Air-directed attachment of coccoid bacteria to the surface of superhydrophobic lotus-like titanium

Superhydrophobic titanium surfaces fabricated by femtosecond laser ablation to mimic the structure of lotus leaves were assessed for their ability to retain coccoid bacteria. Staphylococcus aureus CIP 65.8T, S. aureus ATCC 25923, S. epidermidis ATCC 14990T and Planococcus maritimus KMM 3738 were retained by the surface, to varying degrees. However, each strain was found to preferentially attach to the crevices located between the microscale surface features. The upper regions of the microscale features remained essentially cell-free. It was hypothesised that air entrapped by the topographical features inhibited contact between the cells and the titanium substratum. Synchrotron SAXS revealed that even after immersion for 50 min, nano-sized air bubbles covered 45% of the titanium surface. After 1 h the number of cells of S. aureus CIP 65.8T attached to the lotus-like titanium increased to 1.27×10(5) mm(-2), coinciding with the replacement of trapped air by the incubation medium.     

Prescottia equi gen. nov., comb. nov.: a new home for an old pathogen

The taxonomic status of Rhodococcus equi, originally isolated from foal specimens, has been the subject of discussion for a number of years. The chequered history of the taxon has prompted this polyphasic analysis of R. equi strains, close members of the genus Rhodococcus and representatives of other genera classified in the order Corynebacteriales, to establish the taxonomic position of this taxon. Thirty one R. equi strains, including the type strain, were examined for genotypic and numerical taxonomic properties. The resultant data are consistent with their classification in the order Corynebacteriales but the R. equi strains formed a distinct phyletic clade away from representatives of other members of the genus Rhodococcus in the 16S rRNA gene tree. Representatives of this clade shared their highest pairwise 16S rRNA gene sequence similarities with the type strain of Rhodococcus kunmingensis (95.2–98.1 %). However, the R. equi taxon was readily distinguished from R. kunmingensis and from the other members of the order Corynebacteriales using a combination of genotypic, chemotypic and phenotypic properties. On the basis of these data the R. equi strains are considered to represent a new genus. The name proposed for this taxon is Prescottia gen. nov., with Prescottia equi comb. nov. as the type species containing the type strain, C 7^T (= ATCC 25729^T = ATCC 6939^T = CCUG 892^T = CIP 54.72^T = DSM 20307^T = HAMBI 2061^T = NBRC 14956^T = JCM 1311^T = JCM 3209^T = LMG 18452^T = NBRC 101255^T = NCTC 1621^T = NRRL B-16538^T = VKM Ac-953^T).     

Streptomyces-derived actinomycin D inhibits biofilm formation by Staphylococcus aureus and its hemolytic activity

Staphylococcus aureus is a versatile human pathogen that produces diverse virulence factors, and its biofilm cells are difficult to eradicate due to their inherent ability to tolerate antibiotics. The anti-biofilm activities of the spent media of 252 diverse endophytic microorganisms were investigated using three S. aureus strains. An attempt was made to identify anti-biofilm compounds in active spent media and to assess their anti-hemolytic activities and hydrophobicities in order to investigate action mechanisms. Unlike other antibiotics, actinomycin D (0.5 μg ml^?1) from Streptomyces parvulus significantly inhibited biofilm formation by all three S. aureus strains. Actinomycin D inhibited slime production in S. aureus and it inhibited hemolysis by S. aureus and caused S. aureus cells to become less hydrophobic, thus supporting its anti-biofilm effect. In addition, surface coatings containing actinomycin D prevented S. aureus biofilm formation on glass surfaces. Given these results, FDA-approved actinomycin D warrants further attention as a potential antivirulence agent against S. aureus infections.     

Effect of ultrafine-grained titanium surfaces on adhesion of bacteria

The influence of the ultrafine crystallinity of commercial purity grade 2 (as-received) titanium and titanium modified by equal channel angular pressing (modified titanium) on bacterial attachment was studied. A topographic profile analysis of the surface of the modified titanium revealed a complex morphology of the surface. Its prominent micro- and nano-scale features were 100–200-nm-scale undulations with 10–15 μm spacing. The undulating surfaces were nano-smooth, with height variations not exceeding 5–10 nm. These surface topography characteristics were distinctly different from those of the as-received samples, where broad valleys (up to 40–60 μm) were detected, whose inner surfaces exhibited asperities approximately 100 nm in height spaced at 1–2 μm. It was found that each of the three bacteria strains used in this study as adsorbates, viz. Staphylococcus aureus CIP 68.5, Pseudomonas aeruginosa ATCC 9025 and Escherichia coli K12, responded differently to the two types of titanium surfaces. Extreme grain refinement by ECAP resulted in substantially increased numbers of cells attached to the surface compared to as-received titanium. This enhanced degree of attachment was accompanied with an increased level of extracellular polymeric substances (EPS) production by the bacteria. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Description of Niveispirillum fermenti gen. nov., sp. nov., isolated from a fermentor in Taiwan,transfer of Azospirillum irakense (1989) as Niveispirillum irakense comb. nov., and reclassification of Azospirillum amazonense (1983) as Nitrospirillum amazonense gen. nov

