Besifloxacin Ophthalmic Suspension 0.6% Compared with Gatifloxacin Ophthalmic Solution 0.3% for the Treatment of Bacterial Conjunctivitis in Neonates

Antibiotic resistance of bacterial pathogens isolated from the conjunctiva in the Antibiotic Resistance Monitoring in Ocular micRoorganisms (ARMOR) surveillance study (2009-2021)

Antibiotic resistance in bacterial ocular infections is of significant clinical concern and may affect treatment outcomes. We report on in vitro antibiotic susceptibility rates and trends among conjunctival-sourced isolates collected in the Antibiotic Resistance Monitoring in Ocular micRoorganisms (ARMOR) surveillance study. A total of 2214 conjunctival isolates (918 Staphylococcus aureus, 589 coagulase-negative staphylococci [CoNS], 194 Streptococcus pneumoniae, 171 Pseudomonas aeruginosa, and 342 Haemophilus influenzae) obtained between 2009-2021 were analyzed. Staphylococci were commonly resistant to azithromycin (≥54.8%) and oxacillin (≥29.3%). Resistance among S. pneumoniae isolates was notable for azithromycin (34.0%) and penicillin (28.9%), while P. aeruginosa and H. influenzae isolates were highly susceptible to most tested antibiotics. Methicillin-resistant staphylococci demonstrated greater concurrent resistance to other antibiotics than methicillin-susceptible isolates and exhibited high rates of multidrug resistance (≥74.0%). Among staphylococci, antibiotic resistance increased with patient age, and there were small decreases in resistance to several drugs over the 13-year period. These findings indicate that resistance to antibiotics routinely used in ophthalmic practice remains high among conjunctival isolates.

Neonatal Conjunctivitis

Neonatal conjunctivitis is an important cause of ocular morbidity with infectious and noninfectious origins. Common practice in the United States is to administer prophylactic antibiotic ointment at birth; however, prophylaxis is ineffective for some causes. Moreover, recognition of the etiologies that threaten systemic complications to the neonate is critical in providing timely and appropriate treatment. This review summarizes the clinical features, etiology, and treatment recommendations of various forms of neonatal conjunctivitis.

Safety of Quinolones in Children: A Systematic Review and Meta-Analysis

BACKGROUND

The results of animal experiments show that quinolone antibacterial drugs may permanently damage the soft tissues of the weight-bearing joints of young animals. Out of safety concerns, using quinolones in children has always been controversial.

OBJECTIVE

The aim of this study was to assess the risk of using quinolones in children and provide evidence for clinicians to support decision making.

DATA SOURCES

The MEDLINE (Ovid), EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), International Pharmaceutical Abstracts (Ovid), CINAHL, CNKI, VIP, and WanFang Data databases were searched from inception to 8 September 2021.

STUDY SELECTION

All types of studies that reported the safety data of quinolones in children, including clinical trials and observational studies.

DATA EXTRACTION

Data extraction and cross-checking were completed by two independent reviewers using a pilot-tested standardized data extraction form.

RESULTS

The overall incidence rate of adverse drug events (ADEs) in children using systemic quinolones was 5.39% and the most common ADEs were gastrointestinal reactions (incidence rate, 2.02%). Quinolone-induced musculoskeletal ADEs in children were uncommon (0.76%). Meta-analysis results showed that the risk of musculoskeletal ADEs in children using quinolones was higher than children in the control group (51 studies; rate ratio [RR] 2.03, 95% confidence interval [CI] 1.82-2.26; p < 0.001; I² = 18.6%; moderate-quality evidence). However, the subgroup analysis results showed that differences might only be observed in children who were followed up for 2 months to 1 year (2-6 months: RR 2.56, 95% CI 2.26-2.89; 7 months to 1 year: RR 1.35, 95% CI 0.98-1.86). Moreover, children (adolescents) aged between 13 and 18 years might be sensitive to the musculoskeletal toxicity of quinolones (RR 2.69, 95% CI 2.37-3.05; moderate-quality evidence) and the risk of levofloxacin-induced musculoskeletal ADEs might be higher (RR 1.33, 95% CI 1.00-1.77; low-quality evidence).

CONCLUSIONS

Although the existing evidence shows that quinolone-induced musculoskeletal ADEs seem to be only short-term and reversible, and no serious skeletal and muscular system damage cases have been reported in children, quinolones should be avoided unless necessary in children because the incidence rate of quinolone-related ADEs is not low and they are broad-spectrum antibiotics that will induce the emergence of resistant strains if used frequently.

