CH 19 SMARTBOOK: Gram Positive Rods of Medical Importanc

Select all that apply What is used to subdivide the gram-positive bacilli into three general groups? - Cardinal temperatures - Shape of the cells - Acid-fast staining properties - Layers in the cell wall - Presence of endospores

- Acid-fast staining properties - Presence of endospores

Select all that apply What is used to subdivide the gram-positive bacilli into three general groups? - Layers in the cell wall - Cardinal temperatures - Presence of endospores - Shape of the cells - Acid-fast staining properties

- Acid-fast staining properties - Presence of endospores The gram-positive bacilli can be subdivided into three general groups based on the presence or absence of endospores and the characteristic of acid-fastness. Further levels of separation correspond to oxygen requirements & cell morphology.

Which genus contains members that cause actinomycosis? - Actinomyces - Mycobacterium - Aspergillus - Nocardia

- Actinomyces

Which genus contains members that cause actinomycosis? - Aspergillus - Actinomyces - Mycobacterium - Nocardia

- Actinomyces

Which term refers to a group of nonmotile, filamentous rods that may be acid-fast and are closely related to Mycobacterium? - Propionibacterium - Actinomycetes - Nontuberculosis Mycobacteria - Corynebacterium

- Actinomycetes

The major source for infection with L. monocytogenes is _________. - infected animals - contaminated soils - contaminated foods - infected humans

- contaminated foods

M. tuberculosis is a long, thin, rod that grows in strands called ________ which appear red with ______ stain. - hyphae, gram - filaments, acid-fast - cords, acid-fast - cords, gram

- cords, acid-fast

An IGRA test, such as the T-SPOT TB test, determines whether in individual has been exposed to tuberculosis by detecting ______________. - gamma interferon release from presensitized lymphocytes - the presence of anti-tuberculin antibodies - complement fixation - increased phagocytic activity

- gamma interferon release from presensitized lymphocytes

Genus Clostridium

- gram-positive - spore-forming - anaerobic & catalase-negative habitats: - saprobic members are frequently found in soil, sewage, vegetation, & organic debris - commensals inhabit the bodies of humans & other animals - infections caused by pathogenic species are not normally communicable but occur when spores are introduced into injured skin

The gram-positive bacilli can be subdivided into ________ general groups based on the presence or absence of ____________ and the characteristic of acid-fastness.

3 endospores

Acid-fast staining is used to diagnose infections by which group of organisms? - Clostridium - Mycobacterium - Nocardia - Bacillus

Mycobacterium

The three genera in the irregular non-spore-forming bacilli group with the greatest clinical significance include ___________, ___________, and __________.

Mycobacterium Nocardia Corynebacterium

Which of the following characteristics can be used to differentiate between the genera Bacillus and Clostridium? - Endospore formation - Cell morphology - Gram stain reaction - Oxygen requirements

Oxygen requirements

Which of the following characteristics can be used to differentiate between the genera Bacillus and Clostridium? Oxygen requirements Gram stain reaction Endospore formation Cell morphology

Oxygen requirements

What color will acid-fast organisms show in the Ziehl-Neelsen acid-fast staining procedure? - Green - Red - Purple - Blue

Red

Select all that apply Which are the genera in the irregular non-spore-forming bacilli group with the greatest clinical significance? - Listeria - Mycobacterium - Nocardia - Corynebacterium - Bacillus

These tend to be pleomorphic and tend to stain unevenly. - Mycobacterium - Nocardia - Corynebacterium REASONING: - Listeria - Listeria species are regular, non-spore forming bacilli. - Bacillus - Bacillus species are spore-forming bacilli.

T/F Nocardia infections are mostly reported in patients that are immunocompromised.

True

When infected tissue is stained in a special way and observed under the microscope, Mycobacterium tuberculosis appears as a grouping of massed filaments called _________ that are red in color due to __________-fast staining.

cords acid

An infection by Mycobacterium marinum has been labeled ____________ _______________ granuloma because the disease is strongly associated with work around aquariums.

fish tank

An in vitro test for detecting tuberculosis infection involves incubating blood with synthetic M. tuberculosis proteins. Any lymphocytes with prior sensitivity to the tuberculoproproteins will release interferon ___________, which is measured by machine.

gamma

Animal handlers can minimize their risk of erysipeloid by wearing protective ____________.

gloves

Most botulism outbreaks occur in ____________ -processed foods, including canned vegetables, smoked meats and cheese spreads.

home

The causative agent for Hansen's disease is __________ leprae.

mycobacterium

The pathogen causing gas gangrene is Clostridium ____________, , the pathogen causing botulism is Clostridium _____________, , and the pathogen causing tetanus is Clostridium ____________.

