Any bio experts out there? ( bacterium)

[TillEulenspiegel]

Quick question .
Is there an identifiable constituent ( such as protein coat ) that MERSA and VRE are identifiable by yet?
Thnx.

[Badly Shaved Monkey]

I am not a bacterium but I play one on TV.

MRSA= Methicillin-resistant Staph Aureus

VRE= Vancomycin-resistant Enterococcus

They are different genera.

Did you mean to ask about MRSA vs VRSA (its even scarier brother), or did you mean to ask about MRSA and VRE vs the less dangerous members of their own species?

[TillEulenspiegel]

No I meant to ask about those specific organisms and Jesus don't even mention VRSA. (Ashes ,ashes ,all fall down!)

[Prester John]

They are defined by their interaction(resistance) to a particular antibiotic, methicillin or vancomycin. Obviously there is a genetic element that is coded, but they are for most practicle intents and purpose identical (except wrt antibiotic resistance) to normal members of their species. S.aureus is part of the human bodies normal flora. Enterococci are normal gut flora.

[TillEulenspiegel]

So theres no specific say receptor site on the coat that would differentiate them from their less dangerous brethren? All the differences reside in the DNA only? ( I'm Way out of my field here).

[Prester John]

http://www.cdc.gov/ncidod/hip/Lab/FactSheet/mrsa.htm

Staphylococcal resistance to oxacillin/methicillin occurs when an isolate carries an altered penicillin-binding protein, PBP2a, which is encoded by the mecA gene. The alteration of the penicillin-binding protein does not allow the drug to bind well to the bacterial cell, causing resistance to -lactam antimicrobial agents.

The easiest way to detect MRSA is by antibiotic sensitivity testing!

[Badly Shaved Monkey]

Originally posted by Prester John

The easiest way to detect MRSA is by antibiotic sensitivity testing!

Take 10 elderly orthopaedic patients. Sit them in an NHS hospital ward and culture their wounds after a week or so. What you grow will be MRSA. Easy.

[Rolfe]

Funny thing is - remember Jareth, the collie whose face fell off while CD was "treating" him homoeopathically? Well, when he was finally taken into the RVC, one of the first things the dermatologists suggested for why the poor dog wasn't responding to "treatment" was that he might have MRSA.

Huh?

Anybody ever yet reported an MRSA isolate in a veterinary hospital? No.

Anybody at that time reported an isolate of MRSA from a human loose in the community? I don't think so, or at least damn few.

Any special reason why this dog, who had had very little antibiotic treatment over the years, and who was living in the community with no known contact to a human case or anything, should have MRSA? No. About as likely as him having cholera I should think.

Staph aureus is a human organism. The equivalent skin organisms in dogs are Staph epidermidis (commensal and occasional opportunist) and Staph intermedius (pathogen). If we isolate Staph aureus from a dog, we can be pretty sure it got it from a human. (Probably the surgeon....) MRSA is completely unknown in veterinary medicine, even now.

Never mind, as soon as a case which isn't responding to treatment comes in, the first thing a couple of senior veterinary dermatologists theorise is that he has MRSA. Even though he's a dog, has been nowhere near a human hospital, and hasn't had much antibiotic treatment. The non-response to "treatment" couldn't possibly be anything to do with the fact that the "treatment" consisted of magic sugar pills, could it?

Sheesh, sometimes you have to wonder about your colleagues.

Normal service will now be resumed in this thread.

Rolfe.

[Prester John]

Originally posted by Badly Shaved Monkey
Take 10 elderly orthopaedic patients. Sit them in an NHS hospital ward and culture their wounds after a week or so. What you grow will be MRSA. Easy.

That is unfortunatly very close to the truth :(

[TillEulenspiegel]

Rolfe , now this is just plain scary:

"Between July and December 2000, four MRSA infections were detected in one veterinary diagnostic laboratory in southern Ontario. Case 1 was a dog with a post-operative MRSA wound infection. The isolate was identical to an MRSA identified a year earlier from her owner who had been hospitalized for surgery. Case 2 involved a dog with MRSA ear infection and concurrent inpatient orthopedic surgery, whose owners had frequent outpatient institutional contact. Case 3 was a horse with a post-operative MRSA wound infection whose owner was colonized with an identical strain. Case 4 involved a dog requiring leg amputation following an MRSA wound infection at a fracture site. The owner of the dog had previously been hospitalized for cancer. All the MRSA isolated from these animals were indistinguishable from the major human clones found in Ontario."
Article : http://www.cacmid.ca/abstracts_01/r2.htm

I'm a little acquainted to MRSA as I contracted it during a hospital stay. Treatment was 6 weeks of Vancomycin 2-weeks in hospital, 4 weeks outpatient course was (IIRC) 2G dilute in 500mL IV push via PIC line at 250mL Hr. Had peak and trough every ~4th day. I was eliminating the stuff at a ridicules rate. No red-man or kidney problems.

