Bacilli

Question 1

What’s a spore?

Answer 1

Released by certain bacteria when it sense it’s in danger.
Gives it the ability to survive in different environment.
Metabolically inactive.
when it senses it’s safe: comes out of vegetative state and release potent exotoxins = diseases

Question 2

Name (6) spore forming gram + bacilli

Answer 2

Bacillus anthracis
Bacillus cereus
Clostridium botulinum
Clostridium tetani
Clostridium perfringens
Clostridium difficile

Question 3

Bacillys anthracis characteristics (5)

Answer 3

Unique protein capsule (antiphagotic)
Aerobic
Spores very stable to heat, drying, UV and disinfectants
Used in bio-terrorism and warfare

Question 4

Bacillus anthracis exotoxins

Answer 4

Encoded on pXO1 plasmid: optimally increased @37C, increased CO2 (respiratory tract)
pXO2 plasmid encodes genes: both plasmid necessary for virulence
3 seperate proteins: edema factor (EF), protective antigen (PA) lethal factor (LF): separate are not toxic but together yes

Question 5

Bacillus anthracis: disease

Answer 5

Anthrax

Question 6

B. anthracis treatment

Answer 6

Antibiotics (penicillin)

Vaccine available for Protective antigen (PA) protein

Question 7

B. cereus characteristics (2)

Answer 7

Motile

non encapsulated

Question 8

B. cereus: disease (2 types of enterotoxins)

Answer 8

causes food poisoning with enterotoxins
heat labile: nausea, abdominal pain, diarrhea (12-24h)
heat stable: severe N/V (short incubation)

Question 9

B. cereus treatment

Answer 9

penecillin resistant (antibiotic treatment are useless)

Question 10

C. botulinum characteristics (2)

Answer 10

found in smoked fish or improperly canned vegetables

botox: paralyse to get rid of wrinkles or excessive sweating

Question 11

C. botulinum (disease) (2)

Answer 11

rapid fatal food poisoning: lethal neurotoxin blocks Ach release in autonomis system: flaccid muscle paralysis
afebrile, bilateral cranial nerve palsies, double vision, trouble swallowing, muscle weakness, deadly if gets to respiratory tract

infant botulism (honey): spores germinates and bacteria colonize colon: constipation, trouble swallowing muscle weakness

Question 12

C. botulinum treatment

Answer 12

antitoxin and respiratory assistance if needed

Question 13

C. tetani disease

Answer 13

tetanus (rusty nail contaminated with spores)
exotoxin: tetanospasmin
substained severe contraction of skeletal muscles
severe muscle spasms (lock jaw) high mortality rate (heart stays contracted)

Question 14

C. tetani (treatment)

Answer 14

Booster (inactivated toxoid) every 10 years

Question 15

C. perfringens disease (2 classes)

Answer 15

gas gangrene:

1. wound infection/cellulitis: necrotic skin exposed to bacteria, damage to local tissue (skin moist, spongy with crackly pockets)
2. clostridial myonecrosis: bacteria inoculated into muscle, exotoxin secretion destroys adjacent muscles (when degrade: black fluid excreted from skin) (fatal if not treated)

Question 16

C. perfringens treatment (clostridial myonecrosis)

Answer 16

oxygen
antibiotics (penicillin)
removal of damaged tissue

Question 17

C. difficile characteristics (2)

Answer 17

1. more common in hospitals than tetanus, anthrax or botulism
2. overuse of broad-spectrum antibiotics destroys normal intestinal flora (get it once, more chance of getting it again)

Question 18

C. difficile disease

Answer 18

Antibiotic-associated pseudomembranous colitis
infected colon release toxin:
toxin A: diarrhea
toxin B: cytotoxic to colon cells

severe diarrhea, abdominal cramping, fever

Question 19

C. difficile treatment

Answer 19

discontinue antibiotic treatment to allow normal flora back

administer metronidazole or vancomycin

Question 20

Clostridium bacterias characteristics

Answer 20

anaerobics (different from bacillus)
powerful exotoxins (rapid diagnosis possible)

Question 21

Non spore forming rods (2)

Answer 21

Listeria monocytogenes

Corynebacterium diphteriae

Question 22

L. monocytogenes charateristics (4)

Answer 22

1. food: soft cheese, unpasteurized milk, cold cuts, pâté
2. psychrophile (survives in refrigerator)
3. facultative intracellular aerobe
4. can pass 3 protective barriers (blood-brain, GI, feto-placental)

Question 23

L. monocytogenes disease

Answer 23

listeriosis: general malaise, diarrhea, meningitis, speticeamia, still-birth/abortion
high mortality rate

Question 24

L. monocytogenes treatment

Answer 24

antibiotics

no vaccines

Question 25

C. diphteriae disease

Answer 25

diphteria: colonization of pharynx and release in the blood stream exotoxins damages heart and neural cells

Question 26

C. diphteria treatment

Answer 26

antitoxin, penicillin, DTP vaccine | can be lysogenized by bacteriophage

Question 27

4 groups of enteric gram - bacilli

Answer 27

Enterobacteriaceae: salmonella, shigella, E. coli Vibrionaceae: Vibro, campylobacter Pseudemonadaceae: pseudonomas Bacteriaidaceae

