Micro Practical

Front 1

how is gram stain performed

Back 1

1) apply crystal violet to smear, wash (G-,+)

2) apply Gram's iodine
3) add ethyl alochol 95%, wash (G-)
4) counterstain with safranin, wash (G-)
examine by oil immersion

Front 2

why do you we add 95% ethyl acohol

Back 2

for decolorization of gram negative

Front 3

mechanism of gram stain

Back 3

G+ve bact appear violet as
CW + CV + iodine --> insoluble complex in EA
G-ve appear red as this complex is soluble

Front 4

negative staining?

Back 4

india ink (cap) and negrosin

Front 5

STAPHYLOCOCCUS
classify?

Back 5

coagulase +ve: st. aureus

coagulase -ve: St.E and St.S

Front 6

STAPHYLOCOCCUS
classify according to endopigments

Back 6

st. Aureus: golden yellow
St. E : white
St. S: lemon yellow

Front 7

STAPHYLOCOCCUS
diseases?

Back 7

1: PYOGENIC infections
(focal as breast abscess, disseminated as osteomyelitis and meningitis)

2. TOXIN MEDIATED
Food poisoning, toxic shock and scalded

Front 8

STAPHYLOCOCCUS
3 toxins?

Back 8

heamolysin
leucocidins
enterotoxin

Front 9

STAPHYLOCOCCUS
3 enzymes?

Back 9

coagulase
staphylokinase
penicillinase

Front 10

STAPHYLOCOCCUS
selective media?

Back 10

mannitol salt agar (NaCl 10-15%)

Front 11

STAPHYLOCOCCUS
what is MRSA

Back 11

St.A resistant to B lactams, aminoglycosides and sensitive to vancomycin

Front 12

STAPHYLOCOCCUS
How to trace the source of infection/typing method?

Back 12

1- phage typing
2- antibiotic sensitivity

Front 13

STAPHYLOCOCCUS
normal carriage site of this organism?

Back 13

nose and skin

Front 14

STAPHYLOCOCCUS
mention 2 non pathogenic strains and how do u differentiate between it and the pathogenic strain?

Back 14

1- St.E: (peritonitis, septicemia and neonatal meningitis)
2- St.S (UTI in women)
Novobiocin: St.E sensitive

DD: path c+ve, MF, LG and BH

Front 15

STAPHYLOCOCCUS
antigenic structures?

Back 15

TA, protein A, coagulase, +-capsule

Front 16

STAPHYLOCOCCUS
specimen in TSS

Back 16

wound swab but not blood

(blood +ve in strept)

Front 17

STAPHYLOCOCCUS
mention 3 antibiotics NOT used in treatment

Back 17

penicillin
ampicillin
cephalosporins

Front 18

STAPHYLOCOCCUS
virulence factors

Back 18

structural: peptidoglycan layer, protein a, +- capsule)
products (toxins and enzymes)

Front 19

STAPHYLOCOCCUS
coagulase test ?

Back 19

st. a produces coagulase which binds to prothrombin forming a complex that initiates polymerization of fibrin

Front 20

STAPHYLOCOCCUS
types of coagulase tests

Back 20

1. slide (clumping test)
2. tube (standard coagulase test)

Front 21

STAPHYLOCOCCUS
how is the slide/clumping test performed?

Back 21

place two loopfuls of saline on a slide
emulsify part of a colony in each
add a loopful of plasma to ONE (other=control)

--> clumping (after shaking for one min)
5% false

Front 22

STAPHYLOCOCCUS
how is the standards coagulase test performed?

Back 22

- place half mil of dil. oxalated plasma in two tubes.
- add 5 drops of overnight broth culture of the strain in ONE tube
- incubate at 37* and read hourly up to six hours.
(if no clot, leave at rm temp overnight)

clot appears = positive

(positive, neg strain, dil plasma must be included as controls)

Front 23

STREPTOCOCCI
base of lancefield classification

Back 23

C antigen (by latex agglutination or ELISA)

Front 24

STREPTOCOCCI
classification according to hemolytic properties on blood agar

Back 24

B : str. pyogenes
A : str pneumoniae
non : ???? WHAT?

