Micro 107 Unit 6

Question 1

Which is the only Enteric bacteria whcih is oxidase positive?

Answer 1

Plesiomonas spp.

Question 2

What are the selective and differential media for Enterobacteriacae(Enterics)?

Answer 2

MAC, EMB, HE(K), XLD.

Question 3

What is MAC differential for?

Answer 3

Lactose fermentation

Question 4

What is EMB differential for?

Answer 4

Lactose and Sucrose fermentation

Question 5

What is HE(K) differential for?

Answer 5

Lactose and Sucrose fermentation. Bile salts inhibit gram-positive and some gram-negative

Question 6

What color do Shigella colonies apear as on AXD agar?

Answer 6

Colorless or red

Question 7

What are the two major types of pathogens?

Answer 7

Opportunistic: Normal Flora
Primary: Ingesting contaminated food or water

Question 8

What are the key 3 primary Enteric pathogens?

Answer 8

Salmonella, Shigella, and Yersinia

Question 9

What are the general characteristics of Escherichia coli (E. coli)

Answer 9

Dry pink colony with a halo on MAC
Green metallic sheen on EMB

Question 10

What are the key tests described in the IMViC accryonym

Answer 10

Indole
Methyl red
Voges-Proskauer
Citrate

Question 11

What is the IMViC for E. coli

Answer 11

++–

Question 12

What carbs does E. coli ferment

Answer 12

Glucose, Lactose, Trehalose, and Xylose
GTXL

Question 13

Why is Uropathogenic E. coli clinically significant

Answer 13

Most common cause of UTI’s in humans

Question 14

What are the 5 major categories of E. coli

Answer 14

ETEC
EPEC
EIEC
EHEC
Enteroadherent
- DAEC
- EAEC

Question 15

What climate is ETEC generally acquired in giving it the name “travelers diarrhea”

Answer 15

tropical and subtropical climates

Question 16

Where do EPEC outbreaks occur

Answer 16

Nurseries and daycares

Question 17

What conditions can EHEC O157:H7 lead to

Answer 17

Hemorrhagic diarrhea
Colitis
Watery diarrhea progressing to bloody diarrhea in young children and elderly
HUS

Question 18

What are the diagnostic tests for E. coli O157:H7

Answer 18

Primary screening on a stool culture
MAC agar with sorbitol (SMAC)

Question 19

What seperates E. coli 157:H7 from most other E. coli

Answer 19

Does not ferment sorbitol in 48 hours

Question 20

Klebsiella, Enterobacter, Serratia, Pantonea, Cronobacter, and Hafnia are associated with what kind of infections

Answer 20

opporunistic and nosocomial

Question 21

Klebsiella pnumoniae is the most common isolate of the Klebsiella family and appears ______ on a BAP

Answer 21

moist, gray, mucoid colonies

Question 22

What are the 4 clinically significant species of Enterobacter

Answer 22

E. cloacae
E. aerogenes
E. geroviae
E. hormaechei

Question 23

Which 2 Enterobacter species are the most commonly isolated

Answer 23

E. CLoacae
E. aerogenes

Question 24

Proteus Species are what kind of bacteria

Answer 24

normal intestinal microbiota (Normal Flora)

Question 25

What is the colony morphology of Proteus spp.

Answer 25

Swarming colonies and a distinct "burnt chocolate" smell

Question 26

The Morganella spp.'s only species, M. morganii is isolated in ___ infections and is a cause of ___

Answer 26

UTI Neonatal Sepsis

Question 27

P. stuartii is implicated in nosoomial outbreaks in what unit of the hospital

Answer 27

Burn unit

Question 28

P. stuartii is isolated in ___ cultres

Answer 28

Urine

Question 29

What makes Providencia spp. difficult to treat

Answer 29

High resistance to antimicrobials

Question 30

Edwardsiella does not grow on what medium

Answer 30

Simmon's citrate

Question 31

Of the 11 Citrobacter spp. what are the 3 most common isolated

Answer 31

C. freundii C. koseri C. braakii

Question 32

What infection is C. freundii associated with

Answer 32

UTI

Question 33

What infection is C. koseri associated with

Answer 33

Neonatal Meningitis

Question 34

What is the colony morphology of Salmonella spp.

