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Blood. Cu ltu re
~ l t u r e is the€ingle most important pro ced ue to bacteria.
~to _d_et_e_Jc~ - -
Q. Wha t are the indications of blood culture? 211/M 141 SU 121u 081u/l, RU-20M)
Q. Mention 4/5 important indications of blood(DU- (DU ;U-151u)
Q. Nam e 6 diseases where blood culture is need
culture. -081 ) J
ed. (DU-071, C -081
Ans.
~t ion of blood culture:
Enteric fever
Infective endocarditis
Meningitis
Septicemia
Bacteremia
~ -Py rexia of unknown origin
Osteomyelitis \
X-_,_Pyelonephritis
• • ....Pneumonia
. Pyae mia
~1-n ruce llosi s
lague • • \ .; .
Peritonitis
·tis . .. . J
\

. ..._ . ' \ '\

media, used fo~ blood culture? (DU-03J)

organisms:
tica-soya broth
ile bfoth '-
ra1n heart infusion broth )
Glucose broth '' \ '
'
Colombia broth 1
\
For anaerobic organisms:
W Thioglycate broth _,
I ' \ \

Brai n heart infusion broth with cooked mea y. ,

). 1
1 1 •
1
-~,

_...Q:--'What is the ~d ur e of blood _ s

o ~ for ~lood culture in a laborato
P ry? (DU-tiJ, SU-
Ans.
15Ju,12/10/07Ju)
2-c 0-$: 7

~ll ec tio n procedure for blood culture ~ , I•

1
- Bloo d is collected with §_trict aseptic technique.
~- Apply a .!._oumiquet and locate a fixed vein .. .
by touch. Release the tourniquet while the skin
prepared. is beinl
The venipuncture site should be disinfected with --- --= =- =- - .
<fryidone iodine and al~ Du rin g disinfectio
the venipuncture site and cleanse the skin in n, start at
concentric circles of1n crea sing dia me ter
antiseptic preparation to dry for at least 30 seco .~
ds. Do not touc h the skin after it has be
Reapp y t e ourruquet, e orm venipunctur and d.
(for adults) withdraw approximateI 20
~ d d the bloo d to labele aero 1c an anae
ro ic blood culture bott es. ood-
~ T ~ e specimens to the laboratory progtptly
, or place them in an incubator at 37°c .
(Ref Jawetz 's·28th)
 731
What are th recautions or pre-requisite fo collection of bloo for culture?. Clinical Microbiology
Q• I T -----~,;;;;:.:,:~~~~ ' "'
j\ns . .
r'
' , , ), • ,
•,..,ntions or re-re u1s1tes for collection of blood for It -- -- ____
_rrec"~ , bl d b cu ure
• ----

1 Patient s oo must e co1lecte e initiation of tib" .

. . or 1·r the patient
• ant1·b1ot1c,
• • blood must b e co11ecte 4 hours
after sto an
a iotic
f .thera ' · is alread,
- /4Iood should be taken when there i nse o tempera pp ge o antibiotics. Y-on
V D ·r
It is best 1
tw bl d ure r pea o temperature
o oo samples are taken at two di erent times D . .. •
, ,.
4~trict ase_p!ig measures should be taken during collect. d -~r getting positive culture. _.
~ediate inoculation of patient's blood into the cul:::.n an diproc_e~u~e of blood culture. _
1
_6/Blood is ne~er sent_ to the laboratory in a syringe or :t:~e ~e: ~~ee ~e~p ?f anotl;ter ~ew ne~c%-
c~re media at patient's bedside:, • ._t is inoculated unmediately ~o
7 ')
Q. Enumerate different methods of blood culture. (DU-07])
Ans.
Dif iiitmethods of blood culture: Blood culture can be done n three rocesses:
if"1raditional method: U sin Ii uid media on b1p as1c media.
v2~ytic method: After processing in lytic so utton in so 1 me ia.
Automated: Very rapid (within 6~~)-.- - - - - - -
"\
Q. Describe the procedure of blood culture. (DU-05M, CU-1 0Ju, SU-09J,08Ju/J)
Ans.
Procedure of blood culture
• Traditi)>tlpi~ ethod:
. S blood is collected aseptically & is inoculated directl
ood: Medium is 1:10. -----------~~== ===----
~The inoculated media is then incubated at 376C
~ e growth of bacteria in the broth is determine r 1dity of the broth When the medium becomes
turbid, a few drops of broth is then inoculated asepticallY. in s • • e MacConke a ar.
~Bacteria in agar medium are then identified by observing the colony morphology & biochemical
c~acteristi7

