Antibiotic-resistant bugs

Factual Questions
1

Currently the British Press is going ga-ga over a couple of deaths that have resulted from antibiotic-resistant germs running loose in British hospitals. There are simular reports from elsewhere from time to time.

It seems that fifty years of overuse of antibiotics has helped drum up a crop of nasties that are immune. It was to be expected I suppose.

OK, so if we presume that such a bug were to gain world-wide range, what would be the effects? After all no germ is immune to good sanitation, IR light or other precautions. It is not a return to the Middle Ages as we know about germs and other ways to fight them. So a minor problem then?

Of am I wrong?

How long will it take to come up with a new generation of kick-butt drugs?

2

MRSA (Methicillen Resistant Staphlococcus Aureus) is still susceptible to Vancomycin- so we CAN treat it, Vancomycin is just much less safe (and much more expensive) than the good old-fashioned penicillen derivatives. There is Vancomycin Resistant Enterococcus (VRE), which is harder to treat, and VRSA (Vancomycin Resistant Staph Aureus) has been reported, but it’s still rare.

Unfortunatley, when one type of bacteria (eg Staph Aureus or Enterococcus) is resistant, it is possible for many other types of bacteria to become resistant. we will NEVER be able to completely eliminate bacteria, nor would we want to. Even surgeon’s hands, after 5 minutes scrubbing with disnfectants and alcohol will still have some bacteria on them (it’s why they wear gloves). good hygiene and sanitation can only ever decrease the amount of infections, not eliminate them.

When the bugs cause infection, they’re hard to treat. No matter how much we’d like to treat a middle ear infection, a brain abcess or a joint infection with sunlight and disinfectant, it’s not practicable, simply because of where the infection is located. That’s why we like antibitoic tablets and intravenous solutions, because they can reach these inaccessible parts of the body.

BTW there are people working on new antibiotics, but they’re not just looking for something that will kill the bacteria.
It also has to have a tolerable side effect profile, as it’s no good killing MRSA if it kills the patient in the process.
The drug must have good bone and brain penetrance to allow it to get to infections within the bones, joints and CNS.
It has to be economically acceptable, for example, if a single dose costs $10 000, and a patient needs a dose every hour for 3 weeks, it’s not going to work out well as the next wonder drug.
It also has to kill bacteria by a method which they are not already resistant to…and are unlikely to develop resistance to quickly.

In other words, it might take a while.

3

Several years ago I read an interesting article on this. It seems that many bacteria can swap genes, including those for drug resistance. They also use antibiotic-like chemicals to kill off each other.
Anyway, the writer went on to say that the use of antibiotics is effectively a form of chemical warfare and that the germs have about a 3 * billion* year head-start on R&D.

Regards

Testy

4

They definitely do this, which is why hospitals try to isolate patients with MRSA or VRE, so that the bacteria don’t have a chance to mingle and swap genes. I remember in a lecture a few years ago one of my professors was talking about the danger if those two bugs (MRSA and VRE) ever transfered resistances, because vancomycin is pretty much top-of-the-line as far as antibiotics go, and if we lose that as a treatment for MRSA, we’d more or less be out of options. And now it’s already happening, as irishgirl mentioned.

You’re asking about worldwide range… well, antibiotic-resistant strains of TB are spreading already, and while it’s not quite like the black plague, it does kill people. The disease is already hard to treat, with a very long course of an antibiotic cocktail. Resistant strains are a nightmare.

As for research and development of new antibiotics, it’s picked back up again recently because of the threat of resistant strains, but for a while it slacked off as drug companies moved onto more “profitable” drugs. When you have strep throat, you tale an antibiotic for a week or two and you’re cured. When you have high cholesterol, you’re on pills for a very long time. And even though there are people working on them now, it costs a drug company hundreds of millions of dollars and takes 10-15 years to develop a new drug and get it on the market. And although they may start with a few hundred promising compounds, in the end maybe one or two will be effective, safe, and economically reasonable enough to make it onto the shelves.

Here’s an FDA article I found about antibiotic resistance. It’s old, but if resistance was a problem 10 years ago, it’s not going to be much better today. the FDA site has a whole section on antibiotic resistance here.

