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Microbial communities play a crucial role in the physiology of animal hosts; however, little is known about bacterial symbionts with the group cephalopods, specifically octopuses, and the function of these symbionts. The goal of this study was to determine if octopuses have a unique skin microbiome. The skin microbiome of two sympatric octopuses (Octopus vulgaris and Macrotritopus defilippi) was compared with the surrounding environment, sediment and seawater, to determine if octopus have a unique skin microbiome. High throughput sequencing of the bacterial 16S rRNA gene (V3-V4 region) amplicons was performed using an Illumina MiSeq. Sediment showed the greatest alpha diversity followed by octopus then seawater. Beta diversity revealed a difference in microbial composition between the octopus skin microbiome and sediment and seawater. While phylum Bacteroidetes appeared rare in environmental samples, it was most abundant for the octopus skin microbiome with the majority of the bacteria comprising the family Flavobacteriaceae. Proteobacteria, the largest group of bacteria, also constituted the octopus skin microbiome. Many of these groups occur on both octopus species; however, certain taxa differed in relative abundance between octopus species and may show species-specific host selection. Several bacteria that were identified for the octopus skin microbiome have been isolated from other marine animal hosts, identified as biodegraders and/ or produce pigments and squalene, or act as predators of other bacteria. These groups may play a role in defense against environmental stressors or pathogenic bacteria. This is the first study to characterize the skin microbiome in two wild sympatric octopuses. Due to the importance of bacterial symbionts, this can provide insight to the physiology, behavior, ecology, and ultimately the health of these important animals in marine environments as well as care in captive or laboratory settings. [ABSTRACT FROM AUTHOR]

We performed chlorine inactivation experiments for Elizabethkingia anophelis and E. meningoseptica bacterial strains from clinical and environmental sources. Free chlorine concentration × contact time values

The axolotl (Ambystoma mexicanum) is renowned for its remarkable regenerative capabilities, which are not diminished by the transition from a neotenic to a metamorphic state. This study explored the microbiome dynamics in axolotl limb regeneration by examining the microbial communities present in neotenic and metamorphic axolotls at two critical stages of limb regeneration: pre-amputation and during blastema formation. Utilizing 16S rRNA amplicon sequencing, we investigated the variations in microbiome profiles associated with different developmental and regenerative states. Our findings reveal a distinct separation in the microbiome profiles of neotenic and metamorphic samples, with a clear demarcation in microbial composition at both the phylum and genus levels. In neotenic 0DPA samples, Proteobacteria and Firmicutes were the most abundant, whereas in neotenic 7DPA samples, Proteobacteria and Bacteroidetes dominated. Conversely, metamorphic samples displayed a higher abundance of Firmicutes and Bacteroidetes at 0DPA and Proteobacteria and Firmicutes at 7DPA. Alpha and beta diversity analyses, along with dendrogram construction, demonstrated significant variations within and between the sample groups, suggesting a strong influence of both developmental stage and regenerative state on the microbiome. Notably, Flavobacterium and Undibacterium emerged as distinctive microbial entities in neotenic 7DPA samples, highlighting potential key players in the microbial ecology of regeneration. These findings suggest that the axolotl's microbiome is dynamically responsive to blastema formation, and they underscore the potential influence of microbial communities on the regeneration process. This study lays the groundwork for future research into the mechanisms by which the microbiome may modulate regenerative capacity. [ABSTRACT FROM AUTHOR]

Flavobacterial diseases, caused by bacteria in the order Flavobacteriales, are responsible for devastating losses in farmed and wild fish populations worldwide. The genera Flavobacterium (Family Flavobacteriaceae) and Chryseobacterium (Weeksellaceae) encompass the most well-known agents of fish disease in the order, but the full extent of piscine-pathogenic species within these diverse groups is unresolved, and likely underappreciated. To identify emerging agents of flavobacterial disease in US aquaculture, 183 presumptive Flavobacterium and Chryseobacterium isolates were collected from clinically affected fish representing 19 host types, from across six western states. Isolates were characterized by 16S rRNA gene sequencing and phylogenetic analysis using the gyrB gene. Antimicrobial susceptibility profiles were compared between representatives from each major phylogenetic clade. Of the isolates, 52 were identified as Chryseobacterium species and 131 as Flavobacterium. The majority of Chryseobacterium isolates fell into six clades (A-F) consisting of ≥ 5 fish isolates with ≥ 70% bootstrap support, and Flavobacterium into nine (A-I). Phylogenetic clades showed distinct patterns in antimicrobial susceptibility. Two Chryseobacterium clades (F & G), and four Flavobacterium clades (B, G-I) had comparably high minimal inhibitory concentrations (MICs) for 11/18 antimicrobials tested. Multiple clades in both genera exhibited MICs surpassing the established F. psychrophilum breakpoints for oxytetracycline and florfenicol, indicating potential resistance to two of the three antimicrobials approved for use in finfish aquaculture. Further work to investigate the virulence and antigenic diversity of these genetic groups will improve our understanding of flavobacterial disease, with applications for treatment and vaccination strategies.

Chryseobacterium demonstrates a diverse environmental presence and a significant pathogenic potential across various ecosystems. This clinical case showcases a rare instance of bacterial infection in a 75-year-old male with untreated diabetes and recurrent urinary tract infections (UTIs). The patient presented symptoms of abdominal pain, burning urination, fever, and an elevated eosinophil count. A subsequent urine culture identified a Chryseobacterium-related bacterium as the causative agent, exhibiting sensitivity to piperacillin/tazobactam, trimethoprim/sulfamethoxazole, and nitrofurantoin, which led to successful treatment using oral nitrofurantoin. Analysis of the 16S rRNA gene sequence of APV-1T revealed a close relationship of 98.2% similarity to Chryseobacterium gambrini strain 5-1St1aT (AM232810). Furthermore, comparative genome analysis, incorporating Average Nucleotide Identity (ANI), Digital DNA–DNA Hybridization (dDDH) values, and comprehensive phylogenetic assessments utilizing 16S rRNA gene sequences, core genes, and amino acid sequences of core proteins, highlighted the unique phylogenetic positioning of APV-1T within the Chryseobacterium genus. Distinct carbon utilization and assimilation patterns, along with major fatty acid content, set APV-1T apart from C. gambrini strain 5-1St1aT. These findings, encompassing phenotypic, genotypic, and chemotaxonomic characteristics, strongly support the proposal of a novel species named Chryseobacterium urinae sp. nov., with APV-1T designated as the type strain (= MCC 50690 = JCM 36476). Despite its successful treatment, the strain displayed resistance to multiple antibiotics. Genomic analysis further unveiled core-conserved genes, strain-specific clusters, and genes associated with antibiotic resistance and virulence. This report underscores the vital importance of elucidating susceptibility patterns of rare pathogens like Chryseobacterium, particularly in immunocompromised individuals. It advocates for further analyses to understand the functional significance of identified genes and their implications in treatment and pathogenesis. [ABSTRACT FROM AUTHOR]

