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133 Cards in this Set
- Front
- Back
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Exotoxin
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Secreted from cell as polypeptide.
Genes in plasmid or bacteriophage High toxicity w/ low doses Induces high-titer antibodies called antitoxin. toxoids used as vaccine destroyed rapidly at 60C (except for staph enterotoxin) e.g.Tetanus, botulism, diphtheria |
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Endotoxin
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Outer cell membrane of most G neg and Listeria
Lipopolysaccharide Genes on bacterial chromosome. Low toxicity need high dose. Fever, shock via TNF and IL-1 Poorly antigenic No toxoids formed and no vaccine available. Stable at 100C for 1 hour e.g. meningococcemia, sepsis by G- rods. |
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Superantigen
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Binds MHC II and TCR simultaneously, activating T cells to produce IL-1 and IFNg
S. aureus - TSST-1 S. pyogenes - scarlet fever, erythrogenic toxin - TSS-like syndrome |
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ADP-ribosylating A-B toxin
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B component binds to receptor on host cell, enabling endocytosis, then A component attactes ADP-ribosyl to host cell protein, altering function.
C. diptheriae - inactivates elongation factor 2 V. cholerae -ADP ribosylates G protein to stimulate adenylyl cyclase. increase Cl- into gut, decreased Na absorption E. coli - Heat labile - adenylate cyclase; Heat stable - Guanylate cyclase. watery diarrhea. B. pertussis - increases cAMP by inhibiting Gai, whooping cough. inhibits chemockine receptor, causing lymphocytosis. |
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C. perfringens
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alpha toxin causes gas gangrene
double layer hemolysis on blood agar |
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C. tetani
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blocks release of inhibitory neurotransmitters GABA and glycine. causes lockjaw.
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C. botulinum
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blocks release of acetylcholine; causes anticholinergic symptoms, CNS paralysis, floppy baby
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B anthracis
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toxin is adenylate cyclase
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Shigella
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Shiga toxin cleaves host cell rRNA, enhances cytokine release, causing HUS (hemolytic anemia, renal failure, thrombocytopenia)
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S. pyogenes
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Streptolysin O is hemolysin, antigen for ASO antibody used in Dx of rheumatic fever
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H influenzae mediea
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Chocolate agar w/ factors V (NAD) and X (hematin)
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N. gonorrhea media
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Thayer-Martin media
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B. pertussis media
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Bordet-Gengou (potato) agar
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C. diphtheriae media
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Tellurite plate, Loffler's media
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M. tuberculosis media
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Lowenstein-Jensin agar
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Lactose-fermenting enterics
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Pink colonies on MacConkey's agar
Klebsiella, E. coli, Enterobacter, Citrobacter |
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Legionella media
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Charcoal yeast extract agar buffered with increased iron and cysteine
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Fungi media
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Sabourad's agar
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Giemsa's stain
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Borrelia
Plasmodium Trypanosomes Chlamydia |
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PAS stain
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stains glycogen, mucopolysaccharides, used to diagnose Whipple's disease
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Ziehl-Neelsen stain
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acid fast bacteria
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India ink stain
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Cryptococcus neoformans
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Silver stain
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Fungi, Legionella
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Bacteria with toxins encoded in a lysogenic phage
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Shig-A-like toxin
Botulinum toxin Cholera toxin Diphtheria toxin Erythrogenic toxin (S pyogenes) = ABCDE |
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Facultative intracellular bugs
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Salmonella
