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1.
Article in English | MEDLINE | ID: mdl-38722771

ABSTRACT

Obligately anaerobic, Gram-stain-negative, wavy rods, strains 17YCFAHCo10, 18YCFAH0.3Co2 and 19YCFAH0.3Co2, were isolated from faecal samples of healthy Japanese people. The three isolates showed the highest 16S rRNA gene sequence similarity to Waltera intestinalis WCA3-601-WT-6HT (99.2-100 %) and Brotolimicola acetigignens f_CXYT (99.2-99.7 %). The 16S rRNA gene sequence analysis showed that the three isolates formed a cluster with W. intestinalis WCA3-601-WT-6HT. Strain 19YCFAH0.3Co2 formed a subcluster with the type strain of W. intestinalis and did not form a cluster with the other two isolates. B. acetigignens f_CXYT also formed a cluster with W. intestinalis WCA3-601-WT-6HT and three isolates. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain 19YCFAH0.3Co2 and W. intestinalis WCA3-601-WT-6HT were higher (72 % dDDH and 97 % ANI) than the cut-off values for species delimitation, indicating that strain 19YCFAH0.3Co2 is W. intestinalis. On the other hand, the dDDH and ANI values between strains 17YCFAHCo10 and 18YCFAH0.3Co2 and the type strain of W. intestinalis were lower (<34 % dDDH and <87 % ANI) than the cut-off values for species delimitation, indicating that these two isolates are different species from W. intestinalis. The percentage of conserved proteins and the average amino acid identity values support the assignment of the isolates to the genus Waltera. Strains 17YCFAHCo10 and 18YCFAH0.3Co2 could be distinguished from W. intestinalis by their inability to ferment melibiose and ribose and lack of activity for ß-glucuronidase. In addition, the dDDH and ANI values between two strains (17YCFAHCo10 and 18YCFAH0.3Co2) and B. acetigignens f_CXYT were higher (>78 % dDDH and >97 % ANI), indicating these two strains and B. acetigignens are the same species. As the genus Waltera has priority, B. acetigignens is transferred to the genus Waltera as Waltera acetigignens comb. nov. The type strain of W. acetigignens is f_CXYT (=JCM 34988T=DSM 107528T).


Subject(s)
Bacterial Typing Techniques , DNA, Bacterial , Feces , Nucleic Acid Hybridization , Phylogeny , RNA, Ribosomal, 16S , Sequence Analysis, DNA , RNA, Ribosomal, 16S/genetics , Feces/microbiology , DNA, Bacterial/genetics , Japan , Humans , Fatty Acids/chemistry , Base Composition
2.
Nat Commun ; 14(1): 7232, 2023 11 14.
Article in English | MEDLINE | ID: mdl-37963895

ABSTRACT

It is generally assumed that all bacteria must have at least one rRNA operon (rrn operon) on the chromosome, but some strains of the genera Aureimonas and Oecophyllibacter carry their sole rrn operon on a plasmid. However, other related strains and species have chromosomal rrn loci, suggesting that the exclusive presence of rrn operons on a plasmid is rare and unlikely to be stably maintained over long evolutionary periods. Here, we report the results of a systematic search for additional bacteria without chromosomal rrn operons. We find that at least four bacterial clades in the phyla Bacteroidota, Spirochaetota, and Pseudomonadota (Proteobacteria) lost chromosomal rrn operons independently. Remarkably, Persicobacteraceae have apparently maintained this peculiar genome organization for hundreds of millions of years. In our study, all the rrn-carrying plasmids in bacteria lacking chromosomal rrn loci possess replication initiator genes of the Rep_3 family. Furthermore, the lack of chromosomal rrn operons is associated with differences in copy numbers of rrn operons, plasmids, and chromosomal tRNA genes. Thus, our findings indicate that the absence of rrn loci in bacterial chromosomes can be stably maintained over long evolutionary periods.


