Chapter 11 Problem Set

T/F: Haemophilus influenzae is a virus that causes the "flu."

False

T/F: Only Gram-positive bacteria can form resting stage structures.

False

Which of the following statements regarding the Enterobacteriaceae are TRUE?

They are Gram-negative rods that form part of the normal microbiota, Their name derives from the fact that they reside in intestinal tracts of humans and animals, They are facultative anaerobes that ferment glucose, Enterobacteriaceae called coliforms ferment lactose.

Corynebacterium species and Enterobacteriaceae family members are examples of ______ anaerobes, meaning that they preferentially use aerobic respiration if O2 is available, but can ferment if it is not.

facultative

Methanogens are a group of archaea that generate ATP by

oxidizing hydrogen gas, using carbon dioxide as terminal electron acceptor.

Which of the following statements about members of the genus Mycoplasma are true?

they are difficult to filter from growth media, they lack a peptidoglycan cell wall, they are unaffected by penicillin.

Which of the following are TRUE regarding coliforms?

they are used as indicators of fecal pollution, they are gram-negative, they are facultative anaerobes, they belong to the family Enterobacteriaceae, they characteristically ferment lactose.

Which organism is NOT classified as a facultative anaerobe?

Psuedomonas aeruginosa

Clostridium difficile

Antibiotic-associated diarrheal disease.

Methanogens

Archaea, live in anaerobic environments with H2 and CO2.

Clostridium botulinum

Botulism, a disease characterized by flaccid paralysis.

What is NOT a member of the Enterobacteriaceae family (Gram-negative rods, glucose fermenters, some members motile with peritrichous flagella, some members lactose fermenting)?

Corynebacterium diphtheriae

Identify which of the following genera have members that are disease-causing facultative anaerobes.

Corynebacterium, Escherichia, Staphylococcus

Clostridium perfringens

Gas gangrene: a disease characterized by necrotic tissue and the production of gas.

Clostridium species

Generally in endospore form in soil, but will germinate to vegetative form when anaerobic conditions arise. Gram-positive rods.

Mycobacterium species

Generally pleomorphic (variable shape) rods that stain poorly and resist destaining due to waxy lipids in their cell wall structure. Several species cause human diseases.

Pseudomonas species

Gram-negative rods with polar flagella. Often produce pigments. Widespread in soil and water. Most are harmless, but some can be opportunistic pathogens of humans.

Micrococcus species

Gram-positive cocci found in soil, dust particles, inanimate objects, skin; tolerates dry and moderately salty conditions.

Propionibacterium species

Gram-positive pleomorphic (irregular shaped) rods, fermenters, often used in Swiss cheese production.

Lactic acid bacteria

Gram-positive, catalase-negative, grow in aerobic environments but only ferment, producing acidic conditions.

Members of this group of microbes can break down glycogen deposited in the vaginal lining in response to estrogen. This helps to drop the pH in the area, preventing infections.

Lactic Acid Bacteria

Which of the statements about chemotrophs is FALSE?

Lactic acid bacteria such as Lactobacillus obtain their ATP by oxidizing glucose, using lactic acid as their terminal electron acceptor.

Select the TRUE statements about obligate aerobes.

Micrococcus species typically form colored colonies, making them easy to identify, Mycobacterium species have an unusual cell wall that requires special procedures for staining, Deinococcus species can be extraordinarily resistant to the effects of gamma rays.

Thermus species

Stain Gram-negative, but have an unusual cell wall. Survive well in high heat, due to their interesting heat-resistant enzymes.

Deinococcus species

Stain Gram-positive, with an odd multilayer cell wall that lets the cells resist high levels of gamma radiation (also due to their extensive DNA repair enzyme activities).

Sulfur and sulfate-reducing bacteria

Sulfur and sulfate-reducing bacteria

Clostridium tetani

Tetanus: a disease characterized by painful muscle spasms.

Members of the genus Mycoplasma have no cell wall, making them somewhat unique in the microbial world. How do they prevent osmotic lysis?

Their cytoplasmic membrane is rich in sterols to help provide added strength and rigidity.

Which is NOT an obligate intracellular parasite?

Treponema pallidum

T/F: All coliforms are Enterobacteriaceae, but not all Enterobacteriaceae are coliforms.

True

T/F: Staphylococcus species can be distinguished from Streptococcus, Enterococcus, and Lactococcus species on the basis of catalase activity.

True