RESUMEN
Five obligately anaerobic, Gram-stain-negative, saccharolytic and proteolytic, non-spore-forming bacilli (strains CD3â:â27, CD3â:â28(T), CD3â:â33, CD3â:â32 and CD3â:â34) are described. All five strains were isolated from the small intestine of a female child with coeliac disease. Cells of the five strains were short rods or coccoid cells with longer filamentous forms seen sporadically. The organisms produced acetic acid and succinic acid as major metabolic end products. Phylogenetic analysis based on comparative 16S rRNA gene sequence analysis revealed close relationships between CD3â:â27, CD3â:â28(T) and CD3â:â33, between CD3â:â32 and Prevotella histicola CCUG 55407(T), and between CD3â:â34 and Prevotella melaninogenica CCUG 4944B(T). Strains CD3â:â27, CD3â:â28(T) and CD3â:â33 were clearly different from all recognized species within the genus Prevotella and related most closely to but distinct from P. melaninogenica. Based on 16S rRNA, RNA polymerase ß-subunit (rpoB) and 60 kDa chaperonin protein subunit (cpn60) gene sequencing, and phenotypic, chemical and biochemical properties, strains CD3â:â27, CD3â:â28(T) and CD3â:â33 are considered to represent a novel species within the genus Prevotella, for which the name Prevotella jejuni sp. nov. is proposed. Strain CD3â:â28(T) (â=âCCUG 60371(T)â=âDSM 26989(T)) is the type strain of the proposed novel species. All five strains were able to form homologous aggregates, in which tube-like structures were connecting individual bacteria cells. The five strains were able to bind to human intestinal carcinoma cell lines at 37 °C.
Asunto(s)
Enfermedad Celíaca/microbiología , Intestino Delgado/microbiología , Filogenia , Prevotella/clasificación , Ácido Acético/metabolismo , Técnicas de Tipificación Bacteriana , Composición de Base , Línea Celular Tumoral , Niño , ADN Bacteriano/genética , ARN Polimerasas Dirigidas por ADN/genética , Células Epiteliales/microbiología , Ácidos Grasos/química , Femenino , Humanos , Intestino Delgado/citología , Datos de Secuencia Molecular , Prevotella/genética , Prevotella/aislamiento & purificación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Ácido Succínico/metabolismo , SueciaRESUMEN
Two novel obligately anaerobic, Gram-stain-positive, saccharolytic and non-proteolytic spore-forming bacilli (strains CD3:22(T) and N1(T)) are described. Strain CD3:22(T) was isolated from a biopsy of the small intestine of a child with coeliac disease, and strain N1(T) from the saliva of a healthy young man. The cells of both strains were observed to be filamentous, approximately 5 to >20 µm long, some of them curving and with swellings. The novel organisms produced H(2)S, NH(3), butyric acid and acetic acid as major metabolic end products. Phylogenetic analyses, based on comparative 16S rRNA gene sequencing, revealed close relationships (98% sequence similarity) between the two isolates, as well as the type strain of Eubacterium saburreum and four other Lachnospiraceae bacterium-/E. saburreum-like organisms. This group of bacteria were clearly different from any of the 19 known genera in the family Lachnospiraceae. While Eubacterium species are reported to be non-spore-forming, reanalysis of E. saburreum CCUG 28089(T) confirmed that the bacterium is indeed able to form spores. Based on 16S rRNA gene sequencing, phenotypic and biochemical properties, strains CD3:22(T) and N1(T) represent novel species of a new and distinct genus, named Lachnoanaerobaculum gen. nov., in the family Lachnospiraceae [within the order Clostridiales, class Clostridia, phylum Firmicutes]. Strain CD3:22(T) (=CCUG 58757(T) =DSM 23576(T)) is the type strain of the type species, Lachnoanaerobaculum umeaense gen. nov., sp. nov., of the proposed new genus. Strain N1(T) (=CCUG 60305(T)=DSM 24553(T)) is the type strain of Lachnoanaerobaculum orale sp. nov. Moreover, Eubacterium saburreum is reclassified as Lachnoanaerobaculum saburreum comb. nov. (type strain CCUG 28089(T) =ATCC 33271(T) =CIP 105341(T) =DSM 3986(T) =JCM 11021(T) =VPI 11763(T)).