An auxin-producing bacterial strain, CC-SYL302T, was isolated from paddy soil in Taiwan and identified using a polyphasic taxonomic approach. The cells were observed to be aerobic, non-motile, non-spore-forming rods, and tested positive for catalase and oxidase. Produced carotenoid but flexirubin-type pigments were absent. Optimal growth of strain CC-SYL302T was observed at 25 °C, pH 7.0, and with 2% (w/v) NaCl present. Based on analysis of 16S rRNA gene sequences, it was determined that strain CC-SYL302T belongs to the genus Flavobacterium of the Flavobacteriaceae family. The closest known relatives of this strain are F. tangerinum YIM 102701-2 T (with 93.3% similarity) and F. cucumis R2A45-3 T (with 93.1% similarity). Digital DNA-DNA hybridization (dDDH) values were calculated to assess the genetic distance between strain CC-SYL302T and its closest relatives, with mean values of 21.3% for F. tangerinum and 20.4% for F. cucumis. Strain CC-SYL302T exhibited the highest orthologous average nucleotide identity (OrthoANI) values with members of the Flavobacterium genus, ranging from 67.2 to 72.1% (n = 22). The dominating cellular fatty acids (> 5%) included iso-C14:0, iso-C15:0, iso-C16:0, iso-C15:0 3-OH, iso-C17:0 3-OH, C16:1 ω6c/C16:1 ω7c and C16:0 10-methyl/iso-C17:1 ω9c. The polar lipid profile consisted of phosphatidylethanolamine, an unidentified aminolipid, an unidentified aminophospholipid, and nine unidentified polar lipids. The genome (2.7 Mb) contained 33.6% GC content, and the major polyamines were putrescine and sym-homospermidine. Strain CC-SYL302T exhibits distinct phylogenetic, phenotypic, and chemotaxonomic characteristics, as well as unique results in comparative analysis of 16S rRNA gene sequence, OrthoANI, dDDH, and phylogenomic placement. Therefore, it is proposed that this strain represents a new species of the Flavobacterium genus, for which the name Flavobacterium agricola sp. nov. is proposed. The type strain is CC-SYL302T (= BCRC 81320 T = JCM 34764 T). [ABSTRACT FROM AUTHOR]

The Gram-strain-negative, facultative anaerobic, chemoheterotrophic, short-rod-shaped, non-motile, forming yellow colonies strain, designated F89T, was isolated from marine sediment of Xiaoshi Island, Weihai. Strain F89T grew at 15–37 °C (optimally at 28 °C), at pH 6.0–8.5 (optimally at pH 7.0) and in the presence of 1–5% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain F89T was related to the family Flavobacteriaceae. F89T had highest 16S rRNA gene sequence similarity to Maribacter cobaltidurans MCCC 1K03318T (93.3%). The predominant cellular fatty acids of F89T were iso-C15:0, iso-C15:0 G and Summed Feature 3. The main respiratory quinone of F89T was menaquinone 6 (MK-6), consistent with that observed for all related strains. The polar lipid profile of strain F89T contained phosphatidylethanolamine, two aminolipids and three unidentified polar lipids. The genomic DNA G + C content of strain F89T was 42.7%. Strain F89T encoded 121 glycoside hydrolases and was a potential polysaccharide degrading bacterium. Differential phenotypic and genotypic characteristics of the strain showed that F89T should be classified as a novel genus in Flavobacteriaceae, for which the name Cerina litoralis is proposed. The type strain is F89T (= MCCC 1H00510T = KCTC 92203T). [ABSTRACT FROM AUTHOR]

Elizabethkingia species are environmental bacteria associated with opportunistic infections in vulnerable populations. Traditionally, Elizabethkingia meningoseptica was considered the predominant pathogenic species. However, commercial identification systems have routinely misidentified Elizabethkingia anophelis as E. meningoseptica, leading to a mischaracterization of clinical strains and an underestimation of the role of E. anophelis in human disease. Elizabethkingia spp. harbor multidrug resistance (MDR) genes that pose challenges for treatment. Differentiation between Elizabethkingia spp. is particularly important due to differences in antimicrobial resistance (AMR) and epidemiological investigation. In this study, we describe a case of MDR E. anophelis isolated from the blood and lower respiratory tract of a patient who was successfully treated with minocycline. These isolates were initially misidentified by matrix assisted laser desorption ionization-time of flight as E. meningoseptica, whereas whole genome sequencing (WGS) confirmed the isolates as E. anophelis with the closest related strain being E. anophelis NUHP1, which was implicated in a 2012 outbreak in Singapore. Several AMR genes (blaBlaB, blaBlaGOB, blaCME, Sul2, erm(F), and catB) were identified by WGS, confirming the mechanisms for MDR. This case emphasizes the utility of WGS for correct speciation, elucidation of resistance genes, and relatedness to other outbreak strains. As E. anophelis is associated with a high mortality and has been found in hospital system sinks, WGS is critically important for determining strain relatedness and tracking outbreaks in the hospital setting.

ABSTRACT Flavobacteriaceae spp. are key players in global biogeochemical cycling and are known for their versatile carbohydrate and peptide catabolism. However, it is currently unknown whether secondary metabolism traits underlie their broad range of occurrence across the earth’s biomes. We examined 2,680 genomes to unveil an unprecedented phylogenetic signal dictating natural product biosynthesis diversification within the Flavobacteriaceae family. The distribution of secondary metabolite biosynthetic gene clusters (BGCs) across genomes usually follows macroevolutionary, genus-specific patterns. Noticeably, 88.6% of the observed BGCs were inferred to lead to the biosynthesis of likely novel natural products. We found an unanticipated, large diversity of taxon-specific BGCs encoding carotenoid and flexirubin pigments, the vast majority of which awaiting formal description. In particular, Aquimarina and Kordia spp. possessed large genomes, versatile catabolic traits, and a repertoire of BGCs possibly encoding drug-inspiring polyketides, non-ribosomal peptides, or post-translationally modified peptides. Using a machine learning approach (feature selection), we reveal that marine and non-marine Flavobacteriaceae genomes are differentially enriched in CAZymes and peptidases with distinct functionalities and molecular targets.IMPORTANCEThis is the most comprehensive study performed thus far on the biosynthetic potential within the Flavobacteriaceae family. Our findings reveal intertwined taxonomic and natural product biosynthesis diversification within the family. We posit that the carbohydrate, peptide, and secondary metabolism triad synergistically shaped the evolution of this keystone bacterial taxon, acting as major forces underpinning the broad host range and opportunistic-to-pathogenic behavior encompassed by species in the family. This study further breaks new ground for future research on select Flavobacteriaceae spp. as reservoirs of novel drug leads.

Objective: To investigate the clinical and epidemiological features and outcome of Chryseobacterium and Elizabethkingia spp. infections in children, together with antimicrobial susceptibilities. Methods: This retrospective study was conducted at a tertiary pediatric hospital in Turkey. All patients infected with Chryseobacterium/Elizabethkingia spp. among those presenting to Ankara City Hospital between March 2014 and March 2022 were included. Results: A total of 49 cases were included and 29 cases were identified as Elizabethkingia. The median age was 14 (0.2-185.0) months. The majority (89.8%) of these patients had an underlying disease, including malignancy (42.9%). Bacteremia (46.9%) and central line-associated bloodstream infection (28.6%) were the most common infections. The thirty-day all-cause mortality rate was 12.2%. The most commonly used antibiotics were ciprofloxacin and trimethoprim-sulfamethoxazole (TMP-SMX). Forty-five (91.8%) isolates were susceptible to ciprofloxacin, 44 (91.6%) to TMPSMX, and 21 (87.5%) to levofloxacin. Conclusions: Chryseobacterium and Elizabethkingia spp. are emergent, nosocomial pathogens and the majority of cases were older than the neonatal period. They were mainly seen in patients with long hospital stays, indwelling devices, and those who have received antibiotics within the last month, especially carbapenems. In addition, they were associated with bloodstream infection and malignancy. The most commonly useful antibiotics according to the resistance patterns were ciprofloxacin and TMP-SMX. [ABSTRACT FROM AUTHOR]

