Bac-T - Quiz 1-2

drraythe's version from 2015-06-08 23:06


Question Answer
4 major classifications of antibacterial drugs are? do? example?bactericidal (kills bacteria, penicillin), bacteriostatic(inhibits growth, tetracycline), narrow spectrum (bacitracin, penicillin G) and broad spectrum (tetracyclines)
4 major mechanisms of action for antibacterial drugsinhibition of cell wall synthesis, damage to cell membrane function, inhibition of nucleic acid synthesis or function, inhibition of protein synthesis
what should dosage be for antibacterials?3-5x MIC at target site
what antibiotics should you avoid with rabbits?penicillins and cephalosporins
what antibiotics should you not give orally?penicillin G is destroyed in stomach, aminoglycosides (such as gentamicin) are not absorbed in GI (you will "G-Ag on them")
examples of drugs of inhibition of cell wall synthesispenicillins, cephalosporins
examples of drugs which damage cell membrane functionpolymyxins
examples of drugs which inhibit nucleic acid synthesis or functionsulfonamides, quinolones, (enrofloxacin type of fluroquinolone)
examples of drugs which inhibit protein synthesistetracyclines, aminoglycosides (+others)
drug resistance mechanisms of bacteria? (4)1) production of enzymes (eg, beta-lactamase from staph) 2) alteration of target site 3) reduction of bacterial cell wall permeability 4) development of alternate metabolic pathway
what are the major groups of antimicrobial drugs? (6)*beta lactam drugs (penicillins and cephlasporins), *tetracyclines (doxycycline), *aminoglycosides (gentamicin), *Macrolides (erythromycin), *sulfonamides and analogues (sulfa-trimethoprim), *fluoroquinolones (enrofloxacin) [fast]
list the beta lactamspenicilin, penicilin G, ampicilin, amoxacilin, clavamox, ceftazine, ceftiofur
what is the broad spectrum penacilin? the narrow? broad = ampicilin, narrow= penicillin G
what are the potentiated penicillins?ampicillin+sulbactam and amoxicillin+clavulanic acid.
what does potentiation of a penacillin mean?add other substance to stop beta-lactamase
what type of group is cephalosporins in? how are cephalosporins divided, and examples? spectrum? betalactams, divided into generations, only really care about 3rd generation (ceftazidime for dogs, ceftiofur for cattle/horse) - broad spectrum
how would you classify tetracyclines, what do they treat?broad spectrum, g+ and g-
examples of tetracyclines?oxytetracycline, doxycycline
possible problem with tetracyclines?enteric bacteria are often resistant, and they destroy useful enteric flora, so problematic if used for a long time
tetracyclines can be used to treatavian chlamydiosis, feline mycoplasmosis, feline chlamydophila, ehrlichia and rickettsia and neorickettesia in dogs. oxytetracycline for pink eye in cattle
the main aminoglycosides? (5) (1 we really care about, two we sort of do)streptomycin, neomycin, kanamycin, **gentamycin (better than all previous...super effective on pseudomonas, good on gram negs), amikacin
the main macrolides? (4) (1 big one)**erythromycin (mainly g+s, strep, staph, campylobacter, lepto), tylosin, tiamulin, tilmicosin
sulfonamide+trimethoprim basics?inhibit nucleic acid synthesis, generally broad spectrum but not effective against campylobacter or pseudomonas (use for ecoli, salmonella, nocardia) for dogs and large animals esp UTIs and resp. infections
basics of fluroquinolonesbroad spectrum (g pos and g neg), doesnt work against anaerobes. good distribution in tissues (inhibit nucleic acid synth.)
examples of fluroquinolonesenrofloxacin, orbifloxacin
bacitracin facts?g+s, narrow spectrum, topical application
polymyxing-s, including pseudomonas
clindamycintreats anaerobes
florfenicolBRD-bovine respiratory disease, pasturella, mannheimia
rifampintreat mycobacterium, rhodococcus equi
what bacteria dont need susceptibility testingcorneybacterium, erysipelothrix, bacillus
metronidazoletreat anaerobes
what causes strangles in horses?streptococcus equi
enrofloxacininhibit nucleic acid synthesis
example of what produces beta-lactamase?staph aureus
what bacteria are penicillin G most effective against? (4)corynebacterium, MOST streptococcus. also clostridium and erysipelothrix
what does sulbactam do?inactivates Beta-lactamase
what is amoxicillin-clavulanic acid effective against? not effective against? broad spectrum including anaerobes, but NOT pseudomonas and mycoplasma
tetracyclines spectrum, and effective against what? (3)broad spectrum so gram pos and gram neg. effective on brucella, mycoplasma, chlamydia
what drug is reccomended for treatment of pink eye in cattle?oxytetracycline
what two drugs are considered better than gentamycin, what do they treat, their class?amikacin, tobramycin. aminolycosides. treat pseudomonas
what is erythromycin good against?Gram positives mainly. strep, staph, campylobacter, leptospira
what is trimethoprim-sulfadiazine commonly used for?E. coli UTIs and bordetella respiratory infections
what is fluroquinolones spectrum? used for what, not used for what?broad spectrum lots of gram pos and gram neg but NO anaerobes
for a streptococcal infection such as strangles in horses will you use a narrow spectrum drug such as penicillin or go for a broad spectrum drug such as tetracycline?tetracycline kills gut flora....therefore kills horses. use penicillin.
Would you use an older drug such as amoxicillin or more recent enrofloxacin for an anaerobic infection in a dog?enrofloxacin is NOT effective on anarobes. Use amoxicillin.
fluroquinalones are not effective on what?anaerobes
good on pseudomonas?aminoglycosides (esp. gentamycin), polymixin, fluroquinalones
not good on pseudomonas?sulfonamides, clavamox
penicillins treat mostly what grams?positive
aminoglycosides treat what grams?negatives, including pseudomonas
sulfonamides treat what grams?negatives
penicillin G treats what grams?postivites
ceftazidine and ceftiofur treat what grams?negatives (including pseudomonas)