A taxonomic study was carried out on a novel aerobic bacterial strain (designated CC-LY736^T) isolated from a fermentor in Taiwan. Cells of strain CC-LY736^T were Gram-stain negative, spiral-shaped and motile by means of a monopolar flagellum. Strain CC-LY736^T shared the greatest degree of 16S rRNA gene sequence similarity to Azospirillum irakense DSM 11586^T (97.2 %), Rhodocista centenaria JCM 21060^T (96.3 %) and Rhodocista pekingensis JCM 11669^T (96.1 %). The major fatty acids were C_16:0, C_16:1 ω5c, C_19:0 cyclo ω8c, C_18:1 ω7c/C_18:1 ω6c, C_16:0 3-OH and C_18:1 2-OH. The predominant polar lipids included phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidyldimethylethanolamine and two unidentified glycolipids. The common major respiratory quinone was ubiquinone Q-10 and predominant polyamines were sym-homospermidine and putrescine. The DNA G+C content of strain CC-LY736^T was 67.6 ± 0.1 mol %. During phylogenetic analysis, strain CC-LY736^T formed a unique phyletic lineage associated with Rhodocista species. However, the combination of genetic, chemotaxonomic and physiological data clearly indicated that strain CC-LY736^T was a novel representative of the family Rhodospirillaceae. Based on the polyphasic comparison, the name Niveispirillum fermenti gen. nov., sp. nov. is proposed; the type strain of the type species is CC-LY736^T (= BCRC 80504^T = LMG 27263^T). In addition, the reclassifications of Azospirillum irakense as Niveispirillum irakense comb. nov. (type strain KBC1^T = ATCC 51182^T = BCRC 15764^T = CIP 103311^T), and Azospirillum amazonense as Nitrospirillum amazonense gen. nov., sp. nov. (type strain Am14^T = ATCC 35119^T = BCRC 14279^T = DSM 3787^T) are proposed based on the polyphasic taxonomic data obtained in this study.     

Klebsiella michiganensis sp. nov., A New Bacterium Isolated from a Tooth Brush Holder

Isolate W14^T recovered from a household tooth brush holder was found to be gram-negative, a facultative anaerobic, non-motile, capsulated, and a non-endospore-forming straight rod. Based on phylogenetic analysis with 16S rRNA gene sequence, isolate W14^T was affiliated to the genus Klebsiella. The closest phylogenetic relative was K. oxytoca with 99 % similarity in the 16S rRNA gene sequence. The major whole-cell fatty acids were C_16:0 (31.23 %), C_18:1ω6c/C_18:1ω7c (21.10 %), and C_16:1ω7c/C_16:1ω6c (19.05 %). The sequence similarities of isolate W14^T based on rpoB, gyrA, and gyrB were 97, 98, and 98 % with K. oxytoca, and 97, 93, and 90 % with K. mobilis (=Enterobacter aerogenes), respectively. The ribotyping pattern showed a 0.46 similarity with K. oxytoca ATCC 13182^T and 0.24 with K. mobilis ATCC 13048^T. The DNA G+C content of isolate W14^T was 54.6 mol%. The DNA–DNA relatedness was 55.7 % with K. oxytoca ATCC 13182^T. Using the identification technology of MALDI-TOF mass spectrometry, the top matches for this isolate were K. oxytoca ATCC 13182^T (Match Factor Score 1.998) and K. mobilis (Score 1.797). On the basis of phenotypic, biochemical, chemotaxonomic, and molecular studies, isolate W14^T could be differentiated from other members of the genus Klebsiella including K. mobilis. Therefore, it is proposed that isolate W14^T (=ATCC BAA-2403^T=DSM 25444^T) should be classified as the type strain of a novel species of the genus Klebsiella, K. michiganensis sp. nov.     

