202
General Microbiology II

Infection and Immunity Lecture Outlines

Host Parasite Relationships

Principles of Infectious Disease

Definitions

• Host

• Parasite

• Disease
  • symptom

  • sign

• Infectious disease

• Pathogen

• Virulence
  • Virulent

  • Attenuated

  • Avirulent

  • Opportunistic

Koch's Postulates

If a microorganism is the causative (etiologic) agent of an infectious disease, it must be:

• Present

• Isolated

• Able to Cause

• Re-isolated

Steps in Pathogenesis

To cause disease, a pathogen must:

• Contact

• Colonize

• Infect

• Evade

• Damage

Virulence Factors

Factors affecting invasiveness and/or toxigenicity

• Adhesins

• Invasins

• Evasins

• Toxins
  • exotoxins

  • endotoxin

Concepts of Immunology

Resistance

• External resistance factors
  • physical

  • chemical

  • cellular

• Internal resistance factors
  • physical

  • chemical

  • cellular
    • inflammation
    • phagocytosis

Immunity

• Antibody-mediated immunity (AMI)
  • antibody responses

  • mechanisms of action
    • neutralization

    • antibody/complement-mediated lysis

    • opsonization

• Cell-mediated immunity (CMI)
  • cellular responses

  • mechanisms of action
    • CTLs

    • activated macrophages

Vaccines

• toxoid

• killed

• live attenuated

• recombinant

Chemotherapeutic agents (CTAs)

• origin

• mechanisms of action

• spectrum

• selective toxicity

• resistance

• effectiveness

• testing bacterial and fungal cultures for antibiotic sensitivity

Epidemiology and Public Health Microbiology

Definitions

• Epidemiology

• Epidemic

• Prevalence

• Incidence

• Pandemic

• Endemic

• Outbreak

• Morbidity

• Mortality

• Reservoir

• Carrier

• Zoonoses

• Vector

• Fomite

Transmission of Infectious Diseases

• Stages in transmission

• Modes of transmission

Types of Epidemics

• Common-source

• Propagated

Nosocomial (hospital-acquired) Infections

• Iatrogenic infection

• Transmission

• Immunocompromised

• Antibiotic-resistant strains

Public Health Measures for Control of Epidemics

• Immunization of people

• Blocking vehicle-mediated transmission

• Quarantine

• Elimination of animal reservoirs

Diseases Transmitted by Skin Infection

Background

• Anatomy and associated host defense factors
  • epidermis
    • physical

    • chemical

    • cellular

  • dermis
    • physical

    • chemical

       

    • cellular

• Epidemiology
  • transmission

  • predisposing factors

Skin Diseases

• Acne
  • epidemiology: Propionibacterium acnes (bacterium)

  • pathogenesis:

  • treatment:

  • prevention:

• Furuncle (boil)
  • epidemiology: Staphylococcus aureus (bacterium)

  • pathogenesis:

  • treatment:

  • prevention:

• Candidiasis
  • epidemiology: caused by Candida albicans (fungus)

  • pathogenesis:

  • treatment:

  • prevention:

• Tineas (ringworm)
  • epidemiology: Epidermophyton, Microsporium, or Trichophyton (fungi)

  • pathogenesis:

  • treatment:

  • prevention:

• Warts (verruca vulgaris)
  • epidemiology: Papilloma viruses

  • pathogenesis:

  • treatment:

  • prevention:

• Herpes
  • epidemiology: Herpes simplex I virus

  • pathogenesis:

  • treatment:

  • prevention:

• Tetanus
  • epidemiology: Clostridium tetani (bacterium)

  • pathogenesis:

  • treatment:

  • prevention:

         

• Anthrax
  • epidemiology: Bacillus anthracis, an endospore-forming soil bacterium

  • pathogenesis:

  • treatment: antibiotics

    prevention: vaccine; avoid contact

• Lyme Disease
  • epidemiology: Borrelia burgdorferi (bacterium)

  • pathogenesis:

  • treatment:

  • prevention

• West Nile Fever
  • epidemiology: West Nile virus

  • pathogenesis:

  • treatment:

  • prevention

Diseases Transmitted by Respiratory Infection

Background

• Anatomy and associated host defense factors
  • upper respiratory tract
    • physical

    • chemical

    • cellular

  • lower respiratory tract
    • physical

    • chemical

    • cellular

• Epidemiology of Respiratory Infections
  • transmission

  • predisposing factors

Respiratory Diseases

• Acute Common Coryza (Common Cold)
  • epidemiology: Rhinovirus, Adenovirus, Respiratory Syncytial Viruses, etc.

