What's in a Name? New Bacterial Species and Changes to Taxonomic Status from 2012 through 2015

Technological advancements in fields such as molecular genetics and the human microbiome have resulted in an unprecedented recognition of new bacterial genus/species designations by the International Journal of Systematic and Evolutionary Microbiology Knowledge of designations involving clinically significant bacterial species would benefit clinical microbiologists in the context of emerging pathogens, performance of accurate organism identification, and antimicrobial susceptibility testing. In anticipation of subsequent taxonomic changes being compiled by the Journal of Clinical Microbiology on a biannual basis, this compendium summarizes novel species and taxonomic revisions specific to bacteria derived from human clinical specimens from the calendar years 2012 through 2015.

Geodermatophilus telluris sp. nov., an actinomycete isolated from Saharan desert sand

A novel Gram-positive, multiloculated thalli-forming, aerobic, actinobacterial strain, CF9/1/1T, was isolated in 2007 during environmental screening for xerophilic fungi in arid desert soil from the Sahara desert, Chad. The isolate grew best at a temperature range of 20–35 °C and at pH 6.0–8.5 and with 0–4 % (w/v) NaCl, forming black-coloured and irregular colonies on GYM agar. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Geodermatophilus . The DNA G+C content of the novel strain was 75.4 mol%. The peptidoglycan contained meso-diaminopimelic acid as a diagnostic diamino acid. The main phospholipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, a not yet structurally identified aminophospholipid and a small amount of phosphatidylglycerol; MK-9(H4) was identified as the dominant menaquinone and galactose was a diagnostic sugar. The major cellular fatty acids were branched-chain saturated acids: iso-C16 : 0 and iso-C15 : 0. The 16S rRNA gene sequence of the isolate showed 94.6–97.0 % sequence similarities with those of five members of the genus: Geodermatophilus ruber DSM 45317T (94.6 %), Geodermatophilus obscurus DSM 43160T (94.8 %), Geodermatophilus siccatus DSM 45419T (96.2 %), Geodermatophilus nigrescens DSM 45408T (96.7 %) and Geodermatophilus arenarius DSM 45418T (97.0 %). Based on the evidence from this polyphasic taxonomic study, a novel species, Geodermatophilus telluris sp. nov., is proposed; the type strain is CF9/1/1T ( = DSM 45421T = CCUG 62764T).

Geodermatophilus normandii sp. nov., isolated from Saharan desert sand

A novel Gram-reaction-positive actinobacterial strain, designated CF5/3(T), was isolated from a sand sample obtained in the Sahara Desert, Chad. The greenish-black-pigmented isolate was aerobic and exhibited optimal growth from 25-40 °C at pH 6.0-10.0 with 0-1% (w/v) NaCl. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Geodermatophilus. The DNA G+C content of the genome of the novel strain was 75.5 mol%. The peptidoglycan contained meso-diaminopimelic acid as diagnostic diamino acid. The main phospholipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and a minor fraction of phosphatidylglycerol. MK-9(H4) was the dominant menaquinone, and galactose was detected as a diagnostic sugar. The major cellular fatty acids were branched-chain saturated acids: iso-C(15:0) and iso-C(16:0). Analysis of 16S rRNA gene sequences showed 95.6-98.8% pairwise sequence identity with the members of the genus Geodermatophilus. Based on phenotypic and chemotaxonomic properties, as well as phylogenetic distinctiveness, the isolate represents a novel species, Geodermatophilus normandii, with the type strain CF5/3(T) ( =DSM 45417(T) =CCUG 62814(T) =MTCC 11412(T)).