Tannockella kyphosi gen. nov., sp. nov., a member of the family Erysipelotrichaceae, isolated from the hindgut of the marine herbivorous fish Kyphosus sydneyanus.

A Gram-stain-positive, non-spore-forming, rod-shaped, obligately anaerobic bacterium, designated strain BP52GT, was isolated from the hindgut of a Silver Drummer (Kyphosus sydneyanus) fish collected from the Hauraki Gulf, New Zealand. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the isolate belonged to the family Erysipelotrichaceae in the phylum Firmicutes and was most closely related to Clostridium saccharogumia with 93.3 % sequence identity. Isolate BP52GT grew on agar medium containing mannitol as the sole carbon source. White, opaque and shiny colonies of the isolate measuring approximately 1 mm diameter grew within a week at 20-28 °C (optimum, 24 °C) and pH 6.9-8.5 (optimum, pH 7.8). BP52GT tolerated the addition of up to 1 % NaCl to the medium. Formate and acetate were the major fermentation products. The major cellular fatty acids were C16 : 0, C16:1n-7t and C18:1n-7t. The genome sequence of the isolate was determined. Its G+C content was 30.7 mol%, and the 72.65 % average nucleotide identity of the BP52GT genome to its closest neighbour with a completely sequenced genome (Erysipelatoclostridium ramosum JCM 1298T) indicated low genomic relatedness. Based on the phenotypic and taxonomic characteristics observed in this study, a novel genus and species Tannockella kyphosi gen. nov., sp. nov. is proposed for isolate BP52GT (=NZRM 4757T=JCM 34692T).

Absicoccus porci gen. nov., sp. nov., a member of the family Erysipelotrichaceae isolated from pig faeces.

An obligately anaerobic, Gram-stain-positive and coccus-shaped bacterium, designated strain YH-panp20T, was isolated from pig faeces. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the isolate belongs to the family Erysipelotrichaceae, and is most closely related to Catenisphaera adipataccumulans KCTC 15517T (93.5 % sequence similarity), followed by Faecalitalea cylindroides KCTC 5815T (92.2 %), Faecalicoccus acidiformans KCTC 15521T (90.2 %) and Holdemanella biformis KCTC 5969T (89.6 %). Average nucleotide identity values between YH-panp20T and its closest relatives were lower than 71 %. The G+C content of the isolate was 38.4 mol%, and its cell-wall peptidoglycan was found to be of A1γ type and contained meso-diaminopimelic acid. The predominant fatty acids were C18 : 1 cis 9, C18 : 0 DMA and C16 : 0. The major end-products of glucose fermentation were lactate, acetate and formate. Therefore, based on the phenotypic, phylogenetic and chemotaxonomic properties, a novel genus and species, Absicoccus porci gen. nov., sp. nov., is proposed for isolate YH-panp20T (=KCTC 15747T=JCM 32769T).

Clinical Significance of Commensal Gram-Positive Rods Routinely Isolated from Patient Samples.

Commensal bacteria from the skin and mucosal surfaces are routinely isolated from patient samples and considered contaminants. The majority of these isolates are catalase-positive Gram-positive rods from multiple genera routinely classified as diphtheroids. These organisms can be seen upon Gram staining of clinical specimens or can be isolated as the predominant or pure species in culture, raising a priori suspicion of a possible involvement in infection. With the development and adoption of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), suspicious isolates are now routinely identified to the species level. In this study, we performed a retrospective data review (2012 to 2015) and utilized site-specific laboratory criteria and chart reviews to identify species within the diphtheroid classification representative of true infection versus contamination. Our data set included 762 isolates from 13 genera constituting 41 bacterial species. Only 18% represented true infection, and 82% were deemed contaminants. Clinically significant isolates were identified in anaerobic wounds (18%), aerobic wounds (30%), blood (5.5%), urine (22%), cerebrospinal fluid (24%), ophthalmologic cultures (8%), and sterile sites (20%). Organisms deemed clinically significant included multiple Actinomyces species in wounds, Propionibacterium species in joints and cerebrospinal fluid associated with central nervous system hardware, Corynebacterium kroppenstedtii (100%) in breast, and Corynebacterium striatum in multiple sites. Novel findings include clinically significant urinary tract infections by Actinomyces neuii (21%) and Corynebacterium aurimucosum (21%). Taken together, these findings indicate that species-level identification of diphtheroids isolated with a priori suspicion of infection is essential to accurately determine whether an isolate belongs to a species associated with specific types of infection.

