Anaerobic bacteria

Question 1

C tetani are what? How can it be introduced?

Answer 1

environmental, gram positive, and spore-forming; Think soil contamination of wounds like splinters, IV drugs, septic surgery, thorns

Question 2

C tetani releases what? What are the four types of disease?

Answer 2

Exotoxin tetanospasmin;

1. neonatal
2. cephalic
3. local
4. generalized

Question 3

Neonatal tetanus involves

Answer 3

contamination of umbilical cord and lack of materal immunization

Question 4

Cephalic and local tetanus

Answer 4

both have low mortality so long as they remain local

Question 5

In generalized tetanus, what happens to the exotoxin? What can lead to >50% untreated mortality?

Answer 5

It ENTERS THE BLOODSTREAM;

respiratory failure

Question 6

In C tetani, the two subunits are

Answer 6

B and A, with B delivering A to end of motor neuron and A moves retrograde to CNS

Question 7

The A subunit acts as what?

Answer 7

a protease, cleaving synaptobrevin in inhibitory motor nerves of the CNS

Question 8

On C tetani exam, what are some hallmark features? Test that can demonstrate C tetani?

Answer 8

1. Local rigidity, difficulty swallowing
2. Strong muscle spasms/paralysis
3. Trismus (lockjaw)
4. Grimace (risus sardonicus)
5. Look for the STRONG ARCHING OF THE BACK!;
   Spatula test: they bite down

Question 9

Lab tests for C tetani include:

Answer 9

1. Microscopy with tennis racket appearance

2. Bloodwork can confirm vaccination and rule out STRYCHNINE POISONING

Question 10

For C tetani treatment, this includes

Answer 10

tetanus antitoxin to neutralize the toxin;
could use antibiotics like metronidazole, but wound often clear on presentation;
maybe benzo!!

Question 11

Prevention of C tetani includes

Answer 11

vaccination, with tetanus toxoid, while adults get boosters every 10 years; unvaccinated adults can get vaccine at any time

Question 12

C botulinum is a; presents as; most common sources of C botulinum?

Answer 12

gram +, spore-forming, environmental bacteria; foodborne botulism;
alkaline vegetables like home-canned beans or if the spores survive inadequate sterilization of pre-prepped foods

Question 13

C bot: Germinating cells infected by ____ phage release what?

Answer 13

lysogenic; botulinum toxins, with A and B being most common

Question 14

For C botulinum, what happens to germinating bacteria and the bot exotoxin? How do bot and tetani differ once they arrive at a neuromuscular junction?

Answer 14

The germinating bacteria typically die;

bot tetani will stay in periphery and affect ACh release!!

Question 15

A consequence of Bot pathogenesis is

Answer 15

flaccid paralysis and could affect respiratory system

Question 16

Two less common presentations of Bot include

Answer 16

Infant botulism (kid is floppy and has uncooked honey) and wound botulism (wound contaminated in IV drug user)

Question 17

On exam for bot, you would see in foodborne botulism

Answer 17

descending weakness and paralysis, and patient has history of suspect foods

Question 18

For treatment of C botulinum what are you worried about? What is needed in wound botulism?

Answer 18

Horse-sourced antitoxin can inactivate toxin in bloodstream, which could lead to SERUM SICKNESS;
debride and high-dose IV penicillin

Question 19

How to prevent C botulinum?

Answer 19

Cook adequately, sterilize the canned foods and vacuum-packed foods, and discard swollen cans!!

Question 20

What can botulinum toxin A be useful for?

Answer 20

Cosmetics and blepharospasm (eyelid), writer’s cramp, anal fissures and torticollis

Question 21

C perfigrens is a

Answer 21

gram pos spore-forming rod that can lead to necrotizing fasciitis/myonecrosis

Question 22

How does C perfringens enter? What can be seen on histology?

Answer 22

Serious wounds like war, car accident, septic abortion, where you disrupt blood flow;
Gas production!!!

Question 23

C perfrigens can produce

Answer 23

alpha toxin with enzymes that break down tissue

Question 24

On exam, C perfringens can show

Answer 24

1. Bronze skin color, then blue-black
2. maybe develops at site of malignancy
3. could see crepitation and tachy
4. Then ARDS, renal failure, shock!!

Question 25

In C perfringens, what do you see on radiography, and what is needed to confirm myonecrosis?

Answer 25

Feathering pattern of gas in soft tissue; | SURGICAL EXPLORATION FIRST!!

Question 26

To treat C perfrigens and prevent it?

Answer 26

Can give antibiotics like penicillin G and clindamycin, or clindamycin with metronidazole; clean and debride the wounds!!

Question 27

In C perfringens, besides gas gangrene, what can happen?

Answer 27

Food poisoning: inadqueate cooking fails to kill the bacteria and the spores grow up

Question 28

For C perfringens poisoning, what area is affected?

Answer 28

Type A enterotoxin can destroy tight junctions between epi cells in gut

Question 29

Tests, treatment and prevention for C perfringens food poisoning?

Answer 29

None required; DON'T STOP THE DIARRHEA; | Thorough cooking!!

