Surveillance of iclaprim activity: in vitro susceptibility of Gram-positive skin infection pathogens collected from 2015 to 2016 from North America and Europe

Antistaphylococcal discovery pipeline; where are we now?

The serious spread of antibiotic-resistant Staphylococcal aureus strains is alarming. This is reflected by the measures governments and health-related bodies are offering to ease antibiotic drug development. Finding new active agents, preferably with novel mechanism of action, or even finding new targets for drug development are essential. In this review, we summarize the current status of novel antistaphylococcal agents undergoing clinical trials. We mainly discuss antistaphylococcal small molecules and peptides in the text with a special focus on their chemistry, while antistaphylococcal immunotherapy (antibodies) are mentioned in a summative table. This review shall serve as a summary that influences future synthetic efforts in the antistaphyloccocals development field.

Methicillin Resistant Staphylococcus aureus: Molecular Mechanisms Underlying Drug Resistance Development and Novel Strategies to Combat

Antimicrobial resistance (AMR) represents a major threat to global health. Infection caused by Methicillin-resistant Staphylococcus aureus (MRSA) is one of the well-recognized global public health problem globally. In some regions, as many as 90% of S. aureus infections are reported to be MRSA, which cannot be treated with standard antibiotics. WHO reports indicated that MRSA is circulating in every province worldwide, significantly increasing the risk of death by 64% compared to drug-sensitive forms of the infection which is attributed to its antibiotic resistance. The emergence and spread of antibiotic-resistant MRSA strains have contributed to its increased prevalence in both healthcare and community settings. The resistance of S. aureus to methicillin is due to expression of penicillin-binding protein 2a (PBP2a), which renders it impervious to the action of β-lactam antibiotics including methicillin. The other is through the production of beta-lactamases. Although the treatment options for MRSA are limited, there are promising alternatives to antibiotics to combat the infections. Innovative therapeutic strategies with wide range of activity and modes of action are yet to be explored. The review highlights the global challenges posed by MRSA, elucidates the mechanisms underlying its resistance development, and explores mitigation strategies. Furthermore, it focuses on alternative therapies such as bacteriophages, immunotherapy, nanobiotics, and antimicrobial peptides, emphasizing their synergistic effects and efficacy against MRSA. By examining these alternative approaches, this review provides insights into the potential strategies for tackling MRSA infections and combatting the escalating threat of AMR. Ultimately, a multifaceted approach encompassing both conventional and novel interventions is imperative to mitigate the impact of MRSA and ensure a sustainable future for global healthcare.

Efficacy and Safety of Iclaprim for the Treatment of Skin Structures and Soft Tissue Infections: A Methodological Framework

Background: Skin and soft tissue infections (SSTIs) are among the most common infections worldwide. They manifest in a variety of forms, such as erysipelas, cellulitis, and necrotizing fasciitis. Antibiotics are the significant method for clinical treatment of SSTIs. This study reported a methodology framework to determine the efficacy and safety of iclaprim in treatment of SSTIs.

Methods: We will search the PubMed, EMbase, CNKI, WanFang Data, VIP, and ClinicalTrials.gov from their inception to June 2022 for randomized controlled trials and cohort studies on iclaprim with SSTIs. Two authors will independently screen the eligible studies, assess the quality of the included papers, and extract the required information. Randomized controlled trials will be assessed using the Cochrane risk-of-bias tool. The Newcastle–Ottawa Scale will be used to evaluate observational studies. The quality of the evidence will be evaluated using the Grading of Recommendations Assessment Development and Evaluation system. RevMan 5.3 will be used for the data synthesis and quantitative analysis.

Results and Discussions: This study will provide the clinicians with more high-quality evidence to choose iclaprim for patients with SSTIs.

Ethics and Dissemination: This systematic review and meta-analysis will be based on published data, so ethical approval is not necessary. The results of this meta-analysis will be published in a peer-reviewed journal.

