MEDICAL MICROBIOLOGY REVIEW
ANATOMICAL SITE APPROACH

  1. BRAIN
    1. Abscess - Bacteroides
    2. Lesions - Toxoplasma gondii, cysticercosis
    3. Dementia - Treponema pallidum
    4. Encephalitis - viral or bacterial; parasitic (Toxoplasmic encephalitis)
    5. Meningitis - viral or bacterial (Neisseria meningitidis)

  1. SINUSES
    1. Streptococcus pneumoniae
    2. Haemophilus influenza

  1. EARS
    1. otitis media - Haemophilus influenza
    2. otitis interna
    3. Mycobacterium leprae

  1. EYES
    1. Conjunctivitis
      1. Chlamydia trachomatis
      2. Haemophilus aegyptius (H. influenza biogroup aegyptius)
      3. Neisseria gonorrhoeae

  1. NOSE
    1. Staphylococcus aureus
    2. Corynebacterium sp.
    3. Moraxella/Branhamella

  1. MOUTH
    1. Staphylococcus aureus
    2. Streptococcus sp. (especially viridans Streptococci in tooth decay)
    3. Prevotella melaninoginicus - tooth abscess
    4. Actinomyces israelii - lumpy jaw

  1. THROAT
    1. Corynebacterium diphtheria
    2. Streptococcus pyogenes & Group A Strep.
    3. Viral pharyngitis - Epstein Barr Virus
    4. Neisseria gonorrhoeae

  1. UPPER CHEST
    1. Upper Respiratory Infection
      1. Viral etiology
      2. Bacterial etiology
    2. Shoulders
      1. Rheumatoid arthritis
      2. Pyomyositis - Staphylococcus aureus or Streptococcus pyogenes

  1. LOWER CHEST
    1. Heart - Chagas disease (Trypanosoma cruzi, congestive heart failure (assoicated with bacterial respiratory infection), endocarditis (Staphylococcus aureus, coagulase-negative Staphylococci, Streptococcus, Enterococcus
    2. Lower lungs
      1. Pneumonia
        2. Atypical pneumonia Walking pneumonia
      2. Alveolar macrophages and intact mucocilliary escalator are especially important in prevention of infection
        With Legionnaire's disease and TB, macrophages become engorged with bacteria and overwhelm the normal killing mechanisms. Organisms like Bordetella pertussis that poison the ciliated epithelial cells, cause respiratory dysfunction as a disease symptom.

  1. UPPER GASTROINTESTINAL SYSTEM
    1. Stomach - Helicobacter pylori, Campylobacter jejuni
    2. Liver
      1. Hepatitis - Viral
      2. Parasite localization - Hepatic portal circulation (Schistosoma hematobium)
      3. Amoebic liver abscess - Entamoeba histolytica

  1. SMALL INTESTINES
    1. Diverticulitis - Bacteriodes fragilis, polymicrobial infection
    2. Vibrio cholerae, Escherichia coli (LT/ST strains), Rotavirus, Norwalk virus,
      Giardia lamblia, Cryptosporidium
    3. Pain localized to midabdomen
    4. Large stool volume, watery

  1. LOWER INTESTINES
    1. Shigella, E. coli (EIEC), Campylobacter, Entamoeba histolytica
    2. Pain localized to lower abdomen, rectum
    3. Small stool volume, mucoid, Blood and WBCs in stool

  1. GENITAL TRACT
    1. FEMALE TRACT - Neisseria gonorrhoeae, Chlamydia trachomatis, Gardnerella vaginalis, Treponema pallidum, HSV-2, HPV
      1. Increased UTI frequency in females due to close proximity of urethra to anus, shorter urethra in the female, and the dynamics of sexual intercourse promoting ascension of the bacteria up the urethra to the bladder
    2. MALE TRACT - Organisms same as for female
      1. Obstruction of urethra by enlarged prostate may predispose to UTI
      2. Antibacterial nature of seminal fluid may inhibit UTI

  1. UPPER URINARY TRACT
    1. Ascent to kidney facilitated by adhesins (P-pili in E. coli), neurological disease, pregnancy and reflux (incomplete emptying of the bladder)
    2. Pyelonephritis - infection of the kidney parenchyma

  1. LOWER URINARY TRACT
    1. Cystitis is the most common type of UTI
    2. 80% of uncomplicated UTI are caused by E. coli and Proteus mirabilis
    3. 20% of uncomplicated UTI are caused by Staphylococcus saprophyticus, Enterococcus faecalis, Group B Streptococci or Chlamydiae
    4. Complicated/Nosocomial UTI make up about 20% of ALL UTI and are most commonly caused by Enterobacteriaceae other than E. coli or Proteus mirabilis, Pseudomonas aeruginosa, Serratia marcescens, E. coli and Klebsiella pneumoniae

  1. LEGS AND FEET
    1. Tinea pedis caused by dermatophyte fungi
    2. Cellulitis - infection of the fascia most commonly caused by Staphyloccus sp. or Streptococcus sp.
    3. Puncture wounds (Clostridium tetani), penetration of parasite larvae

  1. ARMS AND HANDS
    1. Tinea corporis caused by dermatophyte fungi
    2. Candida albicans infection localized to cracked, dry hands
    3. Herpetic whitlow (HSV)
    4. Cellulitis (see above)
    5. Sporothrix schenkii fungal infection

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E-mail Dr. Johnson
johnsomt (at) iupui.edu
for comments or suggestions.		 Authored by Mary T. Johnson, Ph.D.
©Copyright 1999-2007, Indiana University School of Medicine
Last modified December 29, 2007