title: Lactobacillus casei, Lactobacillus rhamnosus, and Lactobacillus zeae isolates identified by sequence signature and immunoblot phenotype.
abstract: Species taxonomy within the Lactobacillus casei group of bacteria has been unsettled. With the goal of helping clarify the taxonomy of these bacteria, we investigated the first 3 variable regions of the 16S rRNA gene, the 16S-23S rRNA interspacer region, and one third of the chaperonin 60 gene for Lactobacillus isolates originally designated as L. casei, L. paracasei, L. rhamnosus, and L. zeae. For each genetic region, a phylogenetic tree was created and signature sequence analysis was done. As well, phenotypic analysis of the various strains was performed by immunoblotting. Both sequence signature analysis and immunoblotting gave immediate identification of L. casei, L. rhamnosus, and L. zeae isolates. These results corroborate and extend previous findings concerning these lactobacilli; therefore, we strongly endorse recent proposals for revised nomenclature. Specifically, isolate ATCC 393 is appropriately rejected as the L. casei type strain because of grouping with isolates identified as L. zeae. As well, because all other L. casei isolates, including the proposed neotype isolate ATCC 334, grouped together with isolates designated L. paracasei, we support the use of the single species L. casei and rejection of the name L. paracasei.
authors.affiliation: Department of Microbiology and Immunology, University of Saskatchewan, Saskatoon, Canada.
authors.forename: C Melissa
authors.initials: CM
authors.lastname: Dobson
authors.forename: Bonnie
authors.initials: B
authors.lastname: Chaban
authors.forename: Harry
authors.initials: H
authors.lastname: Deneer
authors.forename: Barry
authors.initials: B
authors.lastname: Ziola
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D018834:Chaperonin 60 / Q000235:genetics*; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000737:chemistry* / Q000302:isolation & purification; D021903:DNA, Ribosomal Spacer / Q000737:chemistry* / Q000302:isolation & purification; D020459:Genes, rRNA; D015151:Immunoblotting; D007778:Lactobacillus / Q000145:classification* / Q000235:genetics; D007780:Lacticaseibacillus casei / Q000145:classification / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D020543:Proteome / Q000032:analysis / Q000276:immunology / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
chemical_list: D001426:Bacterial Proteins; D018834:Chaperonin 60; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D020543:Proteome; D012336:RNA, Ribosomal, 16S