Subject(s)
Operon , rRNA Operon , rRNA Operon/genetics , Plasmids/genetics , Operon/genetics , Chromosomes , Bacteria/genetics , RNA, Ribosomal/genetics
3.
Microbiol Resour Announc ; 12(11): e0063223, 2023 Nov 16.
Article in English | MEDLINE | ID: mdl-37800929

ABSTRACT

Here, we report the complete genome sequences of two Ruminococcus torques strains (JCM 36208 and JCM 36209) that were newly isolated from the feces of a healthy Japanese male. Both genomes consist of a single circular chromosome with a length of ~2.8 Mbp and a G+C content of 41.8%.

4.
Article in English | MEDLINE | ID: mdl-37737068

ABSTRACT

Obligately anaerobic, Gram-stain-positive, bacilli, strains 12BBH14T, 9CFEGH4 and 10CPCBH12, were isolated from faecal samples of healthy Japanese people. Strain 12BBH14T showed the highest 16S rRNA gene sequence similarity to Sellimonas monacensis Cla-CZ-80T (97.5 %) and 'Lachnoclostridium phocaeense' Marseille-P3177T (97.2 %). Strain 12BBH14T was also closely related to Eubacterium sp. c-25 with 99.7 % 16S rRNA gene sequence similarity. The 16S rRNA gene sequence analysis showed that strains 12BBH14T, 9CFEGH4 and 10CPCBH12 formed a monophyletic cluster with Eubacterium sp. c-25. Near this monophyletic cluster, S. monacensis Cla-CZ-80T and 'L. phocaeense' Marseille-P3177T formed a cluster and did not form a cluster with other Sellimonas species. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strains 12BBH14T, 9CFEGH4, 10CPCBH12 and Eubacterium sp. c-25 were higher than the cut-off values of species demarcation (>88 % dDDH and >98 % ANI), indicating that these four strains are the same species. On the other hand, the dDDH and ANI values of these strains were lower than the cut-off values of species demarcation against other strains (<29 % dDDH and <76 % ANI). Moreover, the average amino acid identity values among these strains were higher than the genus boundary. These results indicate that the isolates should be considered to belong to a new genus of the family Lachnospiraceae. Based on the collected data, strains 12BBH14T, 9CFEGH4 and 10CPCBH12 represent a novel species of a novel genus, for which the name Claveliimonas bilis gen. nov., sp. nov. is proposed. The type strain of C. bilis is 12BBH14T (=JCM 35899T=DSM 115701T). Eubacterium sp. c-25 belongs to C. bilis. In addition, S. monacensis is transferred to the genus Claveliimonas as Claveliimonas monacensis comb. nov.


Subject(s)
Bacteria , Fatty Acids , Humans , RNA, Ribosomal, 16S/genetics , Phylogeny , Sequence Analysis, DNA , DNA, Bacterial/genetics , Bacterial Typing Techniques , Base Composition , Fatty Acids/chemistry , Feces , Nucleotides , Deoxycholic Acid
5.
Article in English | MEDLINE | ID: mdl-37566461

ABSTRACT

A strain of the recently validated species Faecalibacterium hominis shares 99.0 % 16S rRNA gene sequence similarity with the type strain of Faecalibacterium duncaniae. The aim of this study was to evaluate the taxonomic relationship between F. hominis and F. duncaniae. F. duncaniae JCM 31915T showed 73.0 % digital DNA-DNA hybridization (dDDH) value with F. hominis JCM 39347T. The average nucleotide identity (ANI) value between these two strains was 96.7 %. These results indicate that F. duncaniae JCM 31915T and F. hominis JCM 39347T represent members of the same species. Based on these data, we propose Faecalibacterium hominis as a later heterotypic synonym of Faecalibacterium duncaniae. An emended description is provided.


Subject(s)
Fatty Acids , Sequence Analysis, DNA , Fatty Acids/chemistry , RNA, Ribosomal, 16S/genetics , Bacterial Typing Techniques , Phylogeny , DNA, Bacterial/genetics , Base Composition , Nucleic Acid Hybridization
6.
Microbiol Spectr ; 11(4): e0078223, 2023 08 17.
Article in English | MEDLINE | ID: mdl-37347191

