Pontibacter cellulosilyticus sp. nov., a carboxymethyl cellulose-hydrolysing bacterium isolated from coastal water

A Gram-stain-negative, rod-shaped, non-motile, red-pink bacterium designated SD6^T was isolated from coastal marine water at Sadong Beach, Ulleung Island, South Korea. Cells of SD6^T grew at 10-42 °C (optimum, 30 °C), pH 5.0-9.0 (optimum, pH 6.0-7.0) and at 0-8.0 % (w/v) NaCl (optimum, 0-3 %). Moreover, 16S rRNA gene sequence analysis indicated that strain SD6^T was a member of the genus Pontibacter, sharing similarities to Pontibacter aydingkolensis XAAS-1^T (98.0 %), Pontibacter amylolyticus 9-2^T (97.3 %), Pontibacter korlensis X14-1^T (97.2 %) and Pontibacter soli HYL7-26^T (96.8 %). The predominant fatty acids of strain SD6^T were identified as iso-C_15 : 0 and summed feature 4 (comprising anteiso-C_17 : 1 B and/or iso-C_17 : 1 I) and the sole respiratory quinone was identified as MK-7 (menaquinone 7). Major polar lipids included phosphatidylethanolamine, one unidentified phosphoglycolipid, two unidentified glycolipids and one unidentified lipid. The average nucleotide identity and in silico DNA-DNA hybridization values of strain SD6^T with its closely related strains were 72.8-79.8 % and 19.2-22.6 %, respectively. The genomic DNA G+C content was 45.4 mol%. In accordance with the results of phenotypic, chemotaxonomic and phylogenetic data, strain SD6^T represents a novel species of the genus Pontibacter, for which the name Pontibacter cellulosilyticus sp. nov. is proposed. The type strain is SD6^T (=KACC 21543^T=NBRC 114313^T=JCM 31022^T).

Sphingosinicella flava sp. nov., indole acetic acid producing bacteria isolated from maize field soil

A novel isolated yellow-pigmented bacterial designated strain UDD2^T was isolated from a maize field soil sample collected in Ilsan, Republic of Korea. Cells of strain UDD2^T were Gram-stain-negative, non-sporulating, long rod-shaped and exhibited flagellar motility. Cells could grow at 15-42 °C and pH 5.5-11.0. Strain UDD2^T was sensitive to NaCl and barely tolerated up to 1 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain UDD2^T formed a separate clade with the members of genus Sphingosinicella within the family Sphingomonadaceae. Strain UDD2^T showed the highest 16S rRNA gene sequence similarity to Sphingosinicella vermicomposti KCTC 224446^T (98.5 %) and Sphingosinicella humi KCTC 62519^T (96.7 %), followed by members of the genus Sphingomonas (96.4-94.5 %) and Sphingobium (96.1-94.9 %), but they were located in other phylogenetic clusters. Average nucleotide identity and digital DNA-DNA hybridization values between strain UDD2^T and S. vermicomposti KCTC 224446^T and S. humi KCTC 62519^T were 80.2/24.2 and 75.6/20.4 %, respectively. The total size of the genome was 2 421 697 bp and composed of one circular chromosome, with a G+C content of 63.7 mol%. Strain UDD2^T produced indole acetic acid (IAA) in the presence of l-tryptophan. Bacterial IAA is a crucial phytohormone in plant growth and development. Gene clusters for indole-3-glycerol phosphate synthase and tryptophan synthase were found in the genome of strain UDD2^T. To the best of our knowledge, no member of the genus Sphingosinicella has been reported to produce IAA to date. The major cellular fatty acids (>10 %) were found to be C_16 : 0, C_14 : 0 2OH and summed feature 3 (comprising C_{16  : 1} ω7c and/or iso-C_{15  :  0} 2-OH). Strain UDD2^T had ubiquinone Q-10 as the major respiratory quinone and homospermidine as the major polyamine. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, phosphatidylglycerol, phosphatidylcholine, three unidentified phosphoglycolipids, one unidentified phospholipid, one unidentified aminoglycophospholipid, one unidentified glycolipid and one unidentified polar lipid. Based on the phylogenetic, phenotypic, chemotaxonomic and genotypic data, strain UDD2^T represents a novel species of the genus Sphingosinicella, for which the name Sphingosinicella flava is proposed. The type strain is UDD2^T (=KCTC 82357^T=NBRC 114507^T).

