Is Aeromonas hydrophila the dominant motile Aeromonas species that causes disease outbreaks in aquaculture production in the Zhejiang Province of China?
Me. Nielsen et al., Is Aeromonas hydrophila the dominant motile Aeromonas species that causes disease outbreaks in aquaculture production in the Zhejiang Province of China?, DIS AQU ORG, 46(1), 2001, pp. 23-29
The significance of Aeromonas hydrophila in association with disease outbre
aks in aquaculture production in the Zhejiang province of China was investi
gated. Bacteriological examination of moribund fish and crabs resulted in 9
5 bacterial isolates: 88 bacterial isolates from fish and 7 isolates from c
rabs. PCR and traditional biochemical methods were used for identification
of A. hydrophila. Out of 69 motile aeromonads, 35 isolates were identified
as A. hydrophila by biochemical tests. However, 6 of those were not identif
ied as A. hydrophila by a species specific PCR method. Serotyping revealed
2 dominant serotypes (09 and 097) among A. hydrophila isolates. The data pr
esented show that approximately 42% of the motile aeromonads isolated from
disease outbreaks among various fish species were A. hydrophila. It is note
worthy that A. hydrophila accounted for more than 50% of the isolated aerom
onands isolated from crucian carp Carassius carassius and Wuchang bream Meg
alobrama amblycephala with haemorrhagic septicaemia. Although this species
was the most frequently isolated organism from internal organs of diseased
fish and crabs in the present study, other motile Aeromonas spp. were also
found. The PCR assay was useful in preventing misidentification of A. hydro
phila, which may occur when only phenotypic tests are employed.