title: Aeromonas hydrophila clinical and environmental ecotypes as revealed by genetic diversity and virulence genes.
abstract: Aeromonas hydrophila strains recovered from clinical samples and ambient sources were phenotypically and genetically identified. In addition, the distribution of putative virulence factors was assayed. To determine the genetic diversity of these strains, random amplification of polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus (ERIC)-PCR markers were used. The discriminatory ability of the techniques, using Simpson's index, was 0.96 for both methods. The most consistent dendrogram was obtained when RAPD and ERIC data were combined. The genetic diversity revealed a high intra-specific genetic diversity (h=0.364+/-0.024 and I=0.538+/-0.030). The strains showed a tendency to cluster according to their origin of isolation (best-cut test 0.80 and bootstrap values >50%). The present study demonstrates and quantifies the high intra-specific diversity within this species and reveals a clear differentiation of strains according to their ecological origin. The distribution of virulence-related genes confirm that A. hydrophila is a genetically heterogeneous species that harbour ecotypes which have different pathogenic potential to human and other animals.
authors.affiliation: Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Apartado Postal CON 174, México, D.F. CP 06400, Mexico.
authors.forename: Ma Guadalupe
authors.initials: MG
authors.lastname: Aguilera-Arreola
authors.forename: César
authors.initials: C
authors.lastname: Hernández-Rodríguez
authors.forename: Gerardo
authors.initials: G
authors.lastname: Zúñiga
authors.forename: María José
authors.initials: MJ
authors.lastname: Figueras
authors.forename: Graciela
authors.initials: G
authors.lastname: Castro-Escarpulli
mesh_terms: D016980:Aeromonas hydrophila / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D015373:Bacterial Typing Techniques / Q000379:methods*; D014644:Genetic Variation; D006801:Humans; D010802:Phylogeny; D019105:Random Amplified Polymorphic DNA Technique; D014774:Virulence / Q000235:genetics*