Order of bacteria
The Xanthomonadales are a bacterial order within the
Gammaproteobacteria . They are one of the largest groups of bacterial
phytopathogens , harbouring species such as
Xanthomonas citri ,
Xanthomonas euvesicatoria ,
Xanthomonas oryzae and
Xylella fastidiosa .
[1]
[2]
[3]
[4]
[5] These bacteria affect agriculturally important plants including tomatoes, bananas, citrus plants, rice, and coffee. Many species within the order are also human pathogens. Species within the genus
Stenotrophomonas are
multidrug resistant
opportunistic
pathogens that are responsible for
nosocomial infections in
immunodeficient patients.
[6]
[7]
Characteristics
The Xanthomonadales are
gram-negative ,
catalase positive, non-
spore forming obligate
aerobes .
[8] Members belonging to the order are straight
rods lacking
prosthecae . While some members are non-motile, other species within the order are motile by means of
flagella .
Stenotrophomonas is the only genus capable of
nitrate reduction within the Xanthomonadales.
Taxonomy
The Xanthomonadales consist of 28 validly named genera among two families:
Xanthomonadaceae and
Rhodanobacteraceae .
[9]
[10]
[11] The
Xanthomonadaceae consists of 13 genera while the
Rhodanobacteraceae consist of 14 genera. The families can be distinguished from one another on the basis of
conserved signature indels found among a variety of proteins, specific for each family.
[10] These indels are in parallel with phylogenomic analysis that reveal two distinct clades that appear to be evolutionarily divergent.
Lysobacterales and Lysobacteraceae are earlier synonyms of Xanthomonadales and
Xanthomonadaceae , respectively.
[10]
[12]
Phylogenetic position
The Xanthomonadales are early divergents of bacteria within the
Gammaproteobacteria , and are often used to root phylogenetic trees created for the class.
[13] Until recently, the Xanthomonodales order was inclusive of the families
Xanthomonadaceae ,
Algiphilaceae ,
Solimonadaceae ,
Nevskiaceae and
Sinobacteraceae . However, no
molecular signatures were found that were inclusive of all families.
[10] The organisms were taxonomically rearranged such that Xanthomonadales included
Xanthomonadaceae , which was later divided into two families. The division was in accordance with
CSIs that were found specifically for all members of the emended Xanthomonadales order, providing support for the currently accepted taxonomy. All other species were transferred to
Nevskiales , which did not share CSIs with Xanthomonadales, but remain close relatives within the
Gammaproteobacteria .
[10]
Cardiobacteriales ,
Chromatiales ,
Methylococcales ,
Legionellales and
Thiotrichales are also deep branching orders that are phylogenetic neighbours of Xanthomonadales and
Nevskiales members.
[10]
[13] The order
Nevskiales harbors a single family (
Salinisphaeraceae ) and six genera:
Alkanibacter ,
Fontimonas ,
Hydrocarboniphaga ,
Nevskia ,
Solimonas and
Steroidobacter .
[10]
Wohlfahrtiimonas chitiniclastica and
Ignatzschineria larvae are two species that have historically been accepted as members of the family
Xanthomonadaceae . However, they do not share
conserved signatures with the family, or with the Xanthomonodales order.
[10] These species form deep branching within neighbouring
Gammaproteobacteria , and are monophyletic with
Cardiobacteriales members. These species are thus currently labelled as
incertae sedis .
Phylogeny
The currently accepted taxonomy is based on the
National Center for Biotechnology Information (NCBI).
[9]
References
^ da Silva AC, Ferro JA, Reinach FC, et al. (2002). "Comparison of the genomes of two Xanthomonas pathogens with differing host specificities". Nature . 417 (6887): 459–463.
Bibcode :
2002Natur.417..459D .
doi :
10.1038/417459a .
PMID
12024217 .
S2CID
4302762 .
^ Van Sluys MA, de Oliveira MC, Monteiro-Vitorello CB, et al. (2003).
"Comparative analyses of the complete genome sequences of Pierce's disease and citrus variegated chlorosis strains of Xylella fastidiosa" . J Bacteriol . 185 (3): 1018–26.
doi :
10.1128/JB.185.3.1018-1026.2003 .
PMC
142809 .
PMID
12533478 .
^ Lee BM, Park YJ, Park DS, et al. (2005).
"The genome sequence of Xanthomonas oryzae pathovar oryzae KACC10331, the bacterial blight pathogen of rice" . Nucleic Acids Res . 33 (2): 577–586.
doi :
10.1093/nar/gki206 .
