Rapid Aeromonas hydrophila identification by TaqMan PCR assay: comparison with a phenotypic method

Aeromonas hydrophila is recognized as a human pathogen following wound exposure or ingestion of contaminated water and food. For rapid identification of this bacterium, a TaqMan-based real-time PCR assay has been developed.

Primers and probes that target specific sequences of the 16S rRNA gene and cytolytic enterotoxin gene (aerA) were combined in a duplex assay. Presence and size of PCR products were confirmed with microchannel fluidics electrophoresis analysis. After validation, using type strain CIP7614T DNA, the PCR assay was tested on 12 positive and negative controls. Twenty-one Aeromonas strains were isolated from environmental samples and were identified with biochemical tests as Aer. sobria, Aer. caviae and Aer. hydrophila. Only Aer. hydrophila strains tested positive by PCR assay.

The PCR developed here was successfully applied for the identification of Aer. hydrophila from reference, clinical and environmental samples and showed a high discrimination between Aer. hydrophila and other Aeromonas species.

This molecular method is convenient, rapid (2.5 h vs 24 h), specific to identify Aer. hydrophila and usable for diagnosis in medical and veterinary laboratories.