Ceftaroline activity against Staphylococcus aureus isolated from patients with infective endocarditis, worldwide (2010-2019)

Clonal shift and impact of azithromycin use on antimicrobial resistance of Staphylococcus aureus isolated from bloodstream infection during the COVID-19 pandemic

Staphylococcus aureus is a relevant pathogen in bloodstream infections (BSI), and the emergency of the COVID-19 pandemic increased its antimicrobial resistance. S. aureus isolates from BSI (September/2019 - March/2021) were analyzed phenotypically and molecularly, in addition to the clinical features of the patients. Of 88 S. aureus isolates recovered from 85 patients, 25 were isolated before the pandemic and 63 during it, and 16 were from patients with COVID-19. A rate of 45.5% of methicillin-resistant isolates (MRSA) were found, and 5% of them were ceftaroline susceptible dose-dependent. Daptomycin non-susceptibility was observed in 9.1% of isolates. The USA800/ST5/SCCmecIV lineage was prevalent among MRSA isolates (41.8%). Besides, 30.2% of the isolates were associated with community-associated MRSA (CA-MRSA) genotypes. There was a significant impact on the resistance rates for cefoxitin, clindamycin and erythromycin among S. aureus isolates from BSI in COVID-19 patients and association with the previous use of azithromycin by them (p < 0.05). A clonal alternation and an increase in the emergence of CA-MRSA lineages were also found, highlighting the importance of constant microbiological surveillance.

New advances in management and treatment of cardiac implantable electronic devices infections

Cardiac implantable electronic devices (CIED) are increasingly used worldwide, and infection of these devices remains one of the most feared complications.CIED infections (CDIs) represent a challenge for physicians and the healthcare system in general as they require prolonged hospitalization and antibiotic treatment and are burdened by high mortality and high costs, so management of CDIs must be multidisciplinary.The exact incidence of CDIs is difficult to define, considering that it is influenced by various factors mainly represented by the implanted device and the type of procedure. Risk factors for CDIs could be divided into three categories: device related, patient related, and procedural related and the etiology is mainly sustained by Gram-positive bacteria; however, other etiologies cannot be underestimated. As a matter of fact, the two cornerstones in the treatment of these infections are device removal and antimicrobial treatment. Finally, therapeutic drug monitoring and PK/PD correlations should be encouraged in all patients with CDIs receiving antibiotic therapy and may result in a better clinical outcome and a reduction in antibiotic resistance and economic costs.In this narrative review, we look at what is new in the management of these difficult-to-treat infections.

In vitro Activity of Ceftaroline Against Isolates of Gram-Positive Bacteria from Patients with Bloodstream Infections Collected as a Part of ATLAS Between 2017 and 2020

Purpose

To assess the in vitro activity of ceftaroline and a panel of comparator agents against isolates of Gram-positive bacteria, including Staphylococcus aureus, Streptococcus pneumoniae, β-hemolytic streptococci, and coagulase-negative staphylococci (CoNS) from blood collected in Africa and Middle East (AfME), Asia Pacific (APAC), Europe, Latin America (LATAM), and North America from 2017 to 2020 as a part of the Antimicrobial Testing Leadership and Surveillance (ATLAS) program.

Methods

Susceptibility and minimum inhibitory concentration were determined using broth microdilution for all antimicrobial agents by a central reference laboratory according to the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines.

Results

Ceftaroline showed good activity (susceptibility ≥89.8%, MIC90 0.008-2 mg/L) against all Gram-positive isolates tested. All isolates of methicillin-susceptible S. aureus, penicillin-susceptible S. pneumoniae, S. agalactiae, S. dysgalactiae, and S. pyogenes were susceptible to ceftaroline (MIC90 0.008-0.25 mg/L). Ceftaroline susceptibility for MRSA isolates was 89.8% globally (MIC90 2 mg/L). Among the comparator agents, all isolates were susceptible to vancomycin, except S. epidermis (susceptibility, 99.9%). Among other agents, daptomycin, linezolid, and tigecycline showed potent activity (susceptibility ≥97.9%, MIC90 0.03-2 mg/L) against all isolates tested.

Conclusion

Ceftaroline showed potent in vitro activity against global bloodstream isolates of Gram-positive bacteria collected between 2017 and 2020. Monitoring and surveillance of global as well as regional longitudinal trends of resistance rates among Gram-positive isolates causing bloodstream infections are important to limit the spread of AMR, establish stewardship measures, and manage and appropriately treat infections.

Off-label use versus formal recommendations of conventional and novel antibiotics for the treatment of infections caused by multidrug-resistant bacteria

The infections caused by multidrug- and extensively drug-resistant (MDR, XDR) bacteria, including Gram-positive cocci (GPC, including methicillin-resistant Staphylococcus aureus, MDR-Streptococcus pneumoniae and vancomycin-resistant enterococci) and Gram-negative bacilli (GNB, including carbapenem-resistant [CR] Enterobacterales, CR-Pseudomonas aeruginosa and XDR/CR-Acinetobacter baumannii complex) can be quite challenging for physicians with respect to treatment decisions. Apart from complicated urinary tract and intra-abdominal infections (cUTIs, cIAIs), bloodstream infections and pneumonia, these difficult-to-treat bacteria also cause infections at miscellaneous sites (bones, joints, native/prosthetic valves and skin structures, etc.). Antibiotics like dalbavancin, oritavancin, telavancin and daptomycin are currently approved for the treatment of acute bacterial skin and skin structural infections (ABSSSIs) caused by GPC. Additionally, ceftaroline, linezolid and tigecycline have been formally approved for the treatment of community-acquired pneumonia and ABSSSI. Cefiderocol and meropenem-vaborbactam are currently approved for the treatment of cUTIs caused by XDR-GNB. The spectra of ceftazidime-avibactam and imipenem/cilastatin-relebactam are broader than that of ceftolozane-tazobactam, but these three antibiotics are currently approved for the treatment of hospital-acquired pneumonia, cIAIs and cUTIs caused by MDR-GNB. Clinical investigations of other novel antibiotics (including cefepime-zidebactam, aztreonam-avibactam and sulbactam-durlobactam) for the treatment of various infections are ongoing. Nevertheless, evidence for adequate antibiotic regimens against osteomyelitis, arthritis and infective endocarditis due to several GPC and MDR-GNB is still mostly lacking. A comprehensive review of PubMed publications was undertaken and the formal indications and off-label use of important conventional and novel antibiotics against MDR/XDR-GPC and GNB isolates cultured from miscellaneous sites are presented in this paper.

Quantification of Ceftaroline in Human Plasma Using High-Performance Liquid Chromatography with Ultraviolet Detection: Application to Pharmacokinetic Studies

This study was conducted to develop a rapid, simple and reproducible method for the quantification of ceftaroline in plasma samples by high-performance liquid chromatography with ultraviolet detection (HPLC-UV). Sample processing consisted of methanol precipitation and then, after centrifugation, the supernatant was injected into the HPLC system, working in isocratic mode. Ceftaroline was detected at 238 nm at a short acquisition time (less than 5 min). The calibration curve was linear over the concentration range from 0.25 to 40 µg/mL, and the method appeared to be selective, precise and accurate. Ceftaroline in plasma samples was stable at -80 °C for at least 3 months. The method was successfully applied to characterize the pharmacokinetic profile of ceftaroline in two critically ill patients and to evaluate whether the pharmacokinetic/pharmacodynamic (PK/PD) target was reached or not with the dose regimen administered.