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Formyl peptide receptor-1 (FPR1) is a pattern recognition receptor that is mostly expressed by myeloid cells. In patients with colorectal cancer (CRC), a loss-of-function polymorphism (rs867228) in the gene coding for FPR1 has been associated with reduced responses to chemotherapy or chemoradiotherapy. Moreover, rs867228 is associated with accelerated esophageal and colorectal carcinogenesis. Here, we show that dendritic cells from Fpr1 -/- mice exhibit reduced migration in response to chemotherapy-treated CRC cells. Moreover, Fpr1 -/- mice are particularly susceptible to chronic ulcerative colitis and colorectal oncogenesis induced by the mutagen azoxymethane followed by oral dextran sodium sulfate, a detergent that induces colitis. These experiments were performed after initial co-housing of Fpr1 -/- mice and wild-type controls, precluding major Fpr1-driven differences in the microbiota. Pharmacological inhibition of Fpr1 by cyclosporin H also tended to increase intestinal oncogenesis in mice bearing the Apc Min mutation, and this effect was reversed by the anti-inflammatory drug sulindac. We conclude that defective FPR1 signaling favors intestinal tumorigenesis through the modulation of the innate inflammatory/immune response., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2023 The Author(s). Published with license by Taylor & Francis Group, LLC.)

Strain Marseille-P8396 T is a new species isolated from a patient with recurrent Clostridioides difficile infection. Its optimal growth condition was observed at pH of 7.5, at a temperature of 37 °C after 72 h of incubation on Columbia agar (BioMérieux, France) with 5% sheep blood, under an anaerobic atmosphere. Strain Marseille-P8396 T cells are Gram-positive rods, nonspore-forming, and nonmotile. 9-Octadecenoic acid (41.9%), hexadecanoic acid (22.5%), and 11-Octadecenoic acid (11.0%) represent the major fatty acid of strain Marseille-P8396 T . The optimal growth condition of strain Marseille-P8396 T was observed at 37 °C after 72 h of incubation under an anaerobic atmosphere, pH ranging from 6.5 to 8.5, and salinity of 0.5 to 7.5%. Its genome (Genbank Accession Number NZ_CABDUX000000000) size was 3.86 Mb with 59.4 mol% of G+C content, and 3,124 protein-coding genes. The 16S rRNA gene sequence (Genbank accession number NR_148574.1) of strain Marseille-P8396 T shared a similarity of 98.71% with Raoultibacter timonensis strain Marseille-P3277 T (Genbank accession number NR_148574.1), currently the most closely related species. However, the OrthoANI and digital DNA-DNA hybridization values with Raoultibacter timonensis strain Marseille-P3277 T (Genbank accession number OEPT01000000) were 80.15% and 24.6 ± 4.8%, respectively. Taken together, these results clearly demonstrate that strain Marseille-P8396 T represents a new species within the genus Raoultibacter described here as Raoultibacter phocaeensis sp. nov. (type strain: Marseille-P8396 T =CSUR8396 T =CECT 30202 T )., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

After the end of the first epidemic episode of SARS-CoV-2 infections, as cases began to rise again during the summer of 2020, we at IHU Méditerranée Infection in Marseille, France, intensified the genomic surveillance of SARS-CoV-2, and described the first viral variants. In this study, we compared the incidence curves of SARS-CoV-2-associated deaths in different countries and reported the classification of SARS-CoV-2 variants detected in our institute, as well as the kinetics and sources of the infections. We used mortality collected from a COVID-19 data repository for 221 countries. Viral variants were defined based on ≥5 hallmark mutations along the whole genome shared by ≥30 genomes. SARS-CoV-2 genotype was determined for 24,181 patients using next-generation genome and gene sequencing (in 47 and 11% of cases, respectively) or variant-specific qPCR (in 42% of cases). Sixteen variants were identified by analyzing viral genomes from 9,788 SARS-CoV-2-diagnosed patients. Our data show that since the first SARS-CoV-2 epidemic episode in Marseille, importation through travel from abroad was documented for seven of the new variants. In addition, for the B.1.160 variant of Pangolin classification (a.k.a. Marseille-4), we suspect transmission from farm minks. In conclusion, we observed that the successive epidemic peaks of SARS-CoV-2 infections are not linked to rebounds of viral genotypes that are already present but to newly introduced variants. We thus suggest that border control is the best mean of combating this type of introduction, and that intensive control of mink farms is also necessary to prevent the emergence of new variants generated in this animal reservoir., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Colson, Fournier, Chaudet, Delerce, Giraud-Gatineau, Houhamdi, Andrieu, Brechard, Bedotto, Prudent, Gazin, Beye, Burel, Dudouet, Tissot-Dupont, Gautret, Lagier, Million, Brouqui, Parola, Fenollar, Drancourt, La Scola, Levasseur and Raoult.)

