Systems Flashcards
1
Q
Normal flora of tissues
A
Skin - S. epidermidis
Nose - S. epidermidis; colonized by S. aureus
Oropharynx - Viridans group strep
Dental plaque - S. mutans
Colon - B. fragilis > E. coli
Vagina - Lactobacillus; colonized by E. coli/GBS
C-section babies have no flora, colonized after birth
2
Q
Bugs causing food poisoning:
- Reheat rice
- Canned food/honey
- Reheated meat
- Undercooked meat
- Poultry/eggs
- Meats/mayo/custard
- Shellfish/wounds from water or shellfish
A
- B. cereus - reheated rice
- C. botulinum - improperly canned foods (bulging can) = preformed toxin; honey spores
- C. perfringens - reheated meat dishes
- EHEC (O157:H7) - undercooked meat
- Salmonella - poultry, meat, eggs
- S. aureus - Meats, mayo, custard; performed toxin
- V. parahaemolyticus/V. vulnificus - contaminated seafood (shellfish) or wounds from water/shellfish
3
Q
Bugs causing diarrhea: bloody vs. watery
A
Bloody diarrhea (ChEEESSY)
- Campylobacter
- E. histolytica
- EHEC (enterohemorrhagic)
- EIEC (enteroinvasive)
- Salmonella
- Shigella
- Y. enterocolitica
Watery diarrhea (CCEPVV)
- C. difficile
- C. perfringens
- ETEC (enterotoxigenic)
- Protozoa
- V. cholerae
- Viruses
4
Q
Causes of bloody diarrhea
A
“ChEEESSY”
- Campylobacter - oxidase +, comma-shaped, grows at 42C
- E. histolytica - protozoan, amebic dysentery, liver abscess
- EHEC (enterohemorrhagic) - O157:H7 mutation, makes Shiga-like toxin (inhibit 60S subunit on ribosome = cell death); can cause HUS
- EIEC (enteroinvasive) - invades colonic mucosa
- Salmonella - lactose neg, oxidase neg, flagellar motility (animal reservoir; poultry/eggs)
- Shigella - lactose neg, oxidase neg, very low ID50 –> makes shiga-toxin
- Y. enterocolitica - day-care breakout, pseudoappendicitis
5
Q
Causes of water diarrhea
A
“CCEPVV”
- Clostridium difficile - pseudomembranous colitis, caused by abx. Sometimes bloody diarrhea
- Clostridium perfringens - myonecrosis and gas gangrene
- ETEC (enterotoxogenic) - Traveler’s diarrhea; heat-labile (HL) and heat-stable (ST) toxins
- Protozoa - Giardia, cryptosporidium (in immunocompromised)
- V. cholerae - comma-shaped gram neg, grows in alkaline environment (sensitive to pH); rice-water diarrhea, often from infected seafood
- Viruses - rotavirus, norovirus
6
Q
Causes of pneumoniae by age
A
- Neonates (<4wks): GBS, E. coli (think vagina)
- Kids (4wk-18yo): Viruses (RSV), Mycoplasma, C. trachomatis (0-3yo), C. pneumoniae (school-aged), S. pneumoniae
- Runts May Cough Chunky Sputum
- Adults (18-40yo): mycoplasma, C. pneumoniae, S. pneumoniae
- Adults (40-65yo): S. pneumoniae, H. influenzae, Anaerobes, Viruses, Mycoplasma
- Elderly: S. pnuemoniae, Influenza virus, Anaerobes, H. influenzae, Gram-neg
7
Q
Special groups of pneumoniae
- Alcoholic/IV drug user
- Aspiration
- Atypical
- CF
- Immunocompromised
- Nosocomial
- Postviral
A
- Alcoholic/IV drug user - S. pneumoniae, Klebsiella, Staph
- Aspiration - anerobes
- Atypical - mycoplasma, legionella, chlamydia
- CF - pseudomonas, S. aureus, S. pneumoniae
- Immunocompromised - Staph, enteric gram-neg rods, fungi, viruses, PCP (HIV)
- Nosocomial - Staph, pseudomonas, enteric gram-neg rods
- Postviral - staph, H. influenzae, S. pneumoniae
8
Q
Common causes of meningitis by age
A
- Newborn (0-6mo): GBS, E. Coli (think vagina), Listeria
- Kids (6mo-6yr): S. pnuemoniae, N. meningiditis, HiB, Enterovirus
- 6-60yo: S. pneumoniae, N. meningitidis (#1teens), enterovirus, HSV
- > 60yo: S. pneumoniae, Gram-neg rods, Listeria
- HiB meningitis much lower since vaccine introduction!
