xMAP technology is applicable for high-throughput, multiplex and simultaneous detection of different analytes within a single complex sample. xMAP multiplex assays are currently available in various nucleic acid and immunoassay formats, enabling simultaneous detection and typing of pathogenic viruses, bacteria, parasites and fungi and also antigen or antibody interception. As an open architecture platform, the xMAP technology is beneficial to end users and therefore it is used in various pharmaceutical, clinical and research laboratories. The main aim of this review is to summarize the latest findings and applications in the field of pathogen detection using microsphere-based multiplex assays.

In this study, a total of 175 samples of ready-to-eat vegetables, frozen vegetables and sprouted seeds originating in 10 states of the European Union and from 32 manufacturers were collected during a period of one year and examined for the presence of Listeria monocytogenes using standard culture methods and qPCR. In addition to these methods, isolation of Listeria monocytogenes was also carried out following a unified sample preparation for combined downstream use in culture and qPCR analysis. Standard culture and culture preceded by unified sample preparation, showed that L. monocytogenes was present in 6.9% and 11.4% of analyzed samples, respectively, in low numbers. Application of qPCR revealed only 2.3% of samples to be positive for L. monocytogenes in small quantities (less than 10 cells/gram). A statistically significant higher occurrence of L. monocytogenes was seen in frozen vegetables compared to ready to eat vegetables (p<0.01; Fisher's exact post-hoc tests with Bonferroni's correction) or sprouts (p<0.05; Fisher's exact post-hoc tests with Bonferroni's correction). Therefore, temperature abuse in food containing pieces of frozen vegetables without any processing such as cooking, may pose health risks, especially for sensitive individuals such as pregnant women, children, the elderly, and immunocompromised individuals.