TABLE 9.

Studies of MRSA carriage and infection in livestock animals and human contacts, 1993 to 2008

AnimalsYr of studyLocation(s)Major finding(s)Genotype(s) identifiedaReference(s)
Chickens2006BelgiumChickens on farms with cloacal or nasal MRSA colonizationST398-IVa or -V or nontypeable SCCmec/t011, ST398-III/t567663
2007BelgiumMRSA isolated from cloaca or nasal cavity of broiler chickenspa type t1456, ST398722
Cows2002-2004HungaryMilk samples from cows with subclinical mastitis and tonsillar swab culture of milk industry worker grew MRSA identical by PFGEST1-IVa/t127, PVL negative451
Horses1993-1994MichiganHorses with MRSA wound infections after procedures; 3 health care workers had nasal colonization with MRSA strains related by PFGENot stated817
2000-2002Ontario, CanadaAt a veterinary college and on 10 horse farms, MRSA isolates were obtained from screening cultures of the nares of horses and personnel as well as from sites of clinical infection; this yielded MRSA isolates from 79 horses and 27 personnel; a horse farm worker had the sole human infection; he had an MRSA SSTI complicating a tattoo wound; CMRSA-5 was isolated from him, and MRSA isolates identical by PFGE were recovered from 2 horses under his careCMRSA-5 by PFGE (related to USA500, carrying SCCmec type IV, spa type t007, PVL negative) accounted for 26/27 (93%) isolates from people and 76/79 (96%) of isolates from horses991
2004Ontario, CanadaA foal with MRSA arthritis and omphalophlebitis and its dam with MRSA nasal colonization were admitted to a veterinary hospital; health care workers who cared for the foal developed MRSA SSTIs, and 10/103 (9.7%) personnel had either nasal or groin colonization with MRSAPVL negative and identical by PFGE, CMRSA-5 (related to USA500)988
2004Liverpool, United Kingdom11/67 (16%) horses at a hospital had MRSA nasal or skin carriage; 3 others had clinical MRSA infections12 isolates from 7 horses had 5 PFGE types, all were PVL negative41
2008Hertfordshire, United Kingdom2 MRSA infections in horses at a veterinary college hospitalST398-IVa/t011, PVL negative552; A. Loeffler, personal communication
2003-2004IrelandHorses at 7 veterinary clinics and a hospital with MRSA wound infections or “abdominal granuloma”; horse strains related to those recovered from the nares of attendant veterinary personnelUnrelated to known clinical isolates held by a large Irish reference laboratory, all with identical or closely related PFGE types689
2002-2003Ontario, Canada, and New YorkFarm in Ontario with MRSA colonization in 9/53 (17%) horses and 1/10 (10%) personnel; farm in New York with MRSA colonization of 29/67 (43%) horses and 3/18 (17%) personnelNo information986
Not statedVienna, Austria2 horses with MRSA wound infectionsST398-IVa/t0111006
Not statedLower Saxony, GermanyFoal with MRSA sinusitisST398-V/t11971006
2002-2005Ontario, Canada69/3,372 (2.0%) horses upon admission to a teaching hospital had nasal MRSA colonizationNo information987
2007Belgium12/110 (10.9%) horses from Belgium, the Netherlands, France, and Luxemburg seen at a clinic had MRSA nasal colonizationST398-IVa/t011 (n = 10), ST398-V/t011 (n = 2), and ST398-IVa/t1451 (n = 1)932
2006-2007Vienna, AustriaMRSA infections among 25 horses at a university veterinary hospital; 18/131 (13.7%) personnel had MRSA colonizationHorse strains were ST1-IVa/t127 (n = 3), ST254-IVd/t036 (n = 15), and ST398-IVa/t011 (n = 7), and all were PVL negative; personnel strains were ST1-IVa/t127 (n = 2), ST254-IVd/t036 (n = 13), ST398-IVa/t011 (n = 2), and ST8-IVh/t008, and all were PVL negative198
2003-2004United Kingdom9 MRSA isolates from clinical infections of horsesspa-CC8 (n = 8) or related to EMRSA-15 (n = 1); spa types included t020, t036, t064, and t451625
PigsNot statedFrance5/112 (4.5%) pig farmers carried MRSA in the nasopharynx; none of 27 nonfarmer controls matched by age, sex, and county of residence carried MRSAST8 (n = 2), ST5 (n = 1), ST438 (n = 1), and ST398 (n = 1)27, 31
2008ChinaMRSA isolated from dust samples on 5/9 (56%) pig farms in Sichuan ProvinceST9/t899 or ST1376/t899, all PVL negative965
2008ChinaMRSA isolated from nares of 58/509 (11.4%) pigs and 2/13 (15%) pig farm workers in 4 Chinese provinces; none of 276 cattle, 47 cattle workers, or 107 slaughterhouse workers had nasal MRSA carriageST9/t899 (n = 46), ST912/t899 (n = 13), and ST1297/t899 (n = 1), all PVL negative197
