Gram Positive Rods I and II: Bacillus, Nocardia, Actinomyces, Corynebacterium, Listeria

***Bacillus 1. Gram + or -? 2. Shape 3. Aerobic/Anaerobic? 4. Spores/No spores? 5. Does it produce toxins? 6. Only bacteria with a x capsule

BACILLUS I. General Microbiology A. Gram-positive rods B. Aerobic C. Sporeformers D. Produce toxins E. Only bacteria with a protein capsule

***Bacillus anthracis Toxins 1. 3 Proteins assemble into # distinct toxin molecules 2. These two toxin molecules are called ? toxins 3. The A component - is it toxic? Is it active? What does it do? What can't it do? 4. The B component - is it toxic? Is it active? What does it do? What can't it do? --------- There are 3 anthrax toxin components 5. Protective antigen (PA) is the x component. Antibodies to this antigen will neutralize toxins how? 6. Lethal Factor (LF) consists of one x component. What type of enzyme is it? What does it do? What key protein does it cleave? What are the results of this? LF can also induce secretion of x from macrophages 7. Edema Factor (EF) - is the other x component). What type of enzyme is it? When delivered into the cell, what does it do? How does it cause edema? PA + LF = x toxin PA + EF = x toxin

Bacillus anthracis Toxins 1. Three proteins assemble into 2 distinct toxin molecules. 2. These are A-B toxins. 3,4. The A (Active) component is toxic, possessing enzymatic activity which damages some critical metabolic component of the cell. The A component cannot bind to, or enter the cell, however, without the B (Binding) component, which has no toxic activity itself, but binds the toxin to a cell surface receptor, and delivers the A component into the cell. The 3 anthrax toxin components are: 5. Protective antigen (PA), the B component. Antibodies to protective antigen neutralize the toxins by preventing their attachment to the cell - thus the name "protective antigen" 6. Lethal Factor (LF), one A component. This molecule is a zinc- metalloproteinase that binds to, and cleaves, an essential intracellular signaling enzyme, mitogen-activated protein (MAP) kinase, leading to cell death. It also induces secretion of pro- inflammatory cytokines (TNF-α and IL-1β from macrophages. 7. Edema Factor (EF), the other A component. LF is an adenylate cyclase which, when delivered into the cell produces elevated intracellular cAMP, causing fluid and electrolyte loss (and thus tissue edema). PA + LF = lethal toxin PA + EF = edema toxin

Two most important Bacillus species from a medical viewpoint

Bacillus anthracis and Bacillus cereus

What is a mycetoma?

painless, chronic subcutaneous infection with draining sinus tracts

T/F - Nocardia can cause brain abscesses

true

*****Bacillus anthracis Pathogenesis and Disease State Card 1 1. Anthrax is a xsis - a disease acquired mostly from animals or animal products. 2. Anthrax spores can be found on the xs and in the xs of herd animals, and in x where they have grazed. 3. Humans can be infected by contact with animals or soil containing the xs. 4. Transmission from animals is rare in the US because of high x rates in herd animal populations. 5. Because spores are so hardy and hard to kill and because inhalation anthrax has such high mortality and a rapid course, weaponized (xed) spores that can easily be inhaled are a potent agent of biological warfare. 6. Symptoms are mainly the result of the actions of the xs.

*****Bacillus anthracis Pathogenesis and Disease State 1. Anthrax is a zoonosis - a disease acquired mostly from animals or animal products. 2. Anthrax spores can be found on the hides and in the intestines of herd animals, and in ground where they have grazed. 3. Humans can be infected by contact with animals or soil containing the spores. 4. Transmission from animals is rare in the US because of high vaccination rates in herd animal populations. 5. Because spores are so hardy and hard to kill and because inhalation anthrax has such high mortality and a rapid course, weaponized (disaggregated) spores that can easily be inhaled are a potent agent of biological warfare. 6. Symptoms are mainly the result of the actions of the toxins