- Viral - enterococcus (Coxsackie), HSV2, HIV, West Nile, VZV
- In HIV - cryptococcus, CMV, toxo (brain absces), JC virus (PML)
9
Q
Tx for meningitis
A
Ceftriaxone + vanc empirically
- Add ampicillin if suspect listeria (very old/young)
10
Q
CSF findings in meningitis
A
Bacterial: incr openingP, high PMNs, incr protein, decr sugar
Fungal/TB: incr openingP, high lymphocytes, incr protein, decr sugar
Viral: normal/incr opening P, high lymphocytes, normal/incr protein, normal sugar
11
Q
Osteomyelitis
A
*Most in kids, high CPR/ESR; subtle on XR, cavity on MRI
- S. aureus - most common
- Neisseria gonorrhea - rare, more often causes septic arthritis
- Pseudomonas, serratia –> DM/IV drug users
- Salmonella - sickle cell
- S. aureus/S. epidermidis - prosthetic jt replacement
- M. TB (Pott) - vertebral involvement
- Pasteurella - cat/dog bites
12
Q
UTI = cystitis
A
Ascession of microbes from urethra to bladder
- Dysuria, frequency, urgency, suprapubic pain, WBCs (NOT WBC casts) in urine
- Males - infants with cong defects, vesicourethral reflex
- Elderly -enlarged prostate
- Females - 10x more common (short urethra w/ fecal flora)
Other risks: obstruction, kidney surgery, catheterization (pseudomonas), GU malformation, DM, pregnancy
13
Q
Pyelonephritis
A
Accession of microbes from bladder to kidney
- Fever, chills, flank pain, CV tenderness, hematuria, WBC casts
14
Q
UTI bugs
A
- E. coli - most common, green metallic sheen on EMB agar
- S. saphrophyticus - 2nd cause in sexually active women
- Klebsiella - 3rd cause, large mucoid capsule + viscous colonies
- Serratia m. - red pigment; nosocomial/drug-resistant
- Enterobacter - nosocomial/drug-resistant
- Proteus - motility –> “swarming” on agar, urease, struvite stones
- Pseudomonas aeruginosa - blue-green pig/fruity odor; nosocomial/drug-resistant
15
Q
Labs with UTI
A
- WBC = UTI
- WBC casts = pyelonephritis
- LE+ = bacterial UTI
- Nitrate+ = gram-neg UTI
- Urease = urease-producing bugs (Proteus, Klebsiella, H. pylori)
16
Q
Vaginal infections
A
Bacterial vaginosis - no inflammation, thin/white discharge with fishy odor
- Gardernella, clue cells, pH >4.5
- Tx = metronidazole
Trichomonas vaginalis - inflammation, frothy, grey-green, foul-smelling discharge
- Motile trichomonads, pH >4.5
- Tx = metronidazole; treat sexual ptnr
Candida vulvovaginitis - inflammation, thick, white, “cottage cheese” discharge
- Pseudohyphae, pH nl (4-4.5)
- Tx = -azoles
17
Q
ToRCHeS infections
A
ToRCHeS
- Toxo
- Rubella
- CMV
- HIV
- HSV-2
- Syphilis
18
Q
Congenital toxo
A
Get from cat feces/undercooked meat
- Maternal - asx, LAD rarely
- Neonatal - triad = chorioretinitis, hydrocephalus, intracranial calcifications
19
Q
Congenital rubella
A
Respiratory droplets
- Maternal - rash, LAD, arthritis
- Neonatal - triad = PDA, cataracts, deafness +/- blueberry muffin rash
20
Q
Congenital CMV
A
Sex, organ transplant
- Maternal - asx or mono-like illness
- Neonatal - hearing loss, sz, petechial rash, blueberry muffin rash
21
Q
Congenital HIV
A
Sex, needle stick
- Maternal - depends on CD4
- Neonatal - recurrent infections, chronic diarrhea
22
Q
Congenital HSV-2
A
Skin, mucous membrane contact
- Maternal - asx or herpetic (vesicular) lesions
- Neonatal - encephalitis, herpetic (vesicular lesions)
23
Q
Congenital syphillis
A
Sex
- Maternal - primary = chancre; secondary = dissem rash
- Neonatal - stillbirth, hydrops fetalis; if survives, have facial abnormalities (notched = Hutchingsons teeth, saddle nose, short maxilla, saber shins, CN VIII deafness
24
Q
Red rashes of childhood
A
“CHuMP = Red Small Vesicles”
- Coxsackievirus type A
- HHV-6
- Measles virus
- Parvovirus B19
- Rubella virus
- Strep pyogenes
- VZV
25
Coxsackievirus type A rash
Hand-foot-mouth disease
- Vesicular rash on palms/soles
- Vesicles/ulcers on oral mucosa
26
HHV-6 rash
Roseola
- Macular rash over body several days after high fever
- Can get febrilze szs; always in infants
27
Measles virus
Measles (rubeola)
- Paramyxovirus
- Rash preceded by CCCK (cough, coryza, conjunctivitis, Koplik spots (blue-white) on buccal mucosa
- Starts at head, moves down
28
Parvovirus B19
Fifth disease = erythema infectiosum
- P antigen in bone marrow (erythrocyte precursors); get from IgG/IgM-complex deposits
- "Slapped cheek" rash on face
- Hydrops fetalis in pregn women
29
Rubella virus
Rubella
- Rash starts on head --> moves down = fine truncal rash
- Postauricular LAD
30
Strep pyogenes
Scarlet fever
- Erythematous, sand-paper like rash with fever/sore throat
*GAS
31
VZV
Chickenpox
| - Vesicular rash starting on trunk --> spreads to face/extremities with diff aged lesions
32
STDs
- AIDS - OIs, kaposi sarcoma, lymphoma
* HIV
- Chancroid - painful genital ulcer, inguinal adenopathy
* Haemophilus ducreyi ("so painful you "do cry"!")