Since the start of COVID-19 pandemic the Republic of Djibouti, in the horn of Africa, has experienced two epidemic waves of the virus between April and August 2020 and between February and May 2021. By May 2021, COVID-19 had affected 1.18% of the Djiboutian population and caused 152 deaths. Djibouti hosts several foreign military bases which makes it a potential hot-spot for the introduction of different SARS-CoV-2 strains. We genotyped fifty three viruses that have spread during the two epidemic waves. Next, using spike sequencing of twenty-eight strains and whole genome sequencing of thirteen strains, we found that Nexstrain clades 20A and 20B with a typically European D614G substitution in the spike and a frequent P2633L substitution in nsp16 were the dominant viruses during the first epidemic wave, while the clade 20H South African variants spread during the second wave characterized by an increase in the number of severe forms of COVID-19., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Osman, Levasseur, Brechard, Abdillahi Hassan, Salah Abdillahi, Ali Waberi, Delerce, Bedotto, Houhamdi, Fournier, Colson, Aboubaker, Raoult and Devaux.)

Taxono-genomics is an innovative concept coined for the description of new bacterial species. Phenotypic characteristics were combined with a genomic approach to describe two new species within the Clostridium senso stricto genus: Clostridium culturomicium strain CL-6 T and Clostridium jeddahitimonense strain CL-2 T , both isolated from the gut microbiota of an obese man from Saudi Arabia. Strains CL-6 T and CL-2 T shared a similarity of 98.4% with the 16S rRNA gene of Clostridium subterminale strain JCM 1417 T (accession number NR113027) and 98% with that of Clostridium disporicum strain DS1 T (accession number NR026491), respectively. The highest OrthoANI values were shared with Clostridium punense for strain CL-6 T (70.8%) and with Clostridium disporicum for strain CL-2 T (87.1%). Additionally, strain CL-6 T and strain CL-2 T shared a 16S rRNA similarity of 91.4%. Both strains were anaerobic, spore-forming and Gram-stain-positive non-motile bacilli. The genome of Clostridium culturomicium strain CL-6 T is 4,325,182 bp long with 32.2% GC content. As for Clostridium jeddahitimonense strain CL-2 T , the genome is 4,074,758 bp long with 29.2% GC content., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: In Marseille, France, following a first severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak in March-May 2020, a second epidemic phase occurred from June, involving 10 new variants. The Marseille-4 variant caused an epidemic that started in August and is still ongoing., Methods: The 1038 SARS-CoV-2 whole genome sequences obtained in our laboratory by next-generation sequencing with Illumina technology were analysed using Nextclade and nextstrain/ncov pipelines and IQ-TREE. A Marseille-4-specific qPCR assay was implemented. Demographic and clinical features were compared between patients with the Marseille-4 variant and those with earlier strains., Results: Marseille-4 harbours 13 hallmark mutations. One leads to an S477N substitution in the receptor binding domain of the spike protein targeted by current vaccines. Using a specific qPCR, it was observed that Marseille-4 caused 12-100% of SARS-CoV-2 infections in Marseille from September 2020, being involved in 2106 diagnoses. This variant was more frequently associated with hypoxemia than were clade 20A strains before May 2020. It caused a re-infection in 11 patients diagnosed with different SARS-CoV-2 strains before June 2020, suggesting either short-term protective immunity or a lack of cross-immunity., Conclusions: Marseille-4 should be considered as a major SARS-CoV-2 variant. Its sudden appearance points towards an animal reservoir, possibly mink. The protective role of past exposure and current vaccines against this variant should be evaluated., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: In Marseille, France, the COVID-19 incidence evolved unusually with several successive epidemic phases. The second outbreak started in July, was associated with North Africa, and involved travelers and an outbreak on passenger ships. This suggested the involvement of a new viral variant., Methods: We sequenced the genomes from 916 SARS-CoV-2 strains from COVID-19 patients in our institute. The patients' demographic and clinical features were compared according to the infecting viral variant., Results: From June 26th to August 14th, we identified a new viral variant (Marseille-1). Based on genome sequences (n = 89) or specific qPCR (n = 53), 142 patients infected with this variant were detected. It is characterized by a combination of 10 mutations located in the nsp2, nsp3, nsp12, S, ORF3a, ORF8 and N/ORF14 genes. We identified Senegal and Gambia, where the virus had been transferred from China and Europe in February-April as the sources of the Marseille-1 variant, which then most likely reached Marseille through Maghreb when French borders reopened. In France, this variant apparently remained almost limited to Marseille. In addition, it was significantly associated with a milder disease compared to clade 20A ancestor strains, in univariate analysis., Conclusion: Our results demonstrate that SARS-CoV-2 can genetically diversify rapidly, its variants can diffuse internationally and cause successive outbreaks., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)