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J M Slack

Publications and source records attributed to J M Slack.

At least 127 records · Page 7Linked to original sources
PubMed1974

Predominant gram-positive bacteria in human feces: numbers, variety, and persistence.

The predominant gram-positive bacteria in 47 fecal specimens from 10 healthy men were studied by microscopic and cultural counts, by the characterization and tentative identification of isolates, and by the use of fluorescein isothiocyanate (FITC)-conjugated globulins prepared using some of the isolates. Gram-positive bacteria averaged 10(10.5+/-0.4(sd)/g (wet weight) of feces with significant variation from host to host. Characterization of 865 isolates, all strict anaerobes and carbohydrate fermenters, showed 12 to 39 distinguishable strains from each host and indicated that some strains were present the full period of about 18 months. Sixty percent of the isolates belonged to one of five types, tentatively identified with five species-Bifidobacterium adolescentis, Eubacterium aerofaciens, E. rectale, Peptostreptococcus productus, and Ruminococcus bromii. There was distinct host idiosyncrasy in the pattern of estimated counts of these five types. Certain strains resembling B. adolescentis, E. aerofaciens, and P. productus, distinguished with FITC conjugates, were resident in their hosts for many months. In direct smears each strain constituted about 1% of the total bacteria.

Adult↗
PubMed1969

Identification of human strains of Actinomyces viscosus.

Catalase-positive actinomycetes which closely resemble the "hamster organism" described by Howell have been isolated from dental calculus and other human sources. These cultures could not be distinguished from the hamster strains on the basis of morphology, oxygen requirements, biochemical reactions, or cell wall composition. These human isolates have been classified with the hamster strains as Actinomyces viscosus. The strains from hamster and human sources fell into two serotypes. Serotype 1 contains the hamster strains plus one strain of unknown origin, whereas serotype 2 contains all of the human strains.

Actinomyces↗
PubMed1969

Morphological, biochemical, and serological studies on 64 strains of Actinomyces israelii.

A comparative study of 64 strains of Actinomyces israelii was done with the use of techniques standardized by the Subgroup on Taxonomy of the Microaerophilic Actinomycetes. Emphasis was placed on the range of variation to assist recognition of clinical isolates and aid in differentiation from Actinomyces-like organisms. None of the strains was positive for catalase or indole, or in the Voges-Proskauer test; 90% were methyl red-positive and 62% were nitrate-positive. Acid was produced from: glucose (100%), xylose (100%), salicin (98%), raffinose (95%), lactose (89%), cellobiose (83%), mannose (78%), arabinose (76%), inositol (58%), mannitol (48%), starch (31%), glycogen (0%), glycerol (0%), and rhamnose (0%). A. israelii can be identified by the fluorescent-antibody method, but there is no single morphological or biochemical characteristic which can be used for its identification. By both fluorescent-antibody and gel-diffusion techniques, the serological classification of A. israelii group D with serotypes 1 and 2 was verified. Eleven serotype 2 strains were compared morphologically, biochemically, and serologically with 53 serotype 1 strains. All but two of the serotype 2 strains produced viscous growth in broth and none fermented arabinose.

Actinomyces↗
PubMed1969

Toxin production in Clostridium botulinum as demonstrated by electron microscopy.

Spheroplasts of Clostridium botulinum 62A were prepared with the use of lysozyme. These spheroplasts were then exposed to ferritin-labeled type A antitoxin. Ultrathin sections of these specimens revealed the ferritin-labeled antibody symmetrically arranged around the outer spore coats but not within the spore cortex. The ferritin-labeled antibody was also observed in the bacterial cytoplasm. Here it was arranged in aggregates and strands, although it was not associated with any identifiable cell structure. Controls included sections of C. botulinum spheroplasts treated with a 1.5% solution of ferritin as well as spheroplasts of C. roseum and Bacillus subtilis treated with conjugated type A antitoxin or a 1.5% solution of ferritin. No intracellular or extracellular ferritin was demonstrable in these specimens.

Antitoxins↗
PubMed1968

Quantitative analysis of Actinomyces cell walls.

Quantitative data on the amino acid composition of cell walls of five species of Actinomyces were obtained by using a Beckman-Spinco amino acid analyzer. The major amino acids in A. israelii, A. naeslundii, A. eriksonii, and A. bovis species included alanine, glutamic acid, lysine, aspartic acid, and ornithine, as reported by previous workers, whereas A. propionicus contained diaminopimelic acid. Other amino acids, including glycine, valine, leucine, proline, isoleucine, and threonine, were present in at least some of the walls in quantities equal to or slightly less than that of lysine. This raised the question of whether these may represent cross-links in the peptidoglycan or other cell wall structural components or whether the wall preparations contained nonpeptidoglycan material despite the use of electron microscopy as a standard of purity; further work is required to supply the answer. The quantitative data furnish relative molar concentrations of amino acids, which can provide definitive identification of some of the species and differentiation of Actinomyces from other members of the Actinomycetales and from morphologically similar genera such as Corynebacterium and Propionibacterium.

