies are warranted to further define its role in salvage therapy for persistent MRSA bacteremia.

Ceftaroline Fosamil: A Review in Complicated Skin and Soft Tissue Infections and Community-Acquired Pneumonia

Intravenous ceftaroline fosamil (Zinforo™), a prodrug that is rapidly converted to its active metabolite ceftaroline, is approved for use in adults and children (from 2 months of age) with complicated skin and soft tissue infections (cSSTIs) or community-acquired pneumonia (CAP). In several multinational trials, ceftaroline fosamil was an effective and generally well tolerated treatment in adult and paediatric patients with cSSTIs or CAP. In the phase 3 CANVAS trials, ceftaroline fosamil treatment was noninferior to vancomycin plus aztreonam in adults with cSSTIs. Based on a meta-analysis of three similarly designed, phase 3 trials (FOCUS 1, FOCUS 2 and an Asian trial), ceftaroline fosamil treatment was superior to ceftriaxone in adults with CAP of Pneumonia Outcomes Research Teams (PORT) risk class III or IV. Ceftaroline fosamil was also associated with high clinical cure rates in hospitalized children (aged 2 months to 17 years) with cSSTIs or CAP. With its broad spectrum of in vitro activity against clinically relevant Gram-positive [including methicillin-resistant Staphylococcus aureus (MRSA) and drug-resistant Streptococcus pneumoniae isolates] and Gram-negative pathogens implicated in cSSTIs and CAP, ceftaroline fosamil is an important treatment option for cSSTI and CAP in adults and children from the age of 2 months.

Adverse Drug Reactions Associated with Ceftaroline Use: A 2-Center Retrospective Cohort

BACKGROUND

Ceftaroline fosamil is a cephalosporin approved for treating skin and soft tissue infections (SSTIs), including those caused by methicillin-resistant Staphylococcus aureus and community-acquired pneumonia (CAP).

OBJECTIVES

We aimed to study ceftaroline use and associated adverse drug reactions (ADRs), including hypersensitivity reactions (HSRs), among inpatients.

METHODS

We performed a retrospective electronic health record review of inpatients from Massachusetts General Hospital and Brigham and Women's Hospital who received ceftaroline between May 2012 and February 2015. ADRs diagnosed by clinical providers during the course of clinical care were subsequently verified and classified. Risk factors for ADRs were identified.

RESULTS

Among 96 patients (median age, 57 years; 54% females) who received a median of 28 (interquartile range, 6-63) ceftaroline doses, 54% were being treated for methicillin-resistant Staphylococcus aureus and treatment indications other than SSTI and CAP comprised 59% of care. There were 31 ADRs observed in 20 (21%) patients; hematologic (n = 15) and cutaneous (n = 9) findings were most common. Observed HSRs included rash with mucosal lesions (n = 1), rash with skin desquamation (n = 1), and possible organ-specific HSRs (n = 2). Patients who suffered an ADR received more doses of ceftaroline (median, 46 vs 21; P = .013). There was no increased risk of ceftaroline ADR among patients with reported beta-lactam allergy history (P > .5).

CONCLUSIONS

Ceftaroline is used to treat a range of infections beyond SSTI and CAP. We observed a high rate of ADRs from ceftaroline, including signs of severe HSRs. More data are needed to understand the frequency and predictors of ceftaroline ADRs and HSRs.

PBP 4 Mediates High-Level Resistance to New-Generation Cephalosporins in Staphylococcus aureus

Staphylococcus aureus is an important cause of both hospital- and community-associated methicillin-resistant S. aureus (MRSA) infections worldwide. β-Lactam antibiotics are the drugs of choice to treat S. aureus infections, but resistance to these and other antibiotics make treatment problematic. High-level β-lactam resistance of S. aureus has always been attributed to the horizontally acquired penicillin binding protein 2a (PBP 2a) encoded by the mecA gene. Here, we show that S. aureus can also express high-level resistance to β-lactams, including new-generation broad-spectrum cephalosporins that are active against methicillin-resistant strains, through an uncanonical core genome-encoded penicillin binding protein, PBP 4, a nonessential enzyme previously considered not to be important for staphylococcal β-lactam resistance. Our results show that PBP 4 can mediate high-level resistance to β-lactams.

