Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS), a culture based alternative for microbial diversity studies, is an attractive tool to dereplicate large numbers of isolates to a smaller set of representatives for downstream characterization. In the present study, MALDI-TOF MS, combined with a database of reference spectra compiled in previous studies, was applied to identify 88 non-starter lactic acid bacteria (NSLAB) isolated from 18 samples of four different artisanal cheeses produced in the Island of Naxos, Greece, from raw sheep and goat milk without the addition of starters. Eighty-four isolates (95.
View Article and Find Full Text PDFComparative analysis of partial , , and gene sequences of 84 reference strains and field isolates revealed several clusters that included no taxonomic reference strains. The , , and phylogenetic trees were used to select 27 strains for whole-genome sequence analysis and for a comparative genomics study that also included 41 publicly available genome sequences. The phylogenomic analyses included a Genome BLAST Distance Phylogeny approach to calculate pairwise digital DNA-DNA hybridization values and their confidence intervals, average nucleotide identity analyses using the OrthoANIu algorithm, and a whole-genome phylogeny reconstruction based on 107 single-copy core genes using bcgTree.
View Article and Find Full Text PDFPartial gyrB gene sequence analysis of 17 isolates from human and environmental sources revealed 13 clusters of strains and identified them as Burkholderia glathei clade (BGC) bacteria. The taxonomic status of these clusters was examined by whole-genome sequence analysis, determination of the G+C content, whole-cell fatty acid analysis and biochemical characterization. The whole-genome sequence-based phylogeny was assessed using the Genome Blast Distance Phylogeny (GBDP) method and an extended multilocus sequence analysis (MLSA) approach.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
April 2016
Isolates LMG 28357T (=R-53146T) and LMG 28623 were obtained from gut samples of Bombus lapidarius bumblebees caught in Ghent, Belgium. They had identical 16S rRNA gene sequences which were 95.7 % identical to that of Apibacter adventoris wkB301T, a member of the family Flavobacteriaceae.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
November 2015
An aerobic, Gram-stain-negative rod, designated strain A2P5T, was isolated from the Douro river, in Porto, Portugal. Cells were catalase- and oxidase-positive. Growth occurred at 15-30 °C, at pH 6-8 and in the presence of 1 % (w/v) NaCl.
View Article and Find Full Text PDFBMC Pharmacol Toxicol
December 2013
Background: The gut microbiota is critical for intestinal homeostasis. Recent studies have revealed the links between different types of dysbiosis and diseases inside and outside the intestine. Environmental exposure to pollutants (such as heavy metals) can also impair various physiological functions for good health.
View Article and Find Full Text PDFAnalysis of partial gyrB gene sequences revealed six taxa in a group of 17 Burkholderia glathei-like isolates which were further examined by (GTG)5-PCR fingerprinting, 16S rRNA gene sequence analysis, DNA-DNA hybridizations, determination of the DNA G+C content, whole-cell fatty acid analysis and an analysis of cell and colony morphology and more than 180 biochemical characteristics. The results demonstrated that one taxon consisting of three human clinical isolates represented Burkholderia zhejiangensis, a recently described methyl-parathion-degrading bacterium isolated from a wastewater-treatment system in China. The remaining taxa represented five novel species isolated from soil or rhizosphere soil samples, and could be distinguished by both genotypic and phenotypic characteristics.
View Article and Find Full Text PDFAn important part of the daily nourishment in Vietnam constitutes of fermented vegetables. Bacteria and especially lactic acid bacteria play a central role in the production of many fermented vegetables. The current study was conducted to investigate the diversity of native lactic acid bacteria (LAB) populations in 'dua muoi' (mustard and beet fermentation) and 'ca muoi' (eggplant fermentation), three types of popular traditional fermented vegetables of Vietnamese origin.
