Micro Exam 4 GP Anaerobes/GP Rods

Clostridium, actinomyces, peptostreptococcus, cutibacterium, and lactobacillus

What are the 5 GP anaerobes?

Rod, large, spore

Clostridium spp. are GP, ____-shaped and typically (small/large) in size. They are ____-forming.

Obligate, volatile, putrid

Clostridium spp. are (facultative/obligate) anaerobes. They produce a variety of ____ fatty acids and gases (H2, CO2, NH3) giving cultures a (fruity/putrid) odor.

Decaying, endospores, reservoirs, yes, intestines

Clostridium spp. are widely distributed in soil, sediment, and ____ organic matter. ____ persist in the environment for long periods, acting as infection ____.Are they part of the normal microbiota in humans and animals? If yes, where are they found.

Exotoxins, toxin-mediated mechanisms, endogenous, exogenous

Pathogenic Clostridium spp. produce potent (endotoxins/exotoxins) that are among the most powerful known to humans. Are diseases a result of toxin-mediated mechanisms or direct bacterial invasion? Infections are typically ____ (intestinal overgrowth) or ____ (environmental contamination of wounds or food).

Clostridioides difficile

What is now the most common nosocomial infection with 430,000 confirmed cases in US hospitals and LTCF?

Antimicrobials, MDR, binary toxin, elderly, alcohol, soap, water, PCR

Clostridioides difficile infection increasing incidence:

1. Overuse of ____ in general and secondary to ____ organisms

2. Emergence of more fit and capable strains with virulence factors like ____ ____

3. Growing ____ population (LTCF)

4. Promotion of ____ based waterless hand sanitizers because C. diff is resistant to it - washing hands with ____ and ____ is better

5. Use of ____ technology - increased rate of detection

Toxin A and Toxin B

What are the main virulence factors of Clostridioides difficile?

Enterotoxin, cytotoxin, -, +

Toxin A is also known as (cytotoxin/enterotoxin) and Toxin B is also known as (cytotoxin/enterotoxin). Majority of C. difficile strains are Toxin A(+/-)/B(+/-).

Pathogenicity locus

Clostridioides difficile also has ____ ____ as a virulence factor. These are certain regulatory genes that produce toxins and determine in an infection will be pathogenic.

Epidemic, binary toxin

BI/NAP1/027 Clostridioides difficile is an ____ strain that produces 16-32 times more Toxin A and B. Almost all produce ____ ____, and ABX resistance patterns are different.

Acute, diarrhea, leukocytosis, colonic

Clostridioides difficile clinical presentation includes (acute/chronic) onset, watery ____ (possibly > 10/day), (leukopenia/leukocytosis), and abdominal cramping. Complications or extensive disease can cause ____ damage.

ABX exposure, PPI

What is the single most important risk factor of C. difficile? In addition to this, ____ exposure is a risk factor because it suppresses gastric acid secretion, allowing bacteria that normally don't grow in acidic environments to grow.

Clindamycin, cephalosporins, fluoroquinolones, carbapenems, and penicillins

What 5 ABX classes have a high risk of causing C. difficile?

Clindamycin

What ABX historically had the greatest association with CDAD (C. diff associated diarrhea) but overall use has decreased?

Suspicion, lab, sensitive, toxin

Diagnostic tools of C. difficile relies on clinical ____ and ____ testing. To diagnose C. difficile, you typically use highly (sensitive/specific) test like GDH antigen or PCR AND confirmatory ____ test.

Active infection, colonization

If C. difficile PCR, GDH, and toxin test come back positive, what does that mean? What if toxin test is negative?

Unexplained, 3, unformed, episode

C. difficile diagnostics should only be submitted on patients with ____ and new onset >/= ____ unformed stools in 24 hours. Only test (formed/unformed) stools. Do not perform repeat testing (within 7 days) during same ____ of diarrhea.

Isolation, contact, bleach, rectal, soap, water, abx

C. difficile infection control measures:

1. Patient ____ in single room, preferably with bathroom

2. Strict ____ precautions

3. Terminal room cleansing with 1:10 ____

4. Avoidance of ____ thermometers

5. ____ + ____ for hand washing, not hand sanitizer

6. ____ stewardship and control

Botulinum neurotoxin (BoNT), flaccid paralysis

Clostridium botulinum produces the ____ ____, one of the most potent toxins known. This toxin causes severe ____ ____ in humans.

