Ceftaroline for Severe Methicillin-Resistant Staphylococcus aureus Infections: A Systematic Review

Efficacy and Safety of Vancomycin, Linezolid, and Ceftaroline in the Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA): A Systematic Review and Meta-Analysis

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the world's most serious healthcare issues, causing morbidity, mortality, and high healthcare costs, making effective treatment strategies essential. This meta-analysis assessed the comparative effectiveness and safety of ceftaroline, linezolid, and vancomycin in treating MRSA infections. Searches were undertaken across major electronic databases, including PubMed, Cochrane CENTRAL, Embase, and Web of Science, from 2000 to 2024. A total of 24 studies (17 randomized controlled trials (RCTs) and seven observational studies) involving 11,332 patients met the inclusion criteria. Patients on vancomycin treatment were more likely to have lower odds of being cured than controls (OR 0.68; 95% CI (0.58, 0.81), p < 0.0001), especially when compared to linezolid (OR 0.61; 95% CI (0.49, 0.74), p < 0.00001). Furthermore, mortality rates were significantly higher in vancomycin-treated patients than in controls (OR 1.25; 95% CI (1.00, 1.56), p = 0.05) and more precisely than in linezolid (OR 1.29; 95% CI (1.03, 1.62), p = 0.03). Microbiological eradication rates were not statistically different between vancomycin and the comparators (OR, 0.82; 95% CI (0.63, 1.07), p = 0.14). Safety analysis demonstrated comparable adverse event profiles between vancomycin and linezolid for thrombocytopenia, anemia, and hepatotoxicity. Although vancomycin remains a viable option owing to its accessibility and cost-effectiveness, our findings suggest that newer alternatives, particularly linezolid, may offer superior clinical outcomes in specific MRSA infections, especially in cases of pneumonia or high-risk patients. These results have important implications for clinical practice and antimicrobial stewardship programs and support a more nuanced approach to MRSA treatment based on patient-specific factors, infection characteristics, and local resources.

Relationship between the strength of biofilm production and the presence of pvl and mecA genes in Staphylococcus aureus isolated from skin and soft tissue infections

This research sought to investigate the association between the occurrence of the pvl and mecA genes and the strength of biofilm formation, as well as to assess the efficacy of vancomycin and ceftaroline against Staphylococcus aureus strains obtained from skin and soft tissue infections (SSTIs). A total of 134 S. aureus isolates were collected from SSTI patients and identified through standard microbiological techniques. Vancomycin and ceftaroline susceptibility testing were performed using the agar dilution and disc diffusion methods, respectively. PCR analysis was conducted to identify the nuc, mecA, and pvl genes. Biofilm production was measured using the tissue culture plate method. Methicillin-resistant S. aureus (MRSA) represented 58.2 % of the isolates. All isolates displayed biofilm-forming capability, with 10.4 % classified as high-grade biofilm producers, 85.7 % of which were positive for the mecA gene (P = 0.02). 16.4 % of the isolates had pvl gene and 59 % of PVL-positive strains identified as MRSA. Most of the low-grade biofilm producers had the pvl gene (P = 0.03). Vancomycin susceptibility was observed in 98.5 % of isolates, with an MIC₅₀ of 1 μg/mL in 51.4 % of cases. Among MRSA strains, 1.4 % exhibited intermediate resistance to vancomycin, with MICs between 4 and 8 μg/mL. No resistance to ceftaroline was found. The results demonstrate a significant association between biofilm production strength and the occurrence of the mecA and pvl genes; mecA correlated with increased biofilm production, while pvl was associated with lower biofilm levels. These findings offer valuable insights for future studies, suggesting that ceftaroline could be an effective alternative to vancomycin for treating MRSA-related SSTIs, particularly given the increasing resistance to vancomycin.

Heartfelt Impact: A Descriptive Analysis of Ceftaroline-Containing Regimens in Endocarditis due to Methicillin-Resistant Staphylococcus aureus

INTRODUCTION

Infective endocarditis (IE) due to methicillin-resistant Staphylococcus aureus (MRSA) is characterized by frequent treatment failure to first-line agents and high mortality, necessitating use of alternative management strategies. Ceftaroline fosamil (CPT) is a cephalosporin antibiotic with activity against MRSA but without regulatory approval for the indication of IE. This study describes clinical experience with CPT-based regimens utilized in MRSA-IE.

METHODS

This is a retrospective, observational, descriptive analysis of patients from two major urban medical centers in Detroit, Michigan from 2011 to 2023. Included adult patients (≥ 18 years) had ≥ 1 positive blood culture for MRSA, met definitive clinical criteria for IE, and received CPT for ≥ 72 h. The primary outcome was treatment failure, defined as a composite of 30-day all-cause mortality from index culture or failure to improve or resolve infectious signs/symptoms after CPT initiation.

RESULTS

Seventy patients were included. The median (interquartile range [IQR]) age was 51 (34-63) years and 45.7% were male. Persons with injection drug use (PWID) made up 55.7% of the cohort and right-sided IE was the most prevalent subtype (50.0%). CPT was frequently employed second-line or later, often in combination with vancomycin (10.0%) or daptomycin (72.9%). Overall, 31.4% experienced treatment failure and 30-day all-cause mortality occurred in 15.7%.

CONCLUSIONS

These findings illustrate the challenges posed by MRSA-IE, including frequent treatment failures, and highlight the utilization of CPT as salvage therapy. Comparative studies are needed to more clearly define its role in MRSA-IE.

Infective Endocarditis by Biofilm-Producing Methicillin-Resistant Staphylococcus aureus-Pathogenesis, Diagnosis, and Management

Infective endocarditis (IE) is a life-threatening condition with increasing global incidence, primarily caused by Staphylococcus aureus, especially methicillin-resistant strains (MRSA). Biofilm formation by S. aureus is a critical factor in pathogenesis, contributing to antimicrobial resistance and complicating the treatment of infections involving prosthetic valves and cardiovascular devices. Biofilms provide a protective matrix for MRSA, shielding it from antibiotics and host immune defenses, leading to persistent infections and increased complications, particularly in cases involving prosthetic materials. Clinical manifestations range from acute to chronic presentations, with complications such as heart failure, embolic events, and neurological deficits. Diagnosis relies on the Modified Duke Criteria, which have been updated to incorporate modern cardiovascular interventions and advanced imaging techniques, such as PET/CT (positron emission tomography, computed tomography), to improve the detection of biofilm-associated infections. Management of MRSA-associated IE requires prolonged antimicrobial therapy, often with vancomycin or daptomycin, needing a combination of antimicrobials in the setting of prosthetic materials and frequently necessitates surgical intervention to remove infected prosthetic material or repair damaged heart valves. Anticoagulation remains controversial, with novel therapies like dabigatran showing potential benefits in reducing thrombus formation. Despite progress in treatment, biofilm-associated resistance poses ongoing challenges. Emerging therapeutic strategies, including combination antimicrobial regimens, bacteriophage therapy, antimicrobial peptides (AMPs), quorum sensing inhibitors (QSIs), hyperbaric oxygen therapy, and nanoparticle-based drug delivery systems, offer promising approaches to overcoming biofilm-related resistance and improving patient outcomes. This review provides an overview of the pathogenesis, current management guidelines, and future directions for treating biofilm-related MRSA IE.

