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For: enterobacteriaceae, salmonella, shigella, norovirus, rotavirus & HAV, HBV, entamoeba histolytica, giardia
see related sessions
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For Yersinia enterocolitica describe:
features
transmission
pathogenesis
associated diseases
- G-, pleomorphic rods
- carried by pigs, cattle, rodents, etc
- can grow at 4C, often contaminates milk (to culture might need "cold enrichment"
- associated diseases:
- acute enterocolitis
- mesetneric lymphadenitis (can mimic appendicitis)
- mucosal ulcerations
- septicemia
- transfusion septicemia
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For Campylobacter describe:
features
transmission
pathogenesis
associated diseases
- Features:
- G-, curved rod, motile ("darting"), very small
- microaerophilic, slow grower (needs selective campy-BAP media)
- Transmission: fecal-oral contaminant of food (esp poultry) & fluids (milk/water)
- Pathogenesis:
- infiltration of PMNs --> diarrhea, fever malaise
- Dz:
- C. jejuni = most common cause bacterial gastroenteritis in U.S. (C. coli for developing)
- associated w/ Guillain-Barre (O:19 serotype of C. jejuni)
- reactive arthritis
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For Clostridium perfringens describe:
features
transmission
pathogenesis
associated diseases
- G+ rod, spore former
- often ingest food containing toxin (type A)
- enteric infections (and gas gangrene)
- enteritis necroticans (type C)
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what species of Vibrio are known for their association with shellfish (oysters)?
- V. parahemolytics, & V. vulnificus
- explosive watery diarrhea
- is invasive, but not severe illness like V. cholerae
-
how does food poisoning occur? what's the onset? Name & describe the bacteria associated w/food poisoning.
- Occurs via ingestion of pre-formed toxins
- quick onset
- S. aureus:
- G+ cocci, cat +, coag+, mannitol fermenter, likes salt
- contaminate meat/dairy
- enterotoxins = Superantigens (T cell polyclonal activator based on binding to particular Vbeta families of T cell receptor)
- heat stabile
- Bacillus cereus:
- G+ rod, spore former
- emetic: heat stabile enterotoxin--fried rice
- diarrheal: heat labile enterotoxin meat/veggies
- Clostidium perfringens:
- meat/poultry; Sxs 8-16hrs post ingest (longer than B cereus or S. aureus)
- Clostridium botulinum:
- G+ rod, spore former, anaerobic
- AB toxin: B-binds motor neurons, A prevents release of aCh = flaccid paralysis
- droopy eyelids, blurred vision, difficulty swallowing, slurred speech, arm/leg weakness
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describe features of Primary Bacterial Peritonitis
- often due to enteric Gram-bacteria (E. coli in ~50% of the cases and Klebsiella – 10%), Streptococcus pneumonia and Group A streps (~15-20% of cases)., or anaerobic/microaerophilic organisms (5%)
- ascites
- often associated with liver disease (due to alcoholism, chronic hepatitis, liver cancer, or lupus).
- Complement proteins are lower in ascites and the neutrophils do not work well (even though they are present in the ascites)
- if >250-300 PMNs/ml of ascites = PBP
- fever almost always present
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describe 2ndary peritonitis
- peritonitis secondary to intra-abdominal disease (trauma, appendicitis, etc)
- polymicrobic – anaerobes (Bacterioides fragilis) and aerobes (E. coli, Proteus, Klebsiella, various streptococci)
- -sepsis and endotoxin-mediated pathology
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describe tertiary peritonitis
- pt w/peritoneal dialysis (continuous ambulatory peritoneal dialysis, CAPD)
- fever, leukocytosis, bacteria or fungi from the effluent fluid monomicrobial, often due to skin microbes (Staphylococcus, Pseudomonas, Candida, etc)
-
what is most comon cause of intra-abd abscesses? describe the types.
- mostly due to unTx peritonitis; associated w/ appendicitis & abd surgery
- intraperitoneal (most common):
- due to microbe AND host response
- plymicrobial
- mostly Bacteroides fragilis (anaerobe) & other enteric flora
- visceral:
- poly microbial (often liver)
- enteric G-, fungi (cancer chemoTx)
- splee abscesses--often from Streps, then S. aureus after bacterial endocarditis
- perinephric/renal abscesses: following UTI; Ecoli, Proteus, Klebsiella
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describe features of the Enterovirus, Picornaviridae.
