Isaure Quétel

Background: Bioinformatics is increasingly used in various scientific works. Large amounts of heterogeneous data are being generated these days. It is difficult to interpret and analyze these data effectively. Several software tools have been developed to facilitate the handling and analysis of biological data, based on specific needs. Methods: The Galaxy web platform is one of these software tools, allowing free access to users and facilitating the use of thousands of tools. Other software tools, such as Bioconda or Jupyter Notebook, facilitate the installation of tools and their dependencies. In addition to these tools, RStudio can be mentioned as a powerful interface that facilitates the use of the R programming language for data analysis and statistics. Results: The aim of this study is to provide the scientific community with guides on how to perform bioinformatics/biostatistical analyses in a simpler manner. With this work, we also try to democratize well-documented software tools to make them suitable for both bioinformaticians and non-bioinformaticians. We believe that user-friendly guides and real-life/concrete examples will provide end-users with suitable and easy-to-use methods for their bioinformatics analysis needs. Furthermore, tutorials and usage examples are available on our dedicated GitHub repository. Conclusions: These tutorials/examples (In English and/or French) could be used as pedagogical tools to promote bioinformatics analysis and offer potential solutions to several bioinformatics needs. Special emphasis is placed on microbial omics data analysis.

Waterborne faecal contamination is a major public health concern. The main objectives of this study were to investigate faecal contamination and Escherichia coli (E. coli) antibiotic resistance in recreational fresh water from Guadeloupe and to characterise the microbiome and resistome composition in biofilms from submerged rocks. Significant faecal contamination was observed at 14 freshwater sites. E. coli predominated (62%), followed by Enterobacter cloacae (11%) and Acinetobacter spp. (11%). Of 152 E. coli isolated, none produced extended-spectrum beta-lactamases (ESBLs), but 7% showed resistance to streptomycin and 4% to tetracycline. Biofilm resistome analysis revealed clinically significant antibiotic-resistance genes (ARGs), including those coding for resistance to sulfonamides (sul1), carbapenems (bla_KPC), and third-generation cephalosporins (bla_CTX-M). Mobile genetic elements (MGEs) (intI1, intI2, intI3) linked to resistance to aminoglycosides, beta-lactams, tetracycline, as well as heavy metal resistance determinants (copA, cusF, czcA, merA) conferring resistance to copper, silver, cadmium, and mercury were also detected. Diverse bacterial phyla were found in biofilm samples, of which Proteobacteria, Bacteroidetes, Planctonomycetes, and Cyanobacteria were predominant. Despite the frequent presence of E. coli exceeding regulatory standards, the low levels of antibiotic-resistant bacteria in freshwater and of ARGs and MGEs in associated biofilms suggest limited antibiotic resistance in Guadeloupean recreational waters.

Sequential membrane filtration of water samples is commonly used to monitor the diversity of aquatic microbial eukaryotes. This capture method is efficient to focus on specific taxonomic groups within a size fraction, but it is time‐consuming. Centrifugation, often used to collect microorganisms from pure culture, could be seen as an alternative to capture microbial eukaryotic communities from environmental samples. Here, we compared the two capture methods to assess diversity and ecological patterns of eukaryotic communities in the Thau lagoon, France. Water samples were taken twice a month over a full year and sequential filtration targeting the picoplankton (0.2–3 μm) and larger organisms (>3 μm) was used in parallel to centrifugation. The microbial eukaryotic community in the samples was described using an environmental DNA approach targeting the V4 region of the 18S rRNA gene. The most abundant divisions in the filtration fractions and the centrifugation pellet were Dinoflagellata, Metazoa, Ochrophyta, Cryptophyta. Chlorophyta were dominant in the centrifugation pellet and the picoplankton fraction but not in the larger fraction. Diversity indices and structuring patterns of the community in the two size fractions and the centrifugation pellet were comparable. Twenty amplicon sequence variants were significantly differentially abundant between the two size fractions and the centrifugation pellet, and their temporal patterns of abundance in the two fractions combined were similar to those obtained with centrifugation. Overall, centrifugation led to similar ecological conclusions as the two filtrated fractions combined, thus making it an attractive time‐efficient alternative to sequential filtration.