<Emphasis Type="Italic">Escherichia coli,Pseudomonas aeruginosa</Emphasis>, and<Emphasis Type="Italic"> Staphylococcus aureus</Emphasis> Attachment Patterns on Glass Surfaces with Nanoscale Roughness

Attachment tendencies of Escherichia coli K12, Pseudomonas aeruginosa ATCC 9027, and Staphylococcus aureus CIP 68.5 onto glass surfaces of different degrees of nanometer-scale roughness have been studied. Contact-angle and surface-charge measurements, atomic force microscopy (AFM), scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM) were employed to characterize substrata and bacterial surfaces. Modification of the glass surface resulted in nanometer-scale changes in the surface topography, whereas the physicochemical characteristics of the surfaces remained almost constant. AFM analysis indicated that the overall surface roughness parameters were reduced by 60–70%. SEM, CLSM, and AFM analysis clearly demonstrates that although E. coli, P. aeruginosa and S. aureus present significantly different patterns of attachment, all of the species exhibited a greater propensity for adhesion to the “nano-smooth” surface. The bacteria responded to the surface modification with a remarkable change in cellular metabolic activity, as shown by the characteristic cell morphologies, production of extracellular polymeric substances, and an increase in the number of bacterial cells undergoing attachment.     

Paenibacillus taohuashanense sp. nov., a nitrogen-fixing species isolated from rhizosphere soil of the root of Caragana kansuensis Pojark

A nitrogen-fixing bacterium, designated strain gs65^T, was isolated from a rhizosphere soil sample of Caragana kansuensis Pojark. Phylogenetic analysis based on a fragment of the nifH gene and the full-length 16S rRNA gene sequence revealed that strain gs65^T is a member of the genus Paenibacillus. High levels of 16S rRNA gene similarity were found between strain gs65^T and Paenibacillus borealis DSM 13188^T (97.5 %), Paenibacillus odorifer ATCC BAA-93^T (97.3 %), Paenibacillus durus DSM 1735^T (97.0 %) and Paenibacillus sophorae DSM23020^T (96.9 %). Levels of 16S rRNA gene sequence similarity between strain gs65^T and the type strains of other recognized members of the genus Paenibacillus were below 97.0 %. Levels of DNA–DNA relatedness between strain gs65^T and P. borealis DSM 13188^T, P. odorifer ATCC BAA-93^T (97.3 %), P. durus DSM 1735^T and P. sophorae DSM23020^T were 35.9, 38.0, 34.2 and 35.5 % respectively. The DNA G+C content of strain gs65^T was determined to be 51.6 mol%. The major fatty acids were found to be iso-C_14:0, anteiso-C_15:0 and iso-C_16:0. On the basis of its phenotypic characteristics and levels of DNA–DNA hybridization, strain gs65^T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus taohuashanense sp. nov. is proposed. The type strain is gs65^T (=CGMCC 1.12175^T = DSM 25809^T).     

The influence of nanoscopically thin silver films on bacterial viability and attachment

The physicochemical and bactericidal properties of thin silver films have been analysed. Silver films of 3 and 150 nm thicknesses were fabricated using a magnetron sputtering thin-film deposition system. X-ray photoelectron and energy dispersive X-ray spectroscopy and atomic force microscopy analyses confirmed that the resulting surfaces were homogeneous, and that silver was the most abundant element present on both surfaces, being 45 and 53 at.% on the 3- and 150-nm films, respectively. Inductively coupled plasma time of flight mass spectroscopy (ICP-TOF-MS) was used to measure the concentration of silver ions released from these films. Concentrations of 0.9 and 5.2 ppb were detected for the 3- and 150-nm films, respectively. The surface wettability of the films remained nearly identical for both film thicknesses, displaying a static water contact angle of 95°, while the surface free energy of the 150-nm film was found to be slightly greater than that of the 3-nm film, being 28.8 and 23.9 mN m⁻¹, respectively. The two silver film thicknesses exhibited statistically significant differences in surface topographic profiles on the nanoscopic scale, with R _a, R _q and R _max values of 1.4, 1.8 and 15.4 nm for the 3-nm film and 0.8, 1.2 and 10.7 nm for the 150-nm film over a 5 × 5 μm scanning area. Confocal scanning laser microscopy and scanning electron microscopy revealed that the bactericidal activity of the 3-nm silver film was not significant, whereas the nanoscopically smoother 150-nm silver film exhibited appreciable bactericidal activity towards Pseudomonas aeruginosa ATCC 9027 cells and Staphylococcus aureus CIP 65.8 cells, obtaining up to 75% and 27% sterilisation effect, respectively.     