- +ssRNA, naked icosahedral
- includes:
- Poliovirus:
- infect GI, spread to lymph, then blood, then CNS
- Enterovirus:
- non-specific febrile illness, assoc w/aseptic meningitis
- also, pneumonia, hand-food, mouth (CoxsackieA16 & Entero71)
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describe features of HCV
- Hepacivirus (Flaviviridae)
- enveloped, +ssRNA
- interrupts apoptotic signals = survival of infected cells -->persistent infection
- usually becomes chronic --> cirrhosis & primary HCC
- ELISA for anti-HCV abs; PCR for HCV RNA
-
describe features of HDV
- -ssRNA, circular
- is 'defective' b/c needs co-infection w/HBV to use HBsAg
- 40% will progress to fulminant hepatitis
-
describe HEV features
- Hepeviridae, +ssRNA virus
- fatality rate is low ecept pregos
- no vaccine
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name and describe the features of the dsDNA enveloped virus of the Herpesviridae family. describe it's pathogenesis.
- Epstein-Barr Virus (EBV aka HHV-4)
- linear genome that circulizes in host (replicate via rolling circle)
- obtains envelope from nucleus (v.s. membrane)
- latency is important
- Patho:
- mostly due to host immune response
- replicates in Bcells & epithelial cells
- stim B cell prolif & non-specific ab secretion (= heterophile ab's)
- ---->IgM isotype may cross-react to sheep/beef RBCs, ampicillin (can cause rash)
- infected B cells may progress to B cell llympoma (Burkitt's)
- CD8+ T cells become activated
-
what member of Herpesviridae causes heterophile (-) mono?
CMV
-
what motile protozoa causes dysentery w/o extra-intestinal infection?
- Balantidium coli
- relatively large, kidney-bean shaped nucleus
-
describe features of Crptosporidium infection
- C. hominis, non motile
- prob for immunosuppressed
- watery D
- acid-fast stain to detect parasite
-
what is Isospora belli? what does it cause? How is it identified?
- = non-motile protozoan, opportunistic
- self-limited D in immunocompetent
- severe in immune-compromised
- possible Hemorrhagic colitis in AIDS
- Dx via oocysts in stool or UV autofluroescence is rapid & sensitive
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what is considered the "human" tapeworm?
- Taenia saginata and T. solium:
- humans are definitive host
- cattle & pigs = intermediate
- cattle & pigs ingest eggs from human stool, larva hatch & move to mm
- humans eat undercooked meat --> worms mature & release eggs
- infection often aSxic, but larvae can develop in mm, brain, eye causing life-threatening infections
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what is considered "fish tapeworm"?
- Diphyllobothrium latum:
- Humans get infected by eating raw/undercooked fish infected by the worm.
- most aSx, heavyinfections can-->anemia b/c the worm absorbs vitamin B12
- Fish from the Great Lakes, Pacific coast, and salmon (sashimi) have been linked to infection by this worm
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name & describe the "dog" tapeworm.
- Echinoccoccus granulosus:
- Humans can be intermediate host, where the larvae can developinto a hydatid cyst in various organs.
- The normallife cycle is where dogs serve as the definitive host and sheep are theintermediate host.
- The hydatid cyst can develop in a variety of organs, including the liver, CNS, lungs, etc
-
what "fluke" is associated with veins near intestines or bladder?
- Schistosoma:
- adult female lives w/in groove in male
- humans are definitive host
- some eggs can get swept up blood to liver --> granuloma
-
what adult "fluke" can be found in hepatic bile duct?
- Fasciola hepatica:
- eggs released in stool --> water --> snail --> 'water plant'
- -->human ingests
- serologic testing or operculated eggs in stool
- Clonorchis sinensis "chinese liver fluke":
- from eating undercooked fish
- inflammatory rxn to eggs can cause granuloma
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what types of worms migrate b/w lungs & intestines? describe them.
