Phylogenomics and molecular signatures for the order Neisseriales: proposal for division of the order Neisseriales into the emended family Neisseriaceae and Chromobacteriaceae fam. nov

Partial genomic characterization of Chromobacterium piscinae from India reveals multi drug resistance

Species of genus Chromobacterium have been isolated from diverse geographical settings, which exhibits significant metabolic flexibility as well as biotechnological and pathogenic properties. This study describes the isolation, characterization, draft assembly, and detailed sequence analysis of Chromobacterium piscinae strain W1B-CG-NIBSM isolated from water samples from multi use community pond. The organism was characterized by biochemical tests, Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI TOF-MS) and partial genome sequencing. The partial genomic data of Chromobacterium pisciane isolate W1B NIBSM strain was submitted to GenBank with Bio project number PRJNA803347 and accession no CP092474. An integrated genome analysis of Chromobacterium piscinae has been accomplished with PATRIC which indicates good quality genome. DNA sequencing using the illumina HiSeq 4000 system generated total length of 4,155,481 bp with 63 contig with G + C content is 62.69%. This partial genome contains 4,126 protein-coding sequences (CDS), 27 repeats region and 78 transfer RNA (tRNA) genes as well as 3 ribosomal RNA (rRNA) genes. The genomic annotation of Chromobacterium W1B depicts 2,925 proteins with functional assignments and 1201 hypothetical proteins. A repertoire of specialty genes implicated in antibiotic resistance (45 genes), drug target (6 genes), Transporter (3 genes) and virulence factor (10 genes). The genomic analysis reveals the adaptability, displays metabolic varied pathways and shows specific structural complex and various virulence factors which makes this strain multi drug resistant. The isolate was found to be highly resistant to β-lactam antibiotics whereas it showed sensitivity towards aminoglycosides and fluoroquinolone antibiotics. Hence, the recovery of Chromobacterium piscinae from community pond evidenced for uncertain hidden source of public health hazard. To the best of authors knowledge this is first report of isolation and genomic description of C. piscinae from India.

Phylogenomic analysis of the understudied Neisseriaceae species reveals a poly- and paraphyletic Kingella genus

IMPORTANCE

Understanding the evolutionary relationships between the species in the Neisseriaceae family has been a persistent challenge in bacterial systematics due to high recombination rates in these species. Previous studies of this family have focused on Neisseria meningitidis and N. gonorrhoeae. However, previously understudied Neisseriaceae species are gaining new attention, with Kingella kingae now recognized as a common human pathogen and with Alysiella and Simonsiella being unique in the bacterial world as multicellular organisms. A better understanding of the genomic evolution of the Neisseriaceae can lead to the identification of specific genes and traits that underlie the remarkable diversity of this family.

Culture-independent analyses of carrion beetle (Coleoptera: Silphidae) secretion bacterial communities

IMPORTANCE

The manuscript explores the secretion bacterial community of carrion and burying beetles of the central plains of North America. A core secretion microbiome of 11 genera is identified. The host subfamily, secretion type, and collection locality significantly affects the secretion microbiome. Future culture-dependent studies from silphid secretions may identify novel antimicrobials and nontoxic compounds that can act as meat preservatives or sources for antimicrobials.

Silvimonas soli sp. nov., a new member of Chromobacteriaceae isolated from soil in Norrbyskär island, Sweden

A novel bacterial species is described that was isolated from the soil of Norrbyskär island (Sweden). This Gram-negative, facultatively anaerobic and motile rod, designated 17-6T, was classified in the family Chromobacteriaceae, class Betaproteobacteria, and further characterized by a polyphasic approach. Comparative 16S rRNA gene analysis revealed the potential species novelty of the strain, with Silvimonas terrae (98.20 % similarity) and Silvimonas amylolytica (98.13 %) being its closest type strains. The phylogenetic novelty of the isolate at the level of species was confirmed using phylogenetic analyses based on the whole genome: average nucleotide identity values ranged from 79 to 81 %, average amino acid identity values from 75 to 81 % and percentage of conserved proteins values from 69-81 % with the members of genera Silvimonas and Amantichitinum. On the basis of phenotypic, phylogenetic, functional and genotypic analyses, we propose the isolate as the type strain of a novel species within the genus Silvimonas with the designation Silvimonas soli 17-6T (=DSM 115342T=CCM 9308T).

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.

Kingella pumchi sp. nov., an organism isolated from human vertebral puncture tissue

A Gram-negative, non-motile rod and strictly aerobic bacterium, designated as 18B16333^T, was isolated from vertebral puncture tissue of a patient at Peking union medical college hospital in China. Growth occurred in NaCl concentrations of 0-1% (w/v) (optimum growth at 0% NaCl), at temperatures of 25-40 °C (optimum growth at 37 °C) and at pH 6.0-9.0 (optimum growth at pH 8.0). Diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine were the predominant polar lipids, and the major fatty acids were C_16:0, C_18:1 ω7c/C_18:1 ω6c and C_16:1 ω7c/C_16:1 ω6c. Phylogenetic analysis based on 16S rRNA gene sequence comparisons indicated that strain 18B16333^T was most closely related to Kingella potus CCUG 49773 ^T (97.3%, 16S rRNA gene sequence identity) and Neisseria bacilliformis CCUG 50858 ^T (96.8%). The ANI values between strain 18B16333^T and the type strains K. potus CCUG 49773 ^T, N. bacilliformis CCUG 50858 ^T, Kingella kingae CCUG 352 ^T and Neisseria gonorrhoeae CCUG 26876 ^T were 77.3%, 79.1%, 72.1% and 75.4%, respectively. The dDDH values between strain 18B16333^T and the four reference strains mentioned above were 24.8%, 26.9%, 24.2% and 20.7%. Further core gene analysis distinctively clustered strain 18B16333^T with four Kingella species but not with Neisseria species. Based on the phenotypic, chemotaxonomic, and phylogenetic properties, strain 18B16333^T represents a novel species of the genus Kingella, for which the name Kingella pumchi sp. nov. is proposed. The type strain is Kingella pumchi 18B16333^T (= CICC 24913 ^T = CCUG 75125 ^T).

