Salmonella

Streptococcus pneumoniae

Haemophilus influenzae

Neisseria meningitidis

Klebsiella pneumoniae

Group B Strep

"S SHiN" + GBS + Klebsiella"

Passive Immunity given to pts after exposure to?

(List 4)

-preformed abs

• Tetanus toxin
• Botulinum toxin
• HBV
• Rabies virus

"To Be Healed Rapidly"

*Note: premature babies are also given passive immunization for RSV in winter mo

PAS

*Tropheryma whippelii

Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, & Yersina (pestis and pseudotuberculosis)

"Some Nasty Bugs May Live FacultativeLY"

ADP ribosylating A-B toxin:

inactivates EF-2

ADP ribosylating A-B toxin:

inactivates EF-2

ADP ribosylation of G_s (permanent activation) → adenylate cyclase activation → ↑ cAMP → ↑ Cl secretion and ↓ Na absorption, water follows → voluminous rice-water diarrhea

-encoded in a lysogenic phage

ADP ribosylating toxins:

heat-labile toxin stimulates adenylate cyclase → ↑ cAMP

heat-stabile toxin stimulates guanylate cyclase

*both cause watery diarrhea

"Labile like the Air, Stabile like the Ground"

ADP ribosylating toxin permanently disables Gα_i → ↑ AC activation → ↑ cAMP

*whooping cough, inhibits chemokine receptor causing lymphocytosis

"turns the off off"

α toxin is a lecithinase that acts as a phospholipase to cleave cell membrane → gas gangrene

*double zone of hemolysis on blood agar

blocks release of ACh

-encoded in a lysogenic phage (certain strains)

*CNS paralysis, esp. Cranial nerves

*spores in canned foods

*baby who eats honey → floppy baby

Shiga toxin

(& Shiga-like toxin - aka Vero cytotoxin)

cleaves host cell rRNA → inactivates 60S ribosome (inh. of protein syn.)

 -encoded in a lysogenic phage

*also produced by EHEC

*also enhances cytokine release and toxic to renal endothelial cells → HUS

*production enhanced by Fe def.

*Is an A-B toxin

activates guanylate cyclase

*watery diarrhea and electrolyte loss

Toxin A (enterotoxin) - causes diarrhea; binds to brush border

Toxin B (cytotoxin) - cytotoxic; destroys cytoskeleton (depolymerization of actin → cell death; MOA by binding and inhibiting cytosolic GTPases??)

*Dx C. diff by detecting one or both toxins in stool

• generalized - "packaging event", lytic phage
• specialized - "excision event", lysogenic phage

super antigen

causes Scarlet Fever

-encoded in a lysogenic phage

Novobiocin sensitive

*Staph saprophyticus is novobiocin resistant

"Fticus puts up a Fight"

• G+ rod
• beta hemolytic
• tumbling motility (@ 22°C)
• "actin rockets"
• only G+ w/ endotoxin
• meningitis in newborns
• unpasteurized milk/cheese and deli meats; vaginal transmission @ birth
• facultative intracellular microbe (CMI required for elim.)
• #3 cause of neonatal meningitis
• can cause spontaneous abortion

only bacterium w/ a polypeptide capsule?

(what does it contain?)

Bacillus anthracis

*D-glutamate

Actinomyces vs. Nocardia:

How to differentiate b/t long branching filaments resembling fungi

Actinomyces israelii: G+ anaerobe, normal oral flora, oral/facial abscesses (often after trauma), yellow "sulfur granules", tx w/ Penicillin

Nocardia asteroides: G+ but also weakly acid-fast, aerobe, soil resident, pulm. inf. in immunocompromised, Tx w/ sulfa

M. avium-intracellulare prophylactic Tx in AIDS pts?

(don't want disseminated dz)

2 Disease types (leprosy) caused by Mycobacterium leprae:

-and Tx

Lepromatous: more serious (diffuse, can be lethal), pts have weak T-cell mediated immunity, Th2 (humoral), Leonine facies

Tuberculoid: just a few nodules, intact T-cell response, Th1 response (CMI!)

