Authors : K. Porteen, R.K. Agarwal and K.N. Bhilegaonkar
Abstract: A set of primers targeting 16S rRNA gene and aerolysin gene was employed to standardize PCR assay for detection of Aeromonas from milk samples. The primers used were found to be highly specific for Aeromonas spp and did not give positive result with other Gram positive and Gram-negative bacteria. The minimum detection level of PCR was found to be 102 cells -1 and 104cells -1 in case of 16S rRNA and aerolysin gene targeted assay, respectively. Suitability of the enrichment broth (Alkaline peptone water-cephalothin, APW-C) when tested to detect Aeromonas from the spiked samples gave good results on direct usage of the broth for template preparation without any subsequent treatment. The kinetics of the spiking study indicated that a minimum of 24 hrs enrichment was required for the detection of Aeromonas by cultural and PCR method. Among two PCR assays detection limits achieved by PCR targeting16S rRNA gene were better than aerolysin gene PCR assay. The results were comparable to cultural method. Examination of 50 milk samples(Pooled samples) revealed two samples to be positive by cultural method and PCR targeting 16S r RNA.Thus the standardized single �step enrichment PCR protocol holds promise as a reliable and rapid method for the detection of Aeromonas from milk samples.
Porteen, K. , R.K. Agarwal and K.N. Bhilegaonkar , 2006. PCR-Based Detection of Aeromonas from Milk Samples. Journal of Food Technology, 4: 111-115.