Evolution of longitudinal division in multicellular bacteria of the Neisseriaceae family

Rod-shaped bacteria typically elongate and divide by transverse fission. However, several bacterial species can form rod-shaped cells that divide longitudinally. Here, we study the evolution of cell shape and division mode within the family Neisseriaceae, which includes Gram-negative coccoid and rod-shaped species. In particular, bacteria of the genera Alysiella, Simonsiella and Conchiformibius, which can be found in the oral cavity of mammals, are multicellular and divide longitudinally. We use comparative genomics and ultrastructural microscopy to infer that longitudinal division within Neisseriaceae evolved from a rod-shaped ancestor. In multicellular longitudinally-dividing species, neighbouring cells within multicellular filaments are attached by their lateral peptidoglycan. In these bacteria, peptidoglycan insertion does not appear concentric, i.e. from the cell periphery to its centre, but as a medial sheet guillotining each cell. Finally, we identify genes and alleles associated with multicellularity and longitudinal division, including the acquisition of amidase-encoding gene amiC2, and amino acid changes in proteins including MreB and FtsA. Introduction of amiC2 and allelic substitution of mreB in a rod-shaped species that divides by transverse fission results in shorter cells with longer septa. Our work sheds light on the evolution of multicellularity and longitudinal division in bacteria, and suggests that members of the Neisseriaceae family may be good models to study these processes due to their morphological plasticity and genetic tractability.

Rod-shaped bacteria typically elongate and divide by transverse fission, but a few species are known to divide longitudinally. Here, the authors use genomic, phylogenetic and microscopy techniques to shed light on the evolution of cell shape, multicellularity and division mode within the family Neisseriaceae.

Wielerella bovis gen. nov., sp. nov. a member of the family Neisseriaceae associated with bovine endocarditis

Seven bacterial strains isolated from bovine endocarditis in six animals from different geographic regions were investigated in a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA gene sequences placed all seven isolates on a distinct, monophyletic cluster in the family Neisseriaceae with closest similarity to type strains of Alysiella filiformis (97.06 %) and Kingella kingae (96.34 %). Whole genome sequence analysis of isolates confirmed their species status, with an average nucleotide identity >96 % between isolates and <80 % to other type species of genera of Neisseriaceae while digital DNA–DNA hybridization values were >80 % and<18 %, respectively. The DNA G+C content was 42.5–43.0 mol%. Whole genome sequence based phylogeny showed the isolates being monophyletic and separated from established genera, thereby forming a new genus within the family Neisseriaceae . Similarly, analysis of MALDI-TOF MS reference spectra clustered the isolates close together and clearly separated from other genera, making this the method of choice for identification. Biochemical markers based on classical as well as commercial identification schemes allowed separation from closely related Neisseriaceae genera, even though the new taxon is biochemically not very active. Major fatty acids are C12 : 0, C14 : 0 and C16 : 0. The major quinone is ubiquinone Q-8. In the polar lipid profile, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phospholipid were predominant. We propose the novel genus Wielerella with the type species Wielerella bovis gen. nov., sp. nov. The type strain is CCUG 44465T (=DSM 113289T=JF 2483T) isolated post mortem from a cow with endocarditis in Switzerland.

Fresh Rumen Liquid Inoculant Enhances the Rumen Microbial Community Establishment in Pre-weaned Dairy Calves

The development of the functional rumen in calves involves a complex interplay between the host and host-related microbiome. Attempts to modulate rumen microbial community establishment may therefore have an impact on weaning success, calf health, and animal performance later in life. In this experiment, we aimed to elucidate how rumen liquid inoculum from an adult cow, provided to calves during the pre-weaning period, influences the establishment of rumen bacterial, archaeal, fungal, and ciliate protozoan communities in monozygotic twin calves (n = 6 pairs). The calves were divided into treatment (T-group) and control (C-group) groups, where the T-group received fresh rumen liquid as an oral inoculum during a 2-8-week period. The C-group was not inoculated. The rumen microbial community composition was determined using bacterial and archaeal 16S ribosomal RNA (rRNA) gene, protozoal 18S rRNA gene, and fungal ITS1 region amplicon sequencing. Animal weight gain and feed intake were monitored throughout the experiment. The T-group tended to have a higher concentrate intake (Treatment: p < 0.08) and had a significantly higher weekly weight gain (Treatment: p < 0.05), but no significant difference in volatile fatty acid concentrations between the groups was observed. In the T-group, the inoculum stimulated the earlier establishment of mature rumen-related bacterial taxa, affecting significant differences between the groups until 6 weeks of age. The inoculum also increased the archaeal operational taxonomic unit (OTU) diversity (Treatment: p < 0.05) but did not affect the archaeal quantity. Archaeal communities differed significantly between groups until week 4 (p = 0.02). Due to the inoculum, ciliate protozoa were detected in the T-group in week 2, while the C-group remained defaunated until 6 weeks of age. In week 8, Eremoplastron dilobum was the dominant ciliate protozoa in the C-group and Isotricha sp. in the T-group, respectively. The Shannon diversity of rumen anaerobic fungi reduced with age (Week: p < 0.01), and community establishment was influenced by a change of diet and potential interaction with other rumen microorganisms. Our results indicate that an adult cow rumen liquid inoculum enhanced the maturation of bacterial and archaeal communities in pre-weaning calves' rumen, whereas its effect on eukaryotic communities was less clear and requires further investigation.

Thainema gen. nov. (Leptolyngbyaceae, Synechococcales): A new genus of simple trichal cyanobacteria isolated from a solar saltern environment in Thailand

Simple trichal types constitute a group of cyanobacteria with an abundance of novel, often cryptic taxa. Here, we investigated material collected from wet surface-soil in a saline environment in Petchaburi Province, central Thailand. A morphological comparison of the isolated strain with similar known species, as well as its phylogenetic and species delimitation analyses based on the combined datasets of other related organisms, especially simple trichal cyanobacteria, revealed that the material of this study represented an independent taxon. Using a multifaceted method, we propose that this material represents a new genus, Thainema gen. nov., belonging to the family Leptolyngbyaceae, with the type species Thainema salinarum sp. nov. This novel taxon shares similar ecological habitats with strains previously placed in the same lineage.

A case of pyogenic spondylitis caused by Paludibacteriumpurpuratum

Paludibacterium purpuratum was first reported as a Gram stain-negative, curved, rod-shaped bacterium isolated from a wetland soil in 2016. We report the first case in the world, to our knowledge, of pyogenic spondylitis caused by P. purpuratum. The patient, a 78-year-old man, came to our hospital complaining chiefly of fever and pain in the left knee. He did not complain of low back pain at the time of examination, although increased low back pain was observed for the first time after admission. Magnetic resonance imaging of the lumbar spine and percutaneous needle biopsy at the L2/L3 disc level were performed, and pyogenic spondylitis was diagnosed. A curved, Gram stain-negative rod was detected in the blood culture obtained at admission that was identified as P. purpuratum by 16S rDNA gene analysis.

