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Biomedical subjects

M Goodfellow

Publications and source records attributed to M Goodfellow.

At least 73 records · Page 4Linked to original sources
PubMed1994

Theoretical and practical aspects of the quantification of biodiversity among microorganisms.

The quantification of biodiversity among microorganisms has to address both theoretical and practical aspects. Species concepts are often at variance with those applied in macroorganisms, and satisfactory concepts suitable for general use in bacteria and fungi have yet to be formulated. Molecular approaches have not yet provided a universal solution to this key issue. Quantification in habitats such as soil is difficult as isolation procedures yield only a small and skewed selection of the microorganisms present. Indices of taxonomic or phylogenetic diversity have potential in the quantification of microbial diversity at a range of ranks, but the non-equivalence of ranks and representatives of the taxa detected have to be addressed. Chemical and molecular methods have immense potential in the quantification of microbial diversity in environmental samples; 16S rRNA has shown particular promise with bacteria, but as yet the fungi lack a universal probe. A greater awareness of the limitations of existing approaches and methodologies used by microbiologists is needed, but significant progress can be anticipated as new technologies are developed and become more widely adopted.

Bacteria↗
PubMed1994

Distribution of oxoacyl synthase homology sequences within Streptomyces DNA.

A genomic DNA sequence of Streptomyces strain ISP 5485 was cloned, sequenced and compared with corresponding information from nuclei acid data banks. The DNA sequence was unique, but showed homology to DNA coding for the condensing enzyme, 2-oxoacyl synthase, of the deoxyerythronolide B synthase complex (DEBS) from Saccharopolyspora erythraea NRRL 2338. A subfragment of the sequenced DNA was used to construct a gene-specific probe that formed part of the putative 2-oxoacyl synthase gene. The PCR-amplified and labelled probe was used in hybridization experiments involving 33 streptomycete strains that produced different classes of antibiotics. The probe showed widespread homology with DNA considered to be part of analogous genes within genomes of different polyketide producers. The implications of the probe homology to bacterial chromosomal DNA are discussed.

Amino Acid Sequence↗
PubMed1994

Characterization of the specific antigenicity of representatives of M. senegalense and related bacteria.

Representative strains of M. senegalense and an unusual strain, labelled M. farcinogenes (M280) were examined by thin-layer chromatography for the presence of characteristic surface glycolipids. In the case of M. farcinogenes M280 and M. senegalense M264, the glycolipids were of the alkali-labile acyltrehalose lipooligosaccharide (LOS) class of antigens, whereas M. senegalense M263 was found to contain the alkali-stable glycopeptidolipids (GPL). Through a combination of 1H-NMR, methylation analysis, FAB/MS, and other analytical techniques, the structures of these glycolipids were deduced. The LOS glycolipids were found to be similar in structure to the characteristic glucosyltrehalose-based glycolipids isolated previously from clinical isolates of M. fortuitum, but distinct from the diacyltrehaloses characteristic of the type strain of M fortuitum. The glycopeptidolipids from M. senegalense M263 were closely similar to those characterized previously from M.

Animals↗
PubMed1994

Rapid characterisation and identification of mycobacteria using fluorogenic enzyme tests.

Sixty representatives of selected Mycobacterium and Nocardia species were examined for their ability to cleave 79 fluorogenic synthetic enzyme substrates based on the fluorophores 7-amino-4-methylcoumarin and 4-methylumbelliferone. The resultant data were analysed using the simple matching coefficient and clustering achieved using the unweighted pair group method with arithmetic averages algorithm. Clusters corresponding to the validly described species Mycobacterium bovis, M. chelonae, M. chitae, M. farcinogenes, M. fortuitum, M. peregrinum, M. senegalense, M. smegmatis, Nocardia asteroides, and N. farcinica were circumscribed at or above the 83% similarity level. Fluorogenic probes prepared from 7-amino-4-methylcoumarin and 4-methylumbelliferone provide a rapid means of detecting taxonomically useful enzymes in small amounts of whole mycobacteria and nocardiae.