the drug table

Question Answer
penicillin G= activity (bacteria) and diseases?activity= strep, coryne, erysipelothrix, clostridium. diseases= strangles, tetanus, black leg, coryne urinary infection
ampicillin and amoxicillin= activity (bacteria) and diseases?activity= strep,coryne, erysipelothrix, clostridium and a few gram negs. diseases= resp. infections
amoxicillin-calvulanate= activity (bacteria) and diseases?activity= staph, strep, some gram negatives, anaerobes. diseases= pyoderma, UTI, resp. infection, anal sac abscess
cephalexin, cefadroxil= activity (bacteria) and diseases?activity= staph, strep. diseases= pyoderma, UTI
ceftazidime, ceftiofur= activity (bacteria) and diseases?activity= gram negs, including psuedomonas. diseases= wound, resp. infections
tetracyclines= activity (bacteria) and diseases?activity= brucella, moraxella, listeria, mycoplasma, chlamydia, rickettsia, ehrlichia. diseases= brucellosis dogs, pink eye cattle, chlamydiosis cats, birds, rickettsial, ehrlichial
aminoglycosides (gentamicin,amikacin)= activity (bacteria) and diseases?activity= gram negs including pseudomonas. diseases= otitis externa dogs, gram neg endometriosis in horse
macrolides (erythromycin, tylosin)= activity (bacteria) and diseases?activity= rhodococcus equi, campy jejuni. diseases= (ery+rifampin for R. equi pneumonia) diarrhea dogs
sulfonamide-trimethoprim= activity (bacteria) and diseases?activity= gram negs (e coli, salmonella, bordetella) NOT pseudomonas. diseases= UTI and resp tract infections
fluroquinolones (enrofloxacin, orbifloxacin)= activity (bacteria) and diseases?activity= gram negs, most pseudomonas, gram pos, include staph. NOT anaerobes. Diseases= UTI, resp infections, pyoderma, osteomyelitis in sm animals

