scholarly journals The evolutionary history of Shigella flexneri serotype 6 in Asia

2021 ◽  
Vol 7 (12) ◽  
Author(s):  
Si-Nguyen T. Mai ◽  
Ladaporn Bodhidatta ◽  
Paul Turner ◽  
Sonam Wangchuk ◽  
Tuyen Ha Thanh ◽  
...  

Shigella flexneri serotype 6 is an understudied cause of diarrhoeal diseases in developing countries, and has been proposed as one of the major targets for vaccine development against shigellosis. Despite being named as S. flexneri , Shigella flexneri serotype 6 is phylogenetically distinct from other S. flexneri serotypes and more closely related to S. boydii . This unique phylogenetic relationship and its low sampling frequency have hampered genomic research on this pathogen. Herein, by utilizing whole genome sequencing (WGS) and analyses of Shigella flexneri serotype 6 collected from epidemiological studies (1987–2013) in four Asian countries, we revealed its population structure and evolutionary history in the region. Phylogenetic analyses supported the delineation of Asian Shigella flexneri serotype 6 into two phylogenetic groups (PG-1 and −2). Notably, temporal phylogenetic approaches showed that extant Asian S. flexneri serotype 6 could be traced back to an inferred common ancestor arising in the 18th century. The dominant lineage PG-1 likely emerged in the 1970s, which coincided with the times to most recent common ancestors (tMRCAs) inferred from other major Southeast Asian S. flexneri serotypes. Similar to other S. flexneri serotypes in the same period in Asia, genomic analyses showed that resistance to first-generation antimicrobials was widespread, while resistance to more recent first-line antimicrobials was rare. These data also showed a number of gene inactivation and gene loss events, particularly on genes related to metabolism and synthesis of cellular appendages, emphasizing the continuing role of reductive evolution in the adaptation of the pathogen to an intracellular lifestyle. Together, our findings reveal insights into the genomic evolution of the understudied Shigella flexneri serotype 6, providing a new piece in the puzzle of Shigella epidemiology and evolution.

2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 516-521 ◽  
Author(s):  
Gaiyun Zhang ◽  
Yubian Zhang ◽  
Xijie Yin ◽  
Shuang Wang

A Gram-staining-positive, aerobic, motile and non-spore-forming actinobacteria, designated strain F10T, was isolated from a deep-sea sediment of the western Pacific Ocean. Phylogenetic and phenotypic properties of the organism supported that it belonged to the genus Nesterenkonia . Strain F10T shared highest 16S rRNA gene sequence similarity of 96.8 % with Nesterenkonia aethiopica DSM 17733T, followed by Nesterenkonia xinjiangensis YIM 70097T (96.7 %) and Nesterenkonia alba CAAS 252T (96.6 %). The organism grew at 4–50 °C, at pH 7.0–12.0 and in the presence of 0–12 % (w/v) NaCl, with optimal growth occurring at 40 °C, at pH 9.0 and in the presence of 1 % (w/v) NaCl. The peptidoglycan type was A4(alpha), l-Lys–Gly–l-Glu. The polar lipid profile of strain F10T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two unknown glycolipids and two unknown lipids. The isolate contained MK-9 (92 %) and MK-8 (5.8 %) as the major components of the menaquinone system, and anteiso-C17 : 0 (50.9 %) and anteiso-C15 : 0 (29.8 %) as the predominant fatty acids. The G+C content of the genomic DNA of strain F10T was 66.2 mol%. Based on phenotypic, genotypic and phylogenetic analyses, strain F10T represents a novel species of the genus Nesterenkonia for which the name Nesterenkonia alkaliphila sp. nov. is proposed. The type strain is F10T ( = LMG 28112T = CGMCC 1.12781T = JCM 19766T = MCCC 1A09946T).