Ceftaroline fosamil as first-line versus second-line treatment for acute bacterial skin and skin structure infections (ABSSSI) or community-acquired bacterial pneumonia (CABP)

The Clinical Assessment Program and Teflaro(®) Utilization Registry (CAPTURE) is a multicenter registry study of acute bacterial skin and skin structure infection (ABSSSI) and community-acquired bacterial pneumonia (CABP) patients treated with ceftaroline fosamil in the US. Data for this analysis were collected between August 2011 and February 2013 at US study centres by randomly ordered chart review. Clinical success rates among ABSSSI patients were >81% when ceftaroline fosamil was used as first- or second-line therapy, including monotherapy and concurrent therapy. Among CABP patients, clinical success rates were >77% among first-line and second-line patients and patients who received first-line concurrent therapy or second line monotherapy or concurrent therapy. For CABP patients treated with ceftaroline fosamil as first-line monotherapy, the clinical success rate was 70%. Ceftaroline fosamil is an effective treatment option for patients with ABSSSI or CABP with similar clinical success rates when used as first-line or second-line treatment.

Community-acquired Haemophilus influenzae pneumonia--New insights from the CAPNETZ study

OBJECTIVES

We aimed to identify clinical characteristics and to assess effectiveness of different initial antibiotic regimens in adult patients with community-acquired pneumonia (CAP) caused by Haemophilus influenzae.

METHODS

Characteristics were compared between patients with H. influenzae monoinfection versus CAP of other and unknown aetiology enrolled by the German prospective cohort study CAPNETZ. Impact of initial antibiotic treatment on "early clinical response" according to FDA criteria and overall clinical cure were analysed.

RESULTS

H. influenzae was found in 176 out of 2790 patients with pathogen detection (6.3%). Characteristics significantly associated with a H. influenzae CAP (p < 0.017) included purulent sputum, prior pneumococcal vaccination and respiratory co-morbidities. Early clinical response rates on day 4 did not differ between patients receiving any mono- versus combination therapy (85.9% versus 88%), but were numerically higher for regimens including any fluoroquinolone (96.7%) and lower under macrolide monotherapy (70%). Initial CURB-65 score and chronic liver disease were identified as negative predictors for "early clinical response". At day 14, overall clinical cure was 91.9%.

CONCLUSIONS

H. influenzae was a common CAP pathogen, particularly in patients with previous pneumococcal vaccination and respiratory co-morbidities. Severity of illness and chronic liver disease were associated with a lower rate of "early clinical response".

In vitro activity of ceftaroline against staphylococci from prosthetic joint infection

We tested the in vitro activity of ceftaroline by Etest against staphylococci recovered from patients with prosthetic joint infection, including 97 Staphylococcus aureus isolates (36%, oxacillin resistant) and 74 Staphylococcus epidermidis isolates (74%, oxacillin resistant). Ceftaroline inhibited all staphylococci at ≤0.5 μg/mL. The ceftaroline MIC(90/50) values for methicillin-susceptible S. aureus, methicillin-susceptible S. epidermidis, methicillin-resistant S. aureus, and methicillin-resistant S. epidermidis were 0.19/0.125, 0.094/0.047, 0.5/0.38, and 0.38/0.19 μg/mL, respectively. Based on these in vitro findings, ceftaroline should be further evaluated as a potential therapeutic option for the treatment of prosthetic joint infection caused by methicillin-susceptible and methicillin-resistant S. aureus and S. epidermidis.

Ceftaroline Fosamil Use in 2 Pediatric Patients With Invasive Methicillin-Resistant Staphylococcus aureus Infections

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is one of the most common pathogens causing pediatric infections including skin and soft tissue infections, pyogenic arthritis, osteomyelitis, and septic shock. For decades, patients were treated with antibiotics such as vancomycin and clindamycin, but there is an increasing incidence of resistance to these traditional therapies. We describe 2 cases of patients with CA-MRSA invasive infections with bacteremia who experienced vancomycin therapy failure but who were successfully treated with ceftaroline fosamil. Case 1 involves an 8-year-old Hispanic male who was diagnosed with CA-MRSA bacteremia, thigh abscess, and osteomyelitis. The patient was admitted to the pediatric intensive care unit in septic shock. Case 2 involves an 8-year-old Caucasian male who was diagnosed with CA-MRSA sepsis, right arm abscess, and osteomyelitis. We were able to successfully treat both patients with CA-MRSA sepsis and invasive infection-who failed vancomycin therapy-with ceftaroline fosamil with no adverse efiects. Despite the positive outcome in both pediatric patients, clinical trials with ceftaroline fosamil are needed to further support its use in pediatric patients.