ABSTRACT

Eusocial bees (such as honey bees and bumble bees) harbor core gut microbiomes that are transmitted through social interaction between nestmates. Carpenter bees are not eusocial; however, recent microbiome analyses found that Xylocopa species harbor distinctive core gut microbiomes. In this study, we analyzed the gut microbiomes of three Xylocopa species in Japan between 2016 and 2021 by V1 to V2 region-based 16S rDNA amplicon sequencing, and 14 candidate novel species were detected based on the full-length 16S rRNA gene sequences. All Xylocopa species harbor core gut microbiomes consisting of primarily lactic acid bacteria (LAB) that were phylogenetically distant from known species. Although they were difficult to cultivate, two LAB species from two different Xylocopa species were isolated by supplementing bacterial culture supernatants. Both genomes exhibited an average LAB genome size with a large set of genes for carbohydrate utilization but lacked genes to synthesize an essential coenzyme NAD, which is unique among known insect symbionts. Our findings of phylogenetically distinct core LAB of NAD auxotrophy reflected the evolution of Xylocopa-restricted bacteria retention and maintenance through vertical transmission of microbes during solitary life. We propose five candidate novel species belonging to the families Lactobacillaceae and Bifidobacteriaceae, including a novel genus, and their potential functions in carbohydrate utilization. IMPORTANCE Recent investigations found unique microbiomes in carpenter bees, but the description of individual microbes, including isolation and genomics, remains largely unknown. Here, we found that the Japanese Xylocopa species also harbor core gut microbiomes. Although most of them were difficult to isolate a pure colony, we successfully isolated several strains. We performed whole-genome sequencing of the isolated candidate novel species and found that the two Lactobacillaceae strains belonging to the Xylocopa-specific novel LAB clade lack the genes for synthesizing NAD, a coenzyme central to metabolism in all living organisms. Here, we propose a novel genus for the two LAB species based on very low 16S rRNA gene sequence similarities and genotypic characters.


Subject(s)
Lactobacillales , Bees , Animals , Lactobacillales/genetics , NAD/genetics , Phylogeny , Symbiosis , RNA, Ribosomal, 16S/genetics , Carbohydrates
7.
DNA Res ; 30(3)2023 Jun 01.
Article in English | MEDLINE | ID: mdl-37253538

ABSTRACT

To quantify the biases introduced during human gut microbiome studies, analyzing an artificial mock community as the reference microbiome is indispensable. However, there are still limited resources for a mock community which well represents the human gut microbiome. Here, we constructed a novel mock community comprising the type strains of 18 major bacterial species in the human gut and assessed the influence of experimental and bioinformatics procedures on the 16S rRNA gene and shotgun metagenomic sequencing. We found that DNA extraction methods greatly affected the DNA yields and taxonomic composition of sequenced reads, and that some of the commonly used primers for 16S rRNA genes were prone to underestimate the abundance of some gut commensal taxa such as Erysipelotrichia, Verrucomicrobiota and Methanobacteriota. Binning of the assembled contigs of shotgun metagenomic sequences by MetaBAT2 produced phylogenetically consistent, less-contaminated bins with varied completeness. The ensemble approach of multiple binning tools by MetaWRAP can improve completeness but sometimes increases the contamination rate. Our benchmark study provides an important foundation for the interpretation of human gut microbiome data by providing means for standardization among gut microbiome data obtained with different methodologies and will facilitate further development of analytical methods.


Subject(s)
Gastrointestinal Microbiome , Microbiota , Humans , RNA, Ribosomal, 16S/genetics , Workflow , Microbiota/genetics , Metagenome , Metagenomics/methods
8.
Article in English | MEDLINE | ID: mdl-37185104

ABSTRACT

Obligately anaerobic, Gram-stain-positive, small-chain coccobacilli, strains 12EGH17T and 18CBH55, were isolated from faecal samples of healthy Japanese humans. Strain 12EGH17T showed the highest 16S rRNA gene sequence similarity to Sellimonas intestinalis BR72T (95.5 %), Coprococcus comes ATCC 27758T (94.4 %) and Clostridium nexile DSM 1787T (93.7 %). The percentage of conserved proteins values between the genome of strain 12EGH17T and that of the members of the genus Sellimonas were >54 %, suggesting that strain 12EGH17T belongs to the genus Sellimonas. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strains 12EGH17T and 18CBH55 were higher than the cut-off values of species demarcation (90 % dDDH and 99 % ANI), indicating these two strains are the same species. However, the dDDH and ANI values of these strains were lower than the cut-off values of species demarcation against other strains (<30 % dDDH and <79 % ANI). These results indicate that the isolates should be considered to represent a new species of the genus Sellimonas. The isolates were differentiated from the type species, S. intestinalis, by the ability of aesculin hydrolysis. Based on the collected data, strains 12EGH17T and 18CBH55 represent a novel species in the genus Sellimonas, for which the name Sellimonas catena sp. nov. is proposed. The type strain of S. catena is 12EGH17T (=JCM 35622T=DSM 114916T).


