L5: Enterobacter II

Question 1

1. What tribe is Shigella a part of?
2. Lactose + or -?
3. Indole + or -?
4. Motile?
5. Co2 + or -
6. What is its habitat?

Answer 1

1. Tribe I - Escherichieae
2. Lactose NEGATIVE
   (E.Coli is positive)
3. Indole negative
4. NOT MOTILE
5. CO2 negative
6. Habitat = intestines of humans

Question 2

How does Shigellavary from E.COli in terms of:

1. Lactose fermentation
2. Gas production
3. Motility

Answer 2

1. NON LACTOSE FERMENTER
2. Non gas producer
3. Non - motile

Question 3

SHigella:

1. Transmission via _____
2. 5f’s
3. Highest risk individuals?

Answer 3

1. Person to person via fecal oral route
2. Contaminated WATER, food, flies, fingers, fomites, feces (5f’s)
3. Young children in day care center/nurseries
   - siblings/parents of these children
   - MALE HOMOSEXUALS

Question 4

PATHOGENESIS of Shigella:

1. Virulent strains carry ____ for attachment and entry
2. Enters cells by _____
3. Organism escapes in _____
4. Intracellular _____ (in cytoplasm)
5. _____ drives organism in cytoplasm
   - Organisms enter adjacent cells
6. Shigella phagocytosed into new cell and released into ____
7. Shigella can KILL _____

Answer 4

1. plasmid
2. phagocytic vacuole
3. cytoplasm
4. replication
5. Actin “tail”
6. cytoplasm
7. PHAGOCYTIC MACROPHAGES

Question 5

Shigella infection does not extend where?

Unlike Salmonella, does it require a low or high inocolum?

Answer 5

Lamina propria!

LOW inoculum to cause disease for shigella!

Question 6

What is the major clinical syndrome of shigella?

What are symptoms of this syndrome?

What is tissue invasion limited to?

How long is the incubation period? How long does it last?

Answer 6

1. Bacillary Dysentry
2. Abdominal cramps, tenesmus, pus and BLOOD in stool
3. Tissue invasion limited to EPITHELIAL. cells and SUBMUCOSA

Fecal leukocytes present

4. Incubation 1-3 days lasting 48 hrs.

HUMAN SERVES AS NATURAL HOST

Question 7

Edwardseilla tarda is found in what habitat?

What tribe is this?

Answer 7

1. Cold blooded vertebrates, fresh water, catfish

Tribe II - Edwardsielleae

Genus Edwardsiella

Question 8

What are the clinical symptoms of E. Tarda?
(2)

Is the diarrhea bloody?

What is it often mistaken for? (2)

Answer 8

1. Gastroenteritis
2. Septicemia (rare)

• acute, self-limiting w/ watery diarrhea

Typhoid like illness with BLOODY diarrhea & possible fever, nausea, vomiting, colonic ulcerations & terminal ileum modularity

3. Mistaken for:
   - Salmonellosis
   - IBD (Crohn’s)

Question 9

What is the habitat for Salmonella (Tribe III)?

a) non-typhoid
b) S.typhi

Answer 9

1. INTESTINEs of Lower animals (poultry, cows, pigs, pets) for non-typhoid strains
2. Humans for S. typhi

Question 10

Salmonella:

1. Lactose fermenter?
2. Produces ____ (black)
3. Trasmission via____
4. Found where? (2)
5. Secondary transmission ____

Answer 10

1. NON - LACTOSE fermenter
2. H2S positive
   (grows black colonies on Nekton Agar plates)
3. transmission via Improper food handling
4. Found in humans and livestock
5. Secondary transmission person-to-person***

Question 11

Salmonella is Encapsulated. T/F

Samonella is acid STABILE T/F

Answer 11

1. TRUE
2. FALSE - Salmonella is acid LABILE (think of lemon on salmon = acidic)
3. Need HIGH DOSE to cause infection

Question 12

Almost half of salmonella epidemics are a result of contaminated_____

Answer 12

contaminated poultry and poultry products

• Also associated with reptiles (lizards, snakes, turtles)

Question 13

What are the 5 clinical syndromes of Salmonella?