Question 30

C difficile is a ____ that causes what? How can it emerge?

Answer 30

Gram positive, spore-forming rod; pseudomembranous colitis; | fecal-oral or can come up in normal gut flora and spike in hospitalized pop (maybe antibiotic use)

Question 31

What two toxins of C diff can cause issues?

Answer 31

Exotoxin A: disrupts tight junctions and causes intestinal swelling and inflammation Exotoxin B: MAJOR TOXIN, disrupting cytoskeleton by depolymerizing acting, killing surrounding cells

Question 32

On C diff exam, what could be seen?

Answer 32

Nonbloody cramping diarrhea; antibiotic use, chemo, or immunsuppressants in history; patches of dead cells on sigmoidoscopy, maybe toxic megaolon or colonic perforation

Question 33

Treatment of C diff?

Answer 33

1. Withdraw initial antibiotics 2. Unless disease is very mild, give oral metronidazole or vanco 3. LET TOXINS FLUSH 4. Maybe removal/surgical resection of colon

Question 34

Bacteroides and prevotella are

Answer 34

gram-negative bacilli that are NON-SPORE forming; these guys are opportunistic pathogens that are in normal flora of mucous membranes

Question 35

Treatment of B and P complicated by

Answer 35

1. slow growth (potential antibiotic resistance) | 2. polymicrobial, so if one secretes beta-lactamase, whole abscess/colony protected from penicillin!!

Question 36

Abscesses for B and P start off as ___ which use up the O2, followed by?

Answer 36

Facultative anaerobes; anaerobes

Question 37

Diagnosis of B and P includes in the history:

Answer 37

Painful abscess that could move to meningitis (neck)

Question 38

B and P are usually found

Answer 38

below the diaphragm if B, above if P

Question 39

B and P can be diagnozed lab-wise via

Answer 39

needle aspiration (bypass normal flora and maintain anaerobic condition); MAKE SURE YOU CULTURE ON ANAEROBIC BLOOD AGAR; identify by sugar fermentation and gas chromatograpohy

Question 40

Treatment and prevention of B and P includes

Answer 40

metronidazole primarily, and combine with aminoglycides to kills facultatives in abcesses, REQUIRES SURGICAL CARE; perioperative cephalosporin

Question 41

Actinomyces are

Answer 41

gram+ filmaentous rods, non spore-forming; anaerobitc to microaerophilic and normal flora of mouth, vag

Question 42

Actinomyces pathology includes

Answer 42

bacteria escaping proper compartment during trauma; non-comm, with good prognosis

Question 43

Presentations of actinomyces include:

Answer 43

1. Head/neck: pus drainage and hard, non-tender swelling in face, neck, chest; history of dental work, poor dental hygiene 2. Abdomen: slow-growing tumor and usually diagnozed on EXPLORATORY SURGERY

Question 44

For actinomyces: you'll see on lab; treatment could include

Answer 44

branching Gram+ rods with sulfur granules; can be anaerobically cultured; penicillin G with possible surgical drainage

Question 45

SS: Anaerobic infections usually follow

Answer 45

deep-tissue trauma: accidents, cancer, surgery, immunosuppression, IV drug use

Question 46

SS: For what is there a vaccine available?

Answer 46

ONLY TETANUS

Question 47

SS: All of the anaerobes here are? What is gram pos and neg?

Answer 47

RODS; | Clostridia and actinomyces are gram pos, B and P are gram neg

Question 48

SS: of the bacteria in this lecture, which are environmental, normal flora, both?

Answer 48

Environmental: C tetani, botulinum; normal: C difficile, B and P, and actinomyces; Both: C perfringens

Question 49

SS: C tetani and botulinum produce

Answer 49

neurotoxins with same protease activity butopposite clinical effects because of nerves affected: tetanospasmin inhibitor CNS leads to spasms, botulinum toxin stimulatory on periphery, leading to flaccid paralysis

Question 50

SS: Diagnosis of C tetani and botulinum includes; infection is usually; how do you treat? who is affected?

Answer 50

exam; the infection is usually transiet; treatment is primarily with ANTITOXIN to bind and inactivate neurotoxin; you would see this in neonates, IV drug users, infected wounds, botulism in contaminated food

Question 51

SS: C perfringes in gas gangrene, B and P produce; how do you identify and treat? What's special about gas gangrene?

Answer 51

tissue-degrading enzymes; identify by anaerobic culture and gas chromatography, treat with antibiotics plus surgical care; resolved ASAP: lethal exotoxemia

Question 52

SS: C perfringens in food poisoning produces

Answer 52

enterotoxin: symptomatic treatment

Question 53

SS: C difficile causes ____ after what? How to treat?

Answer 53

pseudomembranous colitis; antibiotic use; | often nosocomial, change antibiotic and intervene SURGICALLY as necessary

Question 54

SS: Actinomyces produces ____ containing what? Where is it found and how do you treat?

Answer 54

nodules; pus with sulfur granules; | mouth or colon and treat with penicillin with surgical care as necessary