Cans, spores, toxin, spores, honey, flora, GI, injections

Clostridium botulinum exposure routes:

1. Foodborne from damaged ____

2. Wound - ____ contaminated wound and produce ____ in tissue itself

3. Infant - ____ ingested and germinate in immature gut, often from ____

4. Adult infectious - similar to infant but from disrupted gut ____ or underlying ____ abnormality

5. Inadvertent from contaminated _____

A, B, E, F

Clostridium botulinum - botulism toxin:

What toxin is implicated in foodborne and wound botulism?

What toxin is implicated in foodborne, wound, and infant botulism?

What toxin is implicated in fish and marine products?

What toxin is rare but can cause severe botulism?

C, D, G

What three botulism toxins are rarely if ever implicated in human infection?

Transcytosis, epithelial, tight junctions, absorption

Botulism toxin enters cell through ____. Then it disrupts ____ barrier. Toxin A and B disrupt the ____ ____ while Toxin C directly damages the epithelial cells. This facilitates ____ into the body.

Neuromuscular, excitatory, flaccid paralysis

Botulinum neurotoxin reaches nerve terminals at the ____ junction. It acts to block (excitatory/inhibitory) synaptic transmission, resulting in ____ ____.

Internalization, translocation, neurotransmitter

Three steps of Clostridium botulinum neurotoxin:

1. ____ (endocytosis)

2. Disulfide reduction and ____

3. Inhibition of ____ release - inhibits ACh

Heat, racket

Clostridium tetani is ____ stable and ubiquitous in environment. It is ____ shaped.

Tetanospasmin, respiratory, spasms, facial, umbilical stumps

Four types of tetanus:

1. Generalized - ____ is the active toxin, arched back, lock jaw, dangerous when affects ____ muscles

2. Localized - least common, painful ____ limited to near the wound site

3. Cephalic - rare and mainly affects ____ cranial nerve

4. Neonatal - from contaminated ____ ____

7, lymphatic, lock jaw, respiratory/cv system affects

Average incubation period for generalized tetanus is ____ days. Toxins disseminate via ____ and vascular system. What is the first sx which then progresses to neck/back? What is typically the reason for death?

Motor, CNS, axon, is not, spastic

Tetanus neurotoxin is different from the botulinum toxin because it only uses ____ neurons and targets neurons in the ____. It typically uses ____ transport as primary mode. It (is/is not) absorbed through GI tract - direct inoculation of wounds. It causes (flaccid/spastic) paralysis.

Foodborne, gastroenteritis, gas gangrene, necrosis

One of Clostridium perfringens most common manifestations is ____ illness after ingestion of meats that sit warm for a long time. It causes ____ that is usually self-limiting. It also causes ____ ____ characterized by gas on imaging, purulence, fetid odor, and significant ____.

Alpha toxin

What is Clostridium perfringens key toxin?

Bacilli, thin, branching, fastidious

Actinomyces spp. are anaerobic, GP ____. They are typically (thin/thick) and ____, but may be short and club-shaped. They are (fastidious/non-fastidious) bacteria and prolonged incubation may be necessary before lab confirmation.

Mouth, gut, genital tract, mixed

Where are Actinomyces spp. normal flora of? They are typically in (single/mixed) infections.

Lesion, fibrosis, fibrosis, sulfur

Actinomyces spp. has a characteristic chronic ____. It is a mass of draining sinus tracts with dense ____ "woody hard". It has "____ granules" which are aggregates of bacteria.

Slowly, tumor, Nocardia

Actinomycosis lesions expand (quickly/slowly) without limitation to anatomical boundaries. Lesions are often mistaken for a ____. The main differential is ____ due to similar appearance on Gram stain and presentation.

Lumpy jaw, fever, lung, ruptured, intrauterine

Actinomyces spp. most common presentation is cervicofacial "____ ____" (swollen, erythematosus process in jaw area). Thoracic presentation is mild ____, cough, and purulent sputum. ____ tissue may be destroyed. Abdominal presentation often follows ____ appendix or ulcer. Genital presentation is rare and results from colonization of an ____ device.

Cocci, non-spore forming

Peptostreptococcus is an anaerobic, GP ____ that may be seen in short chains and pairs. They are (spore forming/non-spore forming).

Skin, oral cavity, upper respiratory tract, GI and GU tract

Peptostreptococcus is part of the normal microbiota of which parts of the body (5)?

Polymicrobial, abcesses

Peptostreptococcus is most often in (monomicrobial/polymicrobial) infections. They are associated with ____ in oral cavity or CNS.