- Chlamydia - urethritis, cervicitis, conjunctivitis, reactive arthritis, PID
* Chlmaydria trachomatis (D-K)
- Condylomata acuminata - genital warts, koilocytes
* HPV 6 and 11
- Genital herpes - painful penil/vulvar/cervical vesicles + ulcers; systemic = fever, HA, myalgia
* HSV2 (HSV1 less common)
- Gonorrhea - urethritis, cervicitis, PID, prostatitis, epididymitis, arthritis, creamy purulent discharge
* Neisseria gonorrhoeae
- HBV - jaundice
- Lymphogranuloma venereum - lymphatic infection; painless genital ulcers, painful LAD (buboes)
* C. trachomatis
- Syphilis (primary-tertiary) - painless chancre, fever/LAD/rash/condylomata, gummas/tabes dorsalis, paresis, aortitis, Argyll Robertson pupil (diff stages)
* Treponema pallidum
- Trichomoniasis - vaginitis, strawberry cervix, motile in wet prep
* Trichomonas vaginalis
33
Pelvic inflammatory disease
PID
- Chlamydia trachomatis (subacute) = most common, Neisseria gonorrhoeae (acute)
- CMT (chandelier sign), purulent discharge
- Salpingitis, endometritis, hydrosalpinx, tubo-ovarian abscess
* Salpingitis = risk for ectopic, infertility, chronic pelvic pain, adhesions
* (Fitz-Hugh-Curtis syndrome - infection of liver capsule, 'violin string' adhesion of peritoneum to liver)
34
Nosocomial infections
- Candida albicans - hyperalimentation
- CMV/RSV - newborn nursery
- E. coli, proteus - urinary cath
- HBV - renal dialysis worker
- Legionella - water aerosols
- Pseudomonas - resp therapy equipment (and burns)
35
Bugs infecting immunized kids
- Rash - rubella/measles
- Meningitis - HiB, polio
- Epiglottitis - HiB (fever, dysphagia, drooling, cherry red epiglottis, thumbprint sign on XR)
- Pharyngitis - Corynebacterium diptheriae (gray oropharyng exudate = pseudomembrane, can obstruct throat)
36
Hint: asplenic pt
Encapsulated microbes = SHiN
| - S. pneumoniae>>HiB > N. meningiditis
37
Hint: branching rods in oral infection, sulfur granules
Actinomyces israelii
38
Hint: Chronic granulomatous disease
Catalase + bacteria (esp S. aureus; S. epidermiditis, S. saphyophyticus)
39
Hint: "Currant jelly" sputum
Klebsiella
40
Hint: Dog/cat bite
Pasteurella
41
Hint: Facial nerve palsy
Borrelia burgdorferi (Lyme)
42
Hint: Fungal infection in diabetic/immunocompromised
Mucor/Rhizopus spp.
43
Hint: Health care provier
HBV (needle stick)
44
Hint: Neutropenic pts
Candida albicans (systemic), aspergillus
45
Hint: Organ transplant recipient
CMV
46
Hint: PAS+
Tropherym whipplei (Whipple disease)
47
Hint: Pediatric infection
H. influenzae (epiglottitis)
48
Hint: Pneumonia in CF/burn
Pseudomonas
49
Hint: Pus, empyema, abscess
S. aureus
50
Hint: Rash hands/feet
Coxsackie A, Treponema pallidum, Rickettsia rickettsii
51
Hint: Sepsis/meningitis in newborn
GBS
52
Hint: Surgical wound
S. aureus
53
Hint: Traumatic open wound
Clostridium perfringens