Flavobacterium tagetis sp. nov., a novel urea-hydrolysing bacterium isolated from the roots of Tagetes patula

A Gram-stain-negative, rod-shaped, motile by gliding, non-sporulating and strictly aerobic bacterium, designated strain GN10^T, was isolated from the roots of Tagetes patula, collected from the garden of Dongguk University, Goyang, Republic of Korea. The cells could grow at 10-42 °C and at pH 5.5-9.0. Strain GN10^T was sensitive to NaCl and tolerated up to 4 % NaCl (w/v). Comparative analysis of 16S rRNA gene sequences revealed the highest similarities to Flavobacterium tistrianum GB 56.1^T (98.9 %), Flavobacterium sharifuzzamanii A7.6^T (98.6 %), Flavobacterium zhairuonense A5.7^T (98.3 %) and Flavobacterium anhuiense D3^T (98 %). Phylogenetic analysis showed that strain GN10^T clustered within the genus Flavobacterium and formed a monophyletic cluster with its close relative members. The average nucleotide identity and digital DNA-DNA hybridization values between strain GN10^T and related species belonging to the genus Flavobacterium were well below the standard threshold for prokaryotic species delineation. The DNA G+C content of strain GN10^T was 33.6 mol%. The predominant cellular fatty acids (>10 %) were identified as iso-C_15 : 0, C_16 : 0 and summed feature 3 (C_{16  : 1} ω6c and/or C_{16  :  1} ω7c). Strain GN10^T contained menaquinone 6 as the major respiratory quinone. The major polar lipids were phosphatidylethanolamine, three unidentified aminoglycolipids, two unidentified glycolipids, one unidentified phosphoglycolipid and five unidentified lipids. Urease is a nickel-containing enzyme found in archaea, bacteria, plants and unicellular eukaryotes. It serves as a virulence factor and is responsible for pathogenesis in humans and animals. Here, we describe a novel urease-hydrolysing bacterium, strain GN10^T. The urease activity of this strain may serve as an indicator of pathogenic potential and drug resistance, which may facilitate the development of many diseases. The results of physiological and biochemical tests allowed the genotypic and phenotypic differentiation of strain GN10^T from its closely related members and considered to represent novel species in the genus Flavobacterium, for which the name Flavobacterium tagetis (GN10^T=KCTC 82695^T=NBRC 114841^T) is proposed.

Nocardioides baculatus sp. nov., a novel actinomycete isolated from the rhizosphere of Tagetes patula

An aerobic, Gram-stain-positive, non-motile, dull-yellow, short rod-shaped actinomycete strain, designated G10^T, was isolated from Tagetes patula (marigold) roots collected from Goyang in the Republic of Korea. The isolate showed best growth on Reasoner's 2A agar at 25 °C, pH 6.5.0 and with 0% NaCl (w/v). The strain was negative for oxidase activity and positive for catalase activity. On the basis of 16S RNA gene sequence similarity, strain G10^T was affiliated to the genus Nocardioides and the closest species were Nocardioides glacieisoli HLT3-15^T (98.8 %), Nocardioides zhouii HLT2-9^T (98.8 %), Nocardioides ganghwensis JC2055^T (98.7 %), Nocardioides cavernae YIM A1136^T (98.6 %), Nocardioides flavus Y4^T (98.5 %), Nocardioides oleivorans DSM 16090^T (98.3 %), Nocardioides alpinus Cr7-14^T (98.2 %), Nocardioides exalbidus DSM 22017^T (98.1 %) and Nocardioides hwasunensis KCTC 19197^T (98.1 %). Strain G10^T formed a monophyletic cluster with N. glacieisoli HLT3-15^T, N. zhouii HLT2-9^T and N. hwasunensis KCTC 19197^T in all phylogenetic trees. The cell-wall peptidoglycan of strain G10^T contained ll-diaminopimelic acid as the diagnostic amino acid. The predominant fatty acids were iso-C_16 : 0 and C_17 : 1  ω8c. MK-8(H₄) was the major isoprenoid quinone. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol. Average nucleotide identity and digital DNA-DNA hybridization values were 78.6-88.7 % and 21.5-36.2 %, respectively, with the type strains of related species of the genus Nocardioides, suggesting that strain G10^T represents a novel species. The genome of strain G10^T is 4 231 000 bp long with a DNA G+C content of 71.5 mol% and encodes 4071 predicted proteins, six rRNAs and 46 tRNAs. The genome of strain G10^T comprises the biosynthetic gene cluster for T3PKS, terpene, NRPS-like fragment and RRE-containing element as secondary metabolites. The results of taxonomic, phylogenetic, biochemical, chemotaxonomic and genomic analysis clearly supported that strain G10^T represent a novel species within the genus Nocardioides, for which the name Nocardioides baculatus sp. nov is proposed and the type strain is G10^T (=KCTC 49626^T=NBRC 114801^T).

Oryzicola mucosus gen. nov., sp. nov., a novel slime producing bacterium belonging to the family Phyllobacteriaceae isolated from the rhizosphere of rice plants

