돼지에 殘留된 설파劑의 微生物學的 스크리닝法에 關한 硏究

Studies on the screening of sulfonamide residues in pork by microbioassay

A simplified procedure was described for screening swine urine for the presence of sulfonamide residues. The principle of method is synergism and antagonism of sulfonamide. When sulfonamide is combined with trimetoprim(TMP), antibacterial synergism is obtained. On the other hand, when excessp-aminobenzoic acid(PABA) is present the antibacterial activity of the sulfonamides is overcome. The method involved soaking two discs into swine urine. Each disc is placed on couple of test plates using EEC-four plate inoculated with Bacilus subtilis spore at pH7.2. One plate is incorporated with TMP(TMP-plate), another is PABA(PABA-plate). Diffusion of an antibacterial substance is shown by the formation of zones of inhibition(inhibition zone). Particularly inhibition zone on TMP-plate than PABA-plate considers good evidence to send the specimen for specific sulfonamide residues test. Of a total 220 urine samples tested by this screening method, 63 cases were showed the inhibition zones. Among them, inhibition zones were only shown on TMP-plete in 12 cases and inhibition zones on TMP-plate were much greater than PABA-plate in 8 cases. Accompanied with the microbioassay, thin-layer chromatographic(TLC) tests for screening the sulfonamide residues with Sulfa-On-site(SOS) kit were applied to same samples in which two positive cases were shown. The sulfamethazine residues in 2 TLC positive urine were identified by high performance liquid chromatographic(HPLC) test. One TLC positive sample is one of 12 cases in which inhibition zones on TMP-plate were only shown and another TLC positive sample was also included in much greater inhibition zones on TMP-plate cases. With this result, the possibility of screening the sulfonamide residues in swine urine by this cases. With this result, the possibility of screening the sulfonamide residues in swine urine by this microbioassay is obtained.