Environmental Chemistry Field Trip – Day 1, Part 3

There were two more stops on the first day of the field trip. After Appolinaris Spring, we stopped off at the “Sheepeater Cliffs”, named after the local natives’ use of mountain-goats for food. I did get a picture of the small cliff, but who cares. You’ve seen one columnar basalt formation, you’ve seen them all, right?

Oh, well, in case you haven’t seen even one yet, here’s one:

Columnar Basalt Formation: Sheepeater Cliffs, Yellowstone National Park

It’s actually kind of interesting – despite the fact that Yellowstone is essentially one gigantic crater left by a volcano explosion, lava doesn’t seem to be a common feature at all. The reason seems to be that the volcanic explosion was an explosion of steam, not melted rocks. Put simply, water seeps down into the ground and gets trapped on top of magma, which is naturally extremely hot. The water can’t boil away as steam, though, because it’s trapped under all that rock, which keeps the pressure high enough that it stays liquid even when it’s superheated. Then, one day (about 600,000 years ago, if I remember correctly) somewhere a crack opened up enough to start letting the water flow out. When it got out from under all the rocks, the reduction of pressure let the superhot water suddenly explode into a cloud of steam. As the water shot out as steam, it let off some of the pressure on the water still trapped underground, which could then also explode into steam….and the whole area got flung into the air on the exploding, superhot steam. Kind of like the way a perfectly innocent looking bottle of heavily carbonated beverage can suddenly erupt in a spray of bubbles if you open it too suddenly.

Or at least, that’s my I’m-not-a-Geologist understanding of the process. The point is, melted rocks aren’t really a big part of the park area’s surface, so it’s interesting to see the basalt cliffs here. The giant hexagonal columns are actually huge crystals of that formed as the melted rock solidified.

This was just a brief stop, though. We piled back into the field-trip vehicles and headed for the Mammoth area of the park. I was originally going to cram that stop into this post, too, but I’m still editing it down to make it less pedantic. Unless my Vast Horde of Loyal Readers would LIKE pedantic…

Incidentally, the College Blogging Scholarship submissions are done as of midnight tonight. Or midnight tomorrow morning, depending on whether you think of midnight as the end or beginning of a day. Finalists get announced on Monday. Here’s hoping I’ll be one of them. That also means that if anyone has any suggestions or comments about how I’m running the blog, the topics I’m picking, and so on, now would be a good time to speak up…

Meanwhile, a couple more posts on the field trip coming up (possibly another one later today) and then I’ll move on to other topics.

Environmental Chemistry Field Trip – Day 1, part 2

Our next stop was Appolinaris Spring, which seems to be an uncommon thing in Yellowstone National Park: ordinary springwater. No sulfuric acid, no steam, just plain old water that sinks into the ground and then comes back up later. For most of the park’s history, it seems like this used to be a popular place to stop to get a drink of water.

water emerging from small copper pipes
Although the signs around the spring now all suggest that you really shouldn’t drink it, at least not without filtering it first, I’m kind of kicking myself now for not having tasted it. Perhaps I’ll have to go back on my own time and try it.

Our on-site tests showed a pH of 5.9 (slightly acidic: milk is normally around 6.8 or so, Root Beer somewhere around a more acidic 4.0, cola beverages around 3.0, for reference…), relatively low TDS of about 100ppm, coming out of the ground cool (about 7°C, or 43°F), with very little dissolved Oxygen (about 6.0ppm) and faintly carbonated (300ppm CO2). It reportedly didn’t taste too good, but having foolishly missed out on tasting it, I don’t know why.

There were hints that perhaps contamination from surface water – like rain trickling through bison poo – but quite some time ago they sealed the spring up to protect it from that kind of thing. This is the actual spring now:

Appolinaris Spring is a concrete box in the ground with locked metal tops...
Even so, the signs still try to discourage people from drinking the water coming from the pipes that lead out of the spring, which I take to be the park service covering themselves just in case someone claims to get sick from it. (“Hey, we TOLD you not to drink it!”).

Appolinaris: This spring water has been used by visitors since early days of the park.  However modern water tests show periodic contamination.  Park waters, even though clear and running are subject to pollution by wildlife.  As with all untreated water, purify before drinking.
Periodic pollution by wildlife? What the…

The northern end of a south-bound bisonOh, right. Natural bottled-spring-water flavor. Hey, it’s natural, it’s got to be good for you, right?