*M. leprae infects skin and superficial nn., armadillo reservoir

Tx: long-term oral dapsone (hemolysis, methemoglobinemia), *watch for G6PD def.

2 G- comma shaped bacteria:

what are they and how do you differentiate?

Campylobacter jejuni - grows in 42°C

Vibrio cholera - grows in alkaline media

*both are ox+

Rifampin

*Rifampin prophylaxis is also used for close contacts of pts w/ H.inf type B meningitis

Legionella pneumophila (facultative intracellular organism):

• Stain?
• Culture media?
• Detection?
• Transmission?
• Tx?

• silver stain
• charcoal yeast extract w/ iron and cysteine
• presence of antigen in urine
• aerosol transmission from water source (NO person-to-person)
• Erythromycin (macrolides)

"VDRL"

• V for viruses (mono, hepatitis)
• D for drugs
• R for Rheumatic dz (fever, arthritis too?)
• L for Lupus and Leprosy

A, B, & C: cause trachoma - blindness due to follicular conjunctivitis in Africa; chronic infection "ABC for Africa/Blindness/Chronic"

D-K: urethritis/PID, neonatal pneumonia (staccato cough), neonatal conjunctivitis

L1-3: lymphogranuloma venereum - swollen, painful inguinal nodes that coalesce, ulcerate, and rupture; leads to fibrosis and anogenital strictures (vs. donovanosis by Klebsiella granulomatis w/ painless, beefy red inguinal ulcers)

*Tx all w/ azithromycin

Which systemic mycoses is the exception to being a yeast in tissue?

(not referring to cutaneous and opportunistic mycoses)

Coccidoides imitis

*spherule in tissue - filled w/ endospores, much larger than RBCs

• chorioretinitis
• hydrocephalus
• intracranial calcifications

*Tx for Toxoplasmosis is Sulfadiazine + pyrimethamine

Parvovirus B19

*ss, linear(-), and non-enveloped

*aplastic crises, "slapped cheeks" (5th dz), crosses placenta

Smallpox, yellow fever, chicken pox (VZV), Sabin's polio (oral), MMR, and intranasal influenza

"Live one night only! See small yellow chickens get vaccinated w/ Sabin's and MMR"

*influenza and yellow fever vaccines are egg based - allergic to egg?

*live attenuated - humoral and cell mediated immunity

*MMR is only live atten. that can be given to HIV+ pts

Rabies, Influenza (IM), Salk Polio, HAV

*humoral immunity only, need boosters

"RIP Always"

HBV - antigen is HBsAg

HPV - types 6, 11, 16, & 18

Circular DNA genome

1. papilloma
2. polyoma
3. hepadnaviruses

Reoviridae (R. coltivirus - colorado tick fever)

Rotavirus (#1 cause of fatal diarrhea in children)

*both are non-enveloped; linear genome

"I went to a RETRO TOGA party, where I drank FLAVored CORONA and ate HIPPY CALIfornia PICKLES"

retrovirus, togavirus, flavivirus, coronavirus, hepevirus, calcivirus, picornavirus

*equate the party to a positive (stranded) experience

Retroviruses

-2 identical ssRNA molecules

*all other viruses are haploid (1 copy of DNA or RNA)

Poxvirus

*also note poxvirus purified dsDNA is not infectious (same for HBV)

influenza virus

retroviruses

"Naked CPR and PAPP smear + Hepevirus (HepE)"

Calicivirus, Picornavirus, Reovirus, Parvovirus, Adenovirus, Papilloma, Polyoma, and hepevirus

*Note Poxviruses and Paramyxoviruses are only 2 that start w/ P and are enveloped

Enveloped viruses that acquire envelope from nuclear membrane

(vs. all other from plasma membrane)

Herpesviruses

1, 2, VZV, EBV, CMV, HHV-6 & 8

reheated meat dishes

*C. perfringens causes watery diarrhea and gas gangrene

poultry, meat, eggs

*assoc. w/ pet reptiles (turtles, snakes)

Pasteurella multocida

*"my bones hurt from chasing animals in the pasture"