Reason I'm asking about methodology of detection , other then the convention of culturing, is because there are new class of SOS (sensors on silicon) that can directly measure not just gasses but VOCs and even proteins. Silicon protein detectors are "lattices" of electroststically bonded agents that react to a specific proteins make up. This is done in real time. If the PBP2a protein is accessible either directly or by a chemical or enzymatic breakdown of the bacterium , the possibility then would exist for faster detection and treatment.

Just an intellectual exercise for now.

[Benguin]

Originally posted by Prester John
That is unfortunatly very close to the truth :(

Yes, be sure to mix up post-surgical patients with ones coming in to have unidentified abcesses drained on the same over-stretched ward.

[Rolfe]

Till Eulenspiegl, I can't say I'm surprised. It seems so likely, it was only a matter of time. To the best of my knowledge it hasn't happened in this country yet, God alone knows why. I run a diagnostic lab for animals, and although we occasionally find Staph aureus, we've never found an MRSA yet.

I wouldn't be surprised if it happened though.

I just don't think it will happen in a dog belonging to a couple of woos who think real medicine is evil poison and all you need to heal is some sort of distance healing based on colours of the spectrum. So maybe it's not all bad being a woo. Oh yes, I forgot, the dog eventually died of an infection with a perfectly ordinary collection of organisms that were sensitive to quite a wide range of antibiotics.

Rolfe.

[TillEulenspiegel]

There are established protocols for the handling and treatment of MRSA patients, yet for a month, I sat in a chair next to old,infirm and immune suppressed patients with no isolation in fact there was much mutual contact either directly ( chairs touching, hand me your paper when done will ya ?, etc.) and nurses who did use gloves but only when in direct contact with blood, body fluids or instruments. ( who wants a cup of coffee?, lunch time Mr. Jones heres your tray...).
My brother owns a company that certifies labs,operating rooms, pharmacies, clean rooms and trains professionals in sterile techniques ( another reason for my interest in the subject ). He told a frightening tale about such minor (?) issues as un-sanitary behavior of Pharmacy techs that have and do cause death and injury , just because they didn't wash their hands after a bathroom break. Almost makes you paranoid.

[Rolfe]

When I was hospitalised with pneumonia of unknown origin, they put me in a single isolation room, and barrier nursed me. Maybe the fact that my boss had just rung the hospital and told them I worked in a veterinary lab had something to do with it?

The facilities were really good, I was told this was because the hospital was only about 5 miles from Garwick Airport. On day three the nurses started coming in without face masks, and I enquired sweetly if word had got out that I'd finally managed to clean my teeth?

Anyway, it was impressive. But this was 16 years ago.

Rolfe.

[Soapy Sam]

The spread of Common Sense Resistant Paranoia can be slowed by placing one's head under the blankets and never reading someone else's paper. Or any paper.

Rolfe- is there anything about the bacterium that would make it diffficult for it to make the generic jump? Imean, does Staph.a. KNOW it's a "human " bacterium? Anything about us it needs? Or are we just the only ones using antibiotics too much?

Because cows , sheep and chickens come to mind...

[Rolfe]

Originally posted by Soapy Sam
Rolfe- is there anything about the bacterium that would make it diffficult for it to make the generic jump? Imean, does Staph.a. KNOW it's a "human " bacterium? Anything about us it needs? Or are we just the only ones using antibiotics too much?We are not the only ones getting too much antibiotic. Vets are just as culpable as doctors. But vets don't keep so many very sick patients in hospital in high-density populations, so less resistance builds up.

Staph aureus knows it's a human bug. If you isolate it from an animal, you ask the surgeon how often he washes his hands. I've got it up from instruments and operating tables in vets' surgeries, when they've done sterility checks. The equivalent organisms on dog skin are Staph epidermidis (commensal and occasional opportunist) and Staph intermedius (pathogen). They're all quite closely related organisms, but distinct. If my memory serves me correctly, it used to be "Staph aureus var. intermedius" or something like that.