2013 ◽  
Vol 63 (Pt_3) ◽  
pp. 934-938 ◽  
Author(s):  
Wen-Ming Chen ◽  
Rey-Chang Chang ◽  
Chih-Yu Cheng ◽  
Yu-Wen Shiau ◽  
Shih-Yi Sheu

A novel bacterium, designated strain JchiT, was isolated from soil in Taiwan and characterized using a polyphasic approach. Cells of strain JchiT were aerobic, Gram-stain-negative, motile and rod-shaped. They contained poly-β-hydroxybutyrate granules and formed dark-yellow colonies. Growth occurred at 20–37 °C (optimum between 25 and 30 °C), at pH 6.0–8.0 (optimum between pH 7.0 and pH 8.0) and with 0–2 % NaCl (optimum between 0 and 1 %). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain JchiT belonged to the genus Jeongeupia and that its closest neighbour was Jeongeupia naejangsanensis BIO-TAS4-2T (98.0 % sequence similarity). The major fatty acids (>10 %) of strain JchiT were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c. The major cellular hydroxy fatty acid was C12 : 0 3-OH. The isoprenoid quinone was Q-8 and the genomic DNA G+C content was 66.1 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylserine and two unidentified phospholipids. The DNA–DNA relatedness value between strain JchiT and J. naejangsanensis BIO-TAS4-2T was about 41.0 %. On the basis of the genotypic and phenotypic data, strain JchiT represents a novel species in the genus Jeongeupia , for which the name Jeongeupia chitinilytica sp. nov. is proposed. The type strain is JchiT ( = BCRC 80367T  = KCTC 23701T).


Author(s):  
Fenfa Li ◽  
Qingyi Xie ◽  
Shuangqing Zhou ◽  
Fandong Kong ◽  
Yun Xu ◽  
...  

Strain HNM0947T, representing a novel actinobacterium, was isolated from the coral Galaxea astreata collected from the coast of Wenchang, Hainan, China. The strain was found to have morphological and chemotaxonomic characteristics consistent with the genus Nocardiopsis . The organism formed abundant fragmented substrate mycelia and aerial mycelia which differentiated into non-motile, rod-shaped spores. Whole-cell hydrolysates contained meso-diaminopimelic acid and no diagnostic sugars. The major menaquinones were MK-10(H8), MK-10(H6) and MK-10(H4). The major phospholipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides. The major fatty acids were iso-C16:0, anteiso-C17:0, C18:0, C18:0 10-methyl (TBSA) and anteiso-C15:0. The G+C content was 71.3 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain HNM0947T belonged to the genus Nocardiopsis and shared highest sequence similarity to Nocardiopsis salina YIM 90010T (98.8%), Nocardiopsis xinjiangensis YIM 90004T(98.5%) and Nocardiopsis kunsanensis DSM 44524T (98.3%). The strain HNM0947T was distinguished from its closest type strain by low average nucleotide identity (90.8%) and dDDH values (60.4%) respectively. Based on genotypic, chemotaxonomic and phenotypic characteristics, it was concluded that strain HNM0947T represents a novel species of the genus Nocardiopsis whose name was proposed as Nocardiopsis coralli sp. nov. The type strain was HNM0947T (=CCTCC AA 2020015 T=KCTC 49525 T).


Author(s):  
Shan Jiang ◽  
Feng-Bai Lian ◽  
You-Yang Sun ◽  
Xiao-Kui Zhang ◽  
Zong-Jun Du

