Bacteriology- Gram negative bacilli

Question 1

Enterobacteraceae classification

Answer 1

Lactose fermenter- E.coli, Klebsiella, Citrobacter, Enterobacter
Late lactose fermenter- Shigella sonnei
Non lactose fermenter- Shigella, Salmonella, Proteus, Yersinia

Question 2

Motility of enterobactericeae organisms

Answer 2

All except Shigella and Klebsiella are motile

Question 3

IMViC test results of enterobactericeae organisms

Answer 3

Shigella and Yersinia show only methyl red test +

E. coli and Klebsiella are opp- E.coli ++–, Klebiella –++

Salmonella is -+-+

Question 4

Urease test + is shown by

Answer 4

Klebsiella
Proteus

Question 5

Urease positive organisms

Answer 5

‘PUNCHKSS’
Proteus
Ureaplasma
Nocardia
Cryptococcus
Helicobacter
Klebsiella
Staph epidermidis
Staph saprophyticus

Question 6

If result is positive for IMV tests, the color is

Answer 6

Red

Question 7

If result is positive for citrate, the color is

Answer 7

Blue

Question 8

MacConkey agar is done for

Answer 8

Lactose fermentation
Pink color= lactose fermenter

Question 9

Constituents of MacConkey agar

Answer 9

‘PLANT’
Peptone
Lactose– differential media
Agar
Neutral red- indicator media
Taurocholate (bile salts)- selective media

Question 10

CLED medium
What is its indicator?

Answer 10

Cysteine Lactose Electrolyte Deficient
Indicator: Bromothymol blue
Allows growth of gram positive and negative organisms
To identify urinary pathogens

Question 11

EMB agar

Answer 11

Eosin Methylene Blue
Blue or black colonies with metallic sheen around it

Question 12

Media used to demostrate lactose fermentation

Answer 12

MacConkey agar
CLED (better)
EMB

Question 13

Enteropathogenic E.coli
1. Seen in?
2. characteristics?

Answer 13

Causes pediatric/ infantile diarrhoea
Forms bundle forming pili/ plasmid coded
shows attachment effacement lesions

Question 14

Enterotoxigenic E.coli

Answer 14

Caused traveller diarrhoea
Using colonization factor Ag

Question 15

Enteroinvasive E.coli

Answer 15

Dysentery (similar to Shigella)
Uses virulence factor Ag
Sereny test +

Question 16

Sereny test

Answer 16

mucopurulent keratoconjunctivitis on inoculation of bacteria into eye of guinea pig
Seen in EIEC, Shigella

Question 17

Anton test is seen in

Answer 17

Listeria
Similar to sereny test

Question 18

Kass criteria

Answer 18

> 10^5 CFU/ml is considered as UTI

Exceptions: ‘SPA’
Suprapubic aspiration
gram Positive organism +
Antibiotics/ diuretic intake

Question 19

EHEC

Answer 19

Causes HUS (0157:H7)
Sorbitol MacConkey Agar (SMAC) -ve

Question 20

Entero Aggregative E coli

Answer 20

Persistent diarrhoea
Stacked brick appearance

Question 21

Strains of E coli

Answer 21

EIEC
ETEC
EAEC
EHEC
EPEC
DAEC (Diffuse adherent E coli)

Question 22

K. pneumoniae

Answer 22

Lactose fermenter
Friedlander’s bacillus
Mucoid colony (bc capsulated)
String test positive

Question 23

K. ozeanea causes

Answer 23

atrophic rhinitis

Question 24

Mikulicz cells

Answer 24

Big foamy macrophages with pink bodies inside called Russell bodies

Question 25

Donovan bodies

Answer 25

K. granulomatis (that causes donovanosis)

Question 26

Which stains are used to do bipolar staining?

Answer 26

Wright Giemsa stain Wayson stain

Question 27

Donovan bodies show _____ appearance

Answer 27

Safety pin appearance

Question 28

Other organisms that show safety pin appearance

Answer 28

V. parahemolyticus Yersinia pestis K. granulomatis H. ducreyi Burkholderia

Question 29

Serratia can cause pseudohemoptysis d/t red pigment called

Answer 29

Prodigiosin

Question 30

Proteus shows ____ growth

Answer 30

Swarming growth

Question 31

Proteus

Answer 31

PPA (phenyl pyruvic acid test) positive fishy odor Diene's phenomenon (if same strain, will merge)

Question 32

Swarming growth is seen in

Answer 32

Proteus V. parahemolyticus, alginolyticus Serratia B. cereus C. tetani

Question 33

Diene's stain is used in

Answer 33

Mycoplasma

Question 34

What are the different species of Shigella?

Answer 34

S. dysenteriae (most severe, produces Shiga toxin) S. flexneri (common in India). S. boydii (less common). S. sonnei (mildest infection, MC in the world).

Question 35

Transport media for Shigella

Answer 35

Sach's Buffered glycerol saline

Question 36

Enrichment media for Shigella and Salmonella

Answer 36

Selenite F broth Tetrathionate broth

Question 37

Selective media for Shigella and Salmonella

Answer 37

XLD-Xylose Lysine Deoxycholate DCA- Deoxycholate agar HE- Hektoen enteric agar SS- Salmonella Shigella agar

Question 38

Treatment for Shigella and Salmonella

Answer 38

Ciprofloxacin

Question 39

Type of fever seen in Salmonella infection

Answer 39

Step ladder pattern fever

Question 40

Features of Enteric fever

Answer 40

Longitudinal ulcers Faget sign Rose spots (2nd to 3rd week, fades on pressure) Pea soup diarrhoea Soft palpable spleen, liver

Question 41

Faget's sign

Answer 41

relative bradycardia

Question 42

On Wilson Blair media, what is the appearance of colonies?

Answer 42

Jet black colonies

Question 43

Testing done in each week for typhoid fever

Answer 43

Week 1- blood culture week 2- Widal test, antibody test week 3- stool culture week 4- urine culture

Question 44

Typhoid O antigen is? Typhoid H antigen is?

Answer 44

Somatic Ag Flagella Ag

Question 45

Which antigen is different for all 3 typhoid species?

Answer 45

Flagella Ag

Question 46

___ antigen of typhoid appears first and disappears first.

Answer 46

O antigen

Question 47

New tests for Salmonella antigens

Answer 47

Typhidot Dot blot

Question 48

Best media for S. typhi

Answer 48

Wilson and Blair media

Question 49

Species of Yersinia

Answer 49

Y. pestis Y. enterocolitica Y. pseudotuberculosis

Question 50

Features of Y. enterocolitica and Y. pseudotuberculosis

Answer 50

They cause gastroenteritis They have differential motility They are urease positive

Question 51

Optimum temperature for growth of Yersinia

Answer 51

-25 C Incubate for 4 C for 1 week

Question 52

Characteristic appearance of Yersinia colonies

Answer 52

Bull's eye appearance on CIN agar

Question 53

Types of Plague

Answer 53

Bubonic (2-7 days IP) LN enlarged, painful; fever Pneumonic (1-3 days IP) Resp +, bioterrorism Septicemic (2-7 days IP)

Question 54

How is plague diagnosed?

Answer 54

Wayson stain/ Wright stain/ Giemsa stain: Bipolar staining (safety-pin appearance). Culture: Blood, sputum, bubo aspirate on MacConkey or blood agar. Serology & PCR for confirmation. Ghee broth: Stalactile growth

Question 55

What is the treatment for plague?

Answer 55

Streptomycin (first-line), Gentamicin, Doxycycline.

Question 56

How is bubonic plague transmitted

Answer 56

Transmission: Flea bite (Xenopsylla cheopis).