Christian Jenke

Publications of Christian Jenke

• Identification of Intermediate in Evolutionary Model of Enterohemorrhagic Escherichia coli O157.

  Authors: Christian Jenke, Shana R Leopold, Thomas Weniger, Jörg Rothgänger, Dag Harmsen, Helge Karch, Alexander Mellmann

  Emerging infectious diseases. 04/2012; 18(4):582-8.

  Highly pathogenic enterohemorrhagic Escherichia coli (EHEC) O157 cause a spectrum of clinical signs that include diarrhea, bloody diarrhea, and hemolytic uremic syndrome. The current evolutionaryHighly pathogenic enterohemorrhagic Escherichia coli (EHEC) O157 cause a spectrum of clinical signs that include diarrhea, bloody diarrhea, and hemolytic uremic syndrome. The current evolutionary model of EHEC O157:H7/H(-) consists of a stepwise evolution scenario proceeding from O55:H7 to a node (hypothetical intermediate) that then branches into sorbitol-fermenting (SF) O157:H(-) and non-SF (NSF) O157:H7. To identify this hypothetical intermediate, we performed single nucleotide polymorphism analysis by sequencing of 92 randomly distributed backbone genomic regions of 40 O157:H7/H(-) isolates. Overall, 111 single nucleotide polymorphisms were identified in 75/92 partial open reading frames after sequencing 51,041 nt/strain. The EHEC O157:H7 strain LSU-61 from deer occupied an intermediate position between O55:H7 and both O157 branches (SF and NSF O157), complementing the stepwise evolutionary model of EHEC O157:H7/H(-). The animal origin of this intermediate emphasizes the value of nonhuman reservoirs in the clarification of the evolution of human pathogens.

• Comparison of multilocus variable-number tandem-repeat analysis and multilocus sequence typing for differentiation of hemolytic-uremic syndrome-associated Escherichia coli (HUSEC) collection strains.

  Authors: Christian Jenke, Björn Arne Lindstedt, Dag Harmsen, Helge Karch, Lin Thorstensen Brandal, Alexander Mellmann

  Journal of clinical microbiology. 08/2011; 49(10):3644-6.

  Multilocus variable-number tandem-repeat analysis (MLVA) was compared to multilocus sequence typing (MLST) to differentiate hemolytic uremic syndrome-associated enterohemorrhagic Escherichia coliMultilocus variable-number tandem-repeat analysis (MLVA) was compared to multilocus sequence typing (MLST) to differentiate hemolytic uremic syndrome-associated enterohemorrhagic Escherichia coli strains. Although MLVA--like MLST--was highly discriminatory (index of diversity, 0.988 versus 0.984), a low level of concordance demonstrated the limited ability of MLVA to reflect long-term evolutionary events.

• Phylogenetic analysis of enterohemorrhagic Escherichia coli O157, Germany, 1987-2008.

  Authors: Christian Jenke, Dag Harmsen, Thomas Weniger, Jorg Rothganger, Eija Hyytia-Trees, Martina Bielaszewska, Helge Karch, Alexander Mellmann

  Emerging infectious diseases. 04/2010; 16(4):610-6.

  Multilocus variable number tandem repeat analysis (MLVA) is a subtyping technique for characterizing human pathogenic bacteria such as enterohemorrhagic Escherichia coli (EHEC) O157. We determinedMultilocus variable number tandem repeat analysis (MLVA) is a subtyping technique for characterizing human pathogenic bacteria such as enterohemorrhagic Escherichia coli (EHEC) O157. We determined the phylogeny of 202 epidemiologically unrelated EHEC O157:H7/H- clinical isolates through 8 MLVA loci obtained in Germany during 1987-2008. Biodiversity in the loci ranged from 0.66 to 0.90. Four of 8 loci showed null alleles and a frequency < or =44.1%. These loci were distributed among 48.5% of all strains. Overall, 141 MLVA profiles were identified. Phylogenetic analysis assigned 67.3% of the strains to 19 MLVA clusters. Specific MLVA profiles with an evolutionary persistence were identified, particularly within sorbitol-fermenting EHEC O157:H-.These pathogens belonged to the same MLVA cluster. Our findings indicate successful persistence of this clone.