In vitro activity of ceftaroline and comparators against bacterial isolates collected globally from patients with skin infections

OBJECTIVES

This study reports the antimicrobial activities of ceftaroline and comparators against bacterial isolates from patients with skin and skin-structure infections (2015-2018).

METHODS

A central laboratory performed antimicrobial susceptibility testing according to CLSI broth microdilution methodology. EUCAST breakpoints were used.

RESULTS

Isolates were collected in Europe (14 408 isolates; 53.9%), Asia/South Pacific (SP) (5317; 19.9%), Latin America (4268; 16.0%) and Africa/Middle East (ME) (2753; 10.3%). In all regions, all 7950 methicillin-susceptible Staphylococcus aureus (MSSA) isolates were susceptible to ceftaroline and vancomycin; susceptibility to daptomycin, linezolid, teicoplanin and tigecycline was ≥99.6%. Susceptibility of all 9174 methicillin-resistant S. aureus (MRSA) isolates to daptomycin, linezolid, teicoplanin, tigecycline and vancomycin was ≥97.7%, with 90.8-96.5% susceptible to ceftaroline. The ceftaroline MIC90 was 0.008 mg/L against Streptococcus pyogenes, 0.015-0.03 mg/L against Streptococcus agalactiae and 0.008-0.015 mg/L against Streptococcus dysgalactiae. All β-haemolytic streptococci were susceptible to vancomycin. Susceptibility of extended-spectrum β-lactamase (ESBL)-negative Escherichia coli to ceftaroline ranged from 67.0% in Asia/SP to 91.0% in Africa/ME; susceptibility to amikacin, meropenem and tigecycline was ≥96.7% in all regions. Susceptibility of ESBL-negative Klebsiella pneumoniae to ceftaroline ranged from 78.4% in Europe to 83.2% in Africa/ME, and among ESBL-negative Klebsiella oxytoca was 76.3% in Asia/SP and 89.0-93.5% in other regions. Among ESBL-negative K. pneumoniae and ESBL-negative K. oxytoca, susceptibility was highest to amikacin (93.7-96.4% and 95.7-100%, respectively) and meropenem (89.7-97.4% and 98.3-100%, respectively).

CONCLUSION

Ceftaroline was active against the Gram-positive isolates collected. Susceptibility of ESBL-negative Gram-negative isolates showed regional variations.

Investigating the efficacy and safety of mineral smectite granules on wound healing

Mineral smectite granules have traditionally been used for diarrhea and gastrointestinal bleeding; however, the wound healing ability of mineral smectite granules has not been investigated in detail. Therefore, the present study explored the efficacy and safety of mineral smectite granules on wound healing. An excision wound rat model was established. The experimental group was treated with smectite granules, the positive control group was treated with starch and the blank control group was left untreated. Wound closure rates, wound healing times and histopathological analysis were compared among the three groups. The mechanism underlying the effects of mineral smectite granules on wound healing was assessed by performing picrosirius red staining and immunohistochemical staining and measuring hydroxyproline content. Based on wound closure rates, wound healing times and histopathological analysis, the results indicated that rats treated with smectite granules displayed increased wound healing efficacy compared with the other two groups. Investigation of the underlying mechanism suggested that mineral smectite granules could promote wound healing by inducing collagen fiber synthesis and increasing the number of neovessels. The present study indicated the efficacy and safety of mineral smectite granules on wound healing and provided a theoretical basis for its application in a clinical setting.

Iclaprim reduces the incidence and severity of Staphylococcus aureus-induced septic arthritis in a murine model

Staphylococcus aureus is the most common non-gonococcal aetiology of septic arthritis. The efficacy of iclaprim against S. aureus LS-1, a clinical strain identified from a patient with septic arthritis, was studied in MF1 mice to evaluate the activity of iclaprim, which is in clinical development, in preventing joint infections. Iclaprim (2.5–80 mg kg⁻¹) administered as a single dose via the tail vein reduced the incidence of S. aureus septic arthritis and mortality in an experimental murine model of septic arthritis.

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.

