Klebsiella michiganensis sp. nov., A New Bacterium Isolated from a Tooth Brush Holder

Isolate W14 T recovered from a household tooth brush holder was found to be gram-negative, a facultative anaerobic, non-motile, capsulated, and a non-endospore-forming straight rod. Based on phylogenetic analysis with 16S rRNA gene sequence, isolate W14 T was affiliated to the genus Klebsiella . The closest phylogenetic relative was K. oxytoca with 99 % similarity in the 16S rRNA gene sequence. The major whole-cell fatty acids were C 16:0 (31.23 %), C 18:1ω6c /C 18:1ω7c (21.10 %), and C 16:1ω7c /C 16:1ω6c (19.05 %). The sequence similarities of isolate W14 T based on rpoB , gyrA , and gyrB were 97, 98, and 98 % with K. oxytoca , and 97, 93, and 90 % with K. mobilis (= Enterobacter aerogenes ), respectively. The ribotyping pattern showed a 0.46 similarity with K. oxytoca ATCC 13182 T and 0.24 with K. mobilis ATCC 13048 T . The DNA G+C content of isolate W14 T was 54.6 mol%. The DNA–DNA relatedness was 55.7 % with K. oxytoca ATCC 13182 T . Using the identification technology of MALDI-TOF mass spectrometry, the top matches for this isolate were K. oxytoca ATCC 13182 T (Match Factor Score 1.998) and K. mobilis (Score 1.797). On the basis of phenotypic, biochemical, chemotaxonomic, and molecular studies, isolate W14 T could be differentiated from other members of the genus Klebsiella including K. mobilis . Therefore, it is proposed that isolate W14 T (=ATCC BAA-2403 T =DSM 25444 T ) should be classified as the type strain of a novel species of the genus Klebsiella , K. michiganensis sp. nov.