Reclassification of Bacteroides putredinis (Weinberg et al., 1937) in a new genus Alistipes gen. nov., as Alistipes putredinis comb. nov., and description of Alistipes finegoldii sp. nov., from human sources.
During studies on the bacteriology of appendicitis in children, we often isolated from inflamed and non-inflamed tissue samples, an unusual bile-resistant pigment-producing strictly anaerobic gram-negative rod. Phenotypically this organism resembles members of Bacteroides fragilis group of species, as it is resistant to bile and exhibits a special-potency-disk pattern (resistance to vancomycin, kanamycin and colistin) typical for the B. fragilis group. However, the production of brown pigment on media containing haemolysed blood and a cellular fatty acid composition dominated by iso-C15:0, suggests that the organism most closely resembles species of the genus Porphyromonas. However, the unidentified organism differs from porphyromonads by being bile-resistant and by not producing butyrate as a metabolic end-product. Comparative 16S ribosomal RNA gene sequencing studies show the unidentified organism represents a distinct sub-line, associated with but distinct from, the miss-classified species Bacteroides putredinis. The clustering of the unidentified bacterium with Bacteroides putredinis was statistically significant, but they displayed > 4% sequence divergence with each other. Chromosomal DNA-DNA pairing studies further confirmed the separateness of the unidentified bacterium and Bacteroides putredinis. Based on phenotypic and phylogenetic considerations, it is proposed that Bacteroides putredinis and the unidentified bacterium from human sources be classified in a new genus Alistipes, as Alistipes putredinis comb. nov. and Alistipes finegoldii sp. nov., respectively. The type strain of Alistipes finegoldii is CCUG 46020(T) (= AHN243(T)).
Rautio
Merja
M
National Public Health Institute (KTL), Department of Microbiology, Anaerobe Reference Laboratory, Helsinki, Finland. merja.rautio@ktl.fi
Eerola
Erkki
E
Väisänen-Tunkelrott
Marja-Liisa
ML
Molitoris
Denise
D
Lawson
Paul
P
Collins
Matthew D
MD
Jousimies-Somer
Hannele
H
D001064:Appendicitis / Q000382:microbiology*; D015373:Bacterial Typing Techniques; D001439:Bacteroides / Q000737:chemistry / Q000145:classification* / Q000302:isolation & purification; D001646:Bile / Q000382:microbiology; D002648:Child; D004269:DNA, Bacterial / Q000235:genetics; D004761:Enterocolitis, Pseudomembranous / Q000382:microbiology; D005227:Fatty Acids / Q000032:analysis; D005243:Feces / Q000382:microbiology; D006090:Gram-Negative Bacteria / Q000145:classification*; D006801:Humans; D007787:Lactose Intolerance / Q000382:microbiology; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010860:Pigments, Biological / Q000032:analysis; D017861:Porphyromonas / Q000737:chemistry; D021521:Ribotyping; D013045:Species Specificity; D009626:Terminology as Topic
D004269:DNA, Bacterial; D005227:Fatty Acids; D010860:Pigments, Biological