A novel Gram-stain negative, asporogenous, slimy, rod-shaped, non-motile bacterium ROOL2^T was isolated from the root samples collected from a rice field located in Ilsan, South Korea. Phylogenetic analysis of the 16S rRNA sequence showed 96.5% similarity to Tianweitania sediminis Z8^T followed by species of genera Mesorhizobium (96.4-95.6%), Aquabacterium (95.9-95.7%), Rhizobium (95.8%) and Ochrobactrum (95.6%). Strain ROOL2^T grew optimally at 30 °C in the presence of 1-6% (w/v) NaCl and at pH 7.5. The major respiratory quinone was ubiquinone-10 and the major cellular fatty acids were C_18:1ω7c, summed feature 4 (comprising iso-C_17:1 I and/or anteiso-C_17:1 B) and summed feature 8 (comprising C_18:1ω6c and/or C_18:1ω7c). The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylmethylethanolamine, phosphatidylglycerol, one unidentified aminolipid and two unidentified lipids. The assembled draft genome of strain ROOL2^T had 28 contigs with N50 value of 656,326 nt, total length of 4,894,583 bp and a DNA G + C content of 61.5%. The average amino acid identity (AAI) values of strain ROOL2^T against the genomes of related members belonging to the same family were below 68% and the ANI and dDDH values between the strain ROOL2^T and the type strains of phylogenetically related species were 61.8-76.3% and 19.4-21.1%, respectively. Strain ROOL2^T only produces carotenoid-type pigment when grown on LB agar and slime on R2A agar. In the presence of tryptophan, strain ROOL2^T produced indole acetic acid (IAA), a phytohormone in plant growth and development. Gene clusters for indole-3-glycerol phosphatase and tryptophan synthase were found in the genome of strain ROOL2^T. The genotypic and phenotypic characteristics indicated that strain ROOL2^T represents a novel genus belonging the family Phyllobacteriaceae, for which the name Oryzicola mucosus gen. nov., sp. nov. is proposed. The type strain is ROOL2^T (KCTC 82711 ^T = NBRC 114717 ^T).

Limnohabitans radicicola sp. nov., a slow-growing bacterium isolated from rhizosphere of rice plant and emended description of the genus Limnohabitans

In the present study, in an attempt to explore the diversity of bacteria in the roots of rice plants, a Gram-stain-negative, motile, facultatively anaerobic, non-pigmented, catalase-positive, oxidase-negative and rod-shaped bacterium with polar flagella was isolated. Phylogenetic analysis based on 16S rRNA gene sequences revealed highest sequence similarity to Limnohabitans parvus KCTC 42859^T (98.2%) followed by Limnohabitans curvus KCTC 42562^T (98%), Limnohabitans planktonicicus II-D5^T (97.9%) and Limnohabitans australis MWH-BRAZ-DAM2D^T (97.4%). Growth of strain JUR4^T occurred at 10-37 °C (optimum, 30 °C), at pH 5.5-8.0 (optimum, 6.5-7) and in the presence of 0-0.2% NaCl (optimum, 0%, w/v). The genome size of strain JUR4^T was found to be 3.34 Mb containing 3139 predicted protein-coding genes with a DNA G+C content of 61.5 mol%. The digital DNA-DNA hybridization and average nucleotide identity values between the genome sequence of strain JUR4^T and closely related reference strains were 21.0-24.8% and 74.7-81.4%, respectively. Strain JUR4^T contained diphosphatidylglycerol, phoshatidylethanolamine, one unidentified phosphoglycolipid, one unidentified aminophosphoglycolipid, one unidentified phospholipid and seven unidentified glycolipids. The major fatty acids were C_16:0 and summed feature 3 (comprising C_16:1 ω7c and/or C_16:1 ω6c), and ubiquinone Q-8 was the sole isoprenoid quinone. So far, all species belonging to the genus Limnohabitans have been described as non-motile and devoid of flagella. All species were isolated from freshwater and are therefore denoted as planktonic bacteria. This present study introduces a novel motile member of Limnohabitans isolated from the root of rice plant, and introduces the genes associated with motility and methyl-accepting chemotaxis proteins. Phylogenetic, phenotypic, chemotaxonomic and genotypic data clearly indicates that strain JUR4^T represents a novel species of the genus Limnohabitans for which the name Limnohabitans radicicola sp. nov. is proposed. The type strain is JUR4^T (=KACC 21745^T=NBRC 114484^T).

Sphingomonas sabuli sp. nov., a carotenoid-producing bacterium isolated from beach sand

A Gram-stain-negative, aerobic and non-motile bacterium, strain sand1-3^T, was isolated from beach sand collected from Haeundae Beach located in Busan, Republic of Korea. Based on the results of 16S rRNA gene sequence and phylogenetic analyses, Sphingomonas daechungensis CH15-11^T (97.0 %), Sphingomonas edaphi DAC4^T (96.8 %), Sphingomonas xanthus AE3^T (96.5 %) and Sphingomonas oryziterrae YC6722^T (96.0 %) were selected for comparing phenotypic and chemotaxonomic characteristics. Cells of strain sand1-3^T grew at 7-50 °C (optimum, 30-35 °C), pH 5.0-8.0 (optimum, pH 7.0-8.0) and in the presence of 0-0.5 % (w/v) NaCl (optimum, 0 %). Major polar lipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid, one unidentified glycolipid and one unidentified phosphoglycolipid. The major fatty acids were summed feature 8 (C_18 : 1 ω6c and/or C_18 : 1 ω7c) and C_18 : 1 2-OH. Moreover, the sole respiratory quinone and major polyamine were identified as ubiquinone-10 and homospermidine, respectively. The genomic DNA G+C content was 65.9 mol%. The digital DNA-DNA hybridization, average nucleotide identity and average amino acid identity values of strain sand1-3^T and its reference strains with publicly available genomes were 17.9-18.9 %, 72.0-75.3 % and 63.3-76.5 % respectively. Based on polyphasic evidence, we propose Sphingomonas sabuli sp. nov. as a novel species within the genus Sphingomonas. The type strain is sand1-3^T (=KCTC 82358^T=NBRC 114538^T).