Two strains, 81s02T and 334s03T, were isolated from the sediment core near the hydrothermal field of southern Okinawa Trough. The cells of both strains were observed to be rod-shaped, non-gliding, Gram-staining negative, yellow-pigmented, facultatively anaerobic, catalase and oxidase positive, and showing optimum growth at 30 °C and pH 7.5. The strains 81s02T and 334s03T were able to tolerate up to 10% and 9% (w/v) NaCl concentration, respectively. Based on phylogenomic analysis, the average nucleotide identity (ANI) and the digital DNA-DNA hybridization (dDDH) values between the two strains and the nearest phylogenetic neighbors of the genus Muricauda were in range of 78.0–86.3% and 21.5–33.9%, respectively. The strains 81s02T and 334s03T shared 98.1% 16S rRNA gene sequence similarity to each other but were identified as two distinct species based on 81.4–81.5% ANIb, 85.5–85.6% ANIm and 25.4% dDDH values calculated using whole genome sequences. The strains 81s02T and 334s03T shared the highest 16S rRNA gene sequence similarity to M. lutimaris SMK-108T (98.7%) and M. aurea BC31-1-A7T (98.8%), respectively. The major fatty acid of strains 81s02T and 334s03T were identified similarly as iso-C15:0, iso-C17:0 3-OH and iso-C15:1 G, and the major polar lipids of the both strains consisted of phosphatidylethanolamine and two unidentified lipids. The strains contained MK-6 as their predominant menaquinone. The genomic G+C contents of strains 81s02T and 334s03T were determined to be 41.6 and 41.9 mol%, respectively. Based on the phylogenetic and phenotypic characteristics, both strains are considered to represent two novel species of the genus Muricauda, and the names Muricauda okinawensis sp. nov. and Muricauda yonaguniensis sp. nov. are proposed for strains 81s02T (=KCTC 92889T = MCCC 1K08502T) and 334s03T (=KCTC 92890T = MCCC 1K08503T). [ABSTRACT FROM AUTHOR]

Objective: To investigate the clinical and epidemiological features and outcome of Chryseobacterium and Elizabethkingia spp. infections in children, together with antimicrobial susceptibilities. Methods: This retrospective study was conducted at a tertiary pediatric hospital in Turkey. All patients infected with Chryseobacterium/Elizabethkingia spp. among those presenting to Ankara City Hospital between March 2014 and March 2022 were included. Results: A total of 49 cases were included and 29 cases were identified as Elizabethkingia. The median age was 14 (0.2-185.0) months. The majority (89.8%) of these patients had an underlying disease, including malignancy (42.9%). Bacteremia (46.9%) and central line-associated bloodstream infection (28.6%) were the most common infections. The thirty-day all-cause mortality rate was 12.2%. The most commonly used antibiotics were ciprofloxacin and trimethoprim-sulfamethoxazole (TMP-SMX). Forty-five (91.8%) isolates were susceptible to ciprofloxacin, 44 (91.6%) to TMP-SMX, and 21 (87.5%) to levofloxacin. Conclusions: Chryseobacterium and Elizabethkingia spp. are emergent, nosocomial pathogens and the majority of cases were older than the neonatal period. They were mainly seen in patients with long hospital stays, indwelling devices, and those who have received antibiotics within the last month, especially carbapenems. In addition, they were associated with bloodstream infection and malignancy. The most commonly useful antibiotics according to the resistance patterns were ciprofloxacin and TMP-SMX.

A Gram-stain negative, strictly aerobic, and rod-shaped bacterium, designated as strain L182T, was isolated from coastal sediment in Beihai, Guangxi Province, PR China. Colonies of strain L182T were yellow, 2 mm in diameter, round, opaque, smooth and convex after incubation on marine ager at 30 °C for 3 days. Cells were catalase-positive but oxidase-negative. Growth of strain L182T was observed at 4–40 °C (optimum, 25 °C), pH 5.5–10.0 (optimum, pH 5.5–8.0) and with 0–6% (w/v) NaCl (optimum, 0.5–4.0%). The G + C content based on the genome sequence was 36.0%. The only respiratory quinone was MK-6. The main polar lipids included phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid, one unidentified glycolipids, four unidentified aminolipids and six unidentified lipids. The major fatty acids (> 10%) were iso-C15:0, iso-C15:1 G and iso-C17:0 3-OH. The 16S rRNA gene sequence similarity between strain L182T and Aestuariibaculum suncheonense SC17T was 98.2%, and the similarities with other type strains of the genus Aestuariibaculum were 96.1–97.2%. The average nucleotide identity and in silicon DNA–DNA hybridization values between the strain L182T and its closely related Aestuariibaculum species were 80.8–85.2% and 22.0–29.5%. According to the above results, Aestuariibaculum lutulentum sp. nov. was proposed as a novel species. The type strain is L182T (= MCCC 1K08065T = KCTC 92530T). [ABSTRACT FROM AUTHOR]

The halophilic genus Joostella is one of the least-studied genera in the family of Flavobacteriaceae. So far, only two species were taxonomically identified with limited genomic analysis in the aspect of application has been reported. Joostella atrarenae M1-2T was previously isolated from a seashore sample and it is the second discovered species of the genus Joostella. In this project, the genome of J. atrarenae M1-2T was sequenced using NovaSeq 6000. The final assembled genome is comprised of 71 contigs, a total of 3,983,942 bp, a GC ratio of 33.2%, and encoded for 3,416 genes. The 16S rRNA gene sequence of J. atrarenae M1-2T shows 97.3% similarity against J. marina DSM 19592T. Genome-genome comparison between the two strains by ANI, dDDH, AAI, and POCP shows values of 80.8%, 23.3%, 83.4%, and 74.1% respectively. Pan-genome analysis shows that strain M1-2T and J. marina DSM 19592T shared a total of 248 core genes. Taken together, strain M-2T and J. marina DSM 19592T belong to the same genus but are two different species. CAZymes analysis revealed that strain M1-2T harbors 109 GHs, 40 GTs, 5 PLs, 9 CEs, and 6 AAs. Among these CAZymes, while 5 genes are related to cellulose degradation, 12 and 24 genes are found to encode for xylanolytic enzymes and other hemicellulases that involve majorly in the side chain removal of the lignocellulose structure, respectively. Furthermore, both the intracellular and extracellular crude extracts of strain M1-2T exhibited enzymatic activities against CMC, xylan, pNPG, and pNPX substrates, which corresponding to endoglucanase, xylanase, β-glucosidase, and β-xylosidase, respectively. Collectively, description of genome coupled with the enzyme assay results demonstrated that J. atrarenae M1-2T has a role in lignocellulosic biomass degradation, and the strain could be useful for lignocellulosic biorefining. [ABSTRACT FROM AUTHOR]

