Vogesella fluminis sp. nov., isolated from a freshwater river, and emended description of the genus Vogesella

Hydrological characteristics strongly dominate the spatiotemporal variation of bacterioplankton sub-communities in the Yangtze River Estuary

Seasonal variations in river discharge in estuarine ecosystems drive dynamic interactions between freshwater and seawater, significantly impacting the structure and functionality of bacterioplankton sub-communities. Seasonal saltwater intrusion during the dry season intensifies the dynamic variations in water quality and salinity between the northern and southern branches of the Yangtze River Estuary, further complicating the ecological processes governing bacterioplankton communities. Nevertheless, the mechanisms underlying these processes and their effects on distinct bacterioplankton sub-communities remain insufficiently explored. In this study, the composition, functions, and assembly mechanisms of bacterioplankton communities in the Yangtze River Estuary during different hydrological periods were examined using molecular technique and various statistical analysis methods. The results showed that rare sub-communities exhibited the highest α-diversity, abundant and transient sub-communities primarily contributed to the diversity differences across hydrological periods. Saltwater intrusion into the northern branch altered bacterioplankton community and weakened the distance-decay pattern of the transient and rare sub-communities. Additionally, stochastic processes governed the assembly of rare sub-communities, and saltwater intrusion disrupted their migration and dispersal patterns. In contrast, abundant and transient sub-communities maintain their stability by adjusting their ecological strategies in response to salinity changes. Functional analysis indicated that external nutrient inputs and hydrodynamic changes in the wet season promoted community functional diversity and activity, while abundant sub-communities in the dry season were more effective at occupying resources and performing specific functions related to carbon cycling. These findings highlight the relationships between bacterioplankton sub-communities and environmental changes in estuarine ecosystems, underscoring their key roles in biogeochemical cycling.

Vogesella oryzagri sp. nov., isolated from the rhizosphere of rice and in silico genome mining for the prediction of biosynthetic gene clusters

A Gram-stain-negative, aerobic, rod-shaped, motile and flagellated novel bacterial strain, designated MAHUQ-64T, was isolated from the rhizosphere of rice. The colonies were observed to be creamy white-coloured, smooth, spherical and 0.5-1.1 mm in diameter when grown on Reasoner's 2A agar medium for 2 days. Strain MAHUQ-64T was able to grow at 10-40 °C, at pH 5.0-9.5 and in the presence of 0-2.0% NaCl (w/v). The strain was positive for both catalase and oxidase tests. The strain was positive for hydrolysis of l-tyrosine. According to the 16S rRNA gene sequence comparisons, the isolate was identified as a member of the genus Vogesella and is closely related to Vogesella oryzae L3B39T (98.6% sequence similarity) and Vogesella facilis TTM-24T (98.2%). The novel strain MAHUQ-64T has a draft genome size of 3 827 146 bp (22 contigs), annotated with 3612 protein-coding genes, 74 tRNA and 4 rRNA genes. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain MAHUQ-64T and its closest member V. oryzae L3B39T were 86.5 and 33.4%, respectively. In silico genome mining revealed several biosynthetic gene clusters in the genome of the novel strain MAHUQ-64T. The genomic DNA G+C content was determined to be 63.4 mol%. The predominant isoprenoid quinone was ubiquinone-8. The major fatty acids were identified as summed feature 3 (comprising C16  :  1 ω7c and/or C16  :  1 ω6c) and C16  :  0. Based on dDDH, ANI value, genotypic analysis and chemotaxonomic and physiological data, strain MAHUQ-64T represents a novel species within the genus Vogesella, for which the name Vogesella oryzagri sp. nov. is proposed, with MAHUQ-64T (=KACC 22245T=CGMCC 1.19000T) as the type strain.

