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Biomedical subjects

J G Collee

Publications and source records attributed to J G Collee.

At least 37 records · Page 2Linked to original sources
PubMed1982

Detection of species-specific and cross-reactive cell-surface antigens of Bacteroides species by an indirect enzyme-linked immunosorbent assay.

EDTA-released outer-membrane antigen complexes were prepared from 172 laboratory and reference strains and 43 fresh clinical or faecal isolates representing 20 species or subspecies of Bacteroides, together with 13 species of other genera. These antigens were titrated against antisera to whole, live cells of 21 species or subspecies of Bacteroidaceae in an indirect enzyme-linked immunosorbent assay (ELISA). The presence of species-specific antigens was investigated and cross reactions between species were noted. Results showed that a high proportion of the species possess species-specific antigens with little significant cross reactivity. We believe that the ELISA system described here detects antigens that represent the whole cell surface of bacteroides organisms. We have exploited the sensitivity of the system and its quantitative potential to define approaches for those wishing to use serological approaches for either the identification of Bacteroides species or for the titration of serum antibodies in patients with a possible bacteroides infection.

Antigens, Bacterial↗
PubMed1982

Current approaches to the classification, characterisation and typing of pathogenic anaerobic bacteria.

Characterisation systems based on the demonstration of soluble antigens and toxins are of much practical value but have clear taxonomic limitations. This is illustrated by reference to our work with some of the pathogenic clostridia. The definition and classification of the anaerobic cocci is a difficult and continuing challenge. Systems for the classification and characterisation of the gram-negative non-sporing anaerobic bacilli are evolving well, though there are still some very difficult areas. A selection of the most helpful tests is indicated. Biotyping systems are compared with serotyping systems; the results of serological approaches to characterisation are encouraging. The further exploration of bacteriocin typing seems to be merited. The challenge of characterisation and classification of anaerobic spirochaetes commonly involved in human infections must now be taken up.

Amino Acids↗
PubMed1980

Mechanisms of pathogenicity of anaerobic bacteria of clinical interest.

The host factors leading to anaerobic infection and the various models of anaerobic infection, namely direct effect of a single toxin, multiple toxin-aggressin-systems, enterotoxic mechanisms, endogenous infections with non-clostridial anaerobes, and synergistic infections, are reviewed. Production of carcinogens and co-carcinogens by anaerobes is also discusssed.

Anaerobiosis↗
PubMed1980

Factors contributing to loss of anaerobic bacteria in transit from the patient to the laboratory.

Care and attention to detail in the sampling, transit and submission of a specimen for anaerobic bacteriological investigation are of paramount importance. The swab is a relatively inefficient sampling device and is often abused. A transport system may help, but a full evaluation of our sampling and transport methodology is needed and this will be influenced by local circumstances.

Anaerobiosis↗
PubMed1980

Prompt and reliable culture of exacting anaerobic bacteria in anaerobic jars.

The presently recognized anaerobic bacteria of clinical interest, with the possible exception of some spirochaetes, can be cultured by conventional procedures with an anaerobic jar. Care and attention to detail in the design and operation of an anaerobic jar are essential. Anaerobic cabinets and oxygen-free gassing systems may contribute to further research and development, but the potential usefulness of a good anaerobic jar in clinical bacteriology should not be under-rated.

Anaerobiosis↗
PubMed1980

A scheme for the identification of clinical isolates of Gram-negative anaerobic bacilli by conventional bacteriological tests.

More than 1000 strains of gram-negative anaerobic bacilli, including reference strains, clinical isolates, and members of the normal flora of the mouth, lower gastro-intestinal tract and vagina of healthy human subjects, were studied by conventional bacteriological methods and by gas-liquid chromatographic analysis of metabolic products in a series of investigations. A short combined set of tests with particular discriminant value was selected, and a scheme for the identification of the species and subspecies encountered in the diagnostic bacteriological laboratory was based upon our composite results. The tests are: antibiotic-disk resistance tests with neomycin 1000 micrograms, kanamycin 1000 micrograms, penicillin 2 units and rifampicin 15 micrograms per disk; tolerance tests with sodium taurocholate, Victoria blue 4R and gentian violet; and tests for pigment production, indole production, aesculin hydrolysis and the fermentation of glucose, lactose, sucrose, rhamnose, trehalose, mannitol and xylose. Gram-negative anaerobic bacilli are divided into four groups: (1) the fragilis group with nine species, which include the five subgroups previously classified as subspecies of B. fragilis; (2) the melaninogenicus-oralis group, which includes the three saccharolytic subspecies (ss.) of B. melaninogenicus--ss. melaninogenicus, ss. intermedius and ss. levii--and four non-pigmented species; (3) the asaccharolytic group, which comprises B. asaccharolyticus (formerly B. melaninogenicus ss. asaccharolyticus), B. corrodens and other non-pigmented non-saccharolytic strains, and (4) the fusobacteria.