2004-2005Netherlands3 family members on a pig farm (farm A) colonized with identical MRSA strains; at a university medical center, another farmer, a veterinarian, his son, and his son's nurse carried the same strain as above-described family; 1/30 (3.3%) pigs on farm A had perineal carriage of the same MRSA strain; at a meeting of regional pig farmers, 6/26 (23%) were colonized with MRSA in the throat and/or noseNone typeable by PFGE; spa type t108, t567, or t943961
2005NetherlandsA woman with MRSA mastitis and her daughter had MRSA nasal colonization; 3 family members and 3 coworkers on her pig farm had MRSA throat or nasal colonization, and 8/10 (80%) pigs on the farm had throat, nasal, or perineal colonizationAll isolates were ST398-V/spa t108, agr type 1, and PVL and TSST negative417
Not statedLower Saxony, GermanyMRSA colonization in 1 pig from a veterinary medical schoolST398-V/t0341006
2005-2006Netherlands209/540 (39%) pigs in 9 slaughterhouses had MRSA nasal colonization; transmission of MRSA both prior to arrival and at slaughterhouses was likelyST398 with SCCmec type III (n = 4), IVa (n = 41), or V (n = 59); spa types included t011, t108, t1254, t1255, t567, t034, and t943226
2005Singapore1/64 (1.5%) pigs used in exptl research, 1/50 (2%) pigs in a slaughterhouse, and 1/32 (3%) staff workers at an academic hospital's research facilities had MRSA nasal colonization2 isolates from pigs were ST398-V; 1 from a pig and 1 from a scientist were ST22-IV819
2006Netherlands35/310 (11%) pigs on 7/31 (23%) farms had MRSA nasal colonization; 11 MRSA-colonized personnel had strains with the same genotype as those of pigs on their respective farmsST398-IV or -V/t011, t108, t567, t899, and t1939, all PVL negative940
2005DenmarkS. aureus nasal carriage in 10/100 (10%) pigs; 1/10 (10%) were MRSA, and 9/10 (90%) were MSSAAll nontypeable by PFGE; spa type t034 (n = 9) or related t1793 (n = 1)35, 351
2004-2007DenmarkPigs tested after a person working or living on the farm presented with CC398 MRSA (i.e., spa type t034, t108, or t1793) infection or carriage; 23/50 (46%) pigs had nasal carriage of CC398 MRSAPigs carried CC398, spa type t034532
2007NetherlandsOn 50 farms, 33/232 (14%) pig farmers and their families had nasal colonization with MRSA, and either pigs had nasal carriage or fomites near pigs were contaminated with MRSA on 28/50 (56%) farms; on 15 farms with nasal colonization in people, animals and people had the same spa typeNo information931
2007-2008Iowa and IllinoisIn 2 farm systems, 49% (147/299) of swine and 45% (9/20) of farm workers had MRSA nasal carriage15 MRSA isolates from animals and workers were all ST398-V, PVL negative846; T. Smith, personal communication
Not statedOntario, Canada71/285 (24.9%) pigs on 20 farms had MRSA nasal or rectal colonization; 5/25 (20%) pig farmers had MRSA nasal carriage; on 5 farms with human colonization, concordant strain types were found in farmers and pigs59.2% of pig and human isolates had spa type t034 and could not be typed by PFGE; 10% of pig and 20% of human isolates were USA100471
2006NetherlandsMRSA SSTIs in 4 piglets on a breeding farm and 20 pigs on a supplier farm; MRSA nasal colonization in 2 farm workersST398-IV/t011937
2008Portugal4 pigs and 1 veterinarian from a pig farm had MRSA nasal carriage, and at a second farm, 3 pigs had MRSA nasal carriageFirst farm had ST398-V/t011, PVL negative; second farm had ST30-V/t021, PVL negative730
Rabbits2002-2003Pennsylvania1 rabbit with an ear infectionPVL+747
2003IrelandAt a clinic, MRSA wound culture from rabbit and MRSA nasal carriage in veterinary workerBoth isolates had the same PFGE type689
2003-2004Berlin, GermanyWound infection in a rabbit at a hospitalST22-IV, PVL negative969
Rats2008Belgium and Netherlands5/40 (12.5%) black rats (Rattus rattus) trapped at pig farms had MRSA throat colonizationST398/t011 (n = 4) and ST97/t1236 (n = 1), all PVL negative930
  • a MRSA composite strain genotypes are presented in the following format: MLST type-SCCmec type/spa type. For example, ST398-IVa/t011 indicates a MRSA strain that was ST398 by MLST, carried the SCCmec type IVa element, and was type t011 by spa typing.