Biotechnological potential of psychrotolerant methylobacteria isolated from biotopes of Antarctic oases.

Ten strains of psychrotolerant methylotrophic bacteria were isolated from the samples collected in Larsemann and Bunger Hills (Antarctica). Most of the isolates are assigned to the genus Pseudomonas, representatives of the genera Janthinobacterium, Massilia, Methylotenera and Flavobacterium were also found. Majority of isolates were able to grow on a wide range of sugars, methylamines and other substrates. Optimal growth temperatures for the isolated strains varied from 6 °C to 28 °C. The optimal concentration of NaCl was 0.5-2.0%. The optimal pH values of the medium were 6-7. It was found that three strains synthesized indole-3-acetic acid on a medium with L-tryptophan reaching 11-12 µg/ml. The values of intracellular carbohydrates in several strains exceeded 50 µg/ml. Presence of calcium-dependent and lanthanum-dependent methanol dehydrogenase have been shown for some isolates. Strains xBan7, xBan20, xBan37, xBan49, xPrg27, xPrg48, xPrg51 showed the presence of free amino acids. Bioprospection of Earth cryosphere for such microorganisms has a potential in biotechnology.

Roseateles caseinilyticus sp. nov. and Roseateles cellulosilyticus sp. nov., isolated from rice paddy field soil.

Two novel Gram-stain-negative strains designated P7T and P8T, were isolated from the soil of a paddy field in Goyang, Republic of Korea, and identified as new species within the genus Roseateles through a polyphasic taxonomic approach. These aerobic, rod-shaped, non-sporulating strains demonstrated optimal growth at 30 °C, pH 7, and in the absence of NaCl (0% w/v). Phylogenetic analysis based on 16S rRNA gene sequences indicated close relationships with Roseateles saccharophilus DSM654T (98.7%) and Roseateles puraquae CCUG 52769T (98.96%), respectively. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the isolates with the most closely related strains with publicly available whole genomes were 82.0-85.5% and 25.0-30.2%, respectively. The predominant fatty acids identified were C16:0 and summed feature 3 (composed of C16:1 ω6c and/or C16:1 ω7c), with minor amounts of C12:0, C10:0 3-OH and summed feature 8 (composed of C18:1 ω7c and/or C18:1 ω6c; 26.4%). Ubiquinone 8 was the main quinone, and the polar lipid profile included phosphatidylethanolamine, phosphatidylglycerol, two unidentified phosphoaminolipids, one unidentified phosphoglycolipid, three unidentified phospholipids, and one unidentified aminolipid. The draft genome sequences revealed genomic DNA G + C contents of 70.1% for P7T and 68.2% for P8T. Comprehensive physiological, biochemical, and 16S rRNA sequence analyses confirm these isolates as novel species of the genus Roseateles, proposed to be named Roseateles caseinilyticus sp. nov for strain P7T (= KACC 22504T = TBRC 15694T) and Roseateles cellulosilyticus sp. nov. for strain P8T (= KACC 22505T = TBRC 15695T).

Roseomonas populi sp. nov., an acetate-degrading bacteria isolated from the stem of Populus tomentosa.

Strain CN29T, isolated from the stem of 5- to 6-year-old Populus tomentosa in Shandong, China, was characterized using a polyphasic taxonomic approach. Cells of CN29T were Gram-stain negative, aerobic, nonspore-forming, and nonmotile coccoid. Growth occurred at 20-37 °C, pH 4.0-9.0 (optimum, pH 6.0), and with 0-1% NaCl (optimum, 1%). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain CN29T was closely related to members of the genus Roseomonas and closest to Roseomonas pecuniae N75T (96.6%). This classification was further supported by phylogenetic analysis using additional core genes. The average nucleotide identity and digital DNA‒DNA hybridization values between strain CN29T and Roseomonas populi CN29T were 82.7% and 27.8%, respectively. The genome size of strain CN29T was 5.87 Mb, with a G + C content of 70.9%. The major cellular fatty acids included summed feature 8 (C18:1 ω7c/C18:1 ω6c), C19:0 cyclo ω8c and C16:0. The major respiratory quinone was Q-10. The polar lipids were phosphatidylcholine, aminolipid, phosphatidylglycerol, and diphosphatidylglycerol. Strain CN29T can utilize acetate as a carbon source for growth and metabolism. Additionally, it contains acid phosphatase (2-naphthyl phosphate), which catalyzes the hydrolysis of phosphoric monoesters. The CN29T strain contains several genes, including maeB, gdhB, and cysJ, involved in carbon, nitrogen, and sulfur cycling. These findings suggest that the strain may actively participate in ecosystem cycling, leading to soil improvement and promoting the growth of poplar trees. Based on the phylogenetic, phenotypic, and genotypic characteristics, strain CN29T is concluded to represent a novel species of the genus Roseomonas, for which the name Roseomonas populi sp. nov. is proposed. The type strain is CN29T (= JCM 35579T = GDMCC 1.3267T).

