Levofloxacin Antibacterial Activity against Pasteurella Multocida Isolated from Domestic Rabbits

Activity: Talk or presentation types › Oral presentation

Description

Pasteurella multocida (P. multocida ) are zoonotic Gram-negative bacteria, causing numerous diseases in animals and humans. P. multocida is a major respiratory pathogen in rabbits. Levofloxacin (LVFX) is a fluoroquinolone antimicrobial used off-label in veterinary medicine. LVFX antibacterial effects against P. multocida isolated from diseased companion rabbits was evaluated.. Ten P. multocida clinical isolates from pet rabbits with respiratory symptoms (“snuffles”) were obtained. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration values were detected with broth microdilution method according to CLSI guidelines. One isolate with intermediate MIC value detected in serum was selected for bacterial killing rate determination. Time-kill curves were determined as described by Lee et al (2017). Antimicrobial activity was determined in blank serum with addition of LVFX in concentrations of 0.25 MIC - 64 MIC (in vitro) and in serum samples from rabbits treated with LVFX 5 mg/kg IM and SC administration (ex vivo).. P. multocida MIC values were 0.008-0.5 µg/mL, MBC values 0.015 - 0.5 µg/mL. An isolate with MIC 0.015 µg/mL was used for time kill evaluation. LVFX concentrations of ¼ - 1 MIC concentrations did not inhibit bacterial growth after 24 hours of incubation 2 MIC – 64 MIC concentrations of LVFX, resulted in bacterial eradication after 24 hours of incubation. All serums samples from rabbits treated with 5 mg/kg LVFX parenterally from 0.5, 1, 2, 4, 8 and 10 h post administration was able to eradicate sensitive bacterial strain within 24 hours of incubation. AUC0-24/MIC, a PK/PD efficacy index for fluoroquinolones (>72 represents efficacy, according to Madsen et al., 2019) was calculated to be higher than 600 h for both IM and SC routes of administration.. According to rates of bacterial killing in vitro and ex vivo, LVFX is effective for P. multocida infection eradication in rabbits, however further dose studies are required.
Period29 Mar 2023
Event titleRSU International Research Conference 2023: Knowledge for Use in Practice
Event typeConference
OrganiserRīga Stradiņš University
LocationRiga, LatviaShow on map
Degree of RecognitionInternational

Related content