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M D Collins

Publications and source records attributed to M D Collins.

At least 217 records · Page 12Linked to original sources
PubMed1993

Nucleotide sequence of the gene coding for Clostridium botulinum (Clostridium argentinense) type G neurotoxin: genealogical comparison with other clostridial neurotoxins.

The neurotoxin gene from Clostridium botulinum type G was cloned as a series of overlapping DNA fragments generated using polymerase chain reaction (PCR) technology and primers designed to conserved regions of published botulinal toxin (BoNT) sequences. The 5'-end of the gene was obtained using a primer based on a conserved region of the nontoxic-nonhaemagglutinin gene lying upstream of the toxin gene. Translation of the nucleotide sequence derived from the cloned PCR fragments demonstrated that the gene encodes a protein of 1297 amino acid residues (rmm 149, 147). Comparative alignment of the determined BoNT/G sequence with those of other clostridial neurotoxins revealed highest sequence relatedness (approx. 58% amino acid identity) with BoNT/B of proteolytic and non-proteolytic C. botulinum. Tetanus toxin (TeTx) and other BoNT types revealed lower levels of relatedness with BoNT/G (approximate range 35-42% amino acid identity).

Amino Acid Sequence↗
PubMed1993

Towards a phylogeny of the clostridia based on 16S rRNA sequences.

The 16S rRNA sequences of 17 species of the genus Clostridium were determined by direct sequencing of their PCR amplified genes. The sequences were aligned with those from other known clostridial species and representative low G + C Gram-positive relatives, and a phylogenetic tree was constructed. It was evident from the comparative sequence analysis that the genus Clostridium as presently constituted is phylogenetically extremely heterogeneous. This study corroborates and extends earlier findings in showing that many non-sporeforming bacteria are phylogenetically closely intermixed with Clostridium species. The taxonomic implications of the phylogenetic findings are discussed.

Clostridium↗
PubMed1993

Nucleotide sequence of the gene coding for Clostridium barati type F neurotoxin: comparison with other clostridial neurotoxins.

The neurotoxin gene from Clostridium barati ATCC43756 was cloned as a series of overlapping polymerase chain reaction (PCR) generated fragments using primers designed to conserve toxin sequences previously published. The toxin gene has an open reading frame (ORF) of 1268 amino acids giving a calculated molecular mass of 141,049 Da. The sequence identity between the C. barati ATCC43756 and non-proteolytic C. botulinum 202F neurotoxins is 64.2% for the light chain and 73.6% for the heavy chain. This is much lower than reported identities for the type E neurotoxins from C. botulinum and C. butyricum (96% identity between light chains and 98.8% between the heavy chains). Previously identified conserved regions in other botulinal neurotoxins were also conserved in that of C. barati. An ORF upstream of the toxin coding region was revealed. This shows strong homology to the 3' end of the gene coding for the nontoxic-nonhemagglutinin (NTNH) component of the progenitor toxin from C. botulinum type C neurotoxin.

Amino Acid Sequence↗
PubMed1993

Genetic interrelationships of saccharolytic Clostridium botulinum types B, E and F and related clostridia as revealed by small-subunit rRNA gene sequences.

The phylogenetic interrelationships of saccharolytic C. botulinum types B, E and F together with eleven other saccharolytic clostridia were examined by 16S rRNA gene sequencing. Comparative analysis of the sequence data revealed that the saccharolytic C. botulinum types B, E and F were highly related and represent a single genetic group. Strains of C. barati and C. butyricum that produce botulinal neurotoxin revealed almost 100% 16S rRNA sequence identity with their respective non-toxigenic counterparts and were phylogenetically distinct from saccharolytic C. botulinum (types B, E and F). Proteolytic C. botulinum type F was shown to be phylogenetically remote from the saccharolytic C. botulinum group. The implications of the sequence data for the taxonomy of the C. botulinum complex are discussed.

Base Sequence↗
PubMed1993

Molecular characterization of DNA encoding 23S rRNA and 16S-23S rRNA intergenic spacer regions of Aeromonas hydrophila.