Answer 34

Clear, colorless, non-lactose fermenting colonies with black centers on MAC agar

Question 35

What tests do we run to dfferentiate Salmonella subgroups

Answer 35

Lysine decarboxylase rules out S. paratyphi Ornithone decarboxylase rules out S. typhi Trehalose fermentation rules out S. cholaraesuis

Question 36

What is the primary virulence factor of S. enterica

Answer 36

Enterotoxin: involved in gastroenteritis

Question 37

Clinical infections of S. enterica present as ____ and are caused by ___

Answer 37

Food poisoning with vomiting and diarrhea Ingestion of organism in contaminated food

Question 38

When do symptoms of S. enterica appear

Answer 38

8-36 hours after ingestion of contaminated food

Question 39

Most cases of Salmonella gastroenteritis (Salmonellosis) are ____

Answer 39

Self Limiting

Question 40

Development of Typhoid fever, caused by S. typhi can lead to

Answer 40

Fever, malaise, anorexia, lethargy, myalgia, and a dull headache

Question 41

Define Carrier State

Answer 41

Individuals who recover from infection but harbor the organisms in the gallbladder

Question 42

All Shigella spp. can cause ___

Answer 42

Dysentery

Question 43

The only resivoir of Shigella spp. is ___

Answer 43

Humans

Question 44

Local inflammation and shedding of intestinal lining containing mucus, blood, ulcer formation, and tenesmes (rectal prolapse)

Answer 44

Dysentery

Question 45

Biochemical identificaton of SHigella spp.

Answer 45

No urease production No H2S in TSI Nonmotile

Question 46

Which Yersinia spp. is considered a class A bioterrorism agent

Answer 46

Y. pestis

Question 47

Y. pestis causes _____

Answer 47

Plague in the Bubonic, Septicemic, and Pneumonic forms

Question 48

When does the septicemic form of the plague occur

Answer 48

when the bacteria migrate to the bloodstream

Question 49

What specialized agar is used for the identification of Y. enterocolitica

Answer 49

CIN agar

Question 50

What cultures is Kluyvera isolated from

Answer 50

Respiratory, Urine, and Blood

Question 51

What transport media must labs provide for Enterobacteriaceae

Answer 51

Cairy-blair Amies Stuart

Question 52

What should all fecal specimens be screened for

Answer 52

Salmonella Shigella Campylobacter

Question 53

What selective media should be used for stool specimens

Answer 53

HE(K) XLD EMB

Question 54

What environment is Vibrio commonly found in

Answer 54

Aquatic environments including fresh and salt water

Question 55

An increase in the isolation of Vibrio can be linked to

Answer 55

Increased consumption of seafood Undercooked or raw seafood

Question 56

V. cholera is the causative agent of ____

Answer 56

cholera

Question 57

Where does V. cholera originate

Answer 57

The Bengal region of India and Bangledesh

Question 58

What are the clinical manifestations of cholera

Answer 58

Severe acute gastroenteritis Rice-water stool ( stool with fleks of mucus)

Question 59

What is the recomended treatment of cholera

Answer 59

IV and oral fluids containing electrolytes

Question 60

What is the second most common Vibrio spp.

Answer 60

Vibrio parahaemolyticus

Question 61

V. parahaemolyticus was discovered in ___

Answer 61

Japan in 1950 Known as summer diarrhea

Question 62

As of 2007 the CDC requires that cases of _____ be reported to local and state public health agencies

Answer 62

V. vulnificus

Question 63

If clinical history indicates Vibrios use

Answer 63

thiosulfate, citrate, bile salts, sucrose (TCBS agar)

Question 64

Biochemical identification of Vibrios spp.

