02436nas a2200289   4500000000100000000000100001008004100002260007000043653001900113653001900132653002900151653001000180653001200190100001800202700001300220700001700233700001200250700001300262700001700275700001800292700001400310245014500324300001200469490000800481520164300489022001402132       2014                            d  c10/2014bSchlütersche Verlagsgesellschaft mbH & Co. KGaHannover10apig production10aanimal farming10aantimicrobial resistance10aCTX-M10aE. coli1 aC v. Salviati1 aA Friese1 aN Roschanski1 aH Laube1 aB Guerra1 aA Käsbohrer1 aL Kreienbrock1 aU Roesler00aExtended-spectrum beta-lactamases (ESBL)/AmpC beta-lactamases-producing Escherichia coli in German fattening pig farms: a longitudinal study  a412-4190 v1273 aThe presence of ESBL/AmpC-producing Enterobacteriaceae in healthy livestock, such as pigs, was frequently reported worldwide in the last years. The development and potential spread of these resistant microorganisms in farm animals is discussed critically. Therefore, the main objectives of this longitudinal study were to determine potential sources and prevalence dynamics of ESBL/AmpCproducing Escherichia coli in seven German ESBL/AmpC-positive conventional fattening pig farms in the course of the fattening period. Samples tested were taken at three different times within one finishing fattening period and included 20 individual faeces samples as well as various samples of the animals’ housing environment such as pooled faeces, boot swabs, dust and environmental swabs. In individual faeces average carriage levels of 45%, 29% and 36% at the three sampling times were accompanied by decreasing faecal counts from 2.97 x 104 cfu/g at the first to 2.17 x 103 cfu/g at the third visit. In the animals’ housing environment 47.6% of pooled faeces and boot swab samples respectively and 5.9% of environmental swabs but none of the dust samples were tested positive. Altogether 228 E. coli isolates were analysed by combination disc tests, PCR and partly via sequencing. Thereby, a novel gene blaTEM-206 was detected. This study shows different detection levels of ESBL/AmpC-producing E. coli amongst the different farms and in the course of the fattening period. Pooled faeces and boot swab samples but not dust samples seem to be appropriate to assess the herd status of pigs with respect to ESBL/AmpC-producing Escherichia coli.   a0005-9366