Abstract:
The ornamental fish industry is a globally fast blooming industry. Aeromonas spp. is
known to cause infections in ornamental fish leading to huge economic losses. The
pathogen can contaminate the water and helps for disease transmission. The present study
aims to determine the prevalence of Aeromonas spp. in aquarium water collected from
Uva province and to determine the resistance level of Aeromonas spp. to various
antibiotics. A total of 54 water samples were collected from 14 aquariums in the Uva
province. Bacteria were isolated using Tryptic Soy Agar and isolates were identified
as Aeromonas spp. by Gram negative, oxidase positive, fermentative, and 0/129 resistant.
Antimicrobial susceptibility tests were conducted using Amoxicillin, Tetracycline, and
Chloramphenicol. The prevalence of Aeromonas was reported as 43%.
Among Aeromonas spp. positive samples, 52% were reported from water samples with
sick fish while 48% were reported in water samples without sick fish. The presence
of Aeromonas spp. in water with the absence of sick fish confirms that they were
opportunistic and that they can survive within the water leading to infections under
unfavourable conditions for hosts. According to fisher’s exact test, there is no significant
relationship between water changing frequency and existence of Aeromonas sp. in water
(p>0.05). Antimicrobial susceptibility test results showed that there is a significant
difference between the sensitivity of the isolates to the different antibiotics (p<0.05). The
highest resistance to Amoxicillin and highest susceptibility to Chloramphenicol (74%)
and Tetracycline (65%) were reported. Since, Amoxicillin is one of the most common
antibiotics used in aquariums, heavy use or abuse of amoxicillin might predispose current
findings. In conclusion, 43% is the prevalence of Aeromonas spp. from aquarium water in
the Uva province and Chloramphenicol & Tetracycline can be recommended as the best
antibiotic to treat the infections of Aeromonas spp.
Keywords: Aeromonas spp., Aquarium water, Antibiotics, Ornamental fish