Answer 64

Catalase positive Oxidase positive Ferments glucose Reduces nitrate to nitrite Susceptible to Vibriostat disc

Question 65

Biochemical identification of Aeromonas

Answer 65

Oxidase positibe Indole positive

Question 66

Where is Plesimonas found

Answer 66

Soil and aquatic environments

Question 67

What are the 3 major clinical types of gastroenteritis

Answer 67

Watery diarrhea Subacute or chronic disease( 2 weeks to 3 months) Dysenenteric form resemblig cholitis

Question 68

Who is most at risk of Plesimonas

Answer 68

Vets and zookeepers

Question 69

What agar can be used to enhance the isolation of Plesimonads

Answer 69

IBB

Question 70

Biochemical Identification of Plesimonas

Answer 70

Oxidase Positive

Question 71

What is unique to Campylobacter spp.

Answer 71

They are Microaerophillic organisms - They require oxygen but at a concentration of only 5%

Question 72

The transmisson of Campylobacterioses has ben attributed to

Answer 72

Infected pets such as dogs cats and birds

Question 73

What is the most common cause of bacterial gastroenteritis

Answer 73

Campylobacter jejuni

Question 74

What symptoms follow infection of Campylobacer jejuni

Answer 74

Cramps, bloody diarrhea, fever, chills, and rarely nausea and vomiting

Question 75

Helicobacter pylori is repsonsible for

Answer 75

Damaging tissue, resulting in gastric, peptic, and duodenal ulcers

Question 76

What transport medium must be used for Campylobacter

Answer 76

Cary-Blair for stool samples

Question 77

What environment must Campylobacter plates be incubated in

Answer 77

Microaerophillic, and Capnophilic 5%-10% oxygen and 10% CO2 at 42*C

Question 78

What is the microscopic morphology of Campylobacter

Answer 78

Non-spore forming gram negative rods S or segull-wing shape

Question 79

biochemical identification of Campylobacter

Answer 79

Oxidase positive Exhibits a "darting" motility on hanging drop preperations

Question 80

For the laboratory identification of Helicobacter, gastric biopsy can be tested for the presens of a ___

Answer 80

Rapid Urease reaction

Question 81

Rapid Urease reaction test

Answer 81

Requires christensen's urea Rapid color change in 2 hours

Question 82

Another commercial rapid test for Helicobacter

Answer 82

Urea breath test

Question 83

Miscellaneous Gram negative bacilli

Answer 83

Do not ferment carbohydrates grow only in aerobic environments prefer moist environments

Question 84

Clinical infections of non-fermenters

Answer 84

Account for 15% of all gram-negative bacilli isolated in clinial infections (Pseudomonas aeruginosa 5-15%)

Question 85

Pseudomonas aeruginosa accounts for ____ of all nosocomial infections, especially pneumonia and bacteremia

Answer 85

5-15%

Question 86

Pseudomonas aeruginosa can cause

Answer 86

pulmonary disease, especially among individuals with cystic fibrosis

Question 87

What is the primary virulence factor of Pseudomonas aeruginosa

Answer 87

Alginate -A polysaccharide polymer

Question 88

Overproduction of the Alginate factor in Pseudomonas aeruginosa produces

Answer 88

Mucoid colonies. Seen primarily in cystic fibrosis patients

Question 89

Laboratory identification of Pseudomonas aeruginosa

Answer 89

Many strains produce a fruity grape like odor caused by the presence of 2-aminoacetophenone

Question 90

Biochemical identification of Pseudomonas aeruginosa

Answer 90

Motile Indole negative ADH positive Growth at 42*C

Question 91

Antimicrobial susceptibility for Pseudomonas aeruginosa

Answer 91

Carbapenems Flouroquinolones

Question 92

Clinical infections for P. stutzeri

Answer 92

Endocarditis Septic arthritis Conjunctivitis

Question 93

Culture and colony morphology for P, stutzeri

Answer 93

Wrinkled, leathery, adherent colonies that may produce a light yellow or brown pigment

Question 94

P. mendocina is considered

Answer 94

A contaminant

Question 95

Acinetobacter spp. appears as

Answer 95

gram negative coccobacilli