And to end this post on a complete and totally baffling non-sequitur: the student lounge I’m sitting in right now has a television constantly tuned to some cheesy mass-media channel. Today it’s “E!®”. I overheard something on it just now that made me sit up and take notice: Evidently “Leprechaun” made a profit. Wow.

One never knows what kind of amazing things one might learn at college…

Environmental Chemistry Field Trip – Day 1, part 1

I can think of a number of things to complain about with regards to living where I do. However, it is nice that we live near enough to Yellowstone to day-trip there. In fact, it’s close enough for my local college to take field-trips there – which we did.

Environmental Chemistry spent the weekend there, examining the area, discussing the chemistry of the natural waters and geothermal features, and collecting samples (yes, we had a permit for this…).

We started with a stop by the side of the Madison River to collect a sample of the surface water. Clear, cool (12°C, or about 55°F), mildly basic (pH of about 8.0), and a TDS reading of about 300ppm, which is roughly the same as mildly to moderately hard tapwater, I suppose.

sampling water from the Madison river

The sampling device -seen being hurled over the water here – is kind of interesting – it’s a hollow tube (a bit of plastic pipe) with two spring-loaded balls that slam shut on either end to trap the water inside when you tug on the string. That lets you throw the device out and trigger it when it gets to the precise spot that you want to take a sample from.

We made a brief stop at Beryl Spring afterwards. We didn’t do any sampling here, but we did talk about acid-sulfate water systems. “Reduced” sulfur – as Hydrogen Sulfide gas – comes boiling out from underground along with steam, and ends up being oxidized by oxygen from the air to become sulfate in the end – combining with the water and forming sulfuric acid.

Sulfur-encrusted pipe at Beryl Spring

Of course, it doesn’t go from sulfide to sulfate all at once. There’s a stop along the way as elemental sulfur. The whitish-yellow stuff here is crystals of elemental sulfur. The black stuff you see is…also crystals of elemental sulfur. The difference is just how the atoms of sulfur collect together. The black form is actually a little less stable than the yellow, so it tends to form first, but then slowly convert to the yellow form over time as the sulfur atoms settle into a more stable arrangement. Being a chemistry class, we didn’t really discuss the possible microbial activity that might be involved here. Note the small patch of dark-green there. I suppose this could be a “Green Sulfur Bacteria“, which does something like photosynthesis except that it makes sulfur instead of oxygen in the process. These are normally anaerobic but perhaps the concentration of hydrogen sulfide (H2S) and carbon dioxide gas coming out of the ground right there is enough to crowd out the oxygen. Alternatively, it could just be a heat-loving cyanobacterium or something.

I really wish I wasn’t too poor to buy a good field microscope to go along with the good lab microscope that I am also too poor to buy…

The last two stops of the day – Appolinaris Spring and Narrow Gauge Spring – will be in the next post…

This weekend should be worth at least one decent post…

This weekend, one of the two of this semester’s classes that I have not yet used for a “what I learned in school today” post took a field trip.

Yes, Our “Environmental Chemistry” lab went to Yellowstone National Park and (legally – we had a permit and everything) did some water sampling. We got some on-site lectures about the types of water systems in the park, considerations involved in sampling things, and so on. All in all, I thought it was pretty interesting, but after spending the entire weekend either driving to or from the park or walking around in the park I’m a bit exhaustipated. Plus, bummed out that I can’t afford a good portable field microscope to go with the regular microscope which I also can’t afford. Woe unto me. I imagine the permit we had would have allowed me to also dangle some slides in the water to look at.

I did record a GPS track of both days field-trips, I got ICBM addresses for our sampling sites, and a number of photographs with my cheap and ancient digital camera along the way. Give me some time and I’ll get at least one real post out of it.

Meanwhile, a bit of trivia: “The Microsoft Network” search system is pretty Fupped Duck. I do get the occasional obviously relevant hit from one of their searches, but the great majority seems to be “hits” from random one-word searches, many of which seem to refer to words that appear nowhere on the site (and others of which are so broad I have no idea how many pages some MSN user would have to click through before hitting my site. For example, while I like to think I’m making a reasonable effort to do interesting science blogging, I’m having trouble imagining that this blog would show up in the first few pages for a search consisting solely of the word “science”…which one of the recent hits seemed to show.

