Discovery of a bacteriophage sequence in a mite genome assembly reveals bacterial contamination and opens new possibilities for exploring arthropod symbionts

While studying the integration site of a bacteriophage associated with the bacterium <i>Acinetobacter baumannii</i>, we found a genome assembly of the mite <i>Oppiella nova</i> that contained a homologous sequence of this locus. We initially thought of horizontal gene transfer, but it actually uncovered the contamination of 41 genome fragments with a total of 2.28 Mb. This has allowed us to assemble a new genome of the species <i>Acinetobacter guillouiae</i>, which could be a symbiont of the mite, based on the identification of genes potentially related to the diet of this arthropod. This contamination has been unknowingly spread, at least in another article in which authors studied a gene associated with antibiotic resistance. These results recommend the re-assembly of the <i>O. nova</i> genome and show how current sequencing databases have information to study microbial symbionts without the need for new experimentation.