Neisseria Brucella Mycobacterium Listeria Francisella Legionella Yersinia Some Nasty Bugs May Live FacultativeLY |
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Urease positive
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H pylori
Proteus Klebsiella Ureaplasma |
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Neisseria
gonococci vs menigitides |
Both Gram neg cocci, ferment glucose and produce IgA protease
Gonococci- no capsule, no maltose formation, no vaccine, STD, causes gonorrhea, septic arthritis, neonatal conjuctivitis, PID Meningococci - polysaccharide capsule, maltose fermentation, vaccine, respiratory and oral secretions, causes meningococcemia and meningitis, Waterhouse-Fridrichsen syndrome |
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Enterobacteriaceae
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E. coli, Salmonella, Shigella, Klebsiella, Enterobacter, Serratia, Proteus
Capsular (K) O antigen (polysaccharide of endotoxin) Flagellar antigen (H) Ferment glucose |
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Causes of Food poisoning
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Vibrio parahaemolyticus - seafood
V. vulnificus - seafood, water, shellfish B. cereus - reheated rice S. aureus - meats, mayo, custard C. perfringens - meat dishes C. botulinism - canned food E. coli O157H7 - undercooked meat Salmonella- poultry, meat, eggs S. aureus and B cerues poisoning starts early and ends early. |
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Bloody Diarrhea
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Camplyobacter - comma or S shaped organisms, grow at 42C, oxidase positive
Salmonella Shigella EHEC - Shiga toxin EIEC - enteroinvasive Yersinea enterocolitica C. diff E. histolytica |
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Watery diarrhea
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ETEC - traveler's diarrhea - ST and LT
V. cholerae C. perfringens Protozoa - Giardia, Cryptosporidium Viruses - rotavirus, adenovirus, norwalk |
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Enterobius vermicularis
pinworm |
Food contaminated with eggs, intestinal infxn, causes anal pruritis, do Scotch tape test.
Rx - mebendazole/ pyrantel pamoate |
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Ascaris lumbricoides
giant roundworm |
Eggs are visible in feces, intestinal infxn
Rx - mebendazole, pyrantel pamoate |
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Trichinella spiralis
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Undercooked meat, usually pork; inflammation of muscle (larvae encyst in mm), periorbital edema
Rx - thiabendazole |
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Strongyloids stercoralis
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larvae in soil penetrate skin; intestinal infxn, causes vomiting, diarrhea, anemia
Rx - Ivermectin/thiabendazole |
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Ancylostoma duodenale
Necator americanus hookworms |
Larvae penetrate skin of feet, intestinal infxn causes vomiting, diarrhea, anemia
Rx - Mebendazole/ prantel pamoate |
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Dracunculus medinensis
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In drinking water, skin inflammation and ulceration
Rx - niridazole |
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Onchocerca volvus
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Transmitted by female blackflies; causes river blindness, with skin nodules and lizard skin. can have allergic rxn to microfilaria
Rx - ivermectin |
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Loa loa
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transmitted by deer fly, horse fly and mango fly; causes swelling in skin, can see worm crawling in conjunctiva
Rx - diethylcarbamazine |
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Wuchereria bancrofti
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female mosquito. causes blockage of lymphatic vessels - elephantiasis
Rx - diethylcarbamazine |
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Toxocaria canis
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Food contaminated with eggs; causes granulomas, if in retina causes blindness, and visceral larva migrans
Rx - diethylcarbamazine |
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Taenia solium
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tapeworm. ingestion of larvae encysted in undercooked pork leads to intestinal tapeworms. ingestion of eggs cause cysticercosis and neurocysticercosis, mass lesions in brain. swiss cheese appearance.
Rx - praziquantel for intestinal worms and cysticercosis; albendazole for neurocysticercosis |
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Echinococcus granulosus
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Tapeworm. Eggs in dog feces when ingested can cause cysts in liver. causes anaphylaxis if echinococcal antigens are released from cysts
Rx - albendazole |
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Schistosoma
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Trematodes. Snails are host. cercariae penetrate skin of humans, cause granulomas, fibrosis and inflamm of spleen and liver.
S. mansoni - portal HTN S. haematobium - hematuria, bladder cancer. Rx - Praziquantel. |
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Clonorchis sinensis
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Undercooked fish; causes inflammation of the biliary tract to create pigmented gallstones. Also assoc w/ cholangiocarcinoma.