Anti-Bacterial Agents↗
PubMed1979

Are anaerobic pleuropulmonary infections uncommon or commonly undetected in Britain?

Despite marked and increasing awareness of the clinical significance of pathogenic anaerobes, the role of anaerobes in pleuropulmonary infections is still largely unrecognised in Britain. A considerable literature testifies that this is not so in America. The reasons for this paradox are explored. British anaerobic methodology is briefly reviewed, with special reference to the range of recognised respiratory pathogens and the anaerobes that can be cultured in simple anaerobic jars. The limitations of sampling and transport procedures are considered. Differences in approach are discussed. The technological problems of the isolation and culture of "difficult" pathogenic anaerobes have been largely solved at the laboratory level; effective approaches to sampling and transit of specimens require more positive consideration and the results might influence our choice of specific antimicrobial therapy. If these points are taken and an increased awareness of the role of the anaerobes in certain pathological conditions of the lower respiratory tract is generated, we might hope either to produce a meaningful parallel to the experience of our American colleagues--or to structure a more valid defence to explain our lack of experience of these infections in the lower respiratory tract.

Bacterial Infections↗
PubMed1977

Recovery of anaerobic bacteria from small inocula: a model for blood culture studies.

The recovery of anaerobic, facultative anaerobic, and aerobic pathogens from very small inocula was studied under conditions that could be related to routine blood culture procedures. Results with Brain Heart Infusion broth were unsatisfactory. Freshly prepared Brewer thioglycollate medium gave apparently good results, but there are disadvantages when this medium is used for blood culture. Results with Difco Thiol broth were disappointing. A modification of Robertson's cooked-meat broth supplemented with Brain Heart Infusion gave good recovery and sustained viability with a wide range of test organisms including exacting strains. The findings raise points of practical importance.

Bacteria↗
PubMed1976

Tests of performance of anaerobic jars.

This paper briefly reviews methods of assessing the in-use performance of anaerobic jars and outlines a simple system combining a rapid test of catalytic activity with a biological indicator that can detect defects in the jars after incubation.

Anaerobiosis↗
PubMed1975

The production of neuraminidase by food poisoning strains of Clostridium welchii (C. perfringens).

The production of neuraminidase by a classical strain of Clostridium welchii (C. perfringens) type A was studied. Good yields were produced in 5% Proteose Peptone-water medium (PPW5); the enzyme was essentially extracellular but some further neuraminidase could be released by ultrasonic disintegration of the cells. This also released N-acyl neuraminic acid-aldolase (NAN-aldolase) and the degree to which this interferes with the assay for neuraminidase was evaluated. Forty-one British reference food-poisoning strains of C. welchii type A were examined for extracellular neuraminidase production in PPW5. Twelve of 17 strains that produce so-called heat-sensitive spores were neuraminidase positive whereas 20 of 24 strains that are non-haemolytic and produce very heat-resistant sporeswere neuraminidase negative. Variation was found in the ability to produce neuraminidase among strains of a single Hobbs' serotype; four Hobbs' type-13 strains produced neuraminidase but a fifth did not. Disruption of the cells of a Hobbs' type-2 strain that did not produce any extracellular neuraminidase released NAN-aldolase but there was no evidence of cell-associated neuraminidase. British food-poisoning strains of C. welchii type A thus include some that are clearly neuraminidase positive and some that still cannot be shown to produce neuraminidase. There is no correlation between lack of neuraminidase production and the ability to cause food poisoning, although the majority of non-haemolytic heat-resistant strains do not produce neuraminidase. It remains possible that neuraminidase may play a part in C. welchii gas gangrene; it is suggested that the ability to define neuraminidase-negative strains may now be of value in investigating this possibility.

Clostridium perfringens↗
PubMed1974

The recovery of anaerobic bacteria from swabs.

When a standard sample of simulated exudate containing known numbers of anaerobic bacteria was taken up on a swab and plated on solid medium, the number of colonies subsequently cultured represented a very small proportion of the original sample. Evidence is produced that the apparent loss is not primarily attributable to inactivation on the swab but rather to retention of organisms on the swab. This was demonstrable with Clostridium welchii and with Bacteroides species that have hitherto been regarded as relatively oxygen-sensitive.When stock strains of Bacteroides species were held for some hours on swabs, some progressive loss of viability was demonstrable. A measure of protection was afforded when these organisms were held aerobically on blood agar medium, but a very exacting anaerobe and some wild strains of faecal anaerobes showed gradual inactivation under these conditions.These findings may have important implications in relation to currently employed bacteriological sampling procedures with swabs in clinical practice.

Aerobiosis↗