Biomedical subjects

Marc Vancanneyt

Publications and source records attributed to Marc Vancanneyt.

At least 73 records · Page 4Linked to original sources

PubMed2004

Streptomyces glauciniger sp. nov., a novel mesophilic streptomycete isolated from soil in south China.

A polyphasic study was undertaken to establish the taxonomic status of a soil isolate. The organism, strain FXJ14(T), was found to have chemical and morphological properties characteristic of streptomycetes. Phylogenetic analyses based on an almost complete 16S rRNA gene sequence of the strain and on the 120 nt variable gamma-region of the 16S rRNA molecule showed that it formed a distinct phyletic line within the range of variation encompassed by the genus Streptomyces. The sharp separation of the organism from representatives of the genus Streptomyces was strengthened by the fact that its BOX-PCR and RFLP of 16S rDNA-ITS fingerprints differed from those of over 450 recognized Streptomyces species. The isolate also had a profile of phenotypic properties that readily distinguished it from the genotypically close type strains. It is evident from the combination of genotypic and phenotypic data that strain FXJ14(T) (=AS 4.1858(T)=JCM 12278(T)=LMG 22082(T)) should be classified as the type strain of a novel species of the genus Streptomyces, for which the name Streptomyces glauciniger sp. nov. is proposed.

Bacterial Typing Techniques↗

PubMed2004

Streptomycin as a selective agent to facilitate recovery and isolation of introduced and indigenous Sphingomonas from environmental samples.

Sphingomonas is an organism of major interest for the degradation of organic contaminants in soils and other environments. A medium based on the aminoglycoside antibiotic streptomycin (Sm) was developed, which, together with the yellow pigmentation of Sphingomonas, facilitated the detection, recovery and quantification of culturable Sphingomonas from soils. All 29 previously described bacterial strains belonging to 17 different Sphingomonas species were able to grow on mineral media containing 200 microg ml(-1) streptomycin, showing that the capacity to resist high concentrations of Sm is a common characteristic within Sphingomonas. Incorporation of Sm into the mineral medium led to a significant reduction in the background microbial population and a concomitant 100 times more sensitive detection of Sphingomonas inoculated in non-sterile soil matrices. The Sm-containing medium was used to examine a variety of hydrocarbon-contaminated soils for the presence and biodiversity of Sphingomonas. Incorporation of Sm in the medium led to a significant increase in the number of yellow-pigmented colonies. Comparison of contaminated and non-contaminated soils derived from the same site revealed colonization by culturable yellow-pigmented Sm-resistant bacteria of the polluted location solely. Both yellow and non-yellow-pigmented colonies were purified from plates containing glucose and Sm, and BOX-polymerase chain reaction (PCR) was used to sort out clonally related strains. Representative strains from the major BOX-PCR clusters were identified using FAME and partial 16S rRNA gene sequencing. Forty-eight of 58 Sm-resistant isolates were identified as Sphingomonas sp. Streptomycin-resistant Sphingomonas isolates generated BOX-PCR diversity patterns that were site dependent and represented different species mainly belonging to Sphingomonas subgroups containing species formerly designated as Sphingopyxis and Sphingobium. The ability to degrade phenanthrene was only found in a minority of the Sphingomonas isolates, which all originated from soils containing high phenanthrene concentrations.

Anti-Bacterial Agents↗

PubMed2004

Biodiversity of exopolysaccharides produced by Streptococcus thermophilus strains is reflected in their production and their molecular and functional characteristics.