Front 25

STREPTOCOCCI
classify according to serological grouping (lancefield)

Back 25

A: str pyogenes
B: str agalactiae

Front 26

STREPTOCOCCI
classify according to biochemical properties?

Back 26

umm?

Front 27

STREPTOCOCCI
diseases

Back 27

tonsilitis, scarlet fever
post str. infection: rh. fever and nephritis

Front 28

STREPTOCOCCI
toxins

Back 28

hemolysins (streptolysin O and S)
streptococcal pyrogenic exotoxins

Front 29

STREPTOCOCCI
DD between O and S streptolysins

Back 29

O -> oxygen labile
S -> non antigenic and oxygen stable

Front 30

STREPTOCOCCI
enzymes?

Back 30

streptokinase
hyalurinidase

Front 31

STREPTOCOCCI
pyogenes classified into types according to

Back 31

M and T antigen (M --> 80 types)

Front 32

STREPTOCOCCI
diseases produced by Str viridans

Back 32

Dental sepsis, dental caries, bact endocarditis

Front 33

STREPTOCOCCI
diseases produced by str agalactia

Back 33

neonatal sepsis and meningitis

Front 34

STREPTOCOCCI
organism with similar morphology and can resist heat

Back 34

Enterococcus faecalis

Front 35

STREPTOCOCCI
organism with similar morphology and can grow on Na?

Back 35

enterococcus faecalis

Front 36

STREPTOCOCCI
antigenic structures of the str. pyogenes capsule?

Back 36

C ag, proteins MTR

Front 37

STREPTOCOCCI
test used in diagnosis of rh fever?

Back 37

ASOT (antistreptolysin O titer)
if >200 ... +ve

Front 38

PNEUMOCOCCI
diseases

Back 38

lobar pneumonia
bronchopneumonia (complications eg pleurisy, empyema, meningitis, arthritis, sinusitis, brain abscess)

Front 39

PNEUMOCOCCI
DD with other organisms (viridans)

Back 39

1. optochin sensitivity
2. bile solubility
3. inulin fermentation
4. virulence in mice

PNEUMOCOCCI +ve for ALL
viridans negative for all

Front 40

PNEUMOCOCCI
typing ?

Back 40

by PLS C ag
by capsule swelling test
(quellung test)

Front 41

PNEUMOCOCCI
prophylaxis

Back 41

polyvalent vaccine

Front 42

PNEUMOCOCCI
species of viridans

Back 42

salivarius, mitis, mutans

Front 43

PNEUMOCOCCI
ttt?

Back 43

penicillin
if resistant -> vancomycin

Front 44

DIPHTHEROIDS
method used to demonstrate granules

Back 44

Neissers stain

Front 45

DIPHTHEROIDS
Toxigenicity tests

Back 45

1- elecks
2- PCR
3- ELISA

Front 46

DIPHTHEROIDS
selective and enriched media?

Back 46

mcleods (K tellurite) and Lofflers serum

Front 47

DIPHTHEROIDS
prophylaxis?

Back 47

1- active immunization by alum ppt toxoid DPT or DT
2- close contacts (AB penicillin or erythromycin) + one dose of DPT or DT >12 M

Front 48

DIPHTHEROIDS
causes of pseudomembrane in throat

Back 48

diptheria, str pyogenes, v ang(???) and Clostridium

Front 49

DIPHTHEROIDS
why would this organism become toxic

Back 49

lysogenic conversion

Front 50

DIPHTHEROIDS
toxin has a special affinity for

Back 50

heart muscles
nerve cells and adrenal cells

while org. prefers throat, conj, wound and vulva

Front 51

DIPHTHEROIDS
how do you test for susceptibility for this organism?

Back 51

schick test

Front 52

DIPHTHEROIDS
ttt

Back 52

big dose of antitoxins (h test) and penicillin

Front 53

DIPHTHEROIDS
dd of this organism and listeria?

Back 53

by motility
listeria motile

Front 54

NESSEIRIA
(smear stains by G and MB. N G film from culture)
identify

Back 54

NAME
SMEAR OR FILM from culture
NAME OF STAIN

Front 55

NEISSERIA
selective media?