Vogesella aquatica sp. nov. and Vogesella margarita sp. nov., isolated from rivers in Southwest China

Eight Gram-stain-negative, aerobic, short rod-shaped and motile strains (DC21WT, LYT5WT, LYT10W, LYT16W, LYT22W, LYT23W, LYT24W and SH7W) were isolated from rivers in Southwest China. Comparisons based on the 16S rRNA gene sequences showed that strain DC21WT shared the highest 16S rRNA gene sequence similarity (99.6 %) with Vogesella mureinivorans 389T, strain LYT5WT shared 99.2 % with Vogesella fluminis Npb-07T, and the other isolated strains took Vogesella indigofera DSM 3303T as their most similar strain, respectively. The phylogenetic trees reconstructed based on the 16S rRNA gene sequences also supported that strains V. mureinivorans 389T, V. fluminis Npb-07T and V. indigofera DSM 3303T were the closest neighbours of the isolated strains. The phylogenomic tree showed similar phylogenetic relationships among these strains. The calculated OrthoANIu and digital DNA-DNA hybridization values among strains DC21WT, LYT5WT and other related strains were less than 93.7 and 53.7 %, respectively. The calculated OrthoANIu and digital DNA-DNA hybridization values among strains LYT10W, LYT16W, LYT22W, LYT23W, LYT24W, SH7W and V. indigofera DSM 3303T ranged from 94.8 to 97.2 % and from 59.8 to 74.9 %, respectively. Although these values were located in the transition region of species demarcation, their similar phenotypic, biochemical and genotypic characteristics supported that these six strains should be assigned to the species V. indigofera. Comparative genomic analyses showed that only V. indigofera DSM 3303T harboured 19 genes encoding the Type VI secretion system. Combining above descriptions, strains DC21WT and LYT5WT should represent two independent novel species of the genus Vogesella, for which the names Vogesella aquatica sp. nov. (type strain DC21WT=GDMCC 1.3220T=KCTC 92556T) and Vogesella margarita sp. nov. (type strains LYT5WT=GDMCC 1.3213T=KCTC 92549T) are proposed, respectively.

Neotropical Frog Foam Nest’s Microbiomes

Amphibian foam nests are unique microenvironments that play a crucial role in the development of tadpoles. They contain high levels of proteins and carbohydrates, yet little is known about the impact of their microbiomes on tadpole health. This study provides a first characterization of the microbiome of foam nests from three species of Leptodactylids (Adenomera hylaedactyla, Leptodactylus vastus, and Physalaemus cuvieri) by investigating the DNA extracted from foam nests, adult tissues, soil, and water samples, analyzed via 16S rRNA gene amplicon sequencing to gain insight into the factors driving its composition. The results showed that the dominant phyla were proteobacteria, bacteroidetes, and firmicutes, with the most abundant genera being Pseudomonas, Sphingobacterium, and Paenibacillus. The foam nest microbiomes of A. hylaedactyla and P. cuvieri were more similar to each other than to that of L. vastus, despite their phylogenetic distance. The foam nests demonstrated a distinct microbiome that clustered together and separated from the microbiomes of the environment and adult tissue samples. This suggests that the peculiar foam nest composition shapes its microbiome, rather than vertical or horizontal transference forces. We expanded this knowledge into amphibian foam nest microbiomes, highlighting the importance of preserving healthy foam nests for amphibian conservation.

Complete Genome Sequences of Kinneretia sp. Strain XES5, Shinella sp. Strain XGS7, and Vogesella sp. Strain XCS3, Isolated from Xenopus laevis Skin

Here, we report the genome sequences of three bacterial isolates, Kinneretia sp. strain XES5, Shinella sp. strain XGS7, and Vogesella sp. strain XCS3, which were cultured from skin of adult female laboratory-bred Xenopus laevis.

Vogesella perlucida-induced bacteremia in an advanced-age patient: first case report

Background

Vogesella species are common aquatic, Gram-negative rod-shaped bacteria, originally described in 1997. Vogesella perlucida was first isolated from spring water in 2008. Furthermore, bacterial pathogenicity of Vogesella perlucida has never been reported. Here, we report the first case of rare Vogesella perlucida-induced bacteremia in an advanced-age patient with many basic diseases and history of dexamethasone abuse.