In Vitro Activity of Ceftaroline against Staphylococcus aureus Isolated in 2012 from Asia-Pacific Countries as Part of the AWARE Surveillance Program

Ceftaroline, the active metabolite of the prodrug ceftaroline-fosamil, is an advanced-generation cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA). This investigation provides in vitro susceptibility data for ceftaroline against 1,971 S. aureus isolates collected in 2012 from seven countries (26 centers) in the Asia-Pacific region as part of the Assessing Worldwide Antimicrobial Resistance and Evaluation (AWARE) program. Broth microdilution as recommended by the CLSI was used to determine susceptibility. In all, 62% of the isolates studied were MRSA, and the ceftaroline MIC90 for all S. aureus isolates was 2 μg/ml (interpretive criteria: susceptible, ≤1 μg/ml). The overall ceftaroline susceptibility rate for S. aureus was 86.9%, with 100% of methicillin-sensitive S. aureus isolates and 78.8% of MRSA isolates susceptible to this agent. The highest percentages of ceftaroline-nonsusceptible MRSA isolates came from China (47.6%), all of which showed intermediate susceptibility, and Thailand (37.1%), where over half (52.8%) of isolates were resistant to ceftaroline (MIC, 4 μg/ml). Thirty-eight ceftaroline-nonsusceptible isolates (MIC values of 2 to 4 μg/ml) were selected for molecular characterization. Among the isolates analyzed, sequence type 5 (ST-5) was the most common sequence type encountered; however, all isolates analyzed from Thailand were ST-228. Penicillin-binding protein 2a (PBP2a) substitution patterns varied by country, but all isolates from Thailand had the Glu239Lys substitution, and 12 of these also carried an additional Glu447Lys substitution. Ceftaroline-fosamil is a useful addition to the antimicrobial agents that can be used to treat S. aureus infections. However, with the capability of this species to develop resistance to new agents, it is important to recognize and monitor regional differences in trends as they emerge.

Efficacy and Safety of AFN-1252, the First Staphylococcus-Specific Antibacterial Agent, in the Treatment of Acute Bacterial Skin and Skin Structure Infections, Including Those in Patients with Significant Comorbidities

This open-label noncontrolled, phase II multicenter trial was designed to evaluate the safety, tolerability, and efficacy of 200 mg of AFN-1252, a selective inhibitor of Staphylococcus aureus enoyl-acyl carrier protein reductase (FabI), given by mouth twice daily in the treatment of acute bacterial skin and skin structure infections (ABSSSI) due to staphylococci. Important aspects of the current study included a comparison of early response efficacy endpoints with end-of-treatment and follow-up endpoints. Many patients in the intent-to-treat population (n = 103) had significant comorbidities. The overall early response rate at day 3 was 97.3% (wound, 100%; abscess, 96.6%; cellulitis, 94.4%) in the microbiologically evaluable (ME) population. Within the ME population, 82.9% of patients had a ≥ 20% decrease in the area of erythema, and 77.9% of patients had a ≥ 20% decrease in the area of induration, on day 3. S. aureus was detected in 97.7% of patients (n = 37 patients with methicillin-resistant S. aureus [MRSA], and n = 39 with methicillin-sensitive S. aureus [MSSA]). No isolates had increased AFN-1252 MICs posttreatment. Microbiologic eradication rates for S. aureus were 93.2% at short-term follow-up (STFU) and 91.9% at long-term follow-up (LTFU) in the ME population. Eradication rates for MRSA and MSSA were 91.9% and 92.3%, respectively, at STFU and 91.9% and 89.7%, respectively, at LTFU. The most frequently reported drug-related adverse events, which were mostly mild or moderate, were headache (26.2%) and nausea (21.4%). These studies demonstrate that AFN-1252 is generally well tolerated and effective in the treatment of ABSSSI due to S. aureus, including MRSA. (This study has been registered at ClinicalTrials.gov under registration no. NCT01519492.).