Non-toxic plant metabolites regulate Staphylococcus viability and biofilm formation: a natural therapeutic strategy useful in the treatment and prevention of skin infections

In the present study, the efficacy of generally recognised as safe (GRAS) antimicrobial plant metabolites in regulating the growth of Staphylococcus aureus and S. epidermidis was investigated. Thymol, carvacrol and eugenol showed the strongest antibacterial action against these microorganisms, at a subinhibitory concentration (SIC) of ≤ 50 μg ml^?1. Genistein, hydroquinone and resveratrol showed antimicrobial effects but with a wide concentration range (SIC = 50–1,000 μg ml^?1), while catechin, gallic acid, protocatechuic acid, p-hydroxybenzoic acid and cranberry extract were the most biologically compatible molecules (SIC ≥ 1000 μg ml^?1). Genistein, protocatechuic acid, cranberry extract, p-hydroxybenzoic acid and resveratrol also showed anti-biofilm activity against S. aureus, but not against S. epidermidis in which, surprisingly, these metabolites stimulated biofilm formation (between 35% and 1,200%). Binary combinations of cranberry extract and resveratrol with genistein, protocatechuic or p-hydroxibenzoic acid enhanced the stimulatory effect on S. epidermidis biofilm formation and maintained or even increased S. aureus anti-biofilm activity.     

Influence of lipopolysaccharides and lipids A from some marine bacteria on spontaneous and Escherichia coli LPS-induced TNF-α release from peripheral human blood cells

Some endotoxic properties of lipopolysaccharides (LPS) and lipids A (LA) from the marine bacteria Marinomonas communis ATCC 27118^T, Marinomonas mediterranea ATCC 700492^T, and Chryseobacterium indoltheticum CIP 103168^T were studied. The preparations tested were shown to have high 50% lethal doses (4 μg per mouse for LPS from M. mediterranea and more than 12 μg per mouse for two other LPS and LA from C. indoltheticum) and were moderate (371 ± 37 pg/ml at 10 μg/ml of C. indoltheticum LPS), weak (148 ± 5 pg/ml at 1 μg/ml of M. mediterranea LPS), and zero (LA and LPS from M. communis and LA from C. indoltheticum) inducers of tumor necrosis factor α (TNF-α) release from peripheral human blood cells. The capacity of the LA and LPS samples from marine bacteria to inhibit TNF-α release induced by LPS from Escherichia coli O55: B5 (10 ng/ml) was also studied. Published in Russian in Biokhimiya, 2006, Vol. 71, No. 7, pp. 936–944.     

Fine mechanisms of the interaction of silver nanoparticles with the cells of Salmonella typhimurium and Staphylococcus aureus

Silver nanoparticles possess antibacterial effect for various bacteria; however mechanisms of the interaction between Ag-NPs and bacterial cells remain unclear. The aim of our study was to obtain direct evidence of Ag-NPs penetration into cells of Gram-negative bacterium S. typhimurium and Gram-positive bacterium S. aureus, and to study cell responses to Ag-NPs. The Ag-NPs (most 8–10 nm) were obtained by gas-jet method. S. typhimurium (7.81 × 10⁷ CFU), or S. aureus (8.96 × 10⁷ CFU) were treated by Ag-NPs (0.05 mg/l of silver) in orbital shaker at 190 rpm, 37 °C. Bacteria were sampled at 0.5, 1, 1.5, 2, 5 and 23 h of the incubation for transmission electron microscopy of ultrathin sections. The Ag-NPs adsorbed on outer membrane of S. typhimurium and cell wall of S. auereus; penetrated and accumulated in cells without aggregation and damaging of neighboring cytoplasm. In cells of S. aureus Ag-NPs bound with DNA fibers. Cell responses to Ag-NPs differed morphologically in S. typhimurium and S. aureus, and mainly were presented by damage of cell structures. The cytoplasm of S. aureus became amorphous, while S. typhimurium showed lumping and lysis of cytoplasm which led to formation of “empty” cells. Other difference was fast change of cell shape in S. typhimurium, and late deformation of S. aureus cells. The obtained results showed how different could be responses induced by the same NPs in relatively simple prokaryotic cells. Evidently, Ag-NPs directly interact with macromolecular structures of living cells and are exert an active influence on their metabolism.     

