[Therapy-resistant sores of the lower extremities]

Herpes simplex type 1 (HSV‑1) is a widespread pathogen responsible for orolabial lesions. It is an enveloped, double-stranded DNA (dsDNA) virus belonging to the family Herpesviridae. Once the virus infects a host cell, its double‑stranded DNA genome is delivered into the nucleus, where a coordinated cascade of immediate‑early, early, and late gene expression directs viral DNA replication, structural protein synthesis, and virion assembly. After primary infection of epithelial cells, HSV-1...

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...

Cancer is the second leading cause of death in the United States. A cancer cell is genetically unstable and hence can mutate faster. They can also modify their microenvironment and escape immune surveillance. The difficulties in treating cancer are further compounded by the emergence of rapid resistance to anticancer drugs. The most common ways to attain resistance in cancer cells include alteration in drug transport and metabolism, modification of drug target, elevated DNA damage response, or...

Genital herpes is a sexually transmitted infection primarily caused by herpes simplex virus type 2 (HSV-2), though herpes simplex virus type 1 (HSV-1) is increasingly implicated in genital infections, particularly among younger populations. Transmission occurs mainly through sexual contact, with asymptomatic viral shedding serving as a major route of spread. This characteristic makes HSV-2 difficult to control at a population level, as individuals may unknowingly transmit the virus even in the...

Definition A diabetic foot ulcer (DFU) is a chronic, non-healing wound that develops in individuals with diabetes. It typically occurs on pressure-bearing areas such as the heel, metatarsal heads, or hallux, and carries a high risk of infection and amputation.Pathophysiology • The development of DFUs can be explained by four interconnected mechanisms: neuropathy, ischemia, infection, and impaired wound healing. • Neuropathy is the most common factor. Sensory neuropathy reduces pain perception,...

Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...