Bacilli, non-spore forming, propionic acid, slow, 14

Cutibacterium is an anaerobic, GP ____. It is (spore forming/non-spore forming) and its metabolic products include ____ ____. Highly pleomorphic. (Slow/fast) growing and may take up to ____ days to recover clinically significant isolates.

Oral, large

Cutibacterium is normal microbiome of skin, ____ cavity, (small/large) intestine, conjunctiva, and external ear canal.

Acnes vulgaris, prosthetic, lipase and inflammation

Cutibacterium acnes is associated with ____ ____ and can also cause postsurgical wound infections, particularly from ____ devices. Hard to determine if it's a pathogen or contaminant. What is the key toxin/feature?

Facultative, rods, non-spore forming, GI, vagina

Lactobacillus are (facultative/obligate) anaerobic, GP ____. They are (spore-forming/non-spore forming). It is found naturally in the human microbiota in the oral cavity, ____ tract, and ____.

Gut, probiotics, fermentation, opportunistic

Lactobacillus contributes to ____ health by competing with pathogens and modulating immune system. Used as ____ in foods and supplements. It is involved in the ____ of foods. Usually beneficial and non-pathogenic, but can cause ____ infections (bacteremia or endocarditis in IC or critically ill).

Corynebacterium, Streptomyces, Bacillus, Listeria monocytogenes, and Nocardia

What are the 5 GP aerobic rods?

+, nonmotile, club, V, skin

Corynebacterium spp. are aerobic/facultative anaerobic GP, catalase (+/-), oxidase variable rods. They are non-spore forming, (motile/non-motile) bacteria. They are ____-shaped that can form ____ shaped due to incomplete separation during replication. Medically relevant species exist as ____ flora.

Skin, soft tissue, bloodstream, biofilm, contaminant

Corynebacterium spp. most common presentation is cutaneous ____/____ ____ infections resulting from breakdown/trauma. Can also cause ____ infection, most commonly from C. jeikeium and C. striatum that produce ____ (CLABSI). Since it is a normal skin flora, have to confirm it is a true infection not just ____.

Beta-lactamase, C. striatum, exotoxin, necrosis, C. diphtheriae

Corynebacterium spp. virulence includes varied antibiotic resistance. Most carry ____-____ gene (bla). Which species is associated with daptomycin resistance. Virulence also includes phospholipase D (endotoxin/exotoxin) that causes ____/tissue damage in SSTI. Which species is associated with Diphtheria exotoxin?

Skin, device, polymicrobial, acquired

Corynebacterium striatum typical habitat is normal ____ flora and hospital environments/device colonization.

Clinical syndromes include ____-related infections, bacteremia, and endocarditis.

Patient population is (monomicrobial/polymicrobial) infections, hospitalized or device-bearing patients.

Have (acquired/intrinsic) MDR.

Skin, moist, bacteremia, monomicrobial, intrinsic

Corynebacterium jeikeium typical habitat is normal ____ flora but more restricted to ____ areas often in hospitalized patients.

Clinical syndromes include ____, endocarditis, device/prosthetic infections, and cellulitis.

Patient population is (monomicrobial/polymicrobial) infections in IC or neutropenic patients.

Have (acquired/intrinsic) MDR.

Toxin, toxigenicity

Diphtheria is an acute, bacterial disease caused by ____-producing strains of C. diphtheriae. No matter what type of C. diphtheriae, all isolates should be tested for ____.

Respiratory droplets, skin, vaccination, endemic

Diphtheria is transmitted via ____ ____/exposure to infect ____ lesions. Risk factor includes lack of ____ (children and young adults at higher risk), travel to ____ areas, and IC status.

Nasopharynx, culture/microscopy, Elek

Diphtheria is acquired in the ____ and can produce toxins that inhibit cellular protein synthesis, destroy local tissue, and form pseudomembrane. Testing is done with standard ____/____ or PCR. Toxin testing is done through the ____ test that looks for precipitate formation from interaction with antitoxin.

Pharynx, tonsils, 2-5

Diphtheria clinical presentation is classified based on respiratory vs. non-respiratory. Most common sites are respiratory ____ and ____. Incubation is ____-____ days.

Actinomyces, +, +, obligate, filamentous

Streptomyces spp. is a genus within the ____ group. They are GP, catalase (+/-), oxidase (+/-), and (facultative/obligate) aerobes. They are spore forming, non-motile, and non-acid-fast. They are ____, branching hyphae.