Back 55

thayer martin (chocolate + VCN)

Front 56

NEISSERIA
mention ab used for its isolation
or
ab not used in ttt

Back 56

VCN

Front 57

NEISSERIA
dd between path and non path strains

Back 57

NON PATH
- grow on nutrient agar
- dont need excess co2
- can grow at room temp
- colonies are more opaque
- diff fermentation reactions

Front 58

NEISSERIA
2 pathogens

Back 58

neisseria gonorrhea
neisseria meningitidis

Front 59

NEISSERIA
2 diseases

Back 59

gonorrhea and meningitis

Front 60

NEISSERIA
enumerate org diagnosed by smear

Back 60

N, V ang, cand

Front 61

NEISSERIA
why do we culture in acute stage of this disease?

Back 61

confirmation
Ab sensitivity
if there is a medicolegal problem

Front 62

NEISSERIA
drug used for carrier and close contacts of this disease

Back 62

rifampicin

Front 63

NEISSERIA
specimen in carrier

Back 63

nasoph swab by wests swab

Front 64

NEISSERIA
mention the decolorizing agent in this stain

Back 64

Ethyl acohol 95%

Front 65

NEISSERIA
mention 2 genera with the same morph

Back 65

N. and Moraxella

Front 66

NEISSERIA
virulence factors

Back 66

pili, outer membrane proteins, endotoxin(lps), IgA protease

Front 67

SPORE BEARER BACILLI ...

Back 67

with G stain, MZN or NF stain

mzn -> decolorizing agent: sulphuric acid 0.25 - 0.5%

Front 68

SPORE BEARER BACILLI
classification

Back 68

1- aerobic such as
B. anthracis and B cereus (dd by animal path)

2- anaerobic such as
Cl tetani, Cl causing GG, Cl botulinum, Cl difficile

Front 69

SPORE BEARER BACILLI
diseases

Back 69

anthrax, tetanus, GG, botulism

Front 70

SPORE BEARER BACILLI
other spore stains?

Back 70

other two

Front 71

SPORE BEARER BACILLI
mention 3 org with this morphology and produce food poisoning

Back 71

B CEREUS
Cl Botulinum
Cl Perfringens (type a)

Front 72

SPORE BEARER BACILLI
mention the organism with this morphology used in biological warfare

Back 72

B Antrhacis

Front 73

SPORE BEARER BACILLI
2 examples of zoonosis

Back 73

anthrax and listeria

Front 74

SPORE BEARER BACILLI
vaccine and ttt of anthrax

Back 74

alum ppt toxoid and Penicillin

ciprofoxacin for bioterrorism

Front 75

SPORE BEARER BACILLI
mech of action of Cl T toxin

Back 75

inhibits the release of inhibitory mediators (Glycine and GABA) while
Cl B inhibits the release of Acetyl choline

Front 76

SPORE BEARER BACILLI
virulence factors of Clostridium perfringens

Back 76

capsule, toxins (alpha and entero)
enzymes (Hyaluronidase, collagenase, DNase)

Front 77

What is the best specimen in meningitis?

Back 77

CSF
blood
aspiration from skin lesion

Front 78

What is the best specimen in pneumonia?

Back 78

sputum

Front 79

What is the best specimen in endocarditis?

Back 79

blood

Front 80

What is the best specimen in tonsilitis?

Back 80

throat swab

Front 81

What is the best specimen in otitis media?

Back 81

pus

Front 82

What is the best specimen in food poisoning?

Back 82

Food, vomit, stool

Front 83

What is the best specimen in gonorrhea

Back 83

acute: urethral discharge of both sexes

chronic:
male - morning drop or prostatic massage
female: cervical swab

Front 84

peptone water, nutrient broth
uses

Back 84

1. base for other media
2. growth of non fastidious organism

Front 85

soft agar uses?

Back 85

motility test
preservation of org

Front 86

soft agar
conc of agar in media

Back 86

0.7%
(any other agar 2%)

Front 87

deep agar uses

Back 87

1- growth of anaerobic bact

2- test of o2 req of bact:
* st aerobic -> grow at surface only
st. anaerobic -> grow away from surface
facultative anaerobic -> grow all over
microaeroph -> just below the surface

Front 88

nutrient agar plate or slope (to increase surface area of slope)
uses

Back 88

as broth
(3 org not gr: str, path N, C.D.)