Actually, this probably has less to do with users than with Microsoft itself – the hits for this don’t appear to be loading real views (it pulls one page and doesn’t reference, for example, images) though it is coming from “The Microsoft Network” addresses. Perhaps Microsoft has one of their bots masquerading as a real user (the user-agent string looks like regular “Internet Explorer 7″)…even the IP address resolves to a bogus name ” bl2sch1082217.phx.gbl.”, for example) which doesn’t resolve back the other way. Of course, it’s also possible the hit is ENTIRELY bogus and the “referer” tag that seems to indicate this is also faked. Perhaps it’s time to start blocking Microsoft…or maybe just messing with them. This apparent standards abuse and obfuscation of what exactly it is that they’re trying to do with my blog (and messing up my logs!) kind of bugs me. (Moral of the story is probably “Everybody should just use Google“…)

Sure “Cardboard Sarcophagus Instructions” is a pretty weird search, too, coming from Google, but at least I know why THAT one got here. I doubt the searcher – possibly from the Memphis, Tennessee area – was really searching for metaphors for expired JellO boxes.

Art historians – do they minor in Purple Prose?

Let us read from the Book of “Art Across Time”, chapter one, page 36:

“This particular painting seems to represent either a ritual or a supernatural event. In contrast to the animals, which are nearly always in profile, this creature turns and stares out of the rock. His pricked-up ears and alert expression suggest that he is aware of an alien presence.”

Wow, that must be one exceptionally detailed and well-preserved cave-painting, to convey all of that. Let’s have a look:

Okay…to me the “head” looks like an indistinct smear, with spots that a human mind – tuned to recognize patterns, especially faces, even if the patterns don’t actually exist – might interpret as some kind of face. To me, it looks kind of like a crudely-drawn cartoon-animal face, with overwhelmed-Charlie-Brown-style bugeyes, a button nose, and the tongue hanging out of one side of its mouth. Yet, somehow, I don’t feel inclined to suggest that this is what is actually there. Personally, I’d be more inclined to suspect that the artist (estimated to have lived 13000-15000 years ago) had trouble finishing the drawing and gave up. Yet if you poke around for information about this image, you find all kinds of breathless prose about it. So, where does all the poetic language about the possible “meaning” and interpretation of the Trois-Frères “Sorcerer” come from?

I suspect it all comes not from the seemingly rare photographs of the original cave-painting, but from the famous and heavily-embellished sketch made by Henri Breuil:

Yeah, that’s not what I see in the photograph of the original, either.

Apparently, this cave-painting is about 13 feet off of the floor. Monsieur Breuil described having to stand with one foot on a small projecting rock, then half-turn and sit up against the cave wall while trying to juggle his light and drawing implements to make hist sketch.  Sounds to me like the cave-painting is in a hard-to-reach spot, perhaps supporting my “artist had trouble drawing there” hypothesis? I also can’t tell from the original if all of the figure was painted at the same time, or if perhaps someone started out drawing a deer or something of the sort (the hind legs look about right for that proportionally, prior to the ‘human-lower-leg’ part), and hundreds of years later some wiseguy came along and drew human-type lower legs and feet on the end of the deer’s legs as a joke, for that matter.

The Art History class is interesting, but the amount of speculative-sounding interpretation of the art and architecture without supporting citations is something of a culture-shock to me after the last couple of years for more “hard-science” classes.

Anybody see anything there in that original painting that I’m missing? Or for that matter, know where to find a GOOD photograph of it?

What I Learned In School Today: Mortals have Limits, and Socrates was a jerk…

…Or at least, Plato’s accounts of him make him seem that way.

We’ve been reading (as English translations) accounts of Socrates’ trial and related occurrences as written by Plato. It started off with a possibly fictional dialog before Socrates’ trial, between Socrates and some guy named Euthyphro, who is some kind of priest.

In short, they get to talking about why they are there at the court, and it turns out Euthyphro is there to accuse his own father, who has apparently committed what we in the modern U.S. would call “manslaughter”. Euthyphro’s father had caught a murderer, then tied him up and thrown him in a ditch while he sent somebody to ask the authorities what to do with the murderer. While waiting for the messenger to return with the answer, the murderer in the ditch had evidently died. Euthyphro says “piety” demands that his father be tried for the death of the murderer but complains that everybody seems to think that hauling his own father to court for this is “impious”. And now you have the backstory for a long, involved, and ultimately unsettled discussion of just what the heck “piety” is supposed to be.

