Action 2.3 Hazard evaluation

Hazard evaluation
Action 2.3 Hazard evaluation
- The aim of this action was to assess the risks associated with the presence of
pathogenic microorganisms in rivers, marine waters and shellfish in the Region.
Occurrence of bacteria and enteric viruses
potentially pathogenic for humans and detection
of Microbial Source Tracking markers in
environmental waters and shellfish from Brittany,
France
- January 2013 to March 2015
- 6 partners in the France (Channel) – England
- 8 sites in UK and France
Context
Hazard evaluation- French sites
- Faecal contamination on the river catchment and marine bacteria in
the sea
- Coastal activities
OBJECTIVES :
Manure spreading
- To evaluate the presence of pathogenic microorganisms and faecal indicators in
selected shellfish-harvesting areas and their catchment in France
Direct discharge
Enteric bacteria and viruses
Run-off
Human activities
Bovine breeding
WWTP
- To identify the origins of the faecal contamination in these sites using Microbial
Source Tracking markers
Porcine breeding
- To characterize the strains of enteric pathogens isolated from different sites and
matrices (shellfish, waters, superficial sediments)
Marine bacteria
Bathing and fishing areas
Sanitary
Risks
Shellfish harvesting areas
Presence of bacterial and viral pathogens in the coastal environment
Economic consequences: closure and/or declassification of shellfishharvesting and bathing areas
Health risks: infections and shellfish outbreaks
Context
Shellfish-borne outbreaks in France
Brittany
From 1996 to 2010:
About 3.25 million inhabitants
561 of the 11,261 food-borne outbreaks due to shellfish (5%)
Higher human population in summer on the coastline
Diarrheic Shellfish
poisonning (26%)
Other pathogens (4%)
Vibrio
parahaemolyticus (3%)
Enteric viruses (54 %)
Vaillant et al., 2012, BEH
35% of French bovine production
56% of French porcine production
On only 7% of the total area of France
Staphylococcus aureus (4%)
Salmonella spp (8 %)
Mainly noroviruses
Largest national farming region
60% of the surface area used for agriculture
Clostridium perfringens (1%)
- 2,730 km of coastline (40% of the French coastline)
- 116 km of shellfish-harvesting areas
- 558 km of bathing areas
Brittany site: « la baie de la Fresnaie »
- Catchment: 121 km 2; 4 main rivers
- About 9,000 inhabitants
Sampling on the site « La Fresnaie »
and livestock farming
- Shellfish-farming area (oysters and mussels) and recreational shellfish-harvesting area
(cockles)
Sampling on « La Fresnaie »
The main rivers
Sampling on « La Fresnaie »
Sampling of shellfish
- Sampling of river samples
Bacteria, viruses and MST markers
- Faecal bacteria indicators: E. coli and enterococci
Used in the regulations – classification of bathing and shellfish –harvesting areas
No discrimination of fecal sources
Bacteria, viruses and MST markers
- Microbial Source Tracking markers
Identification of faecal sources: human, bovine and pigs
- bacterial markers: host-associated Bacteroidales markers
- chemical markers: stanols
- Enteric bacteria and viruses
Potential pathogens – Health risk
Salmonella, Campylobacter, pathogenic E. coli
Norovirus
- Marine bacteria
Potential pathogens – Health risk
Vibrio parahaemolyticus, V. cholerae (non choleric), V. vulnificus
Identification of the origin of faecal sources
Microbial analyses in the laboratory
Microbial Source Tracking markers
- Water filtration and shellfish preparation
• Human, porcine and bovine potential
sources of contamination for the 4 main rivers
• Water stanol fingerprints and Bacteroidales
markers from monthly samplings (2-year
mean):
- Analyses by culture methods
• Frémur: Mixed (human, bovine and pig)
• Le Rat: Bovine
• Le Clos: Mixed mainly Human
• Kermiton: Bovine
• Shellfish: only few positive results
Shellfish
- Analyses by molecular methods
Presence of noroviruses in shellfish
Presence of potentially pathogenic enteric bacteria
201313– 2014
February
February 14
Salmonella
Isolation of Salmonella strains
Water
22.9%
Shellfish
1.7%
Sediment
0%
Campylobacter
March 14
April 13
April 14
May 13
May 14
June 13
June 14
July 13
July 14
August 13
August 14
September 13
September 14
October 13
October 14
November 13
November 14
December 13
December 14
January 14
January 15
Clams
Absence
Not analyzed
Shellfish
22 (22%) of 99 shellfish batches positive for norovirus, mainly from January to April
Presence of Vibrio in shellfish and marine waters
Preliminary conclusions (1/2)
V . cholerae non-O1/non-O139
Coc kle s
22%
Sea wa ter
28%
V. parahaemolyticus
Cockles
17%
Seawa te r
20%
-
Faecal contamination (E. coli ) was observed in water and shellfish with
difference according to the type of sample and the sampling date and site
-
Microbial Source Tracking (MST)
- Human (HF183)-, Ruminant (Rum2Bac)- and also Pig (Pig2Bac)associated Bacteroidales markers were detected at a quantifiable level in the
rivers of the catchment in Brittany
- Obtention of human, bovine and pig stanol fingerprints
-
Identification/detection of MST markers and enteric bacterial pathogens in
the same samples.
