Learning Module 1: Miscellaneous Antimicrobials
act on gram +
act on gram -
static
cidal
static
cidal
Novobiocin
most effective on aerobic gram + cocci
inhibits ATP binding to DNA gyrase
microbe can't supercoil DNA
PK
administration
intramammary
topical
high bioavailability
poor tissue penetration
bile clearance with EH recycling
resistance
drug target modification
narrow spectrum
indications
food producing animals
mastitis
combo with pen g
aminocyclitols/spectinomycin
targets 30S ribosome site
blocks growing peptide chain
active against
gram - aerobes
Mycoplasma
rapid resistance developing
PK
administration
im
bioavailability
low po
almost 100% im
Vd low with short t1/2
cleared by urine mostly unchanged
indications
companion animals
given po
treat infectious gastroenteritis
thanks to low oral availability
food producing animals
poultry
air sacculitis (Mycoplasma)
respiratory infections
GI infections
chemoprophylaxis for synovitis
cattle
pneumonia
other respiratory infections
sc or im administration
swine
bacterial enteritis
po administration
Glycopeptides/Vancomycin
inhibit peptidoglycan synthesis
concentration dependent bactericidal
PK
low bioavailability po
short half life (2-3hr)
sometimes impregnanted on beads to treat mm infection
last resort drug
Bacitracin
inhibits bactoprenol
membrane protein that shuttles peptidoglycan monomers
stops cell wall formation
PK
low bioavailability po
nephrotoxic if given parenteral or IV
indications
companions
topical
minor eye and skin infections
dogs, cats, horses
food producing animals
swine and poultry
po administration for gram + enteritis
polymixins
positively charged peptide
bind to neg-charged lipid A of LPS in gram.- membranes
concentration-depnent bactericial
bind to free LPS in blood
prevent endotoxemia
active against
gram -
Pseudomonas
po
administered topical or oral
po
administration IV
PK
administered
PO
topical
low bioavailability po
poor tissue penetration
cationic weak bases
cleared in urine
toxic to proximal tubule
indications
companions
cats n dogs
topical teatment
ear
skin
horse
eye
uterine infections
specifically targets
Kleibsiella
Pseudomonas
eye
no approved use in food animals
derived from Bacillus filtrate
Staphylococcus
disorganize the bacterial cel membrane
protein synthesis inhibitor
Oxazolidinones/Linezolid
binds 50S
inhibit protein synthesis
resistance
no cross resistance
increased efflux
point mutation at rRNA drug target site
not yet widely used
Learning Module 1: Miscellaneous Antimicrobials
simplified
act on gram +
static
Novobiocin
most effective on aerobic gram + cocci
Staphylococcus
inhibits ATP binding to DNA gyrase
microbe can't supercoil DNA
Oxazolidinones/Linezolid
binds 50S
inhibit protein synthesis
cidal
Glycopeptides/Vancomycin
inhibit peptidoglycan synthesis
last resort drug
Bacitracin
inhibits bactoprenol
membrane protein that shuttles peptidoglycan monomers
stops cell wall formation
act on gram -
static
aminocyclitols/spectinomycin
targets 30S ribosome site
blocks growing peptide chain
protein synthesis inhibitor
cidal
polymixins
positively charged peptide
bind to neg-charged lipid A of LPS in gram.- membranes
concentration-depnent bactericial
disorganize the bacterial cel membrane
bind to free LPS in blood
prevent endotoxemia