MRSA and Animals

August 2, 2010 6:11 PM

Optimal control of MRSA's spread and diversity would involve attention to the role of pets and livestock, especially factory-farmed livestock (40 minute podcast -- no transcript, but here is the text of an interview that covers some of the same ground as the podcast.) Science journalist Maryn McKenna: "[Bacteria are] unpredictable and dynamic . . . We have few treatment options, so we need to be much more thoughtful."

Worms & Germs Blog observes: "There's a line between prudence and paranoia, and we don't want to create a population of germophobes who won't leave the house. However, we want to increase awareness so people do a better job of things like washing their hands" and asking health care providers [and vets?] to wash their hands, "and covering their mouths properly when coughing or sneezing."

"We are not a population of people living with dogs, cats, horses etc. - we are a population of animals."

US-specific details, and suggestions for change, are in McKenna's blog and her new book, Superbug. The FDA is accepting input until August 30 on its Draft Guidance on the Judicious Use of Medically Important Antimicrobials In Food Producing Animals.

Previously.

Also, interesting non-MRSA tidbits from the Worms & Germs Blog:
If you've turned your cat into a biohazardous (and stinky) norovirus vector, what do you do to clean it up?
Reptiles and infants don't mix
Garden veggies and poopy parasites
Eye Protection Urged For People With Tarantulas
Ear Mites -- "a little academic curiosity along with minimal squeamishness can provide some interesting information"

posted by cybercoitus interruptus (21 comments total)

tl;dr. We dead?
posted by mccarty.tim at 6:17 PM on August 2, 2010

McKenna has for some reason buried this useful advice in the appendix of her book:

Determining whether or not a MRSA infection is susceptible or resistant to a particular drug is an essential part of caring for MRSA infections, no matter where they occur or how serious they are. If you receive a prescription to treat MRSA, insist that your doctor discuss with you what names the drug is sold under, what drug family it belongs to -- and most important, what reasons your doctor has for believing that drug will be effective.

This advice might be applicable to Methicillin-sensitive S. aureus (MSSA) infections too, considering her latest blog entry.
posted by cybercoitus interruptus at 6:18 PM on August 2, 2010 [1 favorite]

...we want to increase awareness so people do a better job of things like washing their hands...

Operation Call Out That Guy In The Bathroom That Washes Insufficiently If At All is a GO
posted by DU at 6:18 PM on August 2, 2010

In addition to the FDA's Draft Guidance and the Judicious Use of Medically Important Antimicrobials in Food Producing Animals there is also some legislation proposed by upstate NY Congresswoman Louise Slaughter. Feel like reading some more? Enjoy this Huffington Post article.

Want to get involved? The Union of Concerned Scientists has some information.
posted by sciencegeek at 6:31 PM on August 2, 2010

"and covering their mouths properly when coughing or sneezing."

I'm never quite sure what to do when I cough or sneeze, if I don't have a tissue or something -- aren't I not supposed to bring my germy hands to my nose and mouth? I try to turn away and sneeze into my arm instead, and cleanup afterwards. Not the best way?
posted by catchingsignals at 6:48 PM on August 2, 2010

We should certainly ban anti-biotic abuse in livestock. I've waffled over how exactly this can be done, but most sorts of attempts would be better than the armageddon we're teetering towards now.

If it raises meat prices, well, that just happens to be a good in itself.
posted by grobstein at 7:05 PM on August 2, 2010

I'm never quite sure what to do when I cough or sneeze, if I don't have a tissue or something -- aren't I not supposed to bring my germy hands to my nose and mouth? I try to turn away and sneeze into my arm instead, and cleanup afterwards. Not the best way?