5

The MRSA and VRSA that irishgirl mentions are more “teachers” than killers.
The “parent” bug, Stapholcoccus Aureus, isn’t terribly virilent, but since it isn’t easily killed it tends to ride around in the noses and under the fingernails of hospital personel. The reason it spreads in hospitals is usually poor transfer control, as in, proper handwashing, barrier protection, and monitoring. If the infection control protocols are strictly followed, there would be no carriers. You can’t spread an infection that no one has. Unfortunately, it only takes one lapse to start the avalance.
The patients who are seriously affected are those with little or no reserve left to fight it off.

A few years ago, CDC secretly monitored some isolation rooms that had been problematic. Over 70% of those entering the rooms either skipped infection control procedures, or did them improperly. The most unreliable were doctors, especially surgeons.
They then monitored the same rooms, openly, and the rate of compliance improved only about 20% to about 50% compliance.
Doctors openly ignored protocols, often claiming to be “too busy” to follow, or even read the procedures. (sorry, I don’t have a cite, it was in a training film)

Many hospitals here, now do routine surveillance cultures on all staff noses. If MRSA is found, that person must treat for it, basicly, for the rest of their professional life. But its just a little ointment a couple times a day.

The truly scarey resistant organisms are the new strains of TB, and STDs that have been on the increase for the past few years.

The lessons to take away with you are:

  1. Don’t ask for antibiotics without confirmation (by culture) of an infection.

  2. If they are prescribed for a legitimate infection, take ALL of them.*

  3. If you are a health care provider (or even if you aren’t, :smack: ) keep your fingers out of your nose.

  4. Wash your hands well and often, including under each nail.

  5. Wear gloves for direct contact.

  6. Follow protocols for surveillance to the letter.

  7. To paraphrase Jim Morrison, none of us will get out of this alive, but do your best to put it off as long as possible, and don’t take anyone along on your ride.

  8. If you use good technique* all the time*, you don’t have to worry what the next patient might give you.

*Think of the infection as guerrilla warfare. The group of infiltrators are not all equal, some are stronger some are smarter. The smart/strong ones will live longest. If the firestorm is stopped before every one is dispatched the ones left will, by virtue of their strength/smart come back more efficient , stronger and faster.

Ok, I’ll get down now. Heck, I didn’t even know I HAD a soap box!

6

No. Think about the most sterile place you can. Hospital? Nosocomial (hospital acquired) infections are amoung the worst and most rampant in medicine. Lysol-addicts house? I guarantee they still get infections. As picunurse said, compliance with infection control protocols is very low. We’d never be able to eliminate infections based on that alone.

Another factor to consider is host range. Can the bacteria survive outside of a human, whether in the dirt or in an insect or animal? If there is another environment for the bacteria, it will act as a continuous reservoir of human infection. We were able to eliminate smallpox and nearly eradicate polio because they are both limited strictly to humans for survival.

7

You mean UV light. IR can kill them too, but only by cooking them. :wink:

8

And, for what it’s worth, this doesn’t mean the UV light in sunlight. That’s way too weak to kill bacteria. Generally, it takes a UV source within a foot or so of the bacteria to get any significant killing. So overhead UV lights don’t really help. Doesn’t stop companies from trying to market them, however…

9

You mean those 12 inch long Shielded UV lights mounted over the doors in the isolation rooms don’t kill the TB :eek: The first time I was shown those silly things I commented that they couldn’t be very useful. The person giving me the tour, was absolutely convinced .
In dialysis our RO water passed through a UV “tunnel” to reduce any bacteria load, but even that wasn’t expected to be 100% effective.

10

Every time I’ve seen these experiments done it’s required the light to be within inches of the surface to be decontaminated. If you get a totally honest rep, they’ll tell you that.

The UV tunnel is actually pretty effective. Usually, they are fairly narrow, maybe a foot or so in diameter, with UV lights on multiple sides. It does result in a significant decrease, but a few critters inevitably get through. It can be used for air systems too.

The real surprise with UV decontamination is how frequently the bulbs have to be changed. After something like 1000 hours, the emitted light is dramatically less effective. At that point, there’s ne visible difference in the emitted light, so it’s easy to forget. In my experience with lab hoods, very few people change the bulbs and then it’s only because they totally burned out.

I’ve come to view UV decontamination devices as a placebo effect. I always use a chemical disinfectant.