A Gram-stain-negative, rod-shaped and facultatively aerobic bacterial strain, designated F7430T, was isolated from coastal sediment collected at Jingzi Wharf in Weihai, PR China. Cells of strain F7430T were 0.3–0.4 µm wide, 2.0–2.6 µm long, non-flagellated, non-motile and formed pale-beige colonies. Growth was observed at 4–40 °C (optimum, 30 °C), pH 6.0–9.0 (optimum, pH 7.5–8.0) and at NaCl concentrations of 1.0–10.0 % (w/v; optimum, 1.0 %). The sole respiratory quinone of strain F7430T was ubiquinone 8 and the predominant cellular fatty acids were summed feature 8 (C18 : 1  ω7c / C18 : 1  ω6c; 60.7 %), summed feature 3 (C16 : 1  ω7c/C16 : 1  ω6c; 30.2 %) and C15 : 0 iso (13.9 %). The polar lipids of strain F7430T consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified phospholipid and three unidentified lipids. Results of 16S rRNA gene sequences analyses indicated that this strain belonged to the family Halieaceae and had high sequence similarities to Parahaliea aestuarii JCM 51547T (95.3 %) and Halioglobus pacificus DSM 27932T (95.2 %) followed by 92.9–95.0 % sequence similarities to other type species within the aforementioned family. The rpoB gene sequences analyses indicated that the novel strain had the highest sequence similarities to Parahaliea aestuarii JCM 51547T (82.2 %) and Parahaliea mediterranea DSM 21924T (82.2 %) followed by 75.2–80.5 % sequence similarities to other type species within this family. Phylogenetic analyses showed that strain F7430T constituted a monophyletic branch clearly separated from the other genera of family Halieaceae . Whole-genome sequencing of strain F7430T revealed a 3.3 Mbp genome size with a DNA G+C content of 52.6 mol%. The genome encoded diverse metabolic pathways including the Entner–Doudoroff pathway, assimilatory sulphate reduction and biosynthesis of dTDP-l-rhamnose. Based on results from the current polyphasic study, strain F7430T is proposed to represent a novel species of a new genus within the family Halieaceae , for which the name Sediminihaliea albiluteola gen. nov., sp. nov. is proposed. The type strain of the type species is F7430T (=KCTC 72873T=MCCC 1H00420T).


Author(s):  
Silvio Hering ◽  
Moritz K. Jansson ◽  
Michael E. J. Buhl

A novel species within the genus Eikenella is described, based on the phenotypical, biochemical and genetic characterization of a strain of a facultatively anaerobic, Gram-negative rod-shaped bacterium. Strain S3360T was isolated from the throat swab of a patient sampled during routine care at a hospital. Phylogenetic analyses (full-length 16S rRNA gene and whole-genome sequences) placed the strain in the genus Eikenella , separate from all recognized species but with the closest relationship to Eikenella longinqua (NML 02-A-017T). Eikenella is one of the genera in the HACEK group known to be responsible for rare cases of endocarditis in humans. Until the recent descriptions of Eikenella exigua , Eikenella halliae and Eikenella longinqua , Eikenella corrodens had been the only validly published species in this genus since its description as Bacteroides corrodens in 1958. Unlike these species, strain S3360T is able to metabolize carbohydrates (glucose). The average nucleotide identities of strain S3360T with E. longinqua (NML 02-A-017T) and E. corrodens (NCTC 10596T), the type species of the genus, were 90.5 and 84.7 %, respectively, and the corresponding genome-to-genome distance values were 41.3 and 29.0 %, respectively. The DNA G+C content of strain S3360T was 58.4 mol%. Based on the phenotypical, biochemical and genetic findings, strain S3360T is considered to represent a novel species within the genus Eikenella , for which the name Eikenella glucosivorans sp. nov. is proposed. The type strain is S3360T (DSM 110714T=CCOS 1935T=CCUG 74293T). In addition, an emendation of the genus Eikenella is proposed to include species which are saccharolytic.


Author(s):  
Caixin Yang ◽  
Yibo Bai ◽  
Kui Dong ◽  
Jing Yang ◽  
Xin-He Lai ◽  
...  