PMC
548351 .
PMID
15673718 .
^ Ryan RP, Vorholter F, Potnis N, et al. (2005). "Pathogenomics of Xanthomonas: understanding bacterium–plant interactions". Nat Rev Microbiol . 9 (5): 344–355.
doi :
10.1038/nrmicro2558 .
PMID
21478901 .
S2CID
37510468 .
^ Chen J, Xie G, Han S, Chertkov O, Sims D, Civerolo EL (2010).
"Whole genome sequences of two Xylella fastidiosa strains (M12 and M23) causing almond leaf scorch disease in California" . J Bacteriol . 192 (17): 4534.
doi :
10.1128/JB.00651-10 .
PMC
2937377 .
PMID
20601474 .
^ Crossman LC, Gould VC, Dow JM, et al. (2008).
"The complete genome, comparative and functional analysis of Stenotrophomonas maltophilia reveals an organism heavily shielded by drug resistance determinants" . Genome Biol . 9 (4): R74.
doi :
10.1186/gb-2008-9-4-r74 .
PMC
2643945 .
PMID
18419807 .
^ Looney WJ, Narita M, Mühlemann K (2009). "Stenotrophomonas maltophilia: an emerging opportunist human pathogen". Lancet Infect Dis . 9 (5): 312–323.
doi :
10.1016/S1473-3099(09)70083-0 .
PMID
19393961 .
^ Saddler GS, Bradbury JF (2005) Order III. Xanthomonadales ord. nov. In: Bergey’s Manual of Systematic Bacteriology. pp. 63-122. Eds Brenner DJ, Krieg NR, Staley JT, Garrity GM, Boone, Vos P, Goodfellow M, Rainey FA, Schleifer K-H Springer-: Austin.
^
a
b Sayers; et al.
"Xanthomonadales" .
National Center for Biotechnology Information (NCBI) taxonomy database. Retrieved 2016-10-24 .
^
a
b
c
d
e
f
g
h Naushad S, Adeolu M, Wong S, Sohail M, Schellhorn HE, Gupta RS (2015). "A phylogenomic and molecular marker based taxonomic framework for the order Xanthomonadales: proposal to transfer the families Algiphilaceae and Solimonadaceae to the order Nevskiales ord. nov. and to create a new family within the order Xanthomonadales, the family Rhodanobacteraceae fam. nov., containing the genus Rhodanobacter and its closest relatives". Antonie van Leeuwenhoek . 107 (2): 467–485.
doi :
10.1007/s10482-014-0344-8 .
PMID
25481407 .
^ Oren A, Garrity GM (2015). "List of new names and new combinations previously effectively, but not validly, published". Int J Syst Evol Microbiol . 65 (7): 2017–2025.
doi :
10.1099/ijs.0.000317 .
^ Christensen P, Cook F (1978).
"Lysobacter, a New Genus of Nonfruiting, Gliding Bacteria with a High Base Ratio" . Int J Syst Evol Microbiol . 28 (3): 367–393.
doi :
10.1099/00207713-28-3-367 .
^
a
b Cutiño-Jiménez AM, Martins-Pinheiro M, Lima WC, Martín-Tornet A, Morales OG, Menck CF (2010).
"Evolutionary placement of Xanthomonadales based on conserved protein signature sequences" . Mol Phylogenet Evol . 54 (2): 524–34.
doi :
10.1016/j.ympev.2009.09.026 .
PMID
19786109 .
Terrabacteria
BV1, BV3, BV5
others Cyanoprokaryota
Cyanobacteriota
"
Margulisiibacteriota "
"Marinamargulisbacteria"
"Riflemargulisbacteria"
"Saganbacteria"
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Firmicutes
BV3 Low GC
Bacillota
Bacillota A
"
Clostridiia "
"Thermoanaerobacteria"
"Thermosediminibacteria"
Bacillota D
Bacillota E
"Sulfobacillia"
"Symbiobacteriia"
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Bacillota G
"Hydrogenisporia"
Limnochordia
"
Desulfotomaculota "
"Carboxydocellia"
"Carboxydothermia"
"Dehalobacteriia"
"Desulfitobacteriia"
"Desulfotomaculia"
"Moorellia"
"Peptococcia"
"Syntrophomonadia"
"Thermincolia"
"Halanaerobiaeota"
"Selenobacteria"
CPR group Thermotogida
Fusobacterida
Hydrobacteria
BV2, BV4
others