View Article and Find Full Text PDFEight coagulase-negative, novobiocin-susceptible staphylococcal strains were isolated from human clinical specimens at two different Belgian medical facilities. All strains were non-motile, Gram-stain-positive, catalase-positive cocci. DNA G+C content, peptidoglycan type, menaquinone pattern, the presence of teichoic acid and cellular fatty acid composition were in agreement with the characteristics of species of the genus Staphylococcus.
View Article and Find Full Text PDFThe phenotypic and genotypic characteristics of fourteen human clinical Achromobacter strains representing four genogroups which were delineated by sequence analysis of nusA, eno, rpoB, gltB, lepA, nuoL and nrdA loci, demonstrated that they represent four novel Achromobacter species. The present study also characterized and provided two additional reference strains for Achromobacter ruhlandii and Achromobacter marplatensis, species for which, thus far, only single strains are publicly available, and further validated the use of 2.1% concatenated nusA, eno, rpoB, gltB, lepA, nuoL and nrdA sequence divergence as a threshold value for species delineation in this genus.
View Article and Find Full Text PDFA species diversity study of lactic acid bacteria occurring in traditional Vietnamese nem chua yielded an isolate, LMG 26767(T), that could not be assigned to a species with a validly published name. The isolate was initially investigated by 16S rRNA gene sequence analysis, which revealed that it belonged to the genus Lactobacillus, with Lactobacillus manihotivorans and Lactobacillus camelliae as the closest relatives (98.9 % and 96.
View Article and Find Full Text PDFForty-eight Burkholderia isolates from different land use systems in the Amazon region were compared to type strains of Burkholderia species for phenotypic and functional characteristics that can be used to promote plant growth. Most of these isolates (n=46) were obtained by using siratro (Macroptilium atropurpureum - 44) and common bean (Phaseolus vulgaris - 2) as the trap plant species; two isolates were obtained from nodules collected in the field from Indigofera suffruticosa and Pithecellobium sp. The evaluated characteristics were the following: colony characterisation on "79" medium, assimilation of different carbon sources, enzymatic activities, solubilisation of phosphates, nitrogenase activity and antifungal activity against Fusarium oxysporium f.
View Article and Find Full Text PDFThe aim of the present study was to identify a collection of 35 Cupriavidus isolates at the species level and to examine their capacity to nodulate and fix N(2). These isolates were previously obtained from the root nodules of two promiscuous trap species, Phaseolus vulgaris and Leucaena leucocephala, inoculated with soil samples collected near Sesbania virgata plants growing in Minas Gerais (Brazil) pastures. Phenotypic and genotypic methods applied for this study were SDS-PAGE of whole-cell proteins, and 16S rRNA and gyrB gene sequencing.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
September 2012
Analysis of gyrB gene sequences, (GTG)(5)-primed PCR fingerprinting and biochemical characteristics determined in the Biolog GEN III microtest system were used to differentiate an unnamed Kerstersia species from Kerstersia gyiorum, the type and only named species in this genus. The inability to oxidize D-galacturonic and D-glucuronic acids and the ability to oxidize D-serine, along with gyrB gene sequence analysis and (GTG)(5)-PCR fingerprints, readily differentiated the unnamed taxon from the type species. Therefore, we propose to formally classify this unnamed taxon as Kerstersia similis sp.
View Article and Find Full Text PDFTwo bacterial strains (SC-089(T) and SC-092(T)) isolated from sewage sludge compost were characterized by using a polyphasic approach. The isolates were Gram-negative short rods, catalase- and oxidase-positive, and showed good growth at 30 °C, at pH 7 and with 1 % (w/v) NaCl. Ubiquinone 8 was the major respiratory quinone, and phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol were amongst the major polar lipids.
View Article and Find Full Text PDFFour butyrate-producing isolates were obtained from the caecal content of a 4-week-old broiler chicken. The 16S rRNA gene sequences were determined and confirmed the close relatedness of the four isolates, which suggested that they were derived from a single bacterial clone. Phylogenetic analysis based on 16S rRNA gene sequences showed that its closest relatives were members of cluster XIVa of the Clostridium subphylum of Gram-positive bacteria and that the closest related type strain was Anaerostipes caccae L1-92(T) (94.