perfringens botulinum tetani

Members of the genus Clostridium are gram- __________ spore-forming ____________.

positive rods

In the Ziehl-Neelsen acid-fast staining procedure, acid-fast organisms appear bright _______ against a(n) ____________ background.

red blue stain sputum

Nocardia is a genus of bacteria found widely distributed in the ____________ and can cause infection in immunosuppressed hosts.

soil

Select all that apply Most endospore-forming bacteria are members of which two genera? - Corynebacterium - Clostridium - Mycobacterium - Actinomyces - Bacillus

- Clostridium - Bacillus a) Colonies of Bacillus anthracis are large and flat, with a ground glass appearance. The cells form streptobacilli and develop a centrally placed endospore. b) Colonies of Clostridium botulinum are irregular and opaque, surrounded by a shiny margin that comes from the degredation of lipids in the media. Endospores are formed at one end of the cell (terminally) giving the developing sporangia a tennis racquet-shaped morphology

Select all that apply Which of the following are pathogens belonging to the genus Clostridium? - perfringens - tetani - difficile - botulinum - monocytogenes

- Clostridium perfringens (gas gangrene, food poisoning mild) - Clostridium tetani (tetanus) - Clostridium botulinum (botulism) Reason: - difficile: The organism known as "C. diff" has been placed in the genus Clostridiodes.

Select all that apply Which of the following are the main food-borne sources of listeriosis? - Contaminated meat - Contaminated poultry - Contaminated vegetables - Contaminated dairy products

- Contaminated meat - Contaminated poultry - Contaminated dairy products

Select all that apply Which of the following are the predominant pathogens among the regular non-spore-forming Gram-positive bacilli? - Erysipelothrix rhusiopathiae - Clostridium tetani - Lactobacillus species - Listeria monocytogenes

- Erysipelothrix rhusiopathiae - Listeria monocytogenes

Select all that apply Which of the following are characteristics of Bacillus anthracis? - Small gram-negative bacillus - Endospore former - Large gram-positive bacillus - Non-endospore former - Facultative anaerobe - Obligate aerobe - Degrades complex macromolecules

- Facultative anaerobe - Endospore former - Large gram-positive bacillus - Degrades complex macromolecules Largest of all bacterial pathogens & is block-shaped, angular nonmotile rods 3 to 5 nanometers long & 1 to 1.2 nanometers wide, develop central spores under all growth conditions except in the living body of host

Select all that apply Select three correct descriptions of Bacillus anthracis, the causative organism of anthrax. - Restricted to Africa - Gram positive - Spirillum shaped - Forms endospores - Nonmotile rod

- Forms endospores - Gram positive - Nonmotile rod

Select all that apply Select three correct descriptions of Bacillus anthracis, the causative organism of anthrax. - Nonmotile rod - Forms endospores - Gram positive - Restricted to Africa - Spirillum shaped

- Gram positive - Forms endospores - Nonmotile rod

Select all that apply Which of the following describe the characteristics of Clostridium? - Cocci - Gram positive - Catalase positive - Catalase negative - Rods - Gram negative

- Gram positive - Rods - Catalase negative - Spore-forming - anaerobic - not normally communicable but occur when spores are introduced into broken skin

Which poses the highest risk for botulism? - Home-processed foods - Acidified foods - Commercially canned foods - Frozen foods

- Home-processed foods

Select all that apply Which of the following are correct about Propionibacterium acnes? - It is a strict pathogen involved in causing acne. - It is a member of normal microflora of humans. - It is found on human skin and the upper respiratory tract.

- It is a member of normal microflora of humans. - It is found on human skin and the upper respiratory tract.

Which of the following is a regular non-spore-forming Gram-positive bacillus pathogen? - Listeria monocytogenes - Clostridium tetani - Lactobacillus species

- Listeria monocytogenes REASONING: - Clostridium tetani - Clostridium tetani are spore-forming pathogens. - Lactobacillus species - Lactobacillus spp. only rarely act as pathogens.

Select all that apply Which of the following are the predominant pathogens among the regular non-spore-forming Gram-positive bacilli? - Lactobacillus species - Listeria monocytogenes - Clostridium tetani - Erysipelothrix rhusiopathiae

- Listeria monocytogenes - Erysipelothrix rhusiopathiae

Acid-fast staining is used to diagnose infections by which group of organisms? - Nocardia - Bacillus - Clostridium - Mycobacterium

- Mycobacterium

Which is the causative agent of Hansen's disease? - Mycobacterium tuberculosis - Corynebacterium diphtheriae - Mycobacterium bovis - Mycobacterium leprae - Listeria monocytogenes

- Mycobacterium leprae Hansen's disease (leprosy) is a chronic, progressive disease of the skin and nerves known for its extensive medical and cultural ramifications.