Case presentation

A 71-year-old female was admitted with inflamed upper and lower limbs, rubefaction, pain and fever (about 40 °C). She had been injured in a fall at a vegetable market and then touched river snails with her injury hands. A few days later, soft tissue infection of the patient developed and worsened. Non-pigmented colonies were isolated from blood cultures of the patient. Initially, Vogesella perlucida was wrongly identified as Sphingomonas paucimobilis by Vitek-2 system with GN card. Besides, we failed to obtain an acceptable identification by the MALDI-TOF analysis. Finally, the isolated strain was identified as Vogesella perlucida by 16S rRNA gene sequences. In addition, the patient recovered well after a continuous treatment of levofloxacin for 12 days.

Conclusion

Traditional microbiological testing system may be inadequate in the diagnosis of rare pathogenic bacteria. Applications of molecular diagnostics techniques have great advantages in clinical microbiology laboratory. By using 16S rRNA gene sequence analysis, we report the the first case of rare Vogesella perlucida-induced bacteremia.

Temperature governs the distribution of hot spring microbial community in three hydrothermal fields, Eastern Tibetan Plateau Geothermal Belt, Western China

The eastern Tibetan Plateau geothermal belt in the southwest of China hosts a number of hot springs with a wide range of temperature and hydrogeochemical conditions, which may harbor different niches for the distribution of microbial communities. In this study, we investigated hydrochemical characteristics and microbial community composition in 16 hot springs with a temperature range of 34.6 to 88.2 °C within and across three typical hydrothermal fields (Kangding, Litang, and Batang). According to aquifer lithologic and tectonic differences, the hydrochemical compositions of hot springs displayed an apparent regional-specific pattern with distinct distributions of major and trace elements (e.g., Ca²⁺, Mg²⁺, F^-/B) and were primarily formed by water-rock interaction across the three hydrothermal fields. Nonetheless, microbial communities significantly assembled with the temperature rather than the geographic locations with distinct hydrogeological features. Low temperature (<45 °C), moderate temperature (55-70 °C) and high temperature (>70 °C) groups were identified based on their community compositions. Proteobacteria and Nitrospirae were the predominant phyla in low-temperature hot springs, while in moderate to high-temperature springs they were mainly composed of Aquificae, Deinococcus-Thermus, Thermodesulfobacteria, Thermotogae and Cyanobacteria. Variation partition analysis suggested a higher explanation of temperature (29.6%) than spatial variable (1.8%) and other geochemical variables (2.5%) on the microbial distribution. Microbial co-occurrence network showed >80% negative associations hinting a low co-existence pattern and highlighted the driving force of temperature as well as F^- or total organic carbon (TOC) for microbial interactions. Microbial dissimilarity displayed significant linear correlations with environmental (temperature) and geographic distance in Batang but only with temperature in Kangding area, which might be attributed to the regional-specific hydrogeochemistry. This study may help us to better understand the distribution of the microbial community in hot spring across different hydrothermal fields.

Pesticides Decrease Bacterial Diversity and Abundance of Irrigated Rice Fields

Bacteria play an important role in soil ecosystems and their activities are crucial in nutrient composition and recycling. Pesticides are extensively used in agriculture to control pests and improve yield. However, increased use of pesticides on agricultural lands results in soil contamination, which could have adverse effect on its bacterial communities. Here, we investigated the effect of pesticides commonly used on irrigated rice fields on bacterial abundance and diversity. Irrigated soil samples collected from unexposed, pesticide-exposed, and residual exposure areas were cultured under aerobic and anaerobic conditions. DNA was extracted and analysed by 16S rRNA sequencing. The results showed overall decrease in bacterial abundance and diversity in areas exposed to pesticides. Operational taxonomic units of the genera Enterobacter, Aeromonas, Comamonas, Stenotrophomonas, Bordetella, and Staphylococcus decreased in areas exposed to pesticides. Conversely, Domibacillus, Acinetobacter, Pseudomonas, and Bacillus increased in abundance in pesticide-exposed areas. Simpson and Shannon diversity indices and canonical correspondence analysis demonstrated a decrease in bacterial diversity and composition in areas exposed to pesticides. These results suggest bacteria genera unaffected by pesticides that could be further evaluated to identify species for bioremediation. Moreover, there is a need for alternative ways of improving agricultural productivity and to educate farmers to adopt innovative integrated pest management strategies to reduce deleterious impacts of pesticides on soil ecosystems.