Rx - praziquantel |
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Paragonimus westermani
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Tapeworm. Undercooked crab meat; causes inflammation and 2ndry bacterial infxn of lung. Hemoptysis.
Rx - praziquantel |
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Nonenveloped Viruses
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Calcivirus
Picornavirus Reovirus Parvovirus Adenovirus Papilloma Polyoma CPR PAPP |
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DNA enveloped viruses
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Herpesviruses - HSV, VZV, CMV, EBV
HBV smallpox |
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DNA nucleocapsid
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Adenovirus
Papillomaviruses Parvovirus |
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RNA enveloped viruses
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Influenza virus, parainfluenza virus, RSV, measles, mumps, rubella, rabies, HTLV, HIV
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RNA nucleocapsid
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Enterovirus - polio, coxsackie, echo, HAV
Rhinovirus Reovirus - rotavirus |
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live attenuated vaccines
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measles
mumps rubella Sabin polio VZV yellow fever smallpox |
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Killed vaccines
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Rabies
Influenza Salk Polio HAV |
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Recombinant vaccines
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HBV (HBsAg)
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negative-stranded RNA viruses
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Arenaviruses
Bunyaviruses Paramyxoviruses Orthomycoviruses Filoviruses Rhabdoviruses Hepatitis delta virus |
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Segmented viruses
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all RNA.
Bunyaviruses Orthomyxovirus (influenza) Arenaviruses Reoviruses |
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HSV-1
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Gingivostomatitis, keratoconjuctivitis, temporal lobe encephalitis, herpes labialis
Transmitted respiratory secretions, saliva |
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HSV-2
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Herpes genitalis, neonatal herpes
transmitted sexually, perinatal |
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VZV
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Varicella zoster (shingles), encephalitis, pneumonia
transmitted via respiratory secretion |
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EBV
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Infectious mononucleosis, Burkitt's lymphoma
Transmitted respiratory secretions, saliva |
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CMV
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Congenital infxn, mononucleosis (negative monospot), pneumonia. owl's eye cells.
Transmitted - congenital, transfusion, sexual contact, saliva, urine, transplant |
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HHV-8
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Kaposi's sarcoma
Transmitted sexually |
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HAV
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RNA picornavirus
fecal oral transmission Short incubation - 3 weeks No carriers Asymptomatic, Acute, Alone |
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HBV
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DNA hepadnavirus
parenteral, sexual, maternal-fetal routs. long incubation - 3 months Carriers. Cell RNA polymerase transcribes RNA from DNA template, then reverse trancriptase transcribes DNA genome from RNA intermediate. virion is DNA-dependent DNA polymerase |
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HCV
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RNA flavivirus. blood transmission, resembles HBV in course and severity. Carriers. Common cause of Hepatitis among IV drug users.
Chronic, Cirrhosis, Carcinoma, Carriers |
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HDV
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delta agent. Defective virus hat requires HBsAg as its envelope. HDV can coinfect w/ HBV or superinfect. latter has worse prognosis. Carriers.
Defective, Dependent on HBV |
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HEV
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RNA calicivirus transmitted enterically and causes water-borne epidemics. Resembles HAV in course, severity, incubation. High mortality rate in pregnant women.
