FEATURE
recommend doing them if we can’t treat
any infections that might come up.” agencies to “accelerate response to
antibiotic resistance,” including:
In 2014, the World Health Organization
called AR “a problem so serious that it
threatens the achievements of modern
medicine.” • Improving antibiotic stewardship in
healthcare settings, including cutting
antibiotic use by 50% in outpatient
settings and 20% in inpatient settings
by 2020
Indeed, Craig said reservoirs of AR are
now so great, it is no longer sufficient
to simply stop misusing and overusing
antibiotics: “Even if we have perfect
antibiotic prescribing and use, AR would
still be a problem, largely because of
the transmission of [existing] resistant
pathogens.” These pathogens may
colonize individuals who never become
symptomatic. Or they may persist in
animal hosts, in healthcare facilities or
in the broader environment (for example,
after being discharged in hospital waste).
• Preventing the spread of AR threats
• Eliminating the sub-therapeutic use of
medically important antibiotics in food
animals
• Expanding surveillance for AR bacteria
in people and animals
• Creating a regional public health
laboratory network
• Establishing an AR specimen repository
and genetic sequence database
to facilitate development of new
diagnostic tests and pathogen-specific
treatments.
Bacteria containing the AR gene NDM-1
have been found in water pools in
New Delhi streets and in High Arctic
soils in Norway’s Svalbard archipelago,
demonstrating just how widely dispersed
the organisms are.
So far, Craig said, one of CDC’s biggest
AR achievements, “if not the biggest
achievement,” is the founding of the
regional AR Lab Network.
And because AR genes are often found
on mobile genetic elements called
plasmids, they can be transferred from
one microorganism to another without
any antibiotic exposure. So, for example,
KPC—the most common AR gene found
in carbapenemase-producing organisms
(CPOs) in the US—may be transferred
from Klebsiella to Salmonella to CRPA.
All 56 AR Lab Network members
perform basic testing, such as antibiotic
susceptibility testing and detection of
carbapenemases (enzymes that hydrolyze
certain antibiotics) in Enterobacteriaceae
and Pseudomonas aeruginosa isolates.
In 2013, CDC released an AR threat
report listing 18 microbes, collectively
responsible for more than two million
illnesses and at least 23,000 deaths in the
US each year. However, the report was
written before the launch of the AR Lab
Network, when data were less complete.
Craig said an updated report due out later
this year will note that, “as we expected,
the burden of AR infections is more
than we estimated previously; for some
pathogens, significantly more.”
The AR Lab Network—
“A Game-changer”
Two years after the threat report came
out, the Obama Administration released
its National Action Plan for Combating
Antibiotic-Resistant Bacteria. The
so-called “CARB” plan directs federal
PublicHealthLabs
@APHL
In addition, the seven regional AR Lab
Network members perform molecular
testing to detect colonization of CPOs in
people potentially exposed by an index
case; fungal susceptibility testing of
Candida species; colonization screening
for Candida auris; and detection and
characterization of emerging threats,
such as mcr-1, a bacterial gene that
confers plasmid-mediated resistance to
colistin (the drug-of-last-resort prescribed
for Tamika Capone). AR Lab Network
laboratories also provide isolates for
the new CDC/FDA AR Isolate Bank and
for federal whole genome sequencing
projects.
The TDH Division of Laboratory Services—
the state public health laboratory—is
the Southeast Regional AR Lab Network
Laboratory that provides core AR Lab
Network testing for six states plus Puerto
Rico, expanded drug susceptibility testing
APHL.org
Urgent Threats
• Clostridium difficile
• Carbapenem-resistant Enterobacteriaceae
• Drug-resistant Neisseria gonorrhoeae
Serious Threats
•
•
•
•
•
•
•
•
•
•
•
•
Multidrug-resistant Acinetobacter
Drug-resistant Campylobacter
Fluconazole-resistant Candida
Extended spectrum ß-lactamase producing
Enterobacteriaceae
Vancomycin-resistant Enterococcus
Multidrug-resistant Pseudomonas
aeruginosa
Drug-resistant non-typhoidal Salmonella
Drug-resistant Salmonella Typhi
Drug-resistant Shigella
Methicillin-resistant Staphylococcus
aureus
Drug-resistant Streptococcus pneumoniae
Drug-resistant tuberculosis
Concerning Threats
• Vancomycin-resistant
Staphylococcus aureus
• Erythomycin-resistant Group A
Streptococcus
• Clindamycin-resistant Group B
Streptococcus
Source: CDC. Antibiotic Resistance Threats in the United
States, 2013
Summer 2019 LAB MATTERS
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