In Vitro Activity of Ceftaroline against Staphylococcus aureus Isolates Collected in 2012 from Latin American Countries as Part of the AWARE Surveillance Program

The in vitro activities of ceftaroline and comparators, using broth microdilution, were determined against 1,066 Staphylococcus aureus isolates from hospitalized patients. Seventeen medical centers from Latin American countries contributed isolates. Methicillin-resistant S. aureus (MRSA) percentages ranged from 46% (Brazil) to 62% (Argentina). All methicillin-susceptible S. aureus (MSSA) isolates were susceptible to ceftaroline. Ceftaroline activity against MRSA varied with MIC90s of 0.5 (Venezuela) to 2 (Brazil, Chile, and Colombia) μg/ml, which was the highest MIC value. ST-5 was the most common sequence type.

Community-acquired pneumonia: An overview

Community-acquired pneumonia is still a significant cause of morbidity and mortality and is often misdiagnosed and inappropriately treated. Although it can be caused by a wide variety of micro-organisms, the pneumococcus, atypicals, such as Mycoplasma pneumoniae and Chlamydophila pneumoniae,Staphylococcus aureus and certain Gram-negative rods are the usual pathogens encountered. The site-of-care decision is critical in determining the site and type of care as well as the extent of diagnostic workup. Antimicrobial therapy should be started as soon as possible particularly in those requiring admission to hospital, but typically the physician does not know with any degree of certainty the identity of the etiologic pathogen. A number of national guidelines have been published to help the physician with this choice. The initial drug(s) can be modified if necessary if the pathogen and its antimicrobial susceptibility pattern becomes known. Adjunctive therapy such as pressors and fluid replacement are of value and macrolides appear to help as well, likely secondary to their immunomodulatory effects. Recent data also suggest a role for steroids.

Antimicrobial Susceptibility Profiles of Staphylococcus aureus Isolates Recovered from Humans, Environmental Surfaces, and Companion Animals in Households of Children with Community-Onset Methicillin-Resistant S. aureus Infections

Our objective was to determine the antibiotic susceptibility profiles of Staphylococcus aureus isolates recovered from 110 households of children with community-onset methicillin-resistant S. aureus (MRSA) infections. Cultures were obtained from household members, household objects, and dogs and cats, yielding 1,633 S. aureus isolates. The S. aureus isolates were heterogeneous, although more than half were methicillin resistant. The highest proportion of MRSA was found in bathrooms. The majority of isolates were susceptible to antibiotics prescribed in outpatient settings.

What's new in the treatment of serious MRSA infection?

PURPOSE OF REVIEW

Vancomycin has been the cornerstone of treatment for methicillin-resistant Staphylococcus aureus (MRSA) infections. This review describes new MRSA-active antibiotics that have recently been introduced and highlights emerging resistance.

RECENT FINDINGS

Elevations in the vancomycin minimum inhibitory concentration within the susceptible range are associated with treatment failure and mortality in the treatment of MRSA infections. Ceftaroline and ceftobiprole are anti-MRSA cephalosporins and are noninferior to comparator agents in the treatment of acute bacterial skin and skin structure infections (ABSSSIs) and pneumonia. Tedizolid is more potent than linezolid, has improved pharmacokinetics and reduced toxicity and is active against cfr-containing S. aureus. Telavancin now has approval for treatment of hospital-acquired pneumonia, and recent phase 2 trial data showed similar cure rates in S. aureus bacteremia. Dalbavancin and oritavancin are administered once weekly and are noninferior to comparators for acute bacterial skin and skin structure infections. Resistance has emerged against many new anti-MRSA antimicrobials including ceftaroline. Combination therapy of β-lactams with vancomycin or daptomycin is increasing.

SUMMARY

Several new MRSA-active agents are now approved for use, although much of the data is derived from treatment of acute bacterial skin and skin structure infections or pneumonia. Further studies are required for more invasive infections, such as bacteremia and endocarditis.

Treatment of methicillin-resistant Staphylococcus aureus infections: Importance of high vancomycin minumum inhibitory concentrations