Front 89

blood agar
preparation

Back 89

agar 2% is first sterilized in autoclave then we add blood (normally sterile)
at 50* c (blood conc = 5-10%)

Front 90

blood agar uses

Back 90

1- growth of fastidious organism (str)
2- detection of hemolytic activity (alpha such as str v, beta such as staph aureus and str pyogenes)

Front 91

chocolate blood agar (lysed blood agar)
prep

Back 91

as blood agar then we increase temp to 80* for 10 min

Front 92

uses of chocolate agar

Back 92

growth of F org as path. N and haemophilus

Front 93

macconkeys agar
selective or inhibitory agent?

Back 93

sodium taurocholate

Front 94

macconkeys agar
selective for?

Back 94

gram negative bacilli (inhibits gram positive)

Front 95

macconkeys agar
sugar? indicator?

Back 95

lactose
neutral red

Front 96

macconkeys agar
use?

Back 96

DD of intestinal org into LF (pink colony eg e coli) and NLF (pale yellow colonies eg salmonella and shigella)

Front 97

egg saline
solidifying agent?

Back 97

egg

Front 98

egg saline
how do you solidify this media?

Back 98

inspissation

Front 99

egg saline structure?

Back 99

egg yolk and saline (2.5:1)

Front 100

egg saline screw capped to?

Back 100

prevent dryness

Front 101

egg saline uses?

Back 101

enriched media for culture of mycobact tb

Front 102

lofflers serum
solidifying agent?

Back 102

seruum

Front 103

lofflers serum
structure

Back 103

serum + glucose broth (3:1)

Front 104

lofflers serum
uses?

Back 104

enriched media for culture and typical morphology of C diptheria

Front 105

sugar media (comment on result)

Back 105

no fermentation: CT

F with acid: NM , NG

F with AG: EF and CL P

Front 106

sugar media
base

Back 106

peptone water

Front 107

sugar media sugar percent

Back 107

1%

Front 108

sugar media
mention the indicator

Back 108

phenol red

Front 109

sugar media
importance of durhams tube

Back 109

to trap gas

Front 110

TCBS (thisulphate citrate bile salt)
ph?

Back 110

8-8.6

Front 111

TCBS
sugar?

Back 111

sucrose

Front 112

TCBS
indicator?

Back 112

bromothymol blue

Front 113

TCBS
selective agent?

Back 113

TCB
thiosulphate citrate bile

Front 114

TCBS
uses

Back 114

selective media for Vibrio cholerae

Front 115

TCBS
mention 2 org grow on this media

Back 115

v ch(yellow) and v parahemolyticus(blue)

Front 116

LJ M (beaten eggs + mineral salts + malachite green)
selective media for?

Back 116

mycobact (2-8 w)

Front 117

LJM selective agents?

Back 117

malachite green and glycerol or pyruvate

Front 118

cooked meat broth ..

Back 118

strict anaerobic media as meat contains reducing sub (blood pigments of meat and unsaturated fatty acids)

Front 119

cooked meat broth for culture of?

Back 119

strict anaerobic org such as CL (T, B, GG) and peptostreptococci

Front 120

cooked meat
other anaerobic media?

Back 120

thyoglycolate broth

Front 121

selenite f broth
favors growth of?

Back 121

Salmonella TYPHI and parathypi
but disfavors growth of E coli

Front 122

blood culture bottle
how do u take a specimen

Back 122

vein puncture after skin dis by 2% tr iodine or betadine

(broth + 0.05% sodium sulphonate (anticoag))

Front 123

blood culture bottle
mention 3 org grow on it

Back 123

str pn
str v
NM

Front 124

media types

Back 124

check paper

Front 125

sterilization of media

Back 125

check paper

Front 126

advantages of solid media

Back 126

separate colony
quantity
morph of colony

Front 127

disadvantages of solid media

Back 127

small number

Front 128

STAPHYLOCOCCUS AUREUS COLONIES
on n agar

Back 128

golden yellow colony

Front 129

STAPHYLOCOCCUS AUREUS COLONIES
on mannitol salt agar

Back 129

yellow colonies (yellow and pink)

Front 130

STAPHYLOCOCCUS AUREUS COLONIES
on blood agar

Back 130

beta hemolytic (as str but larger and white)

Front 131

STAPHYLOCOCCUS AUREUS COLONIES
novobiocin sensitivity test
how do u DD by another method?

