| Congresso Brasileiro de Microbiologia 2023 | Resumo: 901-2 | ||||
Resumo:Microbial taxa are highly sensitive bioindicators of environmental changes, which can be important in formulating effective strategies to mitigate environmental impacts. The identification of bioindicators may occur due to taxonomic annotation based on 16S rRNA-encoding gene sequences through comparison with taxonomic databases such as Greengenes, SILVA and RDP. However, different databases can lead to variations in the characterization of microbial communities. Thus, our study evaluated the interference of the database choice in the distribution of quality assessment bioindicators of marine environments. For this purpose, 16S rRNA gene-encoding sequences previously obtained from three different marine coastal environments, namely, Dois Rios Beach (DR), Abraão Beach (AB), and Guanabara Bay (GB), which were considered low, medium, and highly impacted, respectively, were used to assess the distribution of bacterial genera potentially related to pathogens (BGPRDs). These sequences were analyzed using the QIIME 2 program and grouped into amplicon sequence variants (ASVs). Each ASV was compared with the Greengenes, SILVA and RDP databases. The results showed variations in the abundance and number of BGPRDs depending on the database used. For instance, among the total BGPRDs identified in DR samples, 77.5% were detected by the SILVA database, 92.5% by Greengenes and only 37.5% by RDP. Moreover, certain BGPRD genera were exclusively identified by the Greengenes and SILVA databases for all the analyzed samples. On the other hand, no BGPRD genus was exclusively identified by RDP. Furthermore, the diversity analysis of BGPRDs in each environment showed that the choice of taxonomic database (SILVA, Greengenes and RDP) can directly influence the BGPRDs observed in a given environment. For example, in the GB samples, the richness of ASVs related to BGPRDs detected by the Greengenes database was significantly higher than that observed by the SILVA database (p=0.04). However, no significant difference was observed in the richness of BGPRDs between the RDP and SILVA databases in GB samples. Considering the abovementioned factors, our results showed that the BGPRD richness per environment was affected according to the database used, interfering with the analysis of environmental quality based on the identification of bioindicators (microbial taxa) such as BGPRDs. We conclude that standardization of methods for the characterization of microbial communities is necessary for the use of microbiome information for environmental biomonitoring. Palavras-chave: 16S rRNA encoding gene, anthropogenic impacts, bioindicators, marine pathogens, taxonomic databases Agência de fomento:Coordenação de Aperfeiçoamento de Pessoal de Nível Superior | |||||