|Holcomb, H - IOWA STATE UNIVERSITY|
|Tollefson, L - FDA, CVM|
|Dargatz, D - USDA, APHIS, CEAH|
Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: May 8, 1997
Publication Date: N/A
Technical Abstract: Development of resistance to antimicrobics has become a major concern in both human and animal medicine. With the limited availability of new drugs to combat pathogens, prudent and judicious use of antimicrobics is warranted. In 1995, the National Antimicrobial Susceptibility Monitoring System was established primarily to monitor emerging resistance to fluroquinolones. Salmonella was chosen as the sentinel organism. As part of the baseline study for the monitoring system 1,041 Salmonella isolates of veterinary origin were tested against 16 antimicrobics using a Sensititre**TM custom designed microtiter plate. Breakpoint concentrations were used for all antimicrobics. Isolates were obtained from cattle, swine, chickens, turkeys, swine feed, ground product, exotics, dogs, and cats from both clinical and nonclinical isolations. All isolates were susceptible to amikacin, cepotaxime, and ciprofloxacin. Approximately 34% and 28% of the isolates were resistant to tetracycline and sulfamethoxazole, respectively while 13% of the isolates were resistant to both ampicillin and ticarcillin. The following percent resistance was observed for all other antimicrobics - amoxicillin/clavulanic acid (1%), apramycin (1%), ceftiofur (<1%), cephalothin (2%), gentamicin (4%), neomycin (8%), piperacillin (7%), ticarcillin/clavulanic acid (4%), and trimethoprim/sulfa (1%). These data will serve as baseline values for comparison of future studies and provide important information as to the development of resistance.