Microbiology- First Aid Flashcards
(192 cards)
1
Q
Bacteria that do not Gram stain well
A
Treponema, Mycobacteria, Mycoplasma, Legionella pneumophila, Rickettsia, Chlamydia
2
Q
Giemsa Stain
A
Chlamydia, borrelia, Rickettsiae, Trypanosomes, Plasmodium
3
Q
PAS Stain
A
Tropheryma whipplei
4
Q
Ziehl-Neelsen
A
Nocardia, Mycobacterium (acid fast)
5
Q
India ink
A
Crytococcus neoformans
6
Q
Silver stain
A
Legionella, Helicobacter pylori, pneumocystis
7
Q
Obligate Aerobes
A
Nocardia, Pseudomonas, Mycobacterium tuberculosis
8
Q
Obligate Anaerobes
A
Clostridium, Bacteroides, Actinomyces
9
Q
Obligate intracellular
A
Rickettsia, Chlamydia
10
Q
Facultative intracellular
A
Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, Yersinia pestis
11
Q
Encapsulated bacteria
A
Strep pneumoniae, haemophilus influenzae type B, Neisseria meningitidis, Escherichia coli, Salmonella, Klebsiella pneumoniae, group B strep
12
Q
Catalase positive
A
Pseudomonas, Listeria, Aspergillus, Candida, E.coli, S. aureus, Serratia
13
Q
Urease positive
A
Cryptococcus, H. pylori, Proteus, Ureaplasma, Nocardia, Klebsiella, Staph epidermis, Staph saprophyticus
14
Q
Pigment producing bacteria
A
Actinomyces israelii (yellow granules) Staph aureus (yellow) Pseudomonas aeruginosa (blue-green pigment) Serratia marcescens (red pigment)
15
Q
Effects of endotoxin (lipid A- mediated)
A
fever, hypotension, edema, neutrophil, chemotaxis, DIC
16
Q
Toxins whose genes are encoded by a phage
A
shiga-like toxin, botulinum, cholera, diptheria, erythrogenic toxin (strep pyogenes)
17
Q
Novobiocin
A
Staph Epidermidis is sensitive; Staph saprophyticus is resistant
18
Q
Optochin
A
Strep viridans is resistant; strep pneumoniae is sensitive
19
Q
Bacitracin
A
group B strep (agalactiae) are resistant; group A strep (pyogenes) are sensitive
Both group A and group B are beta-hemolytic
20
Q
Staph epidermidis
A
infects prosthetic devices and IV catheters by producing adherent biofilms
21
Q
Staph saprophyticus
A
2nd leading cause of uncomplicated UTI
22
Q
Strep pneumoniae
A
meningitis, otitis media, pneumonia, sinusitis, alpha-hemolytic
23
Q
Viridans group streptococci
A
Strep mutans- dental caries
Strep sanguinis- subacute bacterial endocarditis
24
Q
Strep pyogenes
A
pharyngitis, cellulitis, impetigo, scarlet fever, toxic shock-like syndrome, necrotizing fasciitis, rheumatic fever, acute glomerulonephritis
25
Jones criteria for rheumatic fever
polyarthritis, carditis, subq nodules, erythema marginatum, sydenham chorea
26
Scarlet Fever
scarlet rash with sandpaper-like texture, strawberry tongue, circumoral pallor
27
Strep agalactiae
colonizes vagina causing pneumonia, meningitis, and sepsis in neonates
28
Enterococcus faecalis and faecium
penicillin G resistant, UTI, biliary tract infections, subacute endocarditis (post-GU/GI procedures)
29
Strep bovis
colonizes the gut, can cause bacteremia and subacute endocarditis in colon cancer patients
30
Corynebacterium diphtheriae
AB exotoxin ADP-ribosylates EF-2
| Symptoms include pseudomembranous pharyngitis with lymphadenopathy, myocarditis, and arrhythmias
31
Spore-forming bacteria
Bacillus anthracis, Clostridium perfringens, Clostridium tetani, Bacilus cereus, Clostridium botulinum, Coxiella burnetii
32
Anthrax
Bacillus anthracis, a gram + spore-forming rod that is the only bacterium that contains a polypeptide capsule
33
Cutaneous anthrax
boil-like lesion--> ulcer with black eschar
34
Pulmonary anthrax
inhalation of spores--> flu-like symptoms that rapidly progress to fever, pulmonary hemorrhage, mediastinitis, and shock
35
Bacillus cereus
nausea and vomiting, watery nonbloody diarrhea, reheated rice syndrome
36
Listeria monocytogenes
