Enterobacter bugandensis sp. nov., from a neonatal unit in Tanzania

An ‘Enterobacter-like’ bacterium (EB-247T) isolated from an outbreak in a neonatal unit, Tanzania, could not be assigned to any known species and was further investigated. We used fermentation characteristics, biochemical assays and fatty acid profiles for taxonomic analysis of EB-247T, and supplemented this with information derived from sub-genome- and genome- based analysis. Phenotypic and morphological tests revealed that the isolate is a Gram-negative, rod-shaped, highly motile and facultatively anaerobic. Whole cell analysis showed that most of the fatty acids, with the exception of C17:0 Cyclo and C16:1?6c/C16:1?7c that were present in altered ratios, were typical for the Enterobacter species. We performed whole genome sequencing of EB-247T to perform subgenome-based phylogenetic analysis i.e. 16S rRNA, multi-locus sequence analysis (MLSA) and whole-genome-based taxonomic analysis. The draft genome of EB-247T was approximately 4.9 Mb in size with a G+C content of 56.0%. The 16S rDNA sequence of EB-247T showed > 97% similarity to all the Enterobacter species, while MLSA clustered EB-247T within Enterobacter but classified it as a separate species. Analysis using in silico DNA-DNA hybridization showed it had less than 70% sequence similarity with other Enterobacter species. The average nucleotide identity of EB-247T exhibited less than 95% sequence similarity to all the compared Enterobacter species supporting it’s a new species. From these results, we conclude that EB-247T possesses sufficient characteristics that are different from known Enterobacter species, and should be considered to be a novel species. The name Enterobacter bugandensis sp. nov. is proposed for isolate EB-247T (=DSM 29888T=NCCB 100573T).