The skin microbiota : exploratory analysis of its composition and variation with age in adult women

On compte deux stratégies principales permettant la culture de microorganismes « difficiles à cultiver », la première repose sur la supplémentation, la personnalisation ou la modification des milieux d'isolement et de culture, et la seconde sur le mimétisme des conditions de croissance en milieu naturel. Fondé sur le principe de cette dernière approche, nous avons développé et utilisé dans cette étude un nouveau milieu sélectif nommé MB2L afin d’isoler et de sélectionner des bactéries cutanées dont la croissance est masquée par les principales espèces cutanées (telles que Staphylococcus). Cette étude à permis de montrer une différence de la composition du microbiote entre les deux groupes d'âge et également d’isoler 20 nouvelles espèces bactériennes jamais décrites auparavant. L'analyse du portage par qPCR de ces nouvelles espèces bactériennes a été reliasse sur de larges populations. Cette analyse a permis de déterminer si ces bactéries étaient commensales ou transitoires. Sur nos 20 nouvelles espèces bactériennes, sept ont été déterminées comme commensales, donc potentiellement d’intérêt particulier pour des investigations plus poussées sur leurs rôles et leur interaction avec la peau, via la coculture utilisant des modèles cutanés 3D. Ces organismes sont le point de départ des investigations futures qui visent à mettre en évidence leur potentiel rôle bénéfique pour la peau et ainsi les utiliser comme probiotiques et postbiotiques. Aussi, nous avons recherché de nouveaux composés bioactifs sécrétés par ces bactéries Ces nouveaux organismes pourraient également être le substrat d’identification de composés prébiotiques.Among the methods described as allowing the cultivation of microorganisms considered as "difficult to cultivate", one of the first strategies is based on the supplementation, customization or modification of isolation and culture media, and another is based on the mimicry of growth conditions in the natural environment. The MB2L medium was developed and used in this study to isolate and select skin bacteria whose growth is masked by the main skin species (such as Staphylococcus). In this study, in addition to showing a preferential pattern of carriage of different bacterial species between the two age groups, we isolated 20 new bacterial species never described before. Carriage analysis by qPCR of these new bacterial species was performed on large panels. This analysis made it possible to determine whether these bacteria were commensal or transient. Of our 20 novel bacterial species, 7 were determined as commensals, so potentially of greater interest for further investigations of their roles or what they could produce, and their interaction with the skin, notably through the coculture with 3D skin models. These organisms are the starting point of future investigations that aim to discover their potential beneficial role for the skin and create expectations for their use as probiotic and postbiotic or the discovery of new bacterial-derivate bioactive compounds (for the use as postbiotic), they could also be the substrate for experimental determination of prebiotic compounds

Has doxycycline, in combination with anti-malarial drugs, a role to play in intermittent preventive treatment of Plasmodium falciparum malaria infection in pregnant women in Africa?

International audienceAccording to the World Health Organization (WHO), Plasmodium falciparum malaria during pregnancy is responsible for deleterious consequences for the mother and her child. The administration of intermittent preventive treatment (IPTp) with sulfadoxine-pyrimethamine (SP) at each antenatal care visit as early as 13weeks of gestation until the time of delivery is a strategy that is currently recommended by WHO for the prevention of malaria in pregnancy. However, the emergence and the spread of the resistance to SP in Africa raise the question of the short-term effectiveness of the strategy. Dihydroartemisinin-piperaquine 120mg/960mg once a day for 3consecutive days administered at least three times during the pregnancy might be an option for IPTp. The combination of 200mg of doxycycline once a day for 3consecutive days seems to be a good option to retard the emergence and the spread of resistance to artemisinin-based combination therapy (ACT) in Africa and improve the effectiveness of ACT in term of preterm births, neonatal morbidity and mortality. Contrary to preconceived ideas, scientific and medical data suggest that the risk of congenital malformations in the fetus or of tooth staining in infants whose mothers take doxycycline and hepatotoxicity during pregnancy is very low or non-existent. Additionally, the use of doxycycline during the first and second trimesters leads to an increase in gestational age at delivery, a decrease in the number of preterm births and a reduction in neonatal morbidity and mortality due to the beneficial antimicrobial activity of doxycycline against other infections during pregnancy. Furthermore, doxycycline has anti-malarial properties and is already recommended as prophylaxis for travellers and for treatment of falciparum malaria in combination with other anti-malarial drugs