A novel bacterium designated RR4-40T was isolated from a biofilter of seawater recirculating aquaculture system in Busan, South Korea. Cells are strictly aerobic, Gram-negative, irregular short rod, non-motile, and oxidase- and catalase-negative. Growth was observed at 15–30°C, 0.5–6% NaCl (w/v), and pH 5.0–9.5. The strain grew optimally at 28°C, 3% salinity (w/v), and pH 8.5. The phylogenetic analysis based on 16S rRNA gene sequences showed that strain RR4-40T was most closely related to Marinirhabdus gelatinilytica NH83T (94.16% of 16S rRNA gene similarity) and formed a cluster with genera within the family Flavobacteriaceae. The values of the average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH), and average amino acid identity (AAI) between genomes of strain RR4-40T and M. gelatinilytica NH83T were 72.91, 18.2, and 76.84%, respectively, and the values against the strains in the other genera were lower than those. The major fatty acids were iso-C15:0 (31.34%), iso-C17:0 3-OH (13.65%), iso-C16:0 3-OH (10.61%), and iso-C15:1 G (10.38%). The polar lipids comprised phosphatidylglycerol, diphosphatidylglycerol, aminophospholipid, aminolipid, glycolipid, and sphingolipid. The major respiratory quinone was menaquinone-6 (MK-6) and the DNA G + C content of strain RR4-40T was 37.4 mol%. According to the polyphasic analysis, strain RR4-40T is considered to represent a novel genus within the family Flavobacteriaceae, for which the name Rasiella rasia gen. nov, sp. nov. is proposed. The type strain is RR4-40T (= KCTC 52650T = MCCC 1K04210T). [ABSTRACT FROM AUTHOR]

A Gram-negative, nonmotile, rod-shaped bacterium, designated strain CAU 1631T, was isolated from a mudflat sample in the Republic of Korea. Strain CAU 1631T grew optimally at 30 °C, pH 6.5, and 1% (w/v) NaCl solution. Phylogenetic analysis based on 16S rRNA gene sequencing and 92 core genes indicated that strain CAU 1631T is a member of the genus Muricauda and most closely related to Muricauda oceanensis 40DY170T and Muricauda lutimaris SMK-108T (98.1%, both). The draft genome was 3.4 Mb with 3064 protein-coding genes, and the DNA G + C content was 43.3 mol%. The major fatty acids were iso-C15:0, iso-C17:0 3-OH, and iso-C15:0 G, and the major polar lipid was phosphatidylethanolamine. The predominant respiratory quinone was MK-6. Based on the comprehensive taxonomic characterization, strain CAU 1631T is a novel species, for which the name Muricauda lutisoli sp. nov. has been proposed. The type strain is CAU 1631T (= KCTC 82456T = MCCC 1K06088T). [ABSTRACT FROM AUTHOR]

BACKGROUND This case report describes a case of a 25-year-old man who underwent a surgical procedure and was subsequently diagnosed with acute myeloid leukemia. Following his immediate admission to a specialized hospital unit for hematology and hemotherapy to receive chemotherapy, he was found to have a concurrent infection with multidrug-resistant Elizabethkingia meningoseptica as well as Enterococcus faecium. Both isolates are commonly associated with healthcare-associated infections. CASE REPORT The patient described in this report underwent an exploratory laparotomy, which is an invasive surgical procedure, and was subsequently diagnosed with acute myeloid leukemia following a biopsy. Chemotherapy was initiated immediately, during which the patient developed clinical signs and symptoms of infection. Blood cultures revealed the presence of Enterococcus faecium, while urine cultures identified Elizabethkingia meningoseptica. The VITEK-2 antibiogram for both bacteria revealed a multidrug resistance profile. E-test performed for glycopeptides indicated high-level resistance, with a minimum inhibitory concentration (MIC) exceeding 256 µg/mL. Prophylactic antibiotic therapy was initiated and subsequently adjusted according to the culture and antibiogram results. CONCLUSIONS Use of proper aseptic techniques during medical procedures is essential. Patients with severely compromised immunity undergoing numerous procedures require strict isolation measures to prevent infections, which can make the difference between life and death. Early laboratory identification of pathogenic clones and their antimicrobial resistance profiles is crucial for timely etiological diagnosis. This helps prevent the spread of infections and hospital infection outbreaks.

We performed chlorine inactivation experiments for Elizabethkingia anophelis and E. meningoseptica bacterial strains from clinical and environmental sources. Free chlorine concentration × contact time values <0.04 mg·min/L achieved 99.9% inactivation of Elizabethkingia species, indicating chlorine susceptibility. Measures to control biofilm producing pathogens in plumbing are needed to prevent Elizabethkingia bacterial infections.

Two strains, 81s02T and 334s03T, were isolated from the sediment core near the hydrothermal field of southern Okinawa Trough. The cells of both strains were observed to be rod-shaped, non-gliding, Gram-staining negative, yellow-pigmented, facultatively anaerobic, catalase and oxidase positive, and showing optimum growth at 30 °C and pH 7.5. The strains 81s02T and 334s03T were able to tolerate up to 10% and 9% (w/v) NaCl concentration, respectively. Based on phylogenomic analysis, the average nucleotide identity (ANI) and the digital DNA-DNA hybridization (dDDH) values between the two strains and the nearest phylogenetic neighbors of the genus Muricauda were in range of 78.0–86.3% and 21.5–33.9%, respectively. The strains 81s02T and 334s03T shared 98.1% 16S rRNA gene sequence similarity to each other but were identified as two distinct species based on 81.4–81.5% ANIb, 85.5–85.6% ANIm and 25.4% dDDH values calculated using whole genome sequences. The strains 81s02T and 334s03T shared the highest 16S rRNA gene sequence similarity to M. lutimaris SMK-108T (98.7%) and M. aurea BC31-1-A7T (98.8%), respectively. The major fatty acid of strains 81s02T and 334s03T were identified similarly as iso-C15:0, iso-C17:0 3-OH and iso-C15:1 G, and the major polar lipids of the both strains consisted of phosphatidylethanolamine and two unidentified lipids. The strains contained MK-6 as their predominant menaquinone. The genomic G+C contents of strains 81s02T and 334s03T were determined to be 41.6 and 41.9 mol%, respectively. Based on the phylogenetic and phenotypic characteristics, both strains are considered to represent two novel species of the genus Muricauda, and the names Muricauda okinawensis sp. nov. and Muricauda yonaguniensis sp. nov. are proposed for strains 81s02T (=KCTC 92889T = MCCC 1K08502T) and 334s03T (=KCTC 92890T = MCCC 1K08503T).

A Gram-negative, strictly aerobic, non-motile, rod-shaped bacterial strain CAU 1614T was isolated from a marine sediment sample collected in the Republic of Korea. Optimal growth of strain CAU 1614T proceeded at 30 °C, pH 7.0, and 2% (w/v) NaCl. 16S rRNA gene similarity was lower than 94.5% with genera Aureisphaera, Marinirhabdus, Aureitalea, Gilvibacter, Ulvibacter, and Jejudonia. The highest similarity was with Aureisphaera galaxeae 04OKA003-7T (94.5%). The major cellular fatty acids were iso-C15:0, iso-C16:0, iso-C15:1 G, iso-C16:0 3-OH, and iso-C17:0 3-OH and the predominant menaquinone was MK-6. The polar lipids were phosphatidylethanolamine, phosphoglycolipid, an unidentified lipid, two unidentified aminolipids, and an unidentified glycolipid. The draft genome of strain CAU 1614T was 3.9 Mb and DNA G+C content was 36.0 mol%. On the basis of the phenotypic, chemotaxonomic, and genomic data, strain CAU 1614T presents a novel genus in the family Flavobacteriaceae, for which the name Halomarinibacterium sedimenti gen. nov., sp. nov. is proposed. The type strain is CAU 1614T (= KCTC 82457T = MCCC 1K06083T). [ABSTRACT FROM AUTHOR]

