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Background Validation and standardization of methodologies for microbial community measurements by high-throughput sequencing are needed to support human microbiome research and its industrialization. This study set out to establish standards-based solutions to improve the accuracy and reproducibility of metagenomics-based microbiome profiling of human fecal samples. Results In the first phase, we performed a head-to-head comparison of a wide range of protocols for DNA extraction and sequencing library construction using defined mock communities, to identify performant protocols and pinpoint sources of inaccuracy in quantification. In the second phase, we validated performant protocols with respect to their variability of measurement results within a single laboratory (that is, intermediate precision) as well as interlaboratory transferability and reproducibility through an industry-based collaborative study. We further ascertained the performance of our recommended protocols in the context of a community-wide interlaboratory study (that is, the MOSAIC Standards Challenge). Finally, we defined performance metrics to provide best practice guidance for improving measurement consistency across methods and laboratories. Conclusions The validated protocols and methodological guidance for DNA extraction and library construction provided in this study expand current best practices for metagenomic analyses of human fecal microbiota. Uptake of our protocols and guidelines will improve the accuracy and comparability of metagenomics-based studies of the human microbiome, thereby facilitating development and commercialization of human microbiome-based products.

We report the complete genome sequence of Flavonifractor plautii JCM 32125T (=VPI 0310T). The genome consists of a single circular chromosome of 3,985,392 bp (G+C content, 60.9%) and was predicted to contain 3 complete sets of rRNA genes, 63 tRNA genes, and 3,764 protein-coding sequences.

We report a complete genome sequence of Collinsella aerofaciens JCM 10188T (=VPI 1003T). The genome consists of a circular chromosome (2,428,218 bp with 60.6% G+C content) and two extrachromosomal elements. The genome was predicted to contain 5 sets of rRNA genes, 58 tRNA genes, and 2,079 protein-encoding sequences.

We announce the complete genome sequence of Megamonas funiformis JCM 14723T (YIT 11815T). The genome consists of a circular chromosome (2,522,577 bp, 31.5% G+C content) and a plasmid of 46,189 bp (29.4% G+C content). The genome was predicted to contain 6 rRNA operons, 53 tRNA genes, and 2,440 protein-coding sequences.

We report a complete genome sequence of Blautia producta JCM 1471T. The genome consists of a single circular chromosome of 6,197,116 bp with a G+C content of 45.7%. The genome was annotated as containing 5 complete sets of rRNA genes, 70 tRNA genes, and 5,516 protein-coding sequences.

We investigated the effects of dasatinib on natural killer (NK) cell-induced signaling protein and perforin expression as well as plasma cytokine levels by analyzing blood samples from patients with well-controlled chronic myeloid leukemia receiving tyrosine kinase inhibitor (TKI) therapy. Perforin expression and phosphorylation of signal transducer and activator of transcription (STAT) 1, STAT3, Janus kinase (JAK) 1, and JAK2 in NK cells were evaluated by flow cytometry, and the levels of plasma cytokines, including interferon (IFN)-γ and interleukin (IL)-2, were determined by enzyme-linked immunosorbent assays in 40 patients (dasatinib, n = 23; imatinib, n = 11; and nilotinib, n = 6). Perforin levels in NK cells were higher in dasatinib-treated patients before TKI treatment; phospho (p)-STAT1 levels were closely correlated with pJAK1 and perforin levels, and pSTAT3 levels were correlated with pJAK2 and perforin levels. The correlation between pJAK1 and pSTAT1 was apparent in dasatinib-treated patients but not in other TKI-treated patients, and the correlation between pJAK2 and pSTAT3 was apparent in patients treated with other TKIs. Constitutive expression of IFN-γ was higher in patients treated with dasatinib or with other TKIs than in those who were in treatment-free remission (TFR). In contrast, constitutive expression of IL-2 was lower in patients treated with other TKIs than in those treated with dasatinib or in those who were in TFR. These results provided insights into the effects of dasatinib on JAK/STAT signaling in NK cells in vivo and the mechanisms underlying NK cell activation induced by dasatinib therapy.