Amplification of the gene encoding 23S rRNA of Aeromonas hydrophila by polymerase chain reaction, with primers complementary to conserved regions of 16S and the 3'-end of 23S rRNA genes, resulted in a DNA fragment of approximately 3 kb. This fragment was cloned in Escherichia coli, and its nucleotide sequence determined. The region encoding 23S rRNA shows high homology with the published sequences of 23S rRNA from other members of the gamma division of Proteobacteria. The sequence of the intergenic spacer region, between the 16S and 23S rRNA genes, was determined in five clones. Three types of spacer were identified: two clones were identical and encoded tRNA(Ile) and tRNA(Ala) while the remaining three clones contained tRNA(Glu), only two had the same spacer sequences. This variation in sequence indicates that the different clones may be derived from different ribosomal RNA operons.

Aeromonas hydrophila↗
PubMed1993

Sequence of the gene coding for the neurotoxin of Clostridium botulinum type A associated with infant botulism: comparison with other clostridial neurotoxins.

The neurotoxin gene from a strain of Clostridium botulinum type A causing infant botulism was cloned as a series of overlapping polymerase chain reaction (PCR) fragments generated using primers designed to conserved regions of published botulinal toxin (BoNT) sequences. Translation of the nucleotide sequence derived from cloned PCR fragments demonstrated that the toxin gene encodes a protein of 1,296 amino acid residues. Comparative alignment of the derived infant BoNT/A sequence with those of other published neurotoxins revealed highest sequence relatedness with BoNT/A of classical food-borne botulism. The sequence identity between infant and classical BoNT/A was 94.9% for the light chain (corresponding to 23 amino acid changes) and 87.1% for the heavy chain (corresponding to 109 amino acid changes).

Bacterial Proteins↗
PubMed1993

Phylogenetic analysis of rhizobia and agrobacteria based on 16S rRNA gene sequences.

The phylogenetic relationships of members of the genera Rhizobium, Agrobacterium, Bradyrhizobium, and Azorhizobium were studied by direct sequencing of their amplified 16S rRNA genes. Comparative analysis of the sequence data confirmed that the genera Bradyrhizobium and Azorhizobium belong to distinct phylogenetic lineages. The genera Rhizobium and Agrobacterium were found to be phylogenetically heterogeneous, and several subgroupings in which Rhizobium and Agrobacterium species were intermixed were evident. The present findings show that the genus and species definitions of these organisms are in need of revision. Different possibilities for this are discussed in the light of sequencing data.

Base Sequence↗
PubMed1993

Phylogenetic analysis of some Aerococcus-like organisms from clinical sources: description of Helcococcus kunzii gen. nov., sp. nov.

16S rRNA gene sequencing studies were performed on some unusual gram-positive catalase-negative cocci of unknown taxonomic position isolated from human clinical sources. Comparative analysis of the sequence data demonstrated that the clinical isolates represent a hitherto-unknown line of descent within the low-G+C-content gram-positive bacteria. On the basis of the phylogenetic findings and the phenotypic distinctiveness of the organisms, it is proposed that they be classified in a new genus, Helcococcus, as Helcococcus kunzii sp. nov. The type strain of H. kunzii is NCFB 2900.

Bacterial Typing Techniques↗
PubMed1993

Molecular taxonomic studies of Actinomyces-like bacteria isolated from purulent lesions in pigs and description of Actinomyces hyovaginalis sp. nov.

The 16S rRNA gene sequence of some Actinomyces-like bacteria isolated from purulent lesions in pigs was determined. A comparative analysis of the rRNA sequence data revealed that the bacteria are members of the genus Actinomyces, but are phylogenetically distinct from Actinomyces suis. On the basis of our findings and the results of previous phenotypic studies it is formally proposed that the bacteria from pigs should be designated a new species, Actinomyces hyovaginalis.

Actinomyces↗
PubMed1993

Aeromonas enteropelogenes and Aeromonas ichthiosmia are identical to Aeromonas trota and Aeromonas veronii, respectively, as revealed by small-subunit rRNA sequence analysis.