Aliifodinibius halophilus sp. nov., a moderately halophilic member of the genus Aliifodinibius, and proposal of Balneolaceae fam. nov.

A novel Gram-stain-negative, rod-shaped, facultatively anaerobic, oxidase-negative and catalase-positive bacterium, designated 2W32T, was isolated from a marine solar saltern on the coast of Weihai, Shandong Province, China. Strain 2W32T was tolerant to moderate salt conditions. Optimal growth occurred at 33-37 °C (range 20-45 °C) and pH 7.5-8.0 (range pH 7.0-8.5) with 6-10 % (w/v) NaCl (range 2-18 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 2W32T shared highest similarity with Aliifodinibius sediminis YIM J21T (94.6 %), Aliifodinibius roseus YIM D15T (94.4 %), Fodinibius salinus YIM C003T (93.6 %), Gracilimonas tropica CL-CB462T (88.6 %) and Balneola vulgaris 13IX/A01/164T (86.4 %) and less than 83.0 % similarity with other species of the phylum Bacteroidetes. The isolate and closely related species formed a novel family-level clade in the phylum Bacteroidetes. The polar lipid profile of the novel isolate consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified aminolipid, an unidentified glycolipid and an unidentified lipid. The dominant cellular fatty acids (>10 %) were iso-C15 : 0, iso-C17 : 1ω9c and summed feature 3 (C16:1ω7c and/or iso-C15 : 0 2-OH) and the sole respiratory quinone was menaquinone 7 (MK-7). The DNA G+C content of strain 2W32T was 47.5 mol %. Comparative analysis of 16S rRNA gene sequences and characterization indicated that strain 2W32T represents a novel species within the genus Aliifodinibius, for which the name Aliifodinibius halophilus sp. nov. is proposed. The type strain is 2W32T (=KCTC 42497T=CICC 23869T). In addition, a novel family, Balneolaceae fam. nov., is proposed to accommodate the genera Fodinibius, Aliifodinibius, Gracilimonas and Balneola.

Caldicellulosiruptor changbaiensis sp. nov., a cellulolytic and hydrogen-producing bacterium from a hot spring.

A novel thermophilic bacterial strain, CBS-Z(T), was isolated from a terrestrial hot spring in the Changbai Mountains, PR China. Cells of strain CBS-Z(T) were short straight rods without flagella and had Gram-positive cell walls. Growth was observed at 40-90 °C (optimum 75 °C) and at pH 5.6-8.6 (optimum pH 7.8). The primary end-products from the fermentation of filter paper by strain CBS-Z(T) were acetate, lactate, H2, and CO2. The main cellular fatty acids were iso-C17:0, iso-C14:0 3-OH and C16:0. The G+C content of the genomic DNA was 36.08 mol%. Multiple sequence alignment of the 16S rRNA gene sequence and phylogenetic analyses indicated that strain CBS-Z(T) belongs to the genus Caldicellulosiruptor and the most similar micro-organism was Caldicellulosiruptor saccharolyticus DSM 8903(T) (96.36% 16S rRNA gene sequence similarity); the 16S rRNA gene sequence similarity of strain CBS-Z(T) to other species was below 95%. Based on its phylogenetic and phenotypic characteristics, strain CBS-Z(T) represents a novel species of the genus Caldicellulosiruptor, for which the name Caldicellulosiruptor changbaiensis sp. nov. is proposed. The type strain is CBS-Z(T) ( =DSM 26941(T) =CGMCC 1.5180(T)).

Ammoniibacillus agariperforans gen. nov., sp. nov., a thermophilic, agar-degrading bacterium isolated from compost.

