The document provides guidelines for properly collecting blood cultures to detect bacteraemia or fungemia. It stresses the importance of using sterile technique and optimal skin antisepsis to minimize contamination. Multiple blood cultures, each with large volumes of blood, should be taken from separate sites prior to antibiotic therapy to detect low-level bacteraemia. Careful venipuncture technique and allowing antiseptics to fully dry are critical to obtaining uncontaminated cultures and making accurate diagnoses.

1. COLLECTING BLOOD FOR CULTURING - POINT CARE PROTOCOL
Physicians order the blood for culturing when the patient’s condition needs evaluate whether there
is bacteraemia and septicaemia. Many times in developing countries the specimens are collected
without any of point care and aseptic precautions, Many blood cultures turn out to be either sterile
when inappropriate specimen is inoculated and contaminated when careless in collection persists
Circumstances in which blood cultures are especially important include known or suspected sepsis,
meningitis, osteomyelitis, arthritis, endocarditis, peritonitis, pneumonia, and fever of unknown
origin. Blood is one of the most important specimens received by the microbiology laboratory for
culture, and culture of blood is the most sensitive method for detection of bacteraemia or fungemia.
Issues related to types of bacteraemia, indications, and technique for blood cultures will be
reviewed here for bringing in scientific spirit in newer generation of Microbiologists Next question
comes who will collect the blood, it is certainly trained phlebotomist, with constrains in man power
the specimen should be collected at least by the trained nurses with skills however in many teaching
hospital the matters are left to least trained nurses, are even nursing Students However the rate of
contamination will reflect how poor is the system we work, The quality of the specimens submitted
to the microbiology laboratory is critical for optimal specimen evaluation. In general, adult patients
with bacteraemia are likely to have low quantities of bacteria in the blood, even in the setting of
severe clinical symptoms. In addition, bacteraemia in adults is generally intermittent. The first step
in appropriate collection remain with optimal collection with ideal antiseptic precaution try using the
standard decontamination adopting if appropriate, decontaminate the skin surface. Use 70-95%
alcohol and 2% chlorhexidine or 1-2% tincture of iodine (TIO) in the modern concept use Betadine to
prepare the site. Allow a contact time of two minutes to maximize the antiseptic effect. For this
reason, multiple blood cultures, each containing large volumes of blood, are required to detect
bacteraemia. Prior to initiation of antimicrobial therapy, at least two sets of blood cultures taken
from separate venipuncture sites should be obtained. The technique, number of cultures, and
volume of blood are more important factors for detection of bacteraemia than timing of culture
collection; these are discussed further in the following sections.
Technique — Careful technique is critical to avoid contamination of the blood culture media by
normal skin flora during the process of collection. This is important because normal bacterial skin
flora can also cause systemic disease, such as infective endocarditis, eg Staphylococcus) and in some
circumstances blood culture contamination can make it difficult to distinguish between false-positive
results and true infection. Measures to reduce contamination include effective disinfection of the
venipuncture site and avoiding blood culture collection through existing intravenous line, which
certainly hampers the optimal decisions whether it is a contaminant or true pathogen
Apply tourniquet to the extremity and identify the phlebotomy site.
Preferred: Use Chloraprep® or locally available chlorhexidine solution
i) Cleanse and scrub the site with 2-3 alcohol swabs. Allow it to dry for at least 30 seconds.
ii) Wear sterile gloves.
iii) Use a firm scrubbing motion for 30 seconds to disinfect the site.
iv) A 10 cm area of the skin should be disinfected.

2. V) Allow the site to dry at least 30 seconds before venipuncture.
Povidone-iodine swabs permit more decontamination than either chlorhexidine alone.
Allow to dry for a at least 30 seconds to allow antiseptic effect
i If using iodine product, clean patient's skin with alcohol to remove excess iodine (to prevent iodine
burns).
ii) Use alcohol pad to cleanse the patient's skin, using a circular motion starting at the site and
moving outward.
iii) Repeat times two.
iv) Allow to dry at least 30 seconds.
Do not touch the venipuncture site after skin preparation. If palpation is absolutely necessary, sterile
gloves must be applied immediately prior to palpation.
Insert needle into vein and withdraw appropriate amount of blood. Draw blood cultures prior to
drawing other blood samples.
a) Insert the needle into the vein
b) Try to keep the dominant hand sterile.
c) Remove the alcohol pad from the top of the culture bottles
d) Attach the vacutainer to the blood culture bottle and inoculate each culture bottle with exactly 8-
10 ml of blood, using previously marked indicator line. If less than 10 ml of blood was obtained,
inoculate aerobic bottle with total amount obtained. A lesser amount can be considered when
talking the blood specimens from infants and younger children
e) Remove the tourniquet and butterfly needle from the site and cover with gauze dressing. Apply
pressure to site as needed.
10) If absolutely necessary to draw from a central catheter site, utilize the site that has been most
recently inserted (unless ruling out catheter sepsis). a) Label the culture bottles with a label in the
presence of the patient. Indicate the time that the specimen was obtained.
b) Do not place label over bar-coded area of the bottle. If you are using BacTec or BD automated
systems.
a) Label the culture bottles with the patient’s name and history number in the presence of the
patient. Indicate the time that the specimen was obtained.
b) Fill out Microbiology-routine lab slip.
c) Indicate the site from which blood was collected using comment section. If using a VAD to draw
the culture, you must indicate type and site of VAD in the comments section (eg. left subclavian
triple lumen).
d) Indicate suspected diagnosis, if necessary (required for rule out endocarditis).
e) Include date and time of collection.
f) Document that cultures were obtained on appropriate nursing form

3. Send specimens to the laboratory as soon as possible. Never refrigerate blood culture specimens.
Send specimens directly to the Microbiology Lab.
Send second set of blood cultures using the same procedure as above. If a different peripheral site is
possible, the second set may be drawn immediately. If using the same site, wait at least 10 minutes
for the second set, and if possible (i.e. not waiting to give antibiotics) draw a third set 1-3 hours
later.
Ref Johns Hopkins Medical Microbiology Specimen Collection Guidelines – Updated 6/2015
I wish all the young Microbiologists to read the article in full details to improve the scientific spirit in
Diagnostic Microbiology
I am thankful to Mr Sreenath MSc my former colleague and a Present Research scholar at All India
Institute of Medical Sciences New Delhi for inspiring me to write as freelancer
Dr.T.V.Rao MD Professor of Microbiology Freelance writer