During
the
course
of
his
work,
however,
he
became
infected
and
fell
victim.
to
the
disease.
The
name
rickettsiae
was
coined
to
honour
the
discoverer.
Originally,
these
again
were
set
apmt
from
bacteria,
but
in
the
most
recent
edition
of
Bergey's
Manual
(1974),
they
have
been
included
as
Part
18
in
Division
II,
the
Bacteria.
The
fundamental
differences
from
ordinary
bacteria
are
(i)
a
smaller
size
with
smaller
genome
providing
fewer
enzymes
(ii)
a
longer
generation
time
and
(Hi)
a
requirement
for
an
exogenous
energy
supply
for
growth.
They
infect
ordinarily
non
phagocytic
cells
and
are
protected
from
lysosomal
degradation
by
envelopment
in
a
vesicle
of
the
host
cell
membrane.
| 