Twenty-six lactic acid bacterium strains isolated from European dairy products were identified as Streptococcus thermophilus and characterized by bacterial growth and exopolysaccharide (EPS)-producing capacity in milk and enriched milk medium. In addition, the acidification rates of the different strains were compared with their milk clotting behaviors. The majority of the strains grew better when yeast extract and peptone were added to the milk medium, although the presence of interfering glucomannans was shown, making this medium unsuitable for EPS screening. EPS production was found to be strain dependent, with the majority of the strains producing between 20 and 100 mg of polymer dry mass per liter of fermented milk medium. Furthermore, no straightforward relationship between the apparent viscosity and EPS production could be detected in fermented milk medium. An analysis of the molecular masses of the isolated EPS by gel permeation chromatography revealed a large variety, ranging from 10 to >2,000 kDa. A distinction could be made between high-molecular-mass EPS (>1,000 kDa) and low-molecular-mass EPS (<1,000 kDa). Based on the molecular size of the EPS, three groups of EPS-producing strains were distinguished. Monomer analysis of the EPS by high-performance anion-exchange chromatography with amperometric detection was demonstrated to be a fast and simple method. All of the EPS from the S. thermophilus strains tested were classified into six groups according to their monomer compositions. Apart from galactose and glucose, other monomers, such as (N-acetyl)galactosamine, (N-acetyl)glucosamine, and rhamnose, were also found as repeating unit constituents. Three strains were found to produce EPS containing (N-acetyl)glucosamine, which to our knowledge was never found before in an EPS from S. thermophilus. Furthermore, within each group, differences in monomer ratios were observed, indicating possible novel EPS structures. Finally, large differences between the consistencies of EPS solutions from five different strains were assigned to differences in their molecular masses and structures.

Animals↗

PubMed2003

Six cases of Lactobacillus bacteraemia: identification of organisms and antibiotic susceptibility and therapy.

Six cases of bacteraemia in hospitalized patients, 5 with a depressed immune status, were caused by lactobacilli. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole-cell proteins and API 50 CH carbohydrate patterns assigned the causative agents to the species Lactobacillus rhamnosus, Lactobacillus curvatus, Lactobacillus delbrueckii subsp. lactis and Lactobacillus paracasei subsp. paracasei.

Adult↗

PubMed2003

Lactobacillus ingluviei sp. nov., isolated from the intestinal tract of pigeons.

Lactic acid bacteria were isolated from the crop and intestines of pigeons. One group of strains, showing similar genomic patterns after screening with tRNA intergenic spacer PCR, could not be identified to the species level. Sequencing of the 16S rRNA gene of one representative strain revealed about 96% similarity to sequences from Lactobacillus fermentum and Lactobacillus mucosae. Determination of the DNA base composition, DNA-DNA hybridization experiments, SDS-PAGE of whole-cell proteins and biochemical testing confirmed that the seven strains studied constitute a single novel Lactobacillus species, for which the name Lactobacillus ingluviei sp. nov. is proposed. The type strain is strain KR3T (=LMG 20380T =CCUG 45722T).

Animals↗

PubMed2003

Chryseobacterium joostei sp. nov., isolated from the dairy environment.

Among a large collection of South African dairy isolates, a novel Chryseobacterium taxon (DNA group 3) was previously delineated by a polyphasic taxonomic study (Hugo et al., Syst Appl Microbiol 22, 586-595, 1999). In the present paper, this taxon is further characterized using 16S rDNA sequencing, fatty acid methyl ester analysis and a comparative phenotypic analysis, resulting in the proposal of a novel species, Chryseobacterium joostei sp. nov. (type strain Ix 5a(T) = LMG 18212(T) = CCUG 46665(T)).

Animals↗

PubMed2003

Emended description of Streptococcus ferus isolated from pigs and rats.

Streptococcus ferus is a mutans-like streptococcus originally isolated from wild rats fed with sugar cane. Taxonomically, this species has not been studied extensively. Ten Gram-positive coccal strains, isolated from the tonsils and nasal conchae of piglets, were identified as S. ferus by 16S rDNA sequencing, tRNA-intergenic spacer length polymorphism analysis (tDNA-PCR), whole-cell protein profiling using SDS-PAGE, G+C content determination and extensive biochemical testing. In all these tests, the type strain of S. ferus (LMG 16520T), from a rat, was included. The results of the tests are described and an emended species description is presented.

Animals↗

PubMed2003

Paracoccus zeaxanthinifaciens sp. nov., a zeaxanthin-producing bacterium.

A comprehensive taxonomic re-evaluation was performed on the marine, zeaxanthin-producing bacterium formerly classified as [Favobacterium] sp. strain R-1 512 (ATCC 21588). This strain, together with two other previously described marine isolates, [Flavobacterium] strain R-1506 and Paracoccus sp. strain MBIC 3966, were found to comprise a new species of the genus Paracoccus. The name Paracoccus zeaxanthinifaciens sp. nov. is proposed, with ATCC 21588T (= R-1512T =LMG 21293T) designated as the type strain.

