Enterobacteriales Flashcards

1
Q

Enterobacteriales

Gram (positive or negative?) _____

Motile by ___________; some are non motile

A

Negative rods

peritrichous flagella

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2
Q

Enterobacteriales

Form endospores or microcysts

T/F

A

F

Do not form endospores or microcysts

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3
Q

Enterobacteriales

Are not acid-fast.

T/F

A

T

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4
Q

Enterobacteriales

In terms of oxygen, are either ______ or _______

A

aerobes/facultative anaerobes

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5
Q

Enterobacteriales

grow well on standard lab media at 19-22
None grow on D glucose as the sole source of carbon
some require vitamins and/ or amino acids.
Have both oxidative and fermentative metabolism

T/F

A

F. 22–35
F. Some do
T
T

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6
Q

An endospore is a _____,______, and _________ structure produced by certain bacteria

A

dormant, tough, and non-reproductive

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7
Q

Enterobacteriales

produce _____ and ______ during fermentation of d-glucose, other carbohydrates and polyhydroxyl alcohols.

A

acid and visible gas bby

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8
Q

Enterobacteriales

Flourishes in a salty environment

T/F

A

F

Not halophilic

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9
Q

Enterobacteriales

Most are catalase-(positive or negative?) , except for __________ O group 1 and _______.

Most are oxidase (positive or negative?) , except for ________.

Most reduce _____ to _____, except _________

A

positive

Shigella dysenteriae; Xenorhabdus

Negative; Plesiomonas

nitrate to nitrite; Saccharobacter fermentatus

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10
Q

Enterobacteriaceae- family

Small or Large ?
(Homo or Hetero?) geneous group
Habitat:_______

The family includes the following genius:( ___,____,____,____,_____,____,______and others

A

Large
Hetero

gut of man and animals

Escherichia, Shigella, Salmonella, Enterobacter, Klebsiella, Serratia, Proteus,

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11
Q

Enterobacteriaceae- family

Some such as _________, are part of the normal microbiota and incidentally cause disease

others e.g. the ___ and ______ , are regularly pathogenic for humans.

A

Escherichia coli

salmonellae and shigellae

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12
Q

Enterobacteriaceae- family

possess a (simple or complex?) antigenic structure
produce a variety of toxins and other virulence factors

A

Complex

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13
Q

E.coli

In terms of oxygen is __________.

A

Aerobic and facultatively anaerobic

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14
Q

E. coli

Motile or non motile?

A

Motile by peritrichous flagella

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15
Q

Ecoli is motile by ______ flagella

A

Motile by peritrichous flagella

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16
Q

E.coli

Catalase _______
Oxidase _______.

A

Positive

negative

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17
Q

Ecoli
______________ are formed from most fermentable carbohydrates

When Lactose is fermented, it Usually (do or do not ?) produce H2S.

Occur naturally in the (upper or lower?) part of the ______ of warm-blooded animals

A

Both acid and gas

Do not

Lower; intestine

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18
Q

E.coli can ferment glucose
E.coli can ferment lactose

T/F

A

T
T

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19
Q

Diseases caused by E. coli

Diarrhoea

• ___________
•__________

•______________
•____________
•________
•____________

A

shiga toxin-producing E. coli (STEC)

Enterotoxigenic E. coli (ETEC)

Enteroaggregative E. coli (EAEC)

Enteroinvasive E. coli (EIEC).

Enteropathogenic E. coli (EPEC)

Diffusely adherent E. coli (DAEC).

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20
Q

Diseases caused by E. coli
Diarrhoea
• Shiga toxin-producing E. coli (STEC): This is the bacteria most commonly known for E. coli _______________

E.g E. coli _______

A

food contamination.

O157:H7

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21
Q

shiga toxin-producing E. coli (STEC): AKA ______________ and _________

A

enterohemorrhagic E. coli (EHEC) and verocytotoxin-producing E. coli (VTEC).

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22
Q

Shiga-like toxin (STEC ) has been associated with __________, a severe form of diarrhea, and with ___________

A

hemorrhagic colitis

hemolytic uremic syndrome

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23
Q

Enterotoxigenic E. coli (ETEC): This strain is commonly known as a cause of ____________

Enteroaggregative E. coli (EAEC) causes __________ diarrhea.