View Article and Find Full Text PDFA polyphasic study was undertaken to clarify the taxonomic position of Campylobacter lari-like strains isolated from shellfish and humans. The diversity within the strain collection was initially screened by means of fluorescent amplified fragment length polymorphism analysis and whole-cell protein electrophoresis, revealing the existence of two clusters distinct from C. lari and other Campylobacter species.
View Article and Find Full Text PDFThe aim of the present study was to re-examine the taxonomic position and structure of taxon K (also known as group K) within the Burkholderia cepacia complex (Bcc). For this purpose, a representative set of strains was examined by a traditional polyphasic taxonomic approach, by multilocus sequence typing (MLST) analysis and by analysis of available whole-genome sequences. Analysis of the recA gene sequence revealed three different lineages, designated recA-I, recA-II and recA-III.
View Article and Find Full Text PDFThe taxonomic position of five recA gene clusters of Burkholderia cepacia complex (Bcc) isolates was determined using a polyphasic taxonomic approach. The levels of 16S rRNA and recA gene sequence similarity, multilocus sequence typing (MLST) data and the intermediate DNA-DNA binding values demonstrated that these five clusters represented five novel species within the Bcc. Biochemical identification of these species is difficult, as is the case for most Bcc species.
View Article and Find Full Text PDFThe main aim of this study was to evaluate the specificity of three commonly used 16S rRNA gene-based polymerase chain reaction (PCR) primer sets for bacterial community analysis of samples contaminated with eukaryotic DNA. The specificity of primer sets targeting the V3, V3-V5, and V6-V8 hypervariable regions of the 16S rRNA gene was investigated in silico and by community fingerprinting of human and fish intestinal samples. Both in silico and PCR-based analysis revealed cross-reactivity of the V3 and V3-V5 primers with the 18S rRNA gene of human and sturgeon.
View Article and Find Full Text PDFThe sensitivity and specificity of 7 PCR assays described for the identification of Campylobacter jejuni and Campylobacter coli were examined using alkaline cell lysates from a collection of 100 well characterized reference strains of C. jejuni, C. coli, Campylobacter lari and related Campylobacter, Helicobacter and Arcobacter species.
View Article and Find Full Text PDFA Gram-negative, rod-shaped, aerobic bacterium, designated strain RP007(T), was isolated from a polycyclic aromatic hydrocarbon-contaminated soil in New Zealand. Two additional strains were recovered from a compost heap in Belgium (LMG 18808) and from the rhizosphere of maize in the Netherlands (LMG 24204). The three strains had virtually identical 16S rRNA gene sequences and whole-cell protein profiles, and they were identified as members of the genus Burkholderia, with Burkholderia phenazinium as their closest relative.
View Article and Find Full Text PDFA polyphasic taxonomic study including DNA-DNA reassociation experiments and an extensive biochemical characterization was performed on 14 Burkholderia isolates from moss gametophytes of nutrient-poor plant communities on the southern Baltic Sea coast in northern Germany. The strains were classified within two novel species, for which the names Burkholderia bryophila sp. nov.
View Article and Find Full Text PDFDiet is a major factor in maintaining a healthy human gastrointestinal tract, and this has triggered the development of functional foods containing a probiotic and/or prebiotic component intended to improve the host's health via modulation of the intestinal microbiota. In this study, a long-term placebo-controlled crossover feeding study in which each subject received several treatments was performed to monitor the effect of a prebiotic substrate (i.e.
View Article and Find Full Text PDFThe large intestine of dogs contains a complex microbial ecosystem with predominance of streptococci, bifidobacteria, lactobacilli, Bacteroides and Clostridium. Generally, this predominant microbiota in dogs is relatively stable in time but much less is known about its taxonomic composition. Moreover, almost no studies have been conducted to investigate this stability of the faecal microbial population in dogs upon prebiotic administration.
View Article and Find Full Text PDF