In vitro identification of underutilized β-lactam combinations against methicillin-resistant Staphylococcus aureus bacteremia isolates

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is a serious clinical challenge with high mortality rates. Antibiotic combination therapy is currently used in cases of persistent infection; however, the limited development of new antibiotics will likely increase the need for combination therapy, and better methods are needed for identifying effective combinations for treating persistent bacteremia. To identify pairwise combinations with the most consistent potential for benefit compared to monotherapy with a primary anti-MRSA agent, we conducted a systematic study with an in vitro high-throughput methodology. We tested daptomycin and vancomycin each in combination with gentamicin, rifampicin, cefazolin, and oxacillin, and ceftaroline with daptomycin, gentamicin, and rifampicin. Combining cefazolin with daptomycin lowered the daptomycin concentration required to reach 95% growth inhibition (IC95) for all isolates tested and lowered daptomycin IC95 below the sensitivity breakpoint for five out of six isolates that had daptomycin minimum inhibitory concentrations at or above the sensitivity breakpoint. Similarly, vancomycin IC95s were decreased when vancomycin was combined with cefazolin for 86.7% of the isolates tested. This was a higher percentage than was achieved by adding any other secondary antibiotic to vancomycin. Adding rifampicin to daptomycin or vancomycin did not always reduce IC95s and failed to produce synergistic interaction in any of the isolates tested; the addition of rifampicin to ceftaroline was frequently synergistic and always lowered the amount of ceftaroline required to reach the IC95. These analyses rationalize further in vivo evaluation of three drug pairs for MRSA bacteremia: daptomycin+cefazolin, vancomycin+cefazolin, and ceftaroline+rifampicin.IMPORTANCEBloodstream infections caused by methicillin-resistant Staphylococcus aureus (MRSA) have a high mortality rate despite the availability of vancomycin, daptomycin, and newer antibiotics including ceftaroline. With the slow output of the antibiotic pipeline and the serious clinical challenge posed by persistent MRSA infections, better strategies for utilizing combination therapy are becoming increasingly necessary. We demonstrated the value of a systematic high-throughput approach, adapted from prior work testing antibiotic combinations against tuberculosis and other mycobacteria, by using this approach to test antibiotic pairs against a panel of MRSA isolates with diverse patterns of antibiotic susceptibility. We identified three antibiotic pairs-daptomycin+cefazolin, vancomycin+cefazolin, and ceftaroline+rifampicin-where the addition of the second antibiotic improved the potency of the first antibiotic across all or most isolates tested. Our results indicate that these pairs warrant further evaluation in the clinical setting.

Ceftaroline for Central Nervous System Infections: Case Report of a Young Infant, and Scoping Review

BACKGROUND

Managing health care acquired and device-associated intracranial infections in young children can be challenging given adverse antibiotic side effects and difficulties in achieving adequate central nervous system (CNS) antibiotic concentrations. Ceftaroline is a cephalosporin with a favorable safety profile and activity against methicillin-resistant Staphylococci and several Gram-negative organisms. Published data on the use of ceftaroline for CNS infections in children and adults are limited.

METHODS

We describe a 2-month-old infant with ventriculo-subgaleal shunt-associated methicillin-resistant Staphylococcus epidermidis ventriculitis, which was successfully treated with ceftaroline, in addition to vancomycin and rifampin. We conducted a scoping review of English-language literature retrieved from PubMed, EMBASE and Web of Science that assessed the use of ceftaroline for CNS infections.

RESULTS

We identified 22 articles for inclusion in our review, which described 92 unique patients, of whom 2 were <21 years old. Ceftaroline was commonly used in conjunction with other antibiotics to treat infections caused by Staphylococcus aureus , coagulase-negative Staphylococci and Streptococcus pneumoniae . Most case reports described clinical success with ceftaroline, though small case series and cohort studies yielded mixed efficacy assessments. Adverse effects attributed to ceftaroline were rare and included reversible myelosuppression, eosinophilia, hepatotoxicity and nephrotoxicity. Pharmacokinetic/pharmacodynamic studies suggested similar CNS penetration through inflamed meninges as other beta lactam antibiotics.

CONCLUSIONS

We identified a growing body of published evidence supporting the use of ceftaroline in combination with other agents for the treatment of CNS infections. In absence of clinical trials, additional real-world data are needed to define the efficacy and safety of ceftaroline for children and adults with CNS infections.

Short versus long duration of ceftaroline combination therapy and outcomes in persistent or high-grade MRSA bacteremia: A retrospective single-center study

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is associated with high mortality rates. Despite antibiotic therapy, persistent bacteremia is challenging to treat. Combination therapy with ceftaroline has emerged as a potential treatment option; however, the optimal duration and clinical implications after bacteremia clearance are unknown.

METHODS

This retrospective cohort study examined patients with high-grade or persistent MRSA bacteremia who were treated with ceftaroline combination therapy at the University of New Mexico Hospital between January 2014 and June 2021. Patients were categorized into short- (<7 days) or long-duration (≥7 days) groups based on the duration of combination therapy after bacteremia clearance. Outcomes included 30-day all-cause mortality, bacteremia recurrence, post-bacteremia clearance length of stay, and adverse events.

RESULTS

A total of 32 patients were included in this study. The most common sources of bacteremia were bone/joint and endovascular (28.1%, 9/32 each). The median duration of combination therapy after clearance was seven days (IQR 2.8, 11). Patients in the long-duration group had a lower Charlson comorbidity index (1.0 vs 5.5, p = 0.017) than those in the short-duration group. After adjusting for confounders, there was no significant difference in the 30-day all-cause mortality between the groups (AOR 0.17, 95% CI 0.007-1.85, p = 0.18). No association was found between combination therapy duration and recurrence (OR 2.53, 95% CI 0.19-inf, p = 0.24) or adverse drug events (OR 3.46, 95% CI 0.39-74.86, p = 0.31). After controlling for total hospital length of stay, there was no significant difference in the post-bacteremia clearance length of stay between the two groups (p = 0.37).

CONCLUSIONS

Prolonging ceftaroline combination therapy after bacteremia clearance did not significantly improve outcomes in patients with persistent or high-grade MRSA bacteremia. The limitations of this study warrant cautious interpretation of its results. Larger studies are needed to determine the optimal duration and role of combination therapy for this difficult-to-treat infection.

Getting to the heart of the matter-are two agents really better than one for the treatment of staphylococcal infective endocarditis?

The recently published European Society of Cardiology guidelines for infective endocarditis management recommends daptomycin combination therapy for the treatment of staphylococcal endocarditis in severe penicillin allergy, rather than daptomycin monotherapy. We discuss the evidence base behind this recommendation, highlighting concerns regarding the lack of robust clinical studies, increased cost and logistical considerations, and adverse effects of combination therapy. Although further studies are required to elucidate the role of combination vs monotherapy in these patients, we propose a pragmatic management approach to reduce the risk of adverse antimicrobial side effects and limit costs, while aiming to maintain treatment efficacy.

The Home Environment Is a Reservoir for Methicillin-Resistant Coagulase-Negative Staphylococci and Mammaliicocci

Coagulase-negative staphylococci (CoNS) and mammaliicocci are opportunistic human and animal pathogens, often resistant to multiple antimicrobials, including methicillin. Methicillin-resistant CoNS (MRCoNS) have traditionally been linked to hospitals and healthcare facilities, where they are significant contributors to nosocomial infections. However, screenings of non-hospital environments have linked MRCoNS and methicillin-resistant mammaliicocci (MRM) to other ecological niches. The aim of this study was to explore the home environment as a reservoir for MRCoNS and MRM. A total of 33 households, including households with a dog with a methicillin-resistant staphylococcal infection, households with healthy dogs or cats and households without pets, were screened for MRCoNS and MRM by sampling one human, one pet (if present) and the environment. Samples were analyzed by a selective culture-based method, and bacterial species were identified by MALDI-TOF MS and tested for antibiotic susceptibility by the agar disk diffusion method. Following whole-genome sequencing, a large diversity of SCCmec elements and sequence types was revealed, which did not indicate any clonal dissemination of specific strains. Virulome and mobilome analyses indicated a high degree of species specificity. Altogether, this study documents that the home environment is a reservoir for a variety of MRCoNS and MRM regardless of the type of household.

Antibiotic Resistance to Molecules Commonly Prescribed for the Treatment of Antibiotic-Resistant Gram-Positive Pathogens: What Is Relevant for the Clinician?

Antibiotic resistance in Gram-positive pathogens is a relevant concern, particularly in the hospital setting. Several antibiotics are now available to treat these drug-resistant pathogens, such as daptomycin, dalbavancin, linezolid, tedizolid, ceftaroline, ceftobiprole, and fosfomycin. However, antibiotic resistance can also affect these newer molecules. Overall, this is not a frequent phenomenon, but it is a growing concern in some settings and can compromise the effectiveness of these molecules, leaving few therapeutic options. We reviewed the available evidence about the epidemiology of antibiotic resistance to these antibiotics and the main molecular mechanisms of resistance, particularly methicillin-resistant Sthaphylococcus aureus, methicillin-resistant coagulase-negative staphylococci, vancomycin-resistant Enterococcus faecium, and penicillin-resistant Streptococcus pneumoniae. We discussed the interpretation of susceptibility tests when minimum inhibitory concentrations are not available. We focused on the risk of the emergence of resistance during treatment, particularly for daptomycin and fosfomycin, and we discussed the strategies that can be implemented to reduce this phenomenon, which can lead to clinical failure despite appropriate antibiotic treatment. The judicious use of antibiotics, epidemiological surveillance, and infection control measures is essential to preserving the efficacy of these drugs.