Blood culture on solid medium by Iytic method: H_...-e, collected bloo~ is introduced in lytic flui which is
__
.......__centrifuged and the deposit is then inoculated • 3 - 5
then

\Aut~fed blood culture: This is an automated device where the bacterial growth is determined by
~nnination of metabolites of the bacteria automatically, instantly when it is produced.

Q. How will you id~ntify organisms after blood culture?

Ans.
1
~fication of or anisms after blood culture: By- . ..
(1). Gram staining )

(2. Motility test:

\.... a. Hanging drop preparation.
"- b. Inoculation to soft agar. /
': c. Inoculation to MIU media (motility Indole and Urease).
Biochemical test:
Catalase test.
4. F1~nI:- c¢}dase test follqwed by inoculat!onhint~ TSIItemstesd1a·ag.glutination test and type specific anti-sera.
a species identification is done b~t~b~io~c~e~m~1~c~a~~~' - ~ ~ = = = : . . : . - - - - - - - - ' - - - - : . : _ _ __ _ _ _ __

~_____--:--
 - -
·- -

Blueprint Mi 732
ed in the blood culture? .. ,r..P '--
Q. What are ,;t'"''\?,V""- \
Ans. ____
t..P'--
E . e
~~=- =~~~ ~:!!! !;:Y: JJ~~ ~~u! !!li!tu~r
i:::::: s~r-- =n";n ~~PS ) ~ r c i a l name- liquoi
d) ,'
•Sodium

~l Function:
-a-. Prevents blood clotting.
-. -
---8;-. Inhibits complements,.lysozymes and phagocytes.
.._.._._,~

-C:- Counteracts aminoglycoside antibiotics.

· $--p lactamase: To counteract pen· • • of drugs.
~nt ibio tic a rbent regam,

--
7N, RU-13Ju, SU-03S)
Q. Write short note on: Blood culture. (CU-20M,19M,l
culture from above.
Ans. Write in short Indication, Media and Methods ofblood

. Why blood is directly inoculated in the medium?

{
•·• ·- ··
B~i rec tly inoculated in the medium, because-
are added . So blood will clot in short time. Bacteria will be trapp ed in the clot andfall
anticoa~lants . .. - - .
to grow in the medium;) e the possib ility of contamination;.
h. So to reduc
-2:-- Blood itselfis a very enriched medium for bacterial growt _,,
jt is also~tl y inoculated in the medium_:_.)
blood culture? ' ....
Viv@ Why anti-coagulant is not added in the bloodfor res with the. growt h· of the
culture,. becau se it interfe
Ans. Anti-coagulant is not ad!fed in the blood for blood
bacteria in the medium.~ • - -•...,_ _ . . •
e? • • _ - • .
P'iva Q. Why l,qu,d me ium is used in· blood cultur
Ans. . . - . - - - - -- -
is used in blood culture
um siz~ is large.
acConkey agar media, if5 ml?lo od is
...,
-~ak:n:
.
~tl!:!~e will over-floodin ·1 /
ty 10 ml ofblood is not required?
. Beca~se it is the ~astage ofblood and media, -)