Worldwide surveillance of Iclaprim activity: In Vitro susceptibility of gram-positive pathogens collected from patients with skin and skin structure infections from 2013 to 2017

Iclaprim is a novel diaminopyrimidine, which inhibits bacterial dihydrofolate reductase, and it is active against Gram-positive pathogens including emerging drug-resistant pathogens. In vitro activity of iclaprim and comparators against 1365 Gram-positive clinical isolates from patients with skin and skin structure infections (SSSI) from the United States, Asia Pacific, Latin America, Europe, Africa or Middle East collected between 2013 and 2017 were tested. Susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Minimum inhibitory concentration (MIC) interpretations were based on CLSI criteria. MIC₉₀ for all S.aureus, methicillin-susceptible S. aureus, methicillin-resistant S. aureus, Streptococcus pyogenes, S. agalactiae, S. anginosus, S. constellatus, S. dysgalactiae and S. intermedius were 0.12, 0.12, 0.5, 0.03, 0.5, ≤0.004, ≤0.004, 0.12, and 0.008 μg/ml, respectively. The MIC for iclaprim was 8 to 32-fold lower than trimethoprim, the only FDA approved dihydrofolate reductase inhibitor, against all Gram-positive isolates including resistant phenotypes. Iclaprim demonstrated lower MICs than trimethoprim against a collection (2013-2017) of Gram-positive clinical isolates from patients with SSSI from the United States, Asia Pacific, Latin America, and Europe.

Pharmacotherapy of Lower Respiratory Tract Infections in Elderly-Focused on Antibiotics

Lower respiratory tract infections (LRTIs) refer to the inflammation of the trachea, bronchi, bronchioles, and lung tissue. Old people have an increased risk of developing LRTIs compared to young adults. The prevalence of LRTIs in the elderly population is not only related to underlying diseases and aging itself, but also to a variety of clinical issues, such as history of hospitalization, previous antibacterial therapy, mechanical ventilation, antibiotic resistance. These factors mentioned above have led to an increase in the prevalence and mortality of LRTIs in the elderly, and new medical strategies targeting LRTIs in this population are urgently needed. After a systematic review of the current randomized controlled trials and related studies, we recommend novel pharmacotherapies that demonstrate advantages for the management of LRTIs in people over the age of 65. We also briefly reviewed current medications for respiratory communicable diseases in the elderly. Various sources of information were used to ensure all relevant studies were included. We searched Pubmed, MEDLINE (OvidSP), EMBASE (OvidSP), and ClinicalTrials.gov. Strengths and limitations of these drugs were evaluated based on whether they have novelty of mechanism, favorable pharmacokinetic/pharmacodynamic profiles, avoidance of interactions and intolerance, simplicity of dosing, and their ability to cope with challenges which was mainly evaluated by the primary and secondary endpoints. The purpose of this review is to recommend the most promising antibiotics for treatment of LRTIs in the elderly (both in hospital and in the outpatient setting) based on the existing results of clinical studies with the novel antibiotics, and to briefly review current medications for respiratory communicable diseases in the elderly, aiming to a better management of LRTIs in clinical practice.

In Vitro Activity of Iclaprim against Isolates in Two Phase 3 Clinical Trials (REVIVE-1 and -2) for Acute Bacterial Skin and Skin Structure Infections

Iclaprim, a selective bacterial dihydrofolate reductase inhibitor, and other antibiotics were tested against Gram-positive isolates from two phase 3 studies of acute bacterial skin and skin structure infections (ABSSSIs) (REVIVE-1 and -2). Seven hundred ninety baseline isolates, including Staphylococcus aureus, β-hemolytic streptococci, and Streptococcus anginosus group, underwent antibacterial susceptibility testing. Iclaprim had an MIC₉₀ of 0.12 μg/ml for S. aureus (0.12 μg/ml for methicillin susceptible, 0.25 μg/ml for methicillin resistant), 0.25 μg/ml for β-hemolytic streptococci, and 0.008 μg/ml for S. anginosus group. Iclaprim demonstrated potent activity against these Gram-positive ABSSSI isolates.