本研究利用紫外诱变方法筛选到两株具有磺胺敏感性的菌株H1、H2。DNA鉴定为芽孢杆菌属嗜热脂肪地芽孢杆菌种。将H1、H2作为指示菌，进行牛奶磺胺残留总量检测，发现这两株菌对不同种类的磺胺药物具有不同的灵敏度。当H1、H2处理后芽孢悬液菌落总数比为3:4时，检测试剂盒有较好的灵敏度，分别为磺胺：30 μg/L、磺胺嘧啶：30 μg/L、磺胺甲嘧啶：30 μg/L、磺胺二甲嘧啶：30 μg/L、氨苯磺胺：60 μg/L、磺胺噻唑：45 μg/L、磺胺氯哒嗪：80 μg/L、磺胺甲噁唑：75 μg/L、磺胺胍：75 μg/L。在此比例下对两株菌同时传代，探究菌株传代对检测试剂盒灵敏度的影响，结果表明以第四代菌为指示菌时，该检测试剂盒丧失对氨苯磺胺和磺胺胍的敏感性；第六代丧失对磺胺氯哒嗪、磺胺甲噁唑的敏感性；对于磺胺、磺胺嘧啶、磺胺甲嘧啶、磺胺噻唑的敏感性可稳定到第七代。通过与国内外商业试剂盒对比，本试剂盒灵敏度高于国内试剂盒，检测时间优于国外试剂盒。

In this study, two strains with sulfonamide-sensitive strains H1 and H2 were screened by UV mutagenesis. After DNA identification, the two strains were of the genus Bacillus, a species of Geobacillus stearothermophilus. Using H1 and H2 as the indicator bacteria, the total amount of sulfonamide residues in milk was detected, and the obtained results showed that these two strains exhibited different sensitivities to different kinds of sulfa drugs. When the total colony ratio of spore suspension for H1 and H2 was 3:4, the test kit had good sensitivity: sulfonamide, 30 μg/L; sulfadiazine, 30 μg/L; sulfamethazine, 30 μg/L; sulfamethazine, 30 μg/L; sulfonamide, 60 μg/L; sulfathiazole, 45 μg/L; sulfachloropyridazine, 80 μg/L; sulfamethoxazole, 75 μg/L; sulfazone, 75 μg/L. Under these conditions, the two strains were simultaneously passaged, and the effect of strain passage on the sensitivity of the test kit was investigated. The results showed that the test kit lost sensitivities to sulfonamide and sulfaguanidine when the fourth generation bacteria was used as the indicator. The sensitivity to sulfachloropurazine or sulfamethoxazole also lost when the sixth generation was used. Whereas, the sensitivity to sulfonamides, sulfadiazine, sulfamethazine or sulfathiazole remained constant till the seventh generation. Compared with domestic and overseas commercial kits, this kit had a higher sensitivity than the domestic kits, and showed advantage in detection time over the overeas kits.

山东省高等学校科技计划项目（J15LE13）；青岛农业大学高层次人才启动基金项目（6631113347）