*****Bacillus anthracis Pathogenesis and Disease State Card 2 Clinical manifestations: Anthrax can be acquired by 3 routes; through broken skin (cutaneous anthrax) through ingestion of spores (gastrointestinal anthrax) or through the aerosol route (inhalation anthrax). a. Cutaneous anthrax (the most common type) begins as a x at the site of inoculation, which progresses to an x and then to an enlarging x (necrosis) with surrounding tissue edema and lymphadenopathy. Symptoms can become systemic, with about a #% mortality rate if untreated. b. Gastrointestinal anthrax (very rare in the US) begins as an x at the site of invasion, progressing to regional lymphadenopathy, edema, and sepsis, with a x mortality rate. c. Inhalation anthrax is the most dangerous type, characterized by initial x-like symptoms and xal lymphadenopathy, followed soon after by edema, sepsis, shock, xal signs (in about 50% of cases), and a mortality rate of about #%. The preferred treatment is xin, but it must be given very soon after the initial signs to save the patient.

2. Clinical manifestations: Anthrax can be acquired by 3 routes; through broken skin (cutaneous anthrax) through ingestion of spores (gastrointestinal anthrax) or through the aerosol route (inhalation anthrax). a. Cutaneous anthrax (the most common type) begins as a papule at the site of inoculation, which progresses to an ulcer and then to an enlarging black eschar (necrosis) with surrounding tissue edema and lymphadenopathy. Symptoms can become systemic, with about a 20% mortality rate if untreated. b. Gastrointestinal anthrax (very rare in the US) begins as an ulcer at the site of invasion, progressing to regional lymphadenopathy, edema, and sepsis, with a high mortality rate. c. Inhalation anthrax is the most dangerous type, characterized by initial flu-like symptoms and medaistinal lymphadenopathy, followed soon after by edema, sepsis, shock, meningeal signs (in about 50% of cases), and a mortality rate of about 80%. The preferred treatment is ciprofloxacin, but it must be given very soon after the initial signs to save the patient.

*****Actinomyces 1. Shape 2. Spore forming? 3. Gram positive or negative? 4. Aerobic or anaerobic? What other bacteria can be distinguished from Actinomyces based on this result? 5. Acid fast staining? What other bacteria can be distinguished from Actinomyces based on this result? 6. Actinomyces causes granules of x in tissues 7. Part of normal flora where? Male/female?

ACTINOMYCES Specific Microbiology a. Filamentous non-spore-forming gram positive rods b. Anaerobic - compare this to Nocardia, which is exclusively aerobic. c. NON-acid fast, compare this to Nocardia, another filamentous bacteria which is partial acid fast. d. Sulfur granules in tissues e. Found as normal flora in the female genital tract, respiratory tract, and intestine, so infection is usually endogeneous, from one's own flora.

*****Bacillus cereus - Virulence factors and disease state Bacillus cereus produces 2 toxins involved in causing x toxin and x toxin. 1. Strains associated with rice, particularly, carry an x toxin. This heat stable, protease resistant toxin is preformed on the food, and when ingested, causes nausea, vomiting, and abdominal cramps. Because it is preformed, it acts quickly, causing symptoms 1-6 hours after ingestion, with a quick resolution (8-10 hours). There is no fever. 2. Strains associated with meat or vegetables produce a x toxin, which is heat labile. This toxin is not preformed on the food, but produced by the bacteria after ingestion, so the onset is later (18-24 hours). It is characterized by nausea, abdominal cramps, and watery diarrhea. Its mechanism of action is similar to enterotoxigenic E. coli, with adenylate cyclase-activating activity.

Bacillus cereus produces 2 toxins involved in causing gastroenteritis emetic toxin and diarrheal toxin. 1. Strains associated with rice, particularly, carry an emetic toxin. This heat stable, protease resistant toxin is preformed on the food, and when ingested, causes nausea, vomiting, and abdominal cramps. Because it is preformed, it acts quickly, causing symptoms 1-6 hours after ingestion, with a quick resolution (8-10 hours). There is no fever. 2. Strains associated with meat or vegetables produce a diarrheal toxin, which is heat labile. This toxin is not preformed on the food, but produced by the bacteria after ingestion, so the onset is later (18-24 hours). It is characterized by nausea, abdominal cramps, and watery diarrhea. Its mechanism of action is similar to enterotoxigenic E. coli, with adenylate cyclase-activating activity.