Which organism is the cause of fish tank granuloma occurring in those who work around aquariums? - Mycobacterium avium - Mycobacterium bovis - Mycobacterium marinum - Mycobacterium kansasii

- Mycobacterium marinum

Unlike most pathogens, which bacterium does not produce exotoxins or enzymes that contribute to virulence, instead relying on waxes and a cord factor to evade the immune system? - Salmonella typhi - Mycobacterium tuberculosis - Bacillus anthracis

- Mycobacterium tuberculosis

Select all that apply Which of the following characteristics can differentiate between the genera Bacillus and Clostridium? - Gram stain reaction - Presence of catalase - Cell morphology - Oxygen requirements

- Presence of catalase - Oxygen requirements

How are clostridial infections acquired? - They are spread via an aerosol route from humans. - They are spread via an aerosol route from animals. - They are communicable between humans. - They are acquired through contamination of injured skin.

- They are acquired through contamination of injured skin.

A(n) _______ is an immunoglobulin that blocks or neutralizes the action of a specific toxin. - antitoxin - antibiotic - antifungal - antiviral

- antitoxin

Select all that apply Which of the following are pathogens belonging to the genus Clostridium? - botulinum - perfringens - tetani - monocytogenes - difficile

- botulinum - perfringens - tetani Reason: - Monocytogenes is a form of Listeria not a form of Clostridium. - difficile - The organism known as "C. diff" has been placed in the genus Clostridiodes.

Genus Clostridiodes

- gram-positive bacilli - present singly or in short change - endospores are subterminal and distend the cell, altering it's shape - strict anaerobe - cause epithelial necrosis of colon - fecal microbiota transplants (not FDA approved) Until recently, Clostridioides difficile was grouped with the Clostridium, but sequencing of ribosomal RNA showed that the species is distinct enough to warrent placement in a newly created genus.

Propionibacterium acnes is a __________. - member of the normal biota - major cause of acne lesions in the elderly - strict pathogen causing cutaneous and systemic disease

- member of the normal biota

Genus Bacillus

- mostly saprobic bacteria (feeds on dead/decaying organic matter) - aerobic - catalase-positive (produce bubbles) - able to degrade complex macromolecules - common source of antibiotics - found in soil (spores are found in water via dust, bodies of plants/animals) - B. anthracis (cause of anthrax) - B. cereus (cause of one type of food poisoning)

A preventive measure for curtailing the spread of Erysipelothrix rhusiopathiae is to vaccinate ________. - humans - pigs and humans - pigs

- pigs

The circulation of microbial "poisons" in the blood is called ________. - septicemia - toxemia - viremia - bacteremia

- toxemia

Actinomycosis is caused by members of the genus _____________.

Actinomyces

Define endospore

An endospore is a dense survival unit that develops in a vegetative cell in response to nutrient deprivation. The extreme resistance to heat, drying, radiation, and chemicals accounts for the survival, longetivity, and ecological niche of spore-formers, and it is also a significant factor in their pathogenicity.

Endospore-forming bacteria that are gram-positive, motile, rod-shaped forms are mostly found in two genera: ____________ and ____________.

Bacillus and Clostridium

What does it mean if a bacteria is catalase positive or catalase negative?

Bacteria that conduct aerobic metabolism (biological reactions that require O2) produce hydrogen peroxide (H2O2) as a toxic byproduct of their metabolism. Toxic hydrogen peroxide can cause intracellular damage, such as damage to DNA, lipids, and proteins. To remove H2O2 and other similar compounds, cells produce enzymes to break them down, such as catalase. A simple test to determine if bacteria produce catalase is to add hydrogen peroxide to bacteria. If catalase is present, the hydrogen peroxide will be broken down into water and oxygen gas, resulting in the production of bubbles (catalase positive). Obligate anaerobe bacterial species (bacteria that must live in an environment without O2 to survive) lack catalase, which is why they cannot survive in an atmosphere containing oxygen.

T/F Like many pathogens, Mycobacterium tuberculosis produces exotoxins that contribute to its virulence.

F Reason: The tubercle bacteria produces no exotoxins or enzymes for infectiousness.

T/F Clostridial infections are usually communicable.

False Reason: These infections occur when spores enter injured skin.

The general type of staining procedure that is used to diagnose the tuberculosis bacterium based upon its cell wall structure is known as the _____________-fast stain.

acid

A group of nonmotile, filamentous, rod-shaped bacteria closely related to Mycobacterium is the ________________.

actinomycetes

A serum globulin that neutralizes a specific toxin is called a(n) ___________.

antitoxin