Polyphasic taxonomic approach in the description of Alishewanella fetalis gen. nov., sp nov., isolated from a human foetus

A taxonomically unique bacterium is described on the basis of a physiologic al and biochemical characterization, fatty acid profiling and sequence anal yses of 16S rRNA and gyrase B (gyrB) genes. This non-motile, non-fermentati ve bacterium was isolated from a human foetus in Uppsala, Sweden, and origi nally misidentified as ii Shewanella putrefaciens by conventional biochemic al testing. The bacterium grew well at mesophilic temperatures with optimum growth at 37 degrees C. It was facultatively anaerobic and utilized variou s electron accepters (trimethylamine oxide, nitrate, nitrite and thiosulpha te). The dominant fatty acids were 17:1B, 16:1 cis9 17:0 and 16:0. Fatty ac ids 13:0 iso and 15:0 iso, which have been found to be typical of Shewanell a species were not detected. The G+C content of the DNA was 50.6 mol%. Phyl ogenetic analysis of the 16S rRNA gene sequence revealed a clear affiliatio n with members of the gamma subclass of the Proteobacteria. No relationship was seen with any of the established genera in the gamma subclass of the P roteobacteria, although a distinct relationship with Vibrionaceae was obser ved. That the bacterium represents a novel bacterial genus distinct from Vi brionaceae was also supported by gyrB sequence analysis. Considering the so urce and close proximity to the genus Shewanella, the name Alishewanella fe talis gen. nov., sp. nov. is proposed, for which the type strain is strain CCUG 30811(T).