A

travelers’ diarrhea.

acute and chronic

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24
Q

Entero_______ E. coli is an important cause of diarrhea in infants.

A

pathogenic

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25
Q

Commonest cause of UTI is???

A

E.coli infection

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26
Q

Ecoli causes sepsis

T/F

A

T

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27
Q

E. coli is one of the leading causes of meningitis

T/F

A

T

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28
Q

Diagnosis of E.coli

Media: grows well on standard laboratory medium but _____ agar or ____ is usually used to demonstrate lactose fermentation

________ may be used for identification and resistance testing

A

MacConkey; EMB

Chromagar

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29
Q

Klebsiella

(Motile or nonmotile?)

Gram-(positive or negative?)

oxidase-(positive or negative?)

____-shaped bacteria with a prominent ___________

A

Non motile; negative; negative

rod; polysaccharide capsule

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30
Q

Named after German-Swiss microbiologist _____— (1834–1913).

___________ described Klebsiella bacillus which is why it was termed __________ for many years

A

Edwin Klebs

Carl Friedlander

Friedlander bacillus

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31
Q

Klebsiella spp. are ubiquitous in nature

T/F

A

T

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32
Q

Klebsiella spp.

are a part of the human and animal’s normal flora in the _____,_____, and _____

A

nose, mouth and intestine

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33
Q

K pneumoniae is present in the _____ and _____ of about ___% of normal individuals

A

respiratory tract and feces

5

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34
Q

Klebsiella pneumoniae subspecies _______ has been isolated from the nasal mucosa in ozena
K pneumoniae subspecies _________ form rhinoscleroma

A

ozaenae

rhinoscleromatis

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35
Q

Klebsiella _____ can cause a variety of nosocomial infections.

A

oxytoca

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36
Q

Klebsiella oxytoca may be resistant to multiple antibiotics.

T/F

A

T

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37
Q

There is evidence that K. oxytoca can cause ________ associated with antibiotic use

A

hemorrhagic colitis

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38
Q

Difference between K.oxytoca and K.pneumoniae

A

K.oxytoca is distinguished from K. pneumoniae based on its ability to produce indole from tryptophan

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39
Q

Klebsiella _________ (formerly ________________) causes a chronic genital ulcerative disease, granuloma _____,

A

granulomatis

Calymmatobacterium granulomatis

inguinale

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40
Q

Characteristics of klebsiella

Oxygen= _______

Grow well on ______ media

grow best between ____ and ___°C and at pH ____

A

Facultative anaerobes

Standard

35 and 37

7.2

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41
Q

Characteristics of Klebsiella

most produce _______ colonies on plates because of the production of a luxuriant __________ or ________ , which can be used for serologic identification

A

highly mucoid

polysaccharide capsule or slime layer

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42
Q

Some klebsiella are motile , some are non-motile

T/F

A

F

all are nonmotile

43
Q

Biochemical characteristics of klebsiella

ferment lactose (positive or negative?)

Indole (positive or negative?) except for K.______ and K.________

A

Positive

Negative ; oxytoca; ornitholytica

44
Q

Virulence factors of klebsiella

Polysaccharide capsule:
The principal virulence factor that has been described for K. pneumoniae is its polysaccharide capsule, which consisits of repeating subunits of ____________ and, very often, _________ (as negatively charged components)

more than _____ antigenic varieties and is responsible for its mucoid colony phenotype.

Some capsule types, such as ____ and ____, may be more important than others.

The mechanism by which capsule promotes virulence is believed to be due to ____________
Animal models have revealed a role for the capsule in infection of the ______ and ______

A

four to six sugars

uronic acids

70

K1 and K2

inhibition of phagocytosis

urinary tract and pneumonia.

45
Q

Virulence factors of klebsiella

•Adhesins
-K. pneumoniae can produce a variety of ______ types, including ______ that are involved in adherence to host cells.

•______ resistance
Pathogenic strains are able to resist ______

•LPS
-an endotoxin
-important in the pathology of _______

A

fimbrial; type 1 pili

Serum ; complement proteins

septicemia

46
Q

Virulence factors of klebsiella

Siderophores

•are (low or high?) -molecular-weight ________ that are capable of ___________________

A

Low; iron chelators

competitively taking up iron bound to host proteins

47
Q

Iron is an essential factor in bacterial growth

T/F

A

T

functioning mainly as a redox catalyst in proteins participating in oxygen and electron transport processes.