Practical Guidance for Clinical Microbiology Laboratories: Diagnosis of Ocular Infections

The variety and complexity of ocular infections have increased significantly in the last decade since the publication of Cumitech 13B, Laboratory Diagnosis of Ocular Infections (L. D. Gray, P. H. Gilligan, and W. C. Fowler, Cumitech 13B, Laboratory Diagnosis of Ocular Infections, 2010). The purpose of this practical guidance document is to review, for individuals working in clinical microbiology laboratories, current tools used in the laboratory diagnosis of ocular infections. This document begins by describing the complex, delicate anatomy of the eye, which often leads to limitations in specimen quantity, requiring a close working bond between laboratorians and ophthalmologists to ensure high-quality diagnostic care. Descriptions are provided of common ocular infections in developed nations and neglected ocular infections seen in developing nations. Subsequently, preanalytic, analytic, and postanalytic aspects of laboratory diagnosis and antimicrobial susceptibility testing are explored in depth.

In Vitro Time-Kill of Common Ocular Pathogens with Besifloxacin Alone and in Combination with Benzalkonium Chloride

BACKGROUND

Besifloxacin ophthalmic suspension 0.6% (w/v%) contains benzalkonium chloride (BAK) as a preservative. We evaluated the in vitro time-kill activity of besifloxacin, alone and in combination with BAK, against common bacteria implicated in ophthalmic infections.

METHODS

The activity of besifloxacin (100 µg/mL), BAK (10, 15, 20, and 100 µg/mL), and combinations of besifloxacin and BAK were evaluated against isolates of Staphylococcus epidermidis (n = 4), Staphylococcus aureus (n = 3), Haemophilus influenzae (n = 2), and Pseudomonas aeruginosa (n = 2) in time-kill experiments of 180 min duration. With the exception of one S. aureus isolate, all of the staphylococcal isolates were methicillin- and/or ciprofloxacin-resistant; one P. aeruginosa isolate was ciprofloxacin-resistant. The reductions in the viable colony counts (log₁₀ CFU/mL) were plotted against time, and the differences among the time-kill curves were evaluated using an analysis of variance. Areas-under-the-killing-curve (AUKCs) were also computed.

RESULTS

Besifloxacin alone demonstrated ≥3-log killing of P. aeruginosa (<5 min) and H. influenzae (<120 min), and approached 3-log kills of S. aureus. BAK alone demonstrated concentration-dependent killing of S. epidermidis, S. aureus and H. influenzae, and at 100 µg/mL produced ≥3-log kills in <5 min against these species. The addition of BAK (10, 15, and 20 µg/mL) to besifloxacin increased the rate of killing compared to besifloxacin alone, with earlier 3-log kills of all species except P. aeruginosa and a variable impact on S. aureus. The greatest reductions in AUKC were observed among H. influenzae (8-fold) and S. epidermidis (≥5-fold). Similar results were found when the isolates were evaluated individually by their resistance phenotype.

CONCLUSIONS

In addition to confirming the activity of 100 µg/mL BAK as a preservative in the bottle, these data suggest that BAK may help besifloxacin to achieve faster time-kills on-eye in the immediate timeframe post-instillation before extensive dilution against bacterial species implicated in ophthalmic infections, including drug-resistant S. epidermidis. Greater killing activity may help prevent resistance development and/or help treat resistant organisms.

Design, Synthesis, and Biological Evaluation of Membrane-Active Bakuchiol Derivatives as Effective Broad-Spectrum Antibacterial Agents

Infections caused by drug-resistant bacteria seriously endanger human health and global public health. Therefore, it is urgent to discover and develop novel antimicrobial agents to combat multidrug-resistant bacteria. In this study, we designed and synthesized a series of new membrane-active bakuchiol derivatives by biomimicking the structure and function of cationic antibacterial peptides. The most promising compound 28 displayed potent antibacterial activity against both Gram-positive bacteria (minimum inhibitory concentration, MIC = 1.56-3.125 μg/mL) and Gram-negative bacteria (MIC = 3.125 μg/mL), very weak hemolytic activity, and low cytotoxicity. Compound 28 had rapid bactericidal properties and avoided bacterial resistance. More importantly, compound 28 showed strong in vivo antibacterial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa in murine corneal infection models. This design strategy is expected to provide an effective solution to the antibiotic crisis.

