Abstract
Xi.phi.ne.ma.to.bac'ter. Gr. neut. n.
Xiphinema, ‐atos
the genus name of the host organism; N.L. masc. n.
bacter
the equivalent of Gr. neut. n.
baktron
a rod; N.L. masc. n.
Xiphinematobacter
the rod‐shaped microbe associated with
Xiphinema
.
Full‐grown cells are
rod‐shaped with rounded ends, 0.7–1.0 × 2.1–3.2 μm
; however, cells in the J
1
(first juvenile) stage of nematode development have a wrinkled, pleomorphic shape. The longer entities usually consist of a mother cell from which a daughter cell is budding, giving rise to serial pairs typical of this bacterial genus. In thin sections
cells have two or three membranes
consisting of, from inside to outside, a cytoplasmic membrane, an electron‐dense outer membrane, and, in many individuals, a vacuolar membrane which is probably derived from the host cell membrane and which often shows discontinuities.
No peptidoglycan layer is evident
; however, a periplasmic hexagonally arrayed monolayer of 10 nm protein units is sometimes present.
Gram‐stain‐negative, nonmotile, and nonsporulating. DNA is often condensed at cell poles
. Bacteria live as
obligate cytoplasmic symbionts with maternal transmission in nematodes of the
Xiphinema americanum
group
(
Nematoda, Longidoridae
),
in which they are presumed to induce thelytokous
(
mother‐to‐daughter
)
parthenogenesis
.
DNA G
+
C content
(
mol
%): not determined.
Type species
: “
Candidatus
Xiphinematobacter brevicolli
” Vandekerckhove, Willems, Gillis and Coomans 2000, 2203.
Taxonomic and Nomenclature Notes
According to the List of Prokaryotic names with Standing in Nomenclature (LPSN), the taxonomic status of the genus
Candidatus Xiphinematobacter
is: preferred name (not correct name) (last update, February 2025)
*
.
LPSN classification:
Bacteria
/
Pseudomonadati
/
Verrucomicrobiota
/
Terrimicrobiia
/
Terrimicrobiales
/
Chthoniobacteraceae
/
Candidatus Xiphinematobacter
Candidatus Xiphinematobacter
could not be recovered in GTDB
**
.
*
Meier‐Kolthoff
et al. (
2022
).
Nucleic Acids Res
,
50
,
D801
–
D807
; DOI:
10.1093/nar/gkab902
**
Parks
et al. (
2022
).
Nucleic Acids Res
,
50
,
D785
–
D794
; DOI:
10.1093/nar/gkab776