Unexpected Sequence Types in livestock-associated methicillin-resistant (MRSA): MRSA ST9 and a Single Locus Variant of ST9 in pig farming in China

Jaap A. Wagenaar , Hua Yue , Jane Pritchard , Marian Broekhuizen-Stins , Xander Huijsdens , Dik J. Mevius , Thijs Bosch , Engeline van Duijkeren

In October 2008 nine farrow-to-finish pig farms were visited in Shuangliu County in Sichuan Province, China. One farm was empty for one month but not cleaned after depopulation. Dust samples were collected at each farm and analysed for the presence of methicillin-resistant (MRSA). Dust samples from four farms were also analysed for the presence of methicillin-susceptible (MSSA). On 5/9 farms MRSA was isolated and on 2/4 farms MSSA was isolated. On two farms, including the empty farm, no MRSA or MSSA could be detected. All MRSA isolates (n=43) belonged to type t899. MSSA isolates belonged to type t899 (n=12) and type t034 (n=2). From 4/9 farms the MRSA isolates of type t899 were assigned to multilocus sequence type (MLST) ST9 whereas on one farm the MRSA type t899 isolates belonged to a single locus variant of MLST ST9 (ST1376). MSSA isolates with type t899 belonged to MLST ST9 and the MSSA with type t034 belonged to MLST ST398.

Mots clés: Methicillin-resistant; MRSA; Pigs; Pig farms

Jaap A. Wagenaar, Hua Yue, Jane Pritchard, Marian Broekhuizen-Stins, Xander Huijsdens, et al.. Unexpected Sequence Types in livestock-associated methicillin-resistant (MRSA): MRSA ST9 and a Single Locus Variant of ST9 in pig farming in China. Veterinary Microbiology, 2009, 139 (3-4), pp.405. ⟨10.1016/j.vetmic.2009.06.014⟩. ⟨hal-00526936⟩