Gram + Rods

Question 1

Bacillus

Answer 1

Spore forming

Aerobic

Secrete exotoxin

Question 2

Clostridium

Answer 2

Spore forming

anaerobic

Seretes exotoxin

Question 3

Listeria

Answer 3

Aerobic growth

Factulative Intracellula

infects immunocompromised hosts

Question 4

Corynebacterium

Answer 4

Aerobic growth

Secretes exotoxin

Question 5

Actinomyces

Answer 5

anaerobic growth

branching rods

Question 6

Nocardia

Answer 6

Aerobic growth

Immunocompromised hosts

partially acid fast

branching rods

Question 7

Mycobacterium

Answer 7

Aerobic growth

faculative intracellular

Immunocompromised hosts

Acid Fast

Question 8

Bacillus anthracis

Answer 8

Box-car like

Polypeptide capsule

Biowarfare Agent (large crowds in vignette)

Cutaneous: Papule, necrotic–> black eschar

Pulmonary: “Wool Sorters” life threatening pneumonia, widening mediastinum on CXR

GI: rare, edema & blockage of GI tract

Anthrax toxin: made up of Lethal factor (kills cells), edema factor (AC–> inc cAMP)

Toxoid VACCINE- given to high risk occupations

Question 9

Bacillus cereus

Answer 9

Foodborne

Fried rice from chinese buffet where food is kept warm not hot

Gastroenteritis: nonblooding emesis

Emetic toxin: preformed 1-6 hrs

Question 10

Gram + rod

spore forming

Anaerobic

Answer 10

Clostridium

Question 11

Tetanus toxin- inhbitis release of GABA/Glycine (inhbitory NT)

Spastic paralysis (risus sardonicus, opisthotonus, extreme muscle spasms)

Transmission: puncture wounds/ human bites

reservoir: soil

VACCINE- toxoid

TX: Anti-toxin, Ig, spasmolytics

Answer 11

Clostridium tetani

Question 12

foodborne (honey, poorly canned foods)

soil

toxin coded by phage, heat labile, blocks Ach release

flaccid paralysis

Answer 12

Clostridium botulinum

Question 13

preformed toxin ingested

poorly canned alkaline vegetables, smoked fish

1-2 days onset

blurred vision, dizziness

tx: respiratory support, anti-toxin

**Abx not helpful b/c intoxication not infection

Answer 13

Adult Clostridium botulinum intoxication

Question 14

Spores ingested (honey)–> infection

toxin is produced in gut

Constipation, weak feeding, decreased crying

Abx not used

Answer 14

Infant Clostridium botulinum

Question 15

Stormy fermentation in milk media

double zone of hemolysis

soil

traumatic implantation

alpha toxin (lecithinase)–> disrupts cell membranes

Nagler rxn identifies alpha toxin (egg yolg agar)

Answer 15

Clostridium perfringens

Question 16

dirty wound from traumatic accident

tense tissue (edema, gas)

due to alpha toxin (lecithinase)

rapid, high mortality

tx: debridment, delayed closure, clindamycin

Answer 16

Gas gangrene (myonecrosis)

Question 17

normal flora

endogenous transmission

Use of broad spectrum abx: clindamycin, cephalosporins, amoxicillin, ampicillin

diarrhea, colitis, psuedomembranous colitis (yellow plaques on colon)

stool exam for culture

tx: metronidazole

Answer 17

Clostridium difficile

Question 18

Gram +

non spore forming

Faculative intracellular

tumbling motility

Answer 18

Listeria

Question 19

Beta hemolytic gram + rod

Actin jet motility

cold growth (soft cheeses, deli meat)

unpasteurized milk

foodborne, vertical, placental

Answer 19

Listeria monocytogenes

Question 20

Healthy pts: gastroenteritis after ingestion of soft cheeses, deli meats, hot dogs

Pregnant women: septicemia: fever, chills. Can cross placenta

Neonatal disease:

Early Onset: in utero- sepsis high mortality rate, disseminated granulomas (faculative intracellular) w/ central necrosis