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Pneumonia
Neonates < 4 wks |
Group B strep
E. coli |
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Pneumonia
Children (4 wk - 18 yrs) |
Viruses - RSV
Mycoplasma Chlamydia pneumoniae Strep pneumoniae Runts May Cough Sputum |
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Pneumonia
Adults (18-40yrs) |
mycoplasma
C. pneumoniae S. pneumoniae |
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Pneumonia
Adults (40- 65) |
S. pneumoniae
H. influenzae Anaerobes Viruses Mycoplasma |
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Pneumonia
Elderly |
S. pneumoniae
Viruses Anaerobes H. influenzae Gram negative rods |
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Meningitis in the newborn (< 6 mo)
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Group B Strep
E. coli Listeria |
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Meningitis in children ( 6 mo - 6 yrs)
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Strep pneumoniae
N. meningitides H. influenzae type B Enteroviruses |
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Meningitis 6 yrs- 60 yrs
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N. meningitides
Enteroviruses S. pneumoniae HSV |
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Meningitides in 60+ yrs
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S. pneumoniae
G- rods Listeria |
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ToRCHeS
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Toxo - triad - chorioretinitis, intracranial calcification, hydrocephalus, may be asymptomatic at birth
Rubella - deafness, cataracts, heart defects (PDA, pulm artery stenosis), MR CMV - petechial rash, intracranial calcifications, MR, hepatosplenomegaly, microcephaly, jaundice. 90% asymptomatic. HIV - hepatosplenomegaly, neurologic abnormalities, frequent infxns HSV2 - encephalitis, conjuctivitis, vesicular lesions. aSx at birth Syphilis - cutaneous lesions, hepatosplenomegaly, jaundice, saddle nose, saber chins, Hutchinson teeth, CNVIII deafness, rhinitis |
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Bacteriostatic antibiotics
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Erythromycin
Clinadmycin Sulfamethoxazole Trimethoprim Tetracyclines Chloramphenicol |
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Bactericidal antibiotics
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Vancomycin
Fluoroquinolones Penicillin Aminoglycosides Cephalosporins Metronidazole |
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Penicillin
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G form is IV, V form is oral.
b-tactam antibiotics. Bind penicillin binding proteins, block transpeptidase cross-linking of cell wall, activate autolytic enzymes Rx - bactericidal fro G+ cocci and rods, G- cocci, spirochetes. Tox - hypersensitivity rxns, hemolytic anemia |
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Methicillin, nafcillin, dicloxacillin
penicillinase-resistant penicillins |
Same action as penicillin, narrow spectrum. resistance from bulky R group
Rx - S. aurues (except MRSA) Tox - hypersensitivity rxns, methicillin - interstitial nephritis |
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Ampicillin, amoxicillin
aminopenicillins |
Same action as penicillin. wider spectrum, penicillinase sensitive. combine w/ clavulinic acid to enhance spectrum. amoxicillin has greater oral bioavailability than ampicillin
Rx - extended spectrum penicillin, some gram+ bacteria and G- rods H. influenzae, E. coli, Listeria, Proteus, Salmonella, enterococci Tox - Hypersensitivity rxns, ampicillin rash, pseudomembranous colitis Rx - |
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Ticarcillin, carbenicillin, piperacillin
anti-pseudamonals |
b-lactam. extended spectrum
Rx - Pseudomanas, G- rods; susceptible to penicillinase, use with clavulanic acid Tox - hypersensitivity rxns |
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cefazolin, cephalexin
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b-lactams, less susceptible to penicillinases. bacteriocidal.
1st gen cephalosporins G+ cocci, Proteus, E. coli, Klebsiella pneumoniae PEK |
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Cefoxitin, cefaclor, cefuoxime
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b-lactams, less susceptible to penicillinases. bacteriocidal.
2nd gen cephalosporins G+ cocci, Haemophilus influenzae, Enterobacter aerogenes, Neisseria, Proteus, E.coli, Klebsiella, Serratia HEN PEKS |
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Ceftriaxone, cefotaxime, ceftazidime
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b-lactams, less susceptible to penicillinases. bacteriocidal.
3rd gen cephalosporin serious G- infxns resistant to other b-lactams, meningitis (penetrate BBB) |
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Cefepime
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b-lactams, less susceptible to penicillinases. bacteriocidal.
4th gen cephalosporin Increased activity against pseudomonas and G+ organisms |
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Cephalosporin tox
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Hypersensitivity rxns.