Sphingomonas kyeonggiense sp. nov., isolated from soil of a ginseng field

A Gram-staining negative bacterium, THG-DT81^T, which was isolated from soil of a ginseng field, was investigated using a polyphasic taxonomic approach. Cells were oxidase- and catalase-positive, aerobic, rod-shaped and motile with one polar flagellum. Strain THG-DT81^T grew optimally at pH 7.0 and in the absence of NaCl on trypticase soy agar. Its optimum growth temperature was 25–28 °C. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain THG-DT81^T belongs to the family Sphingomonadaceae and was related to Sphingomonas pituitosa EDIV^T (98.0 % similarity), S. leidyi ATCC 15260^T (97.8 %), S. trueperi LMG 2142^T (97.1 %), S. azotifigens NBRC 15497^T (97.1 %), S. koreensis JSS26 ^T (97.1 %) and S. dokdonensis DS-4^T (97.0 %). Strain THG-DT81^T contained Q-10 as the predominant ubiquinone and C_18:1 ω7c and C_16:0 as the major fatty acids. The G+C content of the genomic DNA was determined to be 66.8 mol %. The major component in the polyamine pattern was identified as sym-homospermidine. The major polar lipids detected in strain THG-DT81^T were sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and phosphatidylcholine. The DNA–DNA relatedness values of the strain THG-DT81^T and its closest phylogenetically neighbors were below 21 %. The phenotypic characteristics and genotypic data demonstrated the affiliation of strain THG-DT81^T to the genus Sphingomonas. On the basis of the polyphasic taxonomic data presented, strain THG-DT81^T is described as a novel species of genus Sphingomonas, for which the name Sphingomonas kyeonggiense sp. nov. is proposed. The type strain is THG-DT81^T (= KACC 17173^T = JCM 18825^T).     

Characterization of Streptococcus sanguis Isolated from Patients with Behçet's Disease

The DNA homology and cell wall sugar constituents of eight Streptococcus sanguis(-like) strains, three isolated from the patients with Behçet's disease (BD114-23, BD113-20, BD118-1), two from patients with Kawasaki disease (MCLS-1, MCLS-2), and three type and reference strains of ATCC (ATCC10556^T: S. sanguis, ATCC10557: S. oralis, and ATCC10558^T: S. gordonii) were analyzed. Strains BD114-23 and BD118-1 showed high DNA homology to ATCC10556^T, and their cell wall constituents were identical. Conversely, BD113-20, MCLS-1, MCLS-2, and ATCC10557 showed little DNA homology to ATCC10556^T and ATCC10558^T, but showed approximately 50 to 60% homology to each other. The cell wall constituents of BD113-20, MCLS-1, MCLS-2, and ATCC10557, however, were somewhat different, indicating that some of the clinical isolates have different characters from those of the three ATCC strains.     

A new <Emphasis Type="Italic">Streptomyces</Emphasis> strain isolated from Saharan soil produces di-(2-ethylhexyl) phthalate,a metabolite active against methicillin-resistant <Emphasis Type="Italic">Staphylococcus aureus</Emphasis>

An actinomycete strain designated G60 was isolated from a Saharan soil sample in Ghardaïa, Algeria, by a dilution agar plating method using chitin-vitamin agar medium supplemented with penicillin. Morphological and chemical studies indicated that this strain belonged to the genus Streptomyces. Analysis of the 16S rDNA sequence showed an identity level within Streptomyces species, with S. coerulescens ISP 5146^T and S. bellus ISP 5185^T the most closely related (100 % for each). However, the comparison of the morphological and physiological characteristics of the strain with those of the two nearest species showed significant differences. Strain G60 had a very strong activity against pathogenic staphylococci, including methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300, other clinical isolates of MRSA and vancomycin resistant S. aureus (VRSA) S1. One antimicrobial compound was extracted by n-hexane from the ISP2 culture medium at 5 days of fermentation culture and purified by HPLC. The chemical structure of the compound was determined after spectroscopic (¹H NMR, ¹³C NMR, ¹H-¹H COSY and ¹H-¹³C HMBC spectra), and spectrometric (mass spectrum) analyses. The bioactive compound was identified as di-(2-ethylhexyl) phthalate.     