- acquired by ingestion of unpasteurized dairy products and deli meats, via transplacental trasmission, or by vaginal transmission during birth
- only gram + to produce LPS
- causes amnionitis, septicemia, spontaneous abortion, granulomatosis infantiseptica, neonatal meningitis, meningitis in immunocompromised patients, mild gastroenteritis
37
Types of mycobacteria and their findings
Tuberculosis- TB
Kansassi- pulmonary TB like symptoms
Avium-intracellulare- disseminated non TB disease in AIDS
38
TB symptoms
fever, night sweats, weight loss, and hemoptysis
39
Lepromatous M. Leprae
diffuse infection over skin, leonine facies, communicable, humoral Th2 response
40
Tuberculoid M. Leprae
limited to a few hypoesthetic hairless skin plaques, characterized by cell-mediated Th1- type response
41
Lactose-fermenting enteric bacteria
Citrobacter, Klebsiella, E.coli, Enterobacter, Serratia
42
Haemophilus influenzae
Epiglottitis, meningitis, otitis media, pneumonia
43
H. influenzae culture
Chocolate agar with factor V (NAD+) and X (hematin)
44
Legionella pneumophila
- Gram negative rod
- Grows on charcoal yeast extract culture with iron and cysteine
- Aerosol transmission from environmental water source
- Severe pneumonia, fever, GI and CNS symptoms (Legionnaires' disease)
- mild flu-like syndrome (Pontiac fever)
45
Hemolytic uremia syndrome
anemia, thrombocytopenia, acute renal failure
46
Klebsiella
- Intestinal flora that causes lobar pneumonia in alcoholics and diabetics when aspirated
- red currant jelly sputum
- gram negative lactose fermenting rods
47
Salmonella typhi
- Typhoid fever
- Rose spots on abdomen, fever, headache, and diarrhea
- Remain in gallbadder (carrier state)
48
Campylobacter jejuni
- oxidase positive
- bloody diarrhea
- fecal oral transmission
- common antecedent to Guillain-Barre syndrome and reactive arthritis
49
Vibrio Cholera
- oxidase positive
- comma shaped
- rice water diarrhea that activates Gs (increases cAMP)
50
Yersinia enterocolitica
- transmitted from pet feces, contaminated milk, pork
| - mesenteric adenitis that can mimic Crohn disease or appendicitis
51
Helicobacter pylori
- gastritis and peptic ulcers (especially duodenal)
- curved rod that is catalase, oxidase and urease positive
- triple therapy: PPI, clarithromycin, amoxicillin or metronidazole
52
Spirochetes
Borrelia (biggest), Leptospira, Treponema
53
Leptospira interrogans
- transmitted by water contamination of animal urine
- leptospirosis: flu-like, jaundice, photophobia with conjunctival erythema without exudate
- Weil disease: severe form with jaundice, azotemia, fever, hemmorhage, and anemia
54
Lyme disease
- Borrelia burgdorferi
- Ixodes tick
- Initial symptoms: erythema migrans, flu-like symptoms, facial nerve palsy
- monoarthritis, migratory polyarthritis, AV nodal block, encephalopathy, facial nerve palsy, polyneuropathy
- doxycycline ceftriaxone
55
VDRL false positives
mononucleosis, EBV, hepatitis, drugs, SLE, leprosy
56
Jarisch-Herxheimer
flu-like syndrome after abx are started due to killed bacteria releasing pyrogens
57
Gardnerella vaginalis
- vaginosis (fishy smell of vagina, nonpainful, associated with sexual activity)
- vaginal epithelial cells covered with gardnerella
- tx metronidazole, clindamycin
58
Rickettsia rickettsii
- tick vector
- Rocky mountain spotted fever
- rash starts in palms and soles, spreads to trunk, palms, and soles
- headache, fever, rash
59
Rickettsia typhi/prowazekii
-rash starts centrally and spreads out, spares palms and soles
60
Ehrlichia chaffeenis
- tick vector
- Ehrlichiosis
- monocytes with morulae (berry like inclusions in the cytoplasm)
61
Anaplasma
- tick vector