Answer 13

1. Asymptomatic (carrier state)
2. Febrile Gastroenteritis
3. Enteric fever
4. Septicemia
5. Focal Infections

Question 14

1. The asymptomatic (carrier) state is mostly seen with S. Typhi (T/F)

Answer 14

1. TRUE

- limited with non-S.Typhi

Question 15

What clinical syndrome of salmonella does the following describe:

1. Most common
2. Incubation of 12-48 hours
3. Symptoms: malaise, nausea, sometimes with vomiting, followed by abdominal pain and diarrhea.
4. Self-limited.
5. Duration 3-5 days.

T/F: Not treated with antibiotics

Answer 15

FEBRILE GASTROENTERITIS

TRUE: Do NOT treat with antibiotics.

WHY???

Can destroy normal flora
Create antibiotic resistant Salmonella strain

Question 16

Enteric Fever:

1. ____ is best example
2. Caused by ___ and ____
3. Incubation period?
4. Length of illness?
5. What are the 2 stages of Enteric Fever?
6. What is the only known reservoir of S. Typhi?

Answer 16

BIMODAL DISEASE

1. Typhoid fever
2. S. Tyhphi & S. Paratyphi A & B
3. Incubation 1-2 weeks
4. Length is 4 weeks
   a) fever for 2 weeks (bacteremic stage)

b) GI symptoms for 2 weeks
6. Only known reservoir of S. typhi is man

Question 17

The following describes what syndromes of Salmonela?

1.Osteomyelitis, meningitis, brain abscess, endocarditis *

2. -found in patients with
   underlying leukemia, lymphoma, AIDS, SLE, sickle cell crisis, and alcoholic hepatitis.
   - Found frequently in infections due to S. choleraesuis, S. dublin, and S. oranienburg.
   Relapses are common

Answer 17

1. Focal Infections

2. Septicemia (w.o major GI involvement)

Question 18

Pathogenesis of Gastroenteritis:

1. Salmonella produces
   produces an _____&raquo_space; stimulates rearrangement of plasma cell membrane to form ruffles.
2. Bacteria enter cell by ______
3. Organisms invade what 3 areas?
4. What is the result?

Answer 18

1. adhesin
2. by pinocytosis associated with ruffles
3. Organisms invade large and small bowel and lamina propria
4. Large inflammatory response induced

Question 19

Pathogenesis of Enteric Fever:

1. Bacteria bind to ___ cells
2. Infection KILLS cell, bacteria go to what area of intestine?
3. Organisms invade ____ where they multiply
4. Inhibition of ____ allows organisms to survive intra-cellularly.
5. Bacteria spread from ____ to ___. (bloodstream)
6. What is a major virulence factor causing SEPTIC shock?
7. Immunity is mediated by what?(2)

Answer 19

1. M cells
2. Peyer’s patches
3. macrophages
4. oxidative metabolic burst
5. Peyer’s patches to Blood stream
6. LPS
7. Humoral & Cell mediated
   (T & B cell)

• S. typhi occurs only in humans

Transmission person-to-person

Question 20

The following are clinical presentations of what?

1. Presents with fever, headache, rose spots, constipation
2. Rose spots; pink macules or prupuric lesions
3. Fever; temperature-pulse dissociation

(Refers to relative bradycardia with a pulse rate less than expected at a given body temperature. Associated with specific infections, including intracellular organisms such as salmonella, legionella, and chlamydia)

4. Neuropsychiatric manifestions

Answer 20

Salmonella ENTERIC FEVER

Question 21

What are some complications of Salmonella Enteric Fever?

Answer 21

1. GI bleeding
2. Perforation of ileal ulcers
3. Circulatory collapse
4. Relapse following treatment
5. Long term carriage

Question 22

Salmonella BACTEREMIA
(bimodal disease)

1. Increased risk in what 3 patient groups?
2. Similar clinically to other ___ bacteremia
3. 10% localized ____ infections (examples)
4. HOW IS IT DIAGNOSED?
5. WHAT IS THE TREATMENT???

Answer 22

1.

a) pediatric
b) geriatric
c) AIDS patients

2. gram (-)
3. SUPPURATIVE
4. Positive blood cultures
5. THIRD GENERATION CEPHALOSPORIN

Question 23

What is the treatment for Salmonella BACTEREMIA?