Efficacy of ceftaroline and rifampin, alone or combined, in a rat model of methicillin-resistant Staphylococcus epidermidis osteomyelitis without implant

IMPORTANCE

Methicillin-resistant Staphylococcus epidermidis (MRSE) contributes to a high percentage of orthopedic infections, and their treatment represents a huge challenge. The present study aimed to evaluate the efficacy of ceftaroline alone or combined with rifampin in a rat MRSE osteomyelitis model and the bone penetration of ceftaroline. A ceftaroline monotherapy showed a significant bacterial reduction in infected bones after a 7-day period of treatment. The combination ceftaroline plus rifampin leveraged rifampin's bactericidal activity, shortening the duration of positive culture in infected animals. These results suggest that ceftaroline and rifampin combination therapy could represent a valuable therapeutic option for human MRSE osteomyelitis and deserves further preclinical and clinical evaluation.

Ceft-to-Ceft Study: Real-Life Experience with Ceftaroline and Ceftobiprole in Treatment of the Principal Infectious Syndromes in a Spanish Multicenter Hospital Cohort

BACKGROUND

To compare the real-life effectiveness and safety of ceftaroline fosamil (ceftaroline-F) and ceftobiprole medocaril (ceftobiprole-M) for infections in hospitalized patients.

METHODS

This comparative, observational, retrospective, and multicenter Spanish study included patients receiving outpatient parenteral antimicrobial therapy (OPAT) and hospitalized patients treated for at least 48 h with ceftaroline-F or ceftobiprole-M between their first incorporation in the clinical protocol of each hospital and 31 July 2022.

RESULTS

Ceftaroline-F was administered to 227 patients and ceftobiprole-M to 212. In comparison to the latter, ceftaroline-F-treated participants were younger (63.02 vs. 66.40 years, OR 1.1; 95%CI: 1.001-1.05) and had higher rates of septic shock (OR 0.27; 95%CI: 0.09-0.81) and higher frequencies of targeted (57.7 vs. 29.7%; OR: 0.35; 95%CI: 0.18-0.69) and combined (89.0 vs. 45.8%, OR: 0.13; 95%CI: 0.06-0.28) therapies that were second line or more (82.4% vs. 64.6%%; OR 0.35; 95%CI: 0.18-0.69), and higher rates of infections due to Gram-positive cocci (92.7 vs. 64.7%, p = 0.001), bacteremia (51.9 vs. 21.7%, p = 0.001), infective endocarditis (24.2 vs. 2.4%, p = 0.0001), and mechanical ventilation-associated pneumonia (8.8 vs. 2.4%, p = 0.0001). Ceftobiprole-M was more frequently administered against polymicrobial infections (38.1 vs. 14.0%, p = 0.001), those produced by Gram-negative bacilli (19.7 vs. 6.0%, p = 0.0001), nosocomial pneumonia (33 vs. 10.6%, p = 0.0001), and skin and soft-tissue infections (25.4 vs. 10.1%, p = 0.0001). Patients treated with ceftaroline-F had a longer hospital stay (36 (IQR: 19-60) vs. 19.50 (IQR: 12-30.75, p = 0.0001) days), with no difference in infection-related mortality at 14 (13.2 vs. 8.0%, p = 0.078) or 28 (4.8 vs. 3.3%, p = 0.415) days or in dropout rate for adverse effects (2.2 vs. 0.9%; p = 1).

CONCLUSIONS

The fifth-generation cephalosporins, ceftaroline-F and ceftobiprole-M, are safe and effective in real life, with no difference between them in health outcomes.

Contemporary Management of Staphylococcus aureus Bacteremia-Controversies in Clinical Practice

Staphylococcus aureus bacteremia (SAB) carries a high risk for excess morbidity and mortality. Despite its prevalence, significant practice variation continues to permeate clinical management of this syndrome. Since the publication of the 2011 Infectious Diseases Society of America (IDSA) guidelines on management of methicillin-resistant Staphylococcus aureus infections, the field of SAB has evolved with the emergence of newer diagnostic strategies and therapeutic options. In this review, we seek to provide a comprehensive overview of the evaluation and management of SAB, with special focus on areas where the highest level of evidence is lacking to inform best practices.

Tricuspid Valve Endocarditis Due to Methicillin-Resistant Staphylococcus aureus in a Previously Healthy Young Patient without a Drug Abuse History: A Case Report and a Review of the Literature

Right-sided infective endocarditis due to methicillin-resistant Staphylococcus aureus (MRSA) is strongly associated with intravenous drug abuse, congenital heart disease, or previous medical treatment and is rare in healthy patients without a history of drug abuse. Here, we present a case of an 18-year-old male with no drug abuse history and no medical burden who was diagnosed with MRSA tricuspid valve endocarditis. Due to initial symptoms which indicated community-acquired pneumonia and radiological finding of interstitial lesions, empiric therapy with ceftriaxone and azithromycin was started. After the detection of Gram-positive cocci in clusters in several blood culture sets, endocarditis was suspected, and flucloxacillin was added to the initial therapy. As soon as methicillin resistance was detected, the treatment was switched to vancomycin. Transesophageal echocardiography established the diagnosis of right-sided infective endocarditis. A toxicological analysis of hair was carried out, and no presence of narcotic drugs was found. After six weeks of therapy, the patient was fully recovered. Exceptionally, tricuspid valve endocarditis can be diagnosed in previously healthy people who are not drug addicts. As the clinical presentation commonly resembles a respiratory infection, a misdiagnosis is possible. Although MRSA rarely causes community-acquired infections in Europe, clinicians should be aware of this possibility.

Development and validation of an LC-MS/MS method to quantify ceftaroline in microdialysate samples from plasma and brain: Application to a preclinical pharmacokinetic investigation

A bioanalytical LC-MS/MS method was developed and validated to determine ceftaroline in microdialysate samples from plasma and brain. Ceftaroline was separated using a C18 column and a mobile phase consisting of water and acetonitrile, both with 5 mM of ammonium formate and acid formic 0.1%, eluted as gradient. Ceftaroline was monitored using electrospray ionization operating on positive mode (ESI+) monitoring the transition 604.89 > 209.3 m/z. The method showed linearity in the concentration range of 0.5-500 ng/mL for brain microdialysate and 0.5-2500 ng/mL for plasma microdialysate with coefficients of determination ≥0.997. The inter-and intra-day precision, the accuracy, and the stability of the drug in different conditions were in accordance with the acceptable limits determined by international guidelines. Plasma pharmacokinetics and brain distribution of the drug were carried out after intravenous administration of 20 mg/kg of ceftaroline to male Wistar rats. The estimated geometric mean (geometric coefficient of variation) area under the curve (AUC_0-∞) was 4.68 (45.8%) mg·h/L and 1.20 (54.2%) mg·h/L for plasma and brain, respectively, resulting in a brain exposure of about 33% (AUC_{free brain}/AUC_{free plasma}). The results indicate that ceftaroline presents good penetration in the brain when considering free plasma and free brain concentrations.

