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Biomedical subjects

J G Atherton

Publications and source records attributed to J G Atherton.

At least 19 recordsLinked to original sources
PubMed1991

Isolation of a bacterium resembling Pirellula species from primary tissue culture of the giant tiger prawn (Penaeus monodon).

During attempts to establish tissue cultures from hepatopancreas, heart, and hemolymph of the giant tiger prawn (Penaeus monodon), using a medium including penicillin, streptomycin, and amphotericin B, bacterial contamination in the form of a sheet of growth attached to the tissue culture vessel was a persistent problem. Contaminant bacteria were teardrop-shaped cells arranged in rosettes, and electron microscopy revealed buds, crateriform structures, and the absence of a peptidoglycan layer in the cell wall, features characteristic of bacteria in the Planctomyces-Pirellula group, a phylogenetically distinct group of eubacteria. Two strains of contaminant bacteria were isolated in pure culture. Both exhibited morphology and antibiotic resistance consistent with their membership in the Planctomyces-Pirellula group (order Planctomycetales) of eubacteria. Tissue culture media for marine invertebrates may select for such bacteria if high concentrations of cell wall synthesis-inhibiting antibiotics are included.

Animals↗
PubMed1982

Types of Pseudomonas aeruginosa isolated from horses.

Pseudomonas aeruginosa isolates from equine clinical material were categorised according to their serotype and phage type. Epidemiological evidence showed that serotypes 02a, 03, 04, 06, 09 and 010 were the cause of genital and non-genital infections; somatic type 03 accounted for 50 per cent of isolates. The laboratory tests used were of no value in predicting whether or not a particular isolate was likely to be a venereal pathogen, but all the serotypes encountered had the potential to be pathogenic, given a favourable environment in which to multiply.

Animals↗
PubMed1978

The experimental infection of ponies with contagious equine metritis.

Four pony mares were readily infected with the organism of contagious equine metritis by intracervical inoculation and one by coitus with an infected stallion. Infected mares developed an acute endometritis with local destruction of the endometrial epithelium. In 2 experimentally infected mares, infection appeared to have been spontaneously eliminated from the genital tract within 3 to 4 weeks. A third mare however remained persistently infected in the clitoral fossa over a long period and was a symptomless carrier. Four pony stallions were readily infected in the urethral fossa and the organism survived for varying periods without giving rise to any signs of infection. From 2 of these animals it appeared eventually to have been eliminated spontaneously. An experimentally infected stallion transmitted infection to a healthy mare by coitus. Bacteriological examination of infected pony stallions may occassionally give false negative results and fail to reveal the organism in the external genitalia. Repeated bacteriological examinations need to be undertaken before it can be concluded that a stallion is free of infection.

Animals↗
PubMed1976

Klebsiella and Enterobacter organisms isolated from horses.

An account is given of K. pneumoniae capsule types occurring in horses, with particular reference to strains originating from the genital tract in the mare and the external genitalia of the stallion. A survey of the prevalence of K. pneumoniae and E. aerogenes strains in the preputial flora of healthy stallions is described. The majority of horses were found to be carriers of these organisms. The cultural characteristics of these preputial strains are described and compared with those of K. pneumoniae strains associated with epidemic metritis in mares. The epidemiological significance of certain K. pneumoniae capsule types is discussed.

Animals↗
PubMed1965

Mechanism of Polykaryocytosis Associated with Noncytopathic Infection by Measles Virus.

Atherton, John G. (University of Southern California, Los Angeles), Sotiros G. Chaparas, Martha Cremer, and Irving Gordon. Mechanism of polykaryocytosis associated with noncytopathic infection by measles virus. J. Bacteriol. 90:213-219. 1965.-Infection with a measles virus variant resulted not only in formation of polykaryocytes (PK) but also in formation of multicellular immunofluorescent foci (IFF) in which no cytopathic effect could be detected. The ratio of IFF to PK changed from 27 to 4 during the first passage and remained 4 after a second passage. PK were plaques. Plaque assay was linear in the presence of IFF. To investigate the mechanism of PK formation, radioautography was done on cells pulse-labeled with tritiated thymidine before virus multiplication began. The results showed that PK were formed by fusion; there were no PK whose nuclei contained no label, and the proportion of labeled nuclei (32%) and distribution of grain counts was the same in PK as in uninvolved cells, ruling out nuclear replication without concomitant cytoplasmic membrane formation as the mechanism of formation of these PK. Early in PK development, neutral red uptake was markedly increased ("red" plaques). As PK matured, hyperchromicity disappeared ("white" plaques). This sequence provided an index of rate of evolution of PK. Rate of PK maturation was more rapid at 37 than at 32 C.

Journal Article↗