Base Composition↗

PubMed2003

Kerstersia gyiorum gen. nov., sp. nov., a novel Alcaligenes faecalis-like organism isolated from human clinical samples, and reclassification of Alcaligenes denitrificans Rüger and Tan 1983 as Achromobacter denitrificans comb. nov.

A polyphasic taxonomic study was performed on nine isolates recovered from various human clinical samples. Phenotypically, these isolates resembled Alcaligenes faecalis. Whole-cell protein analysis distinguished two different species, and this was confirmed by DNA-DNA hybridizations. Cellular fatty acid analysis and 16S rDNA sequence analysis indicated that these isolates were related to the genera Alcaligenes, Bordetella, Achromobacter and Pigmentiphaga and belonged to the family Alcaligenaceae. On the basis of the results of this study, the organisms were classified in a novel genus, Kerstersia gen. nov. This genus comprises one species, Kerstersia gyiorum sp. nov. (type strain LMG 5906(T)=API 184-2-84(T)=CCUG 47000(T)), and several unnamed isolates. The DNA G+C content of members of the genus Kerstersia is between 61.5 and 62.9 mol%. On the basis of previously published DNA-DNA hybridization results and data from chemotaxonomic studies, it is proposed that Alcaligenes denitrificans Rüger and Tan 1983 be reclassified as Achromobacter denitrificans comb. nov.

Achromobacter↗

PubMed2003

Macrococcus brunensis sp. nov., Macrococcus hajekii sp. nov. and Macrococcus lamae sp. nov., from the skin of llamas.

Eight strains of Gram-positive, catalase- and oxidase-positive cocci were isolated from the skin of llamas (Lama glama L.) and characterized using a polyphasic approach. These strains were assigned to the genus Macrococcus on the basis of their phenotypic properties (resistance to bacitracin and sensitivity to furazolidone) and DNA base content (40-42 mol% G+C). Phylogenetic analysis based on 16S rDNA confirmed that the strains are members of the genus MACROCOCCUS: They differed from all hitherto described macrococcal species in their production of phosphatase and reduction of nitrate (most strains) and the inability to produce acid from glycerol or to grow in 7.5 % NaCl. Ribotyping (EcoRI), macrorestriction analysis (XbaI) and fatty acid methyl ester analysis divided the strains from llamas into three stable clusters. Moreover, ribotyping differentiated the strains analysed not only from previously described macrococcal species but also from oxidase-positive staphylococci. DNA-DNA hybridization confirmed that the three clusters represent separate genomic groups (similarity values<54 %). All the results showed that the strains represent three novel species, for which the names Macrococcus hajekii sp. nov. (type strain CCM 4809(T)=LMG 21711(T)), Macrococcus brunensis sp. nov. (type strain CCM 4811(T)=LMG 21712(T)) and Macrococcus lamae sp. nov. (type strain CCM 4815(T)=LMG 21713(T)) are proposed.

Animals↗

PubMed2003

Achromobacter insolitus sp. nov. and Achromobacter spanius sp. nov., from human clinical samples.

A polyphasic taxonomic study (employing whole-cell protein and fatty acid analyses, 16S rDNA sequencing, DNA-DNA hybridization, determination of DNA G+C content, antibiotic susceptibility testing and extensive phenotypic characterization) was performed on 10 isolates that appeared to be related to Alcaligenes faecalis. The isolates were recovered from diverse environments that included human clinical samples. 16S rDNA sequence analysis indicated that these isolates belonged to the genus ACHROMOBACTER: Whole-cell protein analysis distinguished two groups, which were confirmed by DNA-DNA hybridization. Based on the results of this study, the organisms were classified as two novel Achromobacter species, Achromobacter insolitus sp. nov. (type strain, LMG 6003(T)) and Achromobacter spanius sp. nov. (type strain, LMG 5911(T)). Achromobacter insolitus can be distinguished from Achromobacter spanius by its ability to grow on acetamide and to assimilate mesaconate and aconitate, and by its inability to assimilate diaminobutane. Various tests allow the differentiation of both novel species from other Achromobacter species, including growth on acetamide, denitrification and assimilation of D-glucose, D-xylose, mesaconate, aconitate and diaminobutane.

