Identification and characterisation of Escherichia coli strains of O157 and non-O157 serogroups containing three distinct Shiga toxin genes.
Three Shiga toxin (Stx)-producing Escherichia coli (STEC) strains from patients with diarrhoea were identified, each of which contained three distinct stx genes (stx1, stx2 and stx2c). The strains belonged to the serotypes O52:H19, O75:H- and O157:H- and harboured eae and EHEC-hly sequences. Colony-blot immunoassay was used to demonstrate that both major types of Stx were expressed. The association of stx genes with either phage or phage DNA was demonstrated in all three strains. Isolated phage DNA from all strains contained stx1 sequences, but stx2 sequences were found only in phage DNA of two of these strains. The presence of three distinct stx genes may enhance the virulence of STEC strains and should be monitored. The observations demonstrate not only the potential of stx genes to spread within different serotypes, but also their capacity to accumulate within a single strain.
Fürst
Sabine
S
Scheef
Jürgen
J
Bielaszewska
Martina
M
Institut für Hygiene und Mikrobiologie der Universität Würzburg, Josef-Schneider-Str. 2, 97080 Würzburg, Germany, *Institute of Medical Microbiology, 2nd Medical Faculty, Charles University, 150 06 Prague, Czech Republic and †Max von Pettenkofer-Institut für Hygiene und Mikrobiologie der Ludwig Maximilians Universität München, Pettenkoferstraße 9a, 80336 München, Germany.
Rüssmann
Holger
H
Institut für Hygiene und Mikrobiologie der Universität Würzburg, Josef-Schneider-Str. 2, 97080 Würzburg, Germany, *Institute of Medical Microbiology, 2nd Medical Faculty, Charles University, 150 06 Prague, Czech Republic and †Max von Pettenkofer-Institut für Hygiene und Mikrobiologie der Ludwig Maximilians Universität München, Pettenkoferstraße 9a, 80336 München, Germany.
Schmidt
Herbert
H
Karch
Helge
H
D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D002522:Chlorocebus aethiops; D003090:Coliphages / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis; D004279:DNA, Viral / Q000032:analysis / Q000737:chemistry; D003967:Diarrhea / Q000382:microbiology*; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology*; D019453:Escherichia coli O157 / Q000145:classification / Q000235:genetics / Q000472:pathogenicity; D005858:Germany; D006463:Hemolytic-Uremic Syndrome / Q000382:microbiology*; D006801:Humans; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012703:Serotyping; D022603:Shiga Toxins; D014709:Vero Cells; D010948:Viral Plaque Assay; D014774:Virulence
D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004279:DNA, Viral; D022603:Shiga Toxins