public health preparedness and response
APHL Updates Resources and Outreach
for Sentinel Clinical Laboratories
By Samuel Abrams, MPH, specialist, Public Health Preparedness and Response
Biological threat (BT) coordinators are
tasked with ensuring that thousands of
clinical laboratories across the country
are adequately prepared to properly
rule-out and refer threats. The benefits
of training are obvious for the safety of
both the patient and the lab scientist, but
outreach can be an arduous task.
To address this need, APHL coordinated
the update and release of guidance
resources to help public health
laboratories connect with sentinel clinical
laboratories. Representatives from state
and local public health laboratories, the
American Society for Microbiology (ASM)
and the US Centers for Disease Control
and Prevention (CDC) participated in the
development of the materials.
Earlier this year, updates were made
to the Biothreat Agent Bench Cards, a
bench-side flipchart that provides a quick
reference point for some select agents.
The inclusion of identification methods
for B. cereus biovar anthracis and a Gram-
negative bacilli/coccobacilli rule-out
flowchart were two valuable additions.
Other updates included alignment with
ASM sentinel level clinical laboratory
protocols. Furthermore, the bench cards
provide new information for biosafety,
including details on performing biological
risk assessments. An accompanying
wall-mounted poster (see below) was also
updated, outlining the select agents’
characterization details. Both of these
resources were sent out via email to all
APHL members, BT Coordinators and
Biosafety officers in June, 2018.
Another major update has been to the
sentinel clinical laboratory definition.
The changes provide flexibility for state
public health laboratories to work with
their own non-microbiological sentinel
laboratories for outreach and training. The
definition addresses moderate complexity
testing by including statements on point-
of-care testing and culture-independent
diagnostic tests, providing guidance for
a range of testing sites that previously
have not been included on guidance-
related issues. The update also includes
statements on biosafety and lays out
the responsibilities of core laboratories
to communicate important biothreat
information with satellite laboratories,
ensuring that critical information is
clearly outlined and transmitted in a
timely manner.
APHL also supports training needs
assessments and preparedness training
programs for public health and clinical
laboratories. n
BIOTHREAT AGENTS
ANTHRAX
Bacillus anthrac is
• Large Gram positive rods
(1-1.5 µm x 3-5 µm)
• Smears of clinical specimens:
• Short chains (2-4 cells)
• Capsule present, no spores
• Smears from BAP and CHOC
culture:
• Long chains, no capsule
• Spores in older cultures;
oval, central to subterminal,
no swelling of cell wall
• Grows well on BAP and CHOC
• No growth on MAC and EMB
• Ground-glass colonies, 2-5 mm
on BAP and CHOC at 24h
• Aerobic growth as early as 4-8h
• Flat or slightly convex with
irregular edges that may have
comma-like projections
BRUCELLOSIS
GLANDERS
Brucella spp.
• Tiny, faintly staining, non-
clustered, Gram negative
coccobacilli (0.4 µm-0.8 µm)
• Pinpoint colonies at 24h, and
0.5-1.0 mm after 48h
• Non-hemolytic
MELIOIDOSIS
Burkholderia mallei Burkholderia pseudomallei
• Small straight, or slightly
curved with rounded ends,
Gram negative coccobacilli
(1.5 µm-3 µm x 0.5-1.0 µm) • Straight, or slightly curved Gram
negative rod
(2.0-5.0 µm x 0.4-0.8 µm)
• Cells arranged in pairs, parallel
bundles, or Chinese letter form
• Colonies may demonstrate
bipolar morphology in direct
specimens and peripheral
staining in older cultures, which
can mimic endospores
• Non-mucoid • Aerobic • Aerobic growth on BAP and CHOC
(CO 2 may be required by some
strains) • Non-hemolytic • No growth or pinpoint on MAC
at 48h • No growth on MAC or EMB • Catalase positive • Catalase, oxidase, urea: positive
(Oxidase may be variable) • Oxidase variable • X and V factor (satellite test)
negative (not required) • Non-motile • Distinctive musty earthy odor,
which is diagnostic (the odor is
apparent without sniffi ng)
• No growth at 42°C • Oxidase positive
• Polymyxin B and colistin no zone • Spot indole negative
• Penicillin resistant • Motile
• Amoxicillin-clavulanate
susceptible • Growth at 42°C
• Non-motile (although motility
testing not recommended for
suspect Brucella spp.)
• Non-hemolytic on BAP
• Spot indole negative
• Aerobic
• Non-hemolytic
• Growth on MAC (may uptake pink
dye)
• Polymyxin B and colistin no zone
• Penicillin resistant
• Tenacious, sticky colonies,
adheres to agar surface
• Amoxicillin-clavulanate
susceptible
• Catalase positive
TULAREMIA
PLAGUE
Francisella tularensis
Yersinia pestis
• Tiny, Gram negative coccobacilli
(0.2-0.5 µm x 0.7-1.0 µm)
• Plump, Gram negative rods
(0.5 x 1-2 µm) seen mostly as
single cells or pairs, and may
demonstrate short chains in
liquid media
• Poor counterstaining with
safranin (basic fuchsin counter-
stain may increase resolution)
• May exhibit bipolar, “safety-pin”
appearance in Giemsa stain or
Wright’s stain
• Pleomorphic
• Mostly single cells
• Aerobic, fastidious
• Facultative anaerobe
• No growth on MAC/EMB
• Scant or no growth on BAP; may
grow on primary culture, not well
on subculture
• Slow growing at 35˚C, better
growth at 25-28˚C
• Slow growing on CHOC, TM or
BCYE: 1-2 mm after 48h • Grey-white, translucent pinpoint
colonies at 24h, usually too
small to be seen, little to no
hemolysis on BAP
• Colonies are opaque, grey-white,
butyrous, smooth and shiny • At 48h, lactose non-fermenter
on MAC or EMB
• Oxidase negative • Catalase positive
• Catalase negative or weakly
positive • Oxidase, urease (at 35˚C) and
indole negative
• Satellite negative
• Beta-lactamase positive
• Non-motile
FOLLOW ALL LABORATORY AND BIOSAFETY PROCEDURES TO RECOGNIZE AGENTS OF BIOTERRORISM
YOU ARE THE FIRST LINE OF DEFENSE — REFER TO CURRENT ASM SENTINEL LAB PROTOCOLS
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Summer 2018 LAB MATTERS
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