Nógrády Noémi, Gadó I, Pászti Judit, Király Margit
Veterinary Medical Research Institute, Hungarian Academy of Sciences, H-1581 Budapest, P.O. Box 18, Hungary.
Acta Vet Hung. 2003;51(2):137-51. doi: 10.1556/AVet.51.2003.2.2.
By PCR using the ant(3")-Ia primer pair the aadA gene was detected in 34 streptomycin- and spectinomycin-resistant Salmonella enterica serotype Typhimurium strains. Out of them 12 belonged to DT104 and 22 to non-DT104 phage type. Using different primer combinations it was demonstrated that this gene was integron-associated in all cases: in the DT104 strains it was generally contained by a 1 kb integron while in the majority of the non-DT104 strains by a 2.05 kb (less often by a 1.9 or 1 kb) integron. In the case of integrons carrying multiple cassettes the cassette containing the aadA gene was located closer to the 3' end of the integron. The aadA genes of DT104 and non-DT104 strains were different: in the former group the aadA2 gene, while in the latter group (constituted by strains of five different phages types as well as unclassifiable and untypable strains) the aadA1 gene could be identified. The RH50/RH51 primer pair described by Collis and Hall (1992) proved to be suitable for rapid discrimination between the aadA1 and aadA2 genes on the basis that the RH51 primer bound exclusively to the aadA2 gene.
通过使用ant(3")-Ia引物对进行聚合酶链反应（PCR），在34株对链霉素和壮观霉素耐药的肠炎沙门氏菌鼠伤寒血清型菌株中检测到aadA基因。其中12株属于DT104型，22株属于非DT104噬菌体类型。使用不同的引物组合证明，在所有情况下该基因都与整合子相关：在DT104菌株中，它通常包含在一个1 kb的整合子中，而在大多数非DT104菌株中，它包含在一个2.05 kb（较少情况下为1.9或1 kb）的整合子中。对于携带多个盒式结构的整合子，含有aadA基因的盒式结构位于更靠近整合子3'端的位置。DT104和非DT104菌株的aadA基因不同：在前一组中是aadA2基因，而在后一组（由五种不同噬菌体类型的菌株以及无法分类和无法分型的菌株组成）中可以鉴定出aadA1基因。Collis和Hall（1992年）描述的RH50/RH51引物对被证明适用于基于RH51引物仅与aadA2基因结合的特性，快速区分aadA1和aadA2基因。