Vogesella urethralis sp. nov., isolated from human urine, and emended descriptions of Vogesella perlucida and Vogesella mureinivorans

A novel Vogesella strain, YM-1^T, was recovered from human urine in PR China in 2017. Cells of strain YM-1^T were Gram-stain-negative, rod-shaped, aerobic, motile, non-spore-forming and poly-β-hydroxybutyrate-accumulating. The strain contained C_16:1ω6c/C _16:1ω7c, C_16:0 and C_18:0ω7c as major fatty acids; phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an unidentified phospholipid as major polar lipids; and ubiquinone-8 as the predominant respiratory quinone. Comparison of 16S rRNA gene sequences indicated that this strain had highest similarities to Vogesella perlucida DS-28^T (98.8 %) and Vogesella mureinivorans 389^T (98.1 %). The results of phylogenetic analysis based on the 16S rRNA gene sequences revealed that the novel strain was clustered and well separated with V. perlucida DS-28^T and V. mureinivorans 389^T within the genus Vogesella. The average nucleotide identity (ANI) and amino acid identity (AAI) analyses showed that this strain was not identified as V. perlucida DS-28^T or V. mureinivorans 389^T, with values well below the threshold limit for species demarcation (ANI <88.1 %, AAI <88.6 %). Based on the above results, strain YM-1^T is proposed to be a novel species of the genus Vogesella with the name Vogesella urethralis sp. nov. (YM-1^T=NBRC 113779=CGMCC 1.17135).

Vogesella amnigena sp. nov., isolated from a freshwater river

A bacterial strain, designated Npb-02T, was isolated from a freshwater river in Taiwan and characterized in a taxonomic study using a polyphasic approach. Cells of strain Npb-02T were Gram-stain-negative, aerobic, poly-β-hydroxybutyrate-accumulating, rod-shaped and non-motile. Growth occurred at 15–40 °C (optimum 25–30 °C), at pH 7.0–8.0 (optimum pH 7.0) and with 0–1 % NaCl (optimum 0.5 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain Npb-02T belonged to the genus Vogesella and was most closely related to Vogesella perlucida DS-28T with sequence similarity of 98.3 %. Strain Npb-02T contained summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0 as the major fatty acids. The major respiratory quinone was Q-8.The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an uncharacterized aminophospholipid and an uncharacterized phospholipid. The genomic DNA G+C content of strain Npb-02T was 64.1 mol%. The DNA–DNA hybridization values for strain Npb-02T with Vogesella perlucida DS-28T, Vogesella mureinivorans 389T and Vogesella lacus GR13T were less than 25 %. On the basis of phylogenetic inference and phenotypic data, strain Npb-02T represents a novel species of the genus Vogesella, for which the name Vogesella amnigena sp. nov. is proposed. The type strain is Npb-02T ( = BCRC 80887T = LMG 28419T = KCTC 42195T).

Vogesella facilis sp. nov., isolated from a freshwater river, and emended description of the genus Vogesella