Metabolites, secondary, earthy, spores

Streptomyces spp. can exist in plants and produce ____. They produce unique (primary/secondary) that have antibacterial, antifungal, antiviral, and antitumoral activity. These metabolites are responsible for the ____ odor that attracts insects to them which them spread ____.

Actinomycetoma, Madura foot

Streptomyces spp. can rarely cause infections. One of the most common is an ____ which is a chronic, granulomatous disease of skin and SQ tissue. It is classically called "____ ____" - mycetoma of lower extremities.

Phytotoxins, biofilm

Streptomyces spp. can have virulence factors in plants - ____ that cause scab disease in plants. Virulence factors in humans include adherence factors and ____ production.

+, rods, obligate, facultative, Bacillus anthracis

Bacillus spp. are GP, catalase (+/-), oxidase variable, spore forming, motile ____. The genus includes both (facultative/obligate) aerobes and (facultative/obligate) anaerobes. What is the only non-motile species?

GI tract and skin

Bacillus spp. are ubiquitous in the environment, including being found in hospitals, food, and humans where?

Fried rice, systemic, anthracis

Bacillus cereus can cause food poisoning, also known as ____ ____ syndrome that has a diarrheal and emetic form. Bacillus cereus uncommonly can also cause ____ infection but is mostly seen in IC hosts. Bacillus ____ causes Anthrax with a prodromal phase and advanced stage.

Emetic toxins, capsule, toxin

Bacillus cereus virulence includes heat-stable ____ ____ responsible for emetic food poisoning. Bacillus anthracis virulence includes a protein ____ and three component ____.

Animals, cutaneous, painless, inhalation, dissemination, GI

Anthrax transmission is through infected ____ and their products. Most common and safest presentation is ____, causing itchy, small blisters or bumps with significant swelling. This leads to a (painful/painless) sore. The most rare and deadly presentation is through ____ of the spores. This leads to ____ throughout the body. Can also present as a ____ syndrome after eating raw/undercooked meat.

Bacillus anthracis

What agent is used in bioterorrism?

Spore, persistence, germination, fatal

Anthrax life cycle:

1. ____ formation

2. Environmental ____ - spores remain dormant for years

3. ____/multiplication

4. Disease progression - can be ____

Culture, toxin, biopsy, lesion

Anthrax diagnosis:

1. Classic ____/Gram stain

2. PCR that identifies anthrax lethal factor ____

3. Tissue ____ - skin or lung

4. ____ swabs

Yes

Does anthrax have a vaccine?

B. anthracis, B. anthracis, B. cereus, both

B. anthracis vs. B. cereus:

Which is nonmotile?

Which has a capsule?

Which one causes food poisoning?

Which one is spore forming?

Facultative, +, -, rods, will not, culture/microscopy, multiplex

Listeria monocytogenes are GP (facultative/obligate) anaerobes. They are catalase (+/-), oxidase (+/-), non spore forming, motile ____. Motility is temperature dependent so it (will/will not) move in the human body. Diagnostic is through ____/____ and is available on ____ PCR.

Listeriosis, GI, meningitis

Listeria monocytogenes clinical presentations include ____ (invasive disease), ____ infection, and ____ in extremes of age (CNS).

Survival, vacuoles

Listeria monocytogenes virulence includes ____ in monocytes, macrophages, and neutrophils. It also escapes ____ with potent enzymes and proteins.

Actinobacteria, Corynebacteriales, +, -, obligate, acid-fast, filaments, IC

Nocardia spp. is in class ____ and order ____. They are GP, catalase (+/-), oxidase (+/-) bacilli. They are (facultative/obligate) aerobes. They are weakly ____-____ (stains irregularly). It is branching ____. It infects ____ hosts.

Pulmonary, cavitary, CNS, cutaneous

The most common clinical syndrome (in IC hosts) of Nocardia spp. is ____ infection. It enters directly into pulmonary cavity. Chronic infection causes ____ lesion, pleural effusions, and extrapulmonary abscesses with ____ involvement. Less commonly can cause ____ infection characterized by red, firm, painful nodules or ulcerations with purulence.

Superoxide dismutase, acid-fast, culture

Nocardia spp. virulence is from ____ ____ that neutralizes ROS produced by immune cells and allows bacteria to survive in host phagocytes. Diagnosis is done through ____-____ stain and ____/susceptibility.