Subject(s)
Fatty Acids , Humans , RNA, Ribosomal, 16S/genetics , Fatty Acids/chemistry , Phylogeny , DNA, Bacterial/genetics , Bacterial Typing Techniques , Sequence Analysis, DNA , Base Composition , Feces , Nucleic Acid Hybridization
9.
Article in English | MEDLINE | ID: mdl-37103467

ABSTRACT

Two Gram-stain-negative, terminal endospore-forming, rod-shaped and aerotolerant bacterial strains designated D1-1T and B3 were isolated from soil samples of an organic paddy in Japan. Strain D1-1T grew at 15-37 °C, pH 5.0-7.3, and with up to 0.5 % (w/v) NaCl. Phylogenetic analysis of the 16S rRNA gene revealed that strain D1-1T belonged to the genus Clostridium and was closely related to Clostridium zeae CSC2T (99.7 % sequence similarity), Clostridium fungisolvens TW1T (99.7 %) and Clostridium manihotivorum CT4T (99.3 %). Strains D1-1T and B3 were whole-genome sequenced and indistinguishable, with an average nucleotide identity value of 99.7 %. The average nucleotide identity (below 91.1 %) and digital DNA-DNA hybridization (below 43.6 %) values between the two novel isolates and their corresponding relatives showed that strains D1-1T and B3 could be readily distinguished from their closely related species. A novel Clostridium species, Clostridium folliculivorans sp. nov., with type strain D1-1T (=MAFF 212477T=DSM 113523T), is proposed based on genotypic and phenotypic data.


Subject(s)
Fatty Acids , Phospholipids , Fatty Acids/chemistry , Phylogeny , RNA, Ribosomal, 16S/genetics , Japan , Base Composition , DNA, Bacterial/genetics , Bacterial Typing Techniques , Sequence Analysis, DNA , Clostridium/genetics , Nucleotides , Soil
10.
FEMS Microbiol Ecol ; 99(5)2023 04 07.
Article in English | MEDLINE | ID: mdl-36990641

ABSTRACT

Faecalibacterium prausnitzii is a promising biomarker of a healthy human microbiota. However, previous studies reported the heterogeneity of this species and found the presence of several distinct groups at the species level among F. prausnitzii strains. Our recent study revealed that methods previously developed for quantification of F. prausnitzii were not specific to the species level because of the heterogeneity within the F. prausnitzii species and the application of 16S rRNA gene, which is an invalid genetic marker for the species. Therefore, previously available data failed to provide information on different groups, which limits our understanding of the importance of this organism for host health. Here, we propose an alternative gene marker for quantification of F. prausnitzii-related taxa. A total of nine group-specific primer pairs were designed by targeting rpoA gene sequences. The newly developed rpoA-based qPCR successfully quantified targeted groups. Application of the developed qPCR assay in six healthy adults revealed marked differences in abundance and prevalence among the different targeted groups in stool samples. The developed assay will facilitate detailed understanding of the impact of Faecalibacterium populations at the group level on human health and to understand the links between depletion of specific groups in Faecalibacterium and different human disorders.