Chryseobacterium caseinilyticum sp. nov., a casein hydrolyzing bacterium isolated from rice plant and emended description of Chryseobacterium piscicola

A novel Gram-stain-negative, aerobic, asporogenous, catalase-positive and oxidase-negative, non-motile, golden-yellow pigmented, rod-shaped bacterium with casein-degrading ability, designated strain GCR10^T, was isolated from roots of rice plants collected from a paddy field near Dongguk University, Republic of Korea. The results of subsequent 16S rRNA gene sequence analysis indicated that GCR10^T shares the highest sequence identity with Chryseobacterium piscicola VQ-6316s^T (98.3%). Strain GCR10^T grew at 2-32 °C (optimum, 25 °C), at pH 6.0-8.0 (optimum, pH 7.0) and in the presence of 0-2.0% (w/v) NaCl (optimum in the absence of NaCl). The novel strain was able to produce carotenoid and flexirubin-type pigments. The predominant menaquinone was MK-6 and the major fatty acids were identified as iso-C_{15 : 0}, iso-C_{17 : 0} 3-OH and iso-C_{17 : 1}ω9c. The polar lipids were phosphatidylethanolamine, four unidentified aminoglycolipids, two unidentified aminolipids and two unidentified glycolipids. The genome of GCR10^T is 4.3 Mb in length with a DNA G+C content of 36.5 mol%. Average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values between GCR10^T and Chryseobacterium piscicola VQ-6316s^T were 82.1, 25.2 and 84.3 %, respectively, which clearly indicates that the novel strain is distinct from its closest relative. The demand for natural biodegradable pigments isolated frominsects, plants or microorganisms is increasing day by day because of their beneficial pharmacological properties. Here, we describe a novel strain that produces two types of pigment, carotenoid and flexirubin. On the basis of the results from phenotypic, genotypic and chemotaxonomic analyses, strain GCR10^T represents a novel species of the genus Chryseobacterium, and the name Chryseobacterium caseinilyticum sp. nov. is proposed. The type strain is GCR10^T (=KACC 21707^T=NBRC 114715^T).

Cohnella terricola sp. nov., isolated from soil

A Gram-positive, aerobic, flagellated, endospore-forming, rod-shaped strain, designated as G13^T, was isolated from soil. The results of 16S rRNA gene sequence analysis led to the conclusion that strain G13^T was phylogenetically related to Cohnella boryungensis BR29^T (97.5 %) and Cohnella phaseoli CECT 7287^T (96.9 %) with digital DNA-DNA hybridization values of 21.0 and 21.4 %, and distantly related to Cohnella thermotolerans CCUG 47242^T (94.8 %), type species of the genus Cohnella, at 19.0 %. The genome size of strain G13^T was 5 387 258 bp, with 51.3 mol% G+C content. The predominant fatty acids were summed feature 9 (iso-C_17 : 1  ω9c and/or C_16 : 0 10-methyl), anteiso-C_17 : 0, iso-C_17 : 0 and iso-C_15 : 0. The predominant quinone was menaquinone-7 and the major polar lipids were diphosphatidyglycerol, phosphatidylethanolamine, phosphatidylglycerol, lysylphosphatidylglycerol, three aminophospholipids, two phosphoglycolipids, three aminolipids and two unidentified lipids. Based on the data from phenotypic tests and the genotypic differences between strain G13^T and its close phylogenetic relatives, strain G13^T represents a new species belonging to the genus Cohnella, for which the name Cohnella terricola sp. nov. (=KACC 19905^T=NBRC 113748^T) is proposed.

Clinical and electrophysiological characteristics of extra-pulmonary vein triggers in patients who underwent catheter ablation for atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Extra-pulmonary vein (PV) triggers play significant roles in atrial fibrillation (AF) recurrence after AF catheter ablation (AFCA).

Purpose

We explore the clinical and electrophysiological characteristics of extra-PV triggers in de novo and repeat-AFCA procedure.

Methods

We included 2,151 patients who had de novo AFCA and 319 repeat AFCA (female 28.0%, 59.1 ± 10.8 years old, paroxysmal AF 65.1%) those underwent post-procedural isoproterenol (ISO) provocation tests. We analysed the clinical, electrophysiological, and procedure-related factors associated with extra-PV triggers.