- Ascaris lumbricoides:
- thick shell ingested, larvae burry through intestine
- -->blood --> lungs -->burrow/cough -->swallowed
- develop into adults
- heavy infections can cause:
- 2ndary bacterial infection in lungs
- intestinal rupture (adults can be up to 1ft long)
- Strongyloids stercoralis "threadworm":
- penetrate skin --> lungs, swallow --> intestines
- sometimes penetrate intestinal mucosa
- --> hyperinfection (autoinfection) esp in corticosteroid users
- -->-->pneumonia &/or diarrhea
- Dx: ID rhabditiform larvae
- Hookworms (N. americanus, A. duodenales):
- like Stronglyloides
- attach to intestine & take blood
- A. duodenales more likely cause anemia
- smooth cell, easy to view larvae
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For Ciprofloxacin describe:
MOA
Uses
SE
- MOA:
- rapid concentration-dependent killing by inhibiting DNA gyrase of GNRs; potent post-antibiotic effect
- Uses:
- Infectious diarrhea (Salmonella, Shigella, Campylobacter, E. coli (NOT shiga-toxin strains), Cholera, Yersiniosis)
- Intra-abd infections: (SBP prophylax, community-aquired complicated extra-biliary infections w/metronidazole; severe/complicated cholecystiti/cholangitis
- **don't use Quinolones for E. coli unless hospital survey indicate >90% susceptibilty
- SE:
- pseudomemb. colitis
- hypersensitivity
- theophylline toxicity
- HA, dizzy
- achilles tendon rupture
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For Moxifloxacin describe:
MOA
Uses
SE
- MOA:
- inhibit DNA gyrase of GNRs
- uses:
- mild-mod intra-abd extra-biliary infections
- SE:
- rare QT-prolongation
-
For Ceftriaxone describe:
MOA
Uses
SE
- MOA:
- 3rd gen ceph.
- bind & inhibit penicillin-binding proteins to inhibit cell-wall syntehsis
- -->bactericidal vs actively growing bacteria
- Uses:
- Diarreah: salmonella (typhoid), severe yersiniosis
- Intra-abd (SBP, mild-mod community cholecystitis, mild-mod complicated intra-abd infection w/metronidazole)
- SE:
- Pseudomembranous colitis
- hypersensitivity
- biliary stasis (prolonged use)
- bone marrow suppression (rare)
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For Azithromycin describe:
MOA
Uses
SE
- MOA:
- bacteriostatic; reversibly bind 50S --> inhibit protein synthesis
- does NOT get to brain/CSF
- Uses:
- Diarrhea (salmonella (typh), campylo, Ecoli (Not STtype), cholera)
- SE:
- none listed
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For Trimethoprim-sulfamethoxazole describe:
MOA
Uses
SE
- MOA:
- Sequential blockage of enzymatic pathway for synthesis of THF
- Uses:
- infectious diarrhea (isosporiasis, severe yerinia, NOT for shigella b/c resistance)
- intra-abd: SBP prophylaxis
- SE:
- rash
-
For doxycycline describe:
MOA
Uses
SE
- MOA:
- bind to 30S & prevent access of aminoacyl tRNA to acceptor site on mRNA-ribosome complex; bacteriostatic
- Uses:
- diarrhea of cholera
- or yersinia (w/gentamicin)
- SE:
- photosensitivity
-
For Metronidazole/tinidazole describe:
MOA
Uses
SE
- MOA:
- accepts e-s to cause toxic free-radicals that damage anaerobic & microaerophilic DNA & biomolecules
