Exam 6: Microbial Growth

Figure 6.4 -In each graph in Figure 6.4, the culture was incubated at 30°C in glucose- minimal salts broth, aerobically. The bacterium is a facultative anaerobe with an optimum temperature of 37°C and can metabolize glucose and lactose. Indicate how each growth curve would change under the conditions indicated in each graph. Draw the new graphs, or write "no change."

During which growth phase will gram- positive bacteria be most susceptible to penicillin?

Patients with indwelling catheters are susceptible to infections because

Figure 6.2 -Figure 6.2 shows a typical bacterial growth curve with the x- axis indicating the log of the number of bacteria and the y- axis indicating time in culture. In the figure, which sections of the graph illustrate a logarithmic change in cell numbers?

Which of the following is an organic growth factor?

A culture medium on which only gram- positive organisms grow and a yellow halo surrounds Staphylococcus aureus colonies is called a(n)

Which of the following is an advantage of the direct microscopic count?

Table 6.1 Three different culture media are shown below. Medium A Medium B Medium C Tide detergent Glucose Peptone -For the three types of media in Table 6.1, which medium (or media) is/are chemically defined?

Figure 6.3 -In Figure 6.3, which tube shows the expected growth pattern for a facultative anaerobe?

Which of the following is an example of a metabolic activity that could be used to measure microbial growth?

Laboratory cultivation of obligate anaerobes requires reducing media or special growth chambers filled with inert gases.

The biosafety level (BSL) for a clinical microbiology laboratory working with potentially airborne pathogens, such as tuberculosis bacteria, is

In one hospital, Pseudomonas aeruginosa serotype 10 infected the biliary tract of 10 percent of 1300 patients who underwent gastrointestinal endoscopic procedures. After each use, endoscopes were washed with an automatic reprocessor that flushed detergent and glutaraldehyde through the endoscopes, followed by a tap water rinse. P. aeruginosa 10 was not isolated from the detergent, glutaraldehyde, or tap water. What was the source of the infections?

Pathogenic bacteria isolated from the respiratory or intestinal tracts of humans are

The term aerotolerant anaerobe refers to an organism that

The source of nutrients in nutrient agar is

Salts and sugars work to preserve foods by creating a