Staphylococcus aureus (SA) infections remain a major cause of morbidity and mortality despite the availability of numerous effective anti-staphylococcal antibiotics. This organism is responsible for both nosocomial and community-acquired infections ranging from relatively minor skin and soft tissue infections to life-threatening systemic infections. The increasing incidence of methicillin-resistant strains has granted an increasing use of vancomycin causing a covert progressive increase of its minimum inhibitory concentration (MIC) (dubbed the MIC “creep”). In this way, the emergence of vancomycin-intermediate SA (VISA) strains and heteroresistant-VISA has raised concern for the scarcity of alternative treatment options. Equally alarming, though fortunately less frequent, is the emergence of vancomycin-resistant SA. These strains show different mechanisms of resistance but have similar problems in terms of therapeutic approach. Ultimately, various debate issues have arisen regarding the emergence of SA strains with a minimum inhibitory concentration sitting on the superior limit of the sensitivity range (i.e., MIC = 2 μg/mL). These strains have shown certain resilience to vancomycin and a different clinical behaviour regardless of vancomycin use, both in methicillin-resistant SA and in methicillin-sensitive SA. The aim of this text is to revise the clinical impact and consequences of the emergence of reduced vancomycin susceptibility SA strains, and the different optimal treatment options known.

Oritavancin for acute bacterial skin and skin structure infections

INTRODUCTION

Inpatient treatment of acute bacterial skin and skin structure infections (ABSSSIs) exerts a significant economic burden on the healthcare system. Oritavancin is a concentration-dependent, rapid bactericidal agent approved for the treatment of ABSSSIs. Its prolonged half-life with one-time intravenous (i.v.) dosing offers a potential solution to this burden. In addition, oritavancin represents an alternative therapy for Streptococci and multidrug-resistant Gram-positive bacteria including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. Animal models have also shown promising results with oritavancin for other disease states including those that require long courses of i.v.

THERAPY

AREAS COVERED

This review covers oritavancin's basic chemistry, spectrum of activity, pharmacodynamics/pharmacokinetics and efficacy in clinical trials, and provides expert opinion on future directions. To compose this review, a search of PubMed was performed, and articles written in the English language were selected based on full text availability.

EXPERT OPINION

If oritavancin is proven to be a cost-effective strategy for outpatient treatment and prevents complications of prolonged i.v. therapy, it will be sought as an alternative antibiotic therapy for ABSSSIs. In addition, further clinical data demonstrating efficacy in Gram-positive infections requiring prolonged therapy such as endocarditis and osteomyelitis could support oritavancin's success in the current market.

Desensitization to ceftaroline in a patient with multiple medication hypersensitivity reactions

PURPOSE

The case of a patient with multiple medication hypersensitivity reactions and a methicillin-resistant Staphylococcus aureus (MRSA) infection who underwent desensitization to ceftaroline is reported.

SUMMARY

A 32-year-old Caucasian woman with asthma, gastroesophageal reflux disease, heart murmur, and major depression was admitted for MRSA cellulitis with a subcutaneous abscess along the left sternomanubrial joint and clavicular osteomyelitis secondary to port placement after gastric bypass surgery. The patient had an extensive history of hypersensitivity reactions. Pertinent documented allergies were as follows: penicillin (anaphylaxis), daptomycin (anaphylaxis), vancomycin (hives), linezolid (hives), ertapenem (rash), ciprofloxacin (rash), and tigecycline (rash). The patient also reported previous reactions to aztreonam (unknown) and gentamicin (hives). The pharmacy was consulted to develop a desensitization protocol for ceftaroline. The desensitization protocol used three serial dilutions of ceftaroline to make 14 sequential infusions with escalating doses. Intramuscular epinephrine, i.v. diphenhydramine, and i.v. methylprednisolone were ordered as needed for the development of immediate hypersensitivity reactions during or after administration of ceftaroline. The cumulative dose (574.94 mg) was administered intravenously over 225 minutes with no breakthrough symptoms reported during or after the desensitization protocol. Ceftaroline fosamil 600 mg i.v. every 12 hours was continued for six weeks.

CONCLUSION

Desensitization to ceftaroline was conducted for a patient with extensive history of hypersensitivity reactions to other drugs, including penicillin-induced anaphylaxis. Desensitization and subsequent treatment with full doses of ceftaroline were accomplished without apparent adverse effects.

Ceftaroline Fosamil for the Treatment of Staphylococcus aureus Bacteremia Secondary to Acute Bacterial Skin and Skin Structure Infections or Community-Acquired Bacterial Pneumonia

BACKGROUND

The Clinical Assessment Program and Teflaro® Utilization Registry is designed to collect information on the clinical use of ceftaroline fosamil in the Unites States. This report presents data on the treatment of patients with Staphylococcus aureus bacteremia (SAB) secondary to acute bacterial skin and skin structure infections (ABSSSIs) or community-acquired bacterial pneumonia (CABP).

