TY - GEN T1 - EHEC/EAEC O104:H4 strain linked with the 2011 German outbreak of haemolytic uremic syndrome enters into the viable but non-culturable state in response to various stresses and resuscitates upon stress relief AU - Aurass, Philipp AU - Prager, Rita AU - Flieger, Antje AB - Various non-spore forming bacteria, including Escherichia coli, enter a dormant-like state, the viable but non-culturable (VBNC) state, characterized by the presence of viable cells but the inability to grow on routine laboratory media. Upon resuscitation, these VBNC cells recover both culturability and pathogenicity. In 2011, a large outbreak involving more than 3000 cases of bloody diarrhoea and haemolytic uremic syndrome was caused by an E. coli O104:H4 strain expressing genes characteristic of both enterohaemorrhagic (EHEC) and enteroaggregative E. coli (EAEC). The ability of the outbreak strain to enter the VBNC state may have complicated its detection in the suspected sources. In this paper, we investigated the ability of the outbreak strain to enter and subsequently recover from the VBNC state. We found that in a nutrient-poor micro-environment, various stresses such as toxic concentrations of copper ions or certain types of tap water are able to render the bacteria unculturable within a few days. Without copper ion stress, the majority of cells remained culturable for at least 40 days. Incubation with the stressors at 23°C compared with 4°C hastened this observed loss of culturability. The integrity of a considerable fraction of copper ion- and tap water 1-stressed bacteria was demonstrated by live/dead staining and microscopy. Relieving stress by copper-ion chelation facilitated resuscitation of these bacteria while preserving their fitness, major virulence gene markers (stx2, aggR, aggA genes) and specific phenotypes (ESBL resistance, autoaggregation typical for EAEC strains). KW - Humans KW - Disease Outbreaks KW - Germany/epidemiology KW - Virulence KW - Hemolytic-Uremic Syndrome/microbiology KW - Hemolytic-Uremic Syndrome/epidemiology KW - Escherichia coli Infections/microbiology KW - Escherichia coli Infections/epidemiology KW - Enterohemorrhagic Escherichia coli/pathogenicity KW - Copper/pharmacology KW - Culture Media/chemistry KW - Drinking Water/chemistry KW - Enterohemorrhagic Escherichia coli/drug effects KW - Enterohemorrhagic Escherichia coli/growth & development KW - Microbial Viability KW - 610 Medizin PY - 2011 LA - eng PB - Robert Koch-Institut, Infektionskrankheiten / Erreger VL - 13 IS - 12 DO - 10.1111/j.1462-2920.2011.02604.x ER -