***Bacillus cereus produces 2 toxins involved in causing gastroenteritis emetic toxin and diarrheal toxin. 1. Strains associated with x, particularly, carry an emetic toxin. - Is this toxin heat stable? - Is this toxin susceptible to proteases? - What happens when ingested? - Why does it act really quickly? - How long does infection/resolution usually take? - Do you get a fever with this? 2. Strains associated with x or x produce a diarrheal toxin - Is this toxin sensitive to heat? - Is this toxin preformed on the food? - When does this toxin get made? - What are major symptoms of infection? - Its mechanism of action is similar to enterotoxigenic x, with xase-activating activity.

Bacillus cereus produces 2 toxins involved in causing gastroenteritis emetic toxin and diarrheal toxin. 1. Strains associated with rice, particularly, carry an emetic toxin. This heat stable, protease resistant toxin is preformed on the food, and when ingested, causes nausea, vomiting, and abdominal cramps. Because it is preformed, it acts quickly, causing symptoms 1-6 hours after ingestion, with a quick resolution (8-10 hours). There is no fever. 2. Strains associated with meat or vegetables produce a diarrheal toxin, which is heat labile. This toxin is not preformed on the food, but produced by the bacteria after ingestion, so the onset is later (18-24 hours). It is characterized by nausea, abdominal cramps, and watery diarrhea. Its mechanism of action is similar to enterotoxigenic E. coli, with adenylate cyclase-activating activity.

Bacillus anthracis Specific Microbiology 1. Large or small gram positive rods? 2. Are rods isolated or paired? 3. This structure is required for pathogenicity. 4. The protein capsule is composed of what modified amino acid? 5. Function of protein capsule? 6. When do spores form? 7. Are spores metabolically active? Do they replicate? 8. Are spores resistant to drying? Heat? Cold?

Bacillusanthracis A. Specific Microbiology 1,2. Large gram positive rods in pairs or long chains 3,4,5. Protein (poly-D-glutamate) capsule is required for pathogenicity (anti-phagocytic) 6. Spores form when growth conditions become less favorable. 7,8. Spores are metabolically inactive and do not replicate, but are highly resistant to drying, and extremes of heat or cold. Spores allow the bacteria to survive for many years until favorable growth conditions return.

*****Corynebacterium diphtheriae 1. Name of the organism is a Greek byproduct of describing this feature 2. Diphtheria means what? 3. Corynebacterium grows on these two media types 4. Three main species of Corynebacterium 5. Is the bacteria invasive? How does it actually cause harm? What must happen before the bacteria can really cause any harm? 6. Describe the effects of the Corynebacterium exotoxin on the heart, nerves, kidneys. What does the exotoxin inhibit? 7. Areas of necrosis have this, which itself can cause suffocation 8. Treat infection with x primarily, with secondary xn or xn. 9. Patients with this should be kept xed. 10. How to prevent? What concentration of vaccine is effective? 11. T/F - Humans are the only hosts.

Corynebacterium diphtheriae 1,2. Name of the organism refers to the Greek "korynee" or club for the club shaped gram- positive organism. Diphtheria means leather hide, referring to the appearance of the leathery membrane which is typical of this infection. 3. Grows on Loeffler's or potassium tellurite media. 4. Three species: gravis, intermedius, and mitis. 5,6,7. Not an invasive organism. Stays superficial on mucus membranes skin. If the organism harbors a lysogenic Beta phage, it produces a powerful exotoxin. The toxin inhibits protein synthesis and primarily affects the heart (myocarditis), nerves (demyelination), and kidneys (tubular necrosis). The local necrosis produces a pseudomembrane, which itself can cause suffocation. 8,9. Treatment is with Diphtheria antitoxin (DAT) and erythromycin or penicillin. Patients should be isolated. 10. Prevention is with vaccination. Concentrations of 0.1-0.01 International Units is protective. 11. Humans are the only hosts.

