Whole-Genome Sequencing to Detect Numerous Campylobacter jejuni Outbreaks and Match Patient Isolates to Sources, Denmark, 2015-2017

Whole-Genome Sequencing to Detect Numerous Campylobacter jejuni Outbreaks and Match Patient Isolates to Sources, Denmark, 2015–2017 Scientific publication financially supported by ORION/One Health European Joint Programme (grant agreement nos. 773830)

Comparison of Danish Isolates of <i>Salmonella enterica</i> Serovar Enteritidis PT9a and PT11 from Hedgehogs ( <i>Erinaceus europaeus</i> ) and Humans by Plasmid Profiling and Pulsed-Field Gel Electrophoresis

ABSTRACT During the years 1994 to 1998, 10 strains of Salmonella enterica serovar Enteritidis phage type 11 (PT11) and 6 PT9a strains were isolated from Danish hedgehogs, together with 7 strains that did not yield phage susceptibility patterns conforming with any known phage type (routine dilution no conformity [RDNC]). From 1995 to 1998, five Danish patients were reported infected with serovar Enteritidis PT11 and two with PT9a. All serovar Enteritidis PT11, PT9a, and RDNC isolates from hedgehogs and humans were analyzed by pulsed-field gel electrophoresis (PFGE), plasmid profiling, and restriction fragment length polymorphism (RFLP) of plasmids. By use of S1 nuclease and Hin dIII, the PT11 and PT9a isolates had identical plasmid profiles and RFLP patterns, which differed from the RDNC profiles. The PFGE profiles were identical for all serovar Enteritidis PT11 and PT9a strains from hedgehogs, four of five human strains of serovar Enteritidis PT11, and two human strains of serovar Enteritidis PT9a, irrespective of restriction enzyme, whereas the last human strain deviated slightly when Not I was used but not when Xba I or Spe I was used. The results indicate that serovar Enteritidis PT9a and PT11 are closely related and that PT11 and PT9a from Danish hedgehogs and humans belong to the same clonal lineage. </jats:p