Challenges in exploring and manipulating the human skin microbiome

International audienceAbstract The skin is the exterior interface of the human body with the environment. Despite its harsh physical landscape, the skin is colonized by diverse commensal microbes. In this review, we discuss recent insights into skin microbial populations, including their composition and role in health and disease and their modulation by intrinsic and extrinsic factors, with a focus on the pathobiological basis of skin aging. We also describe the most recent tools for investigating the skin microbiota composition and microbe-skin relationships and perspectives regarding the challenges of skin microbiome manipulation

Isolation and Description of Catonella massiliensis sp. nov., a Novel Catonella Species, Isolated from a Stable Periodontitis Subject

International audienceThe genus Catonella currently counts a unique species, C. morbi, isolated from periodontal pockets and associated with periodontitis and endodontic infections. This study contributed to the taxonomical and clinical knowledge of this genus by describing a novel species isolated from a saliva sample from a man in clinical gingival health following successful treatment of periodontitis. Morphological and chemotaxonomic characteristics were investigated using different growth conditions, pH, and temperature. Cellular fatty acid methyl ester (FAME) analysis was conducted by gas chromatography/mass spectrometry (GC/MS). Phylogenetic analysis based on 16S rRNA, orthologous average nucleotide identity (OrthoANI), and digital DNA-DNA hybridization (dDDH) relatedness were performed. Strain Marseille-Q4567T was found to be an anaerobic and non-spore-forming rod-shaped bacterium that grew at 28–41.5 °C (optimum 37 °C), pH 6.5–8.5 (optimum pH 7.5), and 5–10 g/L of NaCl (optimum 5 g/L). The predominant cellular fatty acid was C16:0 (64.2%), followed by unsaturated structures C18:1n9 (12.5%) and C18:2n6 (7.8%). Based on 16S rRNA sequence comparison, the closest phylogenetic neighbor was C. morbi ATCC 51271T (98.23% similarity). The OrthoANI and dDDH values between strain Q4567T and C. morbi ATCC 51271T were respectively 79.43% and 23.8%. Therefore, we concluded that strain Marseille-Q4567T represents a novel species of the genus Catonella, for which the name Catonella massiliensis sp. nov. is proposed (= CSUR Q4567)

Isolation and Characterization of Capnocytophaga bilenii sp. nov., a Novel Capnocytophaga Species Detected in a Gingivitis Subject

International audienceCapnocytophaga species are commensal gliding bacteria that are found in human and animal oral microbiota and are involved in several inflammatory diseases, both in immunocompromised and immunocompetent subjects. This study contributes to increased knowledge of this genus by characterizing a novel species isolated from a dental plaque sample in a male with gingivitis. We investigated morphological and chemotaxonomic characteristics using different growth conditions, temperature, and pH. Cellular fatty acid methyl ester (FAME) analysis was employed with gas chromatography/mass spectrometry (GC/MS). Phylogenetic analysis based on 16S rRNA, orthologous average nucleotide identity (OrthoANI), and digital DNA–DNA hybridization (dDDH) relatedness were performed. The Marseille-Q4570T strain was found to be a facultative aerobic, Gram-negative, elongated, round-tipped bacterium that grew at 25–56 °C and tolerated a pH of 5.5 to 8.5 and an NaCl content ranging from 5 to 15 g/L. The most abundant fatty acid was the branched structure 13-methyl-tetradecanoic acid (76%), followed by hexadecanoic acid (6%) and 3-hydroxy-15-methyl-hexadecanoic acid (4%). A 16S rDNA-based similarity analysis showed that the Marseille-Q4570T strain was closely related to Capnocytophaga leadbetteri strain AHN8855T (97.24% sequence identity). The OrthoANI and dDDH values between these two strains were, respectively, 76.81% and 25.6%. Therefore, we conclude that the Marseille-Q4570T strain represents a novel species of the genus Capnocytophaga, for which the name Capnocytophaga bilenii sp. nov. is proposed (=CSUR Q4570)

Draft Genome Sequence of Streptomyces mexicanus Strain Q0842, Isolated from Human Skin

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Isolation and Characterization of Kingella bonacorsii sp. nov., A Novel Kingella Species Detected in a Stable Periodontitis Subject

