Re: NANFA-- Antibiotics

geoff kimber (
Wed, 13 Nov 2002 20:46:23 -0500

this is a pretty hot topic. As Jay alluded to a couple of days ago, I am a
pharmacist, and when I worked ICUs, I learned quite a bit about bacterial
resistance. Its a pretty detailed topic as you might imagine.

I'm coming late to this topic, so I hope I don't stir anyone up, but I do
want to make a couple of comments.

exposure to antibiotics leads to resistance. in fact, bacteria do some
really interesting things, like transfer DNA bits (plasmids) even between
species to share info on bacterial resistance. Plasmids have the nasty
feature of coding for resistance to many different (not necessarily related)
antibiotics. So if you expose bacteria to 1 antibiotic, they may end up
resistant to 10 different antibiotics and antiseptics. I am not a
specialist in aquaculture, so I cannot speak to the frequency of antibiotic
resistence in ornamental fish, however, I doubt the topic is widely
researched. Absence of evidence is not evidence of absence.

However, I am a bit more worried about other sources of antibiotics in the
environment - mainly the use of medicated animal feed. It has long been
known that adding antibiotics to ruminant feed increases growth rate. This
means more profit faster. Nationwide, the quantities used are huge, and
directly exposed to a major part of the food supply. There is extreme
concern that antibiotic laced animal feed will allow human pathogens to
become resistant to available antibiotics.

Another concern is triclosan. this stuff is everywhere. in deodorant,
toothpaste, hand soap, deodorant soap, bandaids, kitchen utensils - any
place you want to stop bacteria- it's there. Here's a brief excerpt from an
article I found on-line: (P aeruginosa is a serious human gram negative
pathogen that is found in all water sources)

begin quote:

Exposure of a susceptible P. aeruginosa strain to triclosan selected
multidrug resistant bacteria at high frequencies. These bacteria
hyperexpressed a multidrug efflux system due to mutations in a regulatory
gene. Resistance levels for several drugs were increased up to 500-fold in
these mutants, including resistance against the clinically useful antibiotic
ciprofloxacin, which was increased 93-fold. The mutations causing expression
of this efflux system were similar to ones previously selected by exposure
to antibiotics

end quote

bacterial resistance is a major problem in human medicine now. There are
bacteria out there that are not susceptible to any available antibiotics.
be afraid. be very afraid. However, while resistance can be caused by
aquarium use of antibiotics, I doubt that this is a significant source of
resistence in human medicine.

re: swimmers granuloma-
Strictly speaking, Mycobacterium marinum is not a form of TB. TB is a
specific disease caused by Mycobacterium tuberculosis. While M marinum is in
the same genus, it behaves very differently. Mycobacteria are naturally
difficult to kill. The genus includes the bacteria that cause tuberculosis
and leprosy - both diseases require months to years of therapy to control.
Interestingly enough, M marinum does not seem to acquire resistence easily.
As far as the $6 pill, there are cheaper alternatives that are just as
effective, but their manufacturers don't bring nifty mugs and pens to the

another point-

When I was a youngster in pharmacy school lo these many years ago, I was
told something humbling by one of my professors. He started off asking the
class what advances had resulted in the greatest increases in human
longevity. After we all proposed various therapies, he gave us the answer:
sanitary sewers.

People used to drop like flies from water bourne pathogens like cholera and
typhoid. The leading cause of death of children in third world countries is
diarrhea and dehydration. Sewers fixed all that. not antibiotics.

The vast majority of first world humans do not ever require the use of
life-saving antibiotics. However, those that *do* need them benefit

I see a parallel in fish keeping.

Good management practices will improve the health of the fish in our care
and will likely reduce the need for antibiotics to nearly nothing. However,
there will be specific individuals who do need antibiotics to continue

to be honest, I do not use antibiotics very much at all. The most common
time for me to use antibiotics is right after capture. After that, I rarely
use them except when my prize specimens get sick.

Geoff Kimber
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