Roseomonas rubea sp. nov., isolated from rice paddy soil.

Three pale-red-pigmented, Gram-stain-negative, coccobacilli-shaped, motile and strictly aerobic bacteria, strains MO17T, MO41 and NPKOSM1, were isolated from rice paddy soil. Colonies were circular with entire edges, convex and pale red. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains MO17T, MO41 and NPKOSM1 belonged to the genus Roseomonas and were closely related to Roseomonas sediminicola FW-3T (98.2 %), Roseomonas oryzicola YC6724T (98.0 %), Roseomonas soli 5N26T (98.0 %), Roseomonas eburnea BUT-5T (97.8 %), Roseomonas alkaliterrae YIM 78007T (97.7 %), Roseomonas lacus TH-G33T (97.6 %) and Roseomonas terrae DS-48T (96.8 %). The DNA-DNA hybridization values between strains MO17T, MO41 and NPKOSM1 were 84-92 %, and the values between the three strains and their close phylogenetic relatives were also below 70 %. The major cellular fatty acids were C18 : 1 ω7c, C16 : 0 and summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2OH). The predominant respiratory quinone was identified as Q-10. The polar lipids detected were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, one unidentified aminophospholipid and two unknown phospholipids. Based on their distinctive phenotypic, phylogenetic and chemotaxonomic characteristics, the three strains are considered to represent novel species of the genus Roseomonas for which the name Roseomonas rubea sp. nov. is proposed. The type strain is MO17T (=KACC 19933T=NBRC 114495T).

Isolation and characterization of tick-borne Roseomonas haemaphysalidis sp. nov. and rodent-borne Roseomonas marmotae sp. nov.

Four novel Gram-negative, mesophilic, aerobic, motile, and cocci-shaped strains were isolated from tick samples (strains 546T and 573) and respiratory tracts of marmots (strains 1318T and 1311). The 16S rRNA gene sequencing revealed that strains 546T and 573 were 97.8% identical to Roseomonas wenyumeiae Z23T, whereas strains 1311 and 1318T were 98.3% identical to Roseomonas ludipueritiae DSM 14915T. In addition, a 98.0% identity was observed between strains 546T and 1318T. Phylogenetic and phylogenomic analyses revealed that strains 546T and 573 clustered with R. wenyumeiae Z23T, whereas strains 1311 and 1318T grouped with R. ludipueritiae DSM 14915T. The average nucleotide identity between our isolates and members of the genus Roseomonas was below 95%. The genomic G+C content of strains 546T and 1318T was 70.9% and 69.3%, respectively. Diphosphatidylglycerol (DPG) and phosphatidylethanolamine (PE) were the major polar lipids, with Q-10 as the predominant respiratory quinone. According to all genotypic, phenotypic, phylogenetic, and phylogenomic analyses, the four strains represent two novel species of the genus Roseomonas, for which the names Roseomonas haemaphysalidis sp. nov. and Roseomonas marmotae sp. nov. are proposed, with 546T (= GDMCC 1.1780T = JCM 34187T) and 1318T (= GDMCC 1.1781T = JCM 34188T) as type strains, respectively.

Roseomonas oleicola sp. nov., isolated from an oil production mixture in Yumen Oilfield, and emended description of Roseomonas frigidaquae.