International audienceMembers of the genus Kingella are mostly commensals of the oral cavity, but some of them are involved in invasive infections, especially in young children. This study provides new knowledge on the diversity of this genus by describing a novel species of Kingella isolated from a dental plaque sample from a 51-year-old man with a history of periodontitis. Morphological and chemotaxonomic characteristic were investigated using different growth conditions, pH and temperature. Cellular fatty acid methyl ester (FAME) analysis was performed by gas chromatography/mass spectrometry (GC/MS). Phylogenetic analysis based on 16S rRNA, orthologous average nucleotide identity (OrthoANI) and digital DNA–DNA hybridization (dDDH) relatedness were also performed. Strain Marseille-Q4569T was found to be a facultative aerobic, nonmotile and non-spore-forming rod-shaped bacterium that grows at 28–41.5 °C (optimum 37 °C), pH 5.5–8.5 (optimum pH 7.5) and 5–15 g/L of NaCl. The major fatty acids were Hexadecanoic acid (32.7%), 11-Octadecenoic acid (26.1 %) and 9-Hexadecenoic acid (21.3 %). Despite high 16S rRNA gene sequence similarity (98.72%) between strain Marseille-Q4569T and Kingella oralis strain UB-38T, the degree of OrthoANI was at the limit of the cutoff (95.83%), and the degree of dDDH was lower (63.6%) than thresholds used to delineate prokaryotic species. Therefore, it is proposed that strain Marseille-Q4569T represents a novel species of the genus Kingella, for which the name Kingella bonacorsii sp. nov. is proposed (=CSUR Q4569)

Isolation and description of Selenomonas timonae sp. nov., a novel Selenomonas species detected in a gingivitis patient

International audienceA Gram-stain-negative bacterium, designated strain Marseille-Q3039 T , was isolated from subgingival dental plaque of a woman with gingivitis in Marseille, France. Strain Marseille-Q3039 T was found to be an anaerobic, motile and spore-forming crescent-shaped bacterium that grew at 25–41.5 °C (optimum, 37 °C), pH 5.5–8.5 (optimum, pH 7.5) and salinity of 5.0 g l −1 NaCl. The results of 16S rRNA gene sequence analysis revealed that strain Marseille-Q3039 T was closely related to Selenomonas infelix ATCC 43532 T (98.42 % similarity), Selenomonas dianae ATCC 43527 T (97.25 %) and Centipedia periodontii DSM 2778 T (97.19 %). The orthologous average nucleotide identity and digital DNA–DNA hybridization relatedness between strain Q3039 T and its closest phylogenetic neighbours were respectively 84.57 and 28.2 % for S. infelix ATCC 43532 T and 83.93 and 27.2 % for C. periodontii DSM 2778 T . The major fatty acids were identified as C 13 : 0 (27.7 %), C 15 : 0 (24.4 %) and specific C 13 : 0 3-OH (12.3 %). Genome sequencing revealed a genome size of 2 351 779 bp and a G+C content of 57.2 mol%. On the basis of the results from phenotypic, chemotaxonomic, genomic and phylogenetic analyses and data, we concluded that strain Marseille-Q3039 T represents a novel species of the genus Selenomonas , for which the name Selenomonas timonae sp. nov. is proposed (=CSUR Q3039=CECT 30128)

Case Report: Clostridium neonatale Bacteremia in a Preterm Neonate With Necrotizing Enterocolitis

International audienceNecrotizing enterocolitis is a life-threatening acquired gastrointestinal disorder among preterm neonates and is associated with a high mortality rate and long-term neurodevelopmental morbidity. No etiologic agent has been definitively established; nonetheless, the most implicated bacteria include members of the Clostridium genus. We reported here on a case of Clostridium neonatale bacteremia in a preterm neonate with necrotizing enterocolitis, providing more information regarding the potential role of this bacterium in pathogenesis of necrotizing enterocolitis. We emphasized the sporulating form of C. neonatale that confers resistance to disinfectants usually applied for the hospital environmental cleaning. Further works are needed to establish the causal relationship between the occurrence of NEC and the isolation of C. neonatale , with promising perspectives in terms of diagnostic and therapeutic management

Leucobacter manosquensis sp. nov.—A Novel Bacterial Species Isolated from Healthy Human Skin

International audienceExtending our knowledge on human skin microbiota is a challenge to better decipher its role in health and disease. Using the culturomics method, we isolated strain Marseille-Q4368 from the healthy forehead of a 59-year-old woman. We describe here the main characteristics of this bacterium using a taxonogenomic approach. This new bacterial species is Gram-positive, non-motile, and non-spore-forming. Its 16S rRNA sequence exhibited a similarity of 99.59% with Leucobacter chromiiresistens, the most closely related species in terms of nomenclature. However, a digital DNA–DNA hybridization analysis between these two species revealed a maximum identity similarity of only 27.5%. We found phenotypical and genomic differences between strain Marseille-Q4368 and its closely related species. These findings underscore the classification of this bacterium as a distinct species. Hence, we propose the name Leucobacter manosquensis sp. nov. strain Marseille-Q4368 (=CSUR Q4368 = DSM 112403) for this newly identified bacterial species