A thermophilic, agar-degrading bacterium, strain FAB2(T), was isolated from sewage sludge compost. According to phylogenetic analysis based on 16S rRNA gene sequences, strain FAB2(T) belonged to the family Paenibacillaceae within the phylum Firmicutes. However, FAB2(T) was different enough at the genus level from closely related species. The percentages of 16S rRNA gene sequence similarity with related organisms were 90.4 % for Thermobacillus xylanilyticus, 91.8 % for Paenibacillus barengoltzii, 89.4 % for Cohnella lupini, 90.1 % for Fontibacillus aquaticus, and 89.0 % for Saccharibacillus sacchari. Morphological and physiological analyses revealed that the strain was motile, rod-shaped, Gram-stain-positive, aerobic and able to form oval endospores in swollen sporangia. Ammonium was required as a nitrogen source while nitrate, nitrite, urea and glutamate were not utilized. Catalase and oxidase activities were weakly positive and positive, respectively. The bacterium grew in the temperature range of 50-65 °C and in media with pH 7.5 to 9.0. Optimal growth occurred at 60 °C and pH 8.0-8.6. Growth was inhibited at pH≤7.0 and NaCl concentrations ≥2.5 % (w/v). In chemotaxonomic characterization, MK-7 was identified as the dominant menaquinone. Major fatty acids were iso-C16 : 0 and C16 : 0. Dominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phosphatidylcholine was present in a moderate amount. The diamino acid in the cell wall was meso-diaminopimelic acid. The G+C content of the genomic DNA was 49.5 mol% in a nucleic acid study. On the basis of genetic and phenotypic characteristics, strain FAB2(T) ( = NBRC 109510(T) = KCTC 33130(T)) showed characteristics suitable for classification as the type strain of a novel species of a new genus in the family Paenibacillaceae, for which the name Ammoniibacillus agariperforans gen. nov., sp. nov. is proposed.

Catenisphaera adipataccumulans gen. nov., sp. nov., a member of the family Erysipelotrichaceae isolated from an anaerobic digester.

An obligately anaerobic bacterium, designated strain GK12(T), was isolated from an anaerobic digester in Fukagawa, Hokkaido Prefecture, Japan. The cells of strain GK12(T) were non-motile, non-spore-forming cocci that commonly occurred in chains. 16S rRNA gene sequence analysis revealed that strain GK12(T) was affiliated with the family Erysipelotrichaceae in the phylum Firmicutes and showed 91.8 % sequence similarity to the most closely related species, Faecalicoccus acidiformans. The strain grew at 30-50 °C (optimally at 40 °C) and at pH 5.5-8.5 (optimally at pH 7.5). The main end product of glucose fermentation was lactate. Yeast extract was required for growth. The strain contained C14 : 0, C14 : 0 1,1-dimethoxyalkane (DMA), C16 : 0 DMA and C18 : 0 DMA as the major cellular fatty acids (>10 % of the total). The polar lipid profile was composed of phosphatidylglycerol, phosphatidylinositol and an unidentified phospholipid. The whole-cell sugars were galactose, rhamnose and ribose. The cell-wall murein contained alanine, glutamic acid, lysine, serine and threonine, but not diaminopimelic acid. The G+C content of the genomic DNA was 47.7 mol%. Based on phenotypic, phylogenetic and chemotaxonomic properties, a novel genus and species, Catenisphaera adipataccumulans gen. nov., sp. nov., is proposed to accommodate strain GK12(T) ( = NBRC 108915(T) = DSM 25799(T)).

Halanaerobium sehlinense sp. nov., an extremely halophilic, fermentative, strictly anaerobic bacterium from sediments of the hypersaline lake Sehline Sebkha.

A strictly anaerobic, extremely halophilic, Gram-positive, rod-shaped bacterium was isolated from the hypersaline (>20% NaCl) surface sediments of Sehline Sebkha in Tunisia. The strain, designated 1Sehel(T), was strictly halophilic and proliferated at NaCl concentrations of between 5% and 30% (saturation), with optimal growth at 20% NaCl. Strain 1Sehel(T) was non-spore-forming, non-motile, appearing singly or in pairs, or occasionally as long chains and measured 0.5-0.8 µm by 3-10 µm. Strain 1Sehel(T) grew optimally at pH values of 7.4 but had a very broad pH range for growth (pH 5.2-9.4). It grew at temperatures between 20 and 50 °C with an optimum at 43 °C. Strain 1Sehel(T) required yeast extract for growth. The isolate fermented glucose, galactose, fructose, glycerol, mannose, maltose, ribose, pyruvate and sucrose. The fermentation products from glucose utilization were lactate, acetate, formate, ethanol, CO2 and H2. The G+C ratio of the DNA was 32.7 mol%. The major fatty acids were C15:1ω6c/7c, C16:1ω7c, C16:0 and C15:0. On the basis of phylogenetic and physiological properties, strain 1Sehel(T) (=DSM 25582(T)=JCM 18213(T)) is proposed as the type strain of Halanaerobium sehlinense sp. nov., within the family Halanaerobiaceae.

