Antibacterial activity of Veraflox (pradofloxacin) oral suspension in vitro and application for the treatment of infections in parrots

Teodora P. Popova, Galabin Mladenov

Abstract: Microbiological studies on materials from 217 parrots with various infections have been performed that showed a significant prevalence of the staphylococcal diseases (39.7% of isolates) in these birds, followed by streptococcal ones (33.7%). The isolated Gram-negative bacteria (17.4%) and fungi (9.2%) were less. The role of S. aureus as an infectious agent in the parrots was leading, and from Gram-negative species – of Klebsiella spp. (in 8.7% of the patients studied), E. coli and Moraxella catarrhalis. The major part (95.4%) of the isolated 197 bacterial strains of 217 parrots showed sensitivity in vitro to Veraflox (a suspension for oral administration containing pradofloxacin), determined by the classical disk agar-gel diffusion method. Resistance was only detected in single staphylococcal and enterococcal strains. All patients treated with it after a positive result of the antibiogram were permanently cured (94.7%), with the exception of 10 birds (5.3%) that came for xamination and treatment in very serious condition. Veraflox oral suspension has been found to be an excellent mean for treating various parrot infections. The dose (15 mg/kg bw) and the frequency of oral administration (24 h) at which an antimicrobial effect occurs without any adverse side effects for the patient have been successfully determined. This is the first report for use of Veraflox in our country and in the world for the treatment of parrots with various infections. Determination of the minimum inhibitory concentrations (MIC) was also performed to accurately assess the antibacterial effect of Veraflox against S. aureus and E. coli. The bacterial strains tested showed high sensitivity to pradofloxacin as well as to the control quinolone enrofloxacin, although the inhibitory effect of enrofloxacin was higher. The susceptibility of tested strains of S. aureus to pradofloxacin was lower than that of E. coli strains. The mean MIC50 values of this quinolone for the Gram-positive bacteria S. aureus (0.25 ± 0.12 μg/ml) were higher than those for the Gram-negative E. coli (0.18 ± 0.06 μg/ml), with significant differences (P < 0.05). The results obtained when determining sensitivity to enrofloxacin were opposite. The development of the tested strains of S. aureus was suppressed by significantly lower concentrations of this quinolone than
those for E. coli. The reported mean MIC50 values for S. aureus were 0.018 ± 0.008 μg/ml, while
those for E. coli – 0.044 ± 0.015 μg/ml.

Keywords: Key words: parrots, infections, Veraflox, pradofloxacin, enrofloxacin, antibacterial activity

Date published: 2020-10-09