Stenotrophomonas, a New Bacterial Genus for Xanthomonas maltophilia (Hugh 1980) Swings et al. 1983

Abstract

Characteristics of the genus Xknthomonas. Following a suggestion by Burkholder (2), Dowson (4) created the name Xanthomonas for a well-defined subgroup of yellow-pigmented phytopathogenic pseudomonads which had been placed together with many other unrelated bacteria in the genus Phytomonas. Dowson (4) defined Xanthomonas as follows: "non-sporing, rod-shaped bacteria. Gram-negative, motile by one polar flagellum (rarely 2 present), or nonmotile, yellow in the mass on nutrient agar and on sterile potato, on both of which abundant slimy growths are formed. Most species digest starch and produce acid in lactose; none produces acid in salicin. " Two corrections were made later by Dowson: deletion of nonmotility and a change from nutrient agar to nutrient glucose agar (5).In subsequent definitions of the genus, the following characteristics were added: absence of poly-P-hydroxybutyrate inclusions, production of highly characteristic brominated aryl-polyene yellow pigments (xanthomonadins), infrequent production of a diffusible, brown color in beef extract agar, digestion of proteins, production of hydrogen sulfide, inability to use asparagine as the sole source of carbon and nitrogen, absence of denitrification and of nitrate reduction, negative or weak oxidase reaction, inhibition of growth by 0.1% (and frequently by 0.02%) triphenyltetrazolium chloride, requirement for growth factors (usually methionine, glutamic acid, nicotinic acid, or a combination of these), optimal growth temperature of 25 to 27"C, DNA base composition (63 to 71 mol% G+C), and plant pathogenicity. Thus far, presence of pili has not been reported for any of the species (1). The slimes produced by various * Corresponding author. species and pathovars were identified as anionic exopolysaccharides, to which the common name "xanthan gums" has been applied. These compounds have very interesting properties and may play a role in the interactions of the pathogens with their respective plant hosts (17). As pointed out by Dye (6), these organisms "form a well-defined remarkably uniform group from which other yellow-pigmented, Gramnegative, monotrichous, aerobic, non-sporing organisms can be distinguished in the laboratory without difficulty."In Bergey's Manual of Systematic Bacteriology (l), five well-characterized species (X. campestris, X. fragariae, X. albilineans, X. axonopodis, and X. ampelina) are described; one of these, X. campestris, is subdivided into many pathovars that are named according to the host plant of origin. The five species accepted by Bradbury (I) were those already included in the 8th edition of Beeey ' s Manual of Determinative Bacteriology (8), but a sixth species of doubtful affiliation (X. populi) was added. For the list of pathovars, Bradbury accepted the one given by Dye et al. (7) and added only two.A review of the genus Xanthomonas was included in the first edition of the treatise The Prokalyotes: a Handbook on Habitats, Isolation and Identification of Bacteria (26). Unfortunately, aside from a summary of the general prope...

Stenotrophomonas rhizophila sp. nov., a novel plant-associated bacterium with antifungal properties.

“…The variety of isolation sources has attracted scientific investigations concerning the epidemiology and differentiation of the strains. A certain heterogeneity in the physiological parameters has already been shown by Swings et al (1983), Van den Mooter & Swings (1990) and also by Palleroni & Bradbury (1993) in the type description of S. maltophilia. Heterogeneity has been confirmed by genotypic studies (Gerner-Smidt et al, 1995 ;Chatelut et al, 1995 ;Nesme et al, 1995 ;Hauben et al, 1999 ;Berg et al, 1999).…”

“…The Stenotrophomonas genus was described with the species Stenotrophomonas maltophilia (Palleroni & Bradbury, 1993), previously called Pseudomonas maltophilia (Hugh & Ryschenko, 1961) and later changed to Xanthomonas maltophilia . Recently, Drancourt et al (1997) proposed a new species ; Stenotrophomonas africana, which is biochemically identical to S. maltophilia except for its …”

The Phylogeny of the Genera Chryseomonas, Flavimonas, and Pseudomonas Supports Synonymy of These Three Genera

“…There was a good correlation between rRNA groups I to V and groups 1 to 5 based on cellular fatty acids and quinone systems. In the past two decades Pseudomonas species belonging to rRNA groups I1 to V or fatty acid and quinone groups 2 to 9 have been transferred to other genera (10,13,14,16,17,19,20). At this time, the genus Pseudomonas is restricted to Palleroni rRNA group I, and only the group I strains belong to the genus Pseudomonas sensu stricto.…”

Pseudomonas gessardii sp. nov. and Pseudomonas migulae sp. nov., two new species isolated from natural mineral waters

“…This has resulted in the drastic restriction of authentic Pseudomonas species to rRNA group I organisms, because it contains the type species, Pseudomonas aeruginosa. Rearrangement of the genus Pseudomonas has entailed the creation of several new genera, while other species have been reassigned to pre-existing genera, such as Chryseomonas and Flavimonas (Holmes et al, 1987), Burkholderia (Yabuuchi et al, 1992), Ralstonia (Yabuuchi et al, 1995), Comamonas (De Vos et al, 1985), Acidovorax (Willems et al, 1990), Hydrogenophaga (Willems et al, 1989), Telluria (Bowman et al, 1993), Stenotrophomonas (Palleroni & Bradbury, 1993), Brevundimonas (Segers et al, 1994), Aminobacter (Urakami et al, 1992), Oligotropha (Meyer et al, 1993), Zavarzinia (Meyer et al, 1993), Sphingomonas (Yabuuchi et al, 1990), Herbaspirillurn (Baldani et al, 1996) and Devosia (Nakagawa et al, 1996). Nowadays, taxonomy is more and more defined as a system 'that should reflect as closely as possible natural relationships between bacteria, by using chronometer molecules such as RNA 16s' (Vandamme et al, 1996).…”