METHODS

Patients diagnosed with ABSSSI or CABP were identified through sequential review of randomly ordered charts generated from pharmacy listings from August 2011 to February 2013. Data were collected by chart review 30 days or more after completion of ceftaroline fosamil therapy.

RESULTS

Secondary SAB was reported in a total of 48 of 1428 evaluable patients (27 with ABSSSI, 21 with CABP). The mean (SD) patient age was 61 (15) years. At least 1 comorbidity was recorded for 74% of patients with ABSSSI and 81% with CABP. Methicillin-resistant S. aureus was isolated from 59% of patients with ABSSSI and 76% with CABP. The mean (SD) duration of ceftaroline fosamil therapy was 5.8 (4.8) days for ABSSSI and 7.0 (3.8) days for CABP. Clinical success among all patients with SAB treated with ceftaroline fosamil was 58% (52% for SAB secondary to ABSSSI, 67% for SAB secondary to CABP). Clinical success rates of methicillin-resistant S. aureus SAB were 50% (8/16) for ABSSSI and 63% (10/16) for CABP.

CONCLUSIONS

This study supports the use of ceftaroline fosamil as a viable treatment option in hospitalized patients with SAB secondary to ABSSSI or CABP. Further studies evaluating the use of ceftaroline fosamil for the treatment of SAB are warranted.

Ceftaroline fosamil for treating skin and skin structure infections or community-acquired pneumonia in patients with renal insufficiency

The Clinical Assessment Program and Teflaro(®) Utilization Registry (CAPTURE) is a multicenter retrospective study, conducted in the USA, describing the contemporary use of ceftaroline fosamil. Ceftaroline is primarily excreted by the kidneys and the dose should be reduced in patients with moderate to severe renal insufficiency. This article describes the clinical effectiveness of ceftaroline fosamil in the treatment of acute bacterial skin and skin structure infection (ABSSSI) or community-acquired bacterial pneumonia (CABP) patients with renal insufficiency. There were 985 ABSSSI patients and 344 CABP patients, of which 22 and 31%, respectively, had renal insufficiency. Ceftaroline fosamil was mostly administered to patients as second-line therapy. Overall clinical success was 78-91% among ABSSSI or CABP patients with renal insufficiency and, overall, >50% of patients were discharged to home. Ceftaroline fosamil is an effective treatment option for ABSSSI or CABP patients with renal insufficiency.

Ceftaroline desensitization procedure in a pregnant patient with multiple drug allergies

Validated skin testing is lacking for many drugs, including ceftaroline. The cross-reactivity between ceftaroline and other β-lactam antibiotics is unknown. We report a case of a pregnant patient with cystic fibrosis and multiple drug allergies who required ceftaroline for methicillin-resistant Staphylococcus aureus pneumonia and underwent an uncomplicated empiric desensitization procedure.

Antimicrobial activity of ceftaroline and other anti-infective agents against microbial pathogens recovered from the surgical intensive care patient population: a prevalence analysis

BACKGROUND

Ceftaroline is a new parenteral cephalosporin agent with excellent activity against methicillin-sensitive (MSSA) and resistant strains of Staphylococcus aureus (MRSA). Critically ill surgical patients are susceptible to infection, often by multi-drug-resistant pathogens. The activity of ceftaroline against such pathogens has not been described.

METHODS

Three hundred thirty-five consecutive microbial isolates were collected from surgical wounds or abscesses, respiratory, urine, and blood cultures from patients in the surgical intensive care unit (SICU) of a major tertiary medical center. Using Clinical and Laboratory Standards Institute (CLSI) standard methodology and published breakpoints, all aerobic, facultative anaerobic isolates were tested against ceftaroline and selected comparative antimicrobial agents.

RESULTS

All staphylococcal isolates were susceptible to ceftaroline at a breakpoint of ≤1.0 mcg/mL. In addition, ceftaroline exhibited excellent activity against all streptococcal clinical isolates and non-ESBL-producing strains of Enterobacteriaceae (93.5%) recovered from SICU patients. Ceftaroline was inactive against ESBL-producing Enterobacteriaceae, Pseudomonas aeruginosa, vancomycin-resistant enterococci, and selective gram-negative anaerobic bacteria.

CONCLUSIONS

At present, ceftaroline is the only cephalosporin agent that is active against community and healthcare-associated MRSA. Further studies are needed to validate the benefit of this novel broad-spectrum anti-infective agent for the treatment of susceptible serious infections in the SICU patient population.