TORCHeS

& their classic neonatal manifestations

• T - Toxoplasma gondii - chorioretinitis, hydrocephalus, intracranial calcifications
• O - Other (=Parvovirus B19) - hydrops fetalis
• R - Rubella - PDA or pulmonary artery hypoplasia, cataracts, deafness, +/- "blueberry muffin" rash (purpura)
• C - CMV - most common; hearing loss (unilateral), seizures, petechial rash
  
• H - HIV (recurrent inf. & chronic diarrhea; use zidovudine) & HSV -temporal encephalitis, herpetic (vesicular) lesions
• S - Syphilis - usu stillbirth, hydrops fetalis; if child survives: notched teeth, saddle nose, short maxilla, saber shins

Tropheryma whippelii (a Gram+ actinomycete)

MC Sx: arthralgias, diarrhea, abdominal pain, and weight loss; CNS involvement can occur

***small intestinal biopsy with periodic acid-Schiff (PAS)–positive, and diatase-resistant granules in macrophages with characteristic bacillus

Vancomycin, Fluoroquinolones, Penicillin, Aminoglycosides, Cephalosporins, Metronidazole

"Very Finely Proficient At Cell Murder"

Tetracyclines used for?

(tetracycline, doxycycline, demeclocycline, minocycline)

"VACUUM THe BedRoom"

Vibrio cholerae, Acne, Chlamydia, Ureaplasma Urealyticum, Mycoplasma pneumoniae, Tularemia, H. pylori, Borrelia burgdorferi, Rickettsia

*use doxy in pts w/ renal failure (is fecally eliminated)

Trimethoprim toxicities?

How do you alleviate them?

-megaloblastic anemia, leukopenia, granulocytopenia

-leucovorin rescue - supplemental folinic acid (bypasses DHFR step)

Polymyxins

Examples?

MOA?

Use?

Toxicity?

-Polymyxin B, Colistin

-Binds cell membranes and disrupts osmotic integrity (are cationic basic proteins acting like detergents)

-resistant G- inf. ("last resort against multidrug resistant Pseudomonas"

-neurotoxicity, acute renal tubular necrosis (ATN)

Prophylaxis: isoniazid

Treatment:

• Rifampin - inhibits DNA-dep RNA polymerase, orange body fluids; also prophylactic for HinfB and meningococcus
• Isoniazid - inhibits syn. of mycolic acids (bacterial catalase-peroxidase has to activate it); lupus, neurotoxic due to pyridoxine def, hepatotoxic
• Pyrazinamide - requires acidic environ. (engulfed TB in phagolysomes); hepatoxic, arthralgias
• Ethambutol - inhibits arabinosyltransferase (carb. polymerization of cell wall); optic neuropathy (red-green color blindness, central scotoma; reversible)

Prophylaxis: azithromycin (start when CD4 <100)

Tx: azithromycin, rifampin, ethambutol, streptomycin

Dapsone (same MOA as sulfonamides - PABA antimetabolite inhibiting dihyropteroate synthetase)

rifampin

clofazimine (binds guanine bases of DNA preventing DNA use as a template, increases PLA₂ activity)

Nystatin

"swish and swallow"

Initial Tx upon Dx is Amphotericin B, usu w/ addition of Flucytosine

(ampho B does NOT cross BBB and must be given intrathecally)

Maintenance Therapy for Life: Fluconazole

-the azole that can cross the BBB

Nevirapine, Efavirenz, Delaviridine

*non-competitive, do NOT require phosphorylation

S. aureus: TSST-1 (TSS), enterotoxins (food poisoning), exfoliatin (SSSS)

S. pyogenes: erythrogenic toxen (toxic shock-like syndrome)

very HIGH fever in a smoker accompanied by diarrhea, confusion, and cough causing chest pain; radiographic evidence of pneumonia

Tx w/ erythromycin

*Legionella is a G- rod, but often no bacteria seen in sputum gram stain; test for anitgen in urine

*more in eldery vs. Mycoplasma in young

*NOT always going to see the assoc. w/ water in the ?