- [ ]'s well in tissues, esp. pus & liver abscesses
- Uses:
- diarrhea: (abx associated C. diff, trohpozoids, giardia)
- intra-abd: (amebic liver abscess, community acquired complicated extra-biliar infections w/cef, or cipro;)
- SE:
- peripheral sensory neuropathy
- disulfiram-like rxn
- HA
- metalic taste or nausea
-
For Nitazoxanide describe:
MOA
Uses
SE
- MOA:
- unk, maybe interfere w/PFOR enzyme-dependent e- transfer rxn
- Use:
- diarrhea: crypto, abx C. diff, giardia
- SE:
- none listed
-
For Vancomycin describe:
MOA
Uses
SE
- MOA:
- inhibit cell wall synthesis by high affinity binding to D-alanyl-D-alanine terminus of cell wall precursor unites
- Uses: severe abx-associated C. diff
- SE: o
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For Paromomycin describe:
MOA
Uses
SE
- MOA:
- bind 30S robosomal unit
- Use:
- acts v.s. amebic cysts
- giardia
-
For Piperacillin-tazobactam describe:
MOA
Uses
SE
- MOA:
- cidal vs actively growing; bind & inhibit penicillin-bindig proteins to inhibit cell wall synthesis
- Uses:
- comm-aquired intra-abd biliary AND extra-biliary infections w/ high risk or severity
- healthcare-associated biliary infection of any severity
- SE:
- volume overload
- impaired platelet aggrgtn
- hypersensitivity
- bone marrow suppression
- pseudomembranous colitis
- hepatitis (rare)
-
For Cefoxitin describe:
MOA
Uses
SE
- MOA:
- cidal vs active growing; bind & inhibit penicillin-binding proteins
- Uses:
- mild-mod comm-aquired intra-abd extra-biliary infections
- SE:
- hypersens
- bmsuppression
- pseudomembranous coloitis
-
For Aztreonam describe:
MOA
Uses
SE
- MOA:
- interacts w/pen-binding proteins & induces formation of long filamentous bacterial structures; resistant to many beta-lactamases; ONLY active vs G-'s
- Uses:
- 2ndary peritonitis (w/metronidazole & agent for G+cocci)
- Pyogenic liver abscess ("")
- Chelecystitis/cholangitis ("")
- Pancreatic abscess ("")
- SE:
- hypersensitivity but little cross-rxn if beta-lactam allergic (except ceftazidime)
-
For Carbapenems describe:
MOA
Uses
SE
- MOA:
- bind pen-binding proteins
- Uses:
- mild-mod comm-acquired intra-abd infections (ertapenem)
- high risk or severe (others)
- SE:
- hypersens (esp. crossrxn if beta-lactam allergic)
- Sz's (imi>mero)
-
For Lamivudine describe:
MOA
Uses
SE
- MOA:
- nucleoside analog that may inhibit HBV dna polymerase
- absorbed rapidly & highly available
- Uses:
- HBV infection
- SE:
- neutropenia
- discontin. can cause reboud replication & exacerbation of hepatitis
- HA, N
-
For Tenofir describe:
MOA
Uses
SE
- MOA:
- prodrug metabolized several times before active as a competitive inhibitor of viral reverse transcriptase but low affinity for human DNA polymerases
- high fat meal increases bioavalability (only to 39%)
- only need 1daily dose
- Uses:
- HBV
- SE:
- flatulence
- discont. --> rebound replication & hepatitis exacerbation
-
For Entecavir describe:
MOA
Uses
SE
- MOA:
- guanosine analogue polymerase inhibitor of HBV dna polymerase
- efficacy decreased by food
- Uses:
- HBV
- SE:
-
what medications are indicated in only for HBV infection?