Antibiotics for community-acquired pneumonia in adult outpatients

BACKGROUND

Lower respiratory tract infection (LRTI) is the third leading cause of death worldwide and the first leading cause of death in low-income countries. Community-acquired pneumonia (CAP) is a common condition that causes a significant disease burden for the community, particularly in children younger than five years, the elderly and immunocompromised people. Antibiotics are the standard treatment for CAP. However, increasing antibiotic use is associated with the development of bacterial resistance and side effects for the patient. Several studies have been published regarding optimal antibiotic treatment for CAP but many of these data address treatments in hospitalised patients. This is an update of our 2009 Cochrane Review and addresses antibiotic therapies for CAP in outpatient settings.

OBJECTIVES

To compare the efficacy and safety of different antibiotic treatments for CAP in participants older than 12 years treated in outpatient settings with respect to clinical, radiological and bacteriological outcomes.

SEARCH METHODS

We searched CENTRAL (2014, Issue 1), MEDLINE (January 1966 to March week 3, 2014), EMBASE (January 1974 to March 2014), CINAHL (2009 to March 2014), Web of Science (2009 to March 2014) and LILACS (2009 to March 2014).

SELECTION CRITERIA

We looked for randomised controlled trials (RCTs), fully published in peer-reviewed journals, of antibiotics versus placebo as well as antibiotics versus another antibiotic for the treatment of CAP in outpatient settings in participants older than 12 years of age. However, we did not find any studies of antibiotics versus placebo. Therefore, this review includes RCTs of one or more antibiotics, which report the diagnostic criteria and describe the clinical outcomes considered for inclusion in this review.

DATA COLLECTION AND ANALYSIS

Two review authors (LMB, TJMV) independently assessed study reports in the first publication. In the 2009 update, LMB performed study selection, which was checked by TJMV and MMK. In this 2014 update, two review authors (SP, SM) independently performed and checked study selection. We contacted trial authors to resolve any ambiguities in the study reports. We compiled and analysed the data. We resolved differences between review authors by discussion and consensus.

MAIN RESULTS

We included 11 RCTs in this review update (3352 participants older than 12 years with a diagnosis of CAP); 10 RCTs assessed nine antibiotic pairs (3321 participants) and one RCT assessed four antibiotics (31 participants) in people with CAP. The study quality was generally good, with some differences in the extent of the reporting. A variety of clinical, bacteriological and adverse events were reported. Overall, there was no significant difference in the efficacy of the various antibiotics. Studies evaluating clarithromycin and amoxicillin provided only descriptive data regarding the primary outcome. Though the majority of adverse events were similar between all antibiotics, nemonoxacin demonstrated higher gastrointestinal and nervous system adverse events when compared to levofloxacin, while cethromycin demonstrated significantly more nervous system side effects, especially dysgeusia, when compared to clarithromycin. Similarly, high-dose amoxicillin (1 g three times a day) was associated with higher incidence of gastritis and diarrhoea compared to clarithromycin, azithromycin and levofloxacin.

AUTHORS' CONCLUSIONS

Available evidence from recent RCTs is insufficient to make new evidence-based recommendations for the choice of antibiotic to be used for the treatment of CAP in outpatient settings. Pooling of study data was limited by the very low number of studies assessing the same antibiotic pairs. Individual study results do not reveal significant differences in efficacy between various antibiotics and antibiotic groups. However, two studies did find significantly more adverse events with use of cethromycin as compared to clarithromycin and nemonoxacin when compared to levofloxacin. Multi-drug comparisons using similar administration schedules are needed to provide the evidence necessary for practice recommendations. Further studies focusing on diagnosis, management, cost-effectiveness and misuse of antibiotics in CAP and LRTI are warranted in high-, middle- and low-income countries.