  • pathogenesis:

  • treatment:

  • prevention:

• Influenza
  • epidemiology: Influenza Virus

  • pathogenesis:

  • treatment:

  • prevention:

• Pneumonia
  • epidemiology: Streptococcus pneumoniae (bacterium)

  • pathogenesis:

  • treatment:

  • prevention:

• Infectious Mononucleosis
  • epidemiology: Epstein-Barr Virus (EBV) and Cytomegalovirus

  • pathogenesis:

  • treatment:

  • prevention:

• Diphtheria
  • epidemiology: Corynebacterium diphtheriae (bacterium)

  • pathogenesis:

  • treatment:

  • prevention:

• Pertussis (whooping cough)
  • epidemiology: Bordetella pertussis (bacterium)

  • pathogenesis:

  • treatment:

  • prevention:

• Tuberculosis
  • epidemiology: Mycobacterium tuberculosis (bacterium)

  • pathogenesis:

  • treatment:

  • prevention:

• Histoplasmosis
  • epidemiology: Histoplasma capsulatum (fungus)

  • pathogenesis:

  • treatment:

  • prevention:

Diseases Transmitted by Gastrointestinal Infection

Background

• Anatomy and associated host defense factors
  • oral cavity (mouth), pharynx (throat), esophagus
    • physical

    • chemical

    • cellular

  • stomach
    • physical

    • chemical

    • cellular

  • small intestine
    • physical

    • chemical

    • cellular

  • large intestine - includes colon, rectum and anus
    • physical

    • chemical

    • cellular

• Epidemiology of Gastrointestinal Infections
  • transmission

  • predisposing factors

  • incidence

Gastrointestinal Diseases

• Dental Caries
  • epidemiology: Streptococcus mutans - other acidogenic normal microbiota, including S. sanguis, S. mitis and S. salivarius (bacteria)

  • pathogenesis:

  • treatment:

  • prevention:

• Periodontal Disease - Acute Necrotizing Ulcerative Gingivitis (ANUG)
  • epidemiology: Bacteriodes forsythus, Leptotrichia buccalis, Pophyromonas gingivalis, Treponema vincentii and Eikenella spp. (normal bacterial microbiota)

  • pathogenesis:

  • treatment:

  • prevention:

• Thrush
  • epidemiology: Candida albicans (fungus)

  • pathogenesis:

  • treatment:

  • prevention:

• Helicobacter Peptic Disease Syndrome (Ulcers)
  • epidemiology: Helicobacter pylori (bacterium)

  • pathogenesis:

  • treatment:

  • prevention:

• Food Intoxication
  • epidemiology: Clostridium botulinum, Staphylococcus aureus (bacteria); Aspergillus flavus (fungus)

  • pathogenesis:

  • treatment:

  • prevention:

• Enteritis
  • epidemiology: Salmonella enteritidis, Escherichia coli, Bacillus cereus, Clostridium perfringens, Campylobacter jejuni (bacteria); Rotavirus , Coxsackie virus, Echovirus (viruses)

  • pathogenesis:

  • treatment:

  • prevention:

• Cholera
  • epidemiology: Vibrio cholerae (bacterium)

  • pathogenesis:

  • treatment:

  • prevention:

• Hepatitis A
  • epidemiology: Hepatitis Virus

  • pathogenesis:

  • treatment:

  • prevention:

• Poliomyelitis
  • epidemiology: Polio Virus

  • pathogenesis:

  • treatment:

  • prevention:

Diseases Transmitted by Genitourinary Infection

Background

• Anatomy and associated host defense factors
  • urinary tract (male and female) - urethra, bladder, ureters and kidneys
    • physical

    • chemical

    • cellular

  • genital tract (male) - urethra (see above), seminal ducts
    • physical

    • chemical

    • cellular

  • genital tract (female) - vagina, uterus, fallopian tubes
    • physical

    • chemical

    • cellular

  • external genitalia
    • physical

    • chemical

    • cellular

• Epidemiology of Genitourinary Infections
  • etiology
    • urinary tract infections

    • genital tract infections

  • predisposing factors
    • sexually transmitted diseases (STDs)

    • non-STDs

• STD Hotline - (800) 227-8922
• AIDS Hotlines

Genitourinary Diseases

• Urinary cystitis and urethritis
  • epidemiology: Escherichia coli, other bacteria, some fungi

  • pathogenesis:

  • treatment:

  • prevention:

• Vaginosis
  • epidemiology: Candida albicans (fungus); Gardnerella vaginalis (bacterium); Trichomonas vaginalis (protozoan)

  • pathogenesis:

  • treatment:

  • prevention:

• Gonorrhea
  • epidemiology: Neisseria gonorrhoeae (bacterium)

  • pathogenesis:

  • treatment:

  • prevention:

• Chlamydial Disease
  • epidemiology: Chlamydia trachomatis (bacterium)

  • pathogenesis:

  • treatment:

  • prevention:

• Syphilis
  • epidemiology: Treponema pallidum (bacterium)

  • pathogenesis:

  • treatment:

  • prevention:

• Genital Herpes
  • epidemiology: Herpes Simplex Virus II (HSV-II)

  • pathogenesis:

  • treatment:

  • prevention:

• Genital Warts
  • epidemiology: Human Papilloma Viruses

  • pathogenesis:

  • treatment:

  • prevention:

• Hepatitis B, C and D
  • epidemiology: Hepatitis Virus B

  • pathogenesis:

  • treatment:

  • prevention:

• Acquired Immunodeficiency Syndrome (AIDS)
  • epidemiology: Human Immunodeficiency Virus (HIV)

  • pathogenesis:

  • treatment:

  • prevention:

A Guide to Safer Sex

• Be selective.
• Limit your sex partners.
• Use condoms.
• Do what's safest.
• Make sex good by doing only what feels right.
• Get tested.
• Watch for genital sores or unusual discharges.