Nitrogen frequently limits oceanic photosynthesis and the availability of inorganic nitrogen sources in the surface oceans is shifting with global change. We evaluated the potential for abrupt increases in inorganic N sources to induce cascading effects on dissolved organic matter (DOM) and microbial communities in the surface ocean. We collected water from 5 m depth in the central North Pacific and amended duplicate 20 liter polycarbonate carboys with nitrate or ammonium, tracking planktonic carbon fixation, DOM production, DOM composition and microbial community structure responses over 1 week relative to controls. Both nitrogen sources stimulated bulk phytoplankton, bacterial and DOM production and enriched Synechococcus and Flavobacteriaceae; ammonium enriched for oligotrophic Actinobacteria OM1 and Gammaproteobacteria KI89A clades while nitrate enriched Gammaproteobacteria SAR86, SAR92 and OM60 clades. DOM resulting from both N enrichments was more labile and stimulated growth of copiotrophic Gammaproteobacteria (Alteromonadaceae and Oceanospirillaceae) and Alphaproteobacteria (Rhodobacteraceae and Hyphomonadaceae) in weeklong dark incubations relative to controls. Our study illustrates how nitrogen pulses may have direct and cascading effects on DOM composition and microbial community dynamics in the open ocean.

Chryseobacterium bovis DSM 19482T (Hantsis-Zacharov et al., Int J Syst Evol Microbiol 58:1024-1028, 2008) is a Gram-negative, rod shaped, non-motile, facultative anaerobe, chemoorganotroph bacterium. C. bovis is a member of the Flavobacteriaceae, a family within the phylum Bacteroidetes. It was isolated when psychrotolerant bacterial communities in raw milk and their proteolytic and lipolytic traits were studied. Here we describe the features of this organism, together with the draft genome sequence and annotation. The DNA G + C content is 38.19%. The chromosome length is 3,346,045 bp. It encodes 3236 proteins and 105 RNA genes. The C. bovis genome is part of the Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes study.

Two Gram-stain-negative, aerobic, non-motile, and rod-shaped bacterial strains, designated SM1352T and A20T, were isolated from intertidal sediments collected from King George Island, Antarctic. They shared 99.8% 16S rRNA gene sequence similarity with each other and had the highest sequence similarity of 98.1% to type strain of Aureibaculum marinum but < 93.4% sequence similarity to those of other known bacterial species. The genomes of strains SM1352T and A20T consisted of 5,108,092 bp and 4,772,071 bp, respectively, with the G + C contents both being 32.0%. They respectively encoded 4360 (including 37 tRNAs and 6 rRNAs) and 4032 (including 36 tRNAs and 5 rRNAs) genes. In the phylogenetic trees based on 16S rRNA gene and single-copy orthologous clusters (OCs), both strains clustered with Aureibaculum marinum and together formed a separate branch within the family Flavobacteriaceae. The ANI and DDH values between the two strains and Aureibaculum marinum BH-SD17T were all below the thresholds for species delineation. The major cellular fatty acids (> 10%) of the two strains included iso-C15:0, iso-C15:1 G, iso-C17:0 3-OH. Their polar lipids predominantly included phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified aminolipid, and two unidentified lipids. Genomic comparison revealed that both strains possessed much more glycoside hydrolases and sulfatase-rich polysaccharide utilization loci (PULs) than Aureibaculum marinum BH-SD17T. Based on the above polyphasic evidences, strains SM1352T and A20T represent two novel species within the genus Aureibaculum, for which the names Aureibaculum luteum sp. nov. and Aureibaculum flavum sp. nov. are proposed. The type strains are SM1352T (= CCTCC AB 2014243 T = JCM 30335 T) and A20T (= CCTCC AB 2020370 T = KCTC 82503 T), respectively. [ABSTRACT FROM AUTHOR]

For many bacteria, motility is essential for survival, growth, virulence, biofilm formation and intra/interspecies interactions. Since natural environments differ, bacteria have evolved remarkable motility systems to adapt, including swimming in aqueous media, and swarming, twitching and gliding on solid and semi-solid surfaces. Although tremendous advances have been achieved in understanding swimming and swarming motilities powered by flagella, and twitching motility powered by Type IV pili, little is known about gliding motility. Bacterial gliders are a heterogeneous group containing diverse bacteria that utilize surface motilities that do not depend on traditional flagella or pili, but are powered by mechanisms that are less well understood. Recently, advances in our understanding of the molecular machineries for several gliding bacteria revealed the roles of modified ion channels, secretion systems and unique machinery for surface movements. These novel mechanisms provide rich source materials for studying the function and evolution of complex microbial nanomachines. In this review, we summarize recent findings made on the gliding mechanisms of the myxobacteria, flavobacteria and mycoplasmas.

Strains of the genus Gramella (family Flavobacteriacae, phylum Bacteroidetes) were isolated from marine habitats such as tidal flat sediments, coastal surface seawater and sea urchins. Flavobacteriaceae have been shown to be involved in the decomposition of plant and algal polysaccharides. However, the potential to decompose polysaccharides may differ tremendously even between species of the same genus. Gramella echinicola KMM 6050(T) (DSM 19838(T)) and Gramella portivictoriae UST040801-001(T) (DSM 23547(T)) have genomes of similar lengths, similar numbers of protein coding genes and RNA genes. Both genomes encode for a greater number of peptidases compared to 'G. forsetii'. In contrast to the genome of 'G. forsetii', both genomes comprised a smaller set of CAZymes. Seven polysaccharide utilization loci were identified in the genomes of DSM 19838(T) and DSM 23547(T). Both Gramella strains hydrolyzed starch, galactomannan, arabinoxylan and hydroxyethyl-cellulose, but not pectin, chitosan and cellulose (Avicel). Galactan and xylan were hydrolyzed by strain DSM 19838(T), whereas strain DSM 23547(T) hydrolyzed pachyman and carboxy-methyl cellulose. Conclusively, both Gramella type strains exhibit characteristic physiological, morphological and genomic differences that might be linked to their habitat. Furthermore, the identified enzymes mediating polysaccharide decomposition, are of biotechnological interest.

Flavobacterium suncheonense is a member of the family Flavobacteriaceae in the phylum Bacteroidetes. Strain GH29-5(T) (DSM 17707(T)) was isolated from greenhouse soil in Suncheon, South Korea. F. suncheonense GH29-5(T) is part of the G enomic E ncyclopedia of B acteria and A rchaea project. The 2,880,663 bp long draft genome consists of 54 scaffolds with 2739 protein-coding genes and 82 RNA genes. The genome of strain GH29-5(T) has 117 genes encoding peptidases but a small number of genes encoding carbohydrate active enzymes (51 CAZymes). Metallo and serine peptidases were found most frequently. Among CAZymes, eight glycoside hydrolase families, nine glycosyl transferase families, two carbohydrate binding module families and four carbohydrate esterase families were identified. Suprisingly, polysaccharides utilization loci (PULs) were not found in strain GH29-5(T). Based on the coherent physiological and genomic characteristics we suggest that F. suncheonense GH29-5(T) feeds rather on proteins than saccharides and lipids.

