Bibliographic citations
Arteaga, C., (2024). Caracterización fenotípica de bacterias del género Aeromonas y evaluación de su patogenicidad en paco, Piaractus brachypomus [Universidad Nacional Agraria La Molina]. https://hdl.handle.net/20.500.12996/6558
Arteaga, C., Caracterización fenotípica de bacterias del género Aeromonas y evaluación de su patogenicidad en paco, Piaractus brachypomus []. PE: Universidad Nacional Agraria La Molina; 2024. https://hdl.handle.net/20.500.12996/6558
@mastersthesis{renati/1113258,
title = "Caracterización fenotípica de bacterias del género Aeromonas y evaluación de su patogenicidad en paco, Piaractus brachypomus",
author = "Arteaga Quico, Caren Estefani",
publisher = "Universidad Nacional Agraria La Molina",
year = "2024"
}
In Amazonian fish species, bacteria of the genus Aeromonas have been associated with outbreaks of Motile Aeromonas hemorrhagic Septicemia (MAS). These bacterial agents are distributed in several aquatic organisms, which interact with commercially important fish such as the paco, Piaractus brachypomus. Therefore, the aim of the present investigation was to characterize phenotypically bacteria of the genus Aeromonas isolated from Amazonian fish and to evaluate their pathogenicity in paco, P. brachypomus. For this purpose, presumptive bacteria of the genus Aeromonas were isolated from internal organs of Amazonian fish from consumer aquaculture and ornamentals. Conventional biochemical tests and commercial identification kits were used. In addition, potential virulence factors such as motility, production of proteases, lipases, hemolysins and dnase at different temperatures were evaluated. The susceptibility of bacterial isolates to some antibiotics was also evaluated. Finally, experimental infections were performed to estimate their pathogenicity in P. brachypomus. Twenty bacteria of the species A. hydrophila, A. dhakensis, A. veronii, A. caviae and A. jandaei were isolated, selected and identified. The biochemical profiles of the bacteria isolated using conventional biochemistry, API 20 E and API 20 NE were variable. The use of these kits, however, allowed unequivocal identification of the bacterial genus and demonstrated phenotypic variability in Aeromonas isolated from Peruvian Amazonian fish. Aeromonas bacteria showed reduced susceptibility to the antibiotics evaluated, mainly to oxytetracycline, an antibiotic widely used in aquaculture worldwide. On the other hand, bacteria administered intraperitoneally were pathogenic to P. brachypomus, but showed different degrees of virulence. A. hydrophila isolates caused high mortality (> 90 %) at low doses of 106 colony forming units (CFU/fish). A. dhakensis has pathogenic potential for P. brachypomus since it produces similar degree of mortality as A. hydrophila. Isolates of A. veronii, A. caviae and A. jandaei caused significant mortality only at the 108 CFU/fish dose. In this context, given the importance of native fish culture, the present study highlights the ability of species of the genus Aeromonas, especially A. hydrophila and A. dhakensis, to cause mortality in P. brachypomus. It also highlights the pathogenic potential of other species such as A. caviae, A. veronii and A. jandaei, species that could impact native fish aquaculture in Peru in the future.
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