Results

Extra-PV triggers were documented in 11.9% (1.19 ± 0.42 foci) after de novo-AFCA and 27.0% (1.37 ± 0.65 foci) after repeat-AFCA (p = 0.004). LA volume index (OR 1.02 [1.01-1.03], p = 0.004), history of vascular disease (OR 0.55[0.31-0.91], p = 0.028) and Lead I amplitude of electrocardiogram (OR <0.01 [<0.01-0.62], p = 0.032) were independently associated with the existence of extra-PV triggers in de-novo procedure. Women (OR 1.84 [1.03-3.25], p = 0.037) and LA appendage volume (OR 1.04 [1.01-1.07] p = 0.027) were independently associated with extra-PV triggers during the redo-mapping procedure. Septum (28.4%), coronary sinus (24.0%), and superior vena cava (19.6%) were common extra-PV foci, and septal foci were more commonly found in repeat mapping (38.4% vs. 25.0%, p = 0.025). Among 65 patients who showed extra-PV at the repeat procedures, 19 (29.2%) matched with previous focal or empirical extra-PV ablation sites and 9 (13.8%) were multiple or unmappable sites. AF recurrence rates were significantly higher in both patients with extra-PV triggers after de novo procedures (Log-rank P <0.001; HR 1.93 [1.58-2.36], p= <0.001) and repeat procedures (Log-rank P <0.001, HR 1.87 [1.29-2.70], p= <0.001).

Conclusion

ISO provoked extra-PV triggers commonly found in AF patients with significant remodelling and previous empirical or focal extra-PV ablations. Existence of extra-PV triggers were independently associated with poorer rhythm outcome after both de novo and repeat AFCA. Denovo AF ablation outcome OverallExtra-PV triggers (-)Extra-PV triggers (+)p-value(n = 2151)(n = 1895)(n = 256)Age, yrs58.98 ± 10.9558.73 ± 11.0360.76 ± 10.200.006Male, (%)1550 ( 72.1)1389 ( 73.3)161 ( 62.9)0.001Follow up duration, month50.30 (37.71)51.65 (37.95)40.71 (34.58)<0.001Early recurrence (%)579 ( 27.8)455 ( 24.9)124 ( 48.4)<0.001Clinical recurrence (%)699 ( 33.6)584 ( 32.0)115 ( 44.9)<0.001Abstract Figure. AF free survival according to Extra PVT

Sympathetic predominance before tourniquet deflation is associated with a reduction in arterial blood pressure after tourniquet deflation during total knee arthroplasty

High dependency of arterial blood pressure (ABP) on enhanced sympathetic activity, which maintains vascular tone, leads to hypotension after hemodynamic insults that blunt the sympathetic activity. Therefore, we hypothesized that sympathovagal balance before tourniquet deflation (TD) determines the extent of a reduction in ABP after TD during total knee arthroplasty (TKA). Fifty-four hypertensive female patients undergoing TKA under spinal anesthesia were analyzed. The sympathovagal balance [low-to-high frequency ratio of heart rate variability (LF/HF)] before TD was defined as (LF/HF during 5 min before TD-preanesthetic LF/HF)/preanesthetic LF/HF (%). An increase in its value represents a shift in sympathovagal balance toward sympathetic predominance. The percent change in the mean ABP (MAP) after TD was defined as (minimum MAP during 10 min after TD-averaged MAP during 5 min before TD)/averaged MAP during 5 min before TD (%). Simple linear regression was performed to assess the correlation between the sympathovagal balance before TD and change in MAP after TD. The correlation was also assessed by multiple linear regression controlling for age, duration of tourniquet inflation, and spinal anesthesia-induced hypotension. Thirty-two minutes (on average) after tourniquet inflation, the MAP was decreased by 12.1 (-3.0 to 47.9) % [mean (range)] upon TD (P<0.001). The sympathovagal balance before TD was negatively proportional to the change in MAP after TD in both simple and multiple linear regression models (R2=0.323 and 0.340, P<0.001). A shift in sympathovagal balance toward sympathetic predominance before TD is associated with a decrease in ABP after TD.

317 Why Are We Cancelling Theatre Cases at Ealing Hospital? What Can Be Done?

Introduction

Following a recent spate of on the day cancellation of elective operations being cancelled on the day of surgery, a need for a wider review was felt. Our aim was to identify the causes behind these cancellations.

Method

Retrospective data collection was performed to categorise patients according to the reason for cancellation. Analysis consisted of case presentations being prepared and presented to the surgical consultants.

Results

A total of 130 operations were cancelled on the day of surgery. 22 patients were cancelled due to the procedure not being required and 10 patients were cancelled due to insufficient pre-operative investigations.

Analysis of the 32 cases demonstrated that the majority of cancelled patients were seen and listed for surgery after clinical review by the registrar without involvement of the consultant.

Some cancellations occurred when the consultant responsible for listing the patient was different of the operating consultant.

Both factors lead to differences in opinion arising on the day of surgery.

Conclusions

Ensuring patients are only listed after discussion with the consultant would reduce cancellations arising from lack of experience and clinical misjudgment of the registrar. It would also ensure that cases added to the pooled operating lists are less subjective in their indication and readiness.