The 16S rRNA gene sequences of the type strains of Aeromonas enteropelogenes and Aeromonas ichthiosmia were determined by polymerase chain reaction direct sequencing in order to clarify their interrelationships with other aeromonad species. On the basis of 16S rRNA gene sequence analysis, A. enteropelogenes and A. ichthiosmia were found to be identical to Aeromonas trota and Aeromonas veronii, respectively.

Aeromonas↗
PubMed1993

Taxonomic studies on some leuconostoc-like organisms from fermented sausages: description of a new genus Weissella for the Leuconostoc paramesenteroides group of species.

Taxonomic studies were performed on some unknown Leuconostoc-like organisms from fermented Greek sausage. Comparative 16S rRNA sequence analysis showed the unidentified organisms represent a new line within the Leuconostoc paramesenteroides group of species. On the basis of the results of this and earlier phylogenetic investigations, it is proposed that Leuconostoc paramesenteroides and related species be reclassified in a new genus Weissella. In addition a new species, Weissella hellenica, is proposed for the isolates from fermented sausage.

Base Sequence↗
PubMed1993

Phenotypic and phylogenetic characterization of some Gemella-like organisms from human infections: description of Dolosigranulum pigrum gen. nov., sp. nov.

A phylogenetic analysis was performed on two previously uncharacterized Gram-positive, catalase-negative bacteria from clinical sources. 16S rRNA sequencing studies revealed the isolates represent a new line of descent within the lactic acid group of bacteria. On the basis of the phylogenetic findings and phenotypic distinctiveness of the organisms, it is proposed that they be classified in a new genus Dolosigranulum, as Dolosigranulum pigrum sp. nov. The type strain of Dolosigranulum pigrum is NCFB 2975.

Base Sequence↗
PubMed1993

Use of the polymerase chain reaction and 16S rRNA sequences for the rapid detection of Brochothrix spp. in foods.

Oligonucleotide primers were designed against rRNA sequences to give a DNA-based PCR assay for the rapid identification/detection of Brochothrix spp. The PCR products could be confirmed by hybridization to an internal oligonucleotide probe. The method successfully and sensitively detected/identified these organisms in pure cultures but was of limited value as a detection method because the detection sensitivity, in relation to conventional plate counts, varied and the assay sensitivity was reduced in the presence of staphylococci. Furthermore, sensitivity was also lost when the assay was applied directly to meat samples. However, a separation step using a lectin (from Agaricus bisporus) immobilized on magnetic beads prior to the PCR assay, allowed the direct detection of low numbers (> 10(2) cfu g-1) of Brochothrix in meat samples within a working day.

Animals↗
PubMed1993

A Staphylococcus aureus-specific oligonucleotide probe derived from 16S rRNA gene sequences.

Genes encoding 16S rRNA were sequenced from 16 species of Staphylococcus. Sequence analysis highlighted a potential Staph. aureus-specific region and a complementary oligonucleotide probe was synthesized and its specificity tested. Northern blotting indicated molecular specificity, and dot blots to RNA from Staph. aureus, Staph. capitis, Staph. caprae, Staph. carnosus, Staph. caseolyticus, Staph. cohnii, Staph. epidermidis, Staph. gallinarum, Staph. haemolyticus, Staph. hominis, Staph. hyicus, Staph. saprophyticus, Staph. sciuri, Staph. simulans, Staph. warneri and Staph. xylosus indicated species-specificity.

Base Composition↗
PubMed1993

Development and use of species-specific oligonucleotide probes for differentiation of Streptococcus uberis and Streptococcus parauberis.

Oligonucleotide probes specific for 16S rRNA and capable of differentiating Streptococcus uberis and S. parauberis from each other and other esculin-hydrolyzing streptococci were developed. Use of a mini-RNA extraction technique for gram-positive cocci associated with bovine mastitis has allowed the probes to be used for identification of esculin-hydrolyzing streptococci from two dairy herds at the Institute for Animal Health, Compton, United Kingdom. One hundred seventy-nine of 206 isolates were identified as S. uberis, 3 were identified as S. parauberis, and 24 were not identified. Isolates not identified by the probes were tested biochemically and found to be mainly Enterococcus faecium, E. faecalis, or S. bovis.

Animals↗