New Species
Table 1 lists a number of new species proposed in several families
since 2000. All of these species have been isolated from clinical
material, and a number have been implicated in infectious disease
processes in the original publication but have not as yet been confirmed
as pathogenic by an independent study or case report.
Several of these taxa bear mentioning. Klebsiella variicola was originally
described in 2004 and appears to be a fairly common clinical
isolate that can cause septicemia and can be misidentified by
automated systems (12,13). Similarly, Escherichia albertii has been
linked to gastrointestinal disease, typically caused by Shiga toxinproducing
Escherichia coli, and has also been reported to have
caused two outbreaks of gastroenteritis in Japan (14,15). Aeromonas
aquariorum has had a checkered history since its original proposal
in 2008. While some studies suggest it is a common clinical
pathogen, it is presently unclear whether it represents a separate
species or belongs to a previously recognized subspecies or biogroup
(Table 2). More taxonomic investigations are needed to resolve these
issues.