- granulocytes with morulae in cytoplasm
- Anaplasmosis
62
Coxiella burnetii
- spores inhaled as aerosol
- pneumonia
- no rash
63
Mycoplasma pneumoniae
- pneumonia (insidious onset, headache, nonproductive cough, patchy or diffuse interstitial infiltrate)
- grown on Eaton agar
- IgM
- Tx, macrolide, doxycycline, fluoroquinolone
64
Systemic mycoses
- pneumonia
- dimorphic (mold in cold, yeast in heat)
- tx is fluconazole or itraconzaole for local infection and amphotericin B for systemic infection
- mimic TB (granuloma formation)
65
Tinea versicolor
- Malassezia furfur
- hypo/hyperpigmented patches
- hot/humid weather
- spaghetti and meatball appearance
- topical miconazole, selenium sulfide
66
Giardiasis
- Giardia lamblia
- bloating, flatulence, foul-smelling, fatty diarrhea
- cysts in water
- trophozoites or cysts in stool
- metronidazole
67
Amebiasis
- Entamoeba histolytica
- bloody diarrhea
- liver abscess
- RUQ pain (rupture of submucosal abscess of colon)
- cysts in water
- trophozoites (with RBC's in the cytoplasm)
- cysts in stool
- metronidazole or iodoquinol (for asymptomatic cyst passers)
68
Cryptosporidium
- severe diarrhea in AIDS
- water diarrhea in immunocompetent
- oocysts in water
- acidfast stain
- nitazoxanide in immunocompetent
69
Toxoplasmosis
- Toxoplasma gondii
- brain abscess in HIV
- chorioretinitis, hydrocephalus, intracranial calcifications
- cysts in meat or oocysts in cat feces, placental transmission
- serology or biopsy (tachyzoite)
- sulfadiazine+pyrimethamine
70
Naegleria fowleria
- rapidly fatal meningoencephalitis
- swimming in freshwater lakes (enters via cribiform plates)
- ameobas in spinal fluid
- amphotericin B
71
Trypanosoma brucei
- African sleeping sickness (enlarged lymph nodes, recurring fever, somnolence, coma)
- antigenic variation
- tsetse fly
- suramin for blood-borne disease or melarsoprol for CNS penetration
72
Babesia
- babesiosis
- fever, hemolytic anemia
- Ixodes tick, northeastern U.S.
- blood smear either ring or Maltese cross
- Tx, atovaquone, azithromycin
73
Trypanosoma cruzi
- Chagas disease
- dilated cardiomyopathy, megacolon, megaesophagus
- reduviid bug
- Tx, benznidazole, nifurtimox
74
Leishmania donovani
- visceral leishmaniasis
- spiking fevers, hepatosplenomegaly, pancytopenia
- sandfly
- macrophages containing amastigotes
- Tx, amphotericin B, sodium stibogluconate
75
Trichomonas vaginalis
- vaginitis
- foul smelling, greenish discharge, itching and burning
- trophozoites on wet mount
- metronidazole for patient and partner
76
Enterobius vermicularis (pinworm)
- fecal oral
- intestinal infection causing anal pruritis
- scotch tape test
- bendazoles or pyrantel pamoate
77
Ascaris lumbricoides (giant roundworm)
- fecal oral
- intestinal infection
- bendazoles or pyrantel pamoate
78
Strongyloides stercoralis
- larvae in soil penetrate the skin
- intestinal infection causing vomiting, diarrhea, epigastric pain
- ivermectin or albendazole
79
Ancylostoma duodenale, Necator americanus (hookworm)
- larvae penetrate skin
- intestinal infection causing anemia by sucking blood from intestinal walls
- bendazoles or pyrantel pamoate
80
Onchocerca volvulus
- female blackfly
- hyperpigmented skin and river blindness
- ivermectin
81
Loa loa
- deer, horse, mango fly
- swelling in skin, worm in conjunctiva
- diethylcarbamazine
82
Wuchereria bancrofti
- female mosquito
- blocks lymphatic vessels
- elephantiasis (takes 9 mo to 1yr)
- diethylcarbamazine
83
Toxocara canis
- fecal oral
- visceral larva migrans
- albendazole or mebendazole
84
Taenia solium
- ingestion of larvae encysted in undercooked pork, eggs
- intestinalinfection
- cysticercosis, neurocysticercosis