Tumebacillus flagellatus sp. nov., an α-amylase/pullulanase-producing bacterium isolated from cassava wastewater.

A novel α-amylase/pullulanase-producing bacterium, designated strain GST4(T), was isolated from samples collected from the wastewater of a cassava starch factory in Nanning, Guangxi Autonomous Region, southern China. Cells of strain GST4(T) were rod-shaped bacilli containing ellipsoidal terminal spores and found to be Gram-reaction-positive, aerobic, motile, oxidase-positive, catalase-negative and formed light yellow colonies on agar plates. Strain GST4(T) was able to grow at pH 4.5-8.5 (optimum at pH 5.5), temperatures ranging from 20 to 42 °C (optimum at 37 °C) and salt concentrations of 0-1% (w/v) NaCl (optimum at 0.5%, w/v) on R2A medium. Strain GST4(T) grew heterotrophically on complex carbon substrates and chemolithoautotrophically on inorganic sulfur compounds, as demonstrated by growth on sodium thiosulfate and sulfite as sole electron donors. It can reduce nitrate and nitrite. Strain GST4(T) contained iso-C(15:0) and anteiso-C(15:0) as the major cellular fatty acids and menaquinone 7 (MK-7) as the major respiratory quinone. The cell-wall peptidoglycan was of type A1γ. The genomic DNA G+C content of strain GST4(T) was 53.7 mol%. Physiological and chemotaxonomic characteristics combined with phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GST4(T) was a member of the genus Tumebacillus and most closely related to Tumebacillus permanentifrigoris DSM 18773(T) and Tumebacillus ginsengisoli DSM 18389(T) with 97.3 and 94.5% sequence similarity, respectively. The DNA-DNA relatedness values between strain GST4(T) and T. permanentifrigoris DSM 18773(T), and strain GST4(T) and T. ginsengisoli DSM 18389(T) were 44.0 and 60.4%, respectively. The new isolate differed from those species of the genus Tumebacillus in that it has peritrichous flagella for motility. Based on the evidence obtained from this study, strain GST4(T) represents a novel species of the genus Tumebacillus, for which the name Tumebacillus flagellatus sp. nov. is proposed. The type strain is GST4(T) ( =CGMCC 1.12170(T) =DSM 25748(T)).

Analysis of the intraimplant microflora of two-piece dental implants.

OBJECTIVE: Information about the spectrum of microorganisms in the intraimplant cavities of two-piece dental implants is scarce. The purpose of this study was to assess the intraimplant microflora of two-piece dental implants by conventional biochemical testing, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 16 s rDNA gene sequencing. MATERIALS AND METHODS: Ten patients (six men and four women; average age = 66.7 years; age range = 58-78 years) received 35 two-piece titanium implants carrying ball attachments. Biofilm sampling was performed with sterile microbrushes, and nonadherent microbial samples were obtained by injection and reuptake of predefined volumes of NaCl solution. The samples were cultured and analyzed by conventional biochemical testing, MALDI-TOF MS, and 16 s rDNA gene sequencing. RESULTS: Of the 103 species detected, 27 and 33 were identified only in the biofilm and nonadherent microbial samples, respectively. Forty-three species were identified in both types of samples. CONCLUSIONS: Two-piece dental implants harbored a broad spectrum of gram-positive and gram-negative aerobes and anaerobes, especially rods and cocci. CLINICAL RELEVANCE: These findings confirm bacterial translocation from the oral cavity to intraimplant cavities. Microbiological methods as used in this study are necessary to reveal the complete vital microflora of intraimplant cavities.

Exiguobacterium aquaticum sp. nov., a member of the genus Exiguobacterium.