New Antibiotics for Staphylococcus aureus Infection: An Update from the World Association of Infectious Diseases and Immunological Disorders (WAidid) and the Italian Society of Anti-Infective Therapy (SITA)

Staphylococcus aureus is an extremely virulent pathogen that is capable of quickly evolving and developing antibiotic resistance. To overcome this problem, new antibiotics have been developed. Some of these have been licenced for use in clinical practice, mainly for the treatment of adults with acute skin and soft tissue infections, in addition to both community-acquired pneumonia (CAP) and nosocomial pneumonia (hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia). In this paper, the main characteristics and clinical use of new licenced anti-staphylococcal drugs have been discussed. In vitro studies have demonstrated that some new anti-staphylococcal antibiotics have better antimicrobial activity and, at least in certain cases, more favourable pharmacokinetic properties and higher safety and tolerability than the presently available anti-staphylococcal drugs. This suggests that they may have a potential use in reducing the risk of failure of S. aureus therapy. However, an in-depth analysis of microbiological and clinical studies carried out with these new drugs seems to indicate that further studies need to be conducted before the problem of resistance of S. aureus to the antibiotics available today can be completely solved. Considering the overall available research, the drugs that are active against S. aureus appear to present a great therapeutic opportunity for overcoming resistance to traditional therapy. There are advantages in the pharmacokinetic characteristics of some of these drugs and they have the potential to reduce hospital stays and economic costs associated with their use.

Potential Failure of Vancomycin Dosing Using AUC/MIC in a Patient With Purulent Methicillin-Resistant Staphylococcus aureus Pericarditis

Objective: The objective of this case report is to describe utilization of area under the curve (AUC)/minimum inhibitory concentration (MIC) vancomycin dosing with variable MIC results in a patient with methicillin-resistant Staphylococcus aureus (MRSA) purulent pericarditis. Case: A 57-year-old Caucasian male presented with cardiac tamponade and pulmonary emboli. Echocardiogram showed moderate-large pericardial effusion with signs of early tamponade physiology. Pericardiocentesis removed serosanguinous, straw yellow fluid. Blood and pericardial cultures revealed MRSA. Patient was then initiated on vancomycin with an initial AUC of 415. MIC of repeat blood cultures were inconsistent. After 8 days of persistent bacteremia, patient was transitioned to daptomycin and ceftaroline with blood culture clearance within 48 hours. Discussion/Conclusion: Guidelines recommend AUC/MIC vancomycin dosing in patients with MRSA bacteremia. Literature regarding treatment of MRSA purulent pericarditis is limited to case reports. Evidence shows variation in MIC results dependent on analysis methods. Further studies on obtaining accurate MIC values and use of AUC/MIC dosing for MRSA purulent pericarditis are prudent to provide appropriate therapy in these patients as mortality is high.

Current and emerging drug treatment strategies to tackle invasive community-associated methicillin-resistant Staphylococcus aureus (MRSA) infection: what are the challenges?

INTRODUCTION

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections represent a leading cause of purulent skin and soft tissue infections in some geographical regions. Traditionally, 'old antibiotics' such as trimethoprim-sulfamethoxazole, tetracyclines, clindamycin, chloramphenicol,vancomycin, and teicoplanin have been used to treat these infections, but these were often associated with low efficacy and excessive side effects and toxicity, especially nephrotoxicity. Along with the development of new compounds, the last decade has seen substantial improvements in the management of CA-MRSA infections.

AREAS COVERED

In this review, the authors discuss the current and emerging drug treatment strategies to tackle invasive CA-MRSA infections. Articles reported in this review were selected from through literature searches using the PubMed database.

EXPERT OPINION

The availability of new drugs showing a potent in vitro activity against CA-MRSA represents a unique opportunity to face the threat of resistance while potentially reducing toxicity. All these compounds represent promising options to enhance our antibiotic armamentarium. However, data regarding the use of these new drugs in real-life studies are limited and their best placement in therapy and in terms of optimization of medical resources and balance of cost-effectiveness requires further investigation.

Ceftaroline Susceptibility among Isolates of MRSA: A Comparison of EUCAST and CLSI Breakpoints

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is an important bacterial pathogen causing a number of community-acquired and nosocomial infections. Ceftaroline fosamil is a fifth generation cephalosporin, approved for the treatment of infections caused by MRSA. The main objective of this study was to estimate the susceptibility of ceftaroline among isolates of MRSA by using CLSI and EUCAST breakpoints.

Materials and Methods

Fifty non-duplicate isolates of MRSA were included in the study. Ceftaroline susceptibility was done using E-strip test and interpreted using CLSI and EUCAST breakpoints.

Results

Susceptible isolates were equal (42%) by both CLSI and EUCAST, while resistant isolates were more commonly seen in EUCAST (50%). Ceftaroline MIC ranged from 0.25- >32µg/ml. All the isolates were sensitive to Teicoplanin and Linezolid.

Conclusions

Resistant isolates were less (30%) while using the CLSI 2021 criteria probably due to the inclusion of SDD category. Our study showed that Fourteen isolates (28%) had Ceftaroline MIC >32µg/ml, which is an alarming finding. The high percentage of Ceftaroline resistant isolates in our study probably suggest a hospital spread of Ceftaroline resistant MRSA emphasizing the need for stringent infection control precautions.

Effect of Ruta graveolens Extract on the Major Virulence Factors in Methicillin Resistant Staphylococcus aureus

Purpose

Rising Antibiotic Resistance has put the world in real threat. Methicillin resistant Staphylococcus aureus (MRSA), is a predominant cause of suppurative chronic skin and soft-tissue infections. Novel insights have focused the light on plant extracts. In this study, Ruta graveolens ethanolic active extract was tested for its potential anti-virulence activities in MRSA.

Materials and Methods

A total of 100 MRSA strains causing skin and soft tissue infections were isolated and antibiotic susceptibility testing was done. Ability to form biofilm was tested phenotypically. Furthermore, the antimicrobial activity of Ruta graveolens was evaluated followed by detection of its Minimum inhibitory concentration (MIC). The inhibitory activity of this extract on biofilm formation was investigated. Afterwards, we investigated its effect on the transcription of biofilm-related genes and mecA gene.

Results

All tested isolates were sensitive to Vancomycin and Linezolid while high resistance was noted with both Fusidic acid (83%) and Gentamicin (68%). (83%) of the isolates were biofilm producers. Ruta graveolens extract showed strong antimicrobial activity against the MRSA strains with MIC 0.78 mg/mL. At subinhibitory concentration (1/2 MIC), the extract had high biofilm inhibitory effects with mean inhibition (70%). Moreover, transcriptional analysis results showed that the mean percentages of inhibition in expression of mecA, icaA and icaD genes were 52.3%, 34.8% and 33.7%, respectively, in which all showed statistically significant difference (p ≤ 0.05).

Conclusion

The current study proposes the ability of Ruta graveolens extract to reduce the biofilm formation and antibiotic resistance of MRSA through downregulation of some biofilm forming genes and mecA gene which confers resistance to B-lactam antibiotics. This may decrease our reliance on antibiotics and improve our ability to effectively treat biofilm-related skin and soft-tissue infections caused by MRSA.

MRSA in the bursa: an unusual complication of MRSA bacteremia causing bilateral acromioclavicular septic arthritis

Background. Bacteraemia is known to cause serious complications including metastatic infections such as infective endocarditis, vertebral osteomyelitis, iliopsosas abscesses and septic arthritis. Bilateral septic arthritis, however, is a rare medical emergency with limited previous reports. Staphylococcus species are the most common organisms identified as a result of suspected haematogenous spread from bacteraemia, direct inoculation or translocation from adjacent tissues. While unilateral septic arthritis due to intravenous drug use is a common phenomenon warranting prompt treatment to preserve mobility, function and quality of life, cases of bilateral infections are exceedingly rare. Furthermore, infections involving the acromioclavicular joint are not commonly documented in the literature. Case Presentation. We present a case of a 41-year-old female with a history of intravenous drug use who presented with low back pain and was found to have methicillin-resistant Staphylococcus aureus bacteraemia that was complicated with metastatic infections causing bilateral acromioclavicular joint septic arthritis. Conclusions. Metastatic infections from bacteraemia are serious complications that can lead to septic arthritis. Though septic arthritis is best known in previous case reports to present as a unilateral infection, rare cases of bilateral involvement warrant further consideration. A thorough history and physical examination evaluating all joints can identify such atypical presentations. Septic arthritis remains a medical emergency, and it is imperative that clinicians recognize unusual presentations to avoid delays in treatment that can lead to detrimental impacts to quality of life.

Ceftaroline: Systematic Review of Clinical Uses and Emerging Drug Resistance

OBJECTIVE

To assess the success rates of off-label uses of ceftaroline for infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and evaluate emerging ceftaroline resistance.