-
For Adefovir describe:
MOA
Uses
SE
- MOA:
- metabolized to a competitive inhibitor of viral DNA polymerases & reverse transcriptases w/respect to deoxyadenosine
- Uses:
- HBV
-
For Ribavirin describe:
MOA
Uses
SE
- MOA:
- interferes w/synthesis of GTP, thus nucleic acids
- carried in RBC's
- Uses: HBV, HCV
- SE:
- hemolytic anemia
- teratogenicity & fetal death
- rash
- cough
- mild lymphopenia
-
For Interferon alpha describe:
MOA
Uses
SE
- MOA:
- activate JAK-STAT signal transductino pathway --> nuclear translocation of cellular protein complex that binds to genes containg IFN-specific element
- -->inhibition of protein synthesis
- increase activity of 2-5synthetase (used as marker for activity)
- Uses: HBV, HCV
- SE:
- flu-like sx
- fatigue, depression or severe mental illness
- cytopenia
- rashes
- autoimmune thyroiditis
- autoimmune hepatitis
-
For Abendazole describe:
MOA
Uses
SE
- MOA:
- inhibit microtubule polymerization by binding to beta-tubulin
- variably absorbed; enhanced by fatty meals
- Uses:
- Nematodes:
- ~Helminths
- --ascariasis
- --T. canis
- --Tichuriasis
- --Hookworms
- --Enterobiasis
- ~Trichinosis
- Cestodes
- ~echinococcosis
- ~taenia solium
- SE: mild GI
-
For Mebendazole describe:
MOA
Uses
SE
- MOA:
- inhibit microtubule polymerization by binding to beta-tubulin
- bad bioavail & 95% protein bound
- Uses:
- Nematodes (ascar, trichur, hooks, enterobiasis, trichinosis)
- SE: mild GI
-
For Pyrantel pamoate describe:
MOA
Uses
SE
- MOA:
- depolarizing neuromuscular blocking agent; opens nonselevtive cation channels & induces activatio of nivotinic aCh receptors causing spastic paralysis; also inhibits cholinesterases
- poorly absorbed
- Uses:
- ascariasis, hookworms, enterobiasis
- SE: mild GI
-
For Ivermectin describe:
MOA
Uses
SE
- MOA:
- binds blutamate-activated Cl- channels in nematode nn/mm
- Uses:
- strongyloidiasis
- SE:
- Mazzotti-like rxns
-
For Praziquantel describe:
MOA
Uses
SE
- MOA:
- lower [ ]'s induce spastic paralysis so orms detach
- higher [ ]'s induces tegumental damage leading to influx Ca2+ across tegument
- Uses:
- Cestodes:
- Intestinal form of Taenia solium (pork tapeworm)
- Taenia saginata (beef tapeworm)
- Diphyllobothrium latum (fish tapeworm)
- Hymenolepis nana (dwarf tapeworm)
- Trematodes:
- Schistosomiasis (blood flukes)
- Clonorchis sinensis, Opisthorchis viverrini, O. felineus (Chinese liver flukes)
- Fasciolopsis buski, Heterophyes heterophyes, Metagonimus yokogawai, Nanophyetus salmincola
- SE:
- mild abd discomfort
-
For Triclabendazole describe:
MOA
Uses
SE
- MOA:
- active sulfoxide metabolite binds to fluke tubulin & disrupts microtubule-based processes
- rapidly absorbed, enhanced w/food
- Uses:Trematodes
- Fasciola hepatica (liver fluke)
- Paragonimus westermani
(lung fluke)
-
name drugs that can be indicated in infectious diarrhea. which covers the most organisms? what's its' MOA?
- ciprofloxacin--inhibits DNA gyrase of GNRs
- --salmonella, shigella, camp, E. coli (except ST-type), cholera, yersiniosis
- ceftriaxone
- azithromycin
- TMP-SMX
- Doxycycline
- Metro/ti-nidazole
- nitazoxanide
- vancomycin
- paromycin
-
name drugs used for SBP prophylaxis or Tx.
- prophylaxis:
- Ciprofloxacin
- TMP-SMX
- Tx:
- ceftriaxone
-
name drugs that can Tx cholera
- ciprofloxacin
- azythromycin
- doxycycline
-
what Rx covers cryptosporidiosis? what does it also cover? what's its MOA?
- Nitazoxanide
- also abx ass. C. diff & giardia
- unclear mech, but may interfere w/PFOR e- transfer
-
what Rx can treat C. diff? specific for severe illness?
- Metronidazole/tinidazole
- nitazoxanide
- Vancomycin for severe C. diff
-
list drugs used for giardiasis
- metronidazole/tinidazole
- nitazoxanide
- paromycin
-
name drugs that can be used for BOTH HBV and HCV infections
-
what drug(s) cover strongyloidia?
Ivermectin (Ivan-strong)
-
what is the drug(s) that cover BOTH nematodes & cestodes?
Albendazole (I'll bend to tape the todes together)
covers echinococcosis, cysticercosis
-
what drug covers tapeworms and flukes?
Praziquantel ("can't tell" if tape or fluke)
-
what drug covers lung and liver flukes, but not blood flukes or tape worms?
Triclabendazole
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