Late Onset: 2-3 wks after birth from fecal exposure. Meningitis

Immunocompromised: meningitis in renal transplant pts & cancer pts.

tx: ampicillin w/ gentamycin

Answer 20

Listerosis

Question 21

Gram + rods, clubbed shaped

“chinese letters” on tellurite medium

aerobic

Toxin- encoded by phage; inhibits ribosylation of eE-2 (ihibiting protein synthesis)

throat/nasopharynx- respiratory droplets

Not invasive, colonizes epithelium

dirty gray psudomembrane

Elek test- test for toxin

Tx: erythromycin, anti-toxin

VACCINE

Answer 21

Corynebacterium diptheriae

Question 22

Brancing Rods

Invasive growth

Cervicofacial (lumpy jaw)

Tissue swelling–> abcess formation–> draining abcess w/ sulfur granules in exudate

Pelvic- IUDs

CNS- solitary brain abcess

Tx: PCN, drainage

Answer 22

Actinomyces israelii

Question 23

Aerobib branching rod

partially acid fast

airborne/traumatic implantation

inc. risk- immunocompromised

Cavitary bronchopulmonary: cough, fever, dypsnea, pneumonia w/ caviation

Cutaneous/subcutaneous: celluitis w/ swelling–> drianing abscess w/ granules

tx: sulfonamides (high doses), TMP-SMX

Answer 23

Nocardi

(N. asteroides, N. brasiliensis)

Question 24

Acid fast rods

obligate aerobes

High [lipids]–> mycolic acid

resistant to drying, chemicals

sensitive to UV light

cannot be cultures

tx: multiple rx tx; dapsone, rifampin

dapsone for close family members

Answer 24

Mycobacterium

Question 25

Slow growing (3-6 wks) Faculative intracellular\*\* Most important virulence factor Tuberculin- surface protein--\> Type IV hypersensitivity

Answer 25

Mycobacterium tuberculosis

Question 26

Likes apex of the lungs **Ghon focus** (replication w/in alveolar macrophages) Macrophges transport bacili to lymph nodes **Ghon Complex** Organisms are walled off--\> granuloma

Answer 26

Primary pulmonary TB

Question 27

Granulomas erode into airway due to decreased T cell immunity Mycobacterial replication Disease symptoms May disseminate (miliary TB)

Answer 27

Reactivation TB

Question 28

Dx of TB

Answer 28

Screen: Auramine-rhodamine stain (fluorescent apple green) Confrim: Acif fast stain PPD skin test **indicates exposure** not active disease No serodiagnosis

Question 29

BCG Vaccine **NOT IN USA** Multiple drug therapy 1st 2 months: isoniazid, rifampin, pyrazinamide next 4 months: isoniazin, rifampin Ethambutol or streptomycin added for rx resistant cases

Answer 29

Tx of TB

Question 30

MAC M. avium intaracellulare (non-chromogen) M. kanasii (photochromogen)

Answer 30

Pulmonary, GI & disseminated disease Respirtory transmission AIDSs pts (CD4\< 50), cancer chronic lung disease

Question 31

Soft tissu infxn fish tank granuloma transmitted via abraisions cutaneous granulomas tropical fish enthusiasts

Answer 31

Mycobacterium marinum

Question 32

Acid fast (punch biopsy) obligate aerobe obligate intracellular like temps below body temp Reservoir: mucosa, skin, nerves, armadillos Transmission: nasal discharge

Answer 32

Mycobacerterium leprae

Question 33

Strong CMI (TH1) Lepromin skin test + CMI--\>granuloma formation---\> nerve impingement/damage---\> loss of sensation Macular lesions, nerve enlargement

Answer 33

Tuberculoid M. leprae

Question 34

Weak CMI (TH2) Lepromin skin test - high # organisms (intracellular) nerve damage from over growth of bacteria---\> loss of sensation Numberous nodular lesions, loss of eyebrows, destruction of nasal septum Leonine facies

Answer 34

Lepromatous M. leprae