Flavobacterium baculatum sp. nov., a carotenoid and flexirubin-type pigment producing species isolated from flooded paddy field

A Gram-stain-negative, aerobic, asporogenous, motile by gliding, dull-yellow, long rod-shaped bacterial strain, designated SNL9^T, was isolated from a flooded paddy field near Dongguk University, Republic of Korea. The results of phylogenetic analyses based on 16S rRNA gene sequences indicated that SNL9^T represents a member of the genus Flavobacterium and is most closely related to Flavobacterium ummariense DS-12^T (96.2%) and Flavobacterium viscosum YIM 102796^T (96.3%). The average nucleotide identity and in silico DNA-DNA hybridization (DDH) values with F. ummariense DS-12^T and F. viscosum YIM 102796^T were 89.3/39.1 and 87.1/33 %, respectively. The major fatty acids of SNL9^T were identified as iso-C_15 : 0, summed feature 3 (comprising C_{16  :  1}ω6c and/or C_{16  :  1}ω7c) and summed feature 9 (comprising iso-C_17 : 1ω9c and/or 10 methyl C_16 : 0). SNL9^T contained MK-6 as the major respiratory quinone. The polar lipids were phoshatidylethanolamine, one unidentified aminophosphoglycolipid, three unidentified aminoglycolipids, two unidentified glycolipids and one unidentified phosphoglycolipid. The DNA G+C content was 34.2 mol%. SNL9^T produces carotenoid and flexirubin-type pigments. Among them, carotenoids are particularly valuable for the biotechnological and pharmaceutical industries due to their antioxidant activity. Aryl polyenes (APE) pigments were also found in SNL9^T which are responsible for yellow pigment in bacteria. They are stored in the bacterial membrane and protect the bacteria from oxidative stress, particularly from reactive oxygen species. In this paper, we describe a novel isolate, SNL9^T, which protect itself from the attack of free radicals using specific natural products in the membrane. Because of their anti-oxidation properties, aryl polyenes may also be of interest to the cosmetic industry. On the basis of the results of phenotypic, genotypic and chemotaxonomic analyses, SNL9^T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium baculatum sp. nov. is proposed. The type is SNL9^T (=KACC 21170^T=NBRC 113746^T).

Liposomal irinotecan plus fluorouracil/leucovorin versus FOLFIRINOX as the second-line chemotherapy for patients with metastatic pancreatic cancer: a multicenter retrospective study of the Korean Cancer Study Group (KCSG)

Background

There is no clear consensus on the recommended second-line treatment for patients with metastatic pancreatic cancer who have disease progression following gemcitabine-based therapy. We retrospectively evaluated the clinical outcomes of liposomal irinotecan (nal-IRI) plus fluorouracil/leucovorin (FL) and FOLFIRINOX (fluorouracil, leucovorin, irinotecan, and oxaliplatin) in patients who had failed on the first-line gemcitabine-based therapy.

Patients and methods

From January 2015 to August 2019, 378 patients with MPC who had received nal-IRI/FL (n = 104) or FOLFIRINOX (n = 274) as second-line treatment across 11 institutions were included in this retrospective study.

Results

There were no significant differences in baseline characteristics between groups, except age and first-line regimens. With a median follow-up of 6 months, the median progression-free survival (PFS) was 3.7 months with nal-IRI/FL versus 4.6 months with FOLFIRINOX (P = 0.44). Median overall survival (OS) was 7.7 months with nal-IRI/FL versus 9.7 months with FOLFRINOX (P = 0.13). There was no significant difference in PFS and OS between the two regimens in the univariate and multivariate analyses. The subgroup analysis revealed that younger age (<70 years) was associated with better OS with FOLFIRINOX. In contrast, older age (≥70 years) was associated with better survival outcomes with nal-IRI/FL. Adverse events were manageable with both regimens; however, the incidence of grade 3 or higher neutropenia and peripheral neuropathy was higher in patients treated with FOLFIRINOX than with nal-IRI/FL.

Conclusions

Second-line nal-IRI/FL and FOLFIRINOX showed similar effectiveness outcomes after progression following first-line gemcitabine-based therapy. Age could be the determining factor for choosing the appropriate second-line therapy.

•

This multicenter retrospective study investigated nal-IRI/FL and FOLFIRINOX outcomes after gemcitabine-based therapy.

•

We found no significant differences in outcome between nal-IRI/FL and FOLFIRINOX treatment.

•

Both regimens were well tolerated; however, neutropenia and peripheral neuropathy were more frequent with FOLFIRINOX.

•

Age (cut-off, 70 years) showed differential efficacy between chemotherapy regimens.

Lewinella aurantiaca sp. nov., a carotenoid pigment-producing bacterium isolated from surface seawater

A Gram-stain-negative, aerobic, rod-shaped, carotenoid-pigmented, motile-by-gliding bacterium, which was designated as SSH13T, was isolated from a surface seawater sample collected from Sehwa Beach in the Republic of Korea. Strain SSH13T was oxidase-negative, catalase-positive and grew at 2–37 °C (optimum, 30 °C), in the presence of 0.5–6% NaCl and within a pH range of pH 6–10 (optimum, pH 8). The novel isolate required NaCl for growth and grew optimally with approximately 2 % NaCl. Chemotaxonomic and morphological characteristics were consistent with members of the genus Lewinella . Furthermore, phylogenetic analysis based on 16S rRNA gene sequencing revealed that strain SSH13T was most closely related to the type strains of the genus Lewinella . Strain SSH13T had highest 16S rRNA gene sequence similarities to Lewinella persica DSM 23188T (95.3 %) and Lewinella agarilytica KCTC 12774T (95.0 %). The major fatty acids of SSH13T were summed feature 3 (C16 : 1  ω7c and/or C16 : 1  ω6c) and iso-C15 : 0. Strain SSH13T contained phosphatidylethanolamine as a major polar lipid. Menaquinone-7 was the predominant respiratory quinone. The average nucleotide identity values between strain SSH13T and L. persica T-3T and L. agarilytica SST-19T were 72.9 and 72.6 %, respectively. The DNA G+C content of the genomic DNA was 52.8 mol%. The present study aimed to determine the multiple-antibiotic resistance of the novel bacterium. Based on phylogenetic and phenotypic analyses, strain SSH13T is considered to represent a novel species of the genus Lewinella , for which the name Lewinella aurantiaca sp. nov. (type strain SSH13T=KACC 21167T=NBRC 113866T) is proposed.

