Evaluating the serological status of COVID-19 patients using an indirect immunofluorescent assay, France.

An indirect in-house immunofluorescent assay was developed in order to assess the serological status of COVID-19 patients in Marseille, France. Performance of IFA was compared to a commercial ELISA IgG kit. We tested 888 RT-qPCR-confirmed COVID-19 patients (1302 serum samples) and 350 controls including 200 sera collected before the pandemic, 64 sera known to be associated with nonspecific serological interference, 36 sera from non-coronavirus pneumonia and 50 sera from patient with other common coronavirus to elicit false-positive serology. Incorporating an inactivated clinical SARS-CoV-2 isolate as the antigen, the specificity of the assay was measured as 100% for IgA titre ≥ 1:200, 98.6% for IgM titre ≥ 1:200 and 96.3% for IgG titre ≥ 1:100 after testing a series of negative controls. IFA presented substantial agreement (86%) with ELISA EUROIMMUN SARS-CoV-2 IgG kit (Cohen's Kappa = 0.61). The presence of antibodies was then measured at 3% before a 5-day evolution up to 47% after more than 15 days of evolution. We observed that the rates of seropositivity as well as the titre of specific antibodies were both significantly higher in patients with a poor clinical outcome than in patients with a favourable evolution. These data, which have to be integrated into the ongoing understanding of the immunological phase of the infection, suggest that detection anti-SARS-CoV-2 antibodies is useful as a marker associated with COVID-19 severity. The IFA assay reported here is useful for monitoring SARS-CoV-2 exposure at the individual and population levels.

Detailed description of Senegalia massiliensis strain SIT17T , a bacterium isolated from the human gut.

Strain SIT17T was isolated from the stool of a healthy 13-month-old Senegalese boy. It is a Gram-positive, anaerobic, rod-shaped, non-spore-forming and mobile bacterium. It exhibited 92.74% 16S rRNA gene sequence similarity with the Brassicibacter thermophilus strain Cel2f, the phylogenetically most closely related species. Its genome is about 2.87 Mb long with 27.39 mol% G + C content. We provide more details of Senegalia massiliensis strain SIT17T (= CSURP2130 = DSM 103071), the creation of which was previously announced.

The hypervirulent Coxiella burnetii Guiana strain compared in silico, in vitro and in vivo to the Nine Mile and the German strain.

OBJECTIVE: Q fever epidemic outbreaks have been reported in French Guiana and in The Netherlands. To determine whether the C. burnetii strains involved in these epidemics had a peculiar virulence pattern, we compared the pathogenicity of the Guiana and the German strain (a clone of The Netherlands strain), in silico, in vitro, and in vivo versus the Nine Mile strain. METHOD: The pan-genomes of the Guiana (Cb175), German (Z3055), and the referent Nine Mile (RSA 493) C. burnetii strains were compared. In vitro, the growth rate and the morphological presentation were compared. In vivo (SCID and Balb/c mice), weight loss, histological lesions, C. burnetii bacterial load in deep organs, and serological response were reported according to each C. burnetii strain studied. RESULTS: The Guiana strain had 77 times more missing genes and 12 times more unique genes than the German strain. The Guiana strain presented as large cell variants (LCVs) and led to the most pronounced fatality rate in SCID mice (100% at 4 weeks). The German strain presented as small cell variants (SCVs), and had an intermediate fatality rate (75% at 4 weeks). Both the Guiana and the German strains led to a significant higher serological response at 2 and 4 weeks post infection (p <0.05). CONCLUSION: The Guiana strain was the most virulent strain, followed by the German strain and the referent Nine Mile strain. Unique and missing genes could be implicated but further investigations are necessary to specify their role.

'Cellulomonas timonensis' sp. nov., taxonogenomics description of a new bacterial species isolated from human gut.

'Cellulomonas timonensis' sp. nov. strain sn7T is a new species within the Cellulomonas genus. We present the main phenotypic characteristics and provide a complete annotation of its genome sequence. This facultative anaerobic bacterium, isolated from the stool of 38-year-old obese Frenchman, is Gram-positive, has motile rods and is sporulating. The genome is 4 057 828 bp long with 72.42% G + C content. Of the 3732 predicted genes, 3667 were protein-coding genes and 65 were RNAs.

Noncontiguous finished genome sequences and description of Bacillus massiliglaciei, Bacillus mediterraneensis, Bacillus massilinigeriensis, Bacillus phocaeensis and Bacillus tuaregi, five new species identified by culturomics.