A Gram stain-negative, aerobic, rod-shaped, motile by gliding and yellow-orange-pigmented bacterium, designated strain 10Alg 115T, was isolated from the red alga Ahnfeltia tobuchiensis. The phylogenetic analysis based on 16S rRNA gene sequences placed the novel strain within the family Flavobacteriaceae, phylum Bacteroidetes. The nearest neighbor of the new isolate was Aureibaculum marinum KCTC 62204T with sequence similarity of 98.1%. The average nucleotide similarity and digital DNA–DNA hybridization values between the novel strain and Aureibaculum marinum KCTC 62204T were 80% and 22.3%, respectively. The prevalent fatty acids of strain 10Alg 115T were iso-C15:0, iso-C15:1 G, iso-C17:0 3-OH, iso-C16:0 3-OH and C15:0. The polar lipid profile consisted of phosphatidylethanolamine, two unidentified aminolipids and two unidentified lipids. The DNA G + C content of the type strain calculated from the whole-genome sequence was 32.2 mol%. A combination of the genotypic and phenotypic data showed that the algal isolate represents a novel species of the of genus Aureibaculum, for which the name Aureibaculum algae sp. nov. is proposed. The type strain is 10Alg 115T (= KCTC 62086T = KMM 6764T). [ABSTRACT FROM AUTHOR]

Certain members of the Actinobacteria and Proteobacteria are known to degrade polyethylene terephthalate (PET). Here, we describe the first functional PET-active enzymes from the Bacteroidetes phylum. Using a PETase-specific Hidden-Markov-Model- (HMM-) based search algorithm, we identified several PETase candidates from Flavobacteriaceae and Porphyromonadaceae. Among them, two promiscuous and cold-active esterases derived from Aequorivita sp. (PET27) and Kaistella jeonii (PET30) showed depolymerizing activity on polycaprolactone (PCL), amorphous PET foil and on the polyester polyurethane Impranil® DLN. PET27 is a 37.8 kDa enzyme that released an average of 174.4 nmol terephthalic acid (TPA) after 120 h at 30°C from a 7 mg PET foil platelet in a 200 μl reaction volume, 38-times more than PET30 (37.4 kDa) released under the same conditions. The crystal structure of PET30 without its C-terminal Por-domain (PET30ΔPorC) was solved at 2.1 Å and displays high structural similarity to the Is PETase. PET30 shows a Phe-Met-Tyr substrate binding motif, which seems to be a unique feature, as Is PETase, LCC and PET2 all contain Tyr-Met-Trp binding residues, while PET27 possesses a Phe-Met-Trp motif that is identical to Cut190. Microscopic analyses showed that K. jeonii cells are indeed able to bind on and colonize PET surfaces after a few days of incubation. Homologs of PET27 and PET30 were detected in metagenomes, predominantly aquatic habitats, encompassing a wide range of different global climate zones and suggesting a hitherto unknown influence of this bacterial phylum on man-made polymer degradation. [ABSTRACT FROM AUTHOR]

A Gram-stain-negative, aerobic, and yellow-pigmented bacterium, designated A3-108T, was isolated from seawater of the West Pacific Ocean. Cells were non-motile and rod-shaped, with carotenoid-type pigments. Strain A3-108T grew at pH 6.0–8.5 (optimum 6.5) and 15–40 °C (optimum 28 °C), in the presence of 0.5–10% (w/v) NaCl (optimum 1.0%). It possessed the ability to produce H2S. Based on the 16S rRNA gene analysis, strain A3-108T exhibited highest similarity with Aureisphaera salina A6D-50T (90.6%). Phylogenetic analysis shown that strain A3-108T affiliated with members of the family Flavobacteriaceae and represented an independent lineage. The principal fatty acids were iso-C15:0, iso-C17:0 3-OH, iso-C15:1 G, and summed feature 3 (C16:1ω7c and/or C16:1ω6c). The sole isoprenoid quinone was MK-6. The major polar lipids were phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified aminolipid and one unidentified lipid. The ANIb, in silico DDH and AAI values among the genomes of strain A3-108T and three reference strains were 67.3–71.1%, 18.7–22.1%, and 58.8–71.4%, respectively. The G + C content was 41.0%. Distinctness of the phylogenetic position as well as differentiating chemotaxonomic and other phenotypic traits revealed that strain A3-108T represented a novel genus and species of the family Flavobacteriaceae, for which the name Luteirhabdus pelagi gen. nov., sp. nov. is proposed (type strain, A3-108T = CGMCC 1.18821T = KCTC 82563T). [ABSTRACT FROM AUTHOR]

Abstract Background Members of the bacterial family Flavobacteriaceae are widely distributed in the marine environment and often found associated with algae, fish, detritus or marine invertebrates. Yet, little is known about the characteristics that drive their ubiquity in diverse ecological niches. Here, we provide an overview of functional traits common to taxonomically diverse members of the family Flavobacteriaceae from different environmental sources, with a focus on the Marine clade. We include seven newly sequenced marine sponge-derived strains that were also tested for gliding motility and antimicrobial activity. Results Comparative genomics revealed that genome similarities appeared to be correlated to 16S rRNA gene- and genome-based phylogeny, while differences were mostly associated with nutrient acquisition, such as carbohydrate metabolism and gliding motility. The high frequency and diversity of genes encoding polymer-degrading enzymes, often arranged in polysaccharide utilization loci (PULs), support the capacity of marine Flavobacteriaceae to utilize diverse carbon sources. Homologs of gliding proteins were widespread among all studied Flavobacteriaceae in contrast to members of other phyla, highlighting the particular presence of this feature within the Bacteroidetes. Notably, not all bacteria predicted to glide formed spreading colonies. Genome mining uncovered a diverse secondary metabolite biosynthesis arsenal of Flavobacteriaceae with high prevalence of gene clusters encoding pathways for the production of antimicrobial, antioxidant and cytotoxic compounds. Antimicrobial activity tests showed, however, that the phenotype differed from the genome-derived predictions for the seven tested strains. Conclusions Our study elucidates the functional repertoire of marine Flavobacteriaceae and highlights the need to combine genomic and experimental data while using the appropriate stimuli to unlock their uncharted metabolic potential.

A Gram-stain-negative, aerobic, non-spore-forming, nonmotile, rod-shaped, and yellow-pigmented bacterium, designated strain JXAS1 T , was isolated from a freshwater sample collected from Poyang Lake in China. Phylogenetic analysis based on 16S rRNA gene sequence revealed that the isolate belonged to the genus Flavobacterium , being closest to Flavobacterium pectinovorum DSM 6368 T (98.61 %). The genome size of strain JXAS1 T was 4.66 Mb with DNA G+C content 35.7 mol%. The average nucleotide identity and in silico DNA-DNA hybridization values between strain JXAS1 T and its closest relatives were below the threshold values of 95 and 70 %, respectively. The strain contained menaquinone 6 (MK-6) as the predominant menaquinone and the major polar lipids were phosphatidylethanolamine, one unidentified glycolipid, and one unidentified polar lipid. The major fatty acids (>5 %) were iso-C 15 : 0 , summed feature 3 (C 16 : 1  ω 7 c and/or C 16 : 1  ω 6 c ), C 15 : 0 , iso-C 17 : 0 3OH, iso-C 15 : 0 3OH, and summed feature 9 (iso-C 17 : 1  ω 9 c and/or 10-methyl C 16 : 0 ). Based on phylogenetic, genotypic, and phenotypic evidence, the isolated strain represents a new species in the genus Flavobacterium , and the name Flavobacterium poyangense is proposed. The type strain is JXAS1 T (=GDMCC 1.1378 T =KCTC 62719 T ).