DATA SOURCES

We queried PubMed/MEDLINE, with the search term "Ceftaroline." Articles were restricted to the English language and year of publication (January 1, 2009-January 31, 2022).

STUDY SELECTION AND DATA EXTRACTION

Clinical trials, observational studies, and case reports that reported efficacy, safety, pharmacokinetics, use in MRSA infections other than acute bacterial skin infection and community-acquired pneumonia, and ceftaroline resistance were selected.

DATA SYNTHESIS

The search pooled 103 publications and all abstracts were reviewed. Forty-six articles that reported efficacy, safety, pharmacokinetics, or off-label use in multiple patients and 7 articles on ceftaroline resistance are used in this review. Ceftaroline has been approved for treatment of acute skin/soft tissue infection and community-acquired pneumonia. Ceftaroline's efficacy in off-label infections ranged from 66.7% to 87.3% depending on the types of infection. There were 14 documented cases of ceftaroline resistance associated with PBP2a changes.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Case series and observational studies have documented success with ceftaroline alone or in combination with vancomycin or daptomycin for treatment of MRSA bone and joint, endovascular, diabetic foot infections, and bacteremia from other causes.

CONCLUSION

Despite the lack of randomized controlled trials, ceftaroline is used as salvage therapy for different MRSA infections. The data from case series and observational studies are promising but ceftaroline should be used judiciously as ceftaroline-resistant MRSA begin to emerge.

Evaluation of the synergistic effect of ceftaroline against methicillin-resistant Staphylococcus aureus

OBJECTIVES

We aimed to determine the synergistic effects of ceftaroline (CPT) in combination with daptomycin (DAP), vancomycin (VAN), or linezolid (LNZ) against various methicillin-resistant Staphylococcus aureus (MRSA) strains.

METHODS

MRSA strains randomly selected from 2014 to 2018 were studied. Checkerboard titration and in vitro time-kill analyses were used to determine the synergistic activities of the antibiotic combinations.

RESULTS

A total of 10 genetically distinct MRSA strains were included in this study. The checkerboard titration analysis revealed that the CPT-DAP, CPT-VAN, and CPT-LNZ combinations had a synergistic effect against 30%, 10%, and 10% of the selected MRSA strains, respectively. Using time-kill analysis, we showed that CPT-DAP exhibited a significant synergistic and sustained bactericidal effect against both DAP-susceptible (Δ colony-forming units/ml, -5.79; P = 0.0495) and DAP-resistant (Δ colony-forming units/ml, -6.40; P = 0.0463) MRSA strains at a concentration of 0.5 × the minimum inhibitory concentration of CPT plus 0.5 × the minimum inhibitory concentration of DAP. No synergistic bactericidal effects were observed for the CPT-VAN and CPT-LNZ combinations against the selected strains.

CONCLUSION

The CPT-DAP combination showed better synergistic activity than the CPT-VAN and CPT-LNZ combinations against the enrolled MRSA strains. DAP, rather than VAN or LNZ, might be a better choice for CPT combination in the treatment of MRSA 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.

Antibiotics for multidrug-resistant gram-positive bacteria

Background: Antimicrobial resistance is a major global threat to public health and is associated with increased morbidity and mortality. A few therapeutic options for the treatment of multidrug resistant (MDR) gram-positive bacteria, such as methicillin resistant Staphylococcus aureus, MDR Streptococcus pneumoniae, vancomycin resistant Enterococci, are available.Current Concepts: As a result of comprehensive efforts, a dozen novel antibiotics have been developed and approved for the treatment of MDR gram-positive bacteria in the United States and Europe over the past 15 years. However, only a few antibiotics have been introduced in the Republic of Korea. The purpose of this review is to evaluate the antibiotics that act against MDR gram-positive bacteria as a primary therapeutic option. Particularly, this review focuses on novel antibiotics, including ceftaroline, ceftobiprole, telavancin, dalbavancin, oritavancin, tedizolid, delafloxacin, omadacycline, and lefamulin.Discussion and Conclusion: Novel antibiotics against MDR gram-positive bacteria have not yet been sufficiently studied in various clinical settings, and therefore, the approved indications are limited. However, these antibiotics are expected to play a major role in the treatment of MDR gram-positive bacteria owing to their advantages, including broad anti-bacterial spectrum, rapid bactericidal effect, minimal drug-drug interaction, a favorable safety profile, availability of both intravenous and oral formulations, convenient dosing scheme, and a single dose (or once a week) regimen owing to long half-life. It is crucial to introduce these novel antibiotics in the Republic of Korea for the treatment of patients suffering from MDR bacterial infections.

Approaching 65 Years: Is it Time to Consider Retirement of Vancomycin for Treating Methicillin-Resistant Staphylococcus aureus Endovascular Infections?

Vancomycin was introduced nearly 65 years ago and remains the standard antibiotic for serious methicillin-resistant Staphylococcus aureus (MRSA) infections. Staphylococcus aureus remains highly susceptibility to vancomycin (>97%). Despite this, MRSA treatment failure with vancomycin is high in complicated bacteremia. Additionally, vancomycin can cause nephrotoxicity, leading to new therapeutic drug monitoring guidance. This demonstrates how difficult it is to dose vancomycin in a way that is both efficacious and safe, especially during long courses of therapy. Often underappreciated are the cost, resources, and complexity of vancomycin care at a time when alternative antibiotics are becoming cost comparable. This perspective highlights a bigger picture of how the treatment repertoires of many other diseases have changed and advanced since vancomycin’s introduction in the 1950s, yet the vancomycin MRSA treatment standard remains. While vancomycin can still have a role, 65 years may be a practical retirement age for vancomycin in highly complex endovascular infections.

Select controversies in the management of methicillin-resistant Staphylococcus aureus bacteremia: answers and remaining questions from recent evidence

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia continues to cause significant morbidity and mortality despite advances in medical therapy. Vancomycin therapy remains the standard of care for most cases of MRSA bacteremia but has pharmacokinetic and pharmacodynamic limitations, dosing complications, and known toxicity. Welcomed clinical trials have recently addressed some of the controversies that plague this field, including optimization of vancomycin dosing and use of combination therapy. In this review, we discuss these trials and their implications for clinical care and future research.

Plasma and Lung Tissue Pharmacokinetics of Ceftaroline Fosamil in Patients Undergoing Cardiac Surgery with Cardiopulmonary Bypass: an In Vivo Microdialysis Study

Ceftaroline fosamil, a fifth-generation cephalosporin antibiotic with activity against methicillin-resistant Staphylococcus aureus (MRSA), is currently approved for the treatment of pneumonia and complicated skin and soft tissue infections. However, pharmacokinetics data on free lung tissue concentrations in critical patient populations are lacking. The aim of this study was to evaluate the pharmacokinetics of the high-dose regimen of ceftaroline in plasma and lung tissue in cardiac surgery patients during intermittent and continuous administration. Nine patients undergoing elective cardiac surgery on cardiopulmonary bypass were included in this study and randomly assigned to intermittent or continuous administration. Eighteen hundred milligrams of ceftaroline fosamil was administered intravenously as either 600 mg over 2 h every 8 h (q8h) (intermittent group) or 600 mg over 2 h (loading dose) plus 1,200 mg over 22 h (continuous group). Interstitial lung tissue concentrations were measured by in vivo microdialysis. Relevant pharmacokinetics parameters were calculated for each group. Plasma exposure levels during intermittent and continuous administration were comparable to those of previously published studies and did not differ significantly between the two groups. In vivo microdialysis demonstrated reliable and adequate penetration of ceftaroline into lung tissue during intermittent and continuous administration. The steady-state area under the concentration-time curve from 0 to 8 h (AUCss 0-8) and the ratio of AUCSS 0-8 in lung tissue and AUC in plasma (AUClung/plasma) were descriptively higher in the continuous group. Continuous administration of ceftaroline fosamil achieved a significantly higher proportion of time for which the free drug concentration remained above 4 times the minimal inhibitory concentration (MIC) during the dosing interval (% fT>4xMIC) than intermittent administration for pathogens with a MIC of 1 mg/liter. Ceftaroline showed adequate penetration into interstitial lung tissue of critically ill patients undergoing major cardiothoracic surgery, supporting its use for pneumonia caused by susceptible pathogens.

