Unit 16
Culturing Microorganisms
Assignment C&D
Within this assignment, I will be discussing the different biocontainment methods and how
they are used within different lab settings, the different preparations of bacterial plates and
their effectiveness, as well as discussing and evaluating my own practical work of cultivating
bacterias.
The different biocontainment levels
Biocontainment is defined as the tools and equipment needed when working with
microorganisms for disease not to spread.
Biosafety Levels PPE required Types of The Handling of
Bacteria Microorganisms
1 - Within biosafety level Usual PPE such E.coli 1. Use aseptic
one, low-risk as gloves, Bacillus subtilis workspaces by cleaning
microorganisms are goggles and lab desks etc. with alcohol.
usually used, this is coats. 2. No food or drink
when they usually have should be present.
no high risk of infection. 3. Regular hand
(1) washing after handling
This is the level usually microorganisms.
seen within 4. After spillage,
school/college laboratory decontamination of
settings. surfaces should be
instant.
2 - These are labs where PPE such as lab HIV 1. Correct PPE must be
infectious to human coats, gloves Staphylococcus worn at all times.
diseases are handled, and goggles, aureus 2. A biological safety
and can pose a health face shields may Strains of cabinet may be used if
risk. The personnel in the also be used. salmonella sprays etc. are present.
lab have specialist 3. Doors that are
training in order to be lockable so the
able to handle the microorganism can’t
pathogens. spread through the air
This is more restrictive and infect other people.
than level 1, and 4. Aseptic work
personnel not working in environment.
the lab cannot enter the
lab whilst
microorganisms are
being handled.
3 - This involves PPE such as Yellow fever 1. Ventilators are
microorganisms that are goggles and Anthrax present to circulate
at risk of killing if inhaled. gloves. Tuberculosis clean air throughout the
They can be Respirators and room.
microorganisms not local full 2. There is double-door
, to the lab area. gowns/scrubs access through the labs.
This is even more are worn. 3. Negative pressure
restricted than Biosafety rooms can be used, this
level 1 and 2, through the means the air within the
use of government room is at a lower
agencies to handle the pressure than that of
microorganisms. outside, this means
Vaccines may have to be dangerous particles will
used in order to work not flow outside the
with these microbes to room when a door is
ensure that the risk of opened.
death is limited. 4. Biosafety cabinet
used.
5. PPE worn correctly.
6. Eye wash and hand
wash stations at all
exits.
4 - These are labs that PPE is worn, as Ebola 1. Personnel have to
contain microorganisms well as a full set Marburg virus shower before leaving
that are lethal to the of extra clothes. the lab/centre.
public but are yet to have Gloves, goggles 2. A level 3 biosafety
effective treatments. If and lab coats cabinet must be used
these got out to the are worn as well for all airborne
public it would cause an as a full-body organisms.
epidemic/pandemic. This suit which has 3. A plan that is written
is compared to all other positive pressure down must be followed
levels which do have - where air is to ensure no
treatments for the forced out of the contamination.
diseases. suit.
Within our laboratory, we used biosafety level 1 equipment, meaning we wore PPE such as
gloves, goggles and lab coats and ensured we used aseptic technique to prevent
contamination. This is important because it means no illnesses or spreading of bacteria will
happen. Without the appropriate methods of biosafety, several infectious diseases could
spread and cause fatalities, such as if gloves weren’t worn, the microorganism may be
ingested.
Biosafety cabinets
I Level one biosafety cabinets E.coli
are used for school/college Mould
laboratory settings. It Animal and plant tissues
involves the low-risk
pathogens. Within these
cabinets, a HEPA filter to
filter the harmful air before it
is removed from the cabinet.
It ensures that any harmful
pathogens are removed
, from the work surfaces etc.
(2)
II These biosafety cabinets Influenza
can be classified into types, Tuberculosis
such as type A1, A2, B1 and
C1. They are used for
moderate risk pathogens
and also involve a HEPA
filter. It removes any
contaminated air generated
by pathogens, which then
circulate throughout a lab.
These are used in places
such as hospitals, and
biomedical labs.
III These are used for working Ebola
with highly hazardous Mycoplasma pneumoniae
pathogens. It is enclosed, Species of Brucella
and has spaces for handling
the organisms with gloves. It
uses double HEPA filters in
order to filter air as well as
being run through a
chemical decontamination
system. These are used
often in isolated labs.
Biosafety cabinets are effective in reducing inhalation risks of harmful bacteria through the
filtration of air and protection of surfaces. Without biosafety cabinets, pathogens that can be
lethal if inhaled such as ebola, may have a higher risk of being inhaled by those working in a
lab and being spread.
Microbiology Techniques
Aseptic method is incredibly important for ensuring no contamination of specimens, this is
because aseptic methods ensure an area/worktop is completely sterilised before and after
use. It involves using a cotton ball/swab, and alcohol and placing it around the whole area of
the desk one will be working on (this includes the sides of the tables). Without an aseptic
method, cross contamination may happen between different bacterias, or bacteria may
remain on a surface after use, leading to accidental ingestion from another individual,
leading to illness. This applies to our laboratory biosafety level 1 environment, as well as the
use of PPE.
Lawn-Spreading
Lawn-spreading involves spreading bacteria within a circular motion across an agar plate.
This ensures equal coverage of bacteria across an entire plate. It is particularly effective if
one wants to count colonies, or work out effects on an inhibitor such as antibiotics due to the
even spread.