- praziqunatel, albendazole
85
Diphyllobothrium latum
- ingestion of larvae from raw freshwater fish
- vitamin B12 deficiency (pernicious anemia)
- praziquantel
86
Echinococcus granulosus
- ingestion of eggs from dog feces
- hydatid cysts in liver, anaphyalxis if antigens released
- albendazole
87
Schistosoma
- snails are host, cercariae penetrate skin of humans
- liver and spleen granulomas, fibrosis and inflammation
- chronic infection can lead to squamous cell carcinoma of the bladder (painless hematuria)
- praziquantel
88
Clonorchis sinensis
- undercooked fish
- biliary tract inflammation, pigmented gallstones, associated with cholangiocarcinoma
- praziquantel
89
Live attenuated vaccinations
smallpox, yellow fever, chickenpox, Sabin polio virus, MMR, intranasal influenza
90
Inactivated vaccinations
rabies, injected influenza, salk polio, HAV vaccines
91
Recombinant vaccinations
HBV, HPV (types 6,11,16,18)
92
Naked (nonenveloped viruses)
Papillomavirus, adenovirus, parvovirus, polyomavirus, calicivirus, picornavirus, reovirus, hepevirus
93
Hepadnavirus (HBV)
- acute or chronic hepatitis
- vaccine
- reverse transcriptase
94
Adenovirus
- febrile pharyngitis
- acute hemorrhagic cystitis
- pneumonia
- conjunctivitis (pink eye)
95
Parvovirus (B19)
- aplastic crises in sickle cell disease
- "slapped cheeks" rash (erythema infectiosum)
- RBC destruction in fetus--> hydrops fetalis and death
- pure RBC aplasia
- rheumatoid arthritis
96
Papillomavirus (HPV)
- warts (1,2,6,11)
| - cervical cancer (16,18)
97
Polyomavirus
- JC virus causing progressive mutlifocal encephalopathy
| - BK virus in kidney transplant patients
98
Poxvirus
- small pox
- cowpox
- molluscum contagiosum (flesh colored dome lesions with central umbilicated dimple)
99
Negative-stranded RNA viruses (RNA-dependent RNA polymerase)
Arenavirus, Bunyavirus, Paramyxovirus, Orthomyxovirus, Filovirus, Rhabdovirus
100
Segmented viruses (RNA)
Bunyavirus, orthomyxovirus, arenavirus, reovirus
101
Picornavirus
- Poliovirus, Echovirus, Rhinovirus, Coxsackievirus, HAV
- polyprotein
- viral meningitis (except rhinovirus)
- enterovirus (except rhinovirus)
102
Rhinovirus
- picornavirus
- noneveloped RNA virus
- destroyed by stomach acid
- common cold
103
Yellow fever virus
- flavivrus (arbovirus)
- Aedes mosquitoes
- high fever, black vomitus, jaundice
104
Rotavirus
- infantile gastroenteritis
- segmented dsRNA virus (reovirus)
- villous destruction with atrophy leads to decreased absorption of Na and loss of K
105
Influenza
- orthomyxovirus
- enveloped, negative ssRNA
- hemagglutinin promotes viral entry, neuraminidase promotes progeny virion release
106
Rubella virus
- togavirus
- fever, postauricular lymphadenopathy, arthralgias, fine rash
- TORCHES (blueberry muffin appearance)
107
Paramyxovirus
- parainfluenza (croup)
- mumps
- measles
- RSV (bronchiolitis, pneumonia)
- F (fusion) protein that transforms respiratory epithelial cells into multinucleated cells
108
Measles
- paramyxovirus
- Koplik spots on buccal mucosa
- maculopauplar rash
- sequelae include subacute sclerosing panencephalitis, encephalitis, giant cell pneumonia
- cough, rhinitis, conjunctivitis
109
Mumps
- paramyxovirus
| - parotitis, orchitis, viral meningitis
110
Rabies
- rhabdovirus
- bullet shaped virus
- Negri bodies (cytoplasmic inclusions in purkinje cells)
- fever, malaise--> agitation, photophobia, hydrophobia--> paralysis, coma--> death
111
Prions
- conversion of PrPc--> PrPsc (beta-pleated)
| - spongiform encephalopathy, dementia, ataxia, death
112
Toxoplasma gondii (TORCHS)
neonatal chorioretinitis, hydrocephalus, intracranial calcification
113
Rubella (TORCHS)