Actinomyces↗
PubMed1967

Isolation and characterization of Actinomyces propionicus.

Three cultures of Actinomyces have been identified as Actinomyces propionicus. Two of these strains are recent isolates, one, 427, from a case of cervico-facial actinomycosis, and one, 439, from a case of lacrimal canaliculitis. The third strain, 346, was described by F. Lentze as A. israelii serological type II. These three strains were compared with the type strain of A. propionicus ATTC 14157 and with known strains of five other Actinomyces species. Morphologically and biochemically the three new cultures of A. propionicus were identical with the type strain but closely resembled A. israelii. In serological tests making use of fluorescent antibody, all four A. propionicus strains gave negative results with antisera for A. israelii, A. bovis, A. naeslundii, and A. eriksonii, but gave positive results with antisera for A. propionicus 14157 and strain 346. The A. propionicus antisera did not stain other Actinomyces species. A. propionicus contains diaminopimelic acid (DAP) in its cell wall and produces propionic acid from glucose. All three new isolates were shown to contain DAP and to produce propionic acid. By use of the presence of DAP in the cell wall and serological tests as the differential criteria, the three cultures described in the report were specifically identified as A. propionicus.

Actinomyces↗
PubMed1966

Hyper-reactivity of rabbits sensitized with Bartonella bacilliformis.

Mitchell, Paul D. (West Virginia University Medical Center, Morgantown), and John M. Slack. Hyper-reactivity of rabbits sensitized with Bartonella bacilliformis. J. Bacteriol. 92:769-779. 1966.-Sensitization with viable cells of Bartonella bacilliformis increased the susceptibility of rabbits to the lethality of subsequently administered Bartonella metabolites. In animals sensitized with 3 weekly doses of the organism, this susceptible state of hyper-reactivity was maximal between 4 and 14 days postsensitization (primary hyper-reactive state) and persisted for at least 4 weeks, after which the animals were nonreactive (tolerant state). However, on the 84th day, the susceptible state could once again be demonstrated (secondary hyper-reactive state). Animals sensitized with only 1 or 2 weekly doses of the organism were rendered nearly as susceptible, but the time interval between the primary and secondary states of hyper-reactivity was much shorter, indicating that the hyper-reactive states were dependent upon the degree of sensitization. Symptoms displayed by such animals demonstrated an association with endotoxic shock and an anaphylactic or immediate hypersensitive response, the reaction frequently being severe enough to lead to the death of the animal within 24 hr. The histological findings were those of the generalized Shwartzman phenomenon with indications of shock. Such hyper-reactive animals produced an early-occurring, precipitating antibody specific for the somatic, endotoxic component of various gram-positive microorganisms. Injection of sera from the hyper-reactive animals into normal, nonsensitized animals resulted in a passive, hyper-reactive state in the latter animals. A distinct relationship between the levels of specific antibody and the degree of demonstrable hyper-reactivity was observed. This relationship is discussed relative to the histological findings of the hyper-reactive animals.

Animals↗
PubMed1961

SEROLOGICAL GROUPING OF ACTINOMYCES BY MEANS OF FLUORESCENT ANTIBODIES.

Slack, John M. (West Virginia University, Morgantown), Ann Winger, and Dane W. Moore, Jr. Serological grouping of actinomyces by means of fluorescent antibodies. J. Bacteriol. 82:54-65. 1961.-Serological groups A, B, C and D of actinomyces were established using fluorescent antibody techniques. One hundred and thirty-eight cultures were included in the study. Eighty-nine were classed in group A, 15 in B, 13 in C, and 21 in D. The isolates were from patients and animals with actinomycosis and from healthy human beings. There was no correlation between source of the isolate and serological group. Furthermore, no one species could be placed exclusively in one group although the majority of those designated as Actinomyces bovis were in group A. Seventeen anaerobic diphtheroids and seven Corynebacterium acnes isolates were placed in group A. One diphtheroid was in each of groups B and D. On this basis it is suggested that these organisms be included in the genus Actinomyces.Additional species of Corynebacterium as well as Lactobacillus Propionibacterium, Streptomyces, and Nocardia did not fluoresce with any of the group antisera.

Journal Article↗
PubMedDate not supplied

Mesoderm induction in early Xenopus embryos by heparin-binding growth factors.

In early embryonic development the basic body plan arises because cells in different regions become programmed to follow different developmental pathways. We have proposed that in the early amphibian embryo this process of regional specification arises from the action of three different inducing factors, or morphogens, but we have not until now had any idea of their chemical nature. In this paper we report that pure basic fibroblast growth factor (bFGF), at very low concentrations and with high specificity, closely mimics the effect of the ventrovegetal (VV) signal and that the transmission of the natural VV signal can be blocked by heparin, suggesting that it may be a heparin-binding factor such as bFGF.

Animals↗