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[ Facts
about Anthrax ] [ Surveillance
Guidelines in Response to Anthrax Threats ]
[ Laboratory
Safety Guidelines for Handling Suspected Anthrax Samples
]
[ Anthrax
Fact Sheet for Physicians ] [ How
to Handle Anthrax Threats ]
Laboratory Safety
Guidelines for handling suspected
Anthrax
samples
[ D R A F T ]
All testing procedures must be performed within a certified
Class II biological safety cabinet (BSC).
When handling the Bioterrorism agent, white powder the following should be
implemented:
 | The use of respirators which filter >90% of particles ranging from
0.5 um to 1.0 um e.g. N95 respirators from 3M. |
 | Safety glasses or eye shields are recommended |
 | Laboratory coats |
 | Gloves |
 | Cover the work surface with absorbent material that is saturated with
disinfectant
(1:10 bleach) |
 | The blower of the BSC should not be turned on until the powder is
suspended in sterile water and the work area decontaminated of any spilled
powder. This will avoid any dispersal of the powder. |
 | Ensure that the cabinet does not contain any unnecessary items that will
interfere with the airflow. |
 | Any activities that bring hands into contact with mucosal surfaces such
as eating, drinking, smoking and applying make-up are prohibited in the
laboratory. |
 | Protective clothing must not be worn outside the work area and must be
placed in separate containers or laundry bags and autoclaved before being
washed or discarded. Under no circumstances must protective clothing be
taken home to be laundered. |
 | Proper hand washing is required before leaving the laboratory. |
 | Anthrax vaccination is not required. |
Decontamination
- Commercially available household bleach solution containing 5.25%
hypochlorite, when diluted 1:10 is effective in routine decontamination of
surfaces and instruments after working with B. anthracis.
- Contaminated items such as pipettes, disposable loops etc. should be
immersed in decontamination solution until autoclaving.
- Spills involving fresh cultures or samples known to have low
concentrations of the organism should be flooded with decontamination
solution and soaked for 5 minutes before clean up.
- Spills that involve samples with high concentrations of the organism,
organic matter, or occur in areas of lower than room temperature
(refrigerators, freezers) should be exposed to decontamination solution for
at least one hour before clean up.
- Persons involved in the clean up of spills should wear gloves, safety
glasses, and a laboratory coat or gown during the clean up process.
- Respiratory protection should be considered for spills in which a
substantial aerosolization is suspected when handling the powder.
Waste Disposal
- All infectious waste must be placed in autoclavable pans or bags for
decontamination.
- Disinfectant solution must be placed in discard pans so as to begin the
decontamination process.
- All infectious waste must be autoclaved and / or incinerated before
disposal
- Waste should be autoclaved as close to the point of generation as
possible.
- Biological indicators must be used to monitor the effectiveness of the
autoclaving process. Waste may also be autoclaved centrally (away from the
lab) however, it must be packaged in leakproof bags and containers and
must be properly transported to the central autoclave.
- After autoclaving, ideally, all waste should be incinerated for complete
destruction.
- All waste handlers must be properly trained to handle infectious
laboratory waste.
Transportation of specimens
Laboratories that do not have the facilities to perform the testing should
contact CAREC for further information.
Specimens that are to be transported on land must be packaged so as to fully
contain the specimen while in transit.
The triple packaging system must be used.
- The primary receptacle. The specimen must be placed in a leakproof primary
receptacle. If the specimen is a powder in an envelope, place this envelope
in a zip lock bag.
- The secondary receptacle. This is a durable secondary container that
encloses and protects the primary receptacle. If the specimen is a liquid
there must be sufficient absorbent material between the primary and
secondary receptacles to absorb the entire contents of the primary
receptacle.
- The outer package. The secondary receptacle must be placed in an outer
package that protects it from physical damage.
Specimens that are to be transported by air must be shipped as
"Infectious substance, affecting humans" of "Infectious
substance, affecting animals" and packaged in accordance with the
International Air Transportation Association, Dangerous Goods Regulations.
