tulathromycin and Respiratory-Tract-Infections

The aim of this study is to evaluate the safety and efficacy of gamithromycin (GAM) for the treatment of naturally occurring bacterial swine respiratory disease (SRD) administered IM. A total of 240 pigs (nine-weeks old) were selected from two sites in Heilongjiang Province of China. The pigs showed severe signs of respiratory disease. Among them, 120 pigs were randomly divided into 4 groups of low dose (3 mg/kg), middle dose (6 mg/kg), high dose (12 mg/kg) GAM IM injection and 2.5 mg/kg tulathromycin (TUL) IM injection (positive control group) for phase II clinical trial to screen effective therapeutic dose. The other 120 pigs were randomly divided into 2 groups of 6 mg/kg GAM IM injection and 2.5 mg/kg TUL IM injection (positive control group) for phase III clinical trial to further confirm the efficacy. Animals were clinically observed daily for 14 days after treatment initiation. The predominant pathogens present in pretreatment respiratory tract samples were Streptococcus suis (S. suis) and Actinobacillus pleuropneumoniae (A. pleuropneumoniae). Haemophilus parasuis (H. parasuis) and Pasteurella multocida (P. multocida) were also found in the respiratory tract. All isolates were subjected to in vitro sensitivity testing and the measured minimal inhibitory concentrations (MIC) of GAM were from 0.0625 μg/mL to 8 μg/mL. In all treatment groups, rectal temperature dropped and clinical index (mental status and respiratory symptom) significantly improved after treatment (P ≤ .05). As a result, 82.76% animals treated with the 6 mg/kg GAM injection were cured. This was significantly higher than that of 3 mg/kg GAM injection (P ≤ .05) and similar to that of 12 mg/kg GAM injection and 2.5 mg/kg TUL injection (P > .05) in phase II clinical trial. In phase III clinical trial, 80.70% of animals treated with the 6 mg/kg GAM injection were cured and the cure rate was similar to that of 2.5 mg/kg TUL injection (P > .05). In conclusion, we recommended a single dose (6 mg/kg) of GAM IM injection for the treatment of bacterial SRD.

Topics: Animals; Anti-Bacterial Agents; Bacterial Infections; China; Disaccharides; Dose-Response Relationship, Drug; Heterocyclic Compounds; Macrolides; Respiratory Tract Infections; Swine; Swine Diseases

In vitro susceptibility tests were conducted on bovine and porcine respiratory pathogens isolated from European countries during 2004-2006 for susceptibility to tulathromycin using the recommended methodologies for broth microdilution. The results were compared with data from a similar survey conducted prior to launch in 1998-2001 to monitor for any shift in susceptibility. The importance of maintaining the pH of the culture media within the range 7.2-7.4 was re-affirmed as a key factor in obtaining consistent minimum inhibitory concentration data. The use of recently established interpretative breakpoints would indicate that to date there has been no apparent decrease in susceptibility to tulathromycin since it became widely used across Europe.

Topics: Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Disaccharides; Disease Susceptibility; Dose-Response Relationship, Drug; Drug Resistance, Bacterial; Europe; Haemophilus somnus; Heterocyclic Compounds; Hydrogen-Ion Concentration; Mannheimia haemolytica; Microbial Sensitivity Tests; Mycoplasma bovis; Mycoplasma hyopneumoniae; Pasteurella multocida; Respiratory Tract Infections; Swine; Swine Diseases

Topics: Animals; Anti-Infective Agents; Cattle; Cattle Diseases; Disaccharides; Female; Heterocyclic Compounds; Injections; Legislation, Veterinary; Male; Netherlands; Respiratory Tract Infections; Swine; Swine Diseases; Treatment Outcome; Veterinary Drugs