Related Experiment Videos
Effect of aztreonam on the growth of Pasteurella multocida in the lung
Abstract:
Specific-pathogen-free ICR mice were infected aerogenically with Pasteurella multocida and, beginning 1 hour later, were treated with aztreonam (50 mg/kg of body weight). The number of viable bacilli in the lungs, liver, and spleen were determined at intervals for up to 36 hours. Aztreonam was bactericidal for growing bacilli in vitro and, when injected 1 and 5 hours after aerogenic exposure, provided greater than 80% protection after dosage at the level of 12.5 mg/kg. Below this dosage level, viable organisms persisted in the lungs and the spleen and many of the minimally treated mice eventually died of pasteurellosis. The survivors developed active immunity as a result of the continued sublethal infection. Aztreonam protects mice against an aerogenic infection with highly virulent P multocida and may be useful in the prevention and treatment of pasteurellosis in cattle.
Insights
Aztreonam effectively protected mice against Pasteurella multocida infection. This antibiotic may be valuable for preventing and treating pasteurellosis in cattle.
Area of Science:
- Veterinary Medicine
- Microbiology
- Pharmacology
Background:
- Pasteurella multocida is a significant pathogen causing respiratory infections.
- Aerogenic transmission poses a challenge for effective treatment.
- Developing efficient therapeutic strategies is crucial for animal health.
Purpose of the Study:
- To evaluate the efficacy of aztreonam against Pasteurella multocida.
- To determine the protective effects of aztreonam in a mouse model of aerogenic infection.
- To assess the potential of aztreonam for treating pasteurellosis in cattle.
Main Methods:
- Specific-pathogen-free ICR mice were infected with Pasteurella multocida via aerosol.
- Aztreonam treatment was initiated 1 hour post-infection at various dosages.
- Bacterial load in lungs, liver, and spleen was quantified over 36 hours.
Main Results:
- Aztreonam demonstrated bactericidal activity against growing Pasteurella multocida in vitro.
- Doses of 12.5 mg/kg aztreonam provided over 80% protection when administered 1 and 5 hours post-infection.
- Lower doses resulted in persistent bacterial infections and mortality, with survivors developing immunity.
Conclusions:
- Aztreonam confers protection against aerogenic Pasteurella multocida infection in mice.
- The findings suggest aztreonam's potential utility in preventing and treating pasteurellosis in cattle.
- Optimal dosing is critical for achieving therapeutic success and preventing resistance development.