Bacterial Diseases

Q: What is Staphylococcus aureus skin infection?

A: A bacterial skin infection caused by Gram-positive cocci .

Q: How is Staphylococcus aureus skin infection acquired?

A: Through direct contact or entry via hair follicles; often from nasal carriers.

Q: What does Staphylococcus aureus skin infection cause?

A: Pus-filled lesions such as folliculitis, styes, boils, and carbuncles.

Q: What are the major virulence factors of Staphylococcus aureus skin infection?

A: Coagulase, leukocidin, superantigen toxins, and antibiotic resistance (MRSA).

Q: Who is at risk for Staphylococcus aureus skin infection?

A: Anyone; hospital personnel carriers.

Q: What are the key prevention and treatment principles for Staphylococcus aureus skin infection?

A: Hygiene, wound care, and antibiotics; MRSA requires specific agents.

Q: What is Impetigo?

A: A superficial skin infection caused by S. aureus or S. pyogenes or both.

Q: How is Impetigo acquired?

A: Direct contact with lesions or contaminated surfaces; highly contagious.

Q: What does Impetigo cause?

A: Vesicles that rupture into honey-colored crusted lesions.

Q: What are the major virulence factors of Impetigo?

A: Exfoliative toxins (S. aureus), M protein and enzymes (S. pyogenes).

Q: Who is at risk for Impetigo?

A: Children, especially in crowded environments.

Q: What are the key prevention and treatment principles for Impetigo?

A: Hygiene and topical/oral antibiotics.

Q: What is Scalded Skin Syndrome?

A: A toxin-induced skin condition caused by S. aureus.

Q: How is Scalded Skin Syndrome acquired?

A: Through S. aureus strains producing exfoliative toxins.

Q: What does Scalded Skin Syndrome cause?

A: Bullous impetigo at site of infection, redness, and widespread exfoliation.

Q: What are the major virulence factors of Scalded Skin Syndrome?

A: Exfoliative toxins ETA and ETB.

Q: Who is at risk for Scalded Skin Syndrome?

A: Infants and young children.

Q: What are the key prevention and treatment principles for Scalded Skin Syndrome?

A: IV antibiotics and supportive care.

Q: What is Toxic Shock Syndrome?

A: A toxin-mediated acute condition caused by S. aureus.

Q: How is Toxic Shock Syndrome acquired?

A: Toxin release from tampon use, wounds, or surgical sites.

Q: What does Toxic Shock Syndrome cause?

A: Fever, rash, low blood pressure, and multi-organ failure.

Q: What are the major virulence factors of Toxic Shock Syndrome?

A: TSST-1 superantigen toxin.

Q: Who is at risk for Toxic Shock Syndrome?

A: Tampon users and patients with wound infections.

Q: What are the key prevention and treatment principles for Toxic Shock Syndrome?

A: Remove source, IV fluids, and antibiotics.

Q: What is Streptococcus pyogenes skin infection?

A: A skin infection caused by Group A Streptococcus (GAS).

Q: How is Streptococcus pyogenes skin infection acquired?

A: Through breaks in skin or via respiratory droplets.

Q: What does Streptococcus pyogenes skin infection cause?

A: Impetigo, erysipelas, cellulitis, necrotizing fasciitis, strep throat, scarlet fever etc.

Q: What are the major virulence factors of Streptococcus pyogenes skin infection?

A: M protein, hemolysins, capsule, hyaluronidase, streptolysins, streptokinase, DNases.

Q: Who is at risk for Streptococcus pyogenes skin infection?

A: Anyone, especially people with skin trauma.

Q: What are the key prevention and treatment principles for Streptococcus pyogenes skin infection?

A: Penicillin and wound care.

Q: What is Acne caused by Cutibacterium acnes?

A: A chronic inflammation of hair follicles due to C. acnes overgrowth.

Q: How is Acne caused by Cutibacterium acnes acquired?

A: Blocked follicles and excess sebum encourage bacterial growth.

Q: What does Acne caused by Cutibacterium acnes cause?

A: Pimples, nodules, cysts, tissue destruction, scarring, and inflammation.

Q: What are the major virulence factors of Acne caused by Cutibacterium acnes?

A: Enzymes and inflammatory metabolites.

Q: Who is at risk for Acne caused by Cutibacterium acnes?

A: Teenagers and those with oily skin.

Q: What are the key prevention and treatment principles for Acne caused by Cutibacterium acnes?

A: Topicals, retinoids, and antibiotics.

Q: What is Pseudomonas dermatitis?

A: A skin infection caused by Gram-negative Pseudomonas aeruginosa.

Q: How is Pseudomonas dermatitis acquired?

A: Exposure to contaminated water, such as hot tubs.

Q: What does Pseudomonas dermatitis cause?

A: Hot-tub rash, folliculitis, and burn wound infections.

Q: What are the major virulence factors of Pseudomonas dermatitis?

A: Exotoxins, endotoxin, and biofilms.

Q: Who is at risk for Pseudomonas dermatitis?

A: Swimmers and burn patients.

Q: What are the key prevention and treatment principles for Pseudomonas dermatitis?

A: Water sanitation and specialized antibiotics.

Q: What is Bacterial conjunctivitis “Pink Eye”?

A: Infection of conjunctiva by bacteria such as Staph, Strep, H. influenzae, or Pseudomonas.

Q: How is Bacterial conjunctivitis acquired?

A: Direct contact with infected secretions or contaminated surfaces.

Q: What does Bacterial conjunctivitis cause?

A: Redness, irritation, purulent discharge.

Q: What are the major virulence factors of Bacterial conjunctivitis?

A: Pili, enzymes, and toxins depending on the pathogen.

Q: Who is at risk for Bacterial conjunctivitis?

A: Children and close-contact groups.

Q: What are the key prevention and treatment principles for Bacterial conjunctivitis?

A: antibiotic eye drops or ointments.

Q: What is Ophthalmia neonatorum?

A: Severe neonatal conjunctivitis caused by N. gonorrhoeae or C. trachomatis.

Q: How is Ophthalmia neonatorum acquired?

A: Vertical transmission during vaginal birth.

Q: What does Ophthalmia neonatorum cause?

A: Eye swelling, discharge, and blindness if untreated.

Q: What are the major virulence factors of Ophthalmia neonatorum?

A: Gonococcal endotoxin and Chlamydia intracellular survival.

Q: Who is at risk for Ophthalmia neonatorum?

A: Newborns born to infected mothers.

Q: What are the key prevention and treatment principles for Ophthalmia neonatorum?

A: Antibiotics.

Q: What is Trachoma?

A: A chronic conjunctival infection caused by Chlamydia trachomatis.

Q: How is Trachoma acquired?

A: Direct contact, contaminated fomites, and flies.

Q: What does Trachoma cause?

A: Eyelash inversion (trichiasis), corneal scarring, blindness.

Q: What are the major virulence factors of Trachoma?

A: Chlamydial plasmid and bacterial proteins.

Q: Who is at risk for Trachoma?

A: People living in poor sanitation areas and no access to healthcare.

Q: What are the key prevention and treatment principles for Trachoma?

A: Antibiotics and hygiene improvements.

Q: What is Urinary Tract Infection?

A: Infection of the urinary tract, most commonly by E. coli.

Q: How is Urinary Tract Infection acquired?

A: Ascending infection from urethra; often from GI flora.

Q: What does Urinary Tract Infection cause?

A: Dysuria, frequency, urgency, and suprapubic pain.

Q: What are the major virulence factors of Urinary Tract Infection pathogens?

A: Adhesins (P fimbriae), LPS, motility.

Q: Who is at risk for Urinary Tract Infection?

A: Women, catheterized patients (nosocomial infections).

Q: What are the key prevention and treatment principles for Urinary Tract Infection?

A: Hydration and antibiotics.

Q: What is Bacterial vaginitis?

A: A disruption of vaginal microbiota dominated by Gardnerella vaginalis.

Q: How is Bacterial vaginitis acquired?

A: Imbalance of vaginal flora, not an STI.

Q: What does Bacterial vaginitis cause?

A: Thin gray discharge with fishy odor; clue cells.

Q: What are the major virulence factors of Bacterial vaginitis?

A: Biofilm formation.

Q: Who is at risk for Bacterial vaginitis?

A: Sexually active women.

Q: What are the key prevention and treatment principles for Bacterial vaginitis?

A: Antibiotics and hygiene.

Q: What is Gonorrhea?

A: An STI caused by Gram-negative diplococcus N. gonorrhoeae.

Q: How is Gonorrhea acquired?

A: Sexual contact or perinatal transmission.

Q: What does Gonorrhea cause?

A: Urethritis, PID, infertility, neonatal eye infection.

Q: What are the major virulence factors of Gonorrhea?

A: Pili, IgA protease, Opa proteins, endotoxin, intracellullar leukocyte survival.

Q: Who is at risk for Gonorrhea?

A: Sexually active individuals.

Q: What are the key prevention and treatment principles for Gonorrhea?

A: Antibiotics and safe-sex.

Q: What is Syphilis?

A: A sexually transmitted infection caused by the spirochete Treponema pallidum.

Q: How is Syphilis acquired?

A: Sexual contact, cross-placenta, or direct contact with infectious lesions.

Q: What does Syphilis cause?

A: Incubation Stage —> Primary stage: Chancre → Secondary stage: rashes → latent stage: no symptoms → tertiary stage: gummas, neurological disease.

Q: What are the major virulence factors of Syphilis?

A: Outer membrane proteins, LPS, antigen variation.

Q: Who is at risk for Syphilis?

A: Sexually active individuals and fetuses.

Q: What are the key prevention and treatment principles for Syphilis?

A: Penicillin.

Q: What is Nongonococcal urethritis?

A: Urethritis not caused by N. gonorrhoeae; often due to Chlamydia.

Q: How is Nongonococcal urethritis acquired?

A: Sexual contact.

Q: What does Nongonococcal urethritis cause?

A: asymptomatic but can progress to PID in women.

Q: What are the major virulence factors of Nongonococcal urethritis pathogens?

A: Chlamydia intracellular growth; Mycoplasma adhesion.

Q: Who is at risk for Nongonococcal urethritis?

A: Sexually active individuals.

Q: What are the key prevention and treatment principles for Nongonococcal urethritis?

A: Antibiotics.

Q: What is Streptococcal pharyngitis “strep throat”?

A: Throat infection caused by Streptococcus pyogenes.

Q: How is Streptococcal pharyngitis acquired?

A: Respiratory droplets.

Q: What does Streptococcal pharyngitis cause?

A: Sore throat, fever, swollen tonsils and pharynx. Progress to rheumatic fever or glomerulonephritis.

Q: What are the major virulence factors of Streptococcal pharyngitis?

A: M protein, streptolysins, exotoxins.

Q: Who is at risk for Streptococcal pharyngitis?

A: Anyone.

Q: What are the key prevention and treatment principles for Streptococcal pharyngitis?

A: Penicillin and hygiene.

Q: What is Diphtheria?

A: Respiratory Infection caused by Corynebacterium diphtheriae.

Q: How is Diphtheria acquired?

A: Respiratory droplets.

Q: What does Diphtheria cause?

A: Pseudomembrane formation, airway obstruction, organ damage.

Q: What are the major virulence factors of Diphtheria?

A: Diphtheria toxin (inhibits protein synthesis).