Cross Hypersensitivity in 5-10% w/ pencillin allergy. increased nephrotoxicity of aminoglycosides. disulfirum rsn w/ Etoh |
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Aztreonam
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monobactam resistant to b-lactamases. Inhibits cell wall synthesis by binding to PBP3. synergistic w/ aminoglycosides. No cross-allergenicity w/ penicillins or cephalosprins
Rx - G- rods, Klebsiella, pseudamonas, Serratia. No activity against G+ or anaerobes. Used in patients w/ renal insufficiency who cannot tolerate aminoglycosides Tox - nontoxic, GI upset |
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Imipenem/cilastatin, meropenem
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imipenem is a broad-spectrum, b-lactamase resistant carbapenem. administered w/ cilastin (inhibitor of renal dihydropeptidase I) to reduce inactivation of renal tubules
Rx - G+ cocci, G- rods, anaerobes. Drug of choice for Enterobacter. limit to use w/ life-threatening infxns after other drugs fail. Meropenem has a reduced risk of seizures and is stable to dihydropeptase I Tox - GI distress, skin rash, CNS toxicity w/ seizures at high levels |
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Vancomycin
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Inhibits cell wasll mucopeptide formation by binding D-ala, D-ala portion of cell wall precursors. Bactericidal.Resistance occurs w/ amino acid chage to D-ala L-lac
Used for serious G+ multidrug resistant organisms, including S aureus and C. diff Tox - nephrotoxicity, ototocity, thrombophlebitis = NOT, diffuse flushing "red man" prevent by pretreatment w/ antihistamines and slow infusion rate. generally well tolerated |
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Gentamicin, Neomycin, Amikacin, Tobramycin, Streptomycin
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Aminoglycosides
Bactericidal; binds to 30S inhibit formation of initiation complex and causes misreading fo mRNA. Require O2 for uptake so ineffective against anaerobes. Rx - severe gram-negative rod infections.Synergistic w/ beta-lactam antibiotics. Neomycin for bowel surgery. Tox - Nephrotoxicity (esp w/ cephalosporins), ototoxicity (w/ loop diuretic), Teratogen |
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Tetracycline, doxycycline, demeclocycline, minocycline
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Tetracyclines. bind 30S. bacteriostatic.
prevent attachment of tRNA, limited CNS penetration. Doxy fecally eliminated and can be used in pts w/ renal failure. Must not take w/ milk, antacids or iron b/c divalent caations hinibit absorption in the gut. Rx - Vibrio cholerae, Acne, Chlamydia, Ureaplasma urealyticum, Mycoplasma, Tularemia, H pylori, Borrelia bergdorferi, Rickettsia Tox - GI distress, discoloration of teeth and inhibition of bone growth in children, photosensitivity, contrainidacated in pregnancy. |
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erythromycin, azithromycin, clarithromycin
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macrolides. inhibit protein synthesis by blocking translocation; bind to the 23S rRNA of the 50S ribosomal subunit. Bacteriostatic.
Rx - URI, penumonia, STD, G+ cocci if allergic to penicillin, Mycoplasma, Legionella, Chlamydia, Neisseria Tox - GI discomfort, acute cholestatic hepatitis, eosinophilia, skin rashes, increased serum concentration of theophyllines, oral anticoagulants |
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Chloramphenicol
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Inhibits 50S peptidyltransferase activity, bacteriostatic.
Rx - meningitis (H. influenza, N. meningitides, S. pneumoniae) Tox - anemia, aplastic anemia (dose independent), gray baby syndrome in premature infants b/c they lackliver UDP-glucuronyl transferase |
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Clindamycin
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Blocks peptide bond formation at 50S ribosomal subunit. bacteriostatic.
Rx - anaerobic infxns, Bacteriodes, Clostridium Tox - pseudomembranous colitis, fever, diarrhea |
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sulfamethoxazole SMX, sulfisoxazole, triple sulfas, sulfadiazine
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Sulfonamides.