48
Q

enterobacteria synthesize a variety of siderophores, which belong to two different chemical groups, one consisting of the ______-type siderophores and one consisting of the ____-type siderophores.

A

phenolate

hydroxamate

49
Q

All strains of K. pneumoniae are resistant to ______ as a result of the presence of a chromosomal gene encoding a ______________

A

ampicillin

penicillin-specific β- lactamase.

50
Q

In addition, nosocomial( hospital acquired infection) isolates are frequently resistant to numerous other antibiotics as a result of the acquisition of _______________

A

multidrug resistant plasmids.

51
Q

Klebsiella is the ___ most common cause of UTIs

A

3rd

52
Q

Klebsiella pneumoniae is a primary pathogen capable of causing ______,____,______ in otherwise healthy people.

Causes ______________ and occurs in those who are debilitated by various underlying conditions.

A

UTIs, liver abscess, and pneumonia

healthcare associated infections(HCAIs)

53
Q

HCAIs caused by K. pneumoniae include ___ infections, ______ infections and other invasive devices, _____ infections, peritonitis, and _____; in addition to UTIs, liver abscess, and pneumonia

A

wound

blood stream

biliary tract

meningitis

54
Q

Salmonella species

Gram-(positive or negative?)

flagellated or non-flagellated

Oxygen =—————- bacilli

A

Negative

Flagellated

facultatively anaerobic

55
Q

The taxonomic classification of the genus Salmonella is complex and problematic.
2 species: Salmonella _____ and Salmonella _______ with many subspecies.

A

bongori

enterica

56
Q

Characteristics of salmonella

Spore or Non spore-forming

_________ flagella

They are ____trophs

A

Non-spore forming

peritrichous

chemo

57
Q

S. enterica subspecies are found worldwide in ______-blooded animals and in __________
S. bongori is restricted to ___-blooded animals, particularly ______

A

warm; the environment.

cold

reptiles

58
Q

Biology, Virulence, and Disease of salmonella

Is a fermenter?

oxidase (positive or negative?)

Lipopolysaccharide consists of __________, core _____ (______), and ____(_____)

A

Yes

Negative

outer somatic O polysaccharide

polysaccharide; common antigen

lipid A (endotoxin)

59
Q

Biochemical of salmonella

Indole( positive or negative?)

Methyl red (positive or negative?)

VP (positive or negative?)
Citrate (positive or negative?)

S typhi (positive or negative?)

Hydrogen sulphide usually(positive or negative?)

A

Negative

Positive

Negative ; negative
Positive

positive

60
Q

Salmonella

Ferments _____ and ______ but not _____ and ____

A

glucose and mannitol

lactose and sucrose

61
Q

Salmonella

does not produce gas

T/F

A

F

62
Q

Subspecies of salmonella

Salmonella enterica serova ___

Salmonella serova _______

Salmonella enterica serova _____ in humans

Salmonella enterica serova choleraesuis in ____

Salmonella enterica serova ______ in humans

A

typhi

paratyphi

typhimurium

pigs

enteritidis

63
Q

Salmonella is intolerant of acids in phagocytic vesicles

T/F

A

F

Tolerant

64
Q

Salmonella Can survive in macrophages and spread from the intestine to other body sites

T/F

A

T

65
Q

Salmonella species are _____cellular pathogens

A

intra

66
Q

Non typhoidal salmonella serotypes

-can be transferred from _________ and from _________

  • they usually invade only the ______ and cause ________
A

animal-to-human

human-to-human

gastrointestinal tract; salmonellosis

67
Q

non typhoidal Salmonella can be invasive

T/F

A

T

68
Q

Non typhhoidal salmonella serotype can cause paratyphoid fever

T/F

A

T

By being invasive

69
Q

Typhoidal salmonella serotypes can only be transferred from ___________ , cause ______ infection, ______ and ______

A

human-to-human

food-borne

typhoid fever, and paratyphoid fever.

