Detection and characterization of the hemolysin genes in Aeromonas hydrophila and Aeromonas sobria by multiplex PCR |
| |
| Authors: | Wang Gehua Clark Clifford G Liu Chenyi Pucknell Chad Munro Cindy K Kruk Tamara M A C Caldeira Richard Woodward David L Rodgers Frank G |
| |
| Affiliation: | National Laboratory for Enteric Pathogens. National Laboratory for Bacteriology, National Microbiology Laboratory, Winnipeg, Manitoba, Canada. Gahua_Wang@hc-sc.gc.ca |
| |
| Abstract: | ![]()
A multiplex PCR assay was designed to amplify the Aeromonas hydrophila and A. veronii bv. sobria hemolysin and aerolysin genes. The assay was evaluated by using 121 clinical isolates and 7 reference strains of Aeromonas spp., and these were divided into five genotypes on the basis of the results of the multiplex PCR. The five genotypes were characterized as type 1 for those carrying the ahh1 gene only (36% of isolates), type 2 for those carrying the asa1 gene only (8.5% of isolates), type 3 for those carrying both the ahh1 and the asa1 genes (4% of isolates), type 4 for those carrying the ahh1 gene and the A. hydrophila aerA (aerolysin) gene (37.5% of isolates), and type 5 for those in which no hemolysin genes were detected (14% of isolates). The most common single hemolysin gene carried among all the Aeromonas isolates examined was ahh1, with 99 of 128 (77%) of isolates testing positive for this gene either alone or in combination with other hemolysin genes. Phenotypic expression of toxins was evaluated in a Vero cell culture cytotoxicity assay. These results indicated that there is a statistically significant correlation between the cytotoxin titers and the hemolysin genotype. Isolates belonging to genotype 4 (carrying both the ahh1 gene and the aerolysin and hemolysin aerA genes) expressed higher cytotoxin titers than isolates of the other genotypes (P < 0.001). These isolates were more cytotoxic in cell culture and may have greater clinical significance. |
| |
| Keywords: | |
| 本文献已被 PubMed 等数据库收录！ |
|