That’s where you notice that Socrates is a sarcastic butthead who thinks he’s on a mission from The Gods™ to prove that everybody is an ignorant fool. He puts on a snide show, pretending that he expects Euthyphro will reveal The Secret Of What Piety Really Is (Socrates claims that the knowledge will be useful for his own defense at his trial later) all the while busily demonstrating that Euthyphro really can’t answer the question.

The argument dances around various definitions. They more or less settle on the notion that “piety” is something that pleases all of the Gods (and impiety, by definition, displeases all of the gods), and that The Gods™ love an action because it is pious rather than something being pious because it is loved by The Gods™. (There’s a bit of virtually Dickensian pedantry there involving whether something is “being carried” because someone is carrying it or whether people carry things because they are “being carried” objects.) I guess that means nobody would have to worry that they’d wake up one morning and discover that The Gods had decided on a whim that “piety” would mean raping puppies and eating babies for the next few days. They manage to reach agreement that “piety” has something to do with being like a servant to the gods, but are completely unable to come up with a definitive test by which they could define any particular act as “pious” or “impious”.

Euthyphro finally says (more or less) that hey, he’d love to stay and go around and around and around and around with this annoying little brain-teaser but he’s got places to be and things to do, and the dialog ends with one last bit of Socratic Sarcasm as Socrates wails about how he was hoping to show up at his trial and tell everyone he’d learned the divine secret of Piety from Euthyphro and therefore wouldn’t be accidentally corrupting the youth with his lack of wisdom any more…

I have to wonder if Plato wrote this dialog so that readers would understand why so many Athenians wanted to get rid of him…

Of course, as an (self-proclaimed) Applied Empirical Naturalist, I think they’re whole problem is that the knowledge they were seeking was defined as something that would only necessarily exist in the minds of Supernatural entities – since “piety” and “impiety” are entirely defined in terms of what The Gods thought, it’s not clear that “piety” can be known outside of the Invisible Giant People Up On Mount Olympus. Of course for Euthyphro, being a professional priest, admitting that he doesn’t – and maybe can’t – know what “piety” actually is and that he really has no clue what’s going on in the minds of The Gods would be a definite Career-Limiting Move, and Socrates doesn’t seem (to me) to actually care what it means so long as he gets to prove that Euthyphro doesn’t know either, so it’s no wonder that this point doesn’t come up.

I wasn’t kidding about the “thinks he’s on a mission from The Gods™ to prove that everybody is an ignorant fool” comment, either. In his “Apologia” (defense speech during his trial), as reported by Plato, Socrates describes how someone once went to the Oracle at Delphi and asked if anyone was wiser than Socrates, and was told that, no, nobody was wiser than Socrates. Socrates says he interprets this to mean that nobody is really wise and that this answer from the Oracle (who is just passing on messages from the Gods, after all) means that he has a sacred duty to go around demonstrating this fact – which is the basis of the famous “Nobody knows anything, but I know I don’t know anything, so I know more than anybody else” flippant description of this argument.

Oh, and one unrelated odd fact – the introduction to the translation says that Socrates is about 70 years old during this trial, but at one point during Socrates’ rambling defense speech he explains that he wouldn’t want to be like other people who show up in court and have their kids plead with the jury for mercy in order to avoid punishment. Socrates says he had three kids – one adolescent and two who are “children”. So, wait, he’s wandering around Athens unmarried, when suddenly he runs into some woman willing to shack up with a penniless, irritating old guy who’s almost sixty and they have three kids who survive childhood? What?

This isn’t discussed at all, really, it just struck me as a really odd circumstance…

What I Learned In School: “Valid” arguments

The new semester has begun on this, my last schedules semester as a mere old Undergraduate. This semester’s primary purpose is to fill in the two vitally important “general education” goals for my current Institute of higher learning: Art Appreciation and Philosophy.

I added a “What I Learned in School Today” category to the blog just because of this semester. My loyal readers (all 2-4 of you…) can look forward to occasional posts on other aspects of my Higher Education as the semester goes along, besides microbiology. On the metaphorical menu over the next 16 weeks: “Introduction to Philosophy” (today’s topic), “History of Western Art“, Applied Calculus, and finally I have a chance to take Environmental Chemistry.

Prior to reading some Plato for next week, we started out “Philosophy 101” with a discussion of “Valid” arguments. In Philosophy, this has a very specific meaning. If you make an argument in the general form of “This, and that, therefore something”, the argument is “valid” when if “This” and “that” are both true, then “something” must also be true.

The thing that most of the class seemed to have trouble with is that being “valid” has nothing to do with whether or not the argument is “sound“, or whether the statements in the argument are true.

