Identificação fenotípica e molecular de bactérias patogênicas associadas à criação de peixes amazônicos

Abstract

The intensification of fish breeding in artificial conditions has led to mortalities caused by opportunistic pathogenic bacteria, leading to huge economic losses. These mortalities can be observed in cultures of regional species such as: pirarucu, tambaqui and matrinxã. The main objectives of this dissertation was to conduct molecular and phenotypic analyzes to identify pathogenic bacteria in Arapaima gigas (pirarucu), Colossoma macropomum (tambaqui) and Brycon amazonicus (matrinxã), and to establish evolutionary relationships between bacteria species. We analyzed 72 bacterial isolates from the culture collection of pathogenic bacteria in fish (Universidade Federal do Amazonas- UFAM), from pirarucu, tambaqui and matrinxã from fish farms. The phenotypic identifications were made using 19 biochemical tests (Gram staining, KOH test, oxidase, catalase, oxidation, fermentation, motility, H2S, indole, gas, glucose, urease, lactose, citrate, arabinose, dulcitol, inositol, raffinose, trehalose). The molecular identifications were performed using partial sequencing of 16S rRNA. Phenotypic and molecular approaches identified 35 bacteria species grouped in 17 genera and nine families: Bacillaceae, Enterobacteriaceae, Enterococcaceae, Flavobacteriaceae, Microbacteriaceae, Moroxellaceae, Paenibacillaceae, Staphylococcaceae and Streptococcaceae. The largest groups were formed by the families (Enterobacteriaceae and Bacillaceae) which were clearly polyphyletic since genera and species within these families were grouped with different genus and species. It can be concluded that the approaches used allow the identification, classification and phylogenetic reconstruction of bacterial isolates studied.