Subject(s)
Faecalibacterium prausnitzii , Microbiota , Adult , Humans , Faecalibacterium/genetics , Genetic Markers , RNA, Ribosomal, 16S/genetics , Faecalibacterium prausnitzii/genetics
11.
Methods Mol Biol ; 2588: 91-104, 2023.
Article in English | MEDLINE | ID: mdl-36418684

ABSTRACT

In their natural environments, microorganisms usually live in organized communities. Profiling analysis of microbial communities has recently assumed special relevance as it allows a thorough understanding of the diversity of the microbiota, its behavior over time, and the establishment of patterns associated with health and disease. The application of molecular biology approaches holds the advantage of including culture-difficult and as-yet-uncultivated phylotypes in the profiles, providing a more comprehensive picture of the microbial community. This chapter focuses on two particular techniques, namely terminal restriction fragment length polymorphism (T-RFLP) and denaturing gradient gel electrophoresis (DGGE), both of which have been widely used in environmental studies and have been recently successfully used by the authors in the study of the oral microbial communities associated with conditions of health and disease.


Subject(s)
Microbiota , Polymorphism, Restriction Fragment Length , Denaturing Gradient Gel Electrophoresis , Microbiota/genetics , Molecular Biology
12.
Int J Syst Evol Microbiol ; 72(10)2022 Oct.
Article in English | MEDLINE | ID: mdl-36269574

ABSTRACT

In this study, we isolated a novel strain of lactic acid bacteria, AF129T, from alfalfa silage prepared locally in Morioka, Iwate, Japan. Polyphasic taxonomy was used to characterize the bacterial strain. The bacterium was rod-shaped, Gram-stain-positive, non-spore-forming and catalase-negative. The strain grew at various temperatures (15-40°C) and pH levels (4.0-8.0). The optimum growth conditions were a temperature of 30°C and a pH of 6.0. AF129T exhibited growth at salt (NaCl) concentrations of up to 6.5 % (w/v). The G+C content of the strain's genomic DNA was 41.5 %. The major fatty acids were C16 : 0, C18 : 1ω9c, C19 : 0cyclo ω8c and summed feature 8. 16S rRNA gene sequencing revealed that AF129T represents a member of the genus Ligilactobacillus and it has higher sequence similarities with Ligilactobacillus pobuzihii (98.4 %), Ligilactobacillus acidipiscis (97.5 %) and Ligilactobacillus salitolerans (97.4 %). The digital DNA-DNA hybridization values for AF129T and phylogenetically related species of the genus Ligilactobacillus ranged from 19.8% to 24.1%. The average nucleotide identity of the strain with its closely related taxa was lower than the threshold (95 %-96 %) used for species differentiation. In the light of the above-mentioned physiological, genotypic, chemotaxonomic and phylogenetic evidence, we confirm that AF129T represents a member of the genus Ligilactobacillus and constitutes a novel species; we propose the name Ligilactobacillus pabuli sp. nov. for this species. The type strain is AF129T =MAFF 518002T =JCM 34518T=BCRC 81335T.


Subject(s)
Lactobacillales , Silage , Silage/microbiology , RNA, Ribosomal, 16S/genetics , Phylogeny , Base Composition , Medicago sativa , Catalase/genetics , Bacterial Typing Techniques , DNA, Bacterial/genetics , Lactobacillales/genetics , Sodium Chloride , Sequence Analysis, DNA , Fatty Acids/chemistry , Nucleotides
13.
Anaerobe ; 77: 102642, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36113733

ABSTRACT

This study revealed an interaction between the gut commensal bacterium Bacteroides thetaiotaomicron JCM 5827T and asaccharolytic bacterium Dialister hominis JCM 33369T, which uses succinate instead of carbohydrates for growth. D. hominis usually forms extremely small colonies on Brucella blood agar plates. However, when co-cultured with B. thetaiotaomicron, D. hominis grew noticeably and formed larger colonies than those in the single culture, especially near B. thetaiotaomicron colonies. Although D. hominis barely grew in Gifu anaerobic medium broth, adding 1% succinate improved its growth. In the mixed culture, the succinate produced by B. thetaiotaomicron was mostly converted to propionate. This result was consistent with the single culture of D. hominis in the succinate-containing broth and our previous report on Phascolarctobacterium faecium, a succinate-utilizing gut bacterium. Our series of studies suggests that syntrophy within the human gut microbiota occurs via succinate.