A pink, ovoid-shaped, Gram-stain-negative, strictly aerobic and motile bacterial strain, designated ROY-5-3T, was isolated from an oil production mixture from Yumen Oilfield in PR China. The strain grew at 4-42 °C (optimum, 30 °C), at pH 5-10 (optimum, 7) and with 0-5 % (w/v) NaCl (optimum, 0%). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that ROY-5-3T belongs to the genus Roseomonas and shared the highest pairwise similarities with Roseomonas frigidaquae CW67T (98.1%), Roseomonas selenitidurans BU-1T (97.8%), Roseomonas tokyonensis K-20T (97.7%) and Roseomonas stagni HS-69T (97.3%). The average nucleotide identity and digital DNA-DNA hybridization values between ROY-5-3T and other related type strains of Roseomonas species were less than 84.08 and 28.60 %, respectively, both below the species delineation threshold. Pan-genomic analysis showed that the novel isolate ROY-5-3T shared 3265 core gene families with the four closely related type strains in Roseomonas, and the number of strain-specific gene families was 513. The major fatty acids were identified as summed feature 8 (C18 : 1 ω6c/C18 : 1 ω7c), summed feature 3 (C16 : 1 ω6c/C16 : 1 ω7c) and C16 : 0. Strain ROY-5-3T contained Q-10 as the main ubiquinone and the genomic DNA G+C content was 69.8 mol%. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol. Based on the phylogenetic, morphological, physiological, chemotaxonomic and genome analyses, strain ROY-5-3T represents a novel species of the genus Roseomonas for which the name Roseomonas oleicola sp. nov. is proposed. The type strain is ROY-5-3T (=CGMCC 1.13459T =KCTC 82484T).

Roseomonas ponticola sp. nov., a novel bacterium isolated from Pearl River estuary.

A novel species of the genus Roseomonas, designated SYSU M41301T, was isolated from water sample of the Pearl River estuary in Guangdong, China. Polyphasic, taxonomic and phylogenomic analyses were used to determine the taxonomy position of the strain. Phylogenetic analysis using 16S rRNA gene sequence indicated that strain SYSU M41301T showed the highest sequence similarity to Roseomonas stagni KCTC 22213T (97.9 %) and Roseomonas riguiloci KCTC 23339T (96.4 %). The novel species could be differentiated from other species of the genus Roseomonas by its distinct phenotypic and genotypic characteristics. The isolate was Gram-staining-negative, aerobic, short rod-shape, oxidase-positive and non-motile. The predominant respiratory quinone was ubiquinone 8 (Q-8). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, and one unidentified polar lipid. The major fatty acids (>10 % of total) were 11-methyl C18 : 1 ω7c, summed feature 3 (C16 : 1 ω7c and/ or C16 : 1 ω6c) and summed feature 8 (C18:  :1 ω7c and/or C18 : 1 ω6c). The G+C content of the novel isolate based on genomic DNA was 72.0 mol%. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU M41301T should be considered to represent a novel species in the genus Roseomonas, for which the name Roseomonas ponticola sp. nov. is proposed with the type strain SYSU M41301T (=KCTC 72726T=CGMCC 1.18613T).

Roseomonas hellenica sp. nov., isolated from roots of wild-growing Alkanna tinctoria.

Two Gram-negative, aerobic, rod-shaped and yellow-orange pigmented bacterial strains (LMG 31523T and LMG 31524) were isolated from roots of wild-growing Alkanna tinctoria plants collected near Thessaloniki, Greece. Analysis of their 16S rRNA gene sequences revealed that they form a separate cluster related to the genus Roseomonas. A comparative whole genome analysis of the two strains and the type strains of related Roseomonas species revealed average nucleotide identity values from 78.84 and 80.32%. The G + C contents of the genomic DNA of strains LMG 31523T and LMG 31524 were 69.69% and 69.74%, respectively. Combined data from phenotypic, phylogenetic and chemotaxonomic studies indicated that the strains LMG 31523T and LMG 31524 represent a novel species of the genus Roseomonas. Genome analysis of the new strains showed a number of genes involved in survival in the rhizosphere environment and in plant colonization and confirmed the endophytic characteristics of LMG 31523T and LMG 31524. Since the strains LMG 31523T and LMG 31524 were isolated from a plant collected in Greece the name Roseomonas hellenica sp. nov. is proposed. The type strain is LMG 31523T (=CECT 30032T).

Roseomonas coralli sp. nov., a heavy metal resistant bacterium isolated from coral.