PDA or pulmoanry artery hypoplasia, cataracts, deafness, blueberry muffin rash
114
CMV (TORCHS)
hearing loss, seizures, petechial rash, blueberry muffin rash
115
HSV-2 (TORCHS)
encephalitis, herpetic lesions
116
Syphillis (TORCHS)
stillbirth, hydrops fetalis, facial abnormalities such as notched teeth, saddle nose, short maxilla, saber shins and CV VIII deafness
117
Penicillin G/V Mechanism
- Bind penicillin-binding proteins (transpeptidases)
- block transpeptidase cross-linking of peptidoglycan
- activate autolytic enzymes
118
Penicillin G/V use
gram positive (S. pneumoniae, S. pyogenes, Actinomyces), N. meningitis, T. pallidum
119
Ampicillin, amoxicillin
- Bind penicillin-binding proteins (transpeptidases)
- block transpeptidase cross-linking of peptidoglycan
- activate autolytic enzymes
120
Ampicillin, amoxicillin use
- Penicillin coverage
| - H. influenzae, E.coli, L. monocytogenes, P. mirabilis, Salmonella, Shigella
121
Oxacillin, nafcillin, dicloxacillin
- Penicillinase (beta-lactamase) resistant
| - Used for S. aureus except for MRSA
122
Ticarcillin, piperacillin
- Penicillin use and coverage
| - Additional coverage of pseudomonas and gram negative rods
123
Beta lactamase inhibitors
Clavulanic Acid, Sulbactam, Tazobactam
124
Cephalosporins
- beta lactam durgs
- less susceptible to penicillinases
- Listeria, Chlamydia, Mycoplasma, MRSA, Enterococci are not covered
125
Cefazolin, Cephalexin (1st generation)
- Gram positive cocci
- Proteus mirabilis
- E.coli
- Klebsiella pneumoniae
- S. aureus wound infection prophylaxis
126
Cefoxitin, cefaclor (2nd generation)
Gram positive cocci, H. influenzae, Enterbacter aerogenes, Neisseria, Proteus, E.coli, Klebsiella pneumoniae, Serratia marcescens
127
Ceftriaxone, cefotaxime, ceftazidime (3rd generation)
serious gram-negative infections resistant to other beta lactams
128
Cefepime (4th generation)
Pseudomonas and gram positive organisms
129
Ceftaroline (5th generation)
broad gram positive and gram negative coverage including MRSA but NOT pseudomonas
130
Aztreonam
- monobactam
- no allergic cross reactivity with penicillins
- prevents peptidoglycan cross-linking
- gram-negative rods
131
Carbapenems
imipenem, meropenem, ertapenem, doripenem
Note: imipenem is co-administered with cilastatin (an inhibitor of renal dehydropeptidase I to decrease inactivation by the kidney)
132
Carbapenems (use)
gram-positive cocci, gram-negative rods and anaerobes
133
Carbapenem toxicity
GI distress, skin rash, CNS toxicity (seizures)
134
Vancomycin mechanism
inhibits cell wall peptidogylcan formation by binding D-ala D-ala portion of cell wall precursors
135
Vancomycin use
gram positive only (MRSA, entercocci, C. difficile)
136
Vancomycin (toxicity)
nephrotoxicity, ototoxicity, thrombophlebitis, diffuse flushing aka Red Man syndrome
137
Aminoglycosides
gentamicin, neomycin, amikacin, tobramycin, streptomycin
138
Aminoglycosides mechanism
- bactericidal, inhibit formation of initiation complex and cause misreading of mRNA, also block translocation
- ineffective against anaerobes because requires O2 for uptake
139
Aminoglycosides toxicity
nephrotoxicity, neuromuscular blockade, ototoxicity, teratogen
140
Tetracyclines
tetracycline, doxycycline, minocycline
141
Tetracycline mechanism
bacteriostatic, bind to 30s and prevent attachment of amino-acyl tRNA
142
Tetracycline use
Borrelia burgdorferi, mycoplasma pneumonia, rickettsia, chlamydia (intracellular penetration)
143
Tetracycline toxicity
GI distress, discoloration of teeth and inhibition of bone growth in children, photosensitivity, contraindicated in pregnancy
144
Macrolides
azithromycin, clarithromycin, erythromycin
145
Macrolides mech.
