Alternative Treatment Strategies for Secondary Bacterial and Fungal Infections Associated with COVID-19

Nanoformulations Insights: A Novel Paradigm for Antifungal Therapies and Future Perspectives

Currently, fungal infections are becoming more prevalent worldwide. Subsequently, many antifungal agents are available to cure diseases like pemphigus, athlete's foot, acne, psoriasis, hyperpigmentation, albinism, and skin cancer. Still, they fall short due to pitfalls in physiochemical properties. Conventional medications like lotion, creams, ointments, poultices, and gels are available for antifungal therapy but present many shortcomings. They are associated with drug retention and poor penetration problems, resulting in drug resistance, hypersensitivity, and diminished efficacy. On the contrary, nanoformulations have gained tremendous potential in overcoming the drawbacks of conventional delivery. Furthermore, the potential breakthroughs of nanoformulations are site-specific targeting. It has improved bioavailability, patient-tailored approach, reduced drug retention and hypersensitivity, and improved skin penetration. Nowadays, nanoformulations are gaining popularity for antifungal therapy against superficial skin infections. Nanoformulations-based liposomes, niosomes, nanosponges, solid lipid nanoparticles, and potential applications have been explored for antifungal therapy due to enhanced activity and reduced toxicity. Researchers are now more focused on developing patient-oriented target-based nano delivery to cover the lacunas of conventional treatment with higher immune stimulatory effects. Future direction involves the construction of novel nanotherapeutic devices, nanorobotics, and robust methods. In addition, for the preparations of nanoformulations for clinical studies, animal modeling solves the problems of antifungal therapy. This review describes insights into various superficial fungal skin infections and their potential applications, nanocarrier-based drug delivery, and mechanism of action. In addition, it focuses on regulatory considerations, pharmacokinetic and pharmacodynamic studies, clinical trials, patents, challenges, and future inputs for researchers to improve antifungal therapy.

Beyond antibiotics: phage-encoded lysins against Gram-negative pathogens

Antibiotics remain the frontline agents for treating deadly bacterial pathogens. However, the indiscriminate use of these valuable agents has led to an alarming rise in AMR. The antibiotic pipeline is insufficient to tackle the AMR threat, especially with respect to the WHO critical category of priority Gram-negative pathogens, which have become a serious problem as nosocomial and community infections and pose a threat globally. The AMR pandemic requires solutions that provide novel antibacterial agents that are not only effective but against which bacteria are less likely to gain resistance. In this regard, natural or engineered phage-encoded lysins (enzybiotics) armed with numerous features represent an attractive alternative to the currently available antibiotics. Several lysins have exhibited promising efficacy and safety against Gram-positive pathogens, with some in late stages of clinical development and some commercially available. However, in the case of Gram-negative bacteria, the outer membrane acts as a formidable barrier; hence, lysins are often used in combination with OMPs or engineered to overcome the outer membrane barrier. In this review, we have briefly explained AMR and the initiatives taken by different organizations globally to tackle the AMR threat at different levels. We bring forth the promising potential and challenges of lysins, focusing on the WHO critical category of priority Gram-negative bacteria and lysins under investigation for these pathogens, along with the challenges associated with developing them as therapeutics within the existing regulatory framework.

Xuanfei Baidu decoction in the treatment of coronavirus disease 2019 (COVID-19): Efficacy and potential mechanisms

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide and become a major global public health concern. Although novel investigational COVID-19 antiviral candidates such as the Pfizer agent PAXLOVID™, molnupiravir, baricitinib, remdesivir, and favipiravir are currently used to treat patients with COVID-19, there is still a critical need for the development of additional treatments, as the recommended therapeutic options are frequently ineffective against SARS-CoV-2. The efficacy and safety of vaccines remain uncertain, particularly with the emergence of several variants. All 10 versions of the National Health Commission's diagnosis and treatment guidelines for COVID-19 recommend using traditional Chinese medicine. Xuanfei Baidu Decoction (XFBD) is one of the "three Chinese medicines and three Chinese prescriptions" recommended for COVID-19. This review summarizes the clinical evidence and potential mechanisms of action of XFBD for COVID-19 treatment. With XFBD, patients with COVID-19 experience improved clinical symptoms, shorter hospital stay, prevention of the progression of their symptoms from mild to moderate and severe symptoms, and reduced mortality in critically ill patients. The mechanisms of action may be associated with its direct antiviral, anti-inflammatory, immunomodulatory, antioxidative, and antimicrobial properties. High-quality clinical and experimental studies are needed to further explore the clinical efficacy and underlying mechanisms of XFBD in COVID-19 treatment.

A 71-Year-Old Man From Ecuador With a History of Type 2 Diabetes Mellitus and Severe COVID-19 Pneumonia and Lung Cavitation Associated With Triple Infection With Trichosporon Asahii, Klebsiella Pneumoniae, and Pseudomonas Aeruginosa

Unvaccinated patients with comorbidities that impair the immune function, such as type 2 diabetes mellitus, are more likely to develop severe COVID-19. The COVID-19-associated acute respiratory distress syndrome has raised new concerns in intensive care units globally owing to the presence of secondary fungal infections. We report the case of a 71-year-old man from Ecuador with a history of type 2 diabetes mellitus, severe COVID-19 pneumonia, and lung cavitation associated with triple infections with Trichosporon asahii, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The patient with a history of high blood pressure and type 2 diabetes was admitted to our hospital from a private care center with a diagnosis of COVID-19-associated acute respiratory distress syndrome. On arrival, the patient presented with signs of hypoxemic respiratory failure. During his stay at another hospital, he had received tocilizumab and corticosteroid therapy. Therefore, intubation was performed and mechanical ventilation was initiated. The patient developed a septic shock and renal failure with a glomerular filtration rate of 27.5 mL/min/1.73 m2; therefore, two hemodiafiltration sessions were started. The bronchoalveolar lavage revealed erythematous lesions in the bronchial tree and abundant purulent secretions and erosions in the bronchial mucosa, with a cavitary lesion in the right bronchial tree. The bronchoalveolar lavage samples were used to isolate Trichosporon asahii, Klebsiella pneumoniae, and Pseudomonas aeruginosa carbapenemase class A. Matrix-assisted laser desorption/ionization–time of flight (MALDI-TOF) Biotyper mass spectrometry and polymerase chain reaction (PCR) molecular identification were performed. This case report suggested that patients with severe COVID-19 pneumonia, with or without comorbidities, are more susceptible to opportunistic infections.