The growing emergence of antimicrobial resistance represents a global problem that not only influences healthcare systems but also has grave implications for political and economic processes. As the discovery of novel antimicrobial agents is lagging, one of the solutions is innovative therapeutic options that would expand our armamentarium against this hazard. Compounds of interest in many such studies are antimicrobial peptides (AMPs), which actually represent the host’s first line of defense against pathogens and are involved in innate immunity. They have a broad range of antimicrobial activity against Gram-negative and Gram-positive bacteria, fungi, and viruses, with specific mechanisms of action utilized by different AMPs. Coupled with a lower propensity for resistance development, it is becoming clear that AMPs can be seen as emerging and very promising candidates for more pervasive usage in the treatment of infectious diseases. However, their use in quotidian clinical practice is not without challenges. In this review, we aimed to summarize state-of-the-art evidence on the structure and mechanisms of action of AMPs, as well as to provide detailed information on their antimicrobial activity. We also aimed to present contemporary evidence of clinical trials and application of AMPs and highlight their use beyond infectious diseases and potential challenges that may arise with their increasing availability.

Radioactivity is a process in which the nuclei of unstable atoms spontaneously decay, producing other nuclei and releasing energy in the form of ionizing radiation in the form of alpha (α) and beta (β) particles as well as the emission of gamma (γ) electromagnetic waves. People may be exposed to radiation in various forms, as casualties of nuclear accidents, workers in power plants, or while working and using different radiation sources in medicine and health care. Acute radiation syndrome (ARS) occurs in subjects exposed to a very high dose of radiation in a very short period of time. Each form of radiation has a unique pathophysiological effect. Unfortunately, higher organisms—human beings—in the course of evolution have not acquired receptors for the direct “capture” of radiation energy, which is transferred at the level of DNA, cells, tissues, and organs. Radiation in biological systems depends on the amount of absorbed energy and its spatial distribution, particularly depending on the linear energy transfer (LET). Photon radiation with low LET leads to homogeneous energy deposition in the entire tissue volume. On the other hand, radiation with a high LET produces a fast Bragg peak, which generates a low input dose, whereby the penetration depth into the tissue increases with the radiation energy. The consequences are mutations, apoptosis, the development of cancer, and cell death. The most sensitive cells are those that divide intensively—bone marrow cells, digestive tract cells, reproductive cells, and skin cells. The health care system and the public should raise awareness of the consequences of ionizing radiation. Therefore, our aim is to identify the consequences of ARS taking into account radiation damage to the respiratory system, nervous system, hematopoietic system, gastrointestinal tract, and skin.

Legionella pneumophila is defined as a bacterium that can cause severe pneumonia. It is found in the natural environment and in water, and is often found in water tanks. It can be an integral part of biofilms in nature, and the protozoa in which it can live provide it with food and protect it from harmful influences; therefore, it has the ability to move into a sustainable but uncultured state (VBNC). L. pneumophila has been shown to cause infections in dental practices. The most common transmission route is aerosol generated in dental office water systems, which can negatively affect patients and healthcare professionals. The most common way of becoming infected with L. pneumophila in a dental office is through water from dental instruments, and the dental unit. In addition to these bacteria, patients and the dental team may be exposed to other harmful bacteria and viruses. Therefore, it is vital that the dental team regularly maintains and decontaminates the dental unit, and sterilizes all accessories that come with it. In addition, regular water control in dental offices is necessary.

Rationale: Herpes simplex virus 1 establishes a latent infection in trigeminal ganglia. Reactivation causes cold sores, as well as viral keratitis. The purpose of this study was to report potential benefits of using active vitamin D receptor ligands (VDR-agonists) as adjunctive therapies for the treatment of infectious corneal perforations, and prevention of HSV recurrence. Patient concerns: A 57-year-old female with a past history of episodic, poorly-healing, corneal erosions, recurring orolabial herpetic lesions, as well as PCR-confirmed recurrences of herpes simplex keratitis presented with a burning sensation and slight pain in the right eye. Examination indicated HSV keratitis. Topical antibiotic and oral antiviral treatments were prescribed. Despite these standard-of-care treatments, a perforated corneal ulcer ensued. Diagnoses: Corneal perforation associated with HSV-1 keratitis recurrence, later confirmed by PCR analysis of corneal scrapings. Interventions: Corneal perforation was treated with a human fibrin glue, fortified with multilayered amniotic membrane transplant, as well as a therapeutical contact lens. Following surgery, calcifediol and paricalcitol were started as oral adjunctive therapies in an attempt to boost tissue regeneration and innate-immunity within the slow-healing cornea. Anterior segment optical-coherence tomography was used to measure corneal thickness. Frequent follow-ups with various specialists allowed for comprehensive patient evaluation, and meticulous screening for any signs indicating potential HSV-1 recurrence. Outcomes: Following calcifediol-paricalcitol therapy corneal thickening, and re-epithelization ensued. During combined calcifediol-paricalcitol therapy, the patient has had no recurrence of herpes simplex keratitis, or orolabial herpes lesions. Lessons: Corneal stabilization avoided a high-risk, full-thickness corneal transplantation, facilitating future cataract surgery, and allowing for some degree of visual recovery in this eye. Export

Background and Clinical Significance: Acanthamoeba keratitis (AK) is a rare but serious corneal infection that can lead to severe visual impairment or blindness if not promptly treated. The condition is primarily associated with contact lens use but can also occur due to ocular trauma or environmental contamination. The most frequently used treatment options include biguanides and diamidines, though dosing protocols remain empirical and vary widely among clinicians. Recent research has explored a new standardized protocol with 0.08% polihexanide (polyhexamethylene biguanide, PHMB) as a monotherapy for AK, offering improved efficacy and better corneal penetration. Case Presentation: This case report describes a 35-year-old female contact lens wearer who presented with redness, pain, photophobia, and vision loss in her right eye. Upon referral, a slit-lamp examination revealed stromal infiltrates and perineural involvement, with in vivo confocal microscopy (IVCM) confirming Acanthamoeba cysts. The patient was treated with a new standardized intensive regimen of polihexanide 0.08% monotherapy, leading to rapid clinical improvement. Corneal infiltrates were significantly reduced, and the best-corrected visual acuity (BCVA) improved from 0.4 logMAR to 0.15 logMAR. Resolution with only discrete stromal haze was achieved over the following months, without recurrence. Conclusions: This case highlights the potential of polihexanide 0.08% monotherapy as an effective treatment for AK in a new standardized treatment protocol.