Bacillus anthracis prevention and diagnosis 1. Is a vaccine available? For animals? Humans? 2. Diagnose anthrax via x. 3. T/F - Spores are a common pathological finding

D. Prevention. A vaccine is available for animals, and works well. It is also given to humans in high risk occupations, but is less effective than for animals. E. Diagnosis. a. Culture b. Observation of gram positive rods in clinical specimens (spores are rarely seen in clinical samples.

Listeriolysin O - function?

Damages the phagosome membrane, virulence factor of Listeria monocytogenes

*****Nocardia Disease states 2 a. Bronchopulmonary disease caused by x of the pathogen from the environment - usually occurs in xed patients with reduced T cell function - slowly x with cavitary lesions. Nocardia can disseminate to the CNS, causing brain xes. b. x or x lesions can occur due to traumatic implantation, even in people with normal immune systems. A mycetoma is a painless, chronic subcutaneous infection with x sinus tracts.

Disease states a. Bronchopulmonary disease caused by inhalation of the pathogen from the environment - usually occurs in immunocompromised patients with reduced T cell function - slowly progressive with cavitary lesions. Nocardia can disseminate to the CNS, causing brain abscesses. b. Cutaneous or lymphocutaneous lesions can occur due to traumatic implantation, even in people with normal immune systems. A mycetoma is a painless, chronic subcutaneous infection with draining sinus tracts.

*****Nocardia disease states Disease states a. x disease caused by inhalation of the pathogen from the environment - usually occurs in immunocompromised patients with reduced x cell function - xly progressive with xary lesions. Nocardia can disseminate to the x, causing x abscesses. b. Cutaneous or lymphocutaneous lesions can occur due to x xtation, even in people with normal immune systems. A x-oma is a painless, chronic subcutaneous infection with draining sinus tracts.

Disease states a. Bronchopulmonary disease caused by inhalation of the pathogen from the environment - usually occurs in immunocompromised patients with reduced T cell function - slowly progressive with cavitary lesions. Nocardia can disseminate to the CNS, causing brain abscesses. b. Cutaneous or lymphocutaneous lesions can occur due to traumatic implantation, even in people with normal immune systems. A mycetoma is a painless, chronic subcutaneous infection with draining sinus tracts.

*****Actinomyces Disease states a. produce suppurative granulomatous lesions that form xs connected by sinus tracts. - What are the sulfur granules? Texture and color? Since they are found as normal flora in the mouth and vagina, the filamentous rods can invade from those sites causing b. Cervicofacial ("lumpy jaw") actinomycosis - - Constant or progressive? - Occurs in patients with poor x. c. Pelvic Actinomycosis, with x abscesses or ureteral xtion and extensive tissue damage.

Disease states a. produce suppurative granulomatous lesions that form abscesses connected by sinus tracts. Hard, yellow microcolonies called sulfur granules are seen in tissues, and can drain to the outside. Since they are found as normal flora in the mouth and vagina, the filamentous rods can invade from those sites causing b. Cervicofacial ("lumpy jaw") actinomycosis - slowly progressive, but destructive, occurring in patients with poor dental hygiene (bad periodontal disease) and c. Pelvic Actinomycosis, with tubal-ovarian abscesses or ureteral obstruction and extensive tissue damage.

*****Actinomyces disease states 1. Disease states a. produce xive xous lesions that form abscesses connected by x. Hard, yellow microcolonies called xs are seen in tissues, and can drain to the outside. Since they are found as normal flora in the mouth and vagina, the filamentous rods can invade from those sites causing b. xcosis - slowly progressive, but destructive, occurring in patients with poor dental hygiene (bad periodontal disease) and c. xcosis, with tubal-ovarian abscesses or ureteral obstruction and extensive tissue damage.