Reinekea thalattae sp. nov., a New Species of the Genus Reinekea Isolated from Surface Seawater in Sehwa Beach

A Gram-stain-negative, non-pigmented, curved rod-shaped, single polarly flagellated, facultatively anaerobic bacterium, designated as SSH23^T, was isolated from surface seawater sample collected at the Sehwa Beach in South Korea. The novel isolate required NaCl for growth and grew optimally between 2 and 3% NaCl. Strain SSH23^T showed high 16S rRNA gene sequence similarities with Reinekea marinisedimentorum DSM 15388^T (96.4%), Reinekea marina KACC 17315^T (96.2%), Reinekea blandensis KACC 17315^T (95.9%) and Reinekea aestuarii KCTC 22813^T (95.6%). The major polar lipids of strain SSH23^T were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The major cellular fatty acids of strain SSH23^T were C_16:0, summed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c), and summed feature 8 (C_18:1 ω7c and/or C_18:1 ω6c). The predominant respiratory quinone was found to be ubiquinone-8. The average nucleotide identity values of strain SSH23^T with R. marinisedimentorum DSM 15388^T and R. blandensis MED297^T were determined to be 72.2% and 69.8%, respectively. The G+C content of the genomic DNA was 45.5 mol%. Based on genotypic, phenotypic, chemotaxonomic, and phylogenetic analyses, strain SSH23^T was considered to represent a novel member of the genus Reinekea, for which the name Reinekea thalattae sp. nov. is proposed. The type strain of Reinekea thalattae is SSH23^T (= KACC 21168^T = NBRC 113795^T).

Adhaeribacter rhizoryzae sp. nov., a fibrillar matrix-producing bacterium isolated from the rhizosphere of rice plant

A novel fibrillar matrix-producing, rod-shaped, red–orange, asporogenous, aerobic bacterium, designated DK36T, was isolated from roots of a rice plant in the Ilsan region near Dongguk University, South Korea. Cells of strain DK36T were Gram-stain-negative and motile by means of gliding. The temperature and pH ranges for growth were 7–35 °C (optimum: 30 °C) and pH 5–10 (optimum: pH 7.0). The strain did not require NaCl for growth but tolerated up to 8 % (w/v) NaCl. Phylogenetic anlaysis of the 16S rRNA gene sequence revealed that DK36T formed a monophyletic clade with Adhaeribacter aerophilus 6425 S-25T, Adhaeribacter aerolatus 6515 J-31T and Adhaeribacter swui 17mud1-7T with sequence similarities of 96.3, 95.5 and 95.2%, respectively. The average nucleotide identity and in silico DNA–DNA hybridization values of strain DK36T with the most closely related strains whose whole genomes are publicly available were 72.5–83.6% and 19–28 %, respectively. The strain showed the typical chemotaxonomic characteristics of the genus Adhaeribacter , with the presence of menaquinone MK-7 as the respiratory quinone, and C16 : 1ω5c, iso-C15 : 0 and summed feature 4 (composed of iso-C17 : 1 I/anteiso-C17 : 1 B) as the major fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, one unidentified aminophosphoglycolipid, one unidentified phospholipid, two unidentified aminolipids and five unidentified polar lipids. The genomic DNA G+C content based on the draft genome sequence was 43.4 mol%. The results of physiological and biochemical tests and 16S rRNA gene sequence analysis clearly revealed that strain DK36T represents a novel species of the genus Adhaeribacter , for which the name Adhaeribacter rhizoryzae sp. nov. is proposed. The type strain is DK36T (=KACC 19902T=NBRC 113689T).

Changes of Neurotransmitters in Youth with Internet and Smartphone Addiction: A Comparison with Healthy Controls and Changes after Cognitive Behavioral Therapy

BACKGROUND AND PURPOSE

Neurotransmitter changes in youth addicted to the Internet and smartphone were compared with normal controls and in subjects after cognitive behavioral therapy. In addition, the correlations between neurotransmitters and affective factors were investigated.

MATERIALS AND METHODS

Nineteen young people with Internet and smartphone addiction and 19 sex- and age-matched healthy controls (male/female ratio, 9:10; mean age, 15.47 ± 3.06 years) were included. Twelve teenagers with Internet and smartphone addiction (male/female ratio, 8:4; mean age, 14.99 ± 1.95 years) participated in 9 weeks of cognitive behavioral therapy. Meshcher-Garwood point-resolved spectroscopy was used to measure γ-aminobutyric acid and Glx levels in the anterior cingulate cortex. The γ-aminobutyric acid and Glx levels in the addicted group were compared with those in controls and after cognitive behavioral therapy. The γ-aminobutyric acid and Glx levels correlated with clinical scales of Internet and smartphone addiction, impulsiveness, depression, anxiety, insomnia, and sleep quality.

