ceftiofur and Gram-Negative-Bacterial-Infections

The objective of this study was to evaluate the efficacy of intramammary treatment with ceftiofur hydrochloride of nonsevere, clinical coliform mastitis. One hundred four cases on 5 farms met the enrollment criteria for the study. Escherichia coli was the most common coliform species identified in milk samples from cows with mild to moderate clinical mastitis, followed by Klebsiella spp. and Enterobacter spp. At enrollment, a milk sample from the affected quarter was taken and used for on-farm culture or submitted to the laboratory. For cows in the treatment group, treatment was initiated with ceftiofur hydrochloride via intramammary infusion at 24-h intervals for 5 d according to label standards. Cows in the control group did not receive treatment. Culture results were available on the day after enrollment and only cows with coliform mastitis continued in the treatment and untreated control groups. Bacteriological cure was defined based on 2 posttreatment milk samples. Molecular typing was used for final definition of bacteriological cure. Treatment of nonsevere clinical gram-negative mastitis with ceftiofur hydrochloride resulted in a significant increase in bacteriological cure compared with nontreated controls in animals infected with E. coli or Klebsiella spp. Treated animals clinically improved significantly more compared with control cows. No significant differences were observed between treated and control animals in milk production or linear score before or after clinical mastitis. Treated animals left the study less frequently compared with control animals.

Topics: Animals; Anti-Bacterial Agents; Cattle; Cephalosporins; Enterobacteriaceae Infections; Escherichia coli Infections; Female; Gram-Negative Bacterial Infections; Klebsiella Infections; Mammary Glands, Animal; Mastitis, Bovine

The in vitro susceptibilities of 50 field isolates of Riemerella anatipestifer from ducks to ceftiofur and 16 other commonly used antimicrobials were determined. The MIC90 values (MIC refers to minimum inhibitory concentrations) for the antimicrobials used in this study are as follows: penicillin was 16 microg/ml; ceftiofur was 32 microg/ml; cephalothin, chloramphenicol, flumequine, and kanamycin were 64 microg/ml; nalidixic acid, nitrofurantoin, and sulfamethoxazole were 128 microg/ml; amikacin, ampicillin, gentamicin, lincomycin, spectinomycin, streptomycin, tetracycline, and trimethoprim were > or = 256 microg/ml. The therapeutic efficacy of ceftiofur against a highly lethal experimental R. anatipestifer infection in ducks was also evaluated. All experimental ducks were infected through the infraorbital sinus with 1 ml of 9 x 10(9) CFU of R. anatipestifer. Ceftiofur (0, 0.25, 0.5, 1, and 2 mg/kg) was injected subcutaneously 5 hours after infection. A single dose of 2 mg/kg resulted in 73% survival as compared with 10% survival in the infected, but untreated controls.

Topics: Animals; Cephalosporins; Drug Resistance, Multiple, Bacterial; Ducks; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Microbial Sensitivity Tests; Poultry Diseases

Our objective was to determine the activity of ceftiofur sodium against Aeromonas hydrophila and A. sobria isolated from a variety of domestic and imported tropical fish. Twelve antimicrobial drugs were tested for effectiveness against these aeromonads using the Kirby-Bauer Disk Diffusion technique and minimum inhibitory concentration determinations. Ceftiofur sodium was highly effective in vitro against aeromonads isolated from ornamental fish. Of the 42 isolates of Aeromonas spp. tested, none were resistant to ceftiofur sodium; however, all isolates were resistant to ampicillin, and 71% were resistant to tetracycline.

Topics: Aeromonas; Aeromonas hydrophila; Animals; Cephalosporins; Fish Diseases; Fishes; Gram-Negative Bacterial Infections; Microbial Sensitivity Tests