Positive stain for light and electron microscopic demonstration of spirochetes in subgingival plaque and crevicular fluid samples from periodontal diseased sites

Silver stains for the light and electron microscopic demonstration of spirochete changes in syphilis and AIDS

Two new silver stains have been developed in our laboratories to stain, and possibly identify without culture or immunocytochemical staining, Gram(-) bacteria. The first is the PATS reaction which positively stains Gram(-) bacteria (Figs. 1, 2) including those like spirochetes which are difficult to culture. Another stain for Gram(-), as well as Gram(+), bacteria is a variation of the Gram stain. Ordinarily to stain Gram(+) bacteria, and not Gram(-) bacteria, the crystal violet stain is removed from Gram(-) microbes by rinsing with alcohol/acetone. If this rinse step is omitted, the crystal violet iodide remains attached to both the (+) and (-) microbes. It can then be rendered insoluble, electron opaque and conductive by treatment with silver methenamine solution under microwave irradiation. This procedure has been found especially useful in certain cases to demonstrate spirochetes; it appears to be a more effective silver stain than the PATS reaction forTreponema pallidum, the microbe causing syphilis.

ElevatedCandida albicansscores obtained by microscopic examination of subgingival plaque from atypical periodontal disease sites in immunocompromised states (especially AIDS)

Gingivitis and periodontitis have immunologic aspects that can influence or be influenced by the pathogenic microbiota present. In immunocompromised states, especially AIDS, an abnormal gingivitis (HIV-G) and periodontitis (HIV-P) are known. Although acute periodontal lesions generally respond to conventional therapy, in AIDS patients the atypical lesions may also be present which deteriorate further.Candida albicans(CA) lesions of the oral mucosa (not due to diabetes, cancer chemotherapy, radiation therapy or antibiotics) were present in almost all AIDS patients and were helpful in defining this disease. In 1988 it was shown that CA could be cultured from a greater percentage of the atypical than the conventional gingivitis or periodontitis sites in AIDS patients but this required many hours and could not show the relative number of CA present in the different sites.

Microwave-accelerated cytochemical stains for the image analysis and the electron microscopic examination of light microscopy diagnostic slides

Recent studies in our laboratories have shown how microwave (MW) irradiation can accelerate a number of tissue-processing techniques, especially staining, to aid in the preparation of single specimens on glass microscope slides or coverslips for examination by light microscopy (and electron microscopy, if required) for diagnostic purposes. Techniques have been developed, which give permanently stained preparations, that can be studied initially by light microscopy, their areas of interest mapped, and computer-automated image analysis performed to obtain quantitative information. This is readily performed after MW-accelerated staining with silver methenamine by the Giammara-Hanker PATS or PATS-TS reaction. This variation of the PAS reaction gives excellent markers for specific infectious agents such as lipopolysaccharides for gram-negative bacteria or mannans for fungi. It is also an excellent stain for glycogen and basement membranes and an excellent marker for type III collagen or reticulin in the endoneurium or perineurium of peripheral nerve or in the capillary walls. Our improved MW-accelerated Feulgen reaction with silver methenamine for nuclear DNA is useful to show the nuclei of bacteria and fungi as well as of cells they are infecting. Improved coating and penetration of tissue surfaces by thiocarbohydrazide bridging of ruthenium red, applied under MW-acceleration, render biologic specimens sufficiently conductive for SEM so that sputter coating with gold is unnecessary. The specimens treated with these highly visible electron-opaque stains can be screened with the light microscope after mounting in polyethylene glycol (PEG) and the structures or areas selected for EM study are mapped with a Micro-Locator slide. After removal of the water soluble PEG the specimens are remounted in the usual EM media for scanning electron microscopy (SEM) or transmission electron microscopy (TEM) study of the mapped areas. By comparing duplicate smears from areas of infection, such as two coverslips of buffy coat smears of blood from a patient with septicemia, the microorganisms responsible can occasionally be classified for antimicrobial therapy long before culture results are available; gram-negative bacteria are positive with the Giammara-Hanker PATS-TS stain, and gram-positive bacteria are positive with the SIGMA HT40 Gram stain. The gram-positive as well as gram-negative bacteria are both initially stained by the crystal violet component of the Gram stain. The crystal violet stain is readily removed from the gram-negative (but not the gram-positive) bacteria when the specimens are rinsed with alcohol/acetone. If this rinse step is omitted, the crystal violet remains attached to both gram-negative and gram-positive bacteria. It can then be rendered insoluble, electron-opaque, and conductive by treatment with silver methenamine solution under MW-irradiation. This metallized crystal violet is a more effective silver stain than the PATS-TS stain for a number of gram-negative spirochetes such as Treponema pallidum, the microbe that causes syphilis.