Liquid Media

In general, the use of a liquid media system reduces the turn-around time for isolation of acid-fast bacilli to approximately 10 days, compared with 17 days or longer for conventional solid media.2'9,19 There are several different systems to culture and detect the growth of mycobacteria in liquid media. The most commonly used systems are summarized in Table 45-8. Growth of mycobacteria in liquid media, regardless of the type, requires 5% to 10% C02; C02 is either already

Mycobacterium Fortitum Colonies

Figure 45-3 Typical appearance of some mycobacteria on solid agar medium. A, M. tuberculosis colonies on Lôwenstein- Jensen agar after 8 weeks of incubation. B, Different colonial morphology seen on culture of one strain of Ai. avium complex. C, M. kansasii colonie^ exposed to light. D, Scotochromogen M. gordonae with yellow colonies. E, Smooth, multilobate colonies of M.fortuitum on Lôwenstei^j Jensen medium.

Figure 45-3 Typical appearance of some mycobacteria on solid agar medium. A, M. tuberculosis colonies on Lôwenstein- Jensen agar after 8 weeks of incubation. B, Different colonial morphology seen on culture of one strain of Ai. avium complex. C, M. kansasii colonie^ exposed to light. D, Scotochromogen M. gordonae with yellow colonies. E, Smooth, multilobate colonies of M.fortuitum on Lôwenstei^j Jensen medium.

fgbtr 45-8 Commonly Used Liquid Media Systems to Culture and Detect the Growth of Mycobacteria

1 system

Basic Principles of Detection

3ACTEC 460 TB (Becton Dickinson Diagnostic Systems, Cockeysville.Md)

Culture media contains "C-labeled palmitic acid. If present In the broth, mycobacteria metabolize the "C-labeled substrates and release radioactiveiy labeled ,4C02 in the atmosphere, which collects above the broth in the bottle. The instrument withdraws this aVcontainlng atmosphere and measures the amount of radioactivity present Bottles that yield a radioactive index, called a growth index, greater than or equal to 10 are considered positive.

Septi-Chek AFB System (Becton Dickinson)

Biphasic culture system made up of a modified Middlebrook 7H9 broth with a three-sided paddle containing chocolate, egg-based, and modified 7H11 solid agars. The bottle is inverted regularly to inoculate the solid media. Growth is detected by observing the three-sided paddle.

Mycobacteria Growth Indicator Tube (MGIT) (Becton Dickinson)

Culture tube contains Middlebrook 7H9 broth and ^ fluorescent compound embedded in a silicone sensor. Growth is detected visually using an ultraviolet light. Oxygen (OJ diminishes the fluorescent output of the sensor, therefore, 0-, consumption by organisms present in the medium are detected as an increase in fluorescence.

Continuous Growth Monitoring Systems

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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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