We report the case of a 53-year-old male with a history of acute myelogenous leukemia, who suffered the rupturing of a right-sided pulmonary artery pseudoaneurysm combined with pneumonia. He underwent a right-sided lower lobectomy. The resected lung tissue demonstrated a mycotic pseudoaneurysm of a pulmonary artery branch together with a filamentous fungal infection. Pseudoaneurysms are caused by the breaching of all layers of a blood vessel wall. The extravasated blood is trapped by the surrounding extravascular tissue or clots. Cladosporium was detected during a polymerase chain reaction-based analysis followed by DNA sequencing of formalin-fixed paraffin-embedded lung tissue samples. Although previous cases of pulmonary artery pseudoaneurysms caused by fungal infections, e.g., Candida or Aspergillus sp., have been reported, to the best of our knowledge this is the first case to involve cladosporiosis.

Mantle cell lymphoma (MCL) is a B cell neoplasm characterized by cyclin D1 overexpression; its prognosis is poor, especially when it exhibits a blastoid morphology. Cyclin D1-negative MCL is rare, and its pathogenesis and progression remain unclear. Herein, we describe a cyclin D1-negative, cyclin D2-positive MCL with a CCND2 and immunoglobulin lambda light chain (IGL) translocation. The patient was initially diagnosed with cyclin D1-negative MCL and achieved complete remission via combination chemotherapy and autologous stem cell transplantation. After relapsing, he was diagnosed with a blastoid variant of MCL that showed lymphoid cells with dispersed chromatin and more mitotic figures and higher p53 expression compared with the initial MCL. Despite salvage therapies, the disease became refractory, and the patient died 28 months after initiating chemotherapy. This case demonstrates that blastoid morphology in cyclin D1-negative MCL with IGL-CCND2 translocation indicates progression to a more aggressive neoplasm, similar to cyclin D1-positive MCL.

We have developed and characterized a bacterial consortium that reductively dechlorinates trichloroethene to ethene. Quantitative PCR analysis for the 16S rRNA and reductive dehalogenase genes showed that the consortium is highly enriched with Dehalococcoides spp. that have two vinyl chloride reductive dehalogenase genes, bvcA and vcrA, and a trichloroethene reductive dehalogenase gene, tceA. The metagenome analysis of the consortium by the next generation sequencer SOLiD 3 Plus suggests that a Dehalococcoides sp. that is highly homologous to D. mccartyi 195 and equipped with vcrA and tceA exists in the consortium. We isolated this Dehalococcoides sp. and designated it as D. mccartyi UCH-ATV1. As the growth of D. mccartyi UCH-ATV1 is too slow under isolated conditions, we constructed a consortium by mixing D. mccartyi UCH-ATV1 with several other bacteria and performed metagenomic sequencing using the single molecule DNA sequencer PacBio RS II. We successfully determined the complete genome sequence of D. mccartyi UCH-ATV1. The strain is equipped with vcrA and tceA, but lacks bvcA. Comparison with tag sequences of SOLiD 3 Plus from the original consortium shows a few differences between the sequences. This suggests that a genome rearrangement of Dehalococcoides sp. occurred during culture.

Here, we report the draft genome sequence of Thermogemmatispora onikobensis NBRC 111776 T , an aerial mycelium- and spore-forming thermophilic bacterium belonging to the class Ktedonobacteria . The genome contains five biosynthetic gene clusters coding for secondary metabolites, such as terpene, thiopeptide, lantipeptide, nonribosomal peptide, and lassopeptide, suggesting the potential to produce secondary metabolites.