Mussels
22%
Oysters
28%
V. vulnificus
üThe 3 main Vibrio spp. involved
in human infections are present
on both sites and in all matrices
Mussel 2
Presence
Presence of
Campylobacter
(strains)
in samples (%)
Isolation of Campylobacter strains (about 1200 isolates)
Water
87.5%
Shellfish
39.1%
Sediment
33.3%
üThree Vibrio spp. detected in
over 65% of the seawater or
shellfish samples and only when
the water temperature is over
15°C (June to October)
March 13
Oyster 2
Mussel 1
Oyster 1
Mussels
30%
Oyste rs
33%
Cockles
22%
Sea wa ter
15%
Oysters
26%
Musse ls
37%
üV. parahaemolyticus most
isolated species (over 50% of the
isolates are potentially pathogenic
for humans – presence of
hemolysin)
Preliminary conclusions (2/2)
Analyses still undergoing
- Data analysis concerning Microbial Source Tracking markers
-
Campylobacter represents the most frequently detected enteric bacterial
pathogen in water and shellfish samples from theses sites
-
Presence of norovirus in shellfish during epidemic period
-
Detection of pathogenic Vibrio spp. In waters and shellfish
- Comparison of host-associated Bacteroidales and stanol fingerprints
and relation of these two MST markers with information on human
population and animal production from the catchment
- Comparison of the presence of MST markers (Bacteroidales) found in
Normandy and UK
- Characterization of bacterial strains (enteric and Vibrio spp.)
- Typing and comparison with strains isolated in Normandy
- Genome sequencing and comparison with isolates from Normandy and
UK (V. parahaemolyticus)
- Ligand expression of noroviruses in French and UK oysters
Outputs for the Region
- Better knowledge on the presence of bacteria and viruses in a selected
catchment and shellfish–harvesting area – variable according to the time/season
of sampling and to the meteorological conditions - important data in terms of risk
evaluation
- Identification of the main sources of faecal contamination in the rivers – MST
tools now available
- Comparison of shellfish-harvesting areas in France and UK
LSEM, Brest and Nantes, LER Dinard
Gourmelon M.,
Charlotte Balière, Marie-Paule Caprais, ,
Joelle Cozien,Dominique Hervio-Heath,
Céline Hubert, Jean-Claude Le Saux,
Solen Lozach,
Emmanuelle Quenot,
CNRS Géosciences, Rennes
Emilie Jardé,
Loic Harrault, Laurent Jeanneau,
Patrick Petitjean
Soizick Le Guyader,
Sylvain Parneaudeau,
Sofia Strubbia
Pascal Garry,
Antoine Véron
Julien Chevé
EHESP, Rennes
Cyrille Harpet, Michèle Legeas
Thank you for your attention!
Contact: Michele.Gourmelon@ifremer.fr
Université de Caen
Alain Rincé,
Quentin Bruey, Clémence Balière,
Jean-Christophe Giard,
Isabelle Rincé