Phylogenomics and molecular signatures support division of the order Neisseriales into emended families Neisseriaceae and Chromobacteriaceae and three new families Aquaspirillaceae fam. nov., Chitinibacteraceae fam. nov., and Leeiaceae fam. nov

The order Neisseriales contains 37 genera harboring 122 species with validly published names, which are placed into two families, Neisseriaceae and Chromobacteriaceae. Genome sequences are now available for 35 of the 37 Neisseriales genera for reliably determining their evolutionary relationships and taxonomy. We report here comprehensive phylogenomic and comparative analyses on protein sequences from 110 Neisseriales genomes plus 3 Chitinimonas genomes using multiple approaches. In a phylogenomic tree based on 596 core proteins, Neisseriales species formed 5 strongly supported clades. In addition to the clades for Neisseriaceae and Chromobacteriaceae families, three novel species clades designated as the "Chitinibacteraceae", "Aquaspirillaceae", and "Leeiaceae" were observed. The genus Chitinimonas grouped reliably with members of the "Chitinibacteraceae" clade. The major clades within the order Neisseriales can also be distinguished based on average amino acid identity analysis. In parallel, our comparative genomic studies have identified 30 conserved signature indels (CSIs) that are specific for members of the order Neisseriales or its five main clades. One of these CSIs is uniquely shared by all Neisseriales, whereas 8, 4, 9, 3 and 5 CSIs are distinctive characteristics of the Neisseriaceae, Chromobacteriaceae, "Chitinibacteraceae", "Aquaspirillaceae" and "Leeiaceae" clades, respectively. Based on the strong phylogenetic and molecular evidence presented here, we are proposing that the three newly identified clades should be recognized as novel families (Chitinibacteraceae fam. nov., Aquaspirillaceae fam. nov. and Leeiaceae fam. nov.) within the order Neisseriales. In addition, we are also emending descriptions of the families Neisseriaceae and Chromobacteriaceae regarding their constituent genera and other distinguishing characteristics.

Eikenella glucosivorans sp. nov., isolated from a human throat swab, and emendation of the genus Eikenella to include saccharolytic species

A novel species within the genus Eikenella is described, based on the phenotypical, biochemical and genetic characterization of a strain of a facultatively anaerobic, Gram-negative rod-shaped bacterium. Strain S3360^T was isolated from the throat swab of a patient sampled during routine care at a hospital. Phylogenetic analyses (full-length 16S rRNA gene and whole-genome sequences) placed the strain in the genus Eikenella, separate from all recognized species but with the closest relationship to Eikenella longinqua (NML 02-A-017^T). Eikenella is one of the genera in the HACEK group known to be responsible for rare cases of endocarditis in humans. Until the recent descriptions of Eikenella exigua, Eikenella halliae and Eikenella longinqua, Eikenella corrodens had been the only validly published species in this genus since its description as Bacteroides corrodens in 1958. Unlike these species, strain S3360^T is able to metabolize carbohydrates (glucose). The average nucleotide identities of strain S3360^T with E. longinqua (NML 02-A-017^T) and E. corrodens (NCTC 10596^T), the type species of the genus, were 90.5 and 84.7 %, respectively, and the corresponding genome-to-genome distance values were 41.3 and 29.0 %, respectively. The DNA G+C content of strain S3360^T was 58.4 mol%. Based on the phenotypical, biochemical and genetic findings, strain S3360^T is considered to represent a novel species within the genus Eikenella, for which the name Eikenella glucosivorans sp. nov. is proposed. The type strain is S3360^T (DSM 110714^T=CCOS 1935^T=CCUG 74293^T). In addition, an emendation of the genus Eikenella is proposed to include species which are saccharolytic.

Vitreoscilla massiliensis sp. nov., Isolated From the Stool of an Amazonian Patient

Strain SN6^T is a non-motile and non-spore-forming gram-negative bacterium which was isolated from the stool sample of an Amazonian patient. The optimum growth was observed at 37 °C, pH 7, and 0–5 g/l of NaCl. Based on the 16S rRNA gene sequence similarity, the strain SN6^T exhibited 97.5% identity with Vitreoscilla stercoraria strain ATCC_15218 (L06174), the phylogenetically closest species with standing in nomenclature. The predominant fatty acid was hexadecenoic acid (31%). The genomic DNA G + C content of the strain SN6^T was 49.4 mol %. After analysis of taxonogenomic data, phenotypic and biochemical characteristics, we concluded that strain SN6^T represents a new species of the genus Vitreoscilla for which the name Vitreoscilla massiliensis sp.nov is proposed. The type strain is SN6^T (=CSUR P2036 = LN870312 = DSM 100958).

Draft Genome Sequence of Vogesella oryzae L3B39T, Isolated from the Rhizosphere of Saline-Tolerant Pokkali Rice

Here, we report the draft genome sequence of Vogesella oryzae L3B39^T (CSUR Q2602^T = DSM 28780), which is a Vogesella species isolated from the rhizosphere of saline-tolerant pokkali rice. The genome sequence was assembled into 58 contigs for a total size of 3,415,129 bp, with a G+C content of 62.3%.

Here, we report the draft genome sequence of Vogesella oryzae L3B39^T (CSUR Q2602^T = DSM 28780), which is a Vogesella species isolated from the rhizosphere of saline-tolerant pokkali rice. The genome sequence was assembled into 58 contigs for a total size of 3,415,129 bp, with a G+C content of 62.3%.

Osteoarticular Infection in Three Young Thoroughbred Horses Caused by a Novel Gram Negative Cocco-Bacillus

We describe three cases of osteoarticular infection (OAI) in young thoroughbred horses in which the causative organism was identified by MALDI-TOF as Kingella species. The pattern of OAI resembled that reported with Kingella infection in humans. Analysis by 16S rRNA PCR enabled construction of a phylogenetic tree that placed the isolates closer to Simonsiella and Alysiella species, rather than Kingella species. Average nucleotide identity (ANI) comparison between the new isolate and Kingella kingae and Alysiella crassa however revealed low probability that the new isolate belonged to either of these species. This preliminary analysis suggests the organism isolated is a previously unrecognised species.