Background : In myeloproliferative neoplasms, especially essential thrombocythemia (ET), platelet (Plt) counts and von Willebrand factor (vWF):Ristocetin cofactor (RCo) levels have been reported to be inversely correlated. However, there have been no reports of the comparison of high vs. low values of JAK2 allele burden and necessary of Plt counts reduction to achieve vWF:RCo levels ≥50%, which is required for major surgery. We investigated the correlation between vWF level and Plt counts for JAK2V617F mutation positive (JAK2V617F+) polycythemia vera (PV) and ET (allele burdens ≥50% and Method: We recruited patients with PV and ET who were diagnosed per the 2008 World Health Organization criteria at 3 hospitals since 2011 to 2018. All patients were analyzed at Juntendo University for JAK2 (V617F, exson12), CALR, and MPL mutations. We collected data of JAK2V617F+ or CALR+ patients. Triple-negative mutations of ET were excluded in this study because it is difficult to differentiate between ET and secondary thrombocytosis. We analyzed the correlation between Plt counts and vWF:RCo levels for three mutation groups mutations (JAK2V617F allele burden ≥50%, Results: We collected 146 PV and ET patients. Among 54 PV patients, 50 had JAK2V617F+, 3 had JAK2 exon 12, and 1 had a triple-negative mutation(s) in PV patients. Among 92 ET patients, 53 had JAK2V617F+, 35 had CALR+ (22 del52, 12 ins5 and 1 del34), and 4 had MPL mutations in ET patients. vWF:RCo levels were weakly inversely correlated with Plt counts in patients with JAK2V617F+ PV and ET from whom blood samples were obtained for the first time after enrolling in this study (Ps=-0.531 and Ps=-0.439, respectively). In contrast, vWF:RCo levels and Plt counts in patients with CALR+ ET showed a strong inverse correlation (Ps=-0.762). Interestingly, 3/50 PV and 4/53 ET patients with JAK2V617F mutations showed vWF:RCo levels >150% (normal vWF:RCo levels range: 50-150%). Furthermore, 3/50 PV and 1/53 ET patients with Plt counts 150% or During the entire observation period, 8/50 and 7/53 patients with JAK2V617F+ PV and ET, respectively, and 1/35 patients with CALR+ ET had vWF:RCo levels >150%. One case of JAK2V617F+ ET (allele burden When Plt counts were controlled to 30%. However, 13/86 patients did not achieve 50%, which is the standard for safely performing the major surgical procedures prescribed in most guidelines. In patients whose Plt counts controlled to Conclusion: For patients with CALR+ ET, we propose that vWF:RCo levels can be predicted based on Plt counts; however, it is difficult to predict vWF:RCo levels by Plt counts in JAK2V617F+ PV and ET patients because the inverse correlation between vWF:RCo levels and Plt counts was weak. Overactivation of vWF:RCo levels was often observed in JAK2+ PV and ET. Moreover, in 1 case, the patient exhibited only age as the risk factor for the complication of thrombosis. Because of these findings, overactivation of vWF:RCo levels may be one of the reasons for thrombotic events in JAK2V617F+ PV and ET. In addition, it was also found that cases of JAK2V617F+ allele burden ≥50% in PV and ET should be careful for hemorrhage in major surgery, even if Plt counts were controlled Disclosures No relevant conflicts of interest to declare.

The taxonomic properties of strain DC2a-G7T, a Gram-negative, ovoid to rod-shaped, gellan gum-lysing bacterium, were examined. The 16S rRNA gene sequence similarity showed that DC2a-G7T is a member of the phylum Verrucomicrobia and the closest type strain of a species with a validly published name is Verrucomicrobium spinosum DSM 4136T, with a sequence similarity of 91.2 %. In addition to this similarity value lower than 95 %, the absence of prostheca, the orangey-red colony colour and the compositions of the major menaquinones and polar lipids also supported the differentiation of this bacterium from the genus Verrucomicrobium . Here, we propose the name Roseimicrobium gellanilyticum gen. nov., sp. nov. for the isolate. The type strain of Roseimicrobium gellanilyticum is DC2a-G7T ( = NBRC 108606T = DSM 25532T).

A thermotolerant ammonia-oxidizing bacterium strain JPCCT2 was isolated from activated sludge in a thermal power station. Cells of JPCCT2 are short non-motile rods or ellipsoidal. Molecular phylogenetic analysis of 16S rRNA gene sequences demonstrated that JPCCT2 belongs to the genus Nitrosomonas with the highest similarity to Nitrosomonas nitrosa Nm90 (100%), Nitrosomonas sp. Nm148 (99.7%), and Nitrosomonas communis Nm2 (97.7%). However, G+C content of JPCCT2 DNA was 49.1 mol% and clearly different from N. nitrosa Nm90, 47.9%. JPCCT2 was capable of growing at temperatures up to 48 °C, while N. nitrosa Nm90 and N. communis Nm2 could not grow at 42°C. Moreover, JPCCT2 grew similarly at concentrations of carbonate 0 and 5 gL(-1). This is the first report that Nitrosomonas bacterium is capable of growing at temperatures higher than 37°C.

In this study, the impact of plasma cell maturity on the prognoses of multiple myeloma (MM) patients in the era of novel agents was investigated. Myeloma cell maturity was classified via immunophenotyping: myeloma cells showing mature plasma cell 1 (MPC-1)-positive and CD49e-positive cells were considered mature type; MPC-1-positive and CD49e-negative cells were considered intermediate type; and MPC-1-negative cells were considered immature type. This study included 87 newly diagnosed MM patients who were initially treated with bortezomib and/or chemotherapy. Myeloma cell maturity was a critical factor affecting overall survival (OS) in the cohort, with median OS not reached in mature-type, 50 months in intermediate-type, and 20 months in immature-type cells. Multivariate analysis showed that immature type and stage III according to the International Staging System were both independent prognostic factors affecting OS. The findings of this study demonstrate the clinical importance of myeloma cell classification according to immunophenotyping using MPC-1 and CD49e antibodies to determine patient prognosis in this era of novel therapeutic agents.

