Aeromonas hydrophila subsp. ranae subsp. nov., isolated from septicaemic farmed frogs in Thailand.
A group of seven sucrose-negative Aeromonas strains (referred to as group Au) isolated from the internal organs of septicaemic farmed frogs (Rana rugulosa) in Thailand was subjected to a polyphasic taxonomic study including fluorescent amplified fragment length polymorphism (FAFLP) and ERIC-PCR fingerprinting, 16S rDNA sequencing, microplate DNA-DNA hybridizations and extensive phenotypic characterization. Comparison of FAFLP and ERIC-PCR fingerprints indicated that the group Au isolates belonged to the species Aeromonas hydrophila DNA hybridization group (HG) 1 in which they represent a genotypic subgroup closely affiliated to A. hydrophila subsp. hydrophila and subsp. dhakensis. One representative of the Au group exhibited > or = 99.0% 16S rDNA sequence similarity with the type strains of the two A. hydrophila subspecies. DNA-DNA hybridization with type and reference strains of all known Aeromonas taxa revealed that the Au group represented a homogeneous taxon that exhibited the highest relatedness with members of the two A. hydrophila subspecies, ranging from 75 to 93%. Phenotypic characterization on the basis of 152 features further revealed that the Au group isolates differed from A. hydrophila subsp. hydrophila or subsp. dhakensis in a total of 13 biochemical properties. Of these, assimilation of L-glycine and isobutyrate as sole carbon source, acid production from salicin and D-sucrose, and aesculin hydrolysis were of diagnostic value. From the results of this study, it can be concluded that the Aeromonas frog isolates of the Au group represent a new subspecies of A. hydrophila, for which the name Aeromonas hydrophila subsp. ranae subsp. nov. is proposed. Its type strain is Au-1D12(T) (=LMG 19707(T) = CCUG 46211(T)).
Huys
Geert
G
Laboratorium voor Microbiologie, Ghent University, K.L. Ledeganckstr. 35, B-9000 Ghent, Belgium.
Pearson
Marianne
M
Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, UK.
Kämpfer
Peter
P
Institut für Angewandte Mikrobiologie, Justus-Liebig-Universität Giessen, IFZ, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany.
Denys
Rik
R
Laboratorium voor Microbiologie, Ghent University, K.L. Ledeganckstr. 35, B-9000 Ghent, Belgium.
Cnockaert
Margo
M
Laboratorium voor Microbiologie, Ghent University, K.L. Ledeganckstr. 35, B-9000 Ghent, Belgium.
Inglis
Valerie
V
Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, UK.
Swings
Jean
J
Laboratorium voor BCCMTM/LMG Bacteria Collection, Ghent University, K.L. Ledeganckstr. 35, B-9000 Ghent, Belgium.|Laboratorium voor Microbiologie, Ghent University, K.L. Ledeganckstr. 35, B-9000 Ghent, Belgium.
D016980:Aeromonas hydrophila / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D000818:Animals; D017756:Aquaculture; D016470:Bacteremia / Q000382:microbiology*; D015373:Bacterial Typing Techniques; D004275:DNA, Ribosomal / Q000032:analysis; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011898:Ranidae; D017422:Sequence Analysis, DNA; D013785:Thailand
D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S