A bacterial strain, designated M625T, was isolated from the surface of a marine red alga. Phylogenetic trees were reconstructed based on the 16S rRNA gene and RpoB protein sequences, which indicated that the strain belongs to the genus Aquimarina within the family Flavobacteriaceae. Strain M625T showed high sequence similarities to A. aggregata RZW4-3-2 T (95.7%), A. seongsanensis CBA3208T (95.3%) and A. versatilis CBA3207T (95.0%). The AAI and POCP values between strain M625T and A. muelleri DSM 19832 T were 71.8% and 57.9% respectively. The dDDH and ANI values between strain M625T and A. aggregata were 19.5% and 74.6% respectively. The strain was Gram-stain negative, strictly aerobic, non-motile and long rod-shaped, and positive for hydrolysis of starch, cellulose, alginate, DNA and Tween 20. The dominant respiratory quinone was MK-6. The major fatty acids were iso-C15:0, iso-C17:0 3-OH, and iso-C15:1 G, and the polar lipids consisted of phosphatidylethanolamine, one unidentified phospholipid, two unidentified aminolipids, and seven unidentified lipids. Based on the polyphasic comparisons, strain M625T is proposed to represent a novel species within the genus Aquimarina, for which the name Aquimarina algicola sp. nov. (type strain M625T = MCCC 1H00399T = KCTC 72685 T) was proposed. [ABSTRACT FROM AUTHOR]

A Gram stain-negative, aerobic, motile by gliding, rod-shaped bacterial strain CAU 1569T was isolated from marine sediment on Shido Island in Incheon. It grew at 20–37 °C (optimum, 30 °C), pH 6.0–9.0 (optimum, 7.0), 2–6% NaCl (w/v) (optimum, 2%). Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain CAU 1569T formed a distinct lineage with only the type strain of Snuella. Strain CAU 1569T showed high similarity to S. lapsa KACC 14152T (95.8%), Mariniflexile gromovii KMM KCTC 12570T, Aestuariibaculum marinum KCTC 52521T (95.4%), A. suncheonense KACC 16186T (94.6%) and Yeosuana aromativorans KCCM 42019T (94.4%). The genome contained 57 contigs, 3,437 protein-coding gene, 3 rRNAs (5, 16, and 23S), 43 tRNAs, and with a 35.7 mol% G + C content. The DDH value between strain CAU 1569T and S. lapsa KACC 14152T was 39.4 ± 0.6%. The only isoprenoid quinone was menaquinone 6 (MK-6). The major fatty acids were iso-C15:0, C15:1-iso G, and C17:0 iso 3-OH. Strain CAU 1569T contained diphosphatidylglycerol, aminoglycolipid, unidentified aminolipid, and three unidentified lipids. Based on phylogenetic, genomic, physiologic, and chemotaxonomic characterizations, strain CAU 1569T represents a novel Snuella species, which the name Snuella sedimenti sp. nov. is proposed. The type of strain is CAU 1569T (= KCTC 82409T = MCCC 1K05670T). [ABSTRACT FROM AUTHOR]

A Gram-stain-negative, yellow, strictly aerobic, non-flagellated, gliding, rod-shaped bacterial strain, was isolated from costal sediment, designated as F6074T. The strain F6074T grows optimally at 30 °C, pH 7.5, and 3.0% (w/v) NaCl. Cells of strain F6074T are 0.2–0.5 µm wide and 1.0–2.0 µm long. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain F6074T belonged to the genus Gelidibacter, with the highest sequence similarity to Gelidibacter japonicus JCM 31967T (98.0%), followed by G. flavus JCM 31135T (97.7%), and similarity between strain F6074T and the type species G. algens DSM 12408T was 96.0%. Genome sequencing results revealed a genome size of 47,07,621 bp. The DNA G + C content was 37.8 mol%. The ANI and dDDH values between strain F6074T and G. japonicus JCM 31967T were 83.9 and 27.8%, the values between strain F6074T and G. algens DSM 12408T were 77.5% and 31.5%, and the values between strain F6074T and G. flavus JCM 31135T were 84.3 and 27.9%, respectively. The predominant quinone was MK-6 and the major fatty acids were iso-C15:0, iso-C15:1G, iso-C17:0 3-OH, anteiso-C15:0 and summed feature 3. The polar lipids were consisted of phosphatidylethanolamine (PE), two unidentified aminolipids (AL) and three unidentified lipids (L1, L2, L3). Based on the phenotypic, phylogenetic and chemotaxonomic data, strain F6074T was considered to represent a novel species of the genus Gelidibacter, for which the name Gelidibacter maritimus sp. nov., is proposed. The type strain is F6074T (MCCC 1H00427T = KCTC 72942T). [ABSTRACT FROM AUTHOR]

A novel bright-yellow pigmented bacterial strain SM2-FT was isolated from a mangrove sediment collected at the mangrove coast of Luoyang estuary, Quanzhou, China. Strain SM2-FT was Gram-stain-negative, catalase-weak positive, oxidase-positive, rod-shaped, non-flagellated and non-motile. Growth of strain SM2-FT was observed at 20–40 °C (optimum, 30 °C), pH 6.0–8.0 (optimum, pH 7.0) and in the presence of 1.0–4.0% NaCl (optimum, 2.0% NaCl). Flexirubin-pigment was absent, and carotenoid-pigment was present. Phylogenetic analysis of 16S rRNA gene sequence placed strain SM2-FT into the family Flavobacteriaceae and shared the maximum sequence similarity with Aequorivita soesokkakensis RSSK-12 T of 92.5%. Whole genomic comparison between strain SM2-FT and close relatives suggested a novel species of a novel genus. The predominant quinone of strain SM2-FT was menaquinone (MK)-6. The major fatty acids (> 10%) comprised iso-C15:1 G (32.4%) and iso-C15:0 (29.1%). The polar lipid profile consisted of phosphatidylethanolamine, two unidentified aminolipids and four unidentified lipids. The complete genome size was 4,094,245 bp with DNA G + C content of 36.0 mol%. Based on the data of polyphasic study, strain SM2-FT was considered to represent a novel species of a novel genus, for which the name Aegicerativicinus sediminis gen. nov., sp. nov., was proposed. The type strain was SM2-FT (= MCCC 1K04383T = KCTC 82361 T). [ABSTRACT FROM AUTHOR]

In our previous study, it was shown that Riemerella anatipestifer , a Gram-negative bacterium, is naturally competent, but the genes involved in the process of natural transformation remain largely unknown. In this study, a random transposon mutant library was constructed using the R. anatipestifer ATCC11845 strain to screen for the genes involved in natural transformation. Among the 3000 insertion mutants, nine mutants had completely lost the ability of natural transformation, and 14 mutants showed a significant decrease in natural transformation frequency. We found that the genes RA0C_RS04920 , RA0C_RS04915 , RA0C_RS02645 , RA0C_RS04895 , RA0C_RS05130 , RA0C_RS05105 , RA0C_RS09020 , and RA0C_RS04870 are essential for the occurrence of natural transformation in R. anatipestifer ATCC11845. In particular, RA0C_RS04895 , RA0C_RS05130 , RA0C_RS05105 , and RA0C_RS04870 were putatively annotated as ComEC, DprA, ComF, and RecA proteins, respectively, in the NCBI database. However, RA0C_RS02645, RA0C_RS04920, RA0C_RS04915, and RA0C_RS09020 were annotated as proteins with unknown function, with no homology to any well-characterized natural transformation machinery proteins. The homologs of these proteins are mainly distributed in the members of Flavobacteriaceae. Taken together, our results suggest that R. anatipestifer encodes a unique natural transformation machinery. [ABSTRACT FROM AUTHOR]

