Systematic 16S rRNA Gene Sequencing of Atypical Clinical Isolates Identified 27 New Bacterial Species Associated with Humans

Abstract

ABSTRACT Clinical microorganisms isolated during a 5-year study in our hospital that could not be identified by conventional criteria were studied by 16S rRNA gene sequence analysis. Each isolate yielded a ≥1,400-bp sequence containing <5 ambiguities which was compared with the GenBank 16S rRNA gene library; 1,404 such isolates were tested, and 120 were considered unique (27 isolates) or rare (≤10 cases reported in the literature) human pathogens. Eleven new species, “ Actinobaculum massiliae ,” “ Candidatus Actinobaculum timonae,” Paenibacillus sanguinis , “ Candidatus Bacteroides massiliae,” Chryseobacterium massiliae , “ Candidatus Chryseobacterium timonae,” Paenibacillus massiliensis , “ Candidatus Peptostreptococcus massiliae,” “ Candidatus Prevotella massiliensis,” Rhodobacter massiliensis , and “ Candidatus Veillonella atypica” were identified. Sixteen species were obtained from humans for the first time. Our results show the important role that 16S rRNA gene sequence-based bacterial identification currently plays in recognizing unusual and emerging bacterial diseases.