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.

Valnemulin (marketed under the trade name Econor) is a pleuromutilin antibiotic used to treat swine dysentery, ileitis, colitis and pneumonia. It is approved for veterinary use only. Valnemulin is an antibiotic belonging to the pleuromutilin group, which acts by the inhibition of the initiation of protein synthesis at the level of the bacterial ribosome. Valnemulin has activity against a range of bacteria including those responsible for enteric and respiratory disease in pigs. Valnemulin shows high activity against Mycoplasma spp. and spirochaetes such as Brachyspira hyodysenteriae and Brachyspira pilosicoli. Valnemulin has little activity against Enterobacteriaceae, such as Salmonella spp. and Escherichia coli. There appears to be no resistance development to valnemulin to date by M. hyopneumoniae and L. intracellularis. There have been some increases of MICs of valnemulin against B. hyodysenteriae and to a lesser degree B. pilosicoli, some of which appear to have developed resistance. Valnemulin binds to the ribosome and inhibits bacterial protein synthesis. Resistance development primarily occurs because of changes at the binding site associated with mutations of the ribosomal DNA genes. Econor 10% and 50% is indicated for: The treatment and prevention of swine dysentery. The treatment of clinical signs of porcine proliferative enteropathy (ileitis). The prevention of clinical signs of porcine colonic spirochaetosis (colitis) when the disease has been diagnosed in the herd. Treatment and prevention of swine enzootic pneumonia. At the recommended dosage of 10 - 12 mg/kg bodyweight lung lesions and weight loss are reduced, but infection with Mycoplasma hyopneumoniae is not eliminated. Econor 0.5% and 1% is indicated: For the treatment and prevention of swine dysentery. The treatment of clinical signs of porcine proliferative enteropathy (ileitis). The prevention of clinical signs of porcine colonic spirochaetosis (colitis) when the disease has been diagnosed in the herd.

Pirlimycin is an antibiotic which was approved in the US and Europe for the treatment of subclinical mastitis in lactating dairy cattle associated with common mastitis pathogens, mostly Gram-positive bacterias. The drug exerts its action by binding to the 50S ribosomal subunit, therefore hindering the aminoacyl-tRNA binding and inhibiting the peptidyltransferase reaction, which interferes with protein synthesis within the bacteria.

Rokitamycin is a macrolide antibiotic against Gram-positive bacteria. Synthesized from strains of Streptomyces kitasatoensis. Rokitamycin is an inhibitor of protein synthesis by specifically binding to the 50 S subunit of the ribosome. Specificity towards prokaryotes relies upon the absence of 50S ribosomes in eukaryotes.

Thiamphenicol is a broad-spectrum antibiotic, which is active against gram-positive and gram-negative organisms. The drug is marketed in Asia and Latin America for the treatment of various infections, including sexually transmitted diseases. As many phenicols, thiamphenicol inhibits the protein synthesis in bacterias by binding to 23S ribosomal subunit. In Europe and USA the drug is used in a veterinary practice.

Micronomicin is a new aminoglycosidic antibiotic discovered and developed by Kyowa Hakko Kogyo Co., Ltd. It is produced by Micromonospora sagamiensis var. nonreducans. Investigation of micronomicin performed in 134 research facilities in Japan led to the following results. 1) Micronomicin showed a broad antibacterial spectrum against Gram positive and Gram negative bacteria. 2) In susceptibility tests of clinical isolates, micronomicin was almost similarly active to GM. 3) Bactericidal activity of micronomicin against Pseudomonas aeruginosa and E. coli was higher than those of TOB and DKB. 4) Micronomicin showed a synergistic antibacterial activity against Pseudomonas aeruginosa and E. coli with CBPC and SBPC. 5) The therapeutic activity of micronomicin in mice infected with Pseudomonas aeruginosa and Serratia sp. was in high correlation with in vitro antibacterial activity similarly to that of GM. Micronomicin (sold under the brand names Sagamicin and Luxomicina among others) is an aminoglycoside antibiotic, and like others in its class, binds to the ribosomes of non-resistant cells causing mistranscription of mRNA which fatally inhibits production of essential proteins. Micronomicin sulfate can inhibit bacterial protein synthesis, while destroy the bacterial cell wall. Micronomicin has an antibacterial activity against gram-negative and gram-positive bacteria such as Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Shara, Escherichia coli, etc. Streptococcus pneumoniae and Pneumococcus are sensitive to it, but its activity on anaerobic bacteria and some hemolytic streptococcus is weak.

Arbekacin is a broad-spectrum aminoglycoside used to treat methicillin-resistant Staphylococcus aureus (MRSA). Arbekacin has antibacterial activities against high-level gentamicin-resistant Enterococci, multidrug-resistant Pseudomonas aeruginosa, and Acinetobacter baumannii et al. In a cell-free system, habekacin (arbekacin) interfered with polypeptide synthesis, caused codon misreading, and inhibited translocation of N-acetylphenylalanyl-tRNA from the acceptor site to the donor site on ribosomes. Arbekacin bound to both 50S and 30S ribosomal subunits. Arbekacin has been approved as an injectable formulation in Japan since 1990, under the trade name Habekacin, for the treatment of patients with pneumonia and sepsis caused by MRSA. Meiji Seika Pharma is developing an inhaled aerosol formulation of arbekacin for the treatment of hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia. Nobelpharma is developing an intravenous formulation of arbekacin sulfate, known as nonsense readthrough compound or NPC 14, for the treatment of Duchenne muscular dystrophy.

Acetylspiramycin for spiramycin acetylated derivatives, belonging to 16 membered ring macrolide. It is suitable for sensitive Staphylococcus, Streptococcus and Streptococcus pneumoniae induced by mild to moderate infections, such as pharyngitis, tonsillitis, sinusitis, otitis media, periodontitis, acute bronchitis, chronic bronchitis, pneumonia, non-gonococcal urethritis, skin and soft tissue infection, can be used for the selection of drugs for cryptosporidiosis, or as a treatment for pregnancy women of toxoplasmosis. The mechanism for Acetylspiramycin combined with sensitive microbial 50S ribosomal subunit, RNA dependent inhibition of protein synthesis and bacteriostasis.

Josamycin is a macrolide antibiotic produced by Streptomyces narbonensis var. josamyceticus. Macrolides are inhibitors of protein synthesis. They impair the elongation cycle of the peptidyl chain by specifically binding to the 50S subunit of the ribosome. Josamycin has antimicrobial activity against a wide spectrum of pathogens. It is similar to erythromycin, but does not induce macrolide resistance in staphylococci and appears to have a lower incidence of gastrointestinal side effects. Josamycin is under investigation in US.