inhibit protein synthesis by blocking translocation, binds the 23S rRNA of the 50S ribosomal subunit, bacteriostatic
146
Macrolides use
Atypical pneumonias (mycoplasma, chlamydia, legionella), STD (chlamydia) and gram positive cocci (pt's with penicillin allergies)
147
Macrolides toxicity
GI dysmotility, Arrhythmia caused by prolonged QT, acute cholestatic hepatitis, rash, eosinophilia
148
Chloramphenicol mech.
blocks peptidyltransferase at 50s ribosomal subunit, bacteriostatic
149
Chloramphenicol use
meningitis (H. influenzae, N. meningitis, S. pneumoniae), Rickettsia rickettsii
150
Chloramphenicol toxicity
anemia, aplastic anemia, gray baby syndrome
151
Clindamycin mech.
blocks peptide transfer (translocation) at 50s subunit, bacteriostatic
152
Clindamycin use
anaerobic infections (Bacteroides, Clostridium perfringens), invasive Group A strep
153
Clindamycin toxicity
pseudomembranous colitis (C.dificile), fever, diarrhea
154
Sulfonamides mech
inhibit folate synthesis, inhibit dihydropteroate synthase
155
Sulfonamides use
gram-positive, gram-negative, nocardia, chlamydia
156
Sulfonamides toxicity
hypersensitivity, hemolysis if G6PD deficient, nephrotoxicity, photosensitivity, kernicterus, displace other drugs from albumin
157
Trimethoprim mech.
inhibits bacterial dihydrofolate reductase (dihydrofolic acid--> tetrahydrofolic acid)
158
Trimethoprim use
used in combination with sulfonamides for UTI's, shigella, salmonella, pneumocystis jirovecii, pneumonia tx and prophylaxis and toxoplasmosis prophylaxis
159
Trimethoprim toxicity
megaloblastic anemia, leukopenia, granulocytopenia
160
Fluoroquinolones (-floxacin) mech.
inhibit DNA gyrase (topoisomerase II) and topoisomerase IV, bactericidal
161
Fluoroquinolones (-floxacin) use
gram-negative rods of urinary and GI tracts (pseudomonas), Neisseria, some gram-positive organisms
162
Fluoroquinolones (-floxacin) toxicity
- GI upset, superinfections, skin rashes, headache, dizziness, tendon rupture
- contraindicated in pregnant women, nursing women, and children<18 yr
163
Metronidazole mech.
