During last decades there has been a continuous growth of aquaculture industries all over the world and taking into
consideration the spurt in freshwater ornamental fish aquaculture and trade in Kerala, the present study was aimed to assess the
prevalence of various motile Aeromonas spp. in fresh water ornamental fishes and associated carriage water. The extracellular
virulence factors and the antibiogram of the isolates were also elucidated. Various species of motile aeromonads such as Aeromonas
caviae, A. hydrophila, A. jandaei, A. schubertii, A. sobria, A. trota and A. veronii were detected. Aeromonas sobria predominated
both fish and water samples. Extracellular enzymes and toxins produced by motile aeromonds are important elements of bacterial
virulence. The production of extracellular virulence factors - proteases, lipase, DNase and haemolysin by the isolates were studied.
All the isolates from both fish and water samples produced gelatinase and nuclease but the ability to produce lipase, caseinase and
haemolysins was found to vary among isolates from different sources. Among the 15 antibiotics to which the isolates were tested, all
the isolates were found to be sensitive to chloramphenicol, ciprofloxacin and gentamicin and resistant to amoxycillin. Local aquarists
maintain the fish in crowded stressful conditions, which could trigger infections by the obligate/ opportunistic pathogenic members
among motile aeromonads
Description:
International Journal of Aquaculture, 2013, Vol.3, No.17, 92-100
Hatha, A A M; Nifty, John(Indian J. Fish, February 29, 2012)
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Abstract:
The objective of the present study was to assess the prevalence of various motile aeromonads in freshwater ornamental fishes
and to elucidate the antibiogram and beta hemolytic activity among the isolates. A total of 120 ornamental fish samples were
screened and analyzed for Aeromonas spp. Motile aeromonads were isolated from 37.5% of the ornamental fish samples.
Various species of motile aeromonads such as Aeromonas caviae, Aeromonas hydrophila, Aeromonas jandaei, Aeromonas
schubertii, Aeromonas sobria, Aeromonas trota and Aeromonas veronii were detected. All the isolates were sensitive to
ceftazidime, chloramphenicol, ciprofloxacin and gentamicin. Multiple antibiotic resistance was observed in 58% of the
isolates.