Bacterial Infections MCQs

Staphylococcal Scalded Skin Syndrome, also known as Ritter disease is a disease characterized by denudation of the skin caused by exotoxin producing strains of the Staphylococcus species, typically from a distant site. Also called as pemphigus neonatorum. Reference: Rooks textbook of Dermatology, 9 th Edition, Chapter 50, page 27

Characterized by a painful bright red appearance of the involved skin, which forms a sharply demarcated plaque. Involve upper dermal lymphatics. Classic cause: group A streptococci.

Staphylococcus aureus is the most common pathogen of folliculitis and furuncles. Gram-negative pathogens including Klebsiella , Enterobacter , and Proteus species may replace the gram-positive flora on facial skin, nasal mucous membranes, and neighbouring areas, causing gram-negative folliculitis and boils. 'Hot tub' folliculitis is caused by Pseudomonas aeruginosa contamination of undertreated water in saunas or whirlpools.

It has a non-fluorinated quinolone, antibiotic, showing potent antimicrobial activities against Gram-negative and Gram-positive bacteria. Ozenoxacin inhibit the enzymes DNA gyrase and topoisomerase IV, involved in the DNA synthesis in bacteria. Approved in to treat non-bullous impetigo in adults and children aged ≥6 months. Also used in treatment of acne

Streptococcus pyogenes (group A Streptococcus ) is one of the most important bacterial causes of skin and soft tissue infections worldwide. Specifically, this organism causes infections in the superficial epidermis (Non-Bullous Impetigo), the dermal lymphatics (erysipelas), the subcutaneous tissue (cellulitis), the fascia (necrotizing fasciitis), or muscle (myositis and myonecrosis). It is also the etiologic agent of scarlet fever and Streptococcal Toxic Shock Syndrome (StrepTSS). Bullous impetigo - caused by staphylococcus aureus

Impetigo is the most common bacterial skin infection in children and manifests as thin, superficial vesiculopustular which soon rupture to form a honey colored crusts.

Mupirocin belongs to the topical antibiotic class of medications and is utilized for managing and treating various skin and soft tissue infections Mupirocin is believed to exert its antimicrobial activity by inhibiting isoleucyl-transfer RNA, thereby obstructing bacterial protein and RNA synthesis, ultimately resulting in cell death. Mupirocin is recognized as the most widely used topical antibiotic globally for treating methicillin-resistant Staphylococcus aureus (MRSA), particularly in cases of impetigo Mupirocin has consistently demonstrated its efficacy in eradicating intranasal MRSA colonization in healthcare settings

This patient is probably suffering from bacterial vaginosis, as she has typical foul smelling watery discharge, pH greater 4.5, and positive whiff test. Wet mount/gram stain of discharge Bacterial vaginosis can be diagnosed in this case as she meets three out of four Amsel criteria. The first-line treatment for bacterial vaginosis is metronidazole. REFERENCE: IADVL textbook of dermatology, 4 th edition chapter 4