Gonorrhoea

The bacterium Neisseria gonorrhoeae causes the sexually transmitted infection (STI) gonorrhoea, which has an estimated global annual incidence of 86.9 million adults. Gonorrhoea can present as urethritis in men, cervicitis or urethritis in women, and in extragenital sites (pharynx, rectum, conjunctiva and, rarely, systemically) in both sexes. Confirmation of diagnosis requires microscopy of Gram-stained samples, bacterial culture or nucleic acid amplification tests. As no gonococcal vaccine is available, prevention relies on promoting safe sexual behaviours and reducing STI-associated stigma, which hinders timely diagnosis and treatment thereby increasing transmission. Single-dose systemic therapy (usually injectable ceftriaxone plus oral azithromycin) is the recommended first-line treatment. However, a major public health concern globally is that N. gonorrhoeae is evolving high levels of antimicrobial resistance (AMR), which threatens the effectiveness of the available gonorrhoea treatments. Improved global surveillance of the emergence, evolution, fitness, and geographical and temporal spread of AMR in N. gonorrhoeae, and improved understanding of the pharmacokinetics and pharmacodynamics for current and future antimicrobials in the treatment of urogenital and extragenital gonorrhoea, are essential to inform treatment guidelines. Key priorities for gonorrhoea control include strengthening prevention, early diagnosis, and treatment of patients and their partners; decreasing stigma; expanding surveillance of AMR and treatment failures; and promoting responsible antimicrobial use and stewardship. To achieve these goals, the development of rapid and affordable point-of-care diagnostic tests that can simultaneously detect AMR, novel therapeutic antimicrobials and gonococcal vaccine(s) in particular is crucial.

Neisseria chenwenguii sp. nov. isolated from the rectal contents of a plateau pika (Ochotona curzoniae)

Two Gram-stain negative, catalase positive, coccus shaped bacteria, designated 10023^T and 10010, were isolated from the rectal contents of a plateau pika (Ochotona curzoniae) in Qinghai–Tibet Plateau, China. Based on 16S rRNA gene sequence analysis, phylogenetic trees showed that these two isolates (10023^T, 10010) group with members of the genus Neisseria. Additionally, these two isolates exhibited high 16S rRNA gene sequence similarity with Neisseria zalophi CSL 7565^T (96.98%), Neisseria wadsworthii WC 05-9715^T (96.92%) and Neisseria canis ATCC 14687^T (96.79%). Further phylogenetic analysis based on the rplF gene showed that these two novel strains can be easily discriminated from phylogenetically closely related species. Optimal growth was found to occur on BHI agar with 5% defibrinated sheep blood at 37 °C and growth was also observed on nutrient agar, Columbia blood agar and chocolate agar plates; however, growth was not observed on MacConkey agar after 7 days. The major cellular fatty acids of these strains were identified as C_16:0 and C_16:1ω7c/C_16:1ω6c. The complete genome size of the type strain 10023^T is 2,496,444 bp, with DNA G+C content of 54.0 mol %. The average nucleotide identity values were 73.5–79.3% between isolate 10023^T and reference Neisseria spp. Based on polyphasic analysis, these isolates (10023^T and 10010) are considered to represent a novel species in the genus Neisseria, for which the name Neisseria chenwenguii sp. nov. is proposed. The type strain is 10023^T (= DSM 103440^T = CGMCC 1.15736^T).

Aquella oligotrophica gen. nov. sp. nov.: A new member of the family Neisseriaceae isolated from laboratory tap water

A bacterial strain designated as P08^T was isolated from laboratory tap water during a water quality assessment in University of Malaya, Malaysia. The strain was a Gram-negative, rod-shaped, nonmotile, and aerobic bacterium. Complete genome of P08^T comprised of a 2,820,660 bp chromosome with a G + C content of 36.43%. Both 16S rRNA phylogeny and phylogenetic tree inferred from the core gene matrix demonstrated that P08^T formed a hitherto unknown subline within the family Neisseriaceae. Ortho average nucleotide identity (OrthoANI) values and the percentage of conserved proteins (POCP) calculated from complete genome sequence indicated low relatedness between P08^T and its phylogenetic neighbors. Respiratory quinone analysis revealed Q-8 as the only detectable quinone. The predominant cellular fatty acids were identified as C_14:0 , iso-C_15:0 , and summed feature 3 (C_16:1 ω7c/C_16:1 ω6c). The polar lipids consisted of uncharacterized aminolipid, phosphatidylglycerol, and phosphatidylethanolamine. All aspects of phenotypic and phylogenetic data suggested that strain P08^T represents a novel genus within family Neisseriaceae, for which the name Aquella gen. nov. is proposed. The type species of the genus is Aquella oligotrophica sp. nov., and the type strain is P08^T (=LMG 29629^T =DSM 100970^T ).

Insights into the Genome Sequence of Chromobacterium amazonense Isolated from a Tropical Freshwater Lake

Members of the genus Chromobacterium have been isolated from geographically diverse ecosystems and exhibit considerable metabolic flexibility, as well as biotechnological and pathogenic properties in some species. This study reports the draft assembly and detailed sequence analysis of Chromobacterium amazonense strain 56AF. The de novo-assembled genome is 4,556,707 bp in size and contains 4294 protein-coding and 95 RNA genes, including 88 tRNA, six rRNA, and one tmRNA operon. A repertoire of genes implicated in virulence, for example, hemolysin, hemolytic enterotoxins, colicin V, lytic proteins, and Nudix hydrolases, is present. The genome also contains a collection of genes of biotechnological interest, including esterases, lipase, auxins, chitinases, phytoene synthase and phytoene desaturase, polyhydroxyalkanoates, violacein, plastocyanin/azurin, and detoxifying compounds. Importantly, unlike other Chromobacterium species, the 56AF genome contains genes for pore-forming toxin alpha-hemolysin, a type IV secretion system, among others. The analysis of the C. amazonense strain 56AF genome reveals the versatility, adaptability, and biotechnological potential of this bacterium. This study provides molecular information that may pave the way for further comparative genomics and functional studies involving Chromobacterium-related isolates and improves our understanding of the global genomic diversity of Chromobacterium species.