Four Gram-stain-positive, catalase-negative, non-spore-forming, rod-shaped bacterial strains (zg-325T, zg329, dk561T and dk752) were isolated from the respiratory tract of marmot (Marmota himalayana) and the faeces of Tibetan gazelle (Procapra picticaudata) from the Qinghai-Tibet Plateau of PR China. The results of 16S rRNA gene sequence-based phylogenetic analyses indicated that strains zg-325T and dk561T represent members of the genus Actinomyces , most similar to Actinomyces denticolens DSM 20671T and Actinomyces ruminicola B71T, respectively. The DNA G+C contents of strains zg-325T and dk561T were 71.6 and 69.3 mol%, respectively. The digital DNA–DNA hybridization values of strains zg-325T and dk561T with their most closely related species were below the 70 % threshold for species demarcation. The four strains grew best at 35 °C in air containing 5 % CO2 on brain heart infusion (BHI) agar with 5 % sheep blood. All four strains had C18:1ω9c and C16:0 as the major cellular fatty acids. MK-8 and MK-9 were the major menaquinones in zg-325T while MK-10 was predominant in dk561T. The major polar lipids included diphosphatidylglycerol and phosphatidylinositol. On the basis of several lines of evidence from phenotypic and phylogenetic analyses, zg-325T and dk561T represent novel species of the genus Actinomyces , for which the name Actinomyces marmotae sp. nov. and Actinomyces procaprae sp. nov. are proposed. The type strains are zg-325T (=GDMCC 1.1724T=JCM 34091T) and dk561T (=CGMCC 4.7566T=JCM 33484T). We also propose, on the basis of the phylogenetic results herein, the reclassification of Actinomyces liubingyangii and Actinomyces tangfeifanii as Boudabousia liubingyangii comb. nov. and Boudabousia tangfeifanii comb. nov., respectively.


Author(s):  
So-Ra Ko ◽  
Ve Van Le ◽  
Long Jin ◽  
Sang-Ah Lee ◽  
Chi-Yong Ahn ◽  
...  

A novel Gram-stain-negative, rod-shaped, aerobic, non-motile bacterial strain, designated M5A1MT, was isolated from seawater collected from the South Sea of the Republic of Korea. Based on 16S rRNA gene sequence similarity, strain M5A1MT was closely related to Mariniflexile gromovii KMM 6038T (95.3 %), Mariniflexile fucanivorans SW5T (95.2 %), Mariniflexile soesokkakense RSSK-9T (95.1 %), Yeosuana aromativorans GW1-1T (94.6 %) and Confluentibacter lentus HJM-3T (94.6 %). Genome-based phylogenetic analyses revealed that strain M5A1MT formed a distinct cluster with the type strains of the genus Mariniflexile . The major cellular fatty acid constituents (>5 % of the total fatty acids) were iso-C15:0, anteiso-C15 : 0, iso-C15 : 0 3-OH, iso-C15 : 1 G, iso-C16:03-OH and iso-C17 : 0 3-OH. The respiratory quinone was identified as MK-6. The major polar lipids were phosphatidylethanolamine and one unidentified polar lipid. The genomic DNA G+C content of strain M5A1MT was determined to be 37.7 mol%. On the basis of its phenotypic, phylogenetic and chemotaxonomic characteristics, strain M5A1MT is considered to represent a novel species within the genus Mariniflexile , for which the name Mariniflexile maritimum sp. nov. is proposed. The type strain is M5A1MT (=KCTC 72895T=JCM 33982T).


Author(s):  
Xiunuan Chen ◽  
Bingxia Dong ◽  
Ting Chen ◽  
Na Ren ◽  
Jing Wang ◽  
...  

Aniline blue-decolourizing bacterial strain 502str22T, isolated from sediment collected in the East Pacific, was subjected to characterization by a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain 502str22T belongs to the genus Novosphingobium , with closely related type strains ‘ Novosphingobium profundi ’ F72T (97.6%), N. mathurense SM117T (97.1%) and N. arvoryzae Jyi-02T (97.0%). Digital DNA–DNA hybridization and average nucleotide identity values between strain 502str22T and closely related type strains were 20.3–24.8% and 74.1–81.9%, respectively. The major cellular fatty acid (>10%) was C18:1 ω7c. The polar lipid profile consisted of a mixture of phosphatidylcholine, one sphingoglycolipid, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylmonomethylethanolamine. The DNA G+C content of strain 502str22T was 65.5 mol%. The polyphasic taxonomic results indicated that strain 502str22T represents a novel species of the genus Novosphingobium , for which the name Novosphingobium decolorationis sp. nov is proposed. The type strain is 502str22T (=KCTC 82134T= MCCC 1K04799 T).


2012 ◽  
Vol 62 (Pt_9) ◽  
pp. 2163-2168 ◽  
Author(s):  
Yong-Taek Jung ◽  
Ji-Hoon Kim ◽  
So-Jung Kang ◽  
Tae-Kwang Oh ◽  
Jung-Hoon Yoon

A Gram-staining-negative, non-flagellated, non-gliding and pleomorphic bacterial strain, designated DPG-25T, was isolated from seawater in a seaweed farm in the South Sea in Korea and its taxonomic position was investigated by using a polyphasic approach. Strain DPG-25T grew optimally at 25 °C, at pH 7.0–7.5 and in the presence of 2 % (w/v) NaCl. Flexirubin-type pigments were not produced. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain DPG-25T formed a cluster with the type strains of Actibacter sediminis , Aestuariicola saemankumensis and Lutimonas vermicola . Strain DPG-25T exhibited 16S rRNA gene sequence similarity values of 95.3, 93.1 and 93.6 % to the type strains of Actibacter sediminis , Aestuariicola saemankumensis and L. vermicola , respectively. Strain DPG-25T contained MK-6 as the predominant menaquinone and iso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids. The major polar lipids detected in strain DPG-25T were phosphatidylethanolamine and one unidentified lipid. The DNA G+C content was 39.9 mol%. Differential phenotypic properties and the phylogenetic distinctiveness of strain DPG-25T demonstrated that this strain is distinguishable from Actibacter sediminis , Aestuariicola saemankumensis and L. vermicola . On the basis of the data presented here, strain DPG-25T represents a novel species in a novel genus of the family Flavobacteriaceae , for which the name Namhaeicola litoreus gen. nov., sp. nov. is proposed. The type strain of Namhaeicola litoreus is DPG-25T ( = KCTC 23702T  = CCUG 61485T).


2015 ◽  
Vol 65 (Pt_4) ◽  
pp. 1207-1212 ◽  
Author(s):  
Hong-Fei Wang ◽  
Yong-Guang Zhang ◽  
Ji-Yue Chen ◽  
Jian-Wei Guo ◽  
Li Li ◽  
...  

A novel endophytic actinobacterium, designated EGI 6500707T, was isolated from the surface-sterilized root of a halophyte Anabasis elatior (C. A. Mey.) Schischk collected from Urumqi, Xinjiang province, north-west China, and characterized using a polyphasic approach. Cells were Gram-stain-positive, non-motile, short rods and produced white colonies. Growth occurred at 10–45 °C (optimum 25–30 °C), at pH 5–10 (optimum pH 8) and in presence of 0–4 % (w/v) NaCl (optimum 0–3 %). The predominant menaquinone was MK-9. The diagnostic phospholipids were diphosphatidylglycerol and phosphatidylglycerol. The major fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The DNA G+C content of strain EGI 6500707T was 69.1 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain EGI 6500707T should be placed in the genus Frigoribacterium (family Microbacteriaceae , phylum Actinobacteria ), and that the novel strain exhibited the highest 16S rRNA gene sequence similarity to Frigoribacterium faeni JCM 11265T (99.1 %) and Frigoribacterium mesophilum MSL-08T (96.5 %). DNA–DNA relatedness between strain EGI 6500707T and F. faeni JCM 11265T was 47.2 %. On the basis of phenotypic and chemotaxonomic characteristics, phylogenetic analysis and DNA–DNA relatedness data, strain EGI 6500707T represents a novel species of the genus Frigoribacterium , for which the name Frigoribacterium endophyticum sp. nov. is proposed. The type strain is EGI 6500707T ( = JCM 30093T = KCTC 29493T).


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