RESULTS

Brain parenchymal and gray matter volume-adjusted γ-aminobutyric acid-to-creatine ratios were higher in subjects with Internet and smartphone addiction (P = .028 and .016). After therapy, brain parenchymal- and gray matter volume-adjusted γ-aminobutyric acid-to-creatine ratios were decreased (P = .034 and .026). The Glx level was not statistically significant in subjects with Internet and smartphone addiction compared with controls and posttherapy status. Brain parenchymal- and gray matter volume-adjusted γ-aminobutyric acid-to-creatine ratios correlated with clinical scales of Internet and smartphone addictions, depression, and anxiety. Glx/Cr was negatively correlated with insomnia and sleep quality scales.

CONCLUSIONS

The high γ-aminobutyric acid levels and disrupted balance of γ-aminobutyric acid-to-Glx including glutamate in the anterior cingulate cortex may contribute to understanding the pathophysiology and treatment of Internet and smartphone addiction and associated comorbidities.

Hymenobacter setariae sp. nov., isolated from the ubiquitous weedy grass Setaria viridis

A Gram-stain-negative, short-rod, aerobic, non-motile, red to pink-pigmented bacterium, designated Fur1T, was isolated from the dry spikelet clusters of a plant called Setaria viridis near Dongguk University. Phylogenetic analysis conducted based on 16S rRNA gene sequences indicated that strain Fur1T belonged to the genus Hymenobacter of the family Hymenobacteraceae . The 16S rRNA gene of Fur1T showed highest sequence similarity to those of Hymenobacter metalli KACC 17381T (97.5 %) and Hymenobacter marinus KACC 19042T (97.1 %). Growth occurred at 4–37 °C (optimum, 25–28 °C), up to 1.0 % NaCl (optimum, 0 %) and pH 5.5–9.0 (optimum, pH 6.0–7.5). The major fatty acids of strain Fur1T were identified as iso-C15 : 0, C16 : 1  ω5c, anteiso-C15 : 0, summed feature 3 (comprising C16 : 1  ω7c and/or C16 : 1  ω6c) and summed feature 4 (comprising anteiso-C17 : 1B and/or iso-C17 : 1I) as the major cellular fatty acids. The predominant respiratory quinone was identified as MK-7. The polar lipids were phosphatidylethanolamine, five unidentified aminophospholipids, two unidentified phospholipids, one unidentified glycolipid and one unidentified polar lipid. The genomic DNA G+C content based on the draft genome sequence was 58.7 mol%. DNA–DNA relatedness between strain Fur1T and its closest relative was below 70 %. Characterization based on phylogenetic, chemotaxonomic and phenotypic analyses clearly indicated that strain Fur1T represents a novel species of the genus Hymenobacter , for which the name Hymenobacter setariae sp. nov. is proposed. The type strain is Fur1T (=KACC 19903T=NBRC=113691T).

Enhanced antimicrobial stewardship based on rapid phenotypic antimicrobial susceptibility testing for bacteraemia in patients with haematological malignancies: a randomized controlled trial

OBJECTIVES

Recently, rapid phenotypic antimicrobial susceptibility testing (AST) based on microscopic imaging analysis has been developed. The aim of this study was to determine whether implementation of antimicrobial stewardship programmes (ASP) based on rapid phenotypic AST can increase the proportion of patients with haematological malignancies who receive optimal targeted antibiotics during early periods of bacteraemia.

METHODS

This randomized controlled trial enrolled patients with haematological malignancies and at least one positive blood culture. Patients were randomly assigned 1:1 to conventional (n = 60) or rapid phenotypic (n = 56) AST. The primary outcome was the proportion of patients receiving optimal targeted antibiotics 72 hr after blood collection for culture.

RESULTS

The percentage receiving optimal targeted antibiotics at 72 hr was significantly higher in the rapid phenotypic AST group (45/56, 80.4%) than in conventional AST group (34/60, 56.7%) (relative risk (RR) 1.42, 95% confidence interval (CI) 1.09-1.83). The percentage receiving unnecessary broad-spectrum antibiotics at 72 hr was significantly lower (7/26, 12.5% vs 18/60, 30.0%; RR 0.42, 95% CI 0.19-0.92) and the mean time to optimal targeted antibiotic treatment was significantly shorter (38.1, standard deviation (SD) 38.2 vs 72.8, SD 93.0 hr; p < 0.001) in the rapid phenotypic AST group. The mean time from blood collection to the AST result was significantly shorter in the rapid phenotypic AST group (48.3, SD 17.6 vs 83.1, SD 22.2 hr).

DISCUSSION

ASP based on rapid phenotypic AST can rapidly optimize antibiotic treatment for bacteraemia in patients with haematological malignancy. Rapid phenotypic AST can improve antimicrobial stewardship in immunocompromised patients.