Back 131

um?

Front 132

STAPHYLOCOCCUS AUREUS COLONIES
phage typing
other methods of typing

Back 132

ab and ab s

Front 133

phage typing principle

Back 133

st aureus cultured on agar plate, 23 phage are dropped on the plate, each in its marked area... incubation 24 h... the type of strain is designated by phages that lyse it

Front 134

phage typing significance

Back 134

to trace the source of infection in the epidemic disease

Front 135

phage typing
org we do this technique

Back 135

staph aureus epidemic

Front 136

STREPTOCOCCUS COLONIES
on blood agar

Back 136

beta hemolyitic (clear zone around pin point translucent colonies)
alpha hemolytic (colonies surrounded by greenish zone)

Front 137

STREPTOCOCCUS COLONIES
optochin test

Back 137

sensitive: str p (gr A)

resistant: BHS other than gr A

Front 138

STREPTOCOCCUS COLONIES
heat resistance test (e fecalis, if growth in 4 quarters)

principle

Back 138

EF resist heat at 60* for 30 mins
so grow in 4 q

Front 139

heat resistance test
mention diseases produced by this org?

Back 139

UTI
endocord
biliary TI

Front 140

indicators of fecal pollution of h20

Back 140

e coli
cl p
e f

Front 141

STREPTOCOCCUS COLONIES
e fecalis

Back 141

it may produce alpha , beta or gamma h

it can grow on ord m and mac , resist heat 60 c 30 min, salt 6.5%

Front 142

disc diffusion method
other metho

Back 142

tube dilution

Front 143

disc diffusion method
define the disc

Back 143

filter paper containing certain conc of one ab

Front 144

disc diffusion method
mention the sensitive and resistant drug in front of you or what are the recommended ab for ur patient

Back 144

duh

Front 145

disc diffusion method mention the conc of bact used

Back 145

10^8 /ml

Front 146

disc diffusion method
enumerate ab acting on
cw
ptn
na

Back 146

CW: penicillin, bacitracin, cephalosporin

PTN: aminoglycosides, T and chloramphenicol

NA: rifampicin , quinolone, nalidixic acid

Front 147

tube dilution test:
used for determination of

Back 147

MIC

Front 148

tube dilution test:
value of mic.. read it
principle:

Back 148

we do 2 folds dilutions of the tested ab in sterile broth then we culture the organism (10^5 /ml) and one tube cont no ab..... incubation.... we examine the tubes for turbidity

(T= bact growth not inhibited by this conc of antibiotics)

Front 149

mbc

Back 149

is the least conc of ab (ug/ml) that totally kill the bacterium being tested (it is used in in immunocomp pt and in prolonged therapy) bit in patient with normal immunity or short therapy, MIC is sufficient.

Front 150

how do u know it is cidal or static

Back 150

by subculture after MIC... growth... static
no growth.. c (mbc)

Front 151

CFT result?

Back 151

+ve NoH ( Button like) -ve (hemolysis)

Front 152

CFT
organism diagnosed by this test

Back 152

TP, CH, rick, Viruses

Front 153

CFT indicator system?

Back 153

sensitized sheep rbcs (rbcs + its AB) = IS

Front 154

CFT principle:

Back 154

according to the test infront of u

CHECK PICTURES

Front 155

ELISA
mention the result

Back 155

colored wells: +ve
colorless wells: -ve

Front 156

ELISA
org diagnosed by this method

Back 156

hepatitis, AIDS, herpes and TB

Front 157

elisa...
check papers for bunch of stuff

Back 157

..

