Abx II: Inhibitors of Protein Synthesis www.drugs.com/vet/ Lincosamides Abx II: Macrolides As a class of Abx Broad Spectrum, good tissue dist. Achieve high intracellular levels G+ves (R. equi), Campy. jejuni, respiratory pathogens Erythromycin Saccharopolyspora erythraea Erythromycin Resistance: 50s rrna subunit modification Cross-selection of resistance (Lincosamides and Streptogramin) Efflux pump Adverse Effects i.m. (pain), i.v (phlebitis), i.m.m. inflammation, dysbiosis (adult horses, rabbits, rodents) 1
Abx II: Macrolides Erythromycin (Galllimycin ) can be useful if Penicillin allergy Dogs/Cats (p.o.) C. jejuni drug of choice, SSTI s with G+ve cocci Foals (p.o. ) R. equi in combination with rifampin Foals Lawsonia intracellularis +/- rifampin Cattle - primarily for Staph/ Strep mastitis Tylosin better Mycoplasma activity Cattle (i.m. or feed) foot rot, BRDC, feedlot associated liver abscess Swine (i.m. or feed) Mycoplasma, PRDC, PAR, erysipelas, proliferative enteropathy (Lawsonia intracellularis) Dogs colitis, pyoderma with S. pseudintermedius Cats FRDC in cats (Chlamydophila and Mycoplasma) Horses fatal diarrhea s can occur: no indication for use Abx II: Macrolides Tilmicosin: S.Q or feed only : i.m/i.v. cardiotoxicity (fatal) BRDC (Micotil ) S.Q. Lamb pneumonia (Mannheimia) - S.Q. PRDC (Pulmotil ) in feed fatal if i.m. Horse do not use Tulathromycin - (Draxxin ): safer, broader spectrum, injectable BRDC (S.Q.) + Mycoplasmas, pink eye, foot rot, PRDC (i.m.) Newer Macrolides: Clarithromycin (Biaxin ) and Azithromycin Licensed for dogs, cats, foals (p.o. in all) Foals Rhodococcus equi infections in combination with rifampin 2
Abx II: Inhibitors of Protein Synthesis Lincosamides & Pleuromutilins Abx II: Lincosamides & Pleuromutilin Bacteriostatic/cidal dose dependent, 50S ribosome is target moderate-spectrum of activity Lincosamides cross-resistance with Macrolides Parenteral - dogs/cats (parenteral or p.o) Lincomycin + spectinomycin for BRDC, mycoplasma in poultry Lincomycin: footrot (sheep) and swine dysentery + Mycoplasma (swine) Clindamycin: broad-spectrum (p.o) Gram +ves, G+ve and G-ve anaerobes +/- Mycoplasma Dogs/cats SSTI s (Staph and anaerobes) ie. wound infections Pirlimycin: mastitis (G+ves including Staph.) 3
Abx II: Lincosamides & Pleuromutilin Pleuromutilin Tiamulin: primarily G+ves, anaerobes and Mycoplasma s Used primarily in swine (swine dysentery, pneumonia with Mycoplasma/APP ) + Leptospirosis Growth promoter (swine) Streptogramins: Virginiamycin: Gram +ve including anaerobes Growth promoter (swine, cattle) Abx II: Inhibitors of Protein Synthesis Lincosamides & Pleuromutilins 4
Abx II: Chloramphenicol + Florfenicol Chloramphenicol Broad spectrum including Enterobacteria Chlamydophila spp, Rickettsiales, and anaerobes prohibited in food animals (human aplastic anemia) Handling by vet/owner can lead to aplastic anemia Dogs/Cats (p.o., i.m., i.v.); horses (p.o.) other safer Abx Florfenicol: spectrum as per Chloramphenicol, bacteriostatic no aplastic anemia and more effective against most bugs Lipid soluble, blocks protein synthesis (50s ribosomal subunit) Food animals including fish, also dogs and cats (p.o., i.m.) Cattle (Nuflor ) BRDC (parenteral) footrot cattle Swine : PRDC (p.o. in water) - dogs/cats (p.o., i.m.) 5