Ceftaroline is active against heteroresistant methicillin-resistant Staphylococcus aureus clinical strains despite associated mutational mechanisms and intermediate levels of resistance

Methicillin-resistant Staphylococcus aureus (MRSA) is an important infectious human pathogen responsible for diseases ranging from skin and soft tissue infections to life-threatening endocarditis. β-Lactam resistance in MRSA involves acquisition of penicillin-binding protein 2a (PBP2a), a protein with low affinity for β-lactams that mediates cell wall assembly when the normal staphylococcal PBPs (PBP1 to -4) are blocked by these agents. Many MRSA strains display heterogeneous expression of resistance (HeR) against β-lactam antibiotics. The β-lactam-mediated homoresistant (HoR) phenotype is associated with both expression of the mecA gene and activation of the LexA-RecA-mediated SOS response, a regulatory network induced in response to DNA damage. Ceftaroline (CPT) is the only FDA-approved cephalosporin targeting PBP2a. We investigated the mechanistic basis of CPT activity against HeR-MRSA strains, including a set of strains displaying an intermediate level of resistance to CPT. Mechanistically, we found that 1 exposure of HeR-MRSA to subinhibitory concentrations of CPT selected for the HoR derivative activated the SOS response and increased mutagenesis. Importantly, CPT-selected HoR cells remained susceptible to CPT while still being resistant to most β-lactams, and 2-CPT activity in HeR-MRSA resided in an attenuated induction of mecA expression in comparison to other β-lactams. In addition, 3-CPT intermediate-resistant strains displayed a significant increase in CPT-induced mecA expression accompanied by mutations in PBP2, which together may interfere with the complete repression by CPT of both PBP2a and PBP2a-PBP2 interactions and thus be a determining factor in the low level of CPT resistance in the absence of mecA gene mutations. The present study provides mechanistic evidence that CPT represents an alternative therapeutic option for the treatment of heteroresistant MRSA strains.

Ceftaroline fosamil for the treatment of acute bacterial skin and skin structure infections in obese patients

BACKGROUND

Ceftaroline fosamil is a broad-spectrum antibiotic approved by the US Food and Drug Administration (FDA) for the treatment of acute bacterial skin and skin structure infections (ABSSSIs) and community-acquired bacterial pneumonia. The Clinical Assessment Program and Teflaro Utilization Registry (CAPTURE) is a multicenter registry study of patients treated with ceftaroline fosamil in the United States for ABSSSI or community-acquired bacterial pneumonia.

OBJECTIVE

To describe the clinical effectiveness of ceftaroline fosamil in the treatment of ABSSSI in obese patients [body mass index (BMI) ≥ 30] compared with patients with a normal BMI (18.5 to ≤ 24.9).

METHODS

Data were collected at US study centers by randomly ordered chart review.

RESULTS

Data from 261 patients with a normal BMI and 690 patients with an obese BMI were collected. The percentage of males was higher in the normal BMI than in the obese category (58.2% and 49.0%, respectively). The mean and median ages at baseline were similar. Most patients (91%) were treated on a general hospital ward, and the mean and median lengths of stay were similar between the 2 groups (approximately 11 days and 7 days, respectively). A total of 73.2% of normal BMI patients and 77.5% of obese patients were discharged to home. Rates of diabetes mellitus were 26.4% in the normal BMI group and 55.1% in the obese group. Methicillin-resistant Staphylococcus aureus was isolated from 26.1% of normal BMI patients and 20.5% of obese patients (16.4% morbidly obese subset). Mean treatment duration for all patients was 5.9 days. Of patients with a normal BMI, 57.5% received ceftaroline fosamil as monotherapy as did 63.3% of obese patients. Clinical success was high in both the normal BMI (85.1%) and the obese (89.0%) groups.

CONCLUSION

Ceftaroline fosamil is an effective treatment option for obese patients with ABSSSI with a similar clinical success rate, mean and median length of stay, and discharge destination to home when compared with normal BMI patients.

Contemporary use of ceftaroline fosamil for the treatment of community-acquired bacterial pneumonia: CAPTURE study experience

The Clinical Assessment Program and Teflaro(®) Utilization Registry (CAPTURE) is a multicenter cohort study designed to collect information on the contemporary use of ceftaroline fosamil in the US. Data collected from 398 evaluable patients with community-acquired bacterial pneumonia (CABP) (mean age 64 years) during the first 18 months of the study are presented. Most patients had co-morbidities (76%; primarily structural lung disease), and ≧2 signs and symptoms of CABP (76%). Overall clinical success was 79% which varied little with ceftaroline fosamil usage (monotherapy vs concurrent therapy; first-line vs second-line therapy). Most patients were discharged home (60%) or to another healthcare facility (35%). These data suggest that ceftaroline, in contemporary clinical use, is an effective antibiotic for the treatment of patients with CABP, including those with significant co-morbidities or who required a change of their prior antibiotic therapy.