Stress response and virulence in Salmonella Typhimurium: a genomics approach

Since 1995 the number of human infections with Salmonella serovar Typhimurium DT104 increased in The Netherlands and abroad. The multi antibiotic resistance of this strain has been often proposed as plausible reason for this increase. Within his PhD research, Armand Hermans found novel DT104 specific DNA, that is most likely involved in virulence and might be an additional reason for the DT104 increase. In addition, the possibility for DT104 to survive certain process- and product conditions has been studied in this genomics based research. A better survival of stress such as acid or heat treatment could be another additional explanation for the DT104 increase. To enlarge the current insights on this topic, the activities of stress survival and virulence genes were studied by using the microarray technology. During exposure of DT104 to different stresses, similar stress survival mechanisms were activated, while different virulence mechanisms were stress specific activated. Bacterial cell communication also may play a role in regulation of these genes.