A Gram-stain-negative, aerobic, mesophilic, non-motile bacterium, designated M0104T, was isolated from a gorgonian coral collected from Xieyang island, Guangxi Province, PR China. Colonies of the strain were non-motile cocci and pink. The strain grew at 15-34 °C (optimum, 28 °C), pH 4.5-8.0 (optimum, pH 7.0) and with 0-4% (w/v) NaCl (optimum, 0-2 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain M0104T was closely related to Roseomonas deserti JCM 31275T (96.2 %), Roseomonas vastitatis KCTC 62043T (96.0 %), Roseomonas aerofrigidensis JCM 31878T (95.9 %) and Roseomonas oryzae KCTC 42542T (95.7 %). The strain had an assembly size of 5.0 Mb and a G+C content of 71.0mol%. Genes involved in copper, cadmium, lead, arsenic and zinc resistance were identified in the genome of strain M0104T. The digital DNA-DNA hybridization and average nucleotide identity values between the genome sequence of strain M0104T and those of closely related type strains were 19.4-24.9 % and 74.3-81.8 %, respectively. Strain M0104T contained C18:1 ω7c, C18:3 ω3c, anteiso C11:0 and C16:0 as the major fatty acids (>7 %) and ubiquinone Q-10 as the sole isoprenoid quinone. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine were its major polar lipids. Based on its phenotypic, phylogenetic and chemotaxonomic properties, strain M0104T is proposed to represent a novel species within the genus Roseomonas, for which the name Roseomonas coralli sp. nov. is proposed. The type strain is M0104T (=KCTC 62359T=MCCC 1K03632T).

Roseomonas selenitidurans sp. nov., isolated from urban soil, and emended description of Roseomonas frigidaquae.

An aerobic, non-motile, Gram-stain-negative, pink, convex, coccobacilli-shaped, mesophilic bacterium, designated strain BU-1T, was isolated from an urban soil sample from Zibo city, Shandong province, PR China. The strain grew at 20-37 °C (optimum, 30 °C), pH 5-10 (optimum, pH 7) and growth occurred with 0-2 % (w/v) NaCl (optimally with 0.5 %). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that BU-1T was closely related to members of the genus Roseomonas and had highest 16S rRNA gene sequence similarities with Roseomonas frigidaquae JCM 15073T (97.8 %), Roseomonas tokyonensis JCM 14634T (96.9 %), Roseomonas stagni JCM 15034T (96.5 %), and Roseomonas riguiloci JCM 17520T (95.9 %). BU-1T also formed a subcluster with R. frigidaquae JCM 15073T and R. stagni JCM 15034T in phylogenetic trees based on genomic sequences. The genome size of BU-1T was 5.79 Mb and the DNA G+C content was 71.7 %. ANI, dDDH and AAI values between BU-1T and R. frigidaquae JCM 15073T were 84.0, 27.2 and 86.7 %, respectively. Furthermore, the genome of BU-1T contained 5446 predicted protein coding genes and 4945 (90.8%) of them had classifiable functions. BU-1T contained Q-10 as the main ubiquinone. The predominant fatty acids (>10 %) were summed feature 3, summed feature 8 and C16:0. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and five unidentified aminolipids. Combined data from phenotypic, phylogenetic and chemotaxonomic studies indicated that strain BU-1T is a representative of a novel species of the genus Roseomonas. Since strain BU-1T can reduce highly toxic selenite [Se(IV)] to low toxicity elemental selenium [Se(0)], the name Roseomonas selenitidurans sp. nov. is proposed. The type strain is BU-1T (=KACC 21750T =GDMCC 1.1776T).

Roseomonas gilardii in patient with leukemia and acute appendicitis: case report and review.

Appendicitis is one of the most common abdominal conditions requiring emergency surgery. However, acute appendicitis in patients with leukemia is a rare condition. We report herein the case of an 18-year-old female with acute lymphoblastic leukemia (ALL), who was hospitalized in hematology department because of abdominal pain and fever. Ultrasound (US) of the abdomen revealed appendicitis and the patients underwent open appendectomy. The patient recovered without complications and was discharged in a good condition. The day of the operation blood and peritoneal fluid cultures were taken and Roseomonas gilardii was detected and healed empirically. The correct diagnosis of appendicitis in patients with leukemia and their management is challenging for physicians. Very rare microorganisms can be detected in these patients.

Roseomonas harenae sp. nov., from desert gravel soil.