A Gram-positive, motile, short rod-shaped, orange pigmented bacterium, designated strain IMTB-3094(T), was isolated from a water sample collected from Tikkar Tal Lake, Haryana, and subjected to detailed polyphasic taxonomic analysis. Strain IMTB-3094(T) possessed most of the phenotypic and chemotaxonomic properties of the genus Exiguobacterium and, based on 16S rRNA gene sequence analysis, was assigned to this genus. Strain IMTB-3094(T) exhibited the highest 16S rRNA gene sequence similarity to Exiguobacterium mexicanum MTCC 7759(T) (99.5 %) followed by Exiguobacterium aurantiacum MTCC 6414(T) (99.1 %), Exiguobacterium aestuarii MTCC 7750(T) (98.0 %), Exiguobacterium profundum MTCC 10851(T) (98.0 %) and Exiguobacterium marinum MTCC 7751(T) (98.0 %). The G+C content of the genomic DNA of strain IMTB-3094(T) was 53.2 mol% and a DNA-DNA relatedness study confirmed that it represents a novel species. The major fatty acids of strain IMTB-3094(T) were iso-C(17 : 0) (16.1 %), anteiso-C(13 : 0) (19.0 %), iso-C(13 : 0) (11.9 %), iso-C(15 : 0) (9.8 %) and iso-C(17 : 1) (12.7 %). The predominant quinones were MK-7 (55.0 %) and MK-6 (26.0 %) with minor amounts of MK-8 (12.0 %). Based on phenotypic, chemotaxonomic and phylogenetic analyses, strain IMTB-3094(T) represents a novel species of the genus Exiguobacterium, for which the name Exiguobacterium aquaticum sp. nov. is proposed. The type strain is IMTB-3094(T) (= MTCC 10958(T) = JCM 17977(T)).

Clostridium saccharogumia sp. nov. and Lactonifactor longoviformis gen. nov., sp. nov., two novel human faecal bacteria involved in the conversion of the dietary phytoestrogen secoisolariciresinol diglucoside.

Two anaerobic bacteria involved in the conversion of the plant lignan secoisolariciresinol diglucoside were isolated from faeces of a healthy male adult. The first isolate, strain SDG-Mt85-3Db, was a mesophilic strictly anaerobic Gram-positive helically coiled rod. Based on 16S r RNA gene sequence analysis, its nearest relatives were Clostridium cocleatum (96.7% similarity) and Clostridium ramosum (96.6%). In contrast to these species, the isolate was devoid of alpha-galactosidase and -glucosidase and did not grow on maltose, melibiose, raffinose, rhamnose and trehalose. The hypothesis that strain SDG-Mt85-3Db represents a new bacterial species of the Clostridium cluster XVIII was confirmed by DNA-DNA hybridisation experiments. The G+C content of DNA of strain SDG-Mt85-3Db (30.7+/-0.8 mol%) was comparable with that of Clostridium butyricum, the type species of the genus Clostridium. The name Clostridium saccharogumia is proposed for strain SDG-Mt85-3Db (=DSM 17460T=CCUG 51486T). The second isolate, strain ED-Mt61/PYG-s6, was a mesophilic strictly anaerobic Gram-positive regular rod. Based on 16S rRNA gene sequence analysis, its nearest relatives were Clostridium amygdalinum (93.3%), Clostridium saccharolyticum (93.1%) and Ruminococcus productus (93.0%). The isolate differed from these species in its ability to dehydrogenate enterodiol. It also possessed alpha-arabinosidase and -galactosidase and had a higher G+C content of DNA (48.0 mol%). According to these findings, it is proposed to create a novel genus, Lactonifactor, and a novel species, Lactonifactor longoviformis, to accommodate strain ED-Mt61/PYG-s6. The type strain is DSM 17459T (=CCUG 51487T).

[A new hydrogen-producing strain and its characterization of hydrogen production].

