Enterohaemorrhagic E. coli Hybrid Pathotype O80:H2

an emerging clone in France

E. Loukiadis1, P. Mariani-Kurkdjian2, S. Ganet1, P. Fach3, M.Bruyand4, S. Bonacorsi2

11th annual workshop of the NRL for E. coli in the EU

Rome, 11 November 2016

1. VetAgro Sup Campus Vétérinaire de Lyon, Laboratoire LMAP/LNR STEC, Lyon, France

2. CNR associé Escherichia coli, Service de Microbiologie, AP-HP, Hôpital Robert-Debré, Service de Microbiologie,

Université Paris Diderot, IAME, UMR 1137, Université Paris Diderot, Sorbonne Paris Cité, France

3. ANSES, Plateforme Identity Path, Maisons-Alfort, France

4. Santé Publique France, St Maurice, France

Introduction

• In 2012, we isolated an atypical EHEC from HUS patient’s blood culture

• This strain belongs to the rare serotype O80:H2 and harbors EHEC and ExPEC

virulence genes

French epidemiology of HUS in children < 15 years

1996 - 2015

http://www.invs.sante.fr/Dossiers-thematiques/Maladies-infectieuses/Risques-infectieux-d-origine-alimentaire/Syndrome-hemolytique-et-

uremique/Donnees-epidemiologiques-du-SHU-chez-l-enfant-age-de-moins-de-15-ans-en-France

• 2015: 111 cases of pediatric HUS were notified to the surveillance system.

Incidence rate: 0,94 cases /105 children (3,1 cases /105 in <3 years old)

Année Nombre de cas de SHU

Incidence annuelle

Année Nombre de cas de SHU

Incidence annuelle

1996 81 0,66 2006 104 0,87

1997 92 0,75 2007 74 0,62

1998 76 0,59 2008 112 0,94

1999 93 0,76 2009 109 0,91

2000 79 0,64 2010 122 0,99

2001 74 0,61 2011 162 1,32

2002 73 0,60 2012 145 1,20

2003 80 0,66 2013 152 1,22

2004 87 0,72 2014 117 0,99

2005 122 1,01 2015 111 0,94

Total 2065 0,8

• Five foodborne outbreaks were detected leading to control measures.

Outbreaks in France , 2005 -2015

SF O157:H7/O177:H25

O157:H7

http://www.invs.sante.fr/Dossiers-thematiques/Maladies-infectieuses/Risques-infectieux-d-origine-alimentaire/Syndrome-hemolytique-et-

uremique/Donnees-epidemiologiques-du-SHU-chez-l-enfant-age-de-moins-de-15-ans-en-France

Important shift in STEC serogroups causing HUS in France

• O157: 66% of patients in the period 1996-2005 / 23 % in 2015

• O26 : 13% of patients in the period 1996-2005 / 11 % of cases in 2015

• O80 is emerging: rise from 3% (2006-2010) to 35% in 2015 (most frequent

STEC serogroup identified in stools of HUS cases in 2015)

STEC serogroups identified

1996 -2015

0%

10%

20%

30%

40%

50%

60%

70%

O157

O26

O80

http://www.invs.sante.fr/Dossiers-thematiques/Maladies-infectieuses/Risques-infectieux-d-origine-alimentaire/Syndrome-hemolytique-et-

uremique/Donnees-epidemiologiques-du-SHU-chez-l-enfant-age-de-moins-de-15-ans-en-France

Pediatric HUS related to EHEC O80 in France, 2005-2015

• 58 cases of pediatric HUS related to STEC O80 infection reported

since 2005, rising from 3% to 35% in 2015

0123456

JFMAMJ JASONDJFMAMJ JASONDJFMAMJ JASONDJFMAMJ JASONDJFMAMJ JASONDJFMAMJ JASONDJFMAM

2010(n=5)

2011(n=1)

2012(n=6)

2013(n=12)

2014(n=10)

2015(n=14)

2016(n=4)

Nbre of cases

• Median age: 16 months

Q1: 2 months – Q3: 24 months

Min 2 months; Max 9 years

• Gender

Female: 34 (59%)

Male: 24 (41%)

Age group

N %

0-2 50 86

3-5 6 10

6-10 2 4

11-14 0 0

Pediatric HUS related to EHEC O80 in France, 2005-2016

Geographical repartition

Soycal, EID, 2016

Regional 10 year cumulative incidence rate of HUS

CLINICAL AND BIOLOGICAL CHARACTERISTICS

• HUS preceeded by diarrhea in 46 (79%) instances, 16 bloody (27,5%)

Median duration of diarrhea: 5 days (Q1: 3; Q3: 9)

Median blood creatinine: 89 µmol/L (Q1: 43; Q3:268)

Haemoglobinemia: median 6 g/dL (Q1: 5; Q3: 8)