Subject(s)
Bacteroides thetaiotaomicron , Gastrointestinal Microbiome , Humans , Succinic Acid , Succinates
14.
Article in English | MEDLINE | ID: mdl-35416766

ABSTRACT

Faecalibacterium prausnitzii is one of the most important butyrate-producing bacteria in the human gut. Previous studies have suggested the presence of several phylogenetic groups, with differences at the species level, in the species, and a taxonomic re-evaluation is thus essential for further understanding of ecology of the important human symbiont. Here we examine the phenotypic, physiological, chemotaxonomic and phylogenomic characteristics of six F. prausnitzii strains (BCRC 81047T=ATCC 27768T, A2-165T=JCM 31915T, APC918/95b=JCM 39207, APC942/30-2=JCM 39208, APC924/119=JCM 39209 and APC922/41-1T=JCM 39210T) deposited in public culture collections with two reference strains of Faecalibacterium butyricigenerans JCM 39212T and Faecalibacterium longum JCM 39211T. Faecalibacterium sp. JCM 17207T isolated from caecum of broiler chicken was also included. Three strains of F. prausnitzii (BCRC 81047T, JCM 39207 and JCM 39209) shared more than 96.6 % average nucleotide identity (ANI) and 69.6 % digital DNA-DNA hybridization (dDDH) values, indicating that the three strains are members of the same species. On the other hand, the remaining three strains of F. prausnitzii (JCM 31915T, JCM 39208 and JCM 39210T) were clearly separated from the above three strains based on the ANI and dDDH values. Rather, JCM 39208 showed ANI and dDDH values over the cut-off values of species discrimination (>70 % dDDH and >95-96 % ANI) with F. longum JCM 39211T, whereas JCM 31915T, JCM 39210T and JCM 17207T did not share dDDH and ANI values over the currently accepted cut-off values with any of the tested strains, including among them. Furthermore, the cellular fatty acid patterns of these strains were slightly different from other F. prausnitzii strains. Based on the collected data, F. prausnitzii JCM 31915T, F. prausnitzii JCM 39210T and Faecalibacterium sp. JCM 17207T represent three novel species of the genus Faecalibacterium, for which the names Faecalibacterium duncaniae sp. nov. (type strain JCM 31915T=DSM 17677T=A2-165T), Faecalibacterium hattorii sp. nov. (type strain JCM 39210T=DSM 107841T=APC922/41-1T) and Faecalibacterium gallinarum sp. nov. (type strain JCM 17207T=DSM 23680T=ic1379T) are proposed.


Subject(s)
Chickens , Fatty Acids , Animals , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Faecalibacterium , Fatty Acids/chemistry , Nucleic Acid Hybridization , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
15.
Article in English | MEDLINE | ID: mdl-35254232

ABSTRACT

The genus Prevotella plays an important role in polysaccharide degradation and fermentation in the rumen. To further understand the function of the phylogenetically diverse genus Prevotella, it is necessary to explore the individual characteristics at the species level. In this study, Gram-negative anaerobic bacterial strains isolated from the rumen of Holstein cows were identified. Strain R5019T was classified within the genus Prevotella based on 16S rRNA gene sequence-based phylogenetic analysis. The values of 16S rRNA gene sequence similarity, average nucleotide identity and digital DNA-DNA hybridization between strain R5019T and its phylogenetically nearest species Prevotella multisaccharivorax PPPA20T were 89.8, 82.6, and 29.3 %, respectively. The genome size of R5019T was estimated to be ca. 4.19 Mb with a genomic G+C content of 49.5 mol%. The major cellular fatty acids and menaquinones were C15 : 0 anteiso and C17 : 0 anteiso and MK-11 and MK-12, respectively. Succinate, lactate, malate, acetate and formate were produced as the fermentation end products using glucose. Based on phylogenetic, physiological, biochemical and genomic differences between 11 strains and other phylogenetically related Prevotella species, a novel species, Prevotella lacticifex sp. nov., is proposed within the genus Prevotella. The type strain is R5019T (=JCM 34664T=DSM 112675T).


