Staphylococcus: Infecciones y Patologías de la Piel

• These are study notes about staphylococcus and conditions related to it

Piel (Skin)

• The skin's microbiota includes Staphylococcus epidermidis, Corynebacterium sp., Propionibacterium sp., Streptococcus sp., y Enterobacteriaceae
• Microbiota does not exist in subcutaneous cellular tissue, muscle, and bone.
• Other microbes in the skin include Peptococcus, Peptostreptococcus, Micobacterium, and Cándida.

Patógenos (Pathogens)

• Staphylococcus Aureus causes infection
• Clostridium such as perfringens, novyi, septicum, tetani, histolyticum causes infection
• Micobacterium Leprae causes infection
• Examples of viral pathogens include Herpes types I, II, III (varicela-zoster), Papiloma, Papoviridae, Poxvirus, and Sarampión (measles).
• Examples of fungal pathogens include Microsporum, Trichophyton, Epidermophyton, Cándida, Esporotrix, and Micetoma.

Staphylococcus

• Causes pathologies such as Impetigo, furunculosis, cellulitis, abscesses, anthrax, and newborn pemphigus.
• Scalded skin syndrome is also caused by this.
• Impetigo presents as a papule with skin maceration, and regional adenitis.
• Pemphigus causes elevations of 2 to 3 cm that contain amber or yellow liquid, later forming an erythematous crust.

Más patologías (more pathologies)

• Can cause digestive issues like enteritis, peritonitis, liver abscess, and food poisoning.
• Genitourinary pathologies such as cystitis, prostatitis, nephritis, urethritis, and vaginitis
• Respiratory pathologies like sinusitis, pharyngitis, otitis, pneumonitis and pulmonary or pleural abscesses
• Other pathologies include meningoencephalitis, arthritis, myositis, myocarditis, conjunctivitis, septicemia, and osteomyelitis.
• Mechanisms of transmission are direct contact, ingestion of contaminated foods (Toxin - Bacteria), inhalation, and parenteral route.
• They are gram-positive cocci of 1 to 2 µm in diameter, grouped in clusters, facultative aerobes and anaerobes, immobile, do not form a capsule, and do not form spores.
• In recent decades, they have developed significant antibiotic resistance.

Identificación (Identifying)

• Cultivation media include blood agar, chocolate agar, nutrient agar, BHI (brain-heart infusion) agar, and Chapman 110 medium.
• Grows at 37°C forming white colonies or with a yellowish tint, rounded, convex, or with a smooth surface.
• Widely distributed in the environment and can be isolated from any part of the skin and some mucous membranes.
• Frequently present in food, it produces important pathologies, inflammation of any tissue with pus formation.
• Includes Coagulase test, Carbohydrates, Gelatin, and Anti Staphylococcus antibodies.

Factores de patogenicidad (Pathogenicity Factors)

• Include: Adhesin, coagulase, lipase, hyaluronidase, nuclease, fibrinolysin, exfoliatin, Pyrogenic toxins A, B, C, and Enterotoxins: A, B, C1, C2, D, E, and F.
• Hemolysins alpha are factors because they form "pores" in the membrane capable of altering ionic exchange, producing lysis of erythrocytes, leukocytes, platelets, and hepatocytes by osmotic alteration.
• Hemolysins beta are factors because (sphingomyelinase C) hydrolyzes the phospholipids of the erythrocyte membrane, macrophages, and fibroblasts.

Antígenos y Tratamiento (Antigens and Treatment)

• Antigens found in Staphylococcus aureus = polysaccharide A
• Antigens found in Staphylococcus epidermidis = polysaccharide B
• Staphylococcus aureus has antigens that are: Chemotactic, mitogenic, anticomplementary, antiphagocytic, antiplatelet, NK lymphocyte activator
• For treatment: MSSA (methicillin-sensitive S. aureus): penicillinase-resistant penicillins
• For treatment: MRSA (methicillin-resistant S. aureus): vancomycin