적리를 동반하는 돼지 분변에서 용혈성 균주를 분리 동정한 후, 장 독소 생성 유 무 및 항생제 감수성 시험을 수행하였다. 분리된 용혈성 균주 B. cereus BY06의 gyrB 유전자 염기서열을 분석한 결과, B. cereus와 99% 유사성을 나타내었다. PCR법에 의한 장 독소 유전자 검출 시험에서 B. cereus BY06는 장 독소 분비 양성으로 판정됨에 따라 설사형 식중독 균임이 확인되었다. B. cereus BY06를 이용한 항균제의 감수성 시험 결과, penicillin G에는 내성을 나타낸 반면 cephalothin, vancomycin, clindamycin, fusidic acid, gentamicin, ciprofloxacin, tetracycline 및 rifampin에 대하여 감수성을 나타냈다. 본 연구를 통해 돼지 분변에서 분리된 B. cereus 균주는 설사를 유발하는 장 독소를 분비하며, penicillin G에 대한 내성을 확인하였다.
The enterotoxin production and antimicrobial susceptibility on hemolytic strains from stools of diarrheal pigs was investigated in this study. Through morphological observation, gyrB nucleotide sequence, and API kit analysis, the selected potential pathogenic strain BY06 was identified as Bacillus cereus. Because the characteristic of enterotoxin symptoms were widely caused by Bacillus cereus strains, a PCR test was carried out in order to check the enterotoxin genes (hblA) in this strain. According to the results, this strain was an enterotoxin positive strain containing the hblA gene. The minimum inhibitory concentrations of 10 different antimicrobial agents were screened by the agar dilution test, indicating that this strain was resistant to penicillin G and intermediate to erythromycin; however, it susceptible to cephalothin, vancomycin, clindamycin, fusidic acid, gentamicin, ciprofloxacin, tetracycline and rifampin. These results suggest that the B. cereus BY06 isolated from pig feces has a potential risk of producing enterotoxin and is resistant to penicillin G, but susceptible to various antimicrobial agents.