Neisseria arctica sp. nov., isolated from nonviable eggs of greater white-fronted geese (Anser albifrons) in Arctic Alaska

During the summers of 2013 and 2014, isolates of a novel Gram-stain-negative coccus in the genus Neisseriawere obtained from the contents of nonviable greater white-fronted goose (Anseralbifrons) eggs on the Arctic Coastal Plain of Alaska. We used a polyphasic approach to determine whether these isolates represent a novel species. 16S rRNA gene sequences, 23S rRNA gene sequences, and chaperonin 60 gene sequences suggested that these Alaskan isolates are members of a distinct species that is most closely related to Neisseria canis, Neisseriaanimaloris and Neisseriashayeganii. Analysis of the rplF gene additionally showed that the isolates are unique and most closely related to Neisseriaweaveri. Average nucleotide identity of the whole genome sequence of the type strain was between 71.5 and 74.6 % compared to close relatives, further supporting designation as a novel species. Fatty acid methyl ester analysis showed a predominance of C14 : 0, C16 : 0 and C16 : 1ω7c fatty acids. Finally, biochemical characteristics distinguished the isolates from other species of the genus Neisseria. On the basis of these combined data, the isolates are proposed to represent a novel species of the genus Neisseria, with the name Neisseria arctica sp. nov. The type strain is KH1503T (=ATCC TSD-57T=DSM 103136T).

Denitrification and Nitrate-Dependent Fe(II) Oxidation in Various Pseudogulbenkiania Strains

Pseudogulbenkiania is a relatively recently characterized genus within the order Neisseriales, class Betaproteobacteria. This genus contains several strains that are capable of anaerobic, nitrate-dependent Fe(II) oxidation (NDFO), a geochemically important reaction for nitrogen and iron cycles. In the present study, we examined denitrification functional gene diversities within this genus, and clarified whether other Pseudogulbenkiania sp. strains perform denitrification and NDFO. Seventy strains were analyzed, including two type strains, a well-characterized NDFO strain, and 67 denitrifying strains isolated from various rice paddy fields and rice-soybean rotation fields in Japan. We also attempted to identify the genes responsible for NDFO by mutagenesis. Our comprehensive analysis showed that all Pseudogulbenkiania strains tested performed denitrification and NDFO; however, we were unable to obtain NDFO-deficient denitrifying mutants in our mutagenesis experiment. This result suggests that Fe(II) oxidation in these strains is not enzymatic, but is caused by reactive N-species that are formed during nitrate reduction. Based on the results of the comparative genome analysis among Pseudogulbenkiania sp. strains, we identified low sequence similarity within the nos gene as well as different gene arrangements within the nos gene cluster, suggesting that nos genes were horizontally transferred. Since Pseudogulbenkiania sp. strains have been isolated from various locations around the world, their denitrification and NDFO abilities may contribute significantly to nitrogen and iron biogeochemical cycles.

Impact of genomics on the understanding of microbial evolution and classification: the importance of Darwin's views on classification

Analyses of genome sequences, by some approaches, suggest that the widespread occurrence of horizontal gene transfers (HGTs) in prokaryotes disguises their evolutionary relationships and have led to questioning of the Darwinian model of evolution for prokaryotes. These inferences are critically examined in the light of comparative genome analysis, characteristic synapomorphies, phylogenetic trees and Darwin's views on examining evolutionary relationships. Genome sequences are enabling discovery of numerous molecular markers (synapomorphies) such as conserved signature indels (CSIs) and conserved signature proteins (CSPs), which are distinctive characteristics of different prokaryotic taxa. Based on these molecular markers, exhibiting high degree of specificity and predictive ability, numerous prokaryotic taxa of different ranks, currently identified based on the 16S rRNA gene trees, can now be reliably demarcated in molecular terms. Within all studied groups, multiple CSIs and CSPs have been identified for successive nested clades providing reliable information regarding their hierarchical relationships and these inferences are not affected by HGTs. These results strongly support Darwin's views on evolution and classification and supplement the current phylogenetic framework based on 16S rRNA in important respects. The identified molecular markers provide important means for developing novel diagnostics, therapeutics and for functional studies providing important insights regarding prokaryotic taxa.

Microbial Infections Are Associated with Embryo Mortality in Arctic-Nesting Geese

To address the role of bacterial infection in hatching failure of wild geese, we monitored embryo development in a breeding population of Greater white-fronted geese (Anser albifrons) on the Arctic Coastal Plain of Alaska. During 2013, we observed mortality of normally developing embryos and collected 36 addled eggs for analysis. We also collected 17 infertile eggs for comparison. Using standard culture methods and gene sequencing to identify bacteria within collected eggs, we identified a potentially novel species of Neisseria in 33 eggs, Macrococcus caseolyticus in 6 eggs, and Streptococcus uberis and Rothia nasimurium in 4 eggs each. We detected seven other bacterial species at lower frequencies. Sequences of the 16S rRNA genes from the Neisseria isolates most closely matched sequences from N. animaloris and N. canis (96 to 97% identity), but phylogenetic analysis suggested substantial genetic differentiation between egg isolates and known Neisseria species. Although definitive sources of the bacteria remain unknown, we detected Neisseria DNA from swabs of eggshells, nest contents, and cloacae of nesting females. To assess the pathogenicity of bacteria identified in contents of addled eggs, we inoculated isolates of Neisseria, Macrococcus, Streptococcus, and Rothia at various concentrations into developing chicken eggs. Seven-day mortality rates varied from 70 to 100%, depending on the bacterial species and inoculation dose. Our results suggest that bacterial infections are a source of embryo mortality in wild geese in the Arctic.

Draft Genome Sequence of a Taxonomically Unique Neisseria Strain Isolated from a Greater White-Fronted Goose (Anser albifrons) Egg on the North Slope of Alaska

We report here the draft genome sequence of a unique Neisseria strain that was isolated from a greater white-fronted goose (Anser albifrons) egg. The sequencing was performed with an Illumina MiSeq system, and the sequence consists of 275 contigs. The total genome is 2,397,978 bp long and has a G+C content of 46.4%.