Q. Write short note on: Septicemia.

Ans.
t~cemia-i_ • • with signs and symptoms caused by
g orgams

s· gs & symptoms (V

~Tem pera ture> 38 °C or< 36 °C. . .~t \1/

~Pu lse rate > 90 beats per minute. -\
rate > 20 per minut e. :ll
,..
~Res pirat ory
4:-1> C02 < 4.3 kPa (32.5 mmHg).
3
~ite blood _cell count > 12,QQ0/mm or< 4,000/mm3.
Evidence of mfection. -
(Ref Davidson 's-2J1'/300)
Sepsis largely Its from host responses to icrobial Ii opolysaccharide, pepti dogly ~
n~ and t er , .
lipoproteins or superantige mfectious e ~ .
~~------- (Ref Davidson 's-21''/300)
 733
• Clinical Microbiology
rl~~ t• -
n·
f • .c. • • kn
prunary: ~urce o 1n~ectio~ 1s ~ot own. I
secondary: Source of 1nfect1on 1s present, eg,
;-· GIT
Hepato-biliary tract
Genito-urinary tracts particularly pelvic org~
Respirato1:17 tract. . .
Skin, particularly wound 1nfect1ons, etc.
' \

.. -- .
susceptible individuals \.
/ . Very youn~ and very old. . . . . . . • . . .
Patients with DM, hematological mahgnanc1es, disease of gen1to-unnary, hepato-b1hary, intestinal tracts
• aruiAID~ '
---~Y ', ..... - •• - ·-·--- - __: (Ref: Davidson's-2JS'l301)
,.
Cau~of sepsis
1J' Bacterial taph. aureus
.,
~rep. pneumoniae
Other streptococci
taphylococcal or streptococcal toxic shock syndrome
• Enterococci •',
• Neisseria meningitidis
E. coli, other Gram-negative bacteria I •

seudomonas aeruginosa
Yersinia pestis
C. difficile , . _
olymicrobial infection with Gram-negatives and anaerobes)_
M cobacterium tuberculosis, M. avium com lex MAC
Fungal ~didaspp.
zsto lasma ca sulatu.-111, other <limo
Parasitic rum malaria ~-,
microti •..'
lJid.es stJ;coralis h erinfe~t~ drome
(Ref· Davidson 's-21 s'l301)

Nice to know
Se ·e-ii(ock: Septic shock describes s sis plus hypotensio (systolic blood pressure < 90 or a fall of> r;/o'

-
mn:zHg from baselifl.£!.!!_at is not responszv!!.__ uz c a enge or due to anot er cause . _t piay _iJymulll=organ-
.fatiw.e and requires intensive care unit admission. j)

c: )-~
'---- "':,----...--------~- (Ref: D'!vidson 's-2 JS'/300)

Q. What is bacteremia?
Ans. ,
~cteremia: Presence o viable bacteria in blood without any symptomatology is called bacteremia.)

lyp~: --=--=--==--=- . •
0· Iransient: Lasts fo~utes t~and dissolve spontaneously without consequences.
_ :.
Causes: -======~==--~
~>-.:::::==
A. Pneumonia
A. Meningitis 7
-s; -~
A. Pyelonephritis •\ /
,..A. Septic arthritis •
\
I
~( 734
Blueprint Microbiology '-l
Intermittem:
• X Enteric fever ..
-r, Infective endocard1t1s
Brucellosis
/ Contin~ous: occurrence, cle~e and re~enc e in th~am~ tient by th:_J am~·~
Ca';s.RT I t}f • •• • •
,,UTI ~:
..... / ••••• -
·-- ... .. _ ~· .__ .... _

..-J:-- Intra-abdominal abscess. . ,.

I i '
Q. Enumerate the organisms responsible for bacteremia. (C
\

Ans.
Pathogens causing bacteremia
Gram +ve bacteria Gram -ve bacteria , -"
• Staphylococcus aureus Salmonella .., ,
:, • Streptococcus pyogens Briiceii a '7 • ,I
, ' • .••.
CL • Streptococcus pneumoniae
• Streptococcus viridans ;:::: 1a;:i~p~i~us irJ1ue15~e ~)<J~'/: .
y Enterococci ..._ Pseudomonas aeruginosa
Anaerobic streptococci • Proteus •
' .
Clostridium perfringens Bacteroides
isseria meningitidis'
• Yersinia pestis
ebsiella neumoniae

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