Combination of ceftaroline and daptomycin as treatment for complicated osteomyelitis

Osteomyelitis is an infection involving bone. Staphylococcus aureus is the pathogen most frequently implicated; less frequently involved are other gram-positive organisms, such as Staphylococcus epidermidis, and also gram-negative organisms. The antibiotic of choice for treatment of osteomyelitis caused by methicillin-resistant staphylococci (MRS) is vancomycin, although other alternatives such as daptomycin or teicoplanin are also considered. Osteomyelitis caused by MRS can be difficult to treat safely and effectively. This case report describes the successful use of daptomycin combined with ceftaroline for the treatment of osteomyelitis caused by methicillin-resistant S. epidermidis (MRSE) in a 54-year-old woman, emphasising the clinical pharmacist's role in antimicrobial stewardship programmes. This alternative combination has been studied in the treatment of methicillin-resistant S. aureus (MRSA), but it may also be useful in MRSE.

Antimicrobial Stewardship: A Review for Internal Medicine Physicians

Antimicrobial stewardship is the need of the hour to prevent the collapse of our health care system at the hands of a pandemic of resistant pathogens. Inappropriate and indiscriminate abuse of antibiotics has left very few options for prescribing physicians as most of the pathogens, particularly gram-negative, are resistant to the major antibiotics. This article reviews the importance of Antimicrobial Stewardship Programs (ASP) for internal medicine physicians and residents. Commonly encountered clinical scenarios are discussed. Appropriate indications of antibiotics, pathogen-guided prescriptions, adverse effects of common antibiotics, and options to use newer antibiotics are reviewed. The role of a health care team is highlighted. The evidence-based steps taken to ensure ASPs implementation are reiterated to serve as an educational guide for medical residents and physicians.

What do beta-lactams add to vancomycin or daptomycin in the treatment of patients with methicillin-resistant Staphylococcus aureus bacteraemia? A review

Several studies have documented the synergy between vancomycin/daptomycin and various beta-lactams, and clinical studies have studied this combination therapy in humans. We review the published literature on this topic to know the utility of the combined treatment with beta-lactams in treating bacteraemia methicillin-resistant Staphylococcus aureus (MRSA) infections. Fifteen observational studies, three randomised clinical trials and three systematics reviews are analysed in this article. Observational studies used ceftaroline, cefazolin, piperacillin/tazobactam or cefepime among the beta-lactams. Clinical trials used cloxacillin or flucloxacillin as the most used beta-lactam in two trials and ceftaroline in one. Three systematic reviews are published. One of them only includes studies with vancomycin and included six studies. The other two systematic reviews include patients with daptomycin or vancomycin and included 15 and 9 studies, respectively. Adding a beta-lactam to vancomycin or daptomycin may help shorten bacteraemia and avoid recurrences in patients with MRSA bacteraemia. There is no evidence that combined therapy improves mortality. Nephrotoxicity in clinical trials precludes the use of combination therapy mainly with cloxacillin or flucloxacillin, but systematic reviews have not found a significant difference in this point in observational studies with other beta-lactams. The role of other beta-lactams such as ceftaroline should be thoroughly studied in these patients.

Ceftaroline vs vancomycin for the treatment of acute pulmonary exacerbations in pediatric patients with cystic fibrosis

INTRODUCTION

Respiratory infection with methicillin-resistant Staphylococcus aureus (MRSA) is an increasing complication in cystic fibrosis (CF) that results in accelerated lung function decline and mortality. Vancomycin is considered a first-line intravenous treatment agent for MRSA associated acute pulmonary exacerbations (APEs); however, rates of vancomycin intolerance and resistance have been observed. These factors have led to the exploration of additional treatment options for treating MRSA associated APEs.

METHODS

This is a retrospective chart review conducted at a CF center including patients 0 to 21 years of age with CF admitted for an APE and treated with either vancomycin or ceftaroline between January 2016 and August 2018. The primary endpoint was to determine ceftaroline efficacy compared to vancomycin in the treatment of MRSA associated APEs.

RESULTS

There were 180 patients included in the study with 90 patients in each antibiotic group. Admission to discharge forced expiratory volume in 1 second (FEV1 ) improved in the ceftaroline (66.5% vs 81.1%; P < .001) and vancomycin (65.5% vs 77.3%; P < .001) treatment groups. No difference existed in mean change in FEV1 (14.1% vs 13.5%; P = .25) or readmissions (15% vs 22; P = .27) between ceftaroline and vancomycin groups, respectively.

DISCUSSION

In this retrospective study, no difference existed between ceftaroline and vancomycin with regard to observed improvement in lung function from admission to discharge. Additionally, no difference was observed in mean FEV1 or readmission rate between the two groups. Ceftaroline may represent an effective and safe intravenous antimicrobial option for targeting MRSA in pediatric CF patients with APEs.

Differential effects of antibiotics on neutrophils exposed to lipoteichoic acid derived from Staphylococcus aureus

BACKGROUND

Persistent bacteremia occurs in at least 30% of patients with Staphylococcus aureus bloodstream infection (SAB) and may be attributable to a dysregulated host immune response. Neutrophils interact with a variety of S. aureus microbial factors, including lipoteichoic acid (LTA), to activate phagocytic function in a concentration-dependent manner. Antibiotics have been shown to exert both direct antimicrobial action as well as immunomodulatory effects. In this study, we compared the effects of different anti-staphylococcal antibiotics on LTA-mediated immune activation of neutrophils.

METHODS

Neutrophils obtained from healthy volunteers were exposed to two levels of LTA (1 and 10 μg/ml) with or without addition of antibiotics from different pharmacologic classes (vancomycin, daptomycin, ceftaroline). Neutrophil function was assessed by examining phagocytic response, activation (CD11b, CD62L expression), Toll-like receptor-2 expression, cell survival and apoptosis, and CXCL8 release.

RESULTS

Differential LTA-mediated antibiotic effects on neutrophil function were observed primarily at the high LTA exposure level. Ceftaroline in the presence of 10 μg/ml LTA had the most prominent effects on phagocytosis and CD11b and CD62L expression, with trends towards increased neutrophil survival and preservation of CXCL8 release when compared to daptomycin and vancomycin with the latter significantly dampening PMN CXCL8 release.

CONCLUSIONS

Select antimicrobial agents, such as ceftaroline, exert immunostimulatory effects on neutrophils exposed to S. aureus LTA, which when confirmed in vivo, could be leveraged for its dual immunomodulatory and antibacterial actions for the treatment of persistent SAB mediated by a dysregulated host response.

Antimicrobial Therapy in Septic Shock Is Conservative During Resuscitation and Maintenance Phases

Background: Maximal dosing of early antimicrobials with high loading and maintenance doses may optimize pharmacokinetic parameters to achieve and maintain therapeutic concentrations at the site of infection in septic shock. Little is known about the current practice of early antimicrobial dosing in septic shock. Objective: To characterize early antimicrobial dosing in patients in the resuscitation phase of septic shock. Methods: This retrospective cohort study included patients admitted to the medical intensive care unit (ICU) with septic shock. The primary outcome was the percentage of early antibiotic orders that were maximal or conservative during the resuscitation (0 to 48 hours) phase based on predefined dosing criteria. The secondary outcomes were the correlations of different dosing strategies on hospital length of stay (LOS), ICU LOS, and hospital mortality. Results: This study evaluated 161 patients and 692 antibiotic orders; 504 (72.8%) of the orders during the resuscitation phase were conservative. There were no differences in mortality (odds ratio = 0.66; 95% confidence interval = 0.35-1.25; P = .20), hospital LOS (median = 20 [interquartile range (IQR) = 10-34] vs 19 [IQR = 11-32] days; P = .93), or ICU LOS (median = 8 [IQR = 5-16] vs 9 [IQR = 5-15] days; P = .63) between maximal and conservative dosing groups, respectively, in the resuscitation phase. Limitations of this study included the use of institution-specific antimicrobial dosing guidelines and its retrospective nature. Conclusions: Early antibiotic dosing is conservative for a majority of patients in septic shock. Future studies are needed to evaluate the impact of dosing strategy on patient-centered outcomes in septic shock.