Front 158

widal rack (widal test)
use

Back 158

diagnosis of enteric fever either T or PT and diagnosis of brucellosis by determination of antibody titer (last tube shows agglutination)

Front 159

widal rack
principle

Back 159

semiquantative tube agg test (serial dilutions of the patient serum + known antigen in a fixed amount)

Front 160

widal rack
coaggulation test

Back 160

depends on ptn a of st a as in meningitis or NG

Front 161

widal rack
latex agg test

Back 161

latex beads coated with ab to solutble ag eg capsule for its detection as in meningitis

Front 162

single radial diffusion
use

Back 162

estimation of diff Ig classes in serum eg IgG

Front 163

single radial diffusion
principle

Back 163

UK Ag (serum) in well and K Ab (anti Ig) incorporated in agar --> ppt ring (+ve result)

Front 164

single radial diffusion
other ppt methods

Back 164

double ID as in eleks and V Ag detection, RPR and VDRL

Front 165

Seitz filter
type of disc/filtering surface

Back 165

asbestos filter

Front 166

seitz filter
method of sterilizaiton

Back 166

autoclave

Front 167

seitz filter uses

Back 167

preparation of bact exotoxin
sterilization of fuild culture media which doesnt stand heat eg sugar m and heat labile biological fluids as serum and antibiotics

Front 168

syringe filter
sterilization

Back 168

by ionizing radiation and used as a (small volumes)

Front 169

syringe filter

Back 169

membrane filter, made from cellulose nitrate (adv: its pore size is controllable)

Front 170

sintered glass filter

Back 170

ground glass filter

Front 171

why glass

Back 171

glass is intert

Front 172

sintered glass filter
sterilization

Back 172

oven 160-170 c for 1 h

Front 173

sintered glass filter
uses

Back 173

as a ????????????????

Front 174

candle jar CO2 for

Back 174

campylobacter
brucella abortus
some haemoph
path N

Front 175

Anaerobic jar (gas pack) for

Back 175

strict anaerobic org eg cl and bacteroids and peptostr

Front 176

anaerobic jar
indicator

Back 176

methylene blue soaked paper in alumm packet

Front 177

anaerobic jar
catalyst used

Back 177

palladinized aluminium pellets

Front 178

anaerobic jar
mention m replace it

Back 178

cmb

Front 179

sterile container for urine or sputum
org?

Back 179

pneumonae (str pn, st aureus and TB)

Front 180

sterile tube (cotton... oven) ( black cover... autoclave)
uses

Back 180

collection of urine/pus/csf

Front 181

sterile swab
sterilization?

Back 181

ionizing radiation

Front 182

sterile swab uses

Back 182

rectal vaginal wound and throat swabs

Front 183

sterile swab org

Back 183

conjucitivitis : NG and st aureus

Front 184

sterile disposable syringe

sterilization:

Back 184

ionizing radiation or ethylene oxide gas

Front 185

skin disinfection

Back 185

1% iodine in 70% alcohol

Front 186

sterile disposable syringe used also for

Back 186

aspiration of blood, pleural fluid, joint fluid, or ascitic fluid

Front 187

organisms producing meningitis

Back 187

n meng
str pneumonae

Front 188

neonatal m:

Back 188

listeria and str agalactia

Front 189

tissue culture bottle
types of tcl

Back 189

1ry (mnokey k)
semicont(fibroblastic cell)
cont (hela , hep2)

Front 190

virus growth is recognized by

Back 190

CPE
haemadd
haemagg
F for interference

Front 191

types of CPE (or cellular changes)

Back 191

rounding, ballooning, synctia

Front 192

other methods for virus isolation

Back 192

chick embryo and lab animal

Front 193

methods for direct detection of v

Back 193

EM, IF, ELISA, NA PROBE, PCR

Front 194

indirect detection of v

Back 194

serology

Front 195

autoclave
temp and time

Back 195

121 for 20-30 mins

Front 196

autoclave principle

Back 196

steam under pressure

Front 197

autoclave
uses

Back 197

sterilization of all surgical instrumetns
sterilization of culture med that withstands heat eg agar (or ? choose media not str by autoclave)
sterilization of glassware with rubber liner

Front 198

tests for efficiency

Back 198

biological indicator by using resistant bact endospore
chemical indicator by tapes which change color with temp
mechanical indicator which rcords the temp and pressure

Front 199

hot air oven principle

Back 199

it is the main method of dry heat with temp 160 -170 for 1-2 h

Front 200

uses

Back 200

str of glassware
str of oil and powders
str of steel instruments