Achromobacter↗

PubMed2003

Effect of raw-milk cheese consumption on the enterococcal flora of human feces.

Enterococci are one of the major facultative anaerobic bacterial groups that reside in the human gastrointestinal tract. In the present study, the composition of the enterococcal fecal flora in three healthy humans was analyzed before, during, and after the daily consumption of approximately 125 g of a raw-milk Cheddar-type cheese containing 3.2 x 10(4) enterococci/g of cheese. Enterococcal counts ranged between 1.4 x 10(2) and 2.5 x 10(8) CFU/g of feces and differed from subject to subject and from week to week. The cheese contained mainly Enterococcus casseliflavus and a small population of Enterococcus faecalis. Clonal relationships were determined by pulsed-field gel electrophoresis. Before and after consumption of the cheese, samples from humans contained mainly Enterococcus faecium, with some of the clones being resident. During consumption of the cheese, one particular transient clone of E. faecalis, clone Fs2, which was present in small numbers in the cheese, largely dominated the feces. Two clones of E. casseliflavus from the cheese were also found in the feces of one of the subjects during cheese consumption. These results suggest that a clone need not be present in a food in high numbers to establish itself in the intestine.

Animals↗

PubMed2002

Burkholderia anthina sp. nov. and Burkholderia pyrrocinia, two additional Burkholderia cepacia complex bacteria, may confound results of new molecular diagnostic tools.

Nineteen Burkholderia cepacia-like isolates of human and environmental origin could not be assigned to one of the seven currently established genomovars using recently developed molecular diagnostic tools for B. cepacia complex bacteria. Various genotypic and phenotypic characteristics were examined. The results of this polyphasic study allowed classification of the 19 isolates as an eighth B. cepacia complex genomovar (Burkholderia anthina sp. nov.) and to design tools for its identification in the diagnostic laboratory. In addition, new and published data for Burkholderia pyrrocinia indicated that this soil bacterium is also a member of the B. cepacia complex. This highlights another potential source for diagnostic problems with B. cepacia-like bacteria.

Bacterial Proteins↗

PubMed2002

Identification of Lactobacillus species using tDNA-PCR.

tDNA intergenic spacer PCR (tDNA-PCR) using consensus primers complementary to the conserved edges of the tRNA genes can amplify the intergenic spacers. Separation of the PCR products with capillary electrophoresis enables discrimination between fragments differing only one basepair in length. This method was applied to a collection of 82 Lactobacillus strains belonging to 37 species in order to evaluate the discriminatory power of this technique within this genus. Twenty-one species could be distinguished to species level on the basis of a unique tDNA fingerprint pattern. The other species grouped by two (e.g. L. fermentum and L. cellobiosus) or three (L. acidophilus, L. gallinarum and L. helveticus). Inclusion of the resulting fingerprints in a numerical database containing fingerprints of numerous other Gram-positive and Gram-negative species makes the identification of unknown strains possible.

Bacterial Typing Techniques↗

PubMed2002

Streptomyces scopiformis sp. nov., a novel streptomycete with fastigiate spore chains.

A distinct actinomycete strain was isolated from rhizosphere soil of Tsuga chinensis. The isolate, designated A25T, was assigned to the genus Streptomyces on the basis of morphological and chemotaxonomic criteria and was examined by using a polyphasic approach. An almost complete 16S rDNA sequence of the isolate was determined and compared with sequences of representative streptomycetes. The 16S rDNA data not only supported classification of the strain in the genus Streptomyces, but also showed that it formed a separate phyletic line. DNA-DNA hybridization between strain A25T and closely related reference strains confirmed that strain A25T is a novel taxon of Streptomyces. It is proposed, therefore, the strain A25T (= AS 4.1331T = LMG 20251T) is classified in the genus Streptomyces as Streptomyces scopiformis sp. nov.