- forms free radical toxic metabolites in the bacterial cell that damage DNA
- bactericidal, antiprotozoal
164
Metronidazole use
- Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, -Anaerobes (bacteroides, C. difficile)
- triple therapy with PPi and clarithromycin
165
Metronidazole toxicity
disulfiram-like reaction, headache, metallic taste
166
Isoniazid mech.
decrease synthesis of mycolic acids, bacterial catalase-peroxidase needed to convert isoniazid to active metabolite
167
Isoniazid Use
prophylaxis for M. tuberculosis
168
Isoniazid toxicity
neurotoxicity, hepatotoxicity
169
Rifamycins (rifampin, rifabutin) mech.
inhibits DNA-dependent RNA polymerase
170
Rifamycins (rifampin, rifabutin) use
- M. tuberculosis
- used for meningococcal prophyalxis
- prophylaxis for contacts with HiB
171
Rifamycins (rifampin, rifabutin) toxicity
minor hepatotoxicity, orange body fluids, enzyme (P-450) inducer
172
TB treatment drugs
Rifampin, isoniazid, pyrazinamide, ethambutol
173
Amphotericin B mech.
binds ergosterol, forms membrane pores that allow leakage of electrolytes
174
Amphotericin B use
- serious, systemic mycoses
- cryptococcus, blastomyces, coccidioides, histoplasma, candida, mucor
- concurrently supplement K and Mg
175
Amphotericin B toxicity
fever, chills, hypotension, nephrotoxicity, arrhythmias, anemia, IV phlebitis
176
Nystatin
topical, mouthwash form of amphotericin B
177
Azoles mech.
inhibit ergosterol synthesis by inhibiting the Cyp-450 enzyme lanosterol--> ergosterol
178
Azoles use
- local and less serious systemic mycoses
- chronic cryptococcal meningitis in AIDS patients
- candidal infections
- itraconazole for blastomyces, coccidioides, histoplasma
- clotrimazole and miconazole for topical fungal infections
179
Azoles toxicity
- testosterone synthesis inhibition (gynecomastia)
| - liver dysfunction
180
Flucytosine mech
inhibits DNA and RNA biosynthesis by conversion to 5-fluorouracil by cytosine deaminase
181
Flucytosine use
systemic fungal infections (especially meningitis caused by Cryptococcus) in combination with amphotericin B
182
Flucytosine toxicity
bone marrow suppression
183
Echinocandins (caspofungin, micafungin, anidulafungin)
Mechanism: inhibits cell wall synthesis by inhibiting synthesis of beta-glucan
Use: invasive aspergillosi, candida
Toxicity: GI upset, flushing (histamine release)
184
Terbinafine
Mechanism: inhibits the fungal enzyme squalene epoxidase which inhibits lanesterol synthesis
Use: dermatophytoses (especially onychomycosis)
Toxicity: GI upset, headaches, hepatotoxicty, taste disturbance
185
Griseofulvin
Mechanism: interferes with microtubule function; disrupts mitosis; deposits in keratin-containing tissues
Use: oral treatment of superficial infections; inhibits growth of dermatophytes (tinea, ringworm)
Toxicity: teratogenic, carcinogenic, confusion, headaches, increased P-450, warfarin metabolism
186
Antiprotozoan therapy
pyrimethamine (toxoplasmosis), suramin and melarsoprol (T. brucei), nifurtimox (T.cruzi), sodium stibogluconate (leishmaniasis)
187
Chloroquine
Mechanism: blocks detoxification of heme into hemozoin; heme accumulates and is toxic to plasmodia
Use: treatment of plasmodia except for P. falciparum
Toxicity: retinopathy, retinitis
188
Zanamivir, oseltamivir
inhibit influenza neuraminidase
189
Ribavirin
Mechanism: inhibits synthesis of guanine nucleotides by competitively inhibiting inosine monophosphate dehydrogenase
Use: RSV, chronic hepatitis C
Toxicity: hemolytic anemia, teratogen
190
Acyclovir, famciclovir, valacyclovir mechanism
monophosphorylated by HSV/VZV thymidine kinase and not phosphorylated in uninfected cells to form guanosine analog thus inhibiting viral DNA polymerase by chain termination
Note: ganciclovir has similar mechanism for CMV
191
Foscarnet mechanism
viral DNA polymerase inhibitor that binds to the pyrophosphate-binding site of the enzyme
Note: used when -vir drugs fail
192
Cidofovir
Mechanism: preferentially inhibits DNA polymerase, does not require phosphorylation from virus kinase
Use: CMV retinitis, acyclovir-resistant HSV
Toxicity: nephrotoxicity