An anaerobic, thermophilic, hydrogen-producing strain T42 was obtained from a hot spring of South Mountain District, Tibet. Cells are Gram-positive, mobile rod-shaped. Spores were not observed. Temperature range for growth is 32 degrees C to 69 degrees C (optimum temperature, 60 degrees C - 62 degrees C), and pH range for growth is 5.0 to 8.8 (optimum pH, 7.0 - 7.5). The generation time is around 30 min. Organic nitrogen sourc is required for growth. Strain T42 utilizes a wide range of carbohydrates, including starch, dextrin, sucrose, cellobiose, fructose, maltose, ribose, glycogen and galactose. Acetate, ethanol, H2 and CO2 are the end products of glucose fermentation. The (G + C) content of strain T42 is 31.2 mol%. Phylogenetic analysis based on the 16S rDNA sequence similarity indicates that strain T42 is the closest relative to Thermobrachium celere and Caloramator indicus. Biological characteristics and phylogenetic analysis of the 16S rDNA gene indicate the new strain belongs to the genus Thermobrachium. Strain T42 produces H2 from glucose at maximal level when growing at 62 degrees C and initial pH 7.2, the hydrogen yields and maximal hydrogen production rate are 1.06 mol H2/mol glucose and 24.0 mmol H2/gDW/h, respectively. Strain T42 also produced H2 by fermentating from a variety of carbohydrates. 20 mmol/L Magnesium and 2 mmol/L iron increase the hydrogen production content by 20% and 23.3%, respectively, but nickel has no effect on the hydrogen production. In the co-culture of strain T42 and methane-producing strain M. thermautotrophicus Z245, hydrogen pressure is dramatically decreased, meanwhile deduced H2 production and the consumption of glucose are increased markedly by 2.8 fold and 1 fold, and the ratio of acetate/ethanol is enhanced froml to 1.7.

The Na(+) cycle in Acetobacterium woodii: identification and characterization of a Na(+) translocating F(1)F(0)-ATPase with a mixed oligomer of 8 and 16 kDa proteolipids.

The homoacetogenic bacterium Acetobacterium woodii relies on a sodium ion current across its cytoplasmic membrane for energy-dependent reactions. The sodium ion potential is established by a yet to be identified primary, electrogenic pump connected to the Wood-Ljungdahl pathway. Reactions possibly involved in Na(+) export are discussed. The electrochemical sodium ion potential generated is used to drive endergonic reactions such as flagellar rotation and ATP synthesis. Biochemical and molecular data identified the Na(+)-ATPase of A. woodii as a typical member of the F(1)F(0) class of ATPases. Its catalytic properties and the hypothetical sodium ion binding site in subunit c are discussed. The encoding genes were cloned and, surprisingly, the atp operon was shown to contain multiple copies of genes encoding subunit c. Two copies encode identical 8 kDa proteolipids, and a third copy arose by duplication and subsequent fusion of two genes. Furthermore, the duplicated subunit c does not contain the ion binding site in hair pin two. Biochemical and molecular data revealed that all three copies of subunit c constitute a mixed oligomer. The evolution of the structure and function of subunit c in ATPases from eucarya, bacteria, and archaea is discussed.

Thermophilic bacteria in Moroccan hot springs, salt marshes and desert soils.

The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. subtilis (subsp. spizizenii (2) and subsp. inaquosurum (6)), B. amyloliquefaciens (subsp. amyloliquefaciens (4) and subsp. plantarum (4)), B. tequilensis (3), B. pumilus (3) and Bacillus sp. (19). Only six isolates (2.5%) belonged to the genus Aeribacillus represented by A. pallidus (4) and Aeribacillus sp. (2). In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively.

Heterogeneric conjugal transfer of the pheromone-responsive plasmid pIP964 (IncHlyI) of Enterococcus faecalis in the apparent absence of pheromone induction.

Erythromycin-resistant derivatives of the pheromone-responsive plasmid pIP964 from Enterococcus faecalis were constructed to study its host range. This was done by inserting the integrative vector pAT112 and the related replicon pTCR1 harboring oriR of the broad host range plasmid pAM beta 1 into the hemolysin-bacteriocin operon of pIP964, to give pTCR2 and pTCR3, respectively. Plasmid pTCR2 was transferred by filter matings from E. faecalis to Enterococcus faecium and Listeria monocytogenes at frequencies of 2 x 10(-7) and 5 x 10(-7) per donor, respectively, in the apparent absence of pheromone induction and cellular aggregation. In these hosts, pTCR2 remained intact as a self-replicating element and maintained its transfer capabilities. Plasmid pTCR3, but not pTCR2, was transferred at similar frequencies from E. faecalis to Lactococcus lactis and Streptococcus agalactiae. Thus, the transfer system of pIP964 possesses a broader host-range than its replication system.

[A Carnobacterium-like organism isolated form a patient with multiple bacterial synergistic gangrene].

