Spread of a distinct Stx2-encoding phage prototype among Escherichia coli O104:H4 strains from outbreaks in Germany, Norway, and Georgia.
Shiga toxin 2 (Stx2)-producing Escherichia coli (STEC) O104:H4 caused one of the world's largest outbreaks of hemorrhagic colitis and hemolytic uremic syndrome in Germany in 2011. These strains have evolved from enteroaggregative E. coli (EAEC) by the acquisition of the Stx2 genes and have been designated enteroaggregative hemorrhagic E. coli. Nucleotide sequencing has shown that the Stx2 gene is carried by prophages integrated into the chromosome of STEC O104:H4. We studied the properties of Stx2-encoding bacteriophages which are responsible for the emergence of this new type of E. coli pathogen. For this, we analyzed Stx bacteriophages from STEC O104:H4 strains from Germany (in 2001 and 2011), Norway (2006), and the Republic of Georgia (2009). Viable Stx2-encoding bacteriophages could be isolated from all STEC strains except for the Norwegian strain. The Stx2 phages formed lysogens on E. coli K-12 by integration into the wrbA locus, resulting in Stx2 production. The nucleotide sequence of the Stx2 phage P13374 of a German STEC O104:H4 outbreak was determined. From the bioinformatic analyses of the prophage sequence of 60,894 bp, 79 open reading frames were inferred. Interestingly, the Stx2 phages from the German 2001 and 2011 outbreak strains were found to be identical and closely related to the Stx2 phages from the Georgian 2009 isolates. Major proteins of the virion particles were analyzed by mass spectrometry. Stx2 production in STEC O104:H4 strains was inducible by mitomycin C and was compared to Stx2 production of E. coli K-12 lysogens.
Federal Institute for Risk Assessment, Department of Biological Safety, Berlin, Germany. lothar.beutin@bfr.bund.de
Lothar
L
Beutin
Jens Andre
JA
Hammerl
Eckhard
E
Strauch
Jochen
J
Reetz
Ralf
R
Dieckmann
Ylanna
Y
Kelner-Burgos
Annett
A
Martin
Angelika
A
Miko
Nancy A
NA
Strockbine
Björn Arne
BA
Lindstedt
Detlef
D
Horn
Hella
H
Monse
Bruno
B
Huettel
Ines
I
Müller
Kurt
K
Stüber
Richard
R
Reinhardt
D000328:Adult; D000595:Amino Acid Sequence; D001435:Bacteriophages / Q000235:genetics*; D002648:Child; D004926:Escherichia coli / Q000378:metabolism*; D005260:Female; D005846:Georgia (Republic); D005858:Germany; D006801:Humans; D008242:Lysogeny; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D046529:Microscopy, Electron, Transmission / Q000379:methods; D016685:Mitomycin / Q000737:chemistry; D008969:Molecular Sequence Data; D017900:Myoviridae / Q000378:metabolism; D009664:Norway; D017422:Sequence Analysis, DNA; D022641:Shiga Toxin 2 / Q000378:metabolism*; D054323:Shiga-Toxigenic Escherichia coli / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D014771:Virion
D022641:Shiga Toxin 2; D016685:Mitomycin