Radiolabeling of and macromolecular syntheses in Neisseria gonorrhoeae types 1 and 4

Lim, Daniel V.; James, Ann N.; Williams, Robert P.

doi:10.1128/aem.33.2.328-333.1977

Cited by 6 publications

(1 citation statement)

References 12 publications

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“…As mentioned earlier, an increase in treponemal survival time for radiotracer studies could be very advantageous in several respects. For example, assimilation of carbohydrate carbon skeletons into cellular fractions may be observed (1,10). Carbohydrate assimilation by T. pallidum has yet to be demonstrated, although carbohydrate catabolism has been documented (4,20).…”

Section: H4ursmentioning

confidence: 99%

Radiolabeling of Treponema pallidum (Nichols virulent strain) in vitro with precursors for protein and RNA biosynthesis

Sandok¹,

Jenkin²

1978

Infect Immun

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We observed uptake of [U-'4C]serine, U-'4C-labeled amino acid hydrolysates, and [2-'4C]uracil by virulent Treponema pallidum in vitro for at least 96 h. No uptake of [2-'4C]thymine, [1-'4C]pyruvate, [U-14C]pyruvate, and [2-'4C]uridine was detected. Treponemal protein and RNA biosynthetic activity was identified by erythromycin inhibition of amino acid and uracil uptake. Radioactivity due to uptake of radiolabeled amino acids by residual testicular cells in the cultures remained at background levels regardless of the presence or absence of cycloheximide. Accumulation of the radiolabeled substrates by T. pallidum proceeded at a linear rate for 48 to 96 h during incubation in vitro. The longevity of substrate uptake using the system of incubation described will facilitate future studies on the metabolism of the microorganism to help determine essential growth factors and environmental conditions for multiplication of T. pallidum in vitro. Until recently, the most commonly accepted techniques to study the physiology of Treponema pallidum in vitro were dependent upon the use of light microscopy for direct counts and on the exploitation of the rabbit to evaluate retention of virulence by the microorganism (6, 26). Now, it is becoming increasingly apparent that these techniques are not completely satisfactory for physiological studies on T. pallidum in vitro. For example, Baseman and Hayes observed inhibition of radiolabeled amino acid uptake by erythromycin in cultures of T. pallidum

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Section: H4ursmentioning

confidence: 99%

Radiolabeling of Treponema pallidum (Nichols virulent strain) in vitro with precursors for protein and RNA biosynthesis

Sandok¹,

Jenkin²

1978

Infect Immun

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Physiology of Neisseria gonorrhoeae

Morse

Cacciapuoti

Lysko

1980

Advances in Microbial Physiology

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Differences in Susceptibilities of Virulent Strains and Avirulent Strains of Neisseria gonorrhoeae to Antimicrobial Agents

Lim

1978

Antimicrob Agents Chemother

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Virulent cells (Ti colony type) and avirulent cells (T4 colony type) of Neisseria gonorrhoeae were grown in a defined liquid medium in the presence of different antimicrobial agents. Bacteria of Ti colony type were found to be more resistant than bacteria of T4 colony type to the inhibitory effects of specific concentrations of ampicillin (0.50 ytg/ml) and penicillin (0.01 ag/ml). Bacteria of T4 colony type, however, were found to be more resistant to the effects of chloramphenicol (0.40 Itg/ml), erythromycin (0.10 ,ug/ml), spectinomycin (10.00 tig/ml), and tetracycline (0.30 ,tg/ml). The differences in susceptibilities of these bacteria to the antibiotics investigated were not due to differences in growth rate or to differences in permeability. The data suggest that virulent gonococci and avirulent gonococci have unique properties that affect their susceptibilities to certain antimicrobial agents.Gonococcal infections in men and women routinely are treated with antimicrobial agents such as penicillin, ampicillin, tetracycline, or spectinomycin (26). The quantities of these antibiotics used in therapy, however, has increased over the years as their effectiveness in treatment of gonorrhea has diminished (13,24,28). Recently, with the emergence of penicillin-resistant (1, 2, 16) and spectinomycin-resistant (1) strains of Neisseria gonorrhoeae, there has been increased concern that treatment of uncomplicated gonococcal infections with these antibiotics eventually may not be sufficient.Although previous studies have shown that antibiotic resistance may result from plasmidmediated resistance genes (2) or from permeability barriers in the cell (20,22) and that multiple antibiotic resistance is derived from clusters of linked genes on bacterial chromosomes (21, 25), there have been few reports comparing susceptibilities of virulent strains and avirulent strains of N. gonorrhoeae to antimicrobial agents. Such data could provide valuable information on metabolic and morphological differences in these strains of gonococci, as well as an insight into the basis of antibiotic resistance in these bacteria.In this study we describe differences in susceptibilities of virulent (Ti colony type) and avirulent (T4 colony type) strains of N. gonorrhoeae to six antimicrobial agents (ampicillin, chloramphenicol, erythromycin, penicillin, spectinomycin, and tetracycline).MATERIALS

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Radiolabeling of and macromolecular syntheses in Neisseria gonorrhoeae types 1 and 4

Cited by 6 publications

References 12 publications

Radiolabeling of Treponema pallidum (Nichols virulent strain) in vitro with precursors for protein and RNA biosynthesis

Radiolabeling of Treponema pallidum (Nichols virulent strain) in vitro with precursors for protein and RNA biosynthesis

Physiology of Neisseria gonorrhoeae

Differences in Susceptibilities of Virulent Strains and Avirulent Strains of Neisseria gonorrhoeae to Antimicrobial Agents

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