Antimicrobial resistance of ocular microbes and the role of antimicrobial peptides

Isolation of antimicrobial-resistant microbes from ocular infections may be becoming more frequent. Infections caused by these microbes can be difficult to treat and lead to poor outcomes. However, new therapies are being developed which may help improve clinical outcomes. This review examines recent reports on the isolation of antibiotic-resistant microbes from ocular infections. In addition, an overview of the development of some new antibiotic therapies is given. The recent literature regarding antibiotic use and resistance, isolation of antibiotic-resistant microbes from ocular infections and the development of potential new antibiotics that can be used to treat these infections was reviewed. Ocular microbial infections are a global public health issue as they can result in vision loss which compromises quality of life. Approximately 70 per cent of ocular infections are caused by bacteria including Chlamydia trachomatis, Staphylococcus aureus, and Pseudomonas aeruginosa and fungi such as Candida albicans, Aspergillus spp. and Fusarium spp. Resistance to first-line antibiotics such as fluoroquinolones and azoles has increased, with resistance of S. aureus isolates from the USA to fluoroquinolones reaching 32 per cent of isolates and 35 per cent being methicillin-resistant (MRSA). Lower levels of MRSA (seven per cent) were isolated by an Australian study. Antimicrobial peptides, which are broad-spectrum alternatives to antibiotics, have been tested as possible new drugs. Several have shown promise in animal models of keratitis, especially treating P. aeruginosa, S. aureus or C. albicans infections. Reports of increasing resistance of ocular isolates to mainstay antibiotics are a concern, and there is evidence that for ocular surface disease this resistance translates into worse clinical outcomes. New antibiotics are being developed, but not by large pharmaceutical companies and mostly in university research laboratories and smaller biotech companies. Antimicrobial peptides show promise in treating keratitis.

Treating with besifloxacin for acute bacterial conjunctivitis: a Meta-analysis

AIM

To evaluate the relative efficacy and safety of besifloxacin for treatment of acute bacterial conjunctivitis.

METHODS

A comprehensive search in PubMed, EMBASE Web of Science, Cochrane Central Database and CNKI was undertaken for randomized controlled trials (RCTs) comparing besifloxacin with other treatments or placebo. The primary outcome measures were clinical resolution, rates of bacterial eradication, individual clinical outcomes, cure rates, and bacterial eradication rates of different kinds of pathogens. Safety outcomes were the number of adverse effects (AEs). The final search was performed on August 2018.

RESULTS

Six RCTs were included. Four studies compared the efficacy and safety of besifloxacin with placebo, 1 study compared besifloxacin with moxifloxacin, and 1 study compared besifloxacin with gatifloxacin. A total of 2780 patients met the inclusion criteria. Besifloxacin presented higher efficacy and safety than did placebo in clinical resolution, rates of bacterial eradication, individual clinical outcomes, cure rates, bacterial eradication rates of different kinds of pathogens and the number of AEs. There was no significant difference between besifloxacin and moxifloxacin or gatifloxacin in the comparison items mentioned above.

CONCLUSION

Besifloxacin is highly effective and safe for treatment of acute bacterial conjunctivitis. Further comparative trials regarding the effect of besifloxacin for treatment of acute bacterial conjunctivitis will aid in treatment decisions.

Novel Antibiotics for Multidrug-Resistant Gram-Positive Microorganisms

Increasing multidrug-resistance to Gram-positive pathogens, particularly to staphylococci, enterococci and streptococci, is a major problem, resulting in significant morbidity, mortality and healthcare costs. In recent years, only a small number of novel antibiotics effective against Gram-positive bacteria has been approved. This review will discuss the current evidence for novel branded antibiotics that are highly effective in the treatment of multidrug-resistant infections by Gram-positive pathogens, namely ceftobiprole, ceftaroline, telavancin, oritavancin, dalbavancin, tedizolid, besifloxacin, delafloxacin, ozenoxacin, and omadacycline. The mechanism of action, pharmacokinetics, microbiological spectrum, efficacy and safety profile will be concisely presented. As for any emerging antibiotic agent, resistance is likely to develop against these highly effective antibiotics. Only through appropriate dosing, utilization and careful resistance development monitoring will these novel antibiotics continue to treat Gram-positive pathogens in the future.