Question 28

Classification of enterics

Answer 28

``` Biochemical classification (nutritional needs) lactose fermentation (EMB: dark purple/black, MacConkey: pink) ``` surface antigen variable O antigen (outermost layer of LPS): changes between enteric K-antigen: covers the O-antigen H-antigen: flagellar sub-unit (only in motile bacteria)

Question 29

Diseases caused by enterics (4 categories)

Answer 29

1. diarrhea with/without systemic invasion binds to intestinal cell but do not enter exotoxin release: diarrhea, enterotoxin: fluid/electrolyte loss watery diarrhea, no fever vibrio cholera 2. diarrrhea with intestinal cell invasion binding and invasion of cells bloody stools, fever response shigella 3. diarrhea with invasion of lymph nodes and bloodstream AP, diarrhea containing white and red blood cells, fever headache, increased white and red blood cell counts salmonella typhi, Yersinia enterocolitica, campylobacter jejeuni 4. other enterics intecions UTI, pneumonie, bacteremia, sepsis nosocomial infections by E. coli, etc.

Question 30

Salmonellea characteristics (3)

Answer 30

enterobacteriaceae unable to ferment lactose all in animal reservoirs except S. enterice serovar typhi (human host only)

Question 31

Salmonellea type (5) + characteristics

Answer 31

1. S. enterica serovar enteritidis: enterocolitis, min 10^5, incubation time 6-48h, contamined food (poultry, eggs, meat) or person to person Typhymurium: human host Typhi: typhoid fever, contaminated products (milk, milk product, contaminated water, shellfish, food handling Paratyphi: parathyphoid fever (milder) S. bongori

Question 32

Salmonella diseases

Answer 32

enterocolitis: N/V, profus diarrhea, AP, fever, chills, headach, myalgia (2-3 recovery), speticemia (rare) enteric fever: generalized infection (bacterial multiplication in lymphoid nodes), necrosis of intestinal tissue (ulcer, hemorrhage, perforation)

Question 33

Salmonella treatment/diagnosis

Answer 33

use stool for culture diagnosis (isolation from blood 1st week, or urine/stool 2-3rd weeks) vaccine available but only effective on small bacteria load antibiotic not recommended (kill normal flora)

Question 34

E. coli characteristics (3)

Answer 34

most numerous aerobic bacteria of normal gut flora lactose fermenting pathogenic to other parts of the body (opportunistic)

Question 35

Diseases E coli

Answer 35

Bacteriuria Gastroenteritis neonate meningitis and nosocomial urinary and wound infection

Question 36

E coli gastroenteritis types (4)

Answer 36

Enterotoxigenic E coli: infant diarrhea, traveller's diarrhea, enterotoxins Enteroinvasice E. coli: similar to shigellosis Enteropathogenic E. coli: older name for serotypes causing infant diarrhea E. coli O157: H7: haemorrhagic colitis, hamburger disease

Question 37

Shigellae characteristic, prevention, treatment

Answer 37

non-lactose fermenter seen in children, poor sanitation and crowding prevention: safe food handling, clean water, safe disposal of sewage no vaccine

Question 38

Shigellae disease

Answer 38

acute diarrhea with mucus, pus and blood shigella sonnei (europe and north america) S. dysenteriae: tropics, severe illness (watery diarrhea, cramps, fevers) infection from small number of organisms

Question 39

vibrio cholerae characteristics and disease

Answer 39

South-east asia, Africa mainly water-borne cholera: GI illness: profuse water diarrhea, cramps, fever enterotoxin binds to cells intestin: cells secrete chloride, absorb less Na: water accumulates in intestine= watery diarrhea (10-15 L/day) = dehydration

Question 40

Campylobacter (2 types, disease)

Answer 40

C. jejuni C. coli Normal flora of birds and domestic animals some strains invasive, some toxigenic causes human enteritis (number one cause of gastroentritis): fever, AP, bloody diarrhea maybe on cause of traveller's diarrhea

Question 41

Pseudonomas (general + 2 types)

Answer 41

General: opportunisitic pathogen, found in moist habitat and water (eg: humidifiers), resistant to many antibiotics P. aeruginosa: respiratory pathogen in CF patients, infection in lesions of burn patients P. cepacia: common contaminant of saline solution and water, able to multiply in low nutrient environments: respiratory pathogen in CF patient

Question 42

Haemophilus influenzae

Answer 42

part of normal nasopharyngeal flora in many adults and children invasive infection of young children (meningitis, pneumonia, joint infections) increased bronchial inflammation in pts already having chronic bronchitis vaccine available

Question 43

Enterobacter spp.

Answer 43

nosocomial infection, wound infection, pneumonia, bacteremia | E. sakazakii linked to infant illness from powdered infant formula

Question 44

H. pylori

Answer 44

microaerophilic, spiral bacilli urease: protection from low pH causes stomach ulcers triple therapy treatment: antibiotics and H+ pump inhibitors

Question 45

Bordetella pertussis (4 virulence factors)

Answer 45

1. pertussis toxin 2. extra cyytoplasmic adenylate cyclase (weakens host defense) 3. filamentous hemagglutinin: bronchial attachment and release 4. tracheal cytotoxin: destroys ciliated cells: poor clearance of mucus and bacteria whooping cough vaccine with heat killed organisms

Question 46

Legionella pneumophila

Answer 46

opportunistic pathogen grows in water, shower head transmission: aerosols causes legionnaires disease may cause severe pneumonia