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A Gram-stain-negative, non-motile, non-sporulating, rod-shaped, orange-pigmented bacterium, designated strain FQM01T, was isolated from a subterranean sediment sample in the Mohe permafrost area, China. Strain FQM01T grew optimally at 25 °C, pH 7.0 and NaCl concentration of 0 % (w/v). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain FQM01T belonged to the genus Sphingomonas . The closest phylogenetic relative was Sphingomonas spermidinifaciens GDMCC 1.657T (97.6 %), followed by Sphingomonas mucosissima DSM 17494T (97.2 %). The DNA G+C content of the isolate was 66.9 mol%. Strain FQM01T contained Q-10 as the predominant ubiquinone, and C18 : 1ω6c and/or C18 : 1ω7c, C16 : 1ω6c and/or C16 : 1ω7c, C16 : 0, C14 : 0 2-OH and C18 : 1 ω7c 11 methyl as the major fatty acids. Major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid and an unidentified glycolipid. Only sym-homospermidine was detected as the polyamine. On the basis of phylogenetic and phenotypic data, strain FQM01T is considered to represent a novel species of Sphingomonas for which the name Sphingomonas floccifaciens sp. nov. is proposed. The type strain is FQM01T (=CGMCC 1.15797T=KCTC 52630T).

A novel Sphingomonas strain was isolated from a sample of desert soil collected near Jeddah in Saudi Arabia. A polyphasic approach was performed to characterize this strain, initially designated as G39T. Cells of strain G39T are motile, Gram-negative, catalase- and oxidase-positive. The strain is able to grow aerobically at 20-35 °C, pH 6.5-8 and tolerates up to 4 % (w/v) NaCl. Based on 16S rRNA gene sequence similarity, the closest relative type strains of G39T are Sphingomonas mucosissima DSM 17494T (98.6 %), S. dokdonensis DSM 21029T (98.4 %) and S. hankookensis DSM 23329T (97.4 %). Furthermore, the average nucleotide identities between the draft genome sequence of strain G39T and the genome sequences of all other available and related Sphingomonas species are significantly below the threshold of 94 %. The G+C content of the draft genome (3.12 Mbp) is 65.84 %. The prevalent (>5 %) cellular fatty acids of G39T were C18 : 1ω7c, C16 : 1ω7c and/or C16 : 1ω6c, C14 : 0 2-OH and C16 : 0. The only detectable respiratory quinone was ubiquinone-10 and the polar lipids profile is composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, as well as unidentified lipids, phospholipids and glycolipids. The results of the conducted polyphasic approach confirmed that this isolate represents a novel species of the genus Sphingomonas, for which the name Sphingomonas jeddahensis sp. nov. is proposed. The type strain of this species is G39T (=DSM 103790T=LMG 29955T). peerReviewed

Sphingomonas mucosissima and Sphingomonas dokdonensis are Gram-negative chemoheterotrophic strictly aerobic rods or cocci. The genomes (3.453 Mb and 3.587 Mb, respectively) contain 3,279 and 3,329 predicted protein-encoding genes, respectively. The genome of S. dokdonensis harbors a 90-kb plasmid.

Water delivered through dental unit waterline system (DUWS) is often reported contaminated with microbes dislodged from biofilm that forms within the tubing of a dental chair unit (DCU). ADM: The study aimed at evaluating the sanitary level of DCU water from a teaching dental clinic. Materials: The presence of pathogenic bacteria which include total coliforms, faecal coliforms, E. coli, faecal streptococci and P. aeruginosa were determined using conventional microbiological methods while PCR technique was used to identify other microbial contaminants. Result: pH of DCU water was found slightly acidic at pH 5.4-5.5 and the temperature was 23°C. Pathogenic contaminants were absent but the DCU water was highly loaded with Sphingomonas rhizogenes (17.9%), Sphingomonas dokdonesis (79.5%), Sphingomonas mucosissima (1.1%) and Methylobacterium radiotolerans (1.5%). The high load of microbes that exceeded 200 cfu/ml was of great concern as it failed to meet recommendation set by the American Dental Association.