Disease states a. produce suppurative granulomatous lesions that form abscesses connected by sinus tracts. Hard, yellow microcolonies called sulfur granules are seen in tissues, and can drain to the outside. Since they are found as normal flora in the mouth and vagina, the filamentous rods can invade from those sites causing b. Cervicofacial ("lumpy jaw") actinomycosis - slowly progressive, but destructive, occurring in patients with poor dental hygiene (bad periodontal disease) and c. Pelvic Actinomycosis, with tubal-ovarian abscesses or ureteral obstruction and extensive tissue damage.

What happens in cervicofacial actinomycosis?

Disease states a. produce suppurative granulomatous lesions that form abscesses connected by sinus tracts. Hard, yellow microcolonies called sulfur granules are seen in tissues, and can drain to the outside. Since they are found as normal flora in the mouth and vagina, the filamentous rods can invade from those sites causing b. Cervicofacial ("lumpy jaw") actinomycosis - slowly progressive, but destructive, occurring in patients with poor dental hygiene (bad periodontal disease) and c. Pelvic Actinomycosis, with tubal-ovarian abscesses or ureteral obstruction and extensive tissue damage.

What happens in pelvic actinomycosis?

Disease states a. produce suppurative granulomatous lesions that form abscesses connected by sinus tracts. Hard, yellow microcolonies called sulfur granules are seen in tissues, and can drain to the outside. Since they are found as normal flora in the mouth and vagina, the filamentous rods can invade from those sites causing b. Cervicofacial ("lumpy jaw") actinomycosis - slowly progressive, but destructive, occurring in patients with poor dental hygiene (bad periodontal disease) and c. Pelvic Actinomycosis, with tubal-ovarian abscesses or ureteral obstruction and extensive tissue damage.

What must happen in order for Corynebacterium diphtheriae to produce exotoxin?

Not an invasive organism. Stays superficial on mucus membranes skin. If the organism harbors a lysogenic Beta phage, it produces a powerful exotoxin. The toxin inhibits protein synthesis and primarily affects the heart (myocarditis), nerves (demyelination), and kidneys (tubular necrosis). The local necrosis produces a pseudomembrane, which itself can cause suffocation.

*****Listeria monocytogenes 1. Shape 2. Gram positive or negative? 3. Spores or no spores? 4. Aerobic or Anaerobic? 5. What type of hemolysis on blood agar? What could you confuse this bacteria with? 6. CAMP test positive or negative? What is the CAMP test? 7. Motile or non-motile? 8. Major virulence factor 9. Where do you see this bacteria usually? 10. Listeria are important pathogens in these susceptible individuals 11. Main syndromes of Listeria infection are xitis and xis

Listeria monocytogenes 1,2,3,4. A coccobacillus that is gram positive, non-sporulating and aerobic. 5,6. Produces a narrow ring of Beta-hemolysis on sheep's blood agar (may be confused with Group B strep). It also produces a positive CAMP test. 7. Motile-examples are the "umbrella pattern" of growth at room temperature and "tumbling motility" microscopically. 8. Virulence factors include listeriolysin O which damages the phagosome membrane. 9. Widely distributed in foods/animals 10. Important pathogens in neonates, pregnancy, & in patients with defects in cell mediated immunity. 11. Main syndromes are meningitis & sepsis

Actinomyces produces suppurative granulomatous lesions that form abscesses connected by sinus tracts. 1. What are the two main areas of infection and what diseases correlate with those areas?

Mouth - cervicofacial actinomycosis Vagina - Pelvic actinomycosis.

*****Nocardia Specific Microbiology 1. Shape 2. Gram positive or negative? 3. aerobe or anaerobe? 4. Urease positive or negative? 5. Catalase positive or negative? 6. What does it mean that they are partially acid fast? 7. What are the two main disease states one can get from this bacteria? 8. How would these disease states initiate?