How is it diagnosed?

Answer 23

1. 3rd generation CEPHALOSPORIN

2. Positive blood culture

Question 24

A 50 year old female returned to Chicago from a 3 week trip to Jakarta (Indonesia) and about 5 days later started having flu like symptoms and a low grade fever. On the day prior to admission she had spiking fevers followed by profuse sweating. Stool cultures, ova and parasite exams and urine cultures were all negative. The blood culture collected after a spiking fever episode grew a glucose-fermenting, gram-negative rod that was oxidase negative. Additional testing showed the organism was lactose-negative and H2S positive. What is the likely etiologic agent of this patient’s symptoms?

Shigella
E. coli O157
Malaria (Plasmodium falciparum)
Salmonella typhi
Vibrio cholera

Answer 24

Salmonella typhi

STOOL CULTURE NEGATIVE –> first 2 weeks septic (bactermia)

next 2 weeks = diarrhea
always get BLOOD AND STOOL if not sure in which stage!!!!

Question 25

TEST QUESTION: what sample should be sent to lab if typhoid fever?

Answer 25

BLOOD & STOOL

Question 26

What tribe do the following fall under? 1. C. freundii, C. koseri What habitat are they found in?

Answer 26

TRIBE IV: Citrobactereae Habitat: intestinal tract humans/animals

Question 27

What are the clinical syndromes of Citrobacter infections? (general) -3 1. Specifically of C. Freundii 2. Specifically for C. Koseri

Answer 27

1. a) Nosocomial infections of urinary and respiratory tracts of debilitated, hospitalized patients b) endocarditis and c) hospital acquired bacteremias 2. C. freundii - rare cause of diarrhea 3. C. koseri - rare cause of meningitis and brain abscess in neonates neonatal menigitis: - E.Coli - Citrobacter KOSERI

Question 28

The following species are under which tribe & Genus? K. pneumoniae, K. oxytoca, K. ozaenae, K. rhinoscleromatis What habitat are they found in? (2)

Answer 28

1. Tribe V: Klebsielleae | 2. Intestines & UPPER RESPIRATORY TRACT of humans & animals

Question 29

What is the Klebsiella species responsible for the following clinical syndrome: (2) Primary lobar pneumonia characterized by destructive changes necrosis hemorrhage ("currant jelly" sputum)**** bronchopneumonia bronchitis, accounts for 9% of UTI's and 14% of bacteremias in hospitalized patients

Answer 29

1) K.pneumoniae | 2) K. oxytoca

Question 30

What is the Klebsiella species responsible for the following clinical syndrome: rhinoscleroma chronic granulomatous disease involving mucosa of upper respiratory tract ***

Answer 30

K. rhinoscleromatis

Question 31

What is the Klebsiella species responsible for the following clinical syndrome: atrophic rhinitis (ozena) destruction of mucosa and fetid mucopurulent discharge (nose)

Answer 31

K. Ozaenae

Question 32

What genus of Tribe V Klebsiella do E. aerogenes & E. cloacae fall under?

Answer 32

Genus: ENTEROBACTER Widely distributed in environment & GI tract of humans

Question 33

What are the clinical symptoms of Enterobacter? 1. frequent colonizers of ____ 2. cause ______ involving urinary tract, respiratory tract, cutaneous wounds 3. occasional cause of _____ and _____ 4. Antibiotic treatment can be ineffective T/F

Answer 33

1. HOSPITAL patients 2. opportunistic infections 3. septicemia meningitis 4. TRUE - because the organisms are frequently resistant to multiple antibiotics (resistance genes)

Question 34

What important SPECIES is part of the genus Serratia under Tribe V Klebsielleae? Habitat? How do Serratia appear on MacConkey?

Answer 34

S. Marcescens Widely distributed in the environment Appear RED - not because fermenting lactose but because the colonies are RED

Question 35

Name some clinical syndromes of Serratia.(5) What syndromes relate to IV drug addicts? (2 new ones)

Answer 35

1. Nosocomial infections 2. pneumoniae, 3. septicemia, 4. UTI 5. surgical wound and cutaneous infections. IV DRUG USERS: 1. Endocarditis 2. Osteomyelitis

Question 36

1. What are the species in TRIBE VI Proteae? (2) 2. a) What are the KEY ID FEATURES ? (TEST question) b) Lactose neg or pos? c) Urease neg or pos? 3. Habitat?

