MRSA Strain 398 » General

ST398 MRSA in dogs

admin — Thu, 01 Jul 2010 07:25:36 +0000

A study we just published in the journal Veterinary Record Floras et al, 2010 described an MRSA outbreak in a dog breeding kennel. That's a little unusual in itself, but considering how MRSA is spreading amongst the dog population, it's not really astounding. What was unique about this outbreak was the strain that was involved, sequence type 398 ST398.ST398 MRSA is commonly referred to as livestock-associated MRSA, since this strain seems to have originated in pigs, and is commonly found in pigs and calves in some regions. It can also infect people, and high rates of carriage of this MRSA strain can be found in pig farmers, pig vets and other people with close contact with livestock. In some areas of Europe, this strain is a big problem, accounting for a large percentage of human infections. Interestingly, it seems to be a rare cause of illness in people in North America at least at the moment.

via Livestock-associated MRSA in dogs : Worms and Germs Blog.

Pigs to give MRSA back in more aggressive form?

admin — Tue, 05 Jan 2010 11:26:34 +0000

There is a concern that the numbers of MRSA or other antimicrobial-resistant bacteria might increase further when human isolates become established in animals, as this can amplify the numbers of such bacteria by dissemination within animal groups with subsequent spread back to humans. Certain antimicrobials have been implicated in the selection of MRSA, ESBL-producing bacteria and predisposition to infection by C. difficile. Guidelines for treatment and prevention of infections by MRSA, ESBL-producing bacteria and C. difficile were discussed and evidence-based policies were recommended for both humans and animals.

via Antimicrobial-resistant pathogens in animals and man: prescribing, practices and policies « InfectoNews – Jorge Omar Calabrese.

Kristof on MRSA ST398: Good, but There’s Better Evidence

admin — Wed, 18 Mar 2009 16:33:30 +0000

This well known science blogger suggest we not be too tentative about ST398.

I’m always loath to criticize mainstream discussions of the antibiotic resistance, particularly when the link between antibiotic use in agriculture and antibiotic resistance is raised. But, while NY Times columnist Nicholas Kristof meant well, he missed the mark.

In his column about MRSA ST398, he describes things that might happen. Here’s one example:

Public health experts worry that pigs could pass on the infection by direct contact with their handlers, through their wastes leaking into ground water (one study has already found antibiotic-resistant bacteria entering ground water from hog farms), or through their meat, though there has been no proven case of someone getting it from eating pork. Thorough cooking will kill the bacteria, but people often use the same knife to cut raw meat and then to chop vegetables. Or they plop a pork chop on a plate, cook it and then contaminate it by putting it back on the original plate.

The problem I have with Kristof’s column is that MRSA ST398 isn’t a hypothetical. The reason the spread of MRSA ST398 into the healthcare system scares the crap out of me isn’t that it might happen: it’s already happened. We already have documented evidence from the Netherlands, where ST398 has started to show up in the healthcare system in agricultural regions of the country. And in Sweden, ST398 is present in the community.

via Mike the Mad Biologist : Kristof on MRSA: Good, but There’s Better Evidence.

MRSA ST398 story emerges again in mainstream media

admin — Wed, 18 Mar 2009 16:13:14 +0000

Kristof blames the overuse of antibiotics in healthy animals for the antibiotic resistance in both people and animals:

[T]he central problem here isn’t pigs, it’s humans. Unlike Europe and even South Korea, the United States still bows to agribusiness interests by permitting the nontherapeutic use of antibiotics in animal feed. That’s unconscionable.

The Pultizer-prize-winning Kristof is no foe of farmers. He grew up on a farm and has tuned in to food. He called for a Secretary of Food rather than a Secretary of Agriculture and followed-up after Vilsack’s appointment suggesting a Deputy Secretary of Food.

Still, over at ScienceBlogs Mike the Mad Biologist says there’s better evidence:

The problem I have with Kristof’s column is that MRSA ST398 isn’t a hypothetical. The reason the spread of MRSA ST398 into the healthcare system scares the crap out of me isn’t that it might happen: it’s already happened. We already have documented evidence from the Netherlands, where ST398 has started to show up in the healthcare system in agricultural regions of the country. And in Sweden, ST398 is present in the community.

These are countries with reasonably good antibiotic use policies, so I’m not exactly optimistic. I’m glad Kristof raised the issue, but the reflexive conservative denialists will attack the column, when he could have provided much stronger evidence.

via MRSA ST398 & the Overuse of Nontherapeutic Antibiotics.

MRSA Common in Farm Animals?

admin — Mon, 01 Sep 2008 11:22:02 +0000

Seems that 398 is not the only MRSA strain found in animals. This is not new knowledge but it would be interesting to persue the possibility that pigs are the mixing bowl for some of the recombinations that are blighting human health.

The agar diffusion method was used to compare the antimicrobial activity of B. subtilis NB-6, B. megaterium NB-3, B. mallei NB-8 and C. kutscheri NB-1 against methicillin-resistant S. aureus (MRSA) isolated from meat samples from sheep, bovine, camel and poultry in Amman area, Jordan. As shown in Table 1, substances produced by B. mallei NB-8 showed good antimicrobial activity against MRSA 2, MRSA 3, MRSA 5 and MRSA 13, and weak antimicrobial activity against MRSA 1, MRSA 7 and MRSA 8, while no antimicrobial activity against MRSA 6. MRSA 2, MRSA 5 and MRSA 8 were inhibited by substances produced by C. kutscheri NB-1. The other MRSA strains (MRSA 1, 3, 6, 7 and 13) were not inhibited at all. All MRSA strains were not inhibited by substances produced by B. subtilis NB-6 and B. megaterium NB-3 except MRSA strain 13 which was slightly inhibited by B. megaterium NB-3 produced substances.

S. aureus is an important cause of a variety of diseases in human and animals worldwide (Gilot and Leeuwen, 2004). Their ability to cause diseases in associated with several pathogenic factors including extracellular enzymes and toxins (Lee, 2003). Both animal and human isolates are generally resistant to penicillins (Seguin et al., 1999). Several reports suggest that the transfer of S. aureus between human and cattle is possible and that the infection of human by transmission through food products contaminated with animal MRSA is very plausible (Lee, 2003; Kaszanyitzky et al., 2003). Romero-Tabarez et al. (2006) has previously reported an antimicrobial activity of substances produced by B. subtilis (soil isolate) against multidrug resestant bacterial pathogen including methicillin-resistant S. aureus.

Bioline International Official Site (site up-dated regularly).