Blood platelet count: median 37000 /mm3 (Q1: 23000; Q3: 63000)

• Blood transfusion required in 58% (n=34)

• 33 % acute dialysis support (n=19), 23 % long term renal sequelae(n=13)

• 17% neurological complications (n=10)

• 3,4 % died (n=2)

• 3 Unusual HUS:

- 1 relapse complicated by bacteremia

- 1 died after myocardial complication with pancreatic abscess

- 1 died (septic choc with intestinal necrosis and peritonitis)Soycal, EID, 2016

Genetic characterization of O80:H2 strains

EHEC virulence profile

• stx2 : 100% (no stx1)

�subtypes: 62% stx2c 2d,

22% stx2a

9% stx2d

7% stx2a 2d

• eae : 100%

� rare variant eae ξ: 100%

• ehx: 87%

Soycal, EID, 2016

Genetic characterization of O80:H2 strains

ExPEC (pS88) virulence profile

• > 4 genes : 100% : sitA, cia, hlyF, ompT

• iss, iroN (salmochelin) : 98%

• cva: 96%

• iucC (aerobactin) and etscC : 61%

Peigne et al, Infect Immun, 2009

O80:H2 : hybrid pathotypeSoycal, EID, 2016

RepPCR typing

O80

O1

57

O1

04

O1

21

O

11

1

Soycal, EID, 2016

H H BP

BH

- Amoxicillin : 93% R

- Cotrimoxazole : 74 % R

- Nalidixic acid : 89% R

Antimicrobial resistance

Azithromycin MIC90 : 4 mg/L.

57 % multidrug R

None ESBL

Soycal, EID, 2016

Epidemiological information on O80 pediatric HUS

• 5 HUS cases related to an outbreak in 2005 linked to raw milk

cheese consumption

• 2 HUS cases among a family (twin sister)

• Diarrhea among the relatives in 15 (28%) instances

• Risk exposures reported by 54 cases

- Raw milk consumption: 4 (7%)

- Cheese made with raw milk: 12 (22%)

- Ground beef: 18 (33%)

- Contact with farm animals: 12 (22%)

Not conclusive

Soycal, EID, 2016

O80:H2 STEC strainshave been isolated in food

• France (in 2012 and 2014)Cow-origin foodstuffs (not epidemiologically related)

?

• O80:H2 strains have also been isolated from animals (stx-)From a cow (Spain) (Blanco et al., JCM, 2004)

From a pig (Spain, the pig-origin strain was actually isolated in Slovakia) (Vu-Khac H et al., 2007)

O80:H2 STEC strainshave been isolated in food

• Food O80:H2 STEC isolates

→ « Chance » discovery (not screened in routine)

Which prevalence in food?

1st official monitoring plan in 2017in raw minced beef

Hybrid pathotype O80:H2has been isolated in food

Same virulence profile as human ones

EHEC-associated genesIncluding: stx2a

eae ξehxA

+ExPEC-associated genesUp to 7 pS88-encoded genes : sitA, cia, hlyF, ompTiss, iroN, cva,

O80:H2 : an hybrid pathotype

Hybrid pathotype O80:H2has been isolated in food

Same virulence profile as human ones

EHEC-associated genesIncluding: stx2a

eae ξehxA

+ExPEC-associated genesUp to 7 pS88-encoded genes : sitA, cia, hlyF, ompTiss, iroN, cva,

O80:H2 : an hybrid pathotype

Same antibioresistance profile as human ones

Resistant to amoxicillin, kanamycin, and nalidixic ac id

Soycal, EID, 2016! The 2 animal AEEC strains from the Spanish collection have a differentprofile (ehxA and pS88 negative) and are not multidrug resistant

N= 290 (2010-2012)

(146 human and 123 animal strains + 9 reference

strains + 9 « non pathogenic » E. coli)

French O80:H2 STEC strains belong to the ST301 (CC165)Wirth et al. , 2006

Hybrid pathotype O80:H2has been isolated in food

Cow-origin O80:H2 strains belong to the sameclonal group as humans ones

Same genetic profile than human ones

Soycal, EID, 2016O80:H2

RepPCR typing

Bv STECBv AEEC

Pig

AEEC

Confirmed by PFGE analysisOngoing WGS analysis of STEC

CONCLUSION

• Ongoing surveillance of this emerging atypical strain in France

• Therapeutic challenge: role of antibiotics?

• O80:H2 in others European countries ?

• Reservoir and source of infection for STEC O80:H2?

AcknowledgmentsThe French Society of Pediatrics and the French Ministry of Agriculture for its support of this study.J Blanco, NRL E. coli, SpainDr. Soysal ,Assistance Publique–Hôpitaux de Paris (AP-HP), FranceM Gouali, French NRC, Institut Pasteur, FranceAll the NCR and NRL teams