70
Q

Typhoid fever is caused by _________________- (the typhoidal form), or in addition spreads throughout the body, invades organs, and secretes ______ (the ____ form).
can lead to life-threatening ______ shock and ____ shock

A

Salmonella invading the bloodstream

endotoxins; septic

hypovolemic; septic

71
Q

Mechanism of infection of salmonella

Non typhoidal serotypes preferentially enter _____ on the intestinal wall by _______________, a process associated with intestinal ________ and ______.

They disrupt _____between the cells of the intestinal wall, impairing the cells’ ability to _________________________ into and out of the intestine

A

M cells

bacterial-mediated endocytosis

inflammation and diarrhoea.

tight junctions ; stop the flow of ions, water, and immune cells

72
Q

In non typhoidal salmonella serotypes, The combination of the inflammation caused by bacterial-mediated endocytosis and the disruption of tight junctions is thought to contribute significantly to the induction of ________.

A

diarrhoea

73
Q

Mechanism of infection of salmonella

Pathogenic salmonellae ingested in food survive passage through the _____ barrier

invade the mucosa of the small and large intestine and ________.

Invasion of epithelial cells stimulates the release of _______ which induce an ______.

The acute inflammatory response causes _____ and may lead to _____ and destruction of the mucosa.
The bacteria can disseminate from the intestines to cause _________

A

gastric acid

produce toxins

proinflammatory cytokines ; inflammatory reaction

diarrhea; ulceration; systemic disease.

74
Q

Epidemiology of salmonella

Most infections are acquired by ___________________________ are the
most common sources of infection)

________________ spread in children

A

eating contaminated food products (poultry, eggs, and dairy products

Direct fecal-oral

75
Q

Salmonella ____ and Salmonella ______ are strict human pathogens (no other reservoirs);

these infections are passed person to person

(Symptomatic or Asymptomatic?) (short or long?) -term colonization occurs commonly

A

Typhi; Paratyphi

asymptomatic; long

76
Q

Individuals at risk for infection of salmonella include those who eat _____________ poultry or eggs
patients with ___________ levels, and immunocompromised patients

Infections occur worldwide, particularly in the ____ months of the year

A

improperly cooked

reduced gastric acid

warm

77
Q

Treatment, Prevention, and Control of salmonella

Antibiotic treatment not recommended for _______

T/F

With reason

A

enteritis

T

because this may prolong the duration of disease

78
Q

There are vaccines against salmonella Typhi

T/F

A

T

79
Q

Shigella app

Named after ______, who first discovered it in 1897
______pathogenic microorganism
The causative agent of _____
causes disease in _____, but not in other mammals.
only naturally found in _____ and _____

A

Kiyoshi Shiga

food borne

shigellosis

primates

humans and gorillas

80
Q

Shigella is one of the leading bacterial causes of diarrhea (typically dysentery) worldwide

T/F

A

T

81
Q

Shigella species are classified into 4 serogroups

Serogroup A: S.______ (15 serotypes)
Serogroup B: S. _____ (six serotypes) Serogroup C: S._______ (19 serotypes) Serogroup D: S.______ (one serotype)

A

dysenteriae

flexneri

boydii

sonnei

82
Q

MORPHOLOGY AND CHARACTERISTICS of shigella

_______ forms occur in young cultures

(Motile or non-motile ?)

Encapsulated or Non-Encapsulated

Spore forming or Non spore-forming

A

Coccobacillary
Non-motile
Non-encapsulated
Non-spore forming

83
Q

Characteristics of shigella

Does or does not ferment lactose?

form acid or does not form acid from carbohydrates

A

do not ferment lactose, or do so slowly.

form acid from carbohydrates but rarely produce gas.

84
Q

SHigella ________ is considered the most virulent, and can produce a potent cytotoxin known as _____ toxin.

A

dysenteriae

Shiga

85
Q

Shigella _______ can produce shiga toxin

A

Dysenteriae

86
Q

MODE OF TRANSMISSION of shigella spl

_______ route

transmission is typically through one of three mechanisms:

1)_____ of ______

2)_______ of _____

3)by ________ by ______

Spread of infection linked to ___ has also been recorded.

A

Fecal-oral

ingestion of contaminated foods

drinking of contaminated water

person-to-person contact by anal sexual contact.

flies

87
Q

Shigella infections are almost always limited to the ________

A

gastrointestinal tract

88
Q

bloodstream invasion by shigella is (rare or common?)