Answer 36

1. P. mirabilis P. Vulgaris 2. SWARMING observed on blood agar b) Lactose NEGATIVE c) Strongly UREASE POSITIVE 3. Soil, water and intestinal tract of humans and animals.

Question 37

What is the only organism that SWARMS and grows in spurts?

Answer 37

PROTEAE!!! (mirabilis & Vulgaris) | - indol test to separate the two

Question 38

Which of the Proteus species is described by the following: 1. most commonly recovered from infected sites in IC patients (immunocompromised) 2. is most frequently isolated species, cause of UTI and wound infections. - Strongly urease positive produces highly alkaline urea which can lead to renal CALCULI composed of struvite (magnesium ammonium phosphate) --test question

Answer 38

1. P. Vulgaris 2. P. Mirabilis (think of balls--> urease positive (a lot of ammonia and Co2) --> HIGH ALKALINE UREA --> renal calculi--> make struvite)

Question 39

Proteas Mirabilis causes ___ and has a ____ odor. Tx? What type of motility does it exhibit when plated? (only one that does this)

Answer 39

1. UTI 2. Fishy odor 3. SULFONAMIDES (also treat nocardia with sulfonamides) 4. SWARMING MOTILITY - because it is urease positive it produces a lot of ammonia and CO2 which leads to a very alkaline environment creating STRUVITE stone precipitates in the renal pelvis --> CALCULI form

Question 40

Yersinia Enterolitica: 1. Pinpoint colonies on MacConkey at ____ 2. Biochemical tests should be incubated at ___ Celcius 3. Usually transmitted from what 3 things. 4. Causes acute ___ or pseudo ____

Answer 40

1. 24 h 2. 25C 3. a) puppy feces (kids) b) contaminated milk c) pork 4. Acute diarrhea or Pseudoappendicitis (RLQ pain)

Question 41

Y. Enterolitica: 1. Most common spp in ______ 2. Widely distributed in _____ 3. Epizootic outbreaks of ___ (4) 4. Predominant subgroup?

Answer 41

1. clinical specimens 2. lakes and reservoirs 3. - diarrhea - lymph-adenopathy, - pneumonia, and - spontaneous abortions 4. O:3

Question 42

1. What is the major reservoir for infection of Y. Enterocolitica? 2. Associated with? 3. Portal of entry?

Answer 42

1. PIGS for infection in humans 2. Associated with household preparation of chitterlings 3. ORAL DIGESTIVE ROUTE

Question 43

Y. Enterocolitica: Organism adheres to and penetrates the ileum causing what (3) What does it mimic? Most common in ____.

Answer 43

1. terminal ileitis 2. lymphadenitis 3. and acute enterocolitis. 2. Mimics APPENDICITIS (also in first aid) 3. CHILDREN Enterocolitis accounts for 2/3 of infection. Diarrhea, fever, abdominal pain lasting as long a 1-2 weeks. - Chronic form can persist mos to > yr

Question 44

Y. Enterocolitica

Answer 44

1. Also associated w/transfusion related sepsis, arthritis, intraabdominal abscess, hepatitis, osteomyelitis 2. Blood contamination occurs due to asymptomatic Y. enterocolitica bacteremia at time of blood donation 3. Y. enterocolitica can proliferate in blood stored at 4o C after 2-3 weeks

Question 45

A 1-year-old African-American patient was brought into the emergency room of an intercity hospital suffering from diarrhea and subsequent dehydration. The family reports that the illness began a couple of days after Christmas. In questioning the parents about food-born source of the infection the parents reported serving chitterlings to the adults but not the children. A stool specimen sent to the laboratory grew a lactose-negative gram-negative bacillus that gave biochemical reactions typical of E. coli except that the organism was urease positive. What is the most likely identity of the bacterium? ``` E. coli 0157:H7 Salmonella serotype arizonae Yersinia enterocolitica Vibrio cholerae Edwardsiella tarda ```

Answer 45

Y. Enterocolitica