That is what the CDC recomends

Staphylococcus aureus infections were the cause of 5% - 6% of all deaths in the western world before the discovery of penicillin, which was itself discovered for the purpose of fighting staph infections. Multi-drug Resistant Staphylococcus aureus (MRSA) is nothing more than Staphylococcus aureus with a resistance to antibiotics, the only tools which have really made a difference in that percentage, or rather the promise of a return to the way things used to be. Whats funny though, the Republic of Georgia will be unaffected by developing resistance
posted by Blasdelb at 7:17 PM on August 2, 2010

The EU has already put similar controls into effect. In fact antibiotics were banned as growth promoters in 2006.
posted by sciencegeek at 7:18 PM on August 2, 2010

Fuck MRSA.

That is all.
posted by PROD_TPSL at 7:23 PM on August 2, 2010

Oh good, pretty much what I'm doing, thanks Blasdelb.
posted by catchingsignals at 7:24 PM on August 2, 2010

Yeah, they call that the vampire sneeze.
posted by maudlin at 7:43 PM on August 2, 2010 [2 favorites]

make everything copper...
posted by spish at 8:19 PM on August 2, 2010

Three logs of killing is impressive, but imagine how much it would cost hospitals to purchase the already ridiculously priced equipment multiplied by gimmick multiplied by the non-trivial nature of coating stuff with copper.

About Copper Development Association Inc.

The Copper Development Association is the information, education, marketing and technical development arm of the copper, brass and bronze industries in the USA.

Source: Copper Development Association Inc
posted by Blasdelb at 8:28 PM on August 2, 2010

Oregano oil
posted by hortense at 8:38 PM on August 2, 2010

Blasdelb: Multi-drug Resistant Staphylococcus aureus (MRSA) is nothing more than Staphylococcus aureus with a resistance to antibiotics, the only tools which have really made a difference in that percentage, or rather the promise of a return to the way things used to be.

I had the strong impression from reading observations like the following, that in the past couple of decades, various strains of MRSA and MSSA have developed more virulence than staph had historically presented:

One of the repeated themes in the 50-year evolution of MRSA has been its ability — all staph's ability — to promiscuously swap and share the bits of DNA that confer resistance and enhance virulence.

We have also reported an increased number and severity of invasive cases, e.g. complicated pneumonia, osteomyelitis, pyomyositis, myositis and severe sepsis syndrome associated with the predominance of clone USA300 [9,14-18]. Similar observations have been described at other institutions across the United States [19]. Recent reports suggest that USA300 is more virulent than other MRSA strains . . .

Sincere question: am I misreading you or these sources, or are these sources incorrect? Staph-related necrotizing pneumonia, pyomyositis, etc, typically occurred before penicillin use became widespread?
posted by cybercoitus interruptus at 1:25 AM on August 3, 2010 [1 favorite]

When I was admitted for my back surgery, the hospital did a nose swab to test for MRSA. Turns out, I'm a carrier. I got a nice, quiet private room for my stay. Yay, MRSA!

Seriously, though, the stuff is nasty scary. My son had a bout with it back in high school. A couple of days before the school band was to travel to Florida (to play at Disney), his index finger started swelling like a balloon. We got in to see a doctor right away. The doc took one look at it and sent my son straight into surgery to save the finger. He missed the band trip, but kept his finger.

Scary stuff.
posted by Thorzdad at 5:26 AM on August 3, 2010

FTFMe: typically occurred before penicillin use became widespread?

"Typically" doesn't belong there, of course. Pardon me.
posted by cybercoitus interruptus at 8:10 AM on August 3, 2010

As MRSA gets worse, the FDA discovers antibiotic abuse on factory farms
posted by homunculus at 11:47 AM on August 3, 2010 [1 favorite]

While pyomyositis which is commonly associated with poverty, tropical climates and HIV, ie: things which didn't get much attention prior to 1935, it was described. (You'll need to wade your way past phrases like "Africans are not different from any other humans, however, ..." to page 1214) Until recently it would not be terribly remarkable, being easily addressed with a simple round of I.V. antibiotics.

