Skip to main content
PMC home page
Journal of Clinical Microbiology logoLink to Journal of Clinical Microbiology
. 1983 Mar;17(3):485–488. doi: 10.1128/jcm.17.3.485-488.1983

Rapid evaluation of gonococcal and nongonococcal urethritis in men with Limulus amoebocyte lysate and a chromogenic substrate.

R B Prior, V A Spagna
PMCID: PMC272671  PMID: 6404928

Abstract

A chromogenic substrate was used with Limulus amoebocyte lysate (LAL) and compared by parallel testing with the traditional gelation LAL method for the rapid evaluation of exudative urethritis in 125 male patients. Of these patients, 67 had positive cultures for Neisseria gonorrhoeae and 58 were negative. The corresponding prevalence of gonococcal urethritis was 53.6%. For assay, diluted urethral samples and chromogenic substrate were added directly to single-test LAL vials, and objective color endpoint determinations were made visually after a 10-min incubation period at 37 degrees C. Sensitivity and specificity were 98.5% and 93.1%, respectively, with an overall accuracy in predicting culture results of 96.0%. The predictive value of a positive LAL test was 94.3% in our patient population; in a population with a prevalence of gonococcal urethritis of only 10%, the predictive value would be 61.3%. Results were not statistically different from those obtained by the 30-min gelation LAL method or by Gram-stained smears read by experienced microscopists (P greater than 0.05). Unlike the delicate gel, the color endpoint was not prone to accidental mechanical disruption during incubation or reading. Thus, use of a chromogenic substrate greatly improved the utility and speed of the LAL assay for evaluating men with exudative urethritis while not affecting the accuracy of the test.

Full text

PDF
486

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Chapel T. A., Adcock M., Smith B., Barnes T., Goodman M. Evaluation of the limulus amebocyte lysate assay for presumptive diagnosis of gonorrhea in men at a clinic for sexually transmitted diseases. Sex Transm Dis. 1981 Jul-Sep;8(3):175–178. doi: 10.1097/00007435-198107000-00001. [DOI] [PubMed] [Google Scholar]
  2. Fleming W. L., Brown W. J., Donohue J. F., Branigin P. W. National survey of venereal disease treated by physicians in 1968. JAMA. 1970 Mar 16;211(11):1827–1830. [PubMed] [Google Scholar]
  3. Goodhart M. E., Ogden J., Zaidi A. A., Kraus S. J. Factors affecting the performance of smear and culture tests for the detection of Neisseria gonorrhoeae. Sex Transm Dis. 1982 Apr-Jun;9(2):63–69. doi: 10.1097/00007435-198204000-00002. [DOI] [PubMed] [Google Scholar]
  4. Iwanaga S., Morita T., Harada T., Nakamura S., Niwa M., Takada K., Kimura T., Sakakibara S. Chromogenic substrates for horseshoe crab clotting enzyme. Its application for the assay of bacterial endotoxins. Haemostasis. 1978;7(2-3):183–188. doi: 10.1159/000214260. [DOI] [PubMed] [Google Scholar]
  5. Jacobs N. F., Kraus S. J. Gonococcal and nongonococcal urethritis in men. Clinical and laboratory differentiation. Ann Intern Med. 1975 Jan;82(1):7–12. doi: 10.7326/0003-4819-82-1-7. [DOI] [PubMed] [Google Scholar]
  6. Kraus S. J. Semiquantitation of urethral polymorphonuclear leukocytes as objective evidence of nongonococcal urethritis. Sex Transm Dis. 1982 Jan-Mar;9(1):52–55. [PubMed] [Google Scholar]
  7. Nachum R., Christiansen R. O. Rapid presumptive diagnosis of gonococcal urethritis in males: evaluation of a prototype limulus lysate test kit. Med Lab Sci. 1982 Jan;39(1):83–85. [PubMed] [Google Scholar]
  8. Nakamura S., Morita T., Iwanaga S., Niwa M., Takahashi K. A sensitive substrate for the clotting enzyme in horseshoe crab hemocytes. J Biochem. 1977 May;81(5):1567–1569. [PubMed] [Google Scholar]
  9. Ohki M., Nakamura T., Morita T., Iwanaga S. A new endotoxin sensitive factor associated with hemolymph coagulation system of horseshoe crab (Limulidae). FEBS Lett. 1980 Nov 3;120(2):217–220. doi: 10.1016/0014-5793(80)80301-2. [DOI] [PubMed] [Google Scholar]
  10. Prior R. B., Spagna V. A. Application of a Limulus test device in rapid evaluation of gonococcal and nongonococcal urethritis in males. J Clin Microbiol. 1981 Sep;14(3):256–260. doi: 10.1128/jcm.14.3.256-260.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Prior R. B., Spagna V. A. Comparative evaluation of the tube and microdilution Limulus lysate techniques for rapid presumptive diagnosis of gonococcal urethritis in men. J Clin Microbiol. 1980 Apr;11(4):340–342. doi: 10.1128/jcm.11.4.340-342.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Prior R. B., Spagna V. A. Response of several Limulus amoebocyte lysates to native endotoxin present in gonococcal and nongonococcal urethral exudates from human males. J Clin Microbiol. 1981 Jan;13(1):167–170. doi: 10.1128/jcm.13.1.167-170.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Scully M. F., Newman Y. M., Clark S. E., Kakkar V. V. Evaluation of a chromogenic method for endotoxin measurement. Thromb Res. 1980 Oct 15;20(2):263–270. doi: 10.1016/0049-3848(80)90391-6. [DOI] [PubMed] [Google Scholar]
  14. Spagna V. A., Prior R. B., Perkins R. L. Rapid presumptive diagnosis of gonococcal urethritis in men by the limulus lysate test. Br J Vener Dis. 1979 Jun;55(3):179–182. doi: 10.1136/sti.55.3.179. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Spagna V. A., Prior R. B. The Limulus amebocyte lysate assay. Am Fam Physician. 1980 Sep;22(3):125–128. [PubMed] [Google Scholar]
  16. Tai J. Y., Liu T. Y. Studies on Limulus amoebocyte lysate. Isolation of pro-clotting enzyme. J Biol Chem. 1977 Apr 10;252(7):2178–2181. [PubMed] [Google Scholar]
  17. Tai J. Y., Seid R. C., Jr, Huhn R. D., Liu T. Y. Studies on Limulus amoebocyte lysate II. Purification of the coagulogen and the mechanism of clotting. J Biol Chem. 1977 Jul 25;252(14):4773–4776. [PubMed] [Google Scholar]
  18. Vecchio T. J. Predictive value of a single diagnostic test in unselected populations. N Engl J Med. 1966 May 26;274(21):1171–1173. doi: 10.1056/NEJM196605262742104. [DOI] [PubMed] [Google Scholar]
  19. Webster C. J. Principles of a quantitative assay for bacterial endotoxins in blood that uses Limulus lysate and a chromogenic substrate. J Clin Microbiol. 1980 Nov;12(5):644–650. doi: 10.1128/jcm.12.5.644-650.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Journal of Clinical Microbiology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES