Occurrence and genetic diversity of Arcobacter spp. in a spinach-processing plant and evaluation of two Arcobacter-specific quantitative PCR assays

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• 作者：Lena Hausdorf ; Maria Neumann ; Ingo Bergmann ; Kerstin Sobiella ; Kerstin Mundt ; Antje Fr&ouml ; hling ; Oliver Schl&uuml ; ter ; Michael Klocke ; ^{mklocke@atb-potsdam.de}
• 关键词：OTU ; operational taxonomic unit ; qPCR ; quantitative PCR ; IAC ; internal amplification control ; PCR ; polymerase chain reaction ; LOD ; limit of detection ; LOQ ; limit of quantification ; ASM ; Arcobacter-selective medium
• 刊名：Systematic and Applied Microbiology
• 出版年：2013
• 出版时间：June, 2013
• 年：2013
• 卷：36
• 期：4
• 页码：235-243
• 全文大小：735 K

文摘

Some species of the genus m>Arcobacterm> are considered to be emerging food pathogens. With respect to recent vegetable-borne outbreaks, the aim of this work was to investigate the occurrence and diversity of m>Arcobacterm> within the production chain of a spinach-processing plant by a combination of cultivation and molecular methods. Samples including spinach, water, and surface biofilm were taken over a period of three years from the entire processing line. Ten 16S rRNA (m>rrsm>) gene clone libraries were constructed and analysed using amplified rRNA gene restriction analysis (ARDRA). Approximately 1200 clones were studied that resulted in 44 operational taxonomic units (OTUs). Sequences with high similarities to m>Arcobacter cryaerophilusm> (13 % of clones, 3 OTUs), m>A. ellisiim> (4 % , 6 OTUs), m>A. suism> (15 % , 3 OTUs), and the type strain of m>A. nitrofigilism> (1 % , 7 OTUs) were identified. This represents the first report of the detection of the recently described species m>A. ellisiim>, m>A. suism> and, in addition, m>A. venerupism> from alternative habitats. A total of 67 % of the clones (22 OTUs) could not be assigned to a genus, which indicated the presence of uncharacterised m>Arcobacterm> species.

For the cultivation-independent detection of m>Arcobacterm>, two genus-specific quantitative PCR (qPCR) assays were developed and tested on 15 m>Arcobacterm> species. When these assays were applied to samples from the spinach-processing plant, they showed positive results for up to 35 % of the samples and supported the conclusion that there is a considerable risk for the transfer of pathogenic m>Arcobacterm> species on vegetables, which was also verified by a cultivation approach.