Sulfapyridine is a competitive inhibitor of the bacterial enzyme dihydropteroate synthetase. It was used to treat of infections in humans in particular, dermatitis herpetiformis (Duhring's disease), a skin problem, but that usage was discontinued by manufacturer. It is also known, that sulfapyridine is one of the two primary metabolite of the anti-inflammatory drug salicylazosulfapyridine.

Sulfaquinoxaline is a veterinary drug, which can be given to animals to treat coccidiosis and Acute Fowl cholera. It has often used in combinations with others drugs. It had its origins in the chemical synthetic program that sprang from the introduction of sulfonamide drugs into human medicine in the 1930s. The program was sustained through the years of World War II despite declining clinical use of that chemical class. Several sulfa drugs were known to be active against the sporozoan parasite (Plasmodium spp.) that causes malaria, but were not satisfactory in clinical practice. A sulfonamide that had a long plasma half-life would ipso facto be considered promising as an antimalarial drug. Sulfaquinoxaline, synthesized during the war, was such a compound. It proved too toxic to be used in human malaria, but was found to be a superior agent against another sporozoan parasite, Eimeria spp., the causative agent of coccidiosis in domestic chickens. In 1948 sulfaquinoxaline was introduced commercially as a poultry coccidiostat. The action mechanism of sulfaquinoxaline is to inhibit the dihydrofolate synthetase to encumber the nucleate synthesis of bacterium and coccidian its active peak to coccidian is at the second schizont stage (the fourth day of coccidial life cycle), so it will not affect the anti-coccidial immunity in chicken.

Pradofloxacin (trade name Veraflox) is a 3rd generation enhanced spectrum veterinary antibiotic of the fluoroquinolone class. It was developed by Bayer HealthCare AG, Animal Health GmbH, and received approval from the European Commission in April 2011 for prescription-only use in veterinary medicine for the treatment of bacterial infections in dogs and cats. The primary mode of action of fluoroquinolones involves interaction with enzymes essential for major DNA functions such as replication, transcription, and recombination. The primary targets for Pradofloxacin are the bacterial DNA gyrase and topoisomerase IV enzymes. Reversible association between Pradofloxacin and DNA gyrase or DNA topoisomerase IV in the target bacteria results in inhibition of these enzymes and rapid death of the bacterial cell. The rapidity and extent of bacterial killing are directly proportional to the drug concentration.

Fusidic acid is a anti-bacterial agent, initially isolated from Fusidium coccineum by Godtfredsen et al (Leo Pharma) in 1960. It is discussed that fusidic acid exerts its anti-microbial effect by inhibiting bacterial elongation factor G, thus suppressing the protein synthesis. Fusidic acid is widely used in Europe under the names Fucidin H(fusidic acid / hydrocortisone acetate), Fucidin (fusidic acid / sodium fusidate) and Fucicort (fusidic acid / betamethasone valerate) for the treatment of primary/secondary skin infections and inflammatory dermatoses.

Tildipirosin is a semisynthetic derivative of the naturally occurring 16-membered macrolide tylosin. Tildipirosin is intended for parenteral treatment of respiratory disease in cattle and swine. Tildipirosin will be administered as a single-dose injection: subcutaneously in cattle and intramuscularly in swine. The anticipated optimal clinical dose is 4 mg/kg bw. Tildipirosin is not used in human medicine. It is marketed under the brand name Zuprevo. As for other macrolides, the antimicrobial activity of tildipirosin is due to its binding to the ribosomal 50S subunit of bacterial cells thereby inhibiting bacterial protein synthesis. The in vitro antimicrobial activity against Gram-negative and Gram-positive pathogens indicates that tildipirosin is effective against a range of bacterial pathogens frequently associated with bovine and swine respiratory disease. Comparison of minimum inhibitory versus bactericidal concentrations shows that generally the antimicrobial action of tildipirosin is bacteriostatic.