An atypical lactic-acid producing gram positive rod Y6 strain was studied in this report, which was isolated form clinic sample of a patient with multiple bacterial synergistic gangrene, and could not be identified by routine method. A 1.5 kb of 16S rDNA of Y6 strain was synthesized and sequenced. Comparative 16S rDNA sequence analyses revealed that stain Y6 is most closely related to the genus of Carnobacterium. The overall similarity value between Y6 strain and Carnobacterium species are 93% to 97%. The signature nucleotides in 16S rDNA primary sequence of strain Y6 and that of genus of Carnobacterium were identical. The biological features of Y6 strain are very similar to that of Carnobacterium, such as lactic acid as main end product of in PYG broth, no gas produced form fermentation of glucose, catalase negative, no motility. Data suggested that Y6 strain is very similar to the genus of Carnobacterium, of which no strain has been isolated form clinical sample so far. Based on the results obtained, we names Y6 strain as Carnobacterium-like organism.

The microbial flora in the nasal septum area prone to perforation.

To explore the colonizing bacterial flora of the nasal septum area, that is mostly afflicted by perforations, 101 healthy police students had swab samples taken from that location. The described culture strategy recovered positive cultures from 95% of the test subjects and from 60% with more than one organism. In total, 191 bacterial isolates were classified according to colony morphology, Gram-stain and a panel of standard laboratory techniques. A part of the bacteria was identified to species-level by biochemical methods and by sequencing of the 16S rRNA gene. The predominant finding was Gram-positive irregular rods - 65 presumptive Corynebacterium isolates, both lipophilic and non-lipophilic, and 37 anaerobic Propionibacterium isolates. The second largest bacterial group was Gram-positive catalase-positive cocci, of which 13 isolates were identified as Staphylococcus aureus and 53 as coagulase-negative staphylococci. The few potential airway pathogens included Streptococcus pneumonia (n = 1) and Moraxella catarrhalis (n = 3) isolates. The bacterial flora colonizing the nasal septum mainly consists of Gram-positive bacteria. Although of low virulence, the microbial flora may impact on occlusion treatment of nasal septum perforations with silicone obturators.

Performance and microbial community analysis of two-stage process with extreme thermophilic hydrogen and thermophilic methane production from hydrolysate in UASB reactors.

The two-stage process for extreme thermophilic hydrogen and thermophilic methane production from wheat straw hydrolysate was investigated in up-flow anaerobic sludge bed (UASB) reactors. Specific hydrogen and methane yields of 89 ml-H(2)/g-VS (190 ml-H(2)/g-sugars) and 307 ml-CH(4)/g-VS, respectively were achieved simultaneously with the overall VS removal efficiency of 81% by operating with total hydraulic retention time (HRT) of 4 days . The energy conversion efficiency was dramatically increased from only 7.5% in the hydrogen stage to 87.5% of the potential energy from hydrolysate, corresponding to total energy of 13.4 kJ/g-VS. Dominant hydrogen-producing bacteria in the H(2)-UASB reactor were Thermoanaerobacter wiegelii, Caldanaerobacter subteraneus, and Caloramator fervidus. Meanwhile, the CH(4)-UASB reactor was dominated with methanogens of Methanosarcina mazei and Methanothermobacter defluvii. The results from this study suggest the two stage anaerobic process can be effectively used for energy recovery and for stabilization of hydrolysate at anaerobic conditions.

A pilot study: microbiological conditions of the oral cavity in minipigs for peri-implantitis models.

As peri-implantitis is an emerging problem, the development of validated animal models is mandatory. The aim of this pilot study was to provide a first step in describing the normal oral flora of minipigs. In five minipigs, samples of the oral flora were collected with sterile cotton swabs from the buccal gingiva of the lower jaw. Two swabs per animal were collected, followed by bacterial isolation under both aerobe and anaerobe conditions. Microbiological analyses included biochemical tests, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rDNA gene sequence analysis. A total of 61 taxa were detected, 14-21 different bacterial taxa from each minipig. Among the Gram-positive cocci, mainly staphylococcal and streptococcal species were identified. Different Actinomyces species were the most abundant taxa in the group of Gram-positive rods. Among the anaerobic bacteria, the Gram-negative genera Fusobacterium, Bacteroides and Prevotella were the most often observed taxa. This is the first study which begins to describe the normal oral flora in minipigs in cultures to allow for the detection of a broad spectrum. Several bacterial species identified are different from human ones. No specific species for peri-implantitis could be detected in that healthy sample.