Two bacterial strains, CP173-2Tand CP1DT, were isolated from biological soil crusts (BSCs) collected in the Colorado Plateau, USA. Both strains were pigmented, Gram-negative, non-motile rods and produced abundant mucus. They contained C16 : 0, C18 : 1ω7cand C14 : 02-OH as the predominant cellular fatty acids, ubiquinone-10 as the isoprenoid quinone and sphingoglycolipid. Based on the above characteristics, the isolates were assigned to the familySphingomonadaceae; 16 rRNA gene signature nucleotides placed them within the genusSphingomonas. Strains CP173-2Tand CP1DThad a 16S rRNA gene sequence similarity of 96.7 % with each other and 91.6–98.9 % sequence similarity with other species in the genus, indicating that they represent two separate, and possibly novel, species. The closest species to strains CP173-2Tand CP1DTwere, respectively,Sphingomonas dokdonensis(98.9 % gene sequence similarity) andSphingomonas panni(97.9 %). However, strain CP173-2Texhibited a DNA–DNA relatedness of only 32.5 % with the type strain ofS. dokdonensis. Similarly, the DNA–DNA relatedness between strain CP1DTand the type strain ofS. panniwas only 18 %. Phenotypic characterization supported this low relatedness. On the basis of this evidence, we propose that the new strains represent two novel species, for which the namesSphingomonas mucosissimasp. nov. (with type strain CP173-2T=ATCC BAA-1239T=DSM 17494T) andSphingomonas desiccabilissp. nov. (with type strain CP1DT=ATCC BAA-1041T=DSM 16792T) are proposed.

Strain DCY91(T), a Gram-stain-negative, rod-shaped, aerobic, non-motile bacterium, was isolated from soil of ginseng field in Gyeonggi province, South Korea. Strain DCY91(T) shared the highest 16S rRNA gene sequence similarity with Sphingomonas mucosissima DSM 17494(T) (98.55%), Sphingomonas dokdonensis KACC 17420(T) (98.11%) and Sphingomonas xinjiangensis DSM 26736(T) (96.68%). The strain DCY91(T) was found to able to grow best in trypticase soy agar at 28 °C, at pH 7 and at 0.5 % NaCl. Ubiquinone 10 was identified as the isoprenoid quinone. The major polar lipids were identified as sphingoglycolipid, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine. The major fatty acids of strain DCY91(T) were identified as unsaturated C18:1 ω7c and saturated C16:0. The major polyamine content was sym-homospermidine. The DNA G + C content was determined to be 65.8 mol% (HPLC). After 6 days of incubation, strain DCY91(T) produced 9.64 ± 1.73 and 33.73 ± 4.66 µg/ml indole-3-acetic acid, using media without L-tryptophan and supplemented with L-tryptophan, respectively. Strain DCY91(T) was also weakly solubilized phosphate and produced siderophores. On the basis of the phenotypic characteristics, genotypic analysis and chemotaxonomic characteristics, strain DCY91(T) is considered to represent a novel species of the genus Sphingomonas, for which the name Sphingomonas panaciterrae sp. nov. is proposed. The type strain is DCY91(T) (=KCTC 42346(T) =JCM 30807(T)).