A Gram-stain-negative, aerobic, non-motile, pink-pigmented, coccus bacterium, designated CPCC 101081T, was isolated from a gravel soil sample collected from Badain Jara desert, PR China. Growth of the isolate occurred at 10-37 °C and pH 5.0-8.0, with optimal growth at 28-32 °C and pH 7.0, respectively. The major cellular fatty acids were summed feature 8 (C18:1ω7c/C 18:1ω6c), summed feature 3 (C 16:1ω6c/C16:1ω7c) and C18:12-OH. Q-10 was detected as the main respiratory quinone. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified phospholipid, an amino-containing lipid and an unidentified glycophospholipid were examined in the polar lipids extraction. The 16S rRNA gene sequence comparison of strain CPCC 101081T with the available sequences in the GenBank database showed that the isolate was closely related to members of the genus Rosenomonas, with the highest similarity to Roseomonas rosea DSM 14916T (97.4 %). In the phylogenetic trees based on 16S rRNA gene sequences and the core genomes, strain CPCC 101081T was included within the clade of the genus Roseomonas, representing a species level, with the closest neighbor of R. rosea DSM 14916T . The genomic DNA G+C content was 68.7 mol%. The average nucleotide identity and the digital DNA-DNA hybridization values between strain CPCC 101081T and the related type strains of the genus Roseomonas were all far lower than the cut-off values for definition species. On the basis of above phenotypic and genotypic characteristics, strain CPCC 101081T is proposed to represent a novel species of the genus Roseomonas with the name Roseomonas harenae sp. nov. strain CPCC 101081T (=KCTC 62852T=NBRC 113512T) is the type strain of the species.

Roseomonas bella sp. nov., isolated from lake sediment.

A Gram-stain-negative, non-motile, coccus-shaped, catalase- and oxidase-positive, facultatively anaerobic and pink-pigmented bacterium, designated strain CQN31T, was isolated from sediment of Changqiaohai Lake, Yunnan Province, China. Growth occurred at 4-45 °C (optimum, 37 °C), at pH 6.5-9.5 (optimum, pH 8.0) and with 0-1 % (w/v) NaCl (optimum, 0 %). C18 : 1 ω7c/C18 : 1 ω6c and C16 : 0 were the predominant fatty acids. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidyldimethylethanolamine (PME) and one unidentified aminolipid (AL) were the major polar lipids. The G+C content of the genomic DNA was 71.5 %. 16S rRNA gene sequence comparisons indicated that strain CQN31T shared 96.8 % similarity with Roseomonas wooponensis JCM 19527T and 95.9 % with R. terricola EM0302T. Digital DNA-DNA hybridization values between strain CQN31T and Roseomonas stagni DSM 19981T, R. rosea DSM 14916T and R. mucosa NCTC 13291T were 21.0, 19.4 and 19.8 %, respectively. Average amino acid identity and average nucleotide identity values between strain CQN31T and R. stagni DSM 19981T, R. rosea DSM 14916T and R. mucosa NCTC 13291T were 73.7, 63.4 and 61.9 %, and 79.2, 77.1 and 77.5%, respectively. Distinct morphological, physiological and genotypic differences from previously described taxa support the classification of strain CQN31T as a representative of a novel species in the genus Roseomonas, for which the name Roseomonas bella sp. nov. is proposed. The type strain is CQN31T (=KCTC 62447T=MCCC 1H00309T).

Roseomonas species infections in humans: a systematic review.

Roseomonas species have been recognized to cause infections in immunocompromised individuals. The purpose of this study was to systemically review all published cases of Roseomonas infections in humans and describe the epidemiology, microbiology, antimicrobial susceptibility, treatment and outcomes of these infections in humans. We performed a systematic review of PubMed (through 20th Octrober 2019) for studies providing epidemiological, clinical, microbiological as well as treatment data and outcomes of Roseomonas species infections. A total of 37 studies, containing data of 99 patients, were included in the analysis. The most common Roseomonas infections were those of the bloodstream in 74.7% (74 patients), musculoskeletal infections in 8.1% (8 patients), skin and soft tissue infections (SSTIs) and peritoneal dialysis-associated peritonitis in 6.1% (6 patients) each. Epidemiology of these infections differed, with bacteremias being more prevalent in patients with malignancy and central venous lines, musculoskeletal infections being more prevalent after orthopedic surgery, and SSTIs occurring without any reported underlying cause. Resistance to beta-lactams was very high with penicillin, piperacillin/tazobactam resistance and cephalosporin resistance at 96.6%, 90.7% and 77.8% respectively, while quinolone resistance was 9.1%. Quinolones, carbapenems and cephalosporins are the most common agents used for treatment, irrespectively of the infection site. Overall mortality was 3% (3 patients), with the mortality attributed to Roseomonas being at 1% (1 patient).

