Genomic analysis of fluoroquinolone-resistant Leclercia adecarboxylata carrying the ISKpn19- orf- qnrS1- Delta IS3-blaLAP-2 module in a synanthropic pigeon, Brazil

Objectives: The aim of this study was to perform a genomic investigation of a multiple fluoroquinolone-resistant Leclercia adecarboxylata strain isolated from a synanthropic pigeon in Sao Paulo, Brazil.Methods: Whole-genome sequencing was performed using an Illumina platform, and in silico deep analy-ses of the resistome were performed. Comparative phylogenomics was conducted using a global collection of publicly available genomes of L. adecarboxylata strains isolated from human and animal hosts.Results: L. adecarboxylata strain P62P1 displayed resistance to human (norfloxacin, ofloxacin, ciprofloxacin, and levofloxacin) and veterinary (enrofloxacin) fluoroquinolones. This multiple quinolone-resistant profile was associated with mutations in the gyrA (S83I) and parC (S80I) genes and the presence of the qnrS gene within an ISKpn19-orf-qnrS1-4IS3-blaLAP-2 module, previously identified in L. adecar-boxylata strains isolated from pig feed and faeces in China. Genes associated with arsenic, silver, copper, and mercury resistance were also predicted. Phylogenomic analysis revealed clustering (378-496 single nucleotide polymorphism differences) with two L. adecarboxylata strains isolated from human and fish sources in China and Portugal, respectively.Conclusions: L. adecarboxylata is a Gram-negative bacterium of the Enterobacterales order and is con-sidered an emergent opportunistic pathogen. Since L. adecarboxylata has adapted to human and animal hosts, genomic surveillance is highly recommended, in order to identify the emergence and spread of re-sistant lineages and high-risk clones. In this regard, this study provides genomic data that can help clarify the role of synanthropic animals in the dissemination of clinically relevant L. adecarboxylata within a One Health context.(c) 2023 The Author(s). Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )