Gram Positive Bacilli

Question 1

Where is Listeria monocytogenes found?

Answer 1

in environment and causes stillbirths and meningitis in a wide range of animals

Question 2

Who does Listeria monocytogenes effect?

Answer 2

in humans, we see infection in neonates, pregnancy, and the immunocompromised; we see it with epidemics associated with foodborne illness

Question 3

How do we test for Listeria monocytogenes?

Answer 3

we can take a specimen, culture, or use molecular detection (such as PCR)

Question 4

Where is Corynebacterium spp. found?

Answer 4

it is found in the environment and normal flora of humans and animals in skin, oral cavity, and genitourinary (GU) tract of humans

Question 5

What are some characteristics of Listeria monocytogenes?

Answer 5

it is an opportunistic pathogen, most often considered contaminants when isolated, it is a gram-positive bacilli that resembles “L” or “V” shapes and may palisade (line up parallel)

Question 6

What is Corynebacterium diphtheriae?

Answer 6

a pathogen that has an exotoxin when infected with a phage that carries the TOX genes - this toxin affects myocardium and peripheral nervous system: death is a result of asphyxiation or myocarditis

Question 7

What disease can Corynebacterium diphtheriae cause?

Answer 7

Diphtheria; pharyngitis with a thick, leathery, gray membrane; fever and malaise

Question 8

How do we test for Corynebacterium diphtheriae?

Answer 8

via specimen, and methods like serology, culture, molecular detection, and toxin production detection (ELEK test or PCR test)

Question 9

How do we treat diphtheria?

Answer 9

diphtheria antitoxin, antibiotics, and supportive therapy

Question 10

Where do we find Corynebacterium jeikeium?

Answer 10

is a part of our normal skin microbiome, and one of the most commonly encountered Corynebacterium in clinical specimens

Question 11

What diseases does Corynebacterium jeikeium cause?

Answer 11

infection in immunocompromised, prosthetic heart valve infection, septicemia, skin infections

Question 12

Where is Nocardia spp. found?

Answer 12

in the environment, it is NOT a part of our normal microbiome; it is also a strict aerobe

Question 13

What does Nocardia look like?

Answer 13

long, slender, gram-positive bacilli that show branching and beading

Question 14

What disease does Nocardia cause?

Answer 14

it is an opportunistic pathogen, it causes bronchopulmonary and cutaneous infections; if it spreads it goes to the central nervous system can causes brain abscesses

Question 15

How do we test for Nocardia?

Answer 15

we take a culture from a specimen

Question 16

What are some characteristics of Gardnerella vaginalis?

Answer 16

there is only 1 species; it is a facultative anaerobe; gram-stain shows gram-variable pleomorphic bacilli; fastidious

Question 17

What disease does Gardnerella vaginalis cause?

Answer 17

bacterial vaginosis; it presents as green, frothy vaginal discharge with a foul odor, we can diagnosis by presence of clue cells

Question 18

How can we test for Gardnerella vaginalis?

Answer 18

we take a specimen and use antigen detection, we can also use a wet prep slide to look for clue cells

Question 19

What are some characteristics of Lactobacillus spp.?

Answer 19

it is a normal flora of the gastrointestinal and genital tracts; decrease in number with bacterial vaginosis; rarely causes disease

Question 20

What are some general characteristics of the Bacillus species?

Answer 20

generally low virulence; found in soil, water, dust, and animal products; common contaminant in lab; produces SPORES; thee gram-stain is large, box-car shaped bacilli that may stain gram-variable, aerobe or facultative anaerobe

Question 21

What is Bacillus anthracis?

Answer 21

the major pathogen of the Bacillus genus

Question 22

What disease can Bacillus anthracis cause?

Answer 22

causes the infection called anthrax in grazing animals; most virulent human pathogen of the Bacillus species and is discussed as an agent used for biological warfare; causes anthrax in humans (pulmonary, cutaneous, and gastrointestinal)

Question 23

What disease does Bacillus cereus cause?

Answer 23

causes food poisoning associated with rice dishes; eye and wound infections (less frequently)

Question 24

How can we test for Bacillus cereus?

Answer 24

take a specimen and use molecular assays for B. anthracis, culture for both B. anthracis and B. cereus

Question 25

What are some characteristics of Clostridium?

Answer 25

gram-stain is large gram-positive bacilli; anaerobes; produce spores

Question 26

Where is Clostridium found?

Answer 26

it inhabits the soil, water, vegetation, large bowel of humans and other animals; many are significant pathogens of livestock and wildlife

Question 27

What are the characteristics of Clostridium perfringens?

Answer 27

it produces many exotoxins and enzymes that divide the organism into 7 types (A-G), with type A being most important to humans; large-box-car shape gram-positive bacilli; growth is rapid; produces high amounts of gas

Question 28

What disease does Clostridium perfringens cause?

Answer 28

gas gangrene, invasion of muscle around a wound site by Clostridium that caused necrosis and gas is produced when the muscle carbohydrates are fermented by the organisms; food poisoning

Question 29

How do we test for Clostridium perfringens?

Answer 29

collect specimen and culture

Question 30

What are the characteristics of Clostridium difficile?

Answer 30

present in bowel of healthy persons or acquired from an exogenous source; antibiotic therapy alters the normal microbiome of the bowl and allows C. difficile to overgrow

Question 31

What disease does Clostridium difficile cause?

Answer 31

produces toxins; bloody diarrhea is a result and may develop a pseudomembrane - pseudomembranous colitis

Question 32

How do we test for Clostridium difficile?

Answer 32

take specimen and use molecular detection, culture with reflex to cytotoxin assay, antigen detection, or immunosorbent assay (ELISA) for C. diff toxin and or C. diff organism

Question 33

How can we identify C. diff without needing to test?

Answer 33

colonies smell like horse manure; in a culture the colonies have a “ground glass” apperance

Question 34

What is the potential treatment?

Answer 34

we may be able to use stool transplant to treat it

Question 35

What are characteristics of Clostridium tetani?

Answer 35

spores enter the body through wounds; then germinate to vegetative cells; in soil, dust, human and animal excrement; produces toxin is conditions right and travels to CNS

Question 36

What disease does Clostridium tentani cause?

Answer 36

tetanus - blocks muscle relaxation muscles contract at the same time; diagnosis is clinical

Question 37

How do we treat tetanus?

Answer 37

1) neutralize circulating toxin with antitoxin
2) relieve muscle spasms
3) keep airways open
4) remove infected tissue and treat with penicillin
5) tetanus toxoid booster shot

Question 38

Where is Clostridium botulinum found?

Answer 38

spores are in soil, water, and on surface of fresh vegetables

Question 39

What diseases does Clostridium botulinum cause?

Answer 39

food botulism - associated with inadequate processing of canned foods, toxin is inactivated by sufficient cooking (100 C for 10 min.); wound botulism; infant - organism introduced into baby’s system in honey and other dietary supplements; botulism causes muscles to not contact making the persons flaccid

Question 40

How can we test for Clostridium botulinum?

Answer 40

usually performed by public health departments

Question 41

How can we treat Clostridium botulinum?

Answer 41

penicillin and high dose horse antitoxin; supprotive measures