A bacterial strain, designated TTM-24T, was isolated from a freshwater river in Taiwan and characterized using a polyphasic taxonomic approach. Cells of strain TTM-24T were Gram-stain-negative, facultatively anaerobic, poly-β-hydroxybutyrate-accumulating, motile by a single polar flagellum, rod-shaped, with rods surrounded by a thick capsule and forming white-coloured colonies. Growth occurred at 15-37 °C (optimum, 25 °C), at pH 6.0-8.0 (optimum, pH 7.0) and with 0-1 % NaCl (optimum, 0.5 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain TTM-24T belonged to the genus Vogesella and was most closely related to 'Vogesella amnigena' Npb-02 with sequence similarity of 97.1 %. Strain TTM-24T contained summed feature 3 (comprising C16 : 1 ω7c and/or C16 : 1 ω6c) and C16 : 0 as the major fatty acids. The major respiratory quinone was Q-8. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an uncharacterized aminophospholipid and two uncharacterized phospholipids. The genomic DNA G+C content of strain TTM-24T was 67.4 mol%. The DNA-DNA hybridization value for strain TTM-24T with 'V. amnigena' Npb-02 was less than 45 %. On the basis of the phylogenetic inference and phenotypic data, strain TTM-24T should be classified as a novel species, for which the name Vogesella facilis sp. nov. is proposed. The type strain is TTM-24T ( = BCRC 80912T = KCTC 42742T = LMG 29003T).

Description of Vogesella oryzae sp. nov., isolated from the rhizosphere of saline tolerant pokkali rice

Three strains, namely L3B39(T), L3D16, and L1E9, were obtained while studying the cultivable rhizosphere bacteria of saline tolerant pokkali rice, at Kerala, India. The novel strains were negative for many plant growth promoting plate assays such as phytohormone and siderophore production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase and growth in nitrogen free agar medium but found to utilize malic acid, citrate, D-glucose, L-arabinose, and D-maltose, important components of the plant root exudates, indicating that they are normal plant rhizosphere residents without yet known benefits to the plant. The 16S rRNA gene analysis placed these strains in the genus Vogesella, forming a separate branch independent of the previously described type strains of this genus in all tree making algorithms applied. Vogesella perlucida DS-28(T) was the type strain with highest 16S rRNA sequence similarity (97.59%). DNA-DNA hybridization values among these novel strains were above 85% andthat with Vogesella perlucida LMG 24214(T) was below 50%. Phenotypically, the novel strains can be differentiated from Vogesella perlucida LMG 24214(T) by many characters such as NaCl tolerance, growth temperature, and utilization of L-arabinose, D-maltose, and citrate. These novel strains contain C16:1ω6c/C16:1ω7c and C16:0 as major fatty acids, ubiquinone Q-8 as the major respiratory quinone, and phosphatidylethanolamine and phosphatidylglycerol as major polar lipids. Based on the results obtained from the polyphasic taxonomic approach we conclude that the strains belong to a novel Vogesella species for which the name Vogesella oryzae sp.nov. is proposed. The type strain is L3B39(T) (= LMG 28272(T)=DSM 28780(T)).

Rivicola pingtungensis gen. nov., sp. nov., a new member of the family Neisseriaceae isolated from a freshwater river

A bacterial strain, designated Npb-03(T), was isolated from a freshwater river in Taiwan and was characterized using a polyphasic taxonomic approach. The cells were Gram-reaction-negative, straight rod-shaped, non-motile, non-spore-forming and facultatively anaerobic. Growth occurred at 10-37 °C (optimum, 30-35 °C), at pH 6.0-8.0 (optimum, pH 6.0-7.0) and with 0-1.0% NaCl (optimum, 0%). The predominant fatty acids were summed feature 3 (comprising C(16 : 1)ω7c and/or C(16 : 1)ω6c) and C(16 : 0). The major isoprenoid quinone was Q-8 and the DNA G+C content was 64.1 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an uncharacterized aminolipid and three uncharacterized phospholipids. The major polyamines were putrescine, 2-hydroxyputrescine, cadaverine and spermidine. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain Npb-03(T) forms a distinct lineage with respect to closely related genera within the family Neisseriaceae of the class Betaproteobacteria, most closely related to the genera Aquaspirillum, Laribacter, Leeia and Microvirgula, and the levels of 16S rRNA gene sequence similarity with respect to the type species of related genera are less than 93%. On the basis of the genotypic and phenotypic data, strain Npb-03(T) represents a novel genus and species of the family Neisseriaceae, for which the name Rivicola pingtungensis gen. nov., sp. nov. is proposed. The type strain is Npb-03(T) ( = BCRC 80376(T) = LMG 26668(T) = KCTC 23712(T)).