The published sequence of the 16S rRNA gene of Thiomonas cuprina strain Hö5 (=DSM 5495T) (GenBank accession no. U67162) was found to be erroneous. The 16S rRNA genes from the type strain held by the DSMZ since 1990 (DSM 5495T =NBRC 102145T) and strain Hö5 maintained frozen in the Universität Regensburg for 23 years (=NBRC 102094) were sequenced and found to be identical, but to show no significant similarity to the U67162 sequence. This also casts some doubt on the previously published 5S and 23S rRNA gene sequences (GenBank accession nos U67171 and X75567). The correct 16S rRNA gene sequence showed 99.8 % identity to those from Thiomonas delicata NBRC 14566T and ‘Thiomonas arsenivorans’ DSM 16361. The properties of these three species are re-evaluated, and emended descriptions are provided for the genus Thiomonas and the species Thiomonas cuprina.

The taxonomic positions of two bacterial strains, MBIC01146(T) and MBIC01099, isolated from marine environments of Japan and Palau, respectively, were determined by using a polyphasic approach. The bacteria were aerobic, motile, Gram-negative rods and formed star-shaped aggregations. The G+C content of the genomic DNA ranged from 58.5 to 58.7 mol%. The major respiratory quinone was ubiquinone-10 and the predominant cellular fatty acids were C(16 : 0), C(18 : 1)omega6c and C(18 : 1)omega7c. 16S rRNA gene sequence analyses based on both neighbour-joining and maximum-parsimony methods revealed that strains MBIC01146(T) and MBIC01099 were positioned within the cluster comprising Ruegeria atlantica and Silicibacter lacuscaerulensis within subgroup alpha-3 of the Proteobacteria. The phenotypic and chemotaxonomic characteristics of the novel strains were similar to those of Ruegeria atlantica; however, DNA-DNA hybridization tests showed that the isolates represented an independent species. The isolates could be differentiated from Ruegeria atlantica based on several characteristics. Therefore, strains MBIC01146(T) and MBIC01099 are considered to represent a novel species of the genus Ruegeria, for which the name Ruegeria mobilis sp. nov. is proposed. The type strain is MBIC01146(T) (=NBRC 101030(T)=CIP 109181(T)). An emended description of Ruegeria atlantica Uchino et al. 1999 is also given.

Sulfurospirillum strains UCH001 and UCH003 were isolated from anaerobic cis -1,2-dichloroethene-dechlorinating microbial consortia derived from groundwater in Japan. Here, we report the complete genome sequences of strains UCH001 and UCH003.

The transfer of Thiobacillus delicatus to the genus Thiomonas as a distinct species, Thiomonas delicata (type strain NBRC 14566T), is confirmed by its morphological and physiological properties, DNA–DNA hybridization and the grouping of its 16S rRNA gene sequence with those of other species of the genus. An emended formal description of Thiomonas delicata is given. The status of Thiomonas cuprina DSM 5495T as a member of the genus is reconsidered.

A novel Gram-stain positive, non-motile, non-sporeforming coccus-shaped, obligately anaerobic bacterium was isolated from a fecal sample of an individual residing in a traditional Peruvian community. The organism was characterized using biochemical, chemotaxonomic and phylogenetic methods. Comparative 16S rRNA gene sequence analyses and phenotypic characteristics demonstrated that the organism was biochemically and phenotypically related, but distinct, from a group of organisms referred to as the Gram-stain positive anaerobic cocci (GPAC). The major cellular fatty acids of the novel isolate were determined to be C 16:0 (18.3%), C 18:1 ω 9c (39.8%), C 18:2 ω 6,9c /C 18:0 ANTE (13.2%). Fermentation end products from PYG are acetate and formate. Cell-wall peptidoglycan was found to be A4α (L-Lys-L-Ala-L-Glu) and the G + C content was determined to be 38.4 mol%. Based on the phenotypic, chemotaxonomic, and phylogenetic results, Ezakiella peruensis gen. nov., sp. nov., is now proposed. The type strain is M6.X2 T (DSM 27367 T = NBRC 109957 T = CCUG 64571 T ).