Common Cell Shape Evolution of Two Nasopharyngeal Pathogens

Respiratory infectious diseases are the third cause of worldwide death. The nasopharynx is the portal of entry and the ecological niche of many microorganisms, of which some are pathogenic to humans, such as Neisseria meningitidis and Moraxella catarrhalis. These microbes possess several surface structures that interact with the actors of the innate immune system. In our attempt to understand the past evolution of these bacteria and their adaption to the nasopharynx, we first studied differences in cell wall structure, one of the strongest immune-modulators. We were able to show that a modification of peptidoglycan (PG) composition (increased proportion of pentapeptides) and a cell shape change from rod to cocci had been selected for along the past evolution of N. meningitidis. Using genomic comparison across species, we correlated the emergence of the new cell shape (cocci) with the deletion, from the genome of N. meningitidis ancestor, of only one gene: yacF. Moreover, the reconstruction of this genetic deletion in a bacterium harboring the ancestral version of the locus together with the analysis of the PG structure, suggest that this gene is coordinating the transition from cell elongation to cell division. Accompanying the loss of yacF, the elongation machinery was also lost by several of the descendants leading to the change in the PG structure observed in N. meningitidis. Finally, the same evolution was observed for the ancestor of M. catarrhalis. This suggests a strong selection of these genetic events during the colonization of the nasopharynx. This selection may have been forced by the requirement of evolving permissive interaction with the immune system, the need to reduce the cellular surface exposed to immune attacks without reducing the intracellular storage capacity, or the necessity to better compete for adhesion to target cells.

The nasopharynx hosts an important microbial community that comprises some well-known pathogens such as Neisseria meningitidis and Moraxella catarrhalis. In some circumstances, it also represents the portal of entry of systemic infections such as septicemia and meningitis, or infections of the respiratory system, middle ear, eye, central nervous system and joints of humans, caused by N. meningitidis and M. catarrhalis, respectively. In this article, we demonstrated that both bacteria underwent a similar cell shape evolution that resulted in a transition from a bacillus to a coccus. This was consequently accompanied by a change, similar for both bacteria, in the structure of the PG, the major bacterial cell shape determinant and also a strongly recognized molecule by the immune system. In our efforts in understanding the evolutionary events that led to the cell shape transition in N. meningitidis, we identified two genetic deletion events required for the shape transition, i.e. of yacF (zapD) and the cell elongation machinery. Furthermore, we delineated the importance of YacF (ZapD) in the coordination of the cell elongation and division. Finally, we suggest that this transition was selected to reduce the cell surface sensible to immune attacks and to redistribute surface appendages, such as pili, to acquire new properties of cell adhesion or movement necessary for the proper colonization of the nasopharynx.

Molecular characterization of arginine deiminase pathway in Laribacter hongkongensis and unique regulation of arginine catabolism and anabolism by multiple environmental stresses

The betaproteobacterium Laribacter hongkongensis is associated with invasive bacteremic infections and gastroenteritis. Its genome contains two adjacent arc gene cassettes (arc1 and arc2) under independent transcriptional control, which are essential for acid resistance. Laribacter hongkongensis also encodes duplicate copies of the argA and argB genes from the arginine biosynthesis pathway. We show that arginine enhances the transcription of arcA2 but suppresses arcA1 expression. We demonstrate that ArgR acts as a transcriptional regulator of the two arc operons through binding to ARG operator sites (ARG boxes). Upon temperature shift from 20°C to 37°C, arcA1 transcription is upregulated while arcA2, argA2, argB2 and argG are downregulated. The transcription of arcA1 and arcA2 are augmented under anaerobic and acidic conditions. The transcription levels of argA1, argA2, argB1, argB2 and argG are significantly increased under anaerobic and acidic conditions but are repressed by the addition of arginine. Deletion of argR significantly decreases bacterial survival in macrophages, while expression of both arc operons, argR and all five of the anabolic arg genes increases 8 h post-infection. Our results show that arginine catabolism in L. hongkongensis is finely regulated by controlling the transcription of two arc operons, whereas arginine anabolism is controlled by two copies of argA and argB.

Marinobacter shengliensis sp. nov., a moderately halophilic bacterium isolated from oil-contaminated saline soil

Two moderately halophilic strains, designated SL013A34A2(T) and SL013A24A, were isolated from oil-contaminated saline soil from Shengli Oilfield, eastern China. Cells were found to be Gram-staining negative, aerobic, rod-shaped with a single polar flagellum. The isolates were found to grow at 10-40 °C (optimum 35 °C), pH 6.0-9.0 (optimum pH 8.0), and NaCl concentrations of 0.5-18.0 % (w/v) (optimum 3.0-6.0 NaCl). The 16S rRNA gene sequence analysis indicated that the isolates belong to the genus Marinobacter. Strain SL013A34A2(T) shares the highest 16S rRNA gene sequence similarities with strain SL013A24A (99.3 %), followed by M. hydrocarbonoclasticus CGMCC 1.7683(T) (97.8 %), M. vinifirmus CGMCC 1.7265(T) (97.8 %), and M. excellens KMM 3809(T) (97.4 %), respectively, but low similarities (93.8-96.4 %) with type strains of the other numbers of genus Marinobacter. DNA-DNA relatedness values of strain SL013A34A2(T) with strains SL013A24A, M. hydrocarbonoclasticus CGMCC 1.7683(T), M. vinifirmus CGMCC 1.7265(T) and M. excellens KMM 3809(T) were 88.7, 29.2, 33.4 and 29.4 %, respectively. The major fatty acids of strain SL013A34A2(T) were identified as C18:1 ω9c, C16:0, C12:03-OH, C12:0, C16:1 ω9c and 10-methyl C18:0. The major respiratory quinone of strain SL013A34A2(T) was found to be ubiquinone-9, and its predominant polar lipids were identified as diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and unidentified glycolipid. The genomic DNA G + C content was found to be 56.1 mol %. Based on the phenotypic, genetic and chemotaxonomic characteristics, these two isolates are representatives of a novel species of the genus Marinobacter, for which the name Marinobacter shengliensis sp. nov. is proposed. The type strain is SL013A34A2(T)(=LMG 27740(T) = CGMCC 1.12758(T)).

Uruburuella testudinis sp. nov., isolated from tortoise (Testudo)

A polyphasic taxonomic analysis was carried out on 11 uncommon Gram-stain-negative, non-motile, catalase- and oxidase-positive, but indole-negative, bacterial strains isolated from tortoises. Phenotypically and genetically they represented a homogeneous group of organisms most closely related to, but distinct from, Uruburuella suis. In a reconstructed 16S rRNA gene tree they clustered on a monophyletic branch next to U. suis with gene similarities between strains of 99.5-100%, and of up to 98.2% with U. suis . DNA-DNA hybridization indicated the organisms represented a novel species with only 40% DNA-DNA similarity with U. suis . Partial sequencing of rpoB resulted in two subclusters confirming the 16S rRNA gene phylogeny; both genes allowed clear separation and identification of the novel species. Furthermore, they could be unambiguously identified by matrix-assisted laser desorption ionization time-of-flight MS, where, again, they formed a highly homogeneous cluster separate from U. suis and other members of the family Neisseriaceae . The major fatty acids were C(16 : 0) and summed feature C(16 : 1)ω7c/iso-C(15 : 0) 2-OH. The DNA G+C content was 54.4 mol%. Based on phenotypic and genetic data we propose classifying these organisms as representatives of a novel species named Uruburuella testudinis sp. nov. The type strain is 07_OD624(T) ( = DSM 26510(T) = CCUG 63373(T)).