Base Composition↗

PubMed2002

Phylogeny of Maricaulis Abraham et al. 1999 and proposal of Maricaulis virginensis sp. nov., M. parjimensis sp. nov., M. washingtonensis sp. nov. and M. salignorans sp. nov.

Thirteen marine bacteria isolated from different locations, belonging to the genus Maricaulis, were characterized by 16S rRNA gene sequencing, DNA-DNA hybridizations and analysis of the internally transcribed 16S-23S rDNA spacer (ITS1) region, analysis of fatty acids from total lipids, mass spectrometry of polar lipids and determination of temperature and NaCl tolerances. The data obtained led to the identification of five new sulfoquinovosyl diacylglycerols, using tandem mass spectrometry, and the fragmentation patterns of the individual compounds. Four novel species were identified and described as Maricaulis virginensis sp. nov. (type strain VKM B-1 5139T)), Maricaulis parjimensis sp. nov. (type strain MCS 25(T)), Maricaulis washingtonensis sp. nov. (type strain MCS 6(T)) and Maricaulis salignorans sp. nov. (type strain MCS 18(T)). They differ in their temperature and salt tolerances and can be differentiated by their polar lipids and fatty acid patterns, as well as their ITS1 and 16S rRNA gene sequences.

Alphaproteobacteria↗

PubMed2002

The biodiversity of lactic acid bacteria in Greek traditional wheat sourdoughs is reflected in both composition and metabolite formation.

Lactic acid bacteria (LAB) were isolated from Greek traditional wheat sourdoughs manufactured without the addition of baker's yeast. Application of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of total cell protein, randomly amplified polymorphic DNA-PCR, DNA-DNA hybridization, and 16S ribosomal DNA sequence analysis, in combination with physiological traits such as fructose fermentation and mannitol production, allowed us to classify the isolated bacteria into the species Lactobacillus sanfranciscensis, Lactobacillus brevis, Lactobacillus paralimentarius, and Weissella cibaria. This consortium seems to be unique for the Greek traditional wheat sourdoughs studied. Strains of the species W. cibaria have not been isolated from sourdoughs previously. No Lactobacillus pontis or Lactobacillus panis strains were found. An L. brevis-like isolate (ACA-DC 3411 t1) could not be identified properly and might be a new sourdough LAB species. In addition, fermentation capabilities associated with the LAB detected have been studied. During laboratory fermentations, all heterofermentative sourdough LAB strains produced lactic acid, acetic acid, and ethanol. Mannitol was produced from fructose that served as an additional electron acceptor. In addition to glucose, almost all of the LAB isolates fermented maltose, while fructose as the sole carbohydrate source was fermented by all sourdough LAB tested except L. sanfranciscensis. Two of the L. paralimentarius isolates tested did not ferment maltose; all strains were homofermentative. In the presence of both maltose and fructose in the medium, induction of hexokinase activity occurred in all sourdough LAB species mentioned above, explaining why no glucose accumulation was found extracellularly. No maltose phosphorylase activity was found either. These data produced a variable fermentation coefficient and a unique sourdough metabolite composition.

Bacterial Proteins↗

PubMed2002

Intraspecies genomic groups in Enterococcus faecium and their correlation with origin and pathogenicity.

Seventy-eight Enterococcus faecium strains from various sources were characterized by random amplified polymorphic DNA (RAPD)-PCR, amplified fragment length polymorphism (AFLP), and pulsed-field gel electrophoresis (PFGE) analysis of SmaI restriction patterns. Two main genomic groups (I and II) were obtained in both RAPD-PCR and AFLP analyses. DNA-DNA hybridization values between representative strains of both groups demonstrated a mean DNA-DNA reassociation level of 71%. PFGE analysis revealed high genetic strain diversity within the two genomic groups. Only group I contained strains originating from human clinical samples or strains that were vancomycin-resistant or beta-hemolytic. No differentiating phenotypic features between groups I and II were found using the rapid ID 32 STREP system. The two groups could be further subdivided into, respectively, four and three subclusters in both RAPD-PCR and AFLP analyses, and a high correlation was seen between the subclusters generated by these two methods. Subclusters of group I were to some extent correlated with origin, pathogenicity, and bacteriocinogeny of the strains. Host specificity of E. faecium strains was not confirmed.

Animals↗