Quasiexperimental intervention study protocol to optimise the use of new antibiotics in Spain: the NEW_SAFE project

INTRODUCTION

Ceftaroline, tedizolid, dalbavancin, ceftazidime-avibactam and ceftolozane-tazobactam are novel antibiotics used to treat infections caused by multidrug-resistant pathogens (MDR). Their use should be supervised and monitored as part of an antimicrobial stewardship programme (ASP). Appropriate use of the new antibiotics will be improved by including consensual indications for their use in local antibiotic guidelines, together with educational interventions providing advice to prescribers to ensure that the recommendations are clearly understood.

METHODS AND ANALYSIS

This study will be implemented in two phases. First, a preliminary historical cohort (2017-2019) of patients from 13 Andalusian hospitals treated with novel antibiotics will be analysed. Second, a quasiexperimental intervention study will be developed with an interrupted time-series analysis (2020-2021). The intervention will consist of an educational interview between prescribers and ASP leaders at each hospital to reinforce the proper use of novel antibiotics. The educational intervention will be based on a consensus guideline designed and disseminated by leaders after the retrospective cohort data have been analysed. The outcomes will be acceptance of the intervention and appropriateness of prescription. Incidence of infection and colonisation with MDR organisms as well as incidence of Clostridioides difficile infection will also be analysed. Changes in prescription quality between periods and the safety profile of the antibiotics in terms of mortality rate and readmissions will also be measured.

ETHICS AND DISSEMINATION

Ethical approval will be obtained from the Andalusian Coordinating Institutional Review Board. The study is being conducted in compliance with the protocol and regulatory requirements consistent with International Council of Harmonisation E6 Good Clinical Practice and the ethical principles of the latest version of the Declaration of Helsinki. The results will be published in peer-reviewed journals and disseminated at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT03941951; Pre-results.

The rapid and visual detection of methicillin-susceptible and methicillin-resistant Staphylococcus aureus using multiplex loop-mediated isothermal amplification linked to a nanoparticle-based lateral flow biosensor

Background

Staphylococcus aureus (S. aureus), including methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA), is an eminent human pathogen that can colonize the human host and cause severe life-threatening infections. The development of a reliable, simple and rapid assay for detecting S. aureus and identifying MRSA is important for diagnosis and follow-up treatment.

Methods

A novel molecular diagnosis technique, named multiplex loop-mediated isothermal amplification linked to a nanoparticle-based lateral flow biosensor (m-LAMP-LFB), was applied to detect all S. aureus species and identify MRSA. Two sets of primers were designed based on the femA gene (S. aureus-specific gene) and the mecA gene (encoding penicillin-binding protein 2a), and the multiple-LAMP products were analyzed using LFB. The m-LAMP-LFB amplification conditions, including the target DNA concentration, reaction temperature and time, were optimized. The sensitivity and specificity of the m-LAMP-LFB method were tested in the current study, and the multiple-LAMP-LFB technology was applied to detect the MSSA and MRSA strains from clinical samples.

Results

The S. aureus- and MRSA-specific primers based on the femA and mecA genes allowed the multiple-LAMP technology to detect S. aureus and MRSA, respectively. The multiple-LAMP conditions were optimized at 63 °C for 40 min. The full process, including genomic DNA template preparation, LAMP, and product identification, could be achieved in 80 min. The limit of detection (LoD) of the multiple-LAMP assay for femA and mecA detection was 100 fg of genomic DNA template per reaction. The specificity of m-LAMP-LFB detection was 100 %, and no cross-reactions to non-S. aureus strains were observed.

Conclusion

The multiple-LAMP-LFB technique developed in the current study is a reliable, simple, rapid, specific and sensitive method to identify MSSA and MRSA infections for appropriate antibiotic therapy.

New cephalosporins for the treatment of pneumonia in internal medicine wards

The burden of hospital admission for pneumonia in internal medicine wards may not be underestimated; otherwise, cases of pneumonia are a frequent indication for antimicrobial prescriptions. Community- and hospital-acquired pneumonia are characterized by high healthcare costs, morbidity and non-negligible rates of fatality. The overcoming prevalence of resistant gram-negative and positive bacteria (e.g., methicillin-resistant Staphylococcus aureus, penicillin and ceftriaxone-resistant Streptococcus pneumoniae, extended-spectrum β-lactamases and carbapenemases producing Enterobacteriaceae) has made the most of the first-line agents ineffective for treating lower respiratory tract infections. A broad-spectrum of activity, favourable pulmonary penetration, harmlessness and avoiding in some cases a combination therapy, characterise new cephalosporins such as ceftolozane/tazobactam, ceftobiprole, ceftazidime/avibactam and ceftaroline. We aimed to summarise the role and place in therapy of new cephalosporins in community- and hospital-acquired pneumonia within the setting of internal medicine wards. The "universal pneumonia antibiotic strategy" is no longer acceptable for treating lung infections. Antimicrobial therapy should be individualized considering local antimicrobial resistance and epidemiology, the stage of the illness and potential host factors predisposing to a high risk for specific pathogens.

Emerging drugs for treating methicillin-resistant Staphylococcus aureus

Introduction: In clinical practice, methicillin-resistant Staphylococcus aureus (MRSA) represents a major threat and has been associated with high rates of inadequate antibiotic treatment and significant increases in morbidity, mortality, and overall healthcare costs. The association between the prescription of an inappropriate or delayed antibiotic and impaired clinical outcomes has been widely described. Areas covered: To address the threat of MRSA, many new therapeutic options with a peculiar activity against MRSA have been recently developed and approved. New agents are characterized by specific issues in terms of spectrum of activity, pharmacokinetics, risk of drug-drug interactions, and toxicity, with potential advantages that should be considered in everyday clinical practice. Expert opinion: The most attractive characteristic of new drugs is represented by the broad spectrum of activity against multidrug-resistant pathogens; moreover, new compounds in most cases are characterized by favorable toxicity profiles compared with old drugs currently used in clinical practice. Some of the new antimicrobials will be also available as oral formulations, with the potential for oral switch, even in infections due to resistant pathogens. In particular conditions/populations (e.g. liver failure, renal disease, pregnancy, diabetic, children, and elderly), novel antibiotics with reduced toxicity could be an important option, including after hospital discharge.

Multi-Drug-Resistant Organisms in Burn Infections

Background: Infection is the most frequent complication after severe burns and remains the predominant cause of death. Burn patients may require multiple courses of antibiotics, lengthy hospitalizations, and invasive procedures that place burn patients at especially high risk for infections with multi-drug-resistant organisms (MDROs). Methods: The published literature on MDROs in burn patients was reviewed to develop a strategy for managing these infections. Results: Within a burn unit meticulous infection prevention and control measures and effective antimicrobial stewardship can limit MDRO propagation and decrease the antibiotic pressure driving the selection of MDROs from less resistant strains. Several new antimicrobial agents have been developed offering potential therapeutic options, but familiarity with their benefits and limitations is required for safe utilization. Successful management of MDRO burn infections is supported by a multifactorial approach. Novel non-antibiotic therapeutics may help combat MDRO infections and outbreaks. Conclusions: Multi-drug-resistant organisms are being identified with increasing frequency in burn patients. Effective sensitivity testing is essential to identify MDROs and to direct appropriate antibiotic choices for patient treatment.

Methicillin-resistant Staphylococcus aureus replication in the presence of high (≥32 µg/ml) drug concentration of vancomycin as seen by electron microscopy

Methicillin-resistant Staphylococcus aureus (MRSA) has unfortunately become a common pathogen in many healthcare facilities. In many institutions, vancomycin remains the preferred agent for treating serious MRSA infections including bacteraemia with or without endocarditis. The mutant prevention concentration (MPC) testing ≥10⁹ colony forming units of bacteria, describes the antimicrobial drug concentration blocking the growth of the least susceptible cell from high density bacterial populations. With blood culture isolates of MRSA, we discovered strains with MPC values ≥32 µg/ml and viable cells could be readily recovered from agar plates containing 32 µg/ml of vancomycin. To investigate MRSA strains surviving in high concentrations of vancomycin on drug containing agar plates, we utilized electron microscopy to measure cell wall thickness as this has been previously reported as a potential mechanism of resistance¹ along with septum thickening. Our data shows MRSA replication from high density bacterial populations in the presence of ≥32 µg/ml of vancomycin. Such observations may explain vancomycin failure in some patients and/or persistent bacteraemia and could potentially question the use of this drug in some critically ill patients in favour of an alternative agent.