PABA metabolites inhibit dihydropteroate synthetase. Bacteriostatic. Rx - G+, G-, nocardia, chlamydia Triple sulfas or SMX for simple UTI Tox - Hypersensitivity rxn, hemolysis if G6PD deficient, nephrotoxicity (tubulointerstitial nephritis), photosensitivity, kernicterus in infants, displace other drugs from albumin (e.g. warfarin) |
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Trimethoprim
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inhibits bacterial dihydrofolate reductase. Bacteriostatic.
Used w/ sulfonamides for synergy. TMP-SMX used for recurrent UTIs, Shigella, Salmonella, Pneumocystis jiroveci pneumonia Tox - megaloblastic anemia, leukopenia, graynulocytopenia, may alleviate w/ supplemental folinic acid |
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Ciprofloxacin, norfloxacin, ofloxacin, sparfloxacin, moxiflocacin, gatifoxacin, enoxacin and nalidixic acid (quinolone)
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fluoroquinolones.
inhibit DNA gyrase topo II. Bactericidal, do not take w/ antacids. Rx - G- rods of urinary and GI tracts including Pseudomonas, neisseria, some G+ Tox - GI upset, superinfections, skin rashes, headache, dizziness. Contraindicated in pregnant women and children b/c damage to cartilage. Tendonitis and tendon rupture in adults; leg cramps and myalgias in kids |
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Metronidazole
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toxic metabolites in bacerial cell that damage DNA. bactericidal.
Rx - antiprotozaol. Giardia, Entamoeba, Trichomonas, Gardnrella vaginalis, Anaerobes. Used w/ bismuth and amoxicillin for triple therapy against H. pylori Tox - disulfiram rxn w/ alcohol; headache, metallic taste |
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Polymixins
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B, E.
bind to cell membranes of baceria and dissrupt their osmotic properties. Cationic, basic proteins that act like detergents. Rx - resistant G- infxns Tox - neurotoxicity, acute renal tubular necrosis |
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M. avium intracellularae Tx
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azithromycin, rifampin, ethambutol, streptomycin
M. leprae - dapsone, rifampin, clofazimine |
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INH
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decreased synthesis of mycolic acids
Rx - Mycobacterium tuberculosis, TB prophylaxis Tox - hemolysis if G6PD deficient, neurotoxicity, hepatotoxicity, SLE-like syndrome. Pyridoxine B6 can prevent neurotoxicity |
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Rifampin
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Inhibits DNA-dependent RNA polymerase
Rx - mycobacterium tuberculosis; delays resistance to dapsone when used for leprosy. Used for meningococcal prophylaxis and chemoprophylaxis in contact of children w/ H. influenza type B Tox - minor hepatotoxicity and drug interactions. increased p450. orange body fluids. |
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Amphotericin B
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Binds ergosterol unique to fungi, forms membrane pores that allow leakage of electrolytes.
Rx - wide spectrum of systemic mycoses, Cryptococcus, Blasto, Coccidiodes, Aspergillus, histo, candida, mucor. Intrathcally for fungal meningitis, does not cross BBB Tox - fever/chills, hypotension, nephrotoxicity, arrhythmias, anemia, IV phlebitis, Hydration reduces nephrotoxicity, liposomal amphotericin reduces toxicity |
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Nystatin
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Binds to ergosterol, disrupting fungal membranes. too toxic for systemic use.
Rx - swish and swallow for oral candidiases, topical for diaper rash or vag |
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fluconazole, keoconazole, clotrimazole, miconazole, itraconazole, voriconazole
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Azoles
inhibit fungal steroid ergosterol synthesis. Rx - systemic mycoses. fluconazole for cryptococcal meningitis in AIDS, candidal infxns, Keto conazole for Blasto, coccidioides, histoplasma, candida; hypercortisolism. Clotrimazole and miconazole for topical fungal infxns Tox - hormone synthesis inhibition - gynecomastia, liver dysfunction - inhibits cytochrome p450, fever, chills |
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Flucytosine
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inhibits DNA synthesis by conversion to fluorouracil which competes iwth uracil.