Subject(s)
Fatty Acids , Rumen , Animals , Bacterial Typing Techniques , Base Composition , Cattle , DNA, Bacterial/genetics , Fatty Acids/chemistry , Female , Phylogeny , Prevotella , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
16.
J Infect Chemother ; 28(5): 678-683, 2022 May.
Article in English | MEDLINE | ID: mdl-35177351

ABSTRACT

INTRODUCTION: This study aimed to describe the changes in the intensive care burden of coronavirus disease 2019 (COVID-19) during the first year of outbreak in Japan. METHODS: This retrospective cohort study included COVID-19 patients who received mechanical ventilation (MV) support in two designated hospitals for critical patients in Kawasaki City. We compared the lengths of MV and stay in the intensive care unit (ICU) or high care unit (HCU) according to the three epidemic waves. We calculated in-hospital mortality rates in patients with or without MV. RESULTS: The median age of the sample was 65.0 years, and 22.7% were women. There were 37, 29, and 62 patients in the first (W1), second (W2), and third waves (W3), respectively. Systemic steroids, remdesivir, and prone positioning were more frequent in W2 and W3. The median length of MV decreased from 18.0 days in W1 to 13.0 days in W3 (P = 0.019), and that of ICU/HCU stay decreased from 22.0 days in W1 to 15.5 days in W3 (P = 0.027). The peak daily number of patients receiving MV support was higher at 18 patients in W1, compared to 8 and 15 patients in W2 and W3, respectively. The mortality rate was 23.4%, which did not significantly change (P = 0.467). CONCLUSIONS: The lengths of MV and ICU/HCU stay per patient decreased over time. Despite an increase in the number of COVID-19 patients who received MV in W3, this study may indicate that the intensive care burden during the study period did not substantially increase.


Subject(s)
COVID-19 , Aged , COVID-19/epidemiology , Critical Care , Disease Outbreaks , Female , Humans , Intensive Care Units , Japan/epidemiology , Respiration, Artificial , Retrospective Studies , SARS-CoV-2 , Tertiary Care Centers
17.
Int J Syst Evol Microbiol ; 71(12)2021 Dec.
Article in English | MEDLINE | ID: mdl-34870581

ABSTRACT

Two obligately anaerobic, Gram-stain-positive, rod-shaped bacteria were isolated from faecal samples of healthy humans in Japan. 16S rRNA gene sequence analysis indicated that these two strains (8CFCBH1T and 9CBH6) belonged to the genus Adlercreutzia, which is known as an equol-producing bacterium. The closest neighbours of strain 8CFCBH1T were Adlercreutzia equolifaciens subsp. equolifaciens DSM 19450T (98.6%), Adlercreutzia equolifaciens subsp. celatus do03T (98.4%), Adlercreutzia muris WCA-131-CoC-2T (96.6%), Parvibacter caecicola NR06T (96.4%), Adlercreutzia caecimuris B7T (95.3%) and Adlercreutzia mucosicola Mt1B8T (95.3%). The closest relatives to strain 9CBH6 were A. equolifaciens subsp. equolifaciens DSM 19450T (99.8%), A. equolifaciens subsp. celatus do03T (99.6%) and A. muris WCA-131-CoC-2T (96.8%). Strain 8CFCBH1T showed 22.3-53.5% digital DNA-DNA hybridization (dDDH) values with its related species. In addition, the average nucleotide identity (ANI) values between strain 8CFCBH1T and its related species ranged from 75.4 to 93.3%. On the other hand, strain 9CBH6 was considered as A. equolifaciens based on the dDDH and ANI values (>70% dDDH and >95-96% ANI). Strain 9CBH6 showed daidzein-converting activity, as expected from the result of genome analysis. The genome of strain 8CFCBH1T lacked four genes involved in equol production. Growing cells of strain 8CFCBH1T were not capable of converting daidzein. Based on the collected data, strain 8CFCBH1T represents a novel species in the genus Adlercreutzia, for which the name Adlercreutzia hattorii sp. nov. is proposed. The type strain of A. hattorii is 8CFCBH1T (=JCM 34083T=DSM 112284T).


