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Microbiology ` microbiology—systems Microbiology ` microbiology—systems SEcTioN ii 185

Pelvic inflammatory Top bugs—Chlamydia trachomatis (subacute, Salpingitis is a risk factor for ectopic pregnancy,
disease often undiagnosed), Neisseria gonorrhoeae infertility, chronic pelvic pain, and adhesions.
(acute). Can lead to perihepatitis (Fitz-Hugh–Curtis
A
C trachomatis—most common bacterial STI in syndrome)—infection and inflammation of
the United States. liver capsule and “violin string” adhesions of
Signs include cervical motion tenderness, peritoneum to liver B .
adnexal tenderness, purulent cervical
discharge A .
PID may include salpingitis, endometritis,
hydrosalpinx, and tubo-ovarian abscess.
B

Nosocomial infections E coli (UTI) and S aureus (wound infection) are the two most common causes.
risK Factor PatHogeN UNiQUe sigNs/symPtoms
Antibiotic use Clostridium difficile Watery diarrhea, leukocytosis
Aspiration (2° to Polymicrobial, gram ⊝ bacteria, often Right lower lobe infiltrate or right upper/
altered mental status, anaerobes middle lobe (patient recumbent); purulent
old age) malodorous sputum
Decubitus ulcers, S aureus (including MRSA), gram ⊝ anaerobes Erythema, tenderness, induration, drainage
surgical wounds, (Bacteroides, Prevotella, Fusobacterium) from surgical wound sites
drains

Intravascular catheters S aureus (including MRSA), S epidermidis (long Erythema, induration, tenderness, drainage
term), Enterobacter from access sites
Mechanical ventilation, Late onset: P aeruginosa, Klebsiella, New infiltrate on CXR,  sputum production;
endotracheal Acinetobacter, S aureus sweet odor (Pseudomonas)
intubation
Renal dialysis unit, HBV, HCV
needlestick
Urinary catheterization Proteus spp, E coli, Klebsiella (infections in your Dysuria, leukocytosis, flank pain or
PEcKer) costovertebral angle tenderness
Water aerosols Legionella Signs of pneumonia, GI symptoms (diarrhea,
nausea, vomiting), neurologic abnormalities

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