Kingella kingae: carriage, transmission, and disease

Kingella kingae is a common etiology of pediatric bacteremia and the leading agent of osteomyelitis and septic arthritis in children aged 6 to 36 months. This Gram-negative bacterium is carried asymptomatically in the oropharynx and disseminates by close interpersonal contact. The colonized epithelium is the source of bloodstream invasion and dissemination to distant sites, and certain clones show significant association with bacteremia, osteoarthritis, or endocarditis. Kingella kingae produces an RTX (repeat-in-toxin) toxin with broad-spectrum cytotoxicity that probably facilitates mucosal colonization and persistence of the organism in the bloodstream and deep body tissues. With the exception of patients with endocardial involvement, children with K. kingae diseases often show only mild symptoms and signs, necessitating clinical acumen. The isolation of K. kingae on routine solid media is suboptimal, and detection of the bacterium is significantly improved by inoculating exudates into blood culture bottles and the use of PCR-based assays. The organism is generally susceptible to antibiotics that are administered to young patients with joint and bone infections. β-Lactamase production is clonal, and the local prevalence of β-lactamase-producing strains is variable. If adequately and promptly treated, invasive K. kingae infections with no endocardial involvement usually run a benign clinical course.

Phylogenetic analysis and molecular signatures defining a monophyletic clade of heterocystous cyanobacteria and identifying its closest relatives

Detailed phylogenetic and comparative genomic analyses are reported on 140 genome sequenced cyanobacteria with the main focus on the heterocyst-differentiating cyanobacteria. In a phylogenetic tree for cyanobacteria based upon concatenated sequences for 32 conserved proteins, the available cyanobacteria formed 8-9 strongly supported clades at the highest level, which may correspond to the higher taxonomic clades of this phylum. One of these clades contained all heterocystous cyanobacteria; within this clade, the members exhibiting either true (Nostocales) or false (Stigonematales) branching of filaments were intermixed indicating that the division of the heterocysts-forming cyanobacteria into these two groups is not supported by phylogenetic considerations. However, in both the protein tree as well as in the 16S rRNA gene tree, the akinete-forming heterocystous cyanobacteria formed a distinct clade. Within this clade, the members which differentiate into hormogonia or those which lack this ability were also separated into distinct groups. A novel molecular signature identified in this work that is uniquely shared by the akinete-forming heterocystous cyanobacteria provides further evidence that the members of this group are specifically related and they shared a common ancestor exclusive of the other cyanobacteria. Detailed comparative analyses on protein sequences from the genomes of heterocystous cyanobacteria reported here have also identified eight conserved signature indels (CSIs) in proteins involved in a broad range of functions, and three conserved signature proteins, that are either uniquely or mainly found in all heterocysts-forming cyanobacteria, but generally not found in other cyanobacteria. These molecular markers provide novel means for the identification of heterocystous cyanobacteria, and they provide evidence of their monophyletic origin. Additionally, this work has also identified seven CSIs in other proteins which in addition to the heterocystous cyanobacteria are uniquely shared by two smaller clades of cyanobacteria, which form the successive outgroups of the clade comprising of the heterocystous cyanobacteria in the protein trees. Based upon their close relationship to the heterocystous cyanobacteria, the members of these clades are indicated to be the closest relatives of the heterocysts-forming cyanobacteria.

Phylogeny and molecular signatures for the phylum Fusobacteria and its distinct subclades

The members of the phylum Fusobacteria and its two families, Fusobacteriaceae and Leptotrichiaceae, are distinguished at present mainly on the basis of their branching in the 16S rRNA gene trees and analysis of the internal transcribed spacer sequences in the 16S-23S rDNA. However, no biochemical or molecular characteristics are known that are uniquely shared by all of most members of these groups of bacteria. We report here detailed phylogenetic and comparative analyses on 45 sequenced Fusobacteria genomes to examine their evolutionary relationships and to identify molecular markers that are specific for the members of this phylum. In phylogenetic trees based on 16S rRNA gene sequences or concatenated sequences for 17 conserved proteins, members of the families Fusobacteriaceae and Leptotrichiaceae formed strongly supported clades and were clearly distinguished. In these trees, the species from the genus Fusobacterium also formed a number of well-supported clades. In parallel, comparative analyses on Fusobacteria genomes have identified 44 conserved signature indels (CSIs) in proteins involved in a broad range of functions that are either specific for the phylum Fusobacteria or a number of distinct subclades within this phylum. Seven of these CSIs in important proteins are uniquely present in the protein homologs of all sequenced Fusobacteria and they provide potential molecular markers for this phylum. Six and three other CSIs in other protein sequences are specific for members of the families Fusobacteriaceae and Leptotrichiaceae, respectively, and they provide novel molecular means for distinguishing members of these two families. Fourteen additional CSIs in different proteins, which are specific for either members of the genera Fusobacterium or Leptotrichia, or a number of other well-supported clades of Fusobacteria at multiple phylogenetic levels, provide molecular markers for these groups and information regarding the evolutionary relationships among the members of this phylum. Lastly, the present work has also identified 14 CSIs in divergent proteins that are specific for three specific subclades of Fusobacterium species, which are also indicated to be distinct by phylogenetic analyses. The members of these three Fusobacterium subclades also differ significantly from each other in their whole genome average nucleotide identities values, suggesting that they are possible candidates for recognition as different genera. The molecular markers reported here provide novel means for the identification of members of the phylum Fusobacteria and for their classification.