Rolfe.

[Soapy Sam]

But vets don't keep so many very sick patients in hospital in high-density populations, so less resistance builds up.


MM. I'm thinking battery farms / fish farms??? (I know they don't handle the fish much..)

[TillEulenspiegel]

Originally posted by Rolfe
We are not the only ones getting too much antibiotic. Vets are just as culpable as doctors. But vets don't keep so many very sick patients in hospital in high-density populations, so less resistance builds up.

Rolfe.
Factory farming where animals are treated regularly inoculated and then consumed are evidently one of the major avenues of human ingestion of anti-biotics.

Theres a little company ( Vindicator) about 20 miles down the road from me that uses a vault with a chunk of cobalt under water open the door close the door , open the vault wait 20 secs and veee-ola!, no live contaminants. Course if you think Homeopathy brings out the nuts , say the word "Radiation" and wham you have a parade of everyone from anti-world trade groups to Lesbians from Saturn on your door step.

Edit to add: Cross species pathogen jumping is a very bad thing. HIV is theorized to have jumped by human consuption of monkey meat contamiined with Simian I-dV. Ebola also seems to have similar roots.

[Rolfe]

Originally posted by TillEulenspiegel
Factory farming where animals are treated regularly inoculated and then consumed are evidently one of the major avenues of human ingestion of anti-biotics.What do you mean by "inoculated"? Vaccinated? That's the usual implication, and that has nothing to do with the subject on the card.

As far as the use of antibiotic-medicated feeds as growth promoters goes, there are very strict regulations (at least here, your mileage may differ) regarding withdrawal times before slaughter and the meat is tested to make sure there are no residues. Humans do not ingest antibiotics by this route.

I think feeding antibiotics to cattle to improve growth rates is brain-dead, nevertheless the evidence is heavily against its actually having been much if any of a factor in the development of antibiotic resistance in organisms important in human pathology. More likely to increase resistance of the organisms bothering the cattle themselves. Except they usually use preparations that don't have major therapeutic uses.

The main cause of antibiotic resistance in organisms important in human pathology is the use of antibiotics in man. Although I still think the use of antibiotics on animals which share human homes needs to be looked at with care too.

Rolfe.

[TillEulenspiegel]

The words should have been "treated regularly ", man did I step in a pile of cow dung ( pun intended). Seems there's as many nut jobs out there in regard to " factory farming" and over utilization of antibiotics as in my radiation scenario.

My observation was from memory ( perhaps faulty) about a Nova show on PBS in regard to a spate of food borne pathogens that had recently caused deaths and illness in the US. E.Coli, Lysteria, C.Parvum...

The US has different standards then the EU or Japan in prophylactic use on antibiotics in feed and via injection. One on the consensus' of the "experts "was the over use and residual amounts of A-Bs in Human food. I had no idea this was a favorite PETA-Vegan topic - jeez! Like I proclaimed I am out on my area here.

[Rolfe]

Originally posted by TillEulenspiegel
My observation was from memory ( perhaps faulty) about a Nova show on PBS in regard to a spate of food borne pathogens that had recently caused deaths and illness in the US. E.Coli, Lysteria, C.Parvum...Well now, that isn't humans ingesting antibiotics. That's organisms presumably acquiring resistance due to overuse of antibiotics in the cattle, then being transmitted to man. Very poor practice could result in this.

If regulations are tight enough, and enforced, humans do not ingest antibiotics even if they are fed to the meat animals. Doesn't happen in this country. As I said, your mileage may vary.

I still think it's a brain-dead idea though.

Rolfe.

[Soapy Sam]

My curiosity is about the earlier subject- We have all read the scare stories about rising incidence of human MRSA in hospitals.
Is there an analogous increased incidence among factory farmed, antibiotic fed animals of MRSA (or of it's analogues) in open wounds? (I realise a barn is not a hospital and the animals therein should be generally healthy, but I looked at cattle in a barn on Saturday- at least one in ten had minor open wounds , from scratching presumably. The beasts were mostly in contact with one another.
(They had a yard outside but seemed reluctant to move.)

[TillEulenspiegel]

Wow Soap's got a point , surprised I didn't pick up on it sooner.
What you were saying about the animal infections is the pathogen may be harmless to the dog , but she could be a typhoid Mary for humans?

