29) Which group of microorganisms is most likely to spoil a freshwater trout preserved with salt? B) Facultative halophiles 30) Which of the following is an organic growth factor? B) Vitamin B1 31) Which of the following is an example of a metabolic activity that could be used to measure microbial growth B) Glucose consumption 32) An experiment began with 4 cells and ended with 128 cells. How many generations did thecells go through? D) 5 33) Three cells with generation times of 60 minutes are inoculated into a culture medium. How many cells are there after 5 hours? C) 96 Figure 6.3 34) In Figure 6.3, which tube shows the expected growth pattern for a microaerophile?E 35) In Figure 6.3, which tube shows the expected growth pattern for a facultative anaerobe?B 36) 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 serotype 10 was not isolated from the detergent, glutaraldehyde, or tap water. What was the source of the infections? B) A biofilm in the reprocessor Table 6.1: Three different culture media are shown below. Medium A Medium B Medium C FNa 2 HPO 4 Tide detergent Glucose
KH2 PO 4 Na2 HPO 4 Peptone MgSO4 KH2 PO 4 (NH4 ) 2 SO 4 CaCl2 MgSO4 KH2 PO 2 NaHCO3 (NH4 ) 2 SO 4 Na2 HPO 4 37) For the three types of media in Table 6.1, which medium (or media) is/are chemically defined?A 38) In Table, 6.1, in which medium (or media) would an autotroph grow?A 39) Assume you inoculated 100 cells, with a generation time of 20 minutes, into 100 ml of nutrient broth. You then inoculated 100 cells of the same species into 200 ml of nutrient broth. After incubation for 4 hours, you can reasonably expect to have C) The same number of cells in both. 40) The source of nutrients in nutrient agar is C) Peptone and beef extract. 41) Which enzyme catalyzes the reaction: O2- + O2- + 2H+→ H2O2+ O2? D) Superoxide dismutase 42) Which enzyme catalyzes the reaction: 2H2O2 → 2H2O + O2? A) Catalase 43) Which enzyme catalyzes the reaction: H2O2+ 2H+→ 2H2O? C) Peroxidase 44) Table 6.2 The following data show growth of two bacteria on different media. The data in Table 6.2 indicate that S. aureus is a (n) C) Facultative halophile. 45) Patients with indwelling catheters (long-term tubes inserted into body orifices for drainage, such as through the urethra and into the urinary bladder) are susceptible to infections because Answer: D 6.3 Essay Question A patient with a heart pacemaker received antibiotic therapy for streptococcal bacteremia (bacteria in the blood). One month later, he was treated for recurrence of the bacteremia. When he returned six weeks later, again with bacteremia, the physician recommended replacing the pacemaker. Why did this cure his condition?
- Spring '19