Tylvalosin tartrate is a third-generation macrolide antibiotic that has antibacterial activity against Gram-positive, some Gram-negative organisms and mycoplasma. Tylvalosin interferes with protein synthesis by reversibly binding to the 50S ribosome subunit. Tylvalosin binds to the donor site and prevents the translocation necessary for keeping the peptide chain growing. Its effect is essentially confined to rapidly dividing organisms. Tylvalosin tartrate is the active ingredient of Aivlosin -- a modern macrolide that has shown its effectiveness in the control of porcine proliferative enteropathy, EP and swine dysentery.

Gamithromycin, the active pharmaceutical ingredient of ZACTRAN is a novel 7a-azalide that has been developed for treatment and prevention of bovine respiratory disease (BRD). The compound belongs to the 15-membered semi-synthetic macrolide antibiotics of the azalide sub-class with a uniquely positioned alkylated nitrogen at the 7a-position of the lactone ring. Macrolide antibiotics in general have bacteriostatic action by inhibiting bacterial RNA dependent protein biosynthesis, but can also be bactericidal. They reversibly bind to 23S ribosomal RNA in the 50S-subunit of prokaryotic ribosomes and prevent protein elongation during the translocation process. In vitro data show that gamithromycin has both bactericidal and bacteriostatic actions at least at the higher concentrations found in lung tissue. The broad spectrum antimicrobial activity of gamithromycin includes Mannheimia haemolytica, Pasteurella multocida and Histophilus somni, the bacterial pathogens most commonly associated with BRD. Gamithromycin administered subcutaneously is well absorbed and fully bioavailable, and safe for the target animal receiving doses up to five times the recommended dose at 30 mg ⁄ kg body weight. Following s.c. administration, gamithromycin is extensively and rapidly distributed to lung tissue, the site of respiratory infection.

Tilmicosin is a macrolide antibiotic was prepared by chemical modifications of desmycosin, and is used in veterinary. It is recommended for treatment and prevention of pneumonia in cattle, sheep and pigs, associated with Pasteurella haemolytica, P. multocida, Actinobacillus pleuropneumoniae, mycoplasma species and other microorganisms found sensitive to this compound. Tilmicosin belongs to 16-membered ring group of class macrolides. The antimicrobial mechanism seems to be the same for all of the macrolides. They interfere with protein synthesis by reversibly binding to the 50S subunit of the ribosome. They appear to bind at the donor site, thus preventing the translocation necessary to keep the peptide chain growing. The effect is essentially confined to rapidly dividing bacteria and mycoplasmas. Macrolides are regarded as being bacteriostatic but demonstrate bactericidal activity at high concentrations.

Tiamulin is a diterpene antimicrobial with a pleuromutilin chemical structure similar to that of valnemulin. The activity of tiamulin is largely confined to gram-positive micro-organisms and mycoplasma. Tiamulin acts by inhibiting protein synthesis at the ribosomal level. In veterinary medicine, tiamulin is used for treatment and prophylaxis of dysentery, pneumonia and mycoplasmal infections in pigs and poultry. Tiamulin is available as a 2, 10 or 20% premix for pigs and poultry, a 12.5% solution or 45% water soluble powder for addition to drinking water for pigs and poultry, or a 10% injectable formulation for pigs. Tiamulin inhibits protein synthesis by targeting the 50S bacterial ribosomal subunit and binding to peptidyl transferase, the enzyme responsible for forming peptide bonds between amino acids.

Tylosin (trade names Tylocine, Tylan) is a bacteriostat feed additive used in veterinary medicine. It has a broad spectrum of activity against Gram-positive organisms and a limited range of Gram-negative organisms. It is found naturally as a fermentation product of Streptomyces fradiae. It is a macrolide antibiotic. Tylosin is used in veterinary medicine to treat bacterial infections in a wide range of species and has a high margin of safety. Tylosin is certified by the FDA but is only approved for use in livestock such as cattle, chickens, swine, and turkeys. The FDA has prohibited the use of tylosin in dogs and cats, except where it is specifically prescribed by a veterinarian. Tylosin has a bacteriostatic effect on susceptible organisms, caused by inhibition of protein synthesis through binding to the 50S subunit of the bacterial ribosome.