Ceftaroline-associated Encephalopathy in Patients With Severe Renal Impairment

Encephalopathy complicates beta-lactam therapy, particularly with impaired renal function, though no studies have reported ceftaroline-associated encephalopathy. Among 28 patients with estimated glomerular filtration rates <30 mL/min who received ≥5 days of ceftaroline, 3 developed encephalopathy. Ceftaroline, when dosed supra-therapeutically for serious infections, may be a cause of antibiotic-associated encephalopathy.

Comparing the Outcomes of Ceftaroline Plus Vancomycin or Daptomycin Combination Therapy Versus Monotherapy in Adults with Complicated and Prolonged Methicillin-Resistant Staphylococcus Aureus Bacteremia Initially Treated with Supplemental Ceftaroline

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia confers considerable morbidity and mortality. Although vancomycin or daptomycin monotherapy is usually curative, prolonged bacteremia necessitating supplemental ceftaroline has occurred. The practice has led to the question of whether to continue with ceftaroline following bacteremia resolution.

METHODS

Adult patients hospitalized with MRSA bacteremia at the University of Kentucky Medical Center between January 2015 and December 2017 were retrospectively reviewed. Study subjects required supplemental ceftaroline due to 4 or more days of bacteremia despite vancomycin or daptomycin. They additionally had accompanying native valve infective endocarditis, osteomyelitis, or brain abscess. Patients were divided into two cohorts. One group continued with ceftaroline plus vancomycin or daptomycin following bacteremia resolution (combination therapy group). The other group received vancomycin or daptomycin alone (monotherapy group). All involved received 6-8 weeks of therapy. Patients' Pitt bacteremia score (PBS) and Charlson comorbidity index (CCI) values were calculated. Treatment outcomes of inpatient mortality, recurrence of bacteremia, 30-day readmission, acute kidney injury, and leukopenia were recorded and compared.

RESULTS

A total of 30 patients comprised the study population. 15 patients were assigned to each cohort. The median PBS value of the combination therapy group was 2, compared with 1 among the monotherapy group. The median CCI score of both groups was 0. No statistically significant difference in the aforementioned treatment outcomes was seen between the two groups.

CONCLUSION

In subjects with complicated and prolonged MRSA bacteremia requiring supplemental ceftaroline, clinical outcomes did not differ among patients prescribed vancomycin or daptomycin alone following bacteremia resolution versus patients who continued combination therapy.

Newly Developed Prodrugs and Prodrugs in Development; an Insight of the Recent Years

BACKGROUND

The design and development of prodrugs is the most common and effective strategy to overcome pharmacokinetic and pharmacodynamic drawbacks of active drugs. A respected number of prodrugs have been reached the drugs market throughout history and the recent years have witnessed a significant increase in the use of prodrugs as a replacement of their parent drugs for an efficient treatment of various ailment.

METHODS

A Scan conducted to find recent approved prodrugs and prodrugs in development.

RESULTS

Selected prodrugs were reported and categorized in accordance to their target systems.

CONCLUSIONS

the prodrug approach has shown many successes and still remains a viable and effective approach to deliver new active agents. This conclusion is supported by the recent approved prodrugs and the scan of clinical trials conducted between 2013-2018.

Ceftriaxone- and ceftazidime-resistant Klebsiella species, Escherichia coli, and methicillin-resistant Staphylococcus aureus dominate caesarean surgical site infections at Mulago Hospital, Kampala, Uganda

Objectives:

The aim of this study was to determine the proportion and mechanism of resistance to ceftriaxone and ceftazidime among Klebsiella species and Escherichia coli and examine the burden of methicillin-resistant Staphylococcus aureus from caesarean section surgical site infections in Uganda.

Methods:

Wound swabs from 109 caesarean section surgical site infections were cultured for pathogenic bacteria following standard microbiological procedures. The Kirby–Bauer disc diffusion technique was used for antimicrobial susceptibility testing. Methicillin-resistant S. aureus diagnosis was based on polymerase chain reaction testing for the mecA gene. Data were analysed using SPSS-IBM Statistics v.20.

Results:

A total of 118 pathogens were recovered from 93 (85%) of 109 surgical site infections swabs. Of the 118 pathogens, gram-negative bacteria were 69 (58.5%), including 44 (37.3%) Klebsiella species, 11 (9.3%) E. coli, 6 (5.1%) Citrobacter species, and 8 (6.8%) other gram-negative bacteria. In total, 49 of the 118 pathogens were gram-positive bacteria, including 34 (28.8%) S. aureus and 15 (12.7%) Enterococci species. Resistance to ceftriaxone was detected in all 11 (100%) of the E. coli and in 43 (97.7%) of the 44 Klebsiella species and to ceftazidime in all 11 (100%) of the E. coli and 40 (91%) of the 44 Klebsiella species. Extended-spectrum beta-lactamase explained resistance to ceftazidime in 10 (91%) of the 11 E. coli and 19 (48%) of the 40 Klebsiella species. Carbapenemase production explained 15 (38%) of the 40 ceftazidime-resistant Klebsiella species. Methicillin-resistant S. aureus was detected in 91% of S. aureus.

Conclusion:

Klebsiella species, E. coli, and S. aureus–majority methicillin-resistant S. aureus dominated the pathogens in caesarean section surgical site infections. Almost all of the E. coli and Klebsiella species were resistant to ceftriaxone or ceftazidime. Extended-spectrum beta-lactamase was the underlying resistance mechanism among almost all of the ceftriaxone- or ceftazidime-resistant E. coli. However, this mechanism accounted for less than half of ceftriaxone- or ceftazidime-resistant Klebsiella species, where carbapenemases accounted for 40% of the resistance, a finding previously unreported in Uganda.

One Size Fits All? Application of Susceptible-Dose-Dependent Breakpoints to Pediatric Patients and Laboratory Reporting

The Clinical and Laboratory Standards Institute antimicrobial and antifungal standards define a susceptible-dose-dependent (SDD) category for certain organisms and drug combinations. Reporting MICs within the SDD category suggests that treatment success is likely with increased drug exposure. These breakpoints are based on pharmacokinetic, pharmacodynamic, and clinical outcome data from adults and not pediatric patients. This commentary aims to discuss the implications of reporting SDD interpretations for pediatric patients and recommends laboratory reporting comments.

[Position statement of the Spanish Association of Paediatrics-Spanish Society of Paediatric Infectious Diseases (AEP-SEIP) on the treatment of multidrug-resistant bacterial infections]

A progressive increase in the incidence of infections caused by multidrug-resistant microorganisms is being reported. Among these resistant microorganisms, the main threats are extended-spectrum β-lactamase-, AmpC-, and carbapenemase-producing Gram-negative bacilli, methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium. To address this important problem, it is essential to establish pediatric Antimicrobial Stewardship programs, perform active epidemiological surveillance and develop an adequate infection control policy. The therapeutic approach of these infections is often complex, frequently requiring antibiotics with less experience in children. In this position document made by the Spanish Association of Pediatrics and the Spanish Society of Pediatric Infectious Diseases, the epidemiology and treatment of these infections are reviewed according to the best available evidence.

Important new therapies for methicillin-resistant Staphylococcus aureus

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) infections represent a leading cause of infection-related morbidity and mortality worldwide. There has been a welcome increase in the number of agents available for the treatment of MRSA infection over the last decade and several clinical trials are currently investigating the role of new experimental strategies.Areas covered: The purpose of this manuscript is to review the efficacy and safety of recently approved anti-MRSA molecules as well as some newer agents currently under investigation with a specific focus on the potential role of these drugs in everyday clinical practice.Expert opinion: Many new drugs with an activity against MRSA have been recently approved or are in an advanced stage of development. All these compounds represent promising options to enhance our antibiotic armamentarium. However, data regarding the use of these new compounds in real-life terms are limited and their best placement in therapy and in terms of optimization of medical resources and balance of cost-effectiveness requires further investigation.