A phylogenomic and molecular marker based proposal for the division of the genus Borrelia into two genera: the emended genus Borrelia containing only the members of the relapsing fever Borrelia, and the genus Borreliella gen. nov. containing the members of the Lyme disease Borrelia (Borrelia burgdorferi sensu lato complex)

The genus Borrelia contains two groups of organisms: the causative agents of Lyme disease and their relatives and the causative agents of relapsing fever and their relatives. These two groups are morphologically indistinguishable and are difficult to distinguish biochemically. In this work, we have carried out detailed comparative genomic analyses on protein sequences from 38 Borrelia genomes to identify molecular markers in the forms of conserved signature inserts/deletions (CSIs) that are specifically found in the Borrelia homologues, and conserved signature proteins (CSPs) which are uniquely present in Borrelia species. Our analyses have identified 31 CSIs and 82 CSPs that are uniquely shared by all sequenced Borrelia species, providing molecular markers for this group of organisms. In addition, our work has identified 7 CSIs and 21 CSPs which are uniquely found in the Lyme disease Borrelia species and eight CSIs and four CSPs that are specific for members of the relapsing fever Borrelia group. Additionally, 38 other CSIs, in proteins which are uniquely found in Borrelia species, also distinguish these two groups of Borrelia. The identified CSIs and CSPs provide novel and highly specific molecular markers for identification and distinguishing between the Lyme disease Borrelia and the relapsing fever Borrelia species. We also report the results of average nucleotide identity (ANI) analysis on Borrelia genomes and phylogenetic analysis for these species based upon 16S rRNA sequences and concatenated sequences for 25 conserved proteins. These analyses also support the distinctness of the two Borrelia clades. On the basis of the identified molecular markers, the results from ANI and phylogenetic studies, and the distinct pathogenicity profiles and arthropod vectors used by different Borrelia spp. for their transmission, we are proposing a division of the genus Borrelia into two separate genera: an emended genus Borrelia, containing the causative agents of relapsing fever and a novel genus, Borreliella gen. nov., containing the causative agents of Lyme disease.

Notification of changes in taxonomic opinion previously published outside the IJSEM

The Bacteriological Code deals with the nomenclature of prokaryotes. This may include existing names (the Approved Lists of Bacterial Names) as well as new names and new combinations. In this sense the Code is also dealing indirectly with taxonomic opinions. However, as with most codes of nomenclature there are no mechanisms for formally recording taxonomic opinions that do not involve the creation of new names or new combinations. In particular, it would be desirable for taxonomic opinions resulting from the creation of synonyms or emended descriptions to be made widely available to the public. In 2004, the Editorial Board of the International Journal of Systematic and Evolutionary Microbiology (IJSEM) agreed unanimously that it was desirable to cover such changes in taxonomic opinions (i.e. the creation of synonyms or the emendation of circumscriptions) previously published outside the IJSEM, and to introduce a List of Changes in Taxonomic Opinion [Notification of changes in taxonomic opinion previously published outside the IJSEM; Euzéby et al. (2004). Int J Syst Evol Microbiol 54, 1429–1430]. Scientists wishing to have changes in taxonomic opinion included in future lists should send one copy of the pertinent reprint or a photocopy or a PDF file thereof to the IJSEM Editorial Office or to the Lists Editor. It must be stressed that the date of proposed taxonomic changes is the date of the original publication not the date of publication of the list. Taxonomic opinions included in the List of Changes in Taxonomic Opinion cannot be considered as validly published nor, in any other way, approved by the International Committee on Systematics of Prokaryotes and its Judicial Commission. The names that are to be used are those that are the ‘correct names’ (in the sense of Principle 6) in the opinion of the bacteriologist, with a given circumscription, position and rank. A particular name, circumscription, position and rank do not have to be adopted in all circumstances. Consequently, the List of Changes in Taxonomic Opinion must be considered as a service to bacteriology and it has no ‘official character’, other than providing a centralized point for registering/indexing such changes in a way that makes them easily accessible to the scientific communit y.

List of new names and new combinations previously effectively, but not validly, published

The purpose of this announcement is to effect the valid publication of the following effectively published new names and new combinations under the procedure described in the Bacteriological Code (1990 Revision). Authors and other individuals wishing to have new names and/or combinations included in future lists should send three copies of the pertinent reprint or photocopies thereof, or an electronic copy of the published paper to the IJSEM Editorial Office for confirmation that all of the other requirements for valid publication have been met. It is also a requirement of IJSEM and the ICSP that authors of new species, new subspecies and new combinations provide evidence that types are deposited in two recognized culture collections in two different countries. It should be noted that the date of valid publication of these new names and combinations is the date of publication of this list, not the date of the original publication of the names and combinations. The authors of the new names and combinations are as given below. Inclusion of a name on these lists validates the publication of the name and thereby makes it available in the nomenclature of prokaryotes. The inclusion of a name on this list is not to be construed as taxonomic acceptance of the taxon to which the name is applied. Indeed, some of these names may, in time, be shown to be synonyms, or the organisms may be transferred to another genus, thus necessitating the creation of a new combination.

A phylogenomic and molecular signature based approach for characterization of the phylum Spirochaetes and its major clades: proposal for a taxonomic revision of the phylum

The Spirochaetes species cause many important diseases including syphilis and Lyme disease. Except for their containing a distinctive endoflagella, no other molecular or biochemical characteristics are presently known that are specific for either all Spirochaetes or its different families. We report detailed comparative and phylogenomic analyses of protein sequences from Spirochaetes genomes to understand their evolutionary relationships and to identify molecular signatures for this group. These studies have identified 38 conserved signature indels (CSIs) that are specific for either all members of the phylum Spirochaetes or its different main clades. Of these CSIs, a 3 aa insert in the FlgC protein is uniquely shared by all sequenced Spirochaetes providing a molecular marker for this phylum. Seven, six, and five CSIs in different proteins are specific for members of the families Spirochaetaceae, Brachyspiraceae, and Leptospiraceae, respectively. Of the 19 other identified CSIs, 3 are uniquely shared by members of the genera Sphaerochaeta, Spirochaeta, and Treponema, whereas 16 others are specific for the genus Borrelia. A monophyletic grouping of the genera Sphaerochaeta, Spirochaeta, and Treponema distinct from the genus Borrelia is also strongly supported by phylogenetic trees based upon concatenated sequences of 22 conserved proteins. The molecular markers described here provide novel and more definitive means for identification and demarcation of different main groups of Spirochaetes. To accommodate the extensive genetic diversity of the Spirochaetes as revealed by different CSIs and phylogenetic analyses, it is proposed that the four families of this phylum should be elevated to the order level taxonomic ranks (viz. Spirochaetales, Brevinematales ord. nov., Brachyspiriales ord. nov., and Leptospiriales ord. nov.). It is further proposed that the genera Borrelia and Cristispira be transferred to a new family Borreliaceae fam. nov. within the order Spirochaetales.