I just found a reference in my Robbins Basic Pathology (8th ed.) which confirms that Staphylococcus aureus, as well as Klebsiella pneumoniae and Streptococcus pyogenes, has been implicated in causing necrotizing pneumonia since the turn of the century. Additionally, the PVL toxin which your first paper describes as now being found in pneumonia was initially discovered by Van deVelde in 1894 and was named after Sir Philip Noel Panton and Francis Valentine when they associated it with soft tissue infections in 1932.

All of this makes sense, the mechanisms of antibiotic resistance are not associated with pathogenesis. However, MRSA is genuinely confusing. Staphylococcus epidermidus and hominis are perfectly healthy commensal bacteria which help you, and are rarely pathogenic, while S. aureus is very closely related but is more likely to become pathogenic. It is often yellow and produces coagulase, an enzyme helpful in pathogenesis.

It is easy for laymen, and apparently most journalists, to confuse pathogenesis with resistance. Commensal MRSA can acquire pathogenesis and pathogenic S. aureus can acquire multi-drug resistance, these are separate phenomena. The connection between the two is that pathogenesis has not been a problem for 70 years, except when combined with resistance (or comparatively rare circumstances).

tldr; Yes

(Full disclosure: I studied Staph Phage Lysate and the use of other staph pages in treating Staph related dog ear infections for a Spring and Summer)
posted by Blasdelb at 5:04 PM on August 3, 2010 [1 favorite]

Blasdelb, thank you for taking the time to write all that info out.

While pyomyositis which is commonly associated with poverty, tropical climates and HIV, ie: things which didn't get much attention prior to 1935, it was described. Staphylococcus aureus, as well as Klebsiella pneumoniae and Streptococcus pyogenes, has been implicated in causing necrotizing pneumonia since the turn of the century. Additionally, the PVL toxin [etc]

Sorry, I expressed myself poorly up there. "More virulent, and increasingly, atypically high numbers of occurrences of severe virulence" is what I meant, as in "Increased number and severity of invasive cases," linked above (written by medical types, not journalists). If I didn't misread that, then the ubiquity of broadly resistant, and severely virulent, S. aureus would not be a return to the way things were before the age of antibiotics. Because -- my thinking went -- before the age of penicillin, severe infections caused by severely virulent S. aureus were relatively uncommon, compared to the numbers that have been 1. popping up in the past couple of decades, and 2. afflicting healthy people not typically considered "at risk" -- immunocompromised, newborns / elderly, etc.

All of this makes sense, the mechanisms of antibiotic resistance are not associated with pathogenesis.

Yes, mentally working out the disconnect between what I thought I understood, and your observation, clarified that distinction for me! Thank you.

However, MRSA is genuinely confusing. Staphylococcus epidermidus and hominis are perfectly healthy commensal bacteria which help you, and are rarely pathogenic, while S. aureus is very closely related but is more likely to become pathogenic. It is often yellow and produces coagulase, an enzyme helpful in pathogenesis.

I occasionally came across references to commensal staph species (in fact, McKenna mentions a benign S. aureus strain that some doctors in the 1960s used to colonize a family suffering from pathogenic strains), but didn't know about coagulase, thank you.

It is easy for laymen, and apparently most journalists, to confuse pathogenesis with resistance.


I don't think McKenna's doing that, but I may very well have given that impression. And I'm not a medical type, so I could be entirely wrong about that assessment anyway.

The connection between the two is that pathogenesis has not been a problem for 70 years, except when combined with resistance (or comparatively rare circumstances).

High transmissibility is another (relatively new, I gather) factor.

I don't expect you to put any more time into answering than you already have, but if you happened to have the answer to this slightly off-topic question easily to hand...In all the stuff I've read, I haven't seen much about this question: why don't more people (or, any?) with chronic staph infections develop antibodies that can fight it off?
posted by cybercoitus interruptus at 5:38 PM on August 4, 2010

In other news: Scientists find new superbug spreading from India
posted by homunculus at 9:21 AM on August 11, 2010