[Rolfe]

Two in one. Antibiotic resistance patterns vary, but there isn't anything really comparable to MRSA in veterinary medicine. Because we don't have the sort of hot-house environment created by human hospitals. It's not the concentration of people, it's the concentration of sick people.

The most annoying thing is Pseudomonas aeruginosa which tends to be resistant to most of the usual stuff, but it's more of a nuisance than lethal, and as it's usually superficial (in ears) then topical antiseptics can also be used. Just don't tell Steve Dean (http://vetlab.co.uk/voodoo/vettimes5.html).

No, so far as I know, neither Staph epidermidis or Staph intermedius is a particular problem in man. They're just closely related organisms that seem to have a preference for dogs. And they're not especially resistant usually. Remember, most humans are harbouring Staph aureus, just not MRSA.

Rolfe.

[Zombified]

Originally posted by Rolfe
Remember, most humans are harbouring Staph aureus, just not MRSA.
Non-expert's curiosity: did resistance to a particular antibiotic arise once and spread, or can s. aureus evolve resistance in many hospitals?

Are there cases of "nuisances" evolving into something more serious, or are most serious diseases either old or made the jump from other species?

[Rolfe]

Ask Prester John. He's the real expert.

Rolfe (rank amateur).

[TillEulenspiegel]

The most annoying thing is Pseudomonas aeruginosa which tends to be resistant to most of the usual stuff, but it's more of a nuisance than lethal, and as it's usually superficial (in ears) then topical antiseptics can also be used.

Jesus are you p-sycic or something?
My sister -and I am not BSing You- is flying to the Mayo on Tuesday of next week because of a Pseudomonas A infection (colonization ? ) that has caused Pulmonary damage. She is on Cipro now and the maintenance dose seems to have stabilized her condition. Her background is in physiology and nutrition but she now is a personal trainer and runs classes at the local Health club. Seems the steroids she was taking after a bout on Pneumonia was masking the symptoms. No known cause of infection she doesn't swim in ponds or lakes . She is a very healthy individual with no immune problems. ( sept she's a dumb ass and didn't let herself heal after the original infection ). I suspect that she acquired it at the health club thru under treated whirlpool water or something along those lines. I find it hard to be clinically detached as I adore the woman , but I am curious and I can PM You with the outcome if your interested.

I'm gratified to have learned so much in one day.

Back to My original question tho.Prester, Rolfe, others? Is there a way to access the PBP2a protein directly?

[Rolfe]

Originally posted by TillEulenspiegel
a Pseudomonas A infection (colonization ? ) that has caused Pulmonary damage. She is on Cipro now ....Ow! Lungs are not a great place to get that bug. Still, they'll have done sensitivity tests and ciprofloxacin is a good antibiotic, and in an otherwise healthy patient the immune system should be able to cope.

You're right, it's a water organism, and a jacuzzi or something like that might be a source. I do hope she's OK, let me (or all of us) know how she gets on.

Your basic question is outside my area of competence, but Prester John's the expert.

Rolfe.

PS. Silly story. I was in the witness box as expert witness for the prosecution on a cruelty case. Among other things the dog had a bad ear infection. I remarked that from the smell it was a fair guess it was Pseudomonas aeruginosa. The defence barrister, who was an arrogant little creep, jumped up and objected that I couldn't say that because I hadn't mentioned it on my statement. I said oh yes I had. (I knew I'd listed the three main organisms cultured, and that was one.) He ran around brandishing my statement demanding to know where it was. When it was pointed out to him he went all red. He'd been looking for a word begining with S....

[Eos of the Eons]

Originally posted by Rolfe

PS. Silly story. I was in the witness box as expert witness for the prosecution on a cruelty case. Among other things the dog had a bad ear infection. I remarked that from the smell it was a fair guess it was Pseudomonas aeruginosa. The defence barrister, who was an arrogant little creep, jumped up and objected that I couldn't say that because I hadn't mentioned it on my statement. I said oh yes I had. (I knew I'd listed the three main organisms cultured, and that was one.) He ran around brandishing my statement demanding to know where it was. When it was pointed out to him he went all red. He'd been looking for a word begining with S....

http://www.members.shaw.ca/eostory/biglaff2.gif

Thank you for that Rolfe! Funniest thing I've heard in weeks!