Arsenophonus apicola sp. nov., isolated from the honeybee Apis mellifera .

The genus has been traditionally considered to comprise heritable bacterial symbionts of arthropods. Recent work has reported a microbe related to the type species as infecting the honey bee, . The association was unusual for members of the genus in that the microbe-host interaction arose through environmental and social exposure rather than vertical transmission. In this study, we describe the culture of ArsBeeUS, a strain of this microbe isolated from in the USA. The 16S rRNA sequence of the isolated strain indicates it falls within the genus . Biolog analysis indicates the bacterium has a restricted range of nutrients that support growth. experiments demonstrate the strain proliferates rapidly on injection into hosts. We further report the closed genome sequence for the strain. The genome is 3.3 Mb and the G+C content is 37.6 mol%, which is smaller than but larger than the genomes reported for non-culturable symbionts. The genome is complex, with six extrachromosomal elements and 11 predicted intact phage elements, but notably less complex than . Strain ArsBeeUS is clearly distinct from the type species on the basis of genome sequence, with 92 % average nucleotide identity. Based on our results, we propose sp. nov., with the type strain ArsBeeUS (CECT 30499=DSM113403=LMG 32504).