Abstract
Antimicrobial resistance to 15 antimicrobials were determined in vitro for 20 Escherichia coli, 11 Klebsiella spp., 11 Staphylococcus spp., 9 Pseudomonas aeruginosa, 5 Arcanobacterium pyogenes, 5 Mannheimia haemolytica and 4 Streptococcus spp., incriminated as the causative agents of pneumonia of camels in Jordan. Susceptibility was determined qualitatively by the agar diffusion method. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values of 5 antimicrobials were determined by the microdilution method. The majority of the isolates were most susceptible to ciprofloxacin and enrofloxacin. Only 40 and 60% of the A. pyogenes isolates, were sensitive to ciprofloxacin and enrofloxacin, respectively. In addition 18% of Klebsiella spp. were resistant to enrofloxacin. Ciprofloxacin minimum inhibitory concentration (MIC50) and minimum bactericidal concentration (MBC) were 0.125 and 0.25 mu g/ml and 0.5 and 1 mu g/ml for P. aeruginosa and S. aureus, respectively. With exception of M. haemolytica and A. pyogenes more than 82% of the isolates Were found to be sensitive to gentamicin with MIC50 and MBC of 0.25 and 0.5 mu g/ml, respectively for S. aureus and 1-and 2 mu g/ml, respectively for E. coli and Klebsiella spp. Flumequine was highly effective against M. haemolytica isolates, whereas', 15% of E. coli isolates were resistant. Streptococcus isolates were 100% sensitive to doxycycline, whereas other isolates displayed resistance with 20% and 67% for M. haemolytica ana P. aeruginosa, respectively. The bacterial isolates showed variable resistance ranged between 9 to 100% to penicillin, ampicillin, amoxicillin, tetracycline, lincomycin, erythromycin, colistin, co-trimoxasole, streptomycin and neomycin. Multiple resistance of 4 and up to 11 different antimicrobials were displayed for E. coli, P. aeruginosa, and Klebsiella spp. and the most common resistance pattern was penicillin, ampicillin, amoxicillin, tetracycline, doxycycline, linocomycin, and erythromycin.
Ciprofloxacin, enrofloxacin and gentamicin appear to have a great potential to control bacterial respiratory infections in camels, with the appropriate dosage that based on pharmacokinetic/ pharmacodynamic studies.