Effect of exposure to stress conditions on propidium monoazide (PMA) - qPCR based enumeration of Campylobacter in broiler carcass rinses
Poster Oct 27, 2014
A. Duarte1,2*, N. Botteldoorn2 ,W. Coucke2, S. Denayer2, K. Dierick2, and M. Uyttendaele1
Campylobacter quantification by qPCR is unable to distinguish viable vs. dead cells in contrast to the culture-based ISO 10272-2 reference method. Propidium monoazide (PMA) has been used to overcome this disadvantage.
A Campylobacter PMA-qPCR enumeration method was developed, evaluated and compared to the culture-based enumeration for both artificially and natural contaminated broiler carcass rinses. The PMA effect was further evaluated on stressed cells. Five conditions, commonly encountered during the slaughter process and storage (acid, heat, cold, oxidation and freezing), were inflicted to the broiler carcass rinses artificially contaminated with Campylobacter jejuni or Campylobacter coli.
A better correlation between the reference method and the qPCR enumeration was obtained when PMA was used. Both cultured-based methods showed a significant CFU reduction for heat, cold and acid stresses although the PMA-qPCR enumeration showed that viable bacteria were underestimated. Freezing showed the highest reduction effect, while the reduction extend was also overestimated by the microbiological enumeration procedure. Exposure to mild oxidative stress was the only stress condition applied at temperatures permitting adaptation of Campylobacter and did not lead to either reduction in CFU nor in the PMA-qPCR signal.
The PMA-qPCR method showed that the culture-based enumeration is underestimated when cells are under stress.
Despite the developments in conventional PCR, the complexity of multiplex Real Time PCR is still limited due to the lack of sufficient detection channels. To achieve high-end multiplexing capacity on standard Real Time PCR machines, Anapa Biotech has developed the MeltPlex® technology (see box on right).READ MORE
Genome-wide association studies (GWAS) have identified more than 100 genetic loci associated with type 2 diabetes. The majority of these are located in the intergenic or intragenic regions suggesting that the implicated variants may alter chromatin conformation. This, in turn, is likely to influence the expression of nearby or more remotely located genes to alter beta cell function. At present, however, detailed molecular and functional analyses are still lacking for most of these variants. We recently analysed one of these loci and mapped five causal variants in an islet-specific enhancer cluster within the STARD10 gene locus. Here, we aimed to understand how these causal variants influence b-cell function by alteration of the chromatin structure of enhancer clusterREAD MORE
Early life stress (ELS) is highly associated with development of psychopathology
and mood disorders in adulthood. Genetic studies have identified variation in the gene calcium voltage-gated channel subunit alpha1C (CACNA1C) to increase risk for several psychiatric disorders. This poster assessed the expression of Cacna1c following prepubertal stress.
5th International Congress on Epigenetics & Chromatin
Aug 22 - Aug 23, 2019
International Conference on e-Health and Healthcare Innovations
May 08 - May 09, 2019
12th International Conference on Cancer Stem Cells and Oncology Research
Jul 18 - Jul 19, 2019
4th Annual Congress on Nanomedicine and Drug Delivery
Apr 04 - Apr 06, 2019