Subject(s)
Actinobacteria/classification , Equol , Phylogeny , Actinobacteria/isolation & purification , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Equol/biosynthesis , Feces/microbiology , Humans , Japan , Nucleic Acid Hybridization , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
18.
Int J Syst Evol Microbiol ; 71(12)2021 Dec.
Article in English | MEDLINE | ID: mdl-34913426

ABSTRACT

In Japan, during a screening of lactic acid bacteria in spent mushroom substrates, an unknown bacterium was isolated and could not be assigned to any known species. Strain YK48GT is Gram-stain-positive, rod-shaped, non-motile, non-spore-forming and catalase-negative. The isolate grew in 0-4 % (w/v) NaCl, at 15-37 °C (optimum, 30 °C) and at pH 4.0-8.0 (optimum, pH 6.0). The genomic DNA G+C content of strain YK48GT was 42.5 mol%. Based on its 16S rRNA gene sequence, strain YK48GT represented a member of the genus Lentilactobacillus and showed the highest pairwise similarity to Lentilactobacillus rapi DSM 19907T (97.86 %). Phylogenetic analyses based on amino acid sequences of 466 shared protein-encoding genes also revealed that the strain was phylogenetically positioned in the genus Lentilactobacillus but did not suggest an affiliation with previously described species. The average nucleotide identity and digital DNA-DNA hybridization values between strain YK48GT and the type strains of phylogenetically related species were 72.2-76.6% and 19.0-21.2 %, respectively, indicating that strain YK48GT represents a novel species within the genus Lentilactobacillus. Phenotypic data further confirmed the differentiation of strain YK48GT from other members of the genus Lentilactobacillus. According to the results of the polyphasic characterization presented in this study, strain YK48GT represents a novel species of the genus Lentilactobacillus, for which the name Lentilactobacillus fungorum sp. nov. is proposed. The type strain is YK48GT (=JCM 32598T=DSM 107968T).


Subject(s)
Agaricales , Lactobacillaceae/classification , Phylogeny , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/chemistry , Japan , Lactobacillaceae/isolation & purification , Nucleic Acid Hybridization , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
19.
Microbiol Resour Announc ; 10(48): e0078521, 2021 Dec 02.
Article in English | MEDLINE | ID: mdl-34854722

ABSTRACT

Here, we report the complete genome sequence of Megamonas funiformis strain 1CBH44, which was isolated from the feces of a healthy Japanese person. The genome consists of a circular chromosome (2,310,709 bp, with a GC content of 31.5%) and possesses 2,170 putative protein-coding genes, 18 rRNA genes, and 54 tRNA genes.

20.
Int J Syst Evol Microbiol ; 71(11)2021 Nov.
Article in English | MEDLINE | ID: mdl-34748474

ABSTRACT

A rod-shaped, Gram-stain-negative, strictly anaerobic, catalase-negative and endospore-forming bacterial strain CSC2T was isolated from corn silage preserved in Tochigi, Japan. The strain CSC2T grew at 15-40 °C, at pH 5.0-7.7 and with up to 0.5 % (w/v) NaCl. The main cellular fatty acids were C14 : 0, C16 : 0 and C16 : 0 dimethyl acetal. The cellular polar lipids detected were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidic acid, lysophosphatidylethanolamine, phosphatidylserine, lysophosphatidylcholine and two unidentified polar lipids. Phylogenetic analysis of the 16S rRNA gene showed that strain CSC2T was a member of the genus Clostridium and closely related to Clostridium polyendosporum DSM 57272T (95.6 % gene sequence similarity) and Clostridium fallax ATCC 19400T (95.3 %). The genomic DNA G+C content of strain CSC2T was 31.1 mol% (whole genome analysis). The average nucleotide identity based on blast and digital DNA-DNA hybridization values between strain CSC2T and the type strains of phylogenetically related species were below 71 and 24 %, respectively. On the basis of the genotypic, phenotypic and chemotaxonomic characteristics, it is proposed to designate strain CSC2T as representing Clostridium zeae sp. nov. The type strain is CSC2T (=MAFF212476T=JCM 33766T=DSM 111242T).


Subject(s)
Clostridium/classification , Phylogeny , Silage , Zea mays , Bacterial Typing Techniques , Base Composition , Clostridium/isolation & purification , DNA, Bacterial/genetics , Fatty Acids/chemistry , Japan , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Silage/microbiology , Zea mays/microbiology
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