The Genome Analysis of Methylobacterium populi YC-XJ1 with Diverse Xenobiotics Biodegrading Capacity and Degradation Characteristics of Related Hydrolase.

Methylobacterium populi YC-XJ1 isolated from desert soil exhibited a diverse degrading ability towards aromatic oxyphenoxypropionic acid esters (AOPPs) herbicide, phthalate esters (PAEs), organophosphorus flame retardants (OPFRs), chlorpyrifos and phoxim. The genome of YC-XJ1 was sequenced and analyzed systematically. YC-XJ1 contained a large number of exogenous compounds degradation pathways and hydrolase resources. The quizalofop-p-ethyl (QPE) degrading gene qpeh2 and diethyl phthalate (DEP) degrading gene deph1 were cloned and expressed. The characteristics of corresponding hydrolases were investigated. The specific activity of recombinant QPEH2 was 0.1 ± 0.02 U mg-1 for QPE with kcat/Km values of 1.8 ± 0.016 (mM-1·s-1). The specific activity of recombinant DEPH1 was 0.1 ± 0.02 U mg-1 for DEP with kcat/Km values of 0.8 ± 0.02 (mM-1·s-1). This work systematically illuminated the metabolic versatility of strain YC-XJ1 via the combination of genomics analysis and laboratory experiments. These results suggested that strain YC-XJ1 with diverse xenobiotics biodegrading capacity was a promising candidate for the bioremediation of polluted sites.

Microvirga arsenatis sp. nov., an arsenate reduction bacterium isolated from Tibet hot spring sediments.

Two novel Gram-stain negative, moderately thermophilic, aerobic, rod-shaped strains, designated 3D203T and 3D207, were isolated from hot spring sediment samples collected from Tibet, western China. Phylogenetic analyses based on 16S rRNA gene sequence similarities showed that two isolates belonged to the genus Microvirga and were most closely related to Microvirga makkahensis SV1470T (98.5% and 98.4%, respectively) and two strains had 99.8% similarity to each other. The average nucleotide identity (ANI) based on whole genome sequences of two strains and M. makkahensis SV1470T was 80.8% and 80.78%, respectively. Optimum growth was observed at 45 °C, pH 7.0 and 0.5% NaCl. They both could tolerate to high concentration arsenic. Ubiquinone 10 (Q10) was their predominant quinone. The differences of strains 3D203T and 3D207 were phosphatidyl dimethyl ethanolamine, phosphatidyl-N-methylethanolamine, phosphatidylglycerol, unidentified glycolipids and unidentified lipids. The major fatty acids (> 5%) were identified C18:1ω7c and/or C18:1ω6c, C18:0 and C16:0. The genomic DNA G + C contents of strain 3D203T and 3D207 based on whole genome sequences were 64.8% and 64.7%, respectively. Phenotypic, chemotaxonomic, phylogenetic and genomic analyses suggested that two strains represent a novel species of the genus Microvirga, for which the name Microvirga arsenatis sp. nov. is proposed. The type strain is 3D203T (= CGMCC 1.17691T = KCTC 72653T).

A nosocomial cluster of Roseomonas mucosa bacteremia possibly linked to contaminated hospital environment.

Roseomonas, a genus of pink-pigmented glucose non-fermentative bacteria, has been associated with various primary and hospital-acquired human infections; however, to our knowledge, its nosocomial transmission has never been reported. Clinical and epidemiological investigations were carried out after two cases of R. mucosa bacteremia occurred in our hospital in 2018. Environmental samples were taken of environmental surfaces prone to water contamination in the wards and cultured. The two clinical isolates and all environmental isolates that showed growth of pink colonies were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry and 16S rRNA gene sequencing. Pulse-field gel electrophoresis (PFGE) was performed and fingerprinting software was used to analyze the DNA restriction patterns and determine their similarity. Two patients who developed R. mucosa bacteremia had received care from the same treatment team. Of 126 environmental samples, five showed growth of R. mucosa. Using 80% similarity as the cut-off, PFGE analysis revealed that the isolates from the two patients' blood cultures and three environmental isolates belonged to the same clone. The hospital water environment was contaminated with the same clone of R. mucosa that caused bacteremia in the two patients, suggesting nosocomial transmission linked to contaminated environment. Increased vigilance is needed to monitor the emergence of Roseomonas in healthcare settings.

Roseomonas gilardii Bacteremia in a Patient With HbSß0-thalassemia: Clinical Implications and Literature Review.