Clinical Enzyme Tests↗
PubMed1994

Transfer of Nocardia amarae Lechevalier and Lechevalier 1974 to the genus Gordona as Gordona amarae comb. nov.

The taxonomic status of Nocardia amarae strains was examined using chemical, microbiological and nucleic acid sequencing methods. It was evident from the results of this and previous studies that Nocardia amarae has properties that are at variance with its classification in the genus Nocardia but consistent with its transfer to the genus Gordona. It is proposed that Nocardia amarae Lechevalier and Lechevalier 1974 be transferred to the genus Gordona as Gordona amarae comb. nov.

Actinomycetales↗
PubMed1993

Rapid identification of streptomycetes by artificial neural network analysis of pyrolysis mass spectra.

An artificial neural network was trained to distinguish between three putatively novel species of Streptomyces using normalised, scaled prolysis mass spectra from three representative strains of each of the taxa, each sampled in triplicate. Once trained, the artificial neural network was challenged with spectral data from the original organisms, the 'training set', from additional members of the putative novel taxa and from over a hundred strains representing six other actinomycete genera. All of the streptomycetes were correctly identified but many of the other actinomycetes were mis-identified. A modified network topology was developed to recognise the mass spectral patterns of the non-streptomycete strains. The resultant neural network correctly identified the streptomycetes, whereas all of the remaining actinomycetes were recognised as unknown organisms. The improved artificial neural network provides a rapid, reliable and cost-effective method of identifying members of the three target streptomycete taxa.

Actinomycetales↗
PubMed1993

Artificial neural network analysis of pyrolysis mass spectrometric data in the identification of Streptomyces strains.

Sixteen representatives of three morphologically distinct groups of streptomycetes were recovered from soil using selective isolation procedures. Duplicated batches of the test strains were examined by Curie-point pyrolysis mass spectrometry and the first data set used for conventional multivariate statistical analyses and as a training set for an artificial neural network. The second set of data was used for 'operational fingerprinting' and for testing the artificial neural network. All of the test strains were correctly identified using the artificial neural network whereas only fifteen of the sixteen strains were assigned to the correct group using the conventional operational fingerprinting procedure. Artificial neural network analysis of pyrolysis mass spectrometric data provides a rapid, cost-effective and reproducible way of identifying and typing large numbers of microorganisms.

Bacterial Typing Techniques↗
PubMed1993

Identification of some clinically significant actinomycetes.

Early recognition of infections caused by actinomycetes tend to be highly dependent on at least a tentative diagnosis derived from microbiological tests, since the clinical symptoms can be difficult to interpret. Reliable identification of clinically significant actinomycetes depends upon the application of taxonomic techniques that are not yet widely used in clinical laboratories. The value of rapid enzyme, chemical and molecular fingerprinting techniques is exemplified by their application to the identification of representatives of clinically significant actinomycete taxa.

Actinomycetales Infections↗
PubMed1993

Thin-layer chromatographic analysis of glycolipids and mycolic acids from Mycobacterium farcinogenes, Mycobacterium senegalense and related taxa.

Seventy-nine representative strains of Mycobacterium farcinogenes, Mycobacterium fortuitum, Mycobacterium peregrinum and Mycobacterium senegalense were analysed by thin-layer chromatography for diagnostic glycolipid and mycolic acid patterns. On the basis of glycolipid patterns the 16 M. senegalense strains were assigned to four groups (I, II, III and IV); one strain received as M. farcinogenes had glycolipids that corresponded to those given by the M. senegalense group III strain. Representatives of M. fortuitum produced alkalilabile glycolipids whereas the M. peregrinum strains produced alkali-stable glycopeptidolipids related to those of M. senegalense group I. Members of M. senegalense groups I, III and IV and the M. farcinogenes strains gave the characteristic pattern consisting of alpha- and epoxymycolates on thin-layer chromatographic analysis of the products of alkaline hydrolysis with 5% aqueous tetrabutylammonium hydroxide. Extraction of mycolates from the same strains using acid methanolysis revealed alpha-mycolates and characteristic more polar long-chain components originating from epoxymycolates. In contrast, the M. senegalense group II strains contained an additional more polar omega-1 methoxymycolate that was detected from both acid and alkaline hydrolysates; this spot was also seen in some M. fortuitum and M. peregrinum strains. Preliminary investigations, using a combination of thin-layer chromatography and immunostaining, showed that glycopeptidolipids from M. peregrinum and M. senegalense group I strains were antigenic, a cross-reaction between members of these taxa was shown. In contrast, no reaction was detected between glycopeptidolipids extracted from M. peregrinum and M. senegalense group I strains with antisera from either M. farcinogenes or M. fortuitum.

