Healthcare Hygiene magazine November 2019 | Page 9

infection prevention
By Wava Truscott, PhD, MBA
When Prime Directives Collide:
The Survival Wars
T
he Prime Directive driving all humans is an internal
instinct to survive. Throughout the ages, man has
struggled and adapted to protect himself, his family, and his
tribe. This core drive to survive has advanced weapons for
protection, from crushing threats with rocks, to throwing
spears, and on to more powerful weapons. To survive
weather extremes, man huddled in caves, constructed
lean-tos, and moved up to more permanent structures of
wood, stone and cement.
The same Prime Directive drives microorganisms to adapt
or die. However, instead of innovative adaptations requiring
thought, bacteria experience genetic mutations that may or
may not be helpful. Mutations that protect bacteria enable
survival, while mutations that are not sufficiently protective
die off with the bacteria.
The adaptive capacity of bacteria has been incredibly
successful. Most successful mutations are passed on verti-
cally from generation to generation in a long looped single
chromosome composed of double-stranded DNA residing in
the nucleolus of the bacteria. The instructional information is
passed primarily during cell division, enabling future progeny
to survive in their environment. These traits include such
capabilities as biofilm formation for tribe protection, the ability
of a small number of bacteria to form one-occupant spores,
and the inherited capability that a few bacteria possess to
produce small colony variant (SCV) progeny that, in effect,
are invisible to the human immune system.
Some protective mutations can be transferred horizontally
to other bacteria unrelated to the original “mutant.” The
genetic instructions are encoded in a much smaller dou-
ble-stranded DNA loop, the plasmid. Plasmids can replicate
independently producing as many as needed to “share” with
other bacteria. Once a bacterium receives a plasmid, it in
turn produces replicates to fortify its own protection and
potentially to distribute to others. Plasmids are also vertically
passed on to progeny during cell division, thus improving
the odds of survival for their descendants.
Antibiotic resistance genes are very successful muta-
tions located on plasmids. The mutations only work on
specific antibiotic types and only by specific action modes.
There are at least 10 different protection modes that have
been successful:
Within the bacterial cell itself:
1. Blocks entry of specific antibiotic types trying to enter
bacterial cell
2. Flushes the antibiotic out of the bacterial cell before
it reaches their targets
3. Produces enzymes that break apart antibiotics before
they reach their targets
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4. Produce antibiotic-modifying enzymes that render
the antibiotic ineffective
5. Modify the targets so they cannot be impacted by
the antibiotic
6. Make so many clones of the antibiotic targets, that
the antibiotic is spent before destroying all the targets
Within the group-protective biofilm:
7. Exo-enzymes distributed throughout the biofilm
matrix. like land mines in the battlefield, digest specific
antibiotic types when contact is made
8. Many bacteria in the center of the biofilm, are altered
into persister cells that shut down (hibernate), not allowing
anything in – including antibiotics
9. Most biofilm-forming bacteria attract diverse bacte-
rial types to increase the odds of biofilm survival through
genetically diverse protective adaptations
10. Proximity and purpose of the (a) peripheral bacteria
in a biofilm “fortress” makes them the forward perimeter
guards. It is there that plasmids for diverse means of protec-
tion are most liberally shared. For example, the more means
of defeating antibiotics each defender possess, the more
effectively broad the antibiotic resistance. Bacteria deeper
in the matrix are responsible for (b) harvesting moisture and
nutrients, (c) metabolic waste disposal, (d) hibernating as per-
sister cells, and (e) transforming into “super surface-grippers.”
U.S. Daily Human Cost: Each day, approximately 5,000
Americans acquire a serious antibiotic–resistant infection.
Of those, about 63 patients will die and a large percentage
of survivors will suffer long term chronic consequences. By
2050, it is projected that untreatable antibiotic infections
with overtake cancer as the No. 1 cause of death globally.
U.S. Annual Financial Cost: Antibiotic-resistant infections
add $20 billion in excess direct healthcare costs and up to
$35 billion in additional costs to society for lost productivity.
As with any battle, attacking before the enemy can
establish a foothold and fortify a reservoir of resistant
pathogens is by far the easiest, most effective and least
costly means of patient protection.
It takes a team to do what’s needed, including infection
preventionists, OR and device reprocessing staff, environ-
mental services, engineering, and clinicians.
Infection preventionists must have help to handle required
reports, statistics and trending paperwork so they can be
actively on the floors, teaching, advising, admonishing,
finding solutions and supporting staff trying to do the right
things under pressure.
Wava Truscott, PhD, MBA, is principal of Truscott MedSci
Associates, LLC.
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