Roseomonas gilardii is a Gram-negative coccobacillus identified in immunocompromised pediatric patients. A 5-year-old male with a history of HbSß thalassemia status postsurgical splenectomy presented to the emergency department with fever. Blood cultures grew R. gilardii at 63 hours, but the patient had been discharged home at 48 hours. The patient was readmitted for repeat cultures and initiated on meropenem for 10 days as Roseomonas spp. are often resistant to third generation cephalosporins. R. gilardii is a rare cause of bacteremia in immunocompromised patients. Clinicians should consider Roseomonas in slow growing Gram-negative rod bacteremias, and consider meropenem as empiric coverage.

Microvirga sp. symbiovar mediterranense nodulates Lupinus cosentinii grown wild in Morocco.

AIM: To analyse the diversity of nodule-forming bacteria isolated from Lupinus cosentinii naturally grown in the Maamora cork oak forest (Rabat, Morocco). METHODS AND RESULTS: Of the 31 bacterial strains, four were selected based on their REP-PCR fingerprinting that were studied by sequencing and phylogenetic analysis of their 16S rRNA, gyrB, dnaK, recA and rpoB housekeeping genes as well as the nodC symbiotic gene. The nearly complete 16S rRNA gene sequence of the four representative strains showed that they are related to Tunisian strains of genus Microvirga isolated from L. micranthus with nucleotide identity values ranging from 98·67 to 97·13%. The single and concatenated sequences of the 16S rRNA, gyrB, dnaK, recA and rpoB housekeeping genes indicated that the L. cosentinii-isolated strains had 99·2-99·9% similarities with the Tunisian L. micranthus microsymbionts. The nodC gene phylogeny revealed that the Moroccan strains clustered in the newly described mediterranense symbiovar, and nodulation tests showed that they nodulated not only L. cosentinii but also L. angustifolius, L. luteus and L. albus. CONCLUSIONS: To the best of our knowledge, this is the first report concerning the isolation, molecular identification and phylogenetic diversity of L. cosentinii nodule-forming endosymbionts and of their description as members of the Microvirga genus. SIGNIFICANCE AND IMPACT OF THE STUDY: In this work, we show that Microvirga sp. can be isolated from root nodules of wild-grown L. cosentinii in Northeast Africa, that selected strains also nodulate L. angustifolius, L. luteus and L. albus, and that they belong to symbiovar mediterranense. In addition, our data support that the ability of Microvirga to nodulate lupines could be related to the soil pH, its geographical distribution being more widespread than expected.

Roseomonas vastitatis sp. nov. isolated from Badain Jaran desert in China.

A Gram-stain-negative, non-motile, coccobacillus-shaped bacterium, designated CPCC 101021T, was isolated from a sandy soil sample collected from Badain Jaran desert, China. Its 16S rRNA gene sequence was closely related to those of members of the genus Roseomonas, showing high similarities with Roseomonas hibiscisoli THG-N2.22T (98.0 %), Roseomonas oryzae KCTC 42542T (97.9 %), Roseomonas rhizosphaerae YW11T (97.9 %) and Roseomonas suffusca S1T (97.8 %). In the phylogenetic tree based on 16S rRNA gene sequences, strain CPCC 101021T formed a distinct subclade with R. oryzae KCTC 42542T within the genus Roseomonas. Growth of the isolate occurred at 15-37 °C and pH 6.0-8.5, with optimal growth at 30 °C and pH 7.0. The major cellular fatty acids were C18 : 1ω7c, summed feature 8 (C16 : 1ω7c/C16 : 1ω6c), summed feature 3 (C16 : 1ω6c/C16 : 1ω7c) and C16 : 0ω6c. Q-10 was detected as the main component in the respiratory quinone system, with Q-9 as a minor component. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, an unidentified phospholipid, an unidentified aminolipid and an unidentified glycolipid were found in the polar lipid profile. The genomic DNA G+C content was 68.7 mol%. The average nucleotide identity was 84.6 % when comparing the draft genome sequences of strain CPCC 101021T with R. oryzae KCTC 42542T. On the basis of genotypic, chemotaxonomic and phenotypic characteristics, strain CPCC 101021T is proposed to represent a novel species of the genus Roseomonas with the name Roseomonas vastitatis sp. nov. Strain CPCC 101021T (=J1A743T=KCTC 62043T) is the type strain of the species.