Animals↗
PubMed1993

Suprageneric classification of thermoactinomyces vulgaris by nucleotide sequencing of 5S ribosomal RNA.

The 5S rRNA nucleotide sequence of Thermoactinomyces vulgaris was determined and compared with published sequences of representative Gram-positive bacteria. The primary and secondary structure of the sequence is of the type characteristic of Gram-positive bacteria that have DNA with a low proportion of guanine plus cytosine. It was evident from the phylogenetic trees that T. vulgaris has little in common with actinomycetes but is related to the genus Bacillus, showing a moderately high relationship with B. stearothermophilus. The taxonomic implications of these relationships are discussed and an emended description of the family Bacillaceae is given.

Bacillaceae↗
PubMed1993

A simple chemical test to distinguish mycobacteria from other mycolic-acid-containing actinomycetes.

Two hundred and fifty-two representatives of the general Corynebacterium, Gordona, Mycobacterium, Nocardia, Rhodococcus and Tsukamurella were degraded by alkaline hydrolysis and their mycolic acids extracted as methyl esters following phase-transfer-catalysed esterification. When the mycolic acid methyl esters were treated with a mixture of acetonitrile and toluene all mycobacterial mycolates formed copious white precipitates whereas all but 5 out of the 106 non-mycobacterial mycolates remained in solution. The precipitated methyl mycolates and the dried soluble mycolates were compared by pyrolysis gas chromatography and silica gel thin-layer chromatography. On pyrolysis, the precipitated methyl mycolates from mycobacteria yielded fatty acid methyl esters with 20 to 26 carbon atoms whereas those from the remaining taxa produced shorter-chain esters. Mycobacteria and Tsukamurella paurometabola gave multispot mycolic acid patterns on thin-layer chromatography of their methyl esters whereas those from the remaining strains gave single spots. Our results indicate that Rhodococcus chlorophenolicus strains contain mycolic acids atypical of mycobacteria. It can be concluded that the mycolic acid precipitation test provides a simple and reliable way of distinguishing mycobacteria from all other prokaryotes, notably from other mycolic-acid-containing taxa.

Actinomycetales↗
PubMed1992

Numerical classification and identification of Streptomyces species--a review.

Evidence is presented to show that numerical taxonomy is of proven value both for the circumscription and identification of Streptomyces species. In addition, 252 representatives of numerically defined species and species-groups of this taxon were examined for 273 unit characters and the resultant data analysed using conventional statistics. Clustering was only marginally affected by the proximity coefficients used or by test error, estimated at 3.37%. The numerical classification obtained confirmed and extended the results of previous taxometric surveys, notably by showing that the Streptomyces albidoflavus species-group encompassed taxospecies corresponding to S. albidoflavus, Streptomyces anulatus and Streptomyces halstedii. Rapid enzyme tests based upon the fluorophores, 7-amino-4-methylcoumarin and 4-methylumbelliferone, provide useful data for streptomycete systematics. It can be concluded that the genus Streptomyces is currently well circumscribed and underspeciated.

Species Specificity↗
PubMed1992

Pyrolysis mass spectrometry as a method for the classification, identification and selection of actinomycetes.