A

quite rare.

89
Q

Shigella

is highly communicable

the infective dose is on the order of 10^2 organisms

T/F

A

T

F(10^3)

90
Q

Pathogenesis of shigella

Invasion of _______ cells (eg, M cells) by induced ______, then ____ from the _____, multiplication and spread within the _________, and ________

A

mucosal epithelial

phagocytosis

escape; phagocytic vacuole; epithelial cell cytoplasm; passage to adjacent cells.

91
Q

Pathogenesis of shigella

______ in the wall of the large intestine and terminal ileum lead to ______ of the mucous membrane, superficial ______, bleeding, and formation of a“ _______ ” on the ulcerated area , which consists of fibrin, leukocytes, cell debris, a necrotic mucous membrane, and bacteria.
As the process subsides, _______ fills the ulcers, and _______ forms

A

Microabscesses; necrosis

ulceration; pseudomembrane

granulation tissue

scar tissue

92
Q

Virulence in Shigella species involves only plasmid-coded genes

A

F

Virulence in Shigella species involves both chromosomal-coded and plasmid-coded genes

93
Q

VIRULENCE FACTORS of shigella

Endotoxin

Upon _____, all shigellae release their toxic _______. This endotoxin probably contributes to the __________

A

autolysis

lipopolysaccharide

irritation of the bowel wall

94
Q

VIRULENCE FACTORS of shigella

•Shigella Dysenteriae Exotoxin
S dysenteriae type __ (Shiga bacillus) produces a heat- _____ exotoxin that affects both the ______ and ______

A

1; labile

gut and the central nervous system.

95
Q

Shigella Dysenteriae Exotoxin

The exotoxin is a protein that is antigenic
as an enterotoxin, it produces _____, inhibits ______ and ——— absorption in the small intestine.

as a “neurotoxin,” may contribute to the ______ and _______ of S dysenteriae infections and to the central nervous system reactions observed in them ( ______,______ ).

A

diarrhea; sugar and amino acid

extreme severity and fatal nature

meningismus, coma

96
Q

VIRULENCE FACTORS of shigella

Plasmids: Gene for synthesis of polypeptides that cause _____ is encoded on a large (220kb) plasmid.

Siderophores, a group of ____-coded genes, control the _________________________.

Enterotoxin : _______ (___)

A

cytotoxicity

plasmid

acquisition of iron from host cells from its protein-bound state

Shigatoxin; Stx

97
Q

Shigella

In the extra intestinal phase of infection by Gram-negative bacteria, _____ becomes one of the major factors that limit further growth.

A

iron

98
Q

LABORATORY IDENTIFICATION of shigella

Specimens Faeces/rectal swab
•Faeces should be collected in an appropriate sterile container, transported to the laboratory as soon as possible (if longer than __h keep at __oC), may be stored at __oC for 24 hours before culture.

•Rectal swabs put into a ___ transport medium containing modified ____ medium, transported to the laboratory as soon as possible. May be stored at ____ temperature for 24 hours before culture.

A

2; 4

4

tube; Stuart’s

room

99
Q

Culture for Shigella species

Shigella is a (fastidious or non-fastidious?) organism

Because of the nature of the specimens for culture, Shigella detection is still highly dependent on employing appropriate _______

A

non-fastidious

culture media.

100
Q

For optimal isolation of Shigella, two different selective media should be used.

A ____ – purpose plating medium of (low or high?) selectivity (e.g., __________ ) and A more selective agar medium (e.g. ____________).

A

general

Low

MacConkey-MAC

xylose lysine desoxycholate agar-XLD

101
Q

____________ agar (SS) should be used with caution because it inhibits some strains of Shigella dysenteriae.

A

Salmonella – Shigella

102
Q

There is a reliable effective enrichment medium for all types of Shigella

T/F
If T, mention it
If F, what is now used

A

F

There is no reliable effective enrichment medium for all types of Shigella, but Gram-negative (GN) broth and Selenite broth are frequently used.

103
Q

identification of individual Shigella species is often accomplished through slide ________ using absorbed _______

A

agglutination; rabbit antisera.

104
Q

_____ and _____ testing are used to differentiate Shigella from E. coli species

A

PCR and ELISA