Biology Reference
In-Depth Information
administered with the probiotics preparation VSL#3 is effective at preventing
post-operative recurrence of CD, while
Saccharomyces boulardii
improves
the effect of mesalazine in the maintenance of remission (
Gionchetti et al.,
2006
). Commensal
E. coli
strain Nissle improves maintenance of steroid-
induced remission of colonic CD (
Malchow, 1997
) and is able to reduce the
ability of AIEC to adhere, invade and induce pro-inflammatory cytokines
(
Huebner et al., 2011
); however, it has no effect on the capacity of AIEC to
adhere to biopsies from CD or healthy ileum (
Jensen et al., 2011
).
SHIGA TOXIN-PRODUCING
E. COLI
O104:H4
Background
Definition and/or classification
Escherichia coli
O104:H4 is an infrequently isolated pathogenic
E. coli
sero-
type and the cause of the 2011 European diarrheal outbreak (
Mellmann et al.,
2011
). Analysis of genome sequences obtained from several outbreak isolates
showed that the
E. coli
O104:H4 strain is an enteroaggregative
E. coli
(EAEC;
for further details, see Chapter 8) that has acquired the Shiga toxin genes, pre-
sumably by bacteriophage transduction (
Brzuszkiewicz et al., 2011
;
Mellmann
et al., 2011
;
Rasko et al., 2011
;
Rohde et al., 2011
). Genome assembly con-
firmed two copies of the
stx2
prophage gene cluster; however, a set of additional
virulence and antibiotic-resistance factors are also characteristic of this
E. coli
O104:H4 outbreak strain.
History
In May-July 2011, two outbreaks of bloody diarrhea and hemolytic uremic
syndrome (HUS) occurred in Europe: one centered in Germany (around 4000
cases of bloody diarrhea, 850 cases of HUS and 50 deaths), and a much smaller
outbreak in southwest France (15 cases of bloody diarrhea, 9 of which pro-
gressed to HUS) (
Bielaszewska et al., 2011
;
Frank et al., 2011
;
Gault et al.,
2011
). Both outbreaks were caused by a Shiga toxin-producing
E. coli
(STEC)
strain of serotype O104:H4 (
Gault et al., 2011
;
Scheutz et al., 2011
). This was
not the first time this isolate was seen in Germany and the first isolates of
E. coli
O104:H4 carrying the Shiga toxin genes in this country date back to 2001, when
the prototype strain known as HUSEC41 isolate 01-0991 was recovered from
a HUS case (
Mellmann et al., 2008
;
Bielaszewska et al., 2011
;
Kunne et al.,
2012
).
E. coli
O104:H4 had been also isolated in 2006, from a woman who
contracted HUS in Korea and also from Italy in 2009 (
Scavia et al., 2011
). In
the case of the HUS-producing isolate from South Korea (
Bae et al., 2006
), the
strain appears not to be closely related to the German outbreak strain, differing
in their toxin gene carriage, antibiotic resistance properties, and pulsed-field gel
electrophoresis profiles (
Kim et al., 2011
).
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