OR
Refer to the WHO "Guidelines for the Safe Transport of Infectious
Substances and Diagnostic Specimens" www.who.int/emc/biosafety.html
Laboratory Procedures for the Identification of
Bacillus
anthracis
Specimen Type:
| White powder
|
Bioterrorism agent
|
Blood
(collected in blood culture bottles)
|
Inhalation /pneumonic disease
|
| CSF
|
Inhalation /pneumonic disease
|
| Sputum
|
Inhalation /pneumonic disease
|
Swab/aspirate of cutaneous lesion or vesicular fluid
(collect in ordinary bacteriology transport medium ) |
Cutaneous disease:
Gastrointestinal disease |
Blood
(collected in blood culture bottles)
|
Gastrointestinal disease
|
| Stool
|
Gastrointestinal disease
|
Transportation:
Transport all specimens to the laboratory at room temperature
Specimen Processing:
All testing procedures must be performed within a certified Class II
biological safety cabinet (BSC). (Refer to the laboratory safety guidelines
above)
|
Specimen Type |
Preparation |
Inoculation |
Incubation |
|
White powder
(ensure that the blower of BSC is turned off while handling the
powder.)
|
Suspend a small amount in approximately 1ml of sterile distilled water.
- Cap tube.
-Vortex.
|
Streak out one drop of suspension on each of:
-Sheep blood agar (SBA)
-Chocolate agar (CHOC)
-MacConkey agar (MAC)
Innoculate1 ml of suspension in 10ml Enrichment Broth*
|
O2
35oC- 37oC x 18-24 hrs
|
|
Blood culture bottles |
|
Sub positives on SBA, CHOC & MAC.
-Gram stain.
|
As above |
|
Sputum |
|
SBA, CHOC , MAC
-Gram stain
|
As above |
|
CSF |
Centrifuge (1500xg for 15min)
Remove supernatant. Gram and culture deposit
|
-SBA, CHOC
- Gram stain
|
As above |
|
Swab, vesicular fluid |
|
-SBA, CHOC ,MAC
-Gram stain
|
As above |
|
Stool |
|
SBA, MAC, Phenyl Ethyl Alcoho l(PEA) or Colistin Nalidixic Acid (CNA |
As above |
* Subculture enrichment broth to SBA, CHOC, MAC. Incubate at 35oC-37oC
for 18 – 24 hrs.
Some reference laboratories are not using enrichment broth, however we
recommend using an enrichment culture until we seek further clarification
Examination of plates:
Examine plates at 18-24 hours.
Colony characteristics of B. anthracis : On SBA at 18- 24 hours,
colonies are:
 | 2-5mm in diameter |
 | Flat or slightly convex |
 | Irregularly round with a wavy border |
 | Have a ground glass appearance |
 | Often have comma shaped projections from the colony edge producing the
"Medusa head" colony |
 | Colonies have a tenacious consistency i.e. when teased with a loop the
growth will stand up like beaten egg white |
 | Colonies are non –hemolytic |
 | Colonies grow rapidly – individual colonies may be detected within 12-15
hours. |
Further tests:
Gram stain:
 | B. anthracis is a large gram positive rod (1-1.5 x 3-5 um) that forms
oval, central to subterminal spores (1 x 1.5 um) on SBA that do not cause
significant swelling of the cell. |
 | Spores are not present in clinical samples unless exposed to atmospheric
levels of CO2 |
 | Vegetative cells seen on Gram stain of blood and impression smears are in
short chains of 2-4 cells that are encapsulated |
 | Gram stain from growth on SBA occur as long chains of bacilli and are not
encapsulated |
Motility: B. anthracis is nonmotile. However a few non-pathogenic Bacillus
spp are non-motile
Presumptive Identification key for B anthracis :
 | Typical colony as described above |
 | From clinical samples - encapsulated gram positive rods |
 | Gram positive broad rod, spore positive = Bacillus spp |
 | Spores are non-swelling and oval shaped ( B. anthracis, B. cereus, B.
thuringiensis, B. cereus var mycoides) |
 | Non-motile: B. anthracis and B.cereus var. mycoides |
 | Non-hemolytic = Presumptive B. anthracis |
Action:
If a presumptive B. anthracis is identified, forward isolates to CAREC
Other tests include capsule detection, DFA , gamma phage.
Serological and rapid field tests are not presently available.
References:
Basic Laboratory Protocols for the presumptive identification of Bacillus
anthracis, Centers for Disease control and Prevention, Atlanta USA.
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