[Fwd: PRO/AH> Staph. aureus (MRSA), human, porcine - Canada, USA]

[Guest guest]

Just received this...hoping it has absolutely *nothing* to do with this

list...but, given recent discussions....

--- PRO/AH> Staph. aureus (MRSA), human, porcine - Canada, USA

Date: Fri, 9 Nov 2007 16:04:23 -0500 (EST)

From: ProMED-mail <promed@...>

Reply- promedNOREPLY@...

promed-ahead@...

STAPH. AUREUS (METHICILLIN-RESISTANT), HUMAN, PORCINE - CANADA, USA

***********************************************************

A ProMED-mail post

<http://www.promedmail.org>

ProMED-mail is a program of the

International Society for Infectious Diseases

<http://www.isid.org>

Date: Tue 6 Nov 2007

Source: All Headline News (AHN) Media Corp [edited]

<http://www.allheadlinenews.com/articles/7009072481>

A new study published in Veterinary Microbiology found

methicillin-resistant _Staphylococcus aureus_ (MRSA) is widely common

in Canadian pig farms and pig farmers, signaling to some that animal

agriculture as a source of the deadly bacteria. The Veterinary

Microbiology study (Khanna et al. Veterinary Medicine 2007) is the

1st to show that North American pig farms and farmers commonly carry MRSA.

Researchers looked for MRSA in 285 pigs in 20 Ontario farms and found

MRSA at 45 percent of farms (9/20) and in nearly one in 4 pigs

(71/285). One in 5 pig farmers studied (5/25) also were found to

carry MRSA, a much higher rate than in the general North American

population. The strains of MRSA bacteria found in Ontario pigs and

pig farmers included a strain common to human MRSA infections in Canada.

A study published last month [October 2007] in the Journal of the

American Medical Association (JAMA) (Klevens et al: Invasive

methicillin-resistant _Staphylococcus aureus_ infections in the

United States JAMA 2007; 298: 1753-1771) estimated almost 100 000

MRSA infections in 2005, and nearly 19 000 deaths in the United

States. In comparison, HIV/AIDS killed 17 000 people that year.

With the recent outbreak of the deadly disease researchers generally

believed MRSA as an opportunistic infection occurring mainly in

hospitals. However more information is coming to light that finds

even healthy people are developing MRSA infections and pig farms may

be a possible culprit. Now some experts in the in the medical,

agriculture, and environmental industries are calling for Congress to

compel the US Food and Drug Administration (FDA) to study whether the

use of human antibiotics in animal agriculture is contributing to the

reported surge in MRSA infections and deaths in the United States.

" Identifying and controlling community sources of MRSA is a public

health priority of the 1st order, " said Wood, Executive

Director of Food Animal Concerns Trust and Steering Committee Chair

of Keep Antibiotics Working. " Are livestock farmers and farms in the

United States also sources? We don't know for sure, because the US

government is not systematically testing US livestock for MRSA. "

" Last summer, when we raised the MRSA issue, the FDA told us that it

had no plans to sample US livestock to see if they carry MRSA, " said

Wallinga, MD, Director of the Institute for Agriculture and

Trade Policy's Food and Health Program. " Given the latest science

that hog farms may generate MRSA, we need Congress to give FDA and

other relevant agencies the necessary funding and a sense of urgency.

Sampling needs to be done as soon as possible. "

In Europe, MRSA has been shown to be transmitted from pigs to

farmers, their families, veterinarians, and hospital staff treating

farm-infected patients. The same pig strain that was detected in

Canada has been associated in Europe with serious human illness

including skin, wound, breast, and heart infections, as well as pneumonia.

Proposed federal legislation, The Preservation of Antibiotics for

Medical Treatment Act, sponsored by Senate Health Committee Chairman

Kennedy (D-MA) and Senators Olympia Snowe (R-ME),

(R-ME), Sherrod Brown (D-OH), and Jack (D-RI) in the

Senate (S. 549) and Rep. Louise Slaughter (D-NY), the only

microbiologist in Congress, and 34 other House members in the US

House of Representatives (H.R. 962), would phase out the use of

antibiotics that are important in human medicine as animal feed

additives within 2 years.

[byline: Ayinde O. Chase]

--

Communicated by:

ProMED-mail Rapporteur Marshall

[Reports of MRSA infection and colonization in companion animals and

their human owners have appeared in the past few years (see

<http://www.infectiousdiseasenews.com/200606/darwin.asp>), as well as

have reports of MRSA in service dogs in nursing homes where MRSA is

endemic

(<http://www.newsday.com/news/health/ny-hspets295437222oct29,0,7605571.story>)

and in horses and people who work with the horses (see ProMED-mail

20070108.0076).

