Case study: Shiga Toxin-producing

Escherichia coli (STEC), insight on hybrid types

Parma Summer School 2020

“One Health”

Date: 9-10 June 2020

Meeting venue: Virtual event

Pathogenic Escherichia coli

STEC

Meningitis

Septicemia

EIEC

ExPEC

DEC

Emorrhagic Diarrhea

Adehsion/colonization

90%

Recovery

5-7 days

10%

HUS

Action of Stx on the kidney’s

endothelium

STEC: Pathogenesis of infections

2-4 days

Ingestion

1-2 days

Abdominal Cramps, diarrhea Stx in blood– Action on the colonic endothelium

Toxins

E-hly

Adhesion

toxB

Pathogenic E. coli: Genomic Complexity

toxins

AB BB A

B BB

Mobile genetic Elements:

• Bacteriophages

•Genomic Islands (PAI)

• Plasmids

LEE

OI-122

OI-57

AB BB

Gene pool

AEEC

aEPEC

tEPEC

STECsptAB

LEE; Ehly

LEE

LEE

Stx

Ehly

LEE

pEAF

STECsptC StxSubAB; tia, saa

EhlyespP

STECOD

cfa; elt, est

Stx

f4; elt, est

ETEC

Stx-ETEC

Stx

EA-ETECaggR; elt

EAECaggR; aaf; aaiC; aatA

Stx-EAEC

Stx

ExPEC

Stx-ExPEC

Stx

pap; iroN; iss

EIECpic; sepA, sigA

pINV

pINV

Stx

Shigella

Hybrid E. coli types can emerge from the E. coli Continuum

Stx-producing EAEC: The first cross patotypepathogenic E. coli

3,842 cases

2987

non-HUS STEC

18 deaths

(0.6%)

855

HUS

35 deaths

(4.1%)

Of HUS cases,- 68% women

- Median age 42 years (0-91 years)- Bloody diarrhoea in 79%

Stx-producing EAEC O104:H4, Germany 2011

ST-EAEC O111:H108 HUS

1992France

2012

Northern IrelandST-EAEC O111:H21

1 HUS

ST-EAEC O104:H4850 HUS

2011Germany, France

2009ST-EAEC O104:H41 HUS Italy

2010Finland

ST-EAEC O104:H41 HUS

ST-EAEC O104:H41 HUS

2001Germany

Stx-producing Enteroaggregative E. coli (ST-EAEC)

2013Italy

ST-EAEC O127:H44 HUS

ST-EAEC O86:NM1 HUS

2000Japan

STEC Hybrid Pathogroups in the NGS era

E. coli Infection: Epidemiology

✓ Entero-toxigenic E. coli (ETEC)

✓ Eentero-invasive E. coli (EIEC)

✓ Entero-aggregative E. coli (EAEC)

✓ Entero-patogenic E.coli (EPEC)

✓ Extra-intestinal Pathogenic E. coli (ExPEC)

inter–human Cycle

Oral–fecal Transmission

But foodborne transmission

is also suspected/ascertained

✓ Shiga-toxin-producing E.coli (STEC)

Zoonotic Cycle

Food-borne Transmission

Person to person also

reported

Food of animal origin

STEC a zoonotic pathogen

For hybrid types of pathogenic E. coli to emerge, contacts between strains from human and animal source is necessary

Soil Surface waters

Environmental lead

How does the overlapping between human and zoonotic bacteria occur?

• Municipal sewage sludge: Sewage sludge refers to the residual, semi-solid material that is produced as a by-product during sewage treatment of industrial or municipal wastewater. Increasingly used in agriculture as TSI

• Reclaimed water: Used in agriculture

• Contamination of recreational waters

• Urbanization of water streams

• Lack of safe water (increases the gene pool)

Human and zoonotic E.coli

The CogWheel

Crops production management

Social disparity

Clean water availability

Animal farming

Patient’s treatment

Prevention

Food security

Wastes management

Thank you for your attention