Pilot experiments were designed to determine the potential of Curie-point pyrolysis mass spectrometry (PyMS) in the classification, identification and typing of industrially significant actinomycetes, and for the detection of target and novel actinomycetes needed for pharmacological screening programmes. The results indicate that the method is of value for the separation of actinomycetes at and below the species level, in the detection and circumscription of novel actinomycetes, and for the detection of identical and duplicated strains. There is also evidence that the pyrolysis system will permit the identification of target actinomycetes directly from selective isolation plates. PyMS is one of the methods that should be used to generate polyphasic taxonomies of actinomycete genera.

Actinomycetales↗
PubMed1992

Characteristics of Streptomyces globisporus strain 0234A forming endospores in submerged cultures.

Thermosensitive submerged endospores formed by Streptomyces globisporus 0234 and its natural variant A resembled those of thermoresistant actinomycetes not only in their morphology ultrastructure, but also in the content of dipicolinic acid. The production of endospores containing this substance is unusual in Streptomyces while other features of the strain indicate relatedness to other streptomycetes. Chemotaxonomic analysis of variant A revealed the cell wall to be of chemotype I and fatty acid content typical of Streptomyces. Most characteristics of surface cultures of variant A coincided with those of the original strain 0234 and its endosporeless variant B. Both the strain 0234 and its variants A and B produced identical antibiotics and pesticidal compounds.

Anti-Bacterial Agents↗
PubMed1992

Biodiversity as a source of innovation in biotechnology.

The object of this article is to draw attention to the significance of microbial diversity as a major resource for biotechnological products and processes. The topic is approached from two complementary standpoints. First, an attempt is made to assess the extent of biodiversity, particularly microbial diversity. In this context, the application of the modern techniques of molecular biology is enabling the detection of hitherto completely unknown groups of microbes and, also, is revealing the extent of genetic diversity within microbial taxa. The case is made for the establishment of sound microbial taxonomies both on the basis of satisfying fundamental scientific needs, and for designing effective isolation strategies. The impact of an ecological approach to search and discovery of novel organisms and properties also is emphasized and illustrated. Second, the question of screening a collection of appropriate microorganisms for the desired attributes is considered. The focus here is placed on modern intelligent or targeted screening, and on the power of molecular biology to extend the range of screening options. Discussions of microbial ecology or diversity only rarely touch upon questions of gene pool conservation. The point made here is that loss of biodiversity should be as ominous for microbiologists and biotechnologists as it is to conservationists. The article concludes with thoughts on some means of conserving microbial diversity.

Biotechnology↗
PubMed1991

Polyphasic taxonomic study of the genera Gordona and Tsukamurella including the description of Tsukamurella wratislaviensis sp. nov.

Representatives of the genera Gordona and Tsukamurella together with related actinomycetes were the subject of chemotaxonomic, numerical taxonomic and DNA homology studies. In the numerical analysis the organisms were examined for 116 unit characters and the data sorted using the simple matching, Jaccard and pattern coefficients; clustering was achieved using the unweighted pair group method with arithmetic averages algorithm. The numerical groupings were not affected by the statistics used or by test error, estimated at 1.9%. The numerical taxonomic data supported the integrity of the four validly described species of Gordona but indicated that the genus Tsukamurella might encompass a species in addition to Tsukamurella paurometabola. The putative new strains had chemical, enzymic, nutritional and tolerance properties consistent with their assignment to the genus Tsukamurella and formed a DNA homology group corresponding to the one formed by the Tsukamurella paurometabola strains. It is proposed that the new taxon be assigned to the genus Tsukamurella as Tsukamurella wratislaviensis.

Actinomycetales↗
PubMed1991

Menaquinone patterns of Amycolatopsis species.

The menaquinones of representative strains of the actinomycete genus Amycolatopsis were examined by reverse phase thin-layer chromatography and mass spectrometry. Representatives of all seven validly described species contained various combinations of di-, tetra- and hexahydrogenated menaquinones with nine isoprene units as predominant isoprenologues. It seems likely that the variation in the predominant menaquinones merely reflects the stages from the growth cycle from which biomass was taken. The detection of major proportions of hydrogenated menaquinones with nine isoprene units serves to distinguish Amycolatopsis strains from most other actinomycetes, notably those belonging to related genera such as Amycolata and Pseudonocardia.

Actinomycetales↗