An example from the class:

All mammals have lungs.
Whales have lungs.
(Therefore) all whales are mammals.

This is an invalid argument, despite the fact that every statement is actually true. The reason is simply that the fact that whales are mammals does not automatically follow from the fact that they have lungs. (Chickens have lungs, too. Does this mean chickens are mammals?…)

It took two class sessions before most of the class seemed to “get” this. I felt as though I was in Junior High again…though I think this had more to do with watching the freshman girls in front of me passing notes during the class. Come on, kids, grow up! We adults are using IM for that now! Sheesh. Kids today…

On the other hand:

You’ve got to be some kind of genius to attend college and blog at the same time.
I attend college and I blog at the same time.
I am, therefore, a genius.

is a valid argument. As written, if both of the first two statements are true, then the third statement must be true. This is where the value of valid arguments come in – if it turns out that the conclusion is false, then one of the premises must also be false. If anyone were to discover that I am, in fact, not a genius, then either it’s unnecessary to be a genius to blog and go to college at the same time, or perhaps I’m paying someone else to write this stuff for me.

Who cares, I’m a science major, not a philosophy major, right? Except: a properly designed scientific hypothesis should be a premise in a “valid argument”, and an experiment is merely a test to see if the argument is unsound. For example:

All lactic acid bacteria, grown in otherwise sterile milk, will make yogurt.(the underlying hypothesis being tested)
I inoculate sterile milk with a culture of Pediococcus damnosus(the test performed by the experiment)
(Therefore) I obtain yogurt. (Expected results and conclusion of the experiment)

This is (as far as I can tell) a completely valid argument. Now, I haven’t actually done this experiment, but let’s pretend I did, and the end result was a smelly mass that kind of looked like yogurt except it turned out to be slimy rather than firm. I cannot in fairness call it “yogurt”, so my conclusion in the argument is false. Thanks to the magic of Valid Arguments™, I know that either my assumption is wrong (maybe not all lactic acid bacteria turn sterile milk into yogurt after all), or there was a problem with the experiment (perhaps the milk was contaminated with something and wasn’t really sterile, or I grabbed a culture of something other than P.damnosus by mistake.)

Assuming I carefully recheck the materials and repeat the experiment to confirm that I really am inoculating actually-sterile milk with a definitely clean culture of P.damnosus and continue to get the same results, then my hypothesis – the first premise in the argument – must be false. I have to then go back and revise my hypothesis and test again, until I have a hypothesis that seems to consistently generate true conclusions. Thus, the “valid argument” is the basic tool which allows hypotheses to grow up and become theories.

Incidentally, some Pediococcus damnosus strains are a cause of “ropy” wine, which is why I chose that example. I don’t actually know what, if anything, it would do to pure, sterilized milk, though.

Coming up next: I picked up a 100-year-old microbiology book while on vacation!

Poisoning Prokaryotes in the Park

(Well, okay, it was a “Pathogenic Microbiology Lab”, not a “Park”, but whatever).

Antibiotic Susceptibility of a Poor, Innocent Microbe

Objective:Experience the awesome power of the mighty Antibiotic Susceptibility Test, wielded against an unsuspecting bacterial organism!


Every day, billions of innocent bacteria are ruthlessly slaughtered by antibiotic substances introduced into their callous, inconsiderate hosts. Condemned to death as nuisances due to nothing more than the potential inconvenience of debilitation, tissue necrosis, death, halitosis, and other minor problems, the unstoppable might of all medical science is focussed on our prokaryotic friends like medical professionals around the world focussing the rays of the sun through a thousand magnifying glasses to obliterate innocent prokaryotic “ants”.

The ?-lactam antibiotics – the blahblahcillins (Penicillin, Ampicillin, etc.) and the Cefablahblah compounds (Cephalosporin, Cephalothin, Cefuroxime, etc.) all interfere with the formation of the bacterial cell wall – loosely analogous to the human epidermis. This treatment viciously targets the hardest-working, actively-reproducing bacteria, spilling their guts as they attempt binary fission, while leaving the lazy, dormant microbes alone. Gram-negative bacteria are somewhat protected from this torture by their outer membrane, but some (such as ampicillin) can affect even some of them. Gram-positives, with their simple structure, are hardest hit. A few microbes have learned to counter this by secreting an enzyme which disables many of these drugs, though medical science has countered with clavulanic acid – an inhibitor of the ?-lactamase enzymes. Enzymes resistant to inhibition by clavulanic acid are being developed as part of this continuing arms race.

