用PCR检测嗜水气单胞菌毒素基因

选取气单胞菌毒素基因中保守区的同源寡核苷酸序列为引物，用PCR技术检测临床分离的嗜水气单胞菌的毒素基因。扩增产物中均含有明显的预定条带；用AluI和AvaI酶切进一步鉴定，其酶切片段的数量和大小均与设计相吻合，证实样本中带有毒素基因。细菌在鲜血平板上呈现党大的β－溶血圈，用相应的单克隆抗体检测培养上清中的毒素，亦获阳性结果，进一步证实PCR技术检测气单胞菌毒素准确可靠。

DETECTION OF THE AEROLYSIN GENE OF AEROMONAS HYDROPHILA WITH POLYMERASE CHAIN REACTION

Two 20bp nucleic acid fragments corresponding to aerolysin structural gene(aerA)were used as primers forthe detection of aerA gene in veterinary clinical isolates of Aeromonas hydrophila with polymerase chain reaction(PCR). The 532bp target nucleic acid sequences located in the conservative region at the 3'-terrninus of aerAgene. Agarose electrophoresis showed that the PCR amplified products contained a 532bp nucleic acid band,andAluI and AvaI endonucleases cleavage profiles of the products coincided with that of a cloned aerA gene. Thesehemolytic isolates were proved to be HEC toxin - producing by Dot - ELISA using mono -clonal antibodies against HEC toxin. These results suggest that the aerA gene commonly present in aerononadsand the HEC toxin might be identical with aerolysin and PCR could be a rapid and effective method for detec-tion of aerA gene in aeromonads.