Chesneau, O. | bioRxiv Science

bioRxiv2023

Neisseria leonis sp. nov. isolated from rabbits, reclassification of Uruburuella suis, Uruburuella testudinis, Kingella potus, Bergeriella denitrificans and Morococcus cerebrosus into Neisseria genus and reclassification of Neisseria shayeganii into Eikenella genus

Genome sequence-based identification of two strains (3986T and 51.81) isolated from rabbits in France in 1972 and 1981 and deposited in the Collection of Institut Pasteur (CIP) has led to the description of a novel species in the genus Neisseria. The cells of both strains were non-motile, Gram-stain-negative and diplococcobacilli. Optimal growth on trypticase soy agar was recorded at 37{degrees}C and pH 8.5 in aerobic conditions. Phylogeny based on 16S rRNA gene placed the strains close to Neisseria bacilliformis ATCC BAA-1200T (96.38%) nesting with the members of Neisseriaceae family. Furthermore, the phylogenetic analysis based on bac120 gene set from the Genome Taxonomy Database (GTDB) placed both strains within the monophyletic Neisseria clade, which also included type strains of Morococcus cerebrosus, Bergeriella denitrificans, Kingella potus, Uruburuella suis and Uruburuella testudinis. However, Neisseria shayeganii strain 871T was placed outside Neisseria clade and close to the members of Eikenella genus. Strains 3986T and 51.81 were placed in a branch distinct from all species of the genus Neisseria and exhibited the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values below the species demarcation values. In contrast, ANI value within the two strains was 96.9% confirming that they represent same species. The genomic DNA G+C content of strain 3986T was 56.92%. Based on the phylogenetic and phenotypic data, the strains 3986T and 51.81 represent a novel species of the genus Neisseria, for which the name Neisseria leonis sp. nov. is proposed (type strain 3986T = CIP 109994T = LMG 32907T). Additionally, based on phylogenetic analysis, DUS dialect and average amino acid identity (AAI) values, we also proposed the reclassification of Morococcus cerebrosus, Bergeriella denitrificans, Kingella potus, Uruburuella suis and Uruburuella testudinis into Neisseria genus and Neisseria shayeganii into Eikenella genus. Author NotesThe GenBank accession numbers for the 16S rRNA gene sequence of strains 3986T and 51.81 are respectively OQ121838.1 and OQ428162.1. The draft genome sequences have been deposited in GenBank under the accession numbers JAPQFK000000000 (strain 3986T) and JAPQFL000000000 (strain 51.81). Further explanations mentioned in the article as well as 7 supplementary tables and 7 supplementary figures are available with the online version of this article.

evolutionary biology↗

bioRxiv2023

Hospital and urban wastewaters shape the structure and active resistome of environmental biofilms

BackgroundDemonstration of the transfer, dynamics, and regulation of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) in a complex environmental matrix is yet experimentally challenging, with many essential open questions such as how and where transfer and dissemination of ARGs happens in nature. The extent and conditions of MGEs transfer that carry ARGs is still largely unexplored in natural environments and microbial communities. Biofilms are structures that include high density multi-species bacterial communities embedded in self-produced extracellular polymeric substances (EPS) constituting a matrix that facilitates gene transfer and where bacteria exhibit high tolerance to stress and to antibiotics. In this study we implemented a sampling and analysis approach that allows phenotypic and genomic analyses of in situ and reconstituted in vitro hospital and urban wastewater (WW) biofilms. To assess the potential of hospital and urban WW biofilms to efficiently disseminate ARGs in the WW system, we explored the EPS within the biofilm matrix and assessed the expression of the resistome (ARGs) and mobilome (MGEs) by metatranscriptomics. ResultsWe first showed that a) the composition of EPS differs depending on their growth environment (in situ and in vitro) and their sampling origin (hospital vs urban WW) and that b) a low amount of ciprofloxacin impacted the composition of the EPS. Next, the metatranscriptomic approach showed that a) expression of ARGs and MGEs increase upon adding a low amount of ciprofloxacin for biofilms from hospital WW but not for those from urban WW and b) that expression of specific plasmids that carry individual or multiple ARGs varies depending on the WW origins of the biofilms. When the same plasmids were expressed in both, urban and hospital WW biofilms, they carried and expressed different ARGs. ConclusionWe show that hospital and urban wastewaters shape the structure and active resistome of environmental biofilms, and we confirmed that hospital WW is an important hot spot for the dissemination and selection of AMR. The different responses to antibiotic pressure in hospital vs urban biofilms, coupled with differences in biofilm structure helps delineate distinct characteristics of hospital and urban WW biofilms highlighting the relationships between the resistome and its expression in environmental biofilms and their surrounding ecosystems.

microbiology↗