The bootstrapped 16S rDNA sequence-based neighbor-joining phylogeny has suggested that the marine species of the genus Agrobacterium have no relation to the terrestrial Agrobacterium species. Agrobacterium atlanticum IAM 14463(T) (a superscript (T)=type strain), Agrobacterium ferrugineum IAM 12616(T), Agrobacterium gelatinovorum IAM 12617(T), Agrobacterium meteori IAM 14464(T), Agrobacterium stellulatum IAM 12621(T) and IAM 12614, and the invalidly published marine species "Agrobacterium kieliense" IAM 12618 occupy an independent position in the a-subclass of the Proteobacteria. Based on 16S rDNA sequencing and on chemotaxonomic, morphological, and physiological studies, we propose the transfer of A. atlanticum, A. gelatinovorum, and Roseobacter algicola to the genus Ruegeria gen. nov. as Ruegeria atlantica comb. nov., Ruegeria gelatinovora comb. nov., and Ruegeria algicola comb. nov., respectively; of strains of A. stellulatum to the genus Stappia gen. nov. as Stappia stellulata comb. nov. and Stappia aggregata sp. nov., nom. rev., respectively; and of "A. kieliense" to the genus Ahrensia gen. nov. as Ahrensia kieliense sp. nov., nom. rev. Agrobacterium meteori is assigned to be a synonym of A. atlanticum.

Objective Bacillus cereus (B. cereus) septicemia is a cause of life-threatening infection in patients with hematologic diseases. However, preventing a fatal prognosis in patients with B. cereus infection has not yet been achieved due to insufficient clinical investigations. To discover more optimal treatment strategies, we analyzed B. cereus septicemia in patients with hematologic diseases. Methods At our institution, we observed 13 cases of B. cereus septicemia in 12 patients with hematologic diseases between January 2001 and September 2010. The susceptibility of B. cereus strains to antibiotics was also analyzed. Results Of 12 patients, four died of B. cereus septicemia. In this study, the delayed administration of appropriate antibiotics (starting >24 hours after presentation), the presence of liver dysfunction and evidence of central nervous system (CNS) involvement tended to result in a fatal prognosis. All of the bacterial strains were found to be susceptible to vancomycin and quinolones (such as ciprofloxacin and levofloxacin), whereas many strains were resistant to clindamycin (76.9%) and imipenem (30.8%). In seven of 10 patients, central venous (CV) catheter tips were removed and routinely cultured. Catheter tip cultures were positive for B. cereus in three of seven patients. Conclusion Although not specific to B. cereus bacteremia, patients who died of B. cereus tended to present with CNS symptoms and/or liver dysfunction. Our clinical data suggested that carbapenem and clindamycin are no longer appropriate choices for treating B. cereus. In addition, B. cereus septicemia was found to frequently originate from CV catheters. Constant attention must be paid to update assessments of antibiotic susceptibility and careful management must be applied to CV catheters in patients with hematologic diseases.

The 16S rRNA gene sequences of 12 strains of Thiobacillus thioparus held by different culture collections have been compared. A definitive sequence for the reference type strain (Starkey; ATCC 8158(T)) was obtained. The sequences for four examples of the Starkey type strain were essentially identical, confirming their sustained identity after passage through different laboratories. One strain (NCIMB 8454) was reassigned as a strain of Halothiobacillus neapolitanus, and a second (NCIMB 8349) was a species of Thermithiobacillus. These two strains have been renamed in their catalog by the National Collection of Industrial and Marine Bacteria. The 16S rRNA gene sequence of the type strain of Halothiobacillus neapolitanus (NCIMB 8539(T)) was determined and used to confirm the identity of other culture collection strains of this species. The reference sequences for the type strains of Thiobacillus thioparus and Halothiobacillus neapolitanus have been added to the online List of Prokaryotic Names with Standing in Nomenclature. Comparison of the 16S rRNA gene sequences available for strains of Thiobacillus denitrificans indicated that the sequence for the type strain (NCIMB 9548(T)) should always be used as the reference sequence for new and existing isolates.