Used in systemic fungal infxns, in combination w/ amphotericin B Tox - nausea, vomiting, diarrhea, bone marrow suppresssion |
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Caspofungin
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inhibits cell wall synthesis
invasive aspergillosis Tox - GI upset, flushing |
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Terbinafine
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Inhibits fungal enzyme squalene epoxidase
Rx - treat dermatophytoses, esp onychomycosis |
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Griseofulvin
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Interferes with microtuble function, disrupts mitosis, deposits in keratin-containing tissues
Rx - oral treatment of superficial infxns, inhibits growth of dermatophytes - tinea, ringworm Tox - teratogenic, carcinogenic, confustion, headaches, increase p450 and warfarin metabolism |
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Amantadine
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Blocks viral penetration/uncoating M2 protein; may buffer pH of endosome, causes release of dopamine from intact nerve terminals.
Rx - prophylaxis and Rx for influenza A, Parkinson's Tox - ataxia, dizziness, slurred speech Resistance - mutated M2, 90% of all influenza A strains are resistant to amantidine, not used. |
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Zanamivir, oseltamivir
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inhibit influenza neuraminidase, decreasing release of progeny virus.
Rx - influenza A and B |
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Ribavirin
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inhibits synthesis of guanine nucleotides by competitively inhibiting IMP dehydrogenase
Rx - RSV, chronic hepatitis C Tox - hemolytic anemia, severe teratogen |
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Acyclovir
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monophosphorylated by HSV/VZV thymidine kinase. Triphosphate formed by cellular enzymes. preferentially inhibits viral DNA polymerase by chain termination
Rx - HSV, VZV, EBV. Used for HSV-induced mucocutaneous and genital lesions as well as for encephalitis. prophylaxis in immunocompromised patients. for herpes zoster, use famciclovir |
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Acyclovir
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Monophosphorylated by HSV/VZV thymidine kinase. Triphosphate formed by cellular enzymes. Preferentially inhibits viral DNA polymerase by chain termination.
HSV, VZV, EBV, used for HSV-induced mucocutaneous and genital lesions, encephalitis. Prophylaxis in immunocompromised patients. for herpes zoster use famciclovir. No effect on latent HSV and VZV Generally well tolerated Resistance from lack of thymidine kinase |
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Ganciclovir
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5' monophosphate formed by a CMV viral kinase or HSV/VZV thymidine kinase. Triphosphate formed by cellular kinases. Preferentially inhibits viral DNA polymerase.
Rx - CMV esp immunocompromised Tox - leukopenia, neutropenia, thrombocytopenia, renal toxicity. more toxic to host enzymes than acyclovir Resistance via mutated CMV DNA polymerase or lack of viral kinase |
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Foscarnet
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Viral DNA polymerase inhibitor that binds to pyrophosphate-binding site of enzymes, does not require activation by viral kinase.
CMV retinitis in immunocompromised pts when ganciclovir fails. acyclovir-resistant HSV Tox - nephrotoxicity resistance if mutated DNA polymerase |
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Protease inhibitors
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Saquinavir, ritonavir, indinavir, nelfinavir, amprenavir.