NOCARDIA 1. Specific Microbiology a. Filamentous non-spore-forming gram positive rods b. Strict aerobes c. Partially acid fast - contain mycolic acids in cell wall d. Urease positive e. Catalase positive Disease states a. Bronchopulmonary disease caused by inhalation of the pathogen from the environment - usually occurs in immunocompromised patients with reduced T cell function - slowly progressive with cavitary lesions. Nocardia can disseminate to the CNS, causing brain abscesses. b. Cutaneous or lymphocutaneous lesions can occur due to traumatic implantation, even in people with normal immune systems. A mycetoma is a painless, chronic subcutaneous infection with draining sinus tracts.

Other Corynebacterium and Related Organisms. A. Arcanobacterium hemolyticum - xitis and a xiform rash. B. Corynebacterium jeikeium - associated with bacteremic disease in x patients. The organism is unusually drug resistant--susceptible only to xin. C. Rhodococcus equi-associated with xary xia in patients with defects in x mediated immunity (such as AIDS). x staining.

Other Corynebacterium and Related Organisms. A. Arcanobacterium hemolyticum - pharyngitis and a scarletiniform rash. B. Corynebacterium jeikeium - associated with bacteremic disease in cancer patients. The organism is unusually drug resistant--susceptible only to vancomycin. C. Rhodococcus equi-associated with cavitary pneumonia in patients with defects in cell mediated immunity (such as AIDS). Acid fast staining.

Other Corynebacterium and Related Organisms. A. xbacterium xicum- pharyngitis and a scarletiniform rash. B. xbacterium xium - associated with bacteremic disease in cancer patients. The organism is unusually drug resistant--susceptible only to vancomycin. C. xcoccus x-associated with cavitary pneumonia in patients with defects in cell mediated immunity (such as AIDS). Acid fast staining.

Other Corynebacterium and Related Organisms. A. Arcanobacterium hemolyticum - pharyngitis and a scarletiniform rash. B. Corynebacterium jeikeium - associated with bacteremic disease in cancer patients. The organism is unusually drug resistant--susceptible only to vancomycin. C. Rhodococcus equi-associated with cavitary pneumonia in patients with defects in cell mediated immunity (such as AIDS). Acid fast staining.

Bacillus cereus Treatment/Prevention - treatment is supportive (xion). Prevention - Will boiling rice kill the bacterial spores? - Spores will germinate when rice is held warm, but at too x a temperature to kill the bacteria. As they grow on the rice, they produce the x toxin. Food must either be kept x, to prevent growth, or kept at a x enough temperature to kill the vegetative bacterial cells when they try to grow. .

Treatment/Prevention - treatment is supportive (rehydration). Prevention - boiling rice will not kill the bacterial spores. They will germinate when rice is held warm, but at too low a temperature to kill the bacteria. As they grow on the rice, they produce the emetic toxin. Food must either be kept cold, to prevent growth, or kept at a high enough temperature to kill the vegetative bacterial cells when they try to grow.

*****Bacillus anthracis Pathogenesis and Disease State Card 2 Clinical manifestations: Anthrax can be acquired by 3 routes; through broken skin (X anthrax) through ingestion of spores (X anthrax) or through the aerosol route (X anthrax). 1. Which is the most common type of anthrax? 2. Which is the deadliest type of anthrax? 3. Which begins as a papule at the site of inoculation, which progresses to an ulcer and then to an enlarging black eschar (necrosis) with surrounding tissue edema and lymphadenopathy. Symptoms can become systemic, with about a 20% mortality rate if untreated. 4. Which begins as an ulcer at the site of invasion, progressing to regional lymphadenopathy, edema, and sepsis, with a high mortality rate. 5. Which is characterized by initial flu-like symptoms and medaistinal lymphadenopathy, followed soon after by edema, sepsis, shock, meningeal signs (in about 50% of cases), and a mortality rate of about 80%. The preferred treatment is ciprofloxacin, but it must be given very soon after the initial signs to save the patient.

cutaneous through broken skin, gastrointestinal via spore ingestion, inhalation via aerosol route 1. Most common is cutaneous anthrax 2. Deadliest is inhalation anthrax 3. Cutaneous anthrax 4. Gastrointestinal anthrax 5. Inhalation anthrax