Detection of Malaysian methicillin-resistant <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> (MRSA) clinical isolates using simplex and duplex real-time PCR

The aim of this study was to develop a methicillin-resistant Staphylococcus aureus (MRSA) detection method based on the melting temperature analysis profiling of S. aureus clinical isolates from three different hospitals in Malaysia. Simplex and duplex real-time PCR assay was used for the simultaneous detection of nuc (species-specific) and mecA (methicillin-resistance) genes in a single SYBR Green I real-time PCR tube assay. Evaluations were based on the melting temperature (T _m) analysis of the amplicons using 23 S. aureus clinical isolates including three ATCC S. aureus standard strains. Real-time PCR amplification products with melting peaks at 78.39 ± 0.4°C and 74.41 ± 0.6°C were detected for nuc and mecA genes, respectively. Each real-time PCR assay was completed within two hours. This rapid genotypic method is useful for the detection of resistant determinant (mecA) and identification of S. aureus (nuc) clinical isolates, thus benefiting patient therapy in hospitals.     

Effect of Ottoman Viper (Montivipera xanthina (Gray, 1849)) Venom on Various Cancer Cells and on Microorganisms

Cytotoxic and antimicrobial effects of Montivipera xanthina venom against LNCaP, MCF-7, HT-29, Saos-2, Hep3B, Vero cells and antimicrobial activity against selected bacterial and fungal species: Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, E. coli O157H7, Enterococcus faecalis 29212, Enterococcus faecium DSM 13590, Staphylococcus epidermidis ATCC 12228, S. typhimirium CCM 5445, Proteus vulgaris ATCC 6957 and Candida albicans ATCC 10239 were studied for evaluating the potential medical benefit of this snake venom. Cytotoxicity of venom was determined using MTT assay. Snake venom cytotoxicity was expressed as the venom dose that killed 50 % of the cells (IC₅₀). The antimicrobial activity of venom was studied by minimal inhibitory concentration (MIC) and disc diffusion assay. MIC was determined using broth dilution method. The estimated IC₅₀ values of venom varied from 3.8 to 12.7 or from 1.9 to 7.2 μg/ml after treatment with crude venom for 24 or 48 h for LNCaP, MCF-7, HT-29 and Saos-2 cells. There was no observable cytotoxic effect on Hep3B and Vero cells. Venom exhibited the most potent activity against C. albicans (MIC, 7.8 μg/ml and minimal fungicidal concentration, 62.5 μg/ml) and S. aureus (MIC, 31.25 μg/ml). This study is the first report showing the potential of M. xanthina venom as an alternative therapeutic approach due to its cytotoxic and antimicrobial effects.     

Burkholderia caballeronis sp. nov., a nitrogen fixing species isolated from tomato (Lycopersicon esculentum) with the ability to effectively nodulate Phaseolus vulgaris

During a survey of Burkholderia species with potential use in agrobiotechnology, a group of 12 strains was isolated from the rhizosphere and rhizoplane of tomato plants growing in Mexico (Nepantla, Mexico State). A phylogenetic analysis of 16S rRNA gene sequences showed that the strains are related to Burkholderia kururiensis and Burkholderia mimosarum (97.4 and 97.1 %, respectively). However, they induced effective nitrogen-fixing nodules on roots of Phaseolus vulgaris. Based on polyphasic taxonomy, the group of strains represents a novel species for which the name Burkholderia caballeronis sp. nov. is proposed. The type species is TNe-841^T (= LMG 26416^T = CIP 110324^T).     

Description of Geodermatophilus amargosae sp. nov., to Accommodate the Not Validly Named Geodermatophilus obscurus subsp. amargosae (Luedemann, 1968)

A novel, gram reaction positive aerobic actinobacterium, designated G12^T, not validly named as Geodermatophilus obscurus subsp. amargosae, was accessed in the DSMZ open collection as DSM 46136^T. The optimal growth was at 2,535 °C, at pH 6.0–12.0 and in the absence of NaCl, forming greenish-black-coloured colonies on GYM agar. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Geodermatophilus. The DNA G+C content of the strain was 73.0 mol%. The peptidoglycan contained meso-diaminopimelic acid as diagnostic diamino acid. The main phospholipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and a small amount of phosphatidylglycerol; MK-9(H₄) was the dominant menaquinone and galactose was detected as a diagnostic sugar. The major cellular fatty acid was branched-chain saturated acid iso-C_15:0. The 16S rRNA gene showed 94.2–99.5 % sequence identity with the members of the genus Geodermatophilus. Based on the chemotaxonomic results and 16S rRNA gene sequence analysis, strain G12^T is proposed to represent a novel species, Geodermatophilus amargosae. Type strain is G12^T [=G96] (=DSM 46136^T = CCUG 62971^T = MTCC 11559^T = ATCC 25081^T = JCM 3153^T = NBRC 13316^T = NRRL B-3578^T = KCTC 9360^T). The INSDC accession number is HF679056.