To the Editor: The genus Sphingomonas was proposed by Yabuuchi et al. in 1990 (1) and amended by Takeuchi et al. in 1993 (2). It now has been subdivided into 4 separate genera: Sphingomonas sensu stricto, Sphingobium, Novosphingobium, and Sphingopyxis. The bacteria of the genus Sphingomonas are yellow-pigmented, nonfermenting, gram-negative bacilli with a single polar flagellum; they are widely distributed in the natural environment, especially in water and soil (3). These bacteria are characterized by the presence of a unique sphingoglycolipid with the long-chain base—dihydrosphingosin, ubiquinone 10 (Q-10), and 2-hydroxymyristic acid (2-OH C14:0)—and the absence of 3-hydroxy fatty acids (4). S. mucosissima was isolated and identified in 2007 by Reddy and Garcia-Pichel from biologic soil crust samples collected from sandy arid soil in the US Colorado Plateau (5). Sphingomonas spp. are opportunistic pathogens and have recently been implicated in a variety of community-acquired and nosocomial infections, considered to originate from contaminated hospital equipment or manipulation of some medical devices (3). The survival of Sphingomonas spp. in indoor dust particles as aerosols and their resistance to many disinfecting and toxic chemicals may explain their ability to colonize medical devices such as mechanical ventilators, catheters, and bronchofiberoscopes (6). In the past few years, these organisms, in particular S. paucimobilis, have been implicated in a variety of community-acquired and nosocomial infections. We report a case of S. mucosissima bacteremia in a patient with sickle cell disease. In February 2008, a 17-year-old woman with homozygous sickle cell anemia was hospitalized when her condition suddenly became worse. The patient had undergone a splenectomy in 1992 and a cholecystectomy in February 2007. Four days after admission, she had a fever of 38.7°C. Two aerobic blood specimens, drawn on the fifth day of her hospitalization, yielded gram-negative bacilli after a 24-hour incubation. The gram-negative bacilli were positive for catalase and oxidase but remained unidentified by API 20NE strip (bioMerieux, Marcy l’Etoile, France). MICs of antimicrobial drugs were determined for the gram-negative bacilli by using an Etest assay (AB BIODISK, Solna, Sweden) on Mueller-Hinton medium. MICs were 1 μg/mL for cefotaxime, 1 μg/mL for amoxicillin–clavulanic acid, 2–3 μg/mL for vancomycin, 0.064 μg/mL for imipenem, 4–5 μg/mL for ceftazidime, 1 μg/mL for amikacin, 3 μg/mL for ciprofloxacin, and 0.047 μg/mL for trimethoprim-sulfamethoxazole. DNA was extracted from 1 colony by using a QIAamp Tissue kit (QIAGEN, Hilden, Germany) as described by the manufacturer. A 16S rDNA sequence was obtained (1,410 bp) by using the fD1 (5′-AGAGTTTGATCCTGGCTCAG-3′) and rP2 (5′-ACGGCTACCTTGTTACGACTT-3′) primer pair (7,8). Using BLAST version 2.2.9 software (www.ncbi.nlm.nig.gov/BLAST), we determined that this sequence showed 98% similarity with the 16S rDNA sequence of S. mucosissima (GenBank accession no. {"type":"entrez-nucleotide","attrs":{"text":"AM229669","term_id":"87080454","term_text":"AM229669"}}AM229669). A phylogenetic neighbor-joining tree resulting from comparison of sequences of the 16S rDNA genes of Sphingomonas spp. was made with the MEGA 3.1 software (www.megasoftware.net). This analysis confirmed that the isolate belonged to S. mucosissima. Initial treatment of intravenous administration of ceftriaxone was begun. The fever resolved after 1 day and the patient’s condition improved. Treatment was stopped after 5 days, and the patient remained apyretic. Two S. mucosissima isolates were recovered from 2 different blood-culture samples drawn 24 hours apart, which suggests that S. mucosissima was not just a transient organism but indeed was responsible for the patient’s septicemia. Phenotypic identification of the gram-negative bacilli failed because the definite bacterial species S. mucosissima was not included in the API database (http://industry.biomerieux-usa.com/industry/food/api/apiweb.htm) used for the phenotypic identification. However, the isolates’ biochemical characteristics were consistent with those previously reported for S. mucosissima (5) (Table). Final identification was achieved by comparing the almost complete 16S rDNA sequence with homologous sequences deposited in GenBank. Table Biochemical characteristics of the previously reported Sphingomonas mucosissima isolate ({"type":"entrez-nucleotide","attrs":{"text":"AM229669","term_id":"87080454","term_text":"AM229669"}}AM229669) and the isolate from this study We believe that the patient’s intravenous catheter was the source of the infection because she did not have wound infections and cultures of her urine were negative for infectious agents. Antimicrobial drug treatment, selected on the basis of an in vitro S. mucosissima susceptibility profile, facilitated the patient’s recovery. This case report illustrates that the pathogenic potential of S. mucosissima should be considered in diagnosis in such cases because the organism can cause bacteremia in patients, primarily in those with underlying debilitating conditions and those who have undergone medical interventions.