AUTHOR=Sweeney Michael T., Quesnell Rebecca , Tiwari Raksha , LeMay Mary , Watts Jeffrey 

TITLE=In vitro activity and rodent efficacy of clinafloxacin for bovine and swine respiratory disease

JOURNAL=Frontiers in Microbiology

VOLUME=4

YEAR=2013

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2013.00154

DOI=10.3389/fmicb.2013.00154

ISSN=1664-302X

ABSTRACT=<p>Clinafloxacin is a broad-spectrum fluoroquinolone that was originally developed and subsequently abandoned in the late 1990s as a human health antibiotic for respiratory diseases. The purpose of this study was to investigate the activity of clinafloxacin as a possible treatment for respiratory disease in cattle and pigs. Minimum inhibitory concentration (MIC) values were determined using Clinical and Laboratory Standards Institute recommended procedures with recent strains from the Zoetis culture collection. Rodent efficacy was determined in CD-1 mice infected systemically or intranasally with bovine <italic>Mannheimia haemolytica</italic> or <italic>Pasteurella multocida</italic>, or swine <italic>Actinobacillus pleuropneumoniae</italic>, and administered clinafloxacin for determination of ED<sub>50</sub> (efficacious dose-50%) values. The MIC<sub>90</sub> values for clinafloxacin against bovine <italic>P. multocida</italic>, <italic>M. haemolytica</italic>, <italic>Histophilus somni</italic>, and <italic>M. bovis</italic> were 0.125, 0.5, 0.125, and 1 μg/ml, respectively, and the MIC<sub>90</sub> values against swine <italic>P. multocida</italic>, <italic>A. pleuropneumoniae</italic>, <italic>S. suis</italic>, and <italic>M. hyopneumoniae</italic> were í0.03, í0.03, 0.125, and í0.008 μg/ml, respectively. Efficacy in mouse models showed average ED<sub>50</sub> values of 0.019 mg/kg/dose in the bovine <italic>M. haemolytica</italic> systemic infection model, 0.55 mg/kg in the bovine <italic>P. multocida</italic> intranasal lung challenge model, 0.08 mg/kg/dose in the bovine <italic>P. multocida</italic> systemic infection model, and 0.7 mg/kg/dose in the swine <italic>A. pleuropneumoniae</italic> systemic infection model. Clinafloxacin shows good <italic>in vitro</italic> activity and efficacy in mouse models and may be a novel treatment alternative for the treatment of respiratory disease in cattle and pigs.</p>