Chloramphenicol is an artificially manufactured bacteria-poisoning chemical synthesized in laboratories (though it was originally obtained during interrogation of a captured Streptomyces species) which interferes with protein synthesis at the 50s ribosome. Erythromycin has the same affect, by a slightly different mechanism, and is a macrolide – a class of large molecules with lactone rings which resemble in shape the poisoned ninja throwing-stars seen in movies. Both of these chemicals are bacteriostatic rather than bacteriocidal, but are broad-spectrum. Chloramphenicol’s devious action sometimes backfires on a small number of people, causing potentially fatal aplastic anemia.

The Sulfonamides are also bacteriostatic, and are competetive inhibitors of enzymes that convert the nutrient PABA into biochemical products vital for prokaryotic health. Much like a hypoglycemic person with diarrhea given a “cupcake” made entirely out of Olestra® and Sucralose, the microbial victim of this chemical ingests it but finds that it merely inconveniences the metabolic processes rather than feeding them.

Tetracycline (the first of the Tetracycline-type antibiotics) and Tobramycin (an Aminoglycoside) both jam the gears of protein synthesis, inhibiting the action of the ribosome in the former case, and actively causing erroneous protein formation in the latter. The latter effect is outright bacteriocidal, causing the poor bacterium’s protein assembly systems to make broken enzymes until the cell’s protein factory is bankrupt and has to lay all the enzymes off. Tetracyclines appear to only slow down the cell, but in the cutthroat competition for cellular activity in the human body, this stumbling can be a death sentence for the business of prokaryotic replication.

In order to determine which of these lethal agents to deploy against the oppressed bacteria, a medical professional may capture a microbe and torturously test various agents on it, watching without emotion to see which ones destroy the microbe most efficiently. This awful, coldly clinical process is standardized in the Medical Microbiologist Field Manuals on Interrogation as the “Kirby-Bauer”[1] antibiotic susceptibility test. In these tests, 6mm diameter paper disks soaked with various antibiotics in specific amounts, is pressed onto a growing young microbe culture to see which ones are most destructive, leaving desolate areas devoid of life in the culture…

Recently, we got to do this..

Materials and Methods:

A colony of Pseudomonas aeruginosa was lured into a culture tube with the promise of free candy. Happily replicating, this culture was transported to a secret location containing Mueller-Hinton agar. 100?l of this culture was told that it had won an all-expense-paid stay at a four-star hotel with room-service, and was plated onto the agar. The culture was then strapped down and tortured for its secrets by application of 12 antibiotic-soaked disks. The torture was performed at 37°C for 24 hours, and the results measured with a ruler.


The defiant Pseudomonas organism bravely withstood the application of Ampicillin, Cephalothin, Chloramphenicol, “Triple Sulfa”, Nafcillin, Cefazolin, Amoxicillin with clavulanic acid, Cefuroxime, and Penicillin G. Erythromycin seemed to cause the subject some discomfort. It was not quite able to grow to the edge of the antibiotic disk all the way around but was able to get within less than a millimeter of it, even touching it in a few spots. Tetracycline was unbearable to the subject, who was limited to a 11mm (diameter) zone of inhibition around the Tetracycline-containing disk. Finally, Tobramycin (zone of inhibition approximately 23mm) finished breaking of the subject, who then confessed to several murders of immunocompromised individuals, robbing a “Wal-Mart”, and once molesting an archeaean of the genus Thermoplasma. Investigations may already be underway to determine the authenticity of these confessions. Then again, they may not.

Conclusions and Discussion:

Pseudomonas aeruginosa is a hardy little bugger who can put up with a wide variety of antibiotic insults. Its weak point appears to be its ribosomal machinery, as this was the target of the three drugs which had any apparent effect. Should intelligence indicate the threat of attack by the terrorist Pseudomonas organization, ribosome-targeting, protein-synthesis-inhibiting agents should be deployed as a countermeasure.


[1] – Bauer AW, Kirby WM, Sherris JC, Turck M, “Antibiotic susceptibility testing by a standardized single disk method” Am J Clin Pathol. 1966 Apr;45(4):493-6

[2] –Tortora GJ, Funke BR, and Case CL, “Microbiology – An Introduction (sixth edition)” 1997, Benjamin/Cummings Publishing Company, Menlo Park, CA