Microbial culturomics, which investigates microbial diversity by combining diversified culture conditions, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rDNA identification, allowed to identify five new species within the Bacillus genus. Bacillus massiliglaciei strain Marseille-P2600T, Bacillus mediterraneensis strain Marseille-P2384T, Bacillus massilinigeriensis strain Marseille-P2366T, Bacillus tuaregi strain Marseille-P2489T and Bacillus phocaeensis strain SIT16T are each the type strain of the corresponding bacterial species. These strains, the genomes of which are described here, are facultative anaerobic Gram-positive bacilli. Here, we describe the main characteristics of each bacterium and present their complete genome sequence and annotation.

Noncontiguous finished genome sequence and description of Prevotella phocaeensis sp. nov., a new anaerobic species isolated from human gut infected by Clostridium difficile.

Prevotella phocaeensis sp. nov. strain SN19T (= DSM 103364) is a new species isolated from the gut microbiota of patient with colitis due to Clostridium difficile. Strain SN19T is Gram-negative rod-shaped bacteria, strictly anaerobic, nonmotile and non-endospore forming. The predominance fatty acid is hexadecanoic acid. Its 16S rRNA showed a 97.70% sequence identity with its phylogenetically closest species, Prevotella oralis. The genome is 2 922 117 bp long and contains 2486 predicted genes including 56 RNA genes.

Corynebacterium phoceense sp. nov., strain MC1T a new bacterial species isolated from human urine.

Corynebacterium phoceense strain MC1 (= CSUR P1905 = DSM 100570) is a novel Corynebacterium species isolated from the urine of a kidney transplant recipient as a part of a culturomics study. Corynebacterium phoceense is a Gram-positive, sporogenous, strictly aerobic, and nonmotile coccobacillus. Here we describe strain MC1 and provide its complete annotated genome sequence according to the taxonogenomics concept. Its genome is 2 793 568 bp long and contains 2575 protein-coding genes and 67 RNA genes, including eight rRNA genes.

Noncontiguous finished genome sequence and description of Murdochiella massiliensis strain SIT12 sp. nov.

Murdochiella massiliensis strain SIT12 (= CSUR P1987 = DSM 29078) is the type strain of M. massiliensis sp. nov. This bacterium was isolated from the stool of a healthy 2-year-old Senegalese boy. M. massiliensis is an anaerobic, Gram-positive coccus. The genome size of M. massiliensis strain SIT12 is 1 642 295 bp with 48.9% G+C content and assembled into two scaffolds.

Noncontiguous finished genome sequence and description of Planococcus massiliensis sp. nov., a moderately halophilic bacterium isolated from the human gut.

We propose the main phenotypic characteristics and the complete genome sequence and annotation of Planococcus massiliensis strain ES2(T) (= CSUR P1103 = DSM 28915), the type strain of P. massiliensis sp. nov., isolated from a faeces sample collected from a healthy Senegalese man. It is an aerobic, Gram-positive, moderately halophilic, motile and rod-shaped bacterium. The 3 357 017 bp long genome exhibits a G+C content of 46.0% and contains 3357 protein-coding genes and 48 RNA genes.

Noncontiguous finished genome sequence and description of Virgibacillus massiliensis sp. nov., a moderately halophilic bacterium isolated from human gut.

Strain Vm-5(T) was isolated from the stool specimen of a 10-year-old Amazonian boy. This bacterium is a Gram-positive, strictly aerobic rod, motile by a polar flagellum. Here we describe its phenotypic characteristics and complete genome sequence. The 4 353 177 bp long genome exhibits a G + C content of 36.87% and contains 4394 protein-coding and 125 predicted RNA genes. Phylogenetically and genetically, strain Vm-c is a member of the genus Virgibacillus but is distinct enough to be classified as a new species. We propose the creation of V. massiliensis sp. nov., whose type strain is strain Vm-5(T) (CSUR P971 = DSM 28587).

Virgibacillus senegalensis sp. nov., a new moderately halophilic bacterium isolated from human gut.

Virgibacillus senegalensis SK-1(T) (= CSUR P1101 = DSM 28585) is the type strain of V. senegalensis sp. nov. It is an aerobic, Gram positive, moderately halophilic, motile bipolar flagellum isolated from a healthy Senegalese man. Here we describe the genomic and phenotypic characteristics of this isolate. The 3 755 098 bp long genome (one chromosome, no plasmid) exhibits a G + C content of 42.9% and contains 3738 protein-coding and 95 RNA genes.