sterilization and disinfection

Question Answer
4 physical agents of sterilization?moist heat, dry heat, radiation, filtration
moist heat as a sterilization method?boiling = spores survive. autoclaving is very effective
dry heat as a sterilization method?good for glassware
radiation/ UV as a sterilization method?for theatres and innoculation hoods, or ionizing radiation/ gamma rays for catheters and plastic petri dishes (kills spores)
filtration as a sterilization method?serum, injectible solution *(mycoplasma will pass through)
chemical agents of sterilization? (7)soluble alcohols, sterilizing gas, disinfectant gas, glutaraldehyde, halogens, phenolics, detergents
soluble alcohols as a sterilization method?rapidly bactericidal
sterilizing gas as a sterilization method?ethylene oxide
disinfecting gas as a sterilization method?**formaldehyde = SPORICIDAL
glutaraldehyde as a sterilization method?used on inanimate objects
halogens as a sterilization method?**chlorine dioxide (chlorines, iodines) are SPORICIDAL at the right pH
phenolics as a sterilization method?acts in an organic manner
detergents as a sterilization method?chlorhexidine


Question Answer
2 types/classifications of fungifilamentous/branching (moulds) or unicellular (yeasts)
what is the oxygen requirements of fungi?AEROBIC!
pH requirements of fungi? agar grown on?often prefer acidic environment...sabouraud agar (pH 5.5)
fast or slow culture growers?SLOW, 1-4 weeks
temperature preferences of fungi?prefer room temp (25*C)
what drugs are fungi resistant to? why drugs do you need to treat?resistant to antibacterials, need antifungals
what two things are important in diagnosis of fungi?culture and microscopic MORPHOLOGY
example of filamentous fungi (moulds)?aspergillus
what is mycelium?mass of hyphae (filaments)
example of unicellular fungi (yeast?) distinct property of this example?malassezia-- footprint shaped
what does dimorphic fungi mean?have a yeast form (37*C-in body) and a mycelial form (25*C-outside of body)
conidia means?spores
geophilic meansnatural habitat is soil
zoophilic meansnatural habitat is animals
arthroconidia/ arthrospores means? example?spores with hyphal fragmentation (ring worm fungus)
dermatomycoses disease?ring worm fungi (SKIN disease)
yeast/yeast like fungi disease examplescandida, malassezia (dermatitis, otitis)
subcutaneous mycoses ex?sporotrichosis
systemic mycoses examples?aspergillosis, blastomycosis, histoplasmosis, coccidoidomycosis, zygomycosis
what is the morbidity and contagiousness of mycotic infections? any exceptions?low morbidity, low contagiousness, EXCEPT ringworm is very contagious
are mycotic infections acute or chronic?chronic
does the body produce antibodies against fungi? are they effective?rarely protective against fungi
predisposing factors to mycotic infection? (3)lowered host resistance, prolonged antibacterial therapy, heavy exposure to fungal spores
(lab procedure) how do you mount fungi?wet mount, 10% KOH (potassium oxide)
how can you use scotch tape in a lab procedure for fungus? example?scotch tape mounts in lactophenol cotton blue (what the tape is treated with) of fungal hyphae in culture...aspergillus shows typical sporing heads
two lab procedures used on fungi that were also used on bacteria?latex agglutination, ELISA
can you gram stain fungi?just malassezia and yeast (Still not called gram pos or neg tho)

antifungal drugs

Question Answer
amphotericin Btoxic to kidneys, but still highly effective (sometimes only thing that will work) (B-ware of kidneys)
which drug is toxic?amphotericin B (B-aware of the ter-ror)
ketoconazole ("nizoral")BROAD spectrum (filamentous or yeast), most commonly used
which drug is broad spectrum and most commonly used?ketoconazole (ketocommon)
nystatinnarrow spectrum, for candida
what drug would you use to treat candida? is it broad or narrow?nystatin, narrow (want to get grid of yeast, stat! <-every girl ever) (NN)
griseofulvinorally for ringworm infection ( ring worm is grisly)
what would you give for ringworm? how is it administered?griseofulvin, orally

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