A bacterial strain designated KDG-16 T is isolated from a freshwater waterfall in Taiwan and characterized to determine its taxonomic affiliation. Cells of strain KDG-16 T are Gram-stain-negative, strictly aerobic, motile by gliding, rod-shaped and form light yellow colonies. Optimal growth occurs at 20–25 °C, pH 6–7, and with 0% NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set reveal that strain KDG-16 T is affiliated with species in the genus Flavobacterium. Analysis of 16S rRNA gene sequences shows that strain KDG-16 T shares the highest similarity with Flavobacterium terrigena DSM 17934 T (97.7%). The average nucleotide identity, average amino acid identity and digital DNA–DNA hybridization values between strain KDG-16 T and the closely related Flavobacterium species are below the cut-off values of 95–96, 90 and 70%, respectively, used for species demarcation. Strain KDG-16 T contains iso-C15:0, iso-C15:1 G and iso-C17:0 3-OH as the predominant fatty acids. The polar lipid profile consists of phosphatidylethanolamine, one uncharacterized aminophospholipid, one uncharacterized phospholipid, two uncharacterized aminolipids and two uncharacterized lipids. The major polyamine is homospermidine. The major isoprenoid quinone is MK-6. Genomic DNA G + C content of strain KDG-16 T is 31.6%. Based on the polyphasic taxonomic data obtained, strain KDG-16 T is considered to represent a novel species in the genus Flavobacterium, for which the name Flavobacterium difficile sp. nov. is proposed. The type strain is KDG-16 T (= BCRC 81194 T = LMG 31332 T). [ABSTRACT FROM AUTHOR]

A taxonomic investigation using a polyphasic method was conducted to identify a novel marine flavobacterium, designated as DJ-13T, isolated from the hard coral Acropora sp. collected at Okinawa, Japan. Bacterial cells were Gram-stain-negative, yellow-colored, strictly aerobic, rod-shaped, catalase- and oxidase-positive, non-motile, and chemoorganoheterotrophic. The novel isolate grew at NaCl concentrations of 0.5–7%, pH 6.5–9.0, and 15–37 °C. A phylogenetic study on the basis of the 16S rRNA gene sequence revealed that strain DJ-13T belongs to the family Flavobacteriaceae and that it shared the greatest sequence similarity (95.9%) with Croceivirga lutea CSW06T. Strain DJ-13T comprised iso-C17:0 3-OH, iso-C15:0, and iso-C15:1 G as the main (> 10%) cellular fatty acids. Menaquinone-6 (MK-6) was the only respiratory quinone. The assembled draft genome size of strain DJ-13T was 3.71 Mbp with G + C content of 38.7 mol%. The average nucleotide identity (ANI), digital DNA–DNA hybridization (dDDH), and average amino acid identity (AAI) values of DJ-13T and the species of the genus Croceivirga were found to be 74.9–75.5%, 13.4–14.7%, and 68.2–72.4%, respectively. Strain DJ-13T contained phosphatidylethanolamine, two unidentified aminolipids, and five unidentified lipids as polar lipids. From the polyphasic taxonomic results presented, the strain is considered to represent a novel species of the genus Croceivirga for which the name Croceivirga thetidis sp. nov. is proposed. The type strain of C. thetidis sp. nov. is DJ-13T (= KCTC 72790T = NBRC 114252T). [ABSTRACT FROM AUTHOR]

Flavobacterium rivuli Ali et al. 2009 emend. Dong et al. 2013 is one of about 100 species in the genus Flavobacterium (family Flavobacteriacae, phylum Bacteroidetes) with a validly published name, and has been isolated from the spring of a hard water rivulet in Northern Germany. Including all type strains of the genus Myroides and Flavobacterium into the 16S rRNA gene sequence phylogeny revealed a clustering of members of the genus Myroides as a monophyletic group within the genus Flavobacterium. Furthermore, F. rivuli WB 3.3-2(T) and its next relatives seem more closely related to the genus Myroides than to the type species of the genus Flavobacterium, F. aquatile. The 4,489,248 bp long genome with its 3,391 protein-coding and 65 RNA genes is part of the G enomic E ncyclopedia of B acteria and A rchaea project. The genome of F. rivuli has almost as many genes encoding carbohydrate active enzymes (151 CAZymes) as genes encoding peptidases (177). Peptidases comprised mostly metallo (M) and serine (S) peptidases. Among CAZymes, 30 glycoside hydrolase families, 10 glycosyl transferase families, 7 carbohydrate binding module families and 7 carbohydrate esterase families were identified. Furthermore, we found four polysaccharide utilization loci (PUL) and one large CAZy rich gene cluster that might enable strain WB 3.3-2(T) to decompose plant and algae derived polysaccharides. Based on these results we propose F. rivuli as an interesting candidate for further physiological studies and the role of Bacteroidetes in the decomposition of complex polymers in the environment.

In our previous study, it was shown that Riemerella anatipestifer, a Gram-negative bacterium, is naturally competent, but the genes involved in the process of natural transformation remain largely unknown. In this study, a random transposon mutant library was constructed using the R. anatipestifer ATCC11845 strain to screen for the genes involved in natural transformation. Among the 3000 insertion mutants, nine mutants had completely lost the ability of natural transformation, and 14 mutants showed a significant decrease in natural transformation frequency. We found that the genes RA0C_RS04920, RA0C_RS04915, RA0C_RS02645, RA0C_RS04895, RA0C_RS05130, RA0C_RS05105, RA0C_RS09020, and RA0C_RS04870 are essential for the occurrence of natural transformation in R. anatipestifer ATCC11845. In particular, RA0C_RS04895, RA0C_RS05130, RA0C_RS05105, and RA0C_RS04870 were putatively annotated as ComEC, DprA, ComF, and RecA proteins, respectively, in the NCBI database. However, RA0C_RS02645, RA0C_RS04920, RA0C_RS04915, and RA0C_RS09020 were annotated as proteins with unknown function, with no homology to any well-characterized natural transformation machinery proteins. The homologs of these proteins are mainly distributed in the members of Flavobacteriaceae. Taken together, our results suggest that R. anatipestifer encodes a unique natural transformation machinery.

A group of microbial retinal proteins most closely related to the proton pump xanthorhodopsin has a novel sequence motif and a novel function. Instead of, or in addition to, proton transport, they perform light-driven sodium ion transport, as reported for one representative of this group (KR2) from Krokinobacter. In this paper, we examine a similar protein, GLR from Gillisia limnaea, expressed in Escherichia coli, which shares some properties with KR2 but transports only Na(+). The absorption spectrum of GLR is insensitive to Na(+) at concentrations of ≤3 M. However, very low concentrations of Na(+) cause profound differences in the decay and rise time of photocycle intermediates, consistent with a switch from a "Na(+)-independent" to a "Na(+)-dependent" photocycle (or photocycle branch) at ∼60 μM Na(+). The rates of photocycle steps in the latter, but not the former, are linearly dependent on Na(+) concentration. This suggests that a high-affinity Na(+) binding site is created transiently after photoexcitation, and entry of Na(+) from the bulk to this site redirects the course of events in the remainder of the cycle. A greater concentration of Na(+) is needed for switching the reaction path at lower pH. The data suggest therefore competition between H(+) and Na(+) to determine the two alternative pathways. The idea that a Na(+) binding site can be created at the Schiff base counterion is supported by the finding that upon perturbation of this region in the D251E mutant, Na(+) binds without photoexcitation. Binding of Na(+) to the mutant shifts the chromophore maximum to the red like that of H(+), which occurs in the photocycle of the wild type.