The transmission of MRSA from people to animals has been described as

an example of a " reverse zoonosis " (see ProMED-mail 20011225.3111 and

20011223.3103). MRSA has been described in other domestic animals

such as cats, cattle, sheep, chickens, and rabbits

(<http://www.medvetnet.org/cms/templates/doc.php?id=106>).

_S. aureus_ has been isolated from 66 percent of 444 samples of raw

chicken meat from 131 of 145 supermarkets in 47 prefectures

throughout Japan (S. Kitai et al, J Vet Med Sci 2005; 67: 107-10).

The frequency of MRSA isolation was, however, low -- only 2 of the

292 isolates were MRSA, which contained the SCCmec (staphylococcal

cassette chromosome mec) type IV gene (prevalent in

community-acquired MRSA) and belonged to a biovar that is

characteristic of strains of human origin. This suggested to the

authors that the 2 MRSA isolates were transmitted incidentally by

workers handling raw chicken meat during processing. The authors

stated that MRSA had not been previously isolated from samples of

chicken, beef, or pork meat.

Similarly in Korea, among 1913 specimens collected from the animals,

421 contained _S. aureus_; but only 28 of these contained _S. aureus_

resistant to concentrations of oxacillin higher than 2 microgm/ml.

Isolates from 15 of the 28 specimens were positive by PCR (polymerase

chain reaction) for the mecA gene, confirming that they were MRSA. Of

the 15 mecA-positive MRSA isolates, 12 were from dairy cows and 3

were from chickens. The authors found that genotype of 6 of the MRSA

isolates from animals were identical to the patterns of certain

isolates from humans. (JH Lee et al. Appl Environ Microbiol 2006; 69:

6489-6494).

In contrast in Europe, a high percentage of Dutch pig farms (85

percent) had pigs that carried MRSA and 39 percent of slaughtered

pigs carried MRSA (deNeeling et al. Vet Microbiol 2007; 122: 366-72

and van Duijkeren et al. Vet Microbiol. 2007 Jul 25; [Epub ahead of

print]). In addition, in Europe, MRSA has been shown to spread from

pigs to farmers, their families and hospital staff treating

farm-infected patients (Witte et al Emerg Infect Dis 2007; 13: 255-8,

Huijsdens et al. Ann Clin Microbiol Antimicrob 2006; 5: 26-9, and

Voss et al. Emerg Infect Dis 2005; 11: 1965-6).

Khanna et al (Methicillin-resistant _Staphylococcus aureus_

colonization in pigs and pig farmers. Veterinary Microbiology

doi:10.1016/j.vetmic.2007.10.006) are the 1st to show that North

American (Ontario) pig farms and farmers commonly carry MRSA. The

news release does not state whether there is a genetic relationship

between the human and pig MRSA isolates, although it states that

these strains " included a strain common to human MRSA infections in

Canada. " However, the Khanna et al article states that there was a

correlation between the presence of MRSA in pigs and humans on farms

and that the predominant spa type in pigs and humans was type 539 and

related strains, and that these spa types found in Canada as having

" previously been reported as being clonal complex (CC) 398 (Witte et

al., 2007) " in Europe. The 2nd most common spa type was type 2,

" classified as Canadian epidemic MRSA-2 (CMRSA-2), also known as

USA-100, " the most common community-associated MRSA strain in humans

in Canada. The link between MRSA in the food animals and its presence

in the community is disturbing, although more information is needed. - Mod.ML]

[see also:

Staph. aureus (MRSA), comm. acq., human, equine - Canada 20070108.0076

2001

----

MRSA: reverse zoonosis - USA, Canada (02) 20011225.3111

MRSA: reverse zoonosis - USA, Canada 20011223.3103

2000

----

Methicillin-resistant Staph. aureus, dogs - Canada (02) 20000803.1300

Methicillin-resistant Staph. aureus, dogs - Canada 20000802.1286

1997

----

Methicillin-resistant _Staphylococcus aureus_ - Canada 19970320.0586]

....................................ml/mj/dk

*##########################################################*

************************************************************

ProMED-mail makes every effort to verify the reports that

are posted, but the accuracy and completeness of the

information, and of any statements or opinions based

thereon, are not guaranteed. The reader assumes all risks in

using information posted or archived by ProMED-mail. ISID

and its associated service providers shall not be held

responsible for errors or omissions or held liable for any

damages incurred as a result of use or reliance upon posted

or archived material.

************************************************************

Become a ProMED-mail Premium Subscriber at

<http://www.isid.org/ProMEDMail_Premium.shtml>

************************************************************

Visit ProMED-mail's web site at <http://www.promedmail.org>.

Send all items for posting to: promed@...

(NOT to an individual moderator). If you do not give your

full name and affiliation, it may not be posted. Send

commands to subscribe/unsubscribe, get archives, help,

etc. to: majordomo@.... For assistance from a

human being send mail to: owner-promed@....

############################################################

############################################################