Inhibit assembly of new virus by blocking protease in progeny virions Tox - GI intoleranse (nausea, diarrhea), hyperglycemia, lipodystrophy, thrombocytopenia (indinavir) |
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Reverse transcriptase inhibitors
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Nucleosides - zidovudine ZDV, didanosine ddI, zalcitabine ddC, stavudine d4T, lamivudine 3Tc, abadavir
non-nucleosides - Nevirapine, Efavirenz, Delavirdine Mechanism - preferentially inhibit reverse transcriptase of HIV, prevent incorporation of DNA copy of viral genome into host DNA Tox - bone marrow suppression, neutropenia, anemia, peripheral neuropathy, lactic acidosis, nucleosides, rash (non-nucleosides), megaloblastic anemia ZDV HAART = protease inhibitors and reverse transcriptase inhibitors when low viral load or low CD4. ZDV general prophylaxis and to prevent vertical transmission (mom to baby) |
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Fusion inhibitors
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Enfuvirtide
bind viral gp41, inhibit conformational change required for fusion w/ CD4 cells. block entry and subsequent replication. Hypersensitivity rxn, rxn at subcutaneous injection site, increased risk of bacterial pneumonia. used if presistant viral replication in spite of antiretroviral therapy. used in combination with other drugs. |
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IFN
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glycoproteins from human leukocytes that block various stages of viral RNA and DNA syntheis. induce ribonuclease that degrades viral mRNA
IFNa - chronic hepatitis B,C, Kaposi's sarcoma IFNb - Ms IFNg - NADPH oxidase deficiency Tox - neutropenia |
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Antibiotics to avoid in pregnancy
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Sulfonamides - kernicterus
Aminoglycosides - ototoxicity Fluoroquinolones - cartilage damage Erythromycin - acute cholestatic hepatitis Clarithromycin - embryotoxic Metronidazole - mutagenesis Tetracyclines - discolored teeth, inhibition of bone grwoth Ribavirin - teratogenic Grisiofulvin - teratogenic Chloramphenicol - gray baby |
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Giardia lamblia
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Giardiasis - bloating, flatulence, foul-smelling diarrhea.
Often seen in campers/hikers. Transmitted by cysts in water Diagnosed by trophozoites or cysts in stool. Rx - metronidazole |
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Trichomonas vaginalis
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Vaginitis - foul-smelling, greenish discharge. itching and burning.
Sexual transmission. Trophozites on wet mount Rx - metronidazole |
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Trypanosoma cruzi
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Chagas disease - destruction of myenteric plexi of esophagus, intestines and ureters, resulting in dilated cardiomyopathy, megacolon, megaesophagus. South America.
Transmitted by Reduviid bug. Diagnosed by blood smear. Rx - nifuritimox |
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Trypanosoma
gambiense and rhodesiense |
African sleeping sickness
Tsetse fly Dx w/ blood smear Suramin for blood-borne disease or melarsoprol for CNS penetration |
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Leishmania donovani
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Visceral leishmaniasis (kala azar), spiking fevers, hepatosplenomegaly, pancytopenia
Sandfly Dx w/ macrophages containing amastigotes. Rx - sodium stibogluconate |
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Plasmodium
spp vivax, ovale, malariae, falciparum |
Malaria - cyclic fever, headache, anemia, splenomegaly.
If severe (cerebral) P. falciparum. vivax and ovale have dormant forms in liver hypnozoites, results in relapsing malaria. Anopheles mosquito. See trophozoite ring, or RBC w/ merozoites on blood smear. Rx - chloroquine w/ primiquine to preven relapse of vivax and ovale. Sulfadoxine _ pyrimethamine, mefloquine, quinine |
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Babesia
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Babesiosis - fever and hemolytic anemia. predominantly in northeastern United States.
Transmitted w/ Ixodes tick. Dx - blood smear, no RBC pigment, appears as maltese cross and ring forms. Rx - quinine, clindamycin. |
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Cryptosporidium
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Severe diarrhea in AIDS
Mild disease of watery diarrhea in non-immunocompromised. Transmiteed by cysts in water. Cysts on acid-fast stain. No treatment |
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Toxoplasma gondii
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Brain abscess in HIV, birth defects. visible as ring-enhancing brain lesions
Transmitted via cysts in meat or cat feces, crosses placenta - pregnant women should avoid cats. Dx w/ serology, biopsy Rx - Sulfadiazine + pyrimethamine |
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Entamoeba histolytica
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Amebiasis - bloody diarrhea, liver abscess, RUQ pain
Transmitted by cysts in water. Dx w/ Serology and trophozoites or cysts in stool; RBC in cytoplasm of entamoeba. Rx - metronidazole and iodoquinol |
