End of Chapter 7 Questions Micro

Stationary Phase

No population growth observed. Cells die and are generated at an equal rate. Cells that can form spores prepare to do so

death phase

No population growth observed. Rate of cell death exceeds cell division

ou have a patient who is suffering from a Clostridium difficile infection. Which of the following would most likely be recommended to decontaminate small heat-stable equipment used for the patient? Autoclave all equipment at 121°C for 15 minutes. Boil equipment for three minutes. Place the equipment in a hot-air oven at 121°C for 15 minutes. Treat all equipment with a detergent solution. None of the above.

None of the above

You are collecting a clinical sample for microbiological analysis. Which of the following is the most important thing you must do?

Refrigerate the samples immediately after collection

Which of the following is (are) true?

Scalpels are critical equipment, Stethoscopes are noncritical equipment, Anesthesia tubing is semicritical equipment.

In a closed batch system, not all cells are expected to die even as the death phase advances. Why?

Some cells adapt to utilize nutrients from dead cells and withstand the accumulated waste

a Salmonella species is grown for 8 hours. In this time, each cell divides about four times. What is the generation time?

2 hours

Sterilization

A form of decontamination. Autoclaving surgical equipment. Treatment needed for critical equipment

Disinfection

A form of decontamination. Wiping bedrails with a low level germicide

microbes use oxygen in metabolism, while do not.

Aerobic, anaerobic

Which of the following pathogens would hyperbaric oxygen therapy, a treatment that increases the level of dissolved oxygen in tissues, most likely ward off? Select all that apply.

Anaerobic mesophile and Microaerophilic mesophile

Log Phase

Cells are acclimating to their environment. No population growth observed

You are collecting a sample from a deep wound for analysis by the clinical microbiology lab. Which of the following is not a consideration as you undertake this process?

Disinfecting the tube before collecting the sample

If you were a manufacturer of electronic pacemakers for heart implantation, which agent would you most likely use to treat your product?

Ethylene oxide

A bacterial specimen exhibits the following growth on blood agar. What can you most reasonably conclude about the bacterium? Select all answers that apply.

It is not S. pyogenes and It is Gram-positive

Log Phase

The period of exponential growth of bacterial population.

Which direct enumeration method differentiates living from nonliving cells?

Viable plate count

Antisepsis

a form of decontamination using genocide on a living tissue

The is the time needed to kill 90 percent of a given microbial population at a set temperature. The is the lowest temperature needed to kill all microbes in a sample within ten minutes.

decimal reduction time, thermal death point

Choose the false statement about binary fission.

generates genetically diverse daughter cells.

choose the false statement about turbidity as an enumeration method.

it differentiates between live and dead cells.

If a bacterium that normally lives in the gastrointestinal tract is plunged into a salty solution, __________________ would occur.

plasmolysis

After performing the streak plate method, what feature(s) would you look for on the agar plate to determine if you have a pure culture?

shape, color, sheen, and texture