Techniques for controlling variability in gram staining of obligate anaerobes.

AUTOR(ES)

Johnson, M J

RESUMO

Identification of anaerobes recovered from clinical samples is complicated by the fact that certain gram-positive anaerobes routinely stain gram negative; Peptostreptococcus asaccharolyticus, Eubacterium plautii, Clostridium ramosum, Clostridium symbiosum, and Clostridium clostridiiforme are among the nonconformists with regard to conventional Gram-staining procedures. Accurate Gram staining of American Type Culture Collection strains of these anaerobic bacteria is possible by implementing fixing and staining techniques within a gloveless anaerobic chamber. Under anaerobic conditions, gram-positive staining occurred in all test organisms with "quick" fixing techniques with both absolute methanol and formalin. The results support the hypothesis that, when anaerobic bacteria are exposed to oxygen, a breakdown of the physical integrity of the cell wall occurs, introducing Gram stain variability in gram-positive anaerobes.

Documentos Relacionados

• Pipette count method for obligate anaerobes.
• Thermal adaptation in yeast: obligate psychrophiles are obligate aerobes, and obligate thermophiles are facultative anaerobes.
• The API ZYM system in the identification of Gram-negative anaerobes.
• Compact liquid nitrogen storage system yielding high recoveries of gram-negative anaerobes.
• Preparing inoculum for susceptibility testing of anaerobes.