Vertical transmission
1. Placental-fetal transmission- rubella infection during first trimester --> heart malformation, cataracts, deafness 2. Transmission during birth- gonococcal, chlamydial conjunctivitis 3. Postnatal transmission in maternal milk- CMV- HIV- HBV
Pathogens resistant to intracellular killing in phagocytes
- mycobacteria - Listeria - Cryptococcus neoformans - leishmania - trypanosomes - toxoplasmas
Genes for toxins found in plasmids
- cholera - diphtheria - botulism
Exotoxins
- Enzymes eg: exfoliative toxins produced by S. aureus cause staphylococcal scalded skin syndrome, SSSS, by degrading proteins that hold keratinocytes together) - Toxins that alter intracellular signaling or regulatory pathways (active subunit with enzymatic activity and binding subunit --> A-B toxins)eg: Bacillus antrhracis, V. cholerae, E. coli - Neurotoxinseg: Clostridium botulinum (blocks Ach-release --> paralysis)Clostridium tetani (blocks GABA/Glycin release --> spasm) - Superantigens stimulate T lymphocytes and lead to massive proliferation and cytokine releaseeg toxic shock syndrome (capillary leak, shock)
STIs
Viruses- Herpes simplex virus --> neonatal herpes- Hepatitis B virus --> hepatitis- Human papillomavirus --> condyloma acuminatum- HIV --> AIDS Chlamydia trachomatis --> lymphogranuloma venereum Bacteria- Neisseria gonorrhoeae --> urethritis, proctitis, pharyngitis- Treponema pallidum --> syphilis Protozoa- Trichomonas vaginalis