A moderately thermophilic chemoheterotrophic bacterium, strain Mat9-16T, was isolated from microbial mats developed in hot spring water streams from Yumata, Nagano, Japan. Cells of strain Mat9-16Twere strictly anaerobic, Gram-stain-negative, non-sporulating, non-motile and short to long rods (2.0–15.5 μm in length). Strain Mat9-16Tgrew fermentatively with optimum growth at 45 °C, pH 7.0–7.5 and 1 % NaCl (w/v). Phylogenetic analysis based on the 16S rRNA gene revealed that strain Mat9-16Twas affiliated with an uncultivated lineage, and the nearest cultivated neighbours were green sulfur bacteria belonging to the classChlorobeawith 77–83 % sequence similarity. However, strain Mat9-16Tcould not grow phototrophically and did not possess light-harvesting structures, morphologically and genetically, such as the chlorosomes of green sulfur bacteria. On the basis of phenotypic features and phylogenetic position, a novel genus and species are proposed for strain Mat9-16T, to be namedIgnavibacterium albumgen. nov., sp. nov. (=NBRC 101810T=DSM 19864T). We also propose to place the cultivated bacterial lineage accommodating the sole representative Mat9-16Tin a novel class,Ignavibacteriaclassis nov. In addition, we present a formal description of the phylum-level taxon‘Chlorobi’asChlorobiphyl. nov.

The marine gram-negative non-photosynthetic bacterium, Agrobacterium ferrugineum IAM 12616(T) forms one cluster with the species of the photosynthetic genus Rhodobacter in phylogenetic trees based on molecules of 16S rRNA, 23S rRNA and DNA gyrases. Agrobacterium ferrugineum and Rhodobacter species are similar in that growth occurs without NaCl in the culture medium (optimal NaCl concentration for growth of P. ferrugineus is 1%) and their major hydroxy fatty acid compositions are 3-hydroxy decanoic acids (3-OH 10:0) and 3-hydroxy tetradecanoic acids (3-OH 14:1). However, A. ferrugineum differs from Rhodobacter species in G+C content (58 mol% in A. ferrugineum versus 64-73 mol% in Rhodobacter species), in having an insertion in its 16S rRNA gene sequence, and in lacking photosynthetic abilities, bacteriochlorophyll a and intracytoplasmic membrane systems. Furthermore, experiments using PCR and Southern hybridization show that A. ferrugineum does not have puhA gene and puf genes localized near the opposite ends of the photosynthesis gene cluster of Rhodobacter capsulatus. It suggests that A. ferrugineum may not have any genes for photosynthesis. We propose the transfer of A. ferrugineum IAM 12616(T) to the genus Pseudorhodobacter gen. nov. as Pseudorhodobacter ferrugineus comb. nov. Although Pseudorhodobacter ferrugineus disturbs the phylogenetic monophyly of the genus Rhodobacter, this taxonomic proposal seems adequate until it has been clarified whether P. ferrugineus possesses an incomplete photosynthetic apparatus.

We found that Rhodobacter azotoformans IFO 16436T contains two different cbbL genes coding form I ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) large subunits. One gene is located within a "green-like" group of the RubisCO phylogenetic tree, and the other is located within a "red-like" group. This is the first report that one organism contains both green-like and red-like RubisCO genes. Moreover, by PCR using primers which amplify two green-like and red-like cbbL genes alternatively and dot blot hybridization, we demonstrated that Rhodobacter blasticus, Rhodobacter capsulatus, and Rhodobacter veldkampii possess only green-like cbbL genes, and Rhodobacter sphaeroides possesses only a red-like cbbL gene. In the cbbL phylogenic analysis, R. spaeroides and R. azotoformans 1 (red-like) formed a cluster within the red-like group, and R. capsulatus, R. azotoformans 2 (green-like), R. blasticus, and R. veldkampii formed a cluster within the green-like group. This suggests that red-like cbbL genes of Rhodobacter species were derived from one ancestor, and green-like cbbL genes were derived from another ancestor. On the other hand, molecular phylogeny of the bacteria indicates that R. veldkampii, which has only a green-like cbbL gene, is the earliest evolved Rhodobacter species and that R. azotoformans and R. sphaeroides, which have red-like cbbL genes, are the latest evolved. Consequently, the following hypothesis is proposed: the common ancestor of Rhodobacter had a green-like cbbL gene, the common ancestor of R. azotoformans and R. sphaeroides subsequently obtained a red-like cbbL gene by a horizontal gene transfer, and the ancestor of R. sphaeroides later lost the green-like cbbL gene.

To the editor,Eradication of Helicobacter pylori (H. pylori) is one of the useful treatments of H. pylori-positive chronic immune thrombocytopenic purpura (ITP) [1, 2], and considered as a first-li...