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Fusobacterium Hemolysis

Figure 44-7 Clostridium petfrmgens on anaerobic blood agar. Note Figure 44-8 Gram stain of Fusobacterium nucleatum subsp. double zone of beta hemolysis. 1, First zone; 2, second zone. nudeatum. Note pointed ends.

(Courtesy Anaerobe Systems, Morgan Hill, Calif.)

Figure 44-7 Clostridium petfrmgens on anaerobic blood agar. Note Figure 44-8 Gram stain of Fusobacterium nucleatum subsp. double zone of beta hemolysis. 1, First zone; 2, second zone. nudeatum. Note pointed ends.

(Courtesy Anaerobe Systems, Morgan Hill, Calif.)

Figure 44-9 Fusobacterium nucleatum subsp. nuckatum on anaerobic blood agar. Note breadcrumb-like colonies and greening of agar.

Fusobacterium Nucleatum Colonies

Figure 44-10 Peptostreptococcus anaerobius on anaerobic blood agar.

Figure 44-9 Fusobacterium nucleatum subsp. nuckatum on anaerobic blood agar. Note breadcrumb-like colonies and greening of agar.

Figure 44-10 Peptostreptococcus anaerobius on anaerobic blood agar.

Fusobacterium Nucleatum Colonies

Figure 44-11 Porphyromonas spp. on anaerobic blood agar. Red fluorescence under ultraviolet light (365 nm}. (Courtesy Anaerobe Systems, Morgan Hill, Calif.)

Figure 44-12 Prevotella disiens on laked kanamydn-vancomydj| blood agar. Note black pigment (arrow).

Figure 44-11 Porphyromonas spp. on anaerobic blood agar. Red fluorescence under ultraviolet light (365 nm}. (Courtesy Anaerobe Systems, Morgan Hill, Calif.)

Figure 44-12 Prevotella disiens on laked kanamydn-vancomydj| blood agar. Note black pigment (arrow).

examined with a hand lens (x8) or, preferably, a stereoscopic microscope. Colonies should be described from the various media and semiquantitated.

All colony moiphotypes from the nonselective anaerobic blood agar should be characterized and sub-cultured to purity plates, because facultative and obligately anaerobic bacteria frequendy have similar colonial appearances. Colonies on the PEA (phenylethyl alcohol agar) are processed further only if they are different from colonies growing on the anaerobic blood agar or if colonies on the anaerobic blood agar are impossible to subculture because of overgrowth by swarming Clostridia, Proteus, or other organisms.

The backup broth (e.g., thioglycollate) should be Gram-stained; if cellular types are seen that were not present on the primary plates, the broth should be subcultured.

subculture of isolates

A single colony of each distinct morphotype is examined microscopically using a Gram stain and is sub-cultured for aerotolerance testing. A sterile wooden stick or platinum loop should be used to subculture colonies to:

  • A chocolate agar plate to be incubated in carbon dioxide (C02)
  • An anaerobic blood agar plate to be incubated anae-

robically (purity plate)

The chocolate agar plate should be inoculated first, so that if only the anaerobic blood agar plate grows, there is no question of not having enough organisms to initiate growth. The following antibiotic identification disks are placed on the first quadrant of the purity plate (Procedure 44-1): Kanamycin, I mg Colistin, 10 ng Vancomycin, 5 (xg

These disks aid in preliminary grouping of anaerobes and serve to verify the Gram stain, but they do not imply susceptibility of an organism for antibiotic therapy.

Three other disks may be added to the anaerobic blood agar plate at this time. A nitrate disk may be placed on the second quadrant for subsequent determination of nitrate reduction. A sodium polyanethol-sulfonate (SPS) disk can be placed near the colistin disk for rapid presumptive identification of Peptostreptococcus anaerobius if gram-positive cocci are seen on Gram stain. A bile disk may be added to the second quadrant to detect bile inhibition if gram-negative rods are seen on Gram stain.

If processing is performed on the open bench, all P^tes should promptly be incubated anaerobicaDy, because some clinical isolates (e.g., Fusobacterium necro-phorum subsp. necrophorum and some Prevotella spp.) may die after relatively short exposure to oxygen. The primary plates are reincubated along with the purity plates for an additional 48 to 72 hours and are again inspected for slowly growing or pigmenting strains.

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Bacterial Vaginosis Facts

Bacterial Vaginosis Facts

This fact sheet is designed to provide you with information on Bacterial Vaginosis. Bacterial vaginosis is an abnormal vaginal condition that is characterized by vaginal discharge and results from an overgrowth of atypical bacteria in the vagina.

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