Microbio systemic

Question 1

Normal flora

Answer 1

Skin: staph epidermis
Nose: S epidermis, colonized by S aureus
Oropharynx: viridans groups Strep
Dental plaque: strep mutans
Colon: bacteroides fragilis > E coli
Vagina: lactobacillus, colonzied by E coli and group B strep

Question 2

Bugs causing food poisoning

Answer 2

Vibrio parahaemolyticus/ V. vulnificus ( from wound infection from contact with water/shellfish) = contaminated seafood

B cereus: heated rice
S. aureus: meat, mayo, custard, preformed toxin
C. perfringens: reheated MEAT dishes
C boltulinum: improperly canned food (budging can)
E coli O157:H7: undercooked meat
Salmonella: poultry, meat and eggs

S aures and B cereus start fast and end fast

Question 3

Bugs that mimic appendicitis

Answer 3

1) Yersinia entercolitica: most common cause of mesenteric adenitis, a disease that mimics appendicitis

2) nontyphoidal salmonella:
3) campy jejuni

Question 4

Prion

Answer 4

Conversion of normal cellular prion PrPc to a beta pleated form PrPsc, which is transmissible

PrPsc resists degradation and facilitates the conversion of still more PrPc to PrPsc.

Accumulation of PrPsc results in spongiform encephalopathy and dementia, ataxia and death.

Sporadic (Creutzfeld-Jacob=rapidly progressive dementia)
Inherited (Gertmann-Straussler-Scheinker syndrome)
Acquired (kuru)

Question 5

Special groups

Answer 5

Nosocomial: staphy, enteric gram negative rods
Immunocomp: staphy, enteric gram negative rods, fungi, vius, PCP (<200)
Aspiration: anaerobe (Klebsiella)
Alcoholic/IV drug users: S pneumo, Klebsiella, staphy
Cystic fibrosis: pseudomonas, S aureus, S pneumo
Postiviral: staph, H influenza, S pneumo
Atypical: mycoplasma, legionella, chlamydia

Question 6

STD specials to know

Answer 6

2’ syphilis: fever, LAD, skin rashes, condhylomata lata

3’ syphilis: gummas, tabes dorsalis, general paresis, aortitis, Argyll Robertson pupil

Chancroid: painful genital ulcers, inguinal adenopathy
Caused by Haemophilius ducreyi
“it’s so painful you DO CRY”

Chlamydia: urethritis, cervicitis, conjunctivitis, Reiter’s syndrome (conjunctivitis, urethritis, arthritis), PID.
Caused by C trachomatis D-K

Lymphogranuloma venereum: infection of lymphatics, genital ulcers, LAD, rectal strictures
Caused by C trachiomatis L1-3

Trichomoniasis: vaginitis, strawberry colored mucosa, motile on wet prep

Question 7

PID

Answer 7

Top bugs: C trachomatis (subacute, often undxed), N gonorrhea (acute),

C trachomatis: the most common bacterial STD in the US.

Cervical motion tenderness (Chandelier sign)

PID may include salpingitis, endometritis, hydrosalpinx and tubo-ovarian abscesses

Can lead to Fitz-Huge-Curtis: infection of the liver capsule and violin string adhesions of parietal peritoneum to liver.

Salpingitis is a risk factor for ectopic pregnancy, infertility, chronic pelvic pain, and adhesions.