3/13/2016 Learning Objectives Food 1.Use basic biochemical characteristics to identify Vibrio 2.Understand what conditions in foods favor Vibrio growth Chapter 17 AN INTRODUCTION 3.Recognize,from symptoms and time of onset,a case of foodborne illness caused bybro Vibrio species 4.Choose appropriate interventions(heat, preservatives,and formulations)to prevent the growth of Vibrio 5.Identify sources of the organism 6.Understand the role of Vibrio toxins and virulence factors in causing foodborne illness Outbreak Vibrios multiply rapidly Seafood Aficionados:"The only Low levels of V parahaemolyticus can way to eat certain seafood is raw" rapidly increase to an infectious level if 2006 and contaminated shellfish shellfish are not refrigerated rapidly after harvest ‘ia-8 e Proper storage temperatures must also Consumed contaminated be maintained during transport, shellfish processing,and storage Self-limiting illness with diarrhea,vomiting,and chills for 1-3 days 义
3/13/2016 1 Chapter 17 Vibrio species Learning Objectives 1. Use basic biochemical characteristics to identify Vibrio 2. Understand what conditions in foods favor Vibrio growth 3. Recognize, from symptoms and time of onset, a case of foodborne illness caused by Vibrio 4. Choose appropriate interventions (heat, preservatives, and formulations) to prevent the growth of Vibrio 5. Identify sources of the organism 6. Understand the role of Vibrio toxins and virulence factors in causing foodborne illness Outbreak Seafood Aficionados: “The only way to eat certain seafood is raw” 2006 and contaminated shellfish • 177 persons became ill with Vibrio parahaemolyticus • Consumed contaminated sh llfi h h ellfi s h • Self-limiting illness with diarrhea, vomiting, and chills for 1-3 days • Vibrios multiply rapidly • Low levels of V. parahaemolyticus can rapidly increase to an infectious level if shellfish are not refrigerated rapidly after harvest • Proper storage temperatures must also be maintained during transport, processing, d an storage
3/13/2016 Levels of total vibrios during 10 days of Raw oysters are consumed for storage at5°c,10°c,and20°c their taste old wives'tale-they act as an aphrodisiac 8 oysters contain hormone-inducing amino acids People rarely consider the hazards associated with eating raw oysters 10 Stoaage Time (days) +5PC量1护C2PC Outbreak Vibrios July-August,1997 .209 persons became ill with gastroenteritis after eating raw oysters Over 20 Vibrio species are described dmrcpsu. 12 cause disease in humans 8 are directly associated with food Culture confirmed V.parahaemolyticus Seafood consumption is strongly outbreak correlated with vibrio infections -<200 CFU per gram of oyster meat illness may occur at bacterial levels lower Vibrios are the dominate species in the than the current action level estuarine waters and are associated US and Canada permit the sale of oysters with with a variety of seafood <10 CFU per gram of oyster meat
3/13/2016 2 Levels of total vibrios during 10 days of storage at 5°C, 10°C, and 20°C • Raw oysters are consumed for - their taste - old wives’ tale - they act as an aphrodisiac - oysters contain hormone-inducing amino acids • People rarely consider the hazards associated with eating raw oysters Outbreak July - August, 1997 • 209 persons became ill with gastroenteritis after eating raw oysters • Symptoms: diarrhea, abdominal cramps, nausea, and vomiting • Culture confirmed V. parahaemolyticus outbreak - < 200 CFU per gram of oyster meat - illness may occur at bacterial levels lower than the current action level • US and Canada permit the sale of oysters with < 104 CFU per gram of oyster meat Vibrios • Over 20 Vibrio species are described • 12 cause disease in humans • 8 are directly associated with food • Seafood consumption is strongly correlated with vibrio infections • Vib i h d i i i h Vib rios are t h e dominate species i n t h e estuarine waters and are associated with a variety of seafood
3/13/2016 Changes in incidence of laboratory-confirmed Vibrios bacterial infections,U.S.,2010* Pathogen Decrease Increase 40%-60%of finfish and shellfish at Yersinia- -52% supermarkets may contain Vibrio species Vibrio 115用 V.parahaemolyticus and V.alginolyticus STEC50157一44%1 are the most commonly isolated Shigella—57%:■ Vibrios are associated with shellfish Salmonella ●3%1 during the summer months Listeria 38以1 Annual incidence increased 78%from the Campylobacter27% baseline endemic level during 1998-2006 -10080-604020020406080100 change compared Relative rates of laboratory-confirmed infections compared with1996-1998re Characteristics of Vibrios by year ce Network United States,1996-2012 ·Many enrichment broths for vibrios STEC015 have been developed ·Alkaline peptone water is most commonly used ·Coupled with growth on TCBS media thiosulfate-citrate- Vibrio cholerae (yellow)and Vibrio parahaemolyticus bile salts-sucrose (dark green on TCBS agar 2010 2012 agar
3/13/2016 3 Vibrios • 40% - 60% of finfish and shellfish at supermarkets may contain Vibrio species • V. parahaemolyticus and V. alginolyticus are the most commonly isolated • Vibrios are associated with shellfish during the summer months • Annual incidence increased 78% from the baseline endemic level during 1998-2006 Relative rates of laboratory-confirmed infections compared with 1996–1998 rates, by year —Surveillance Network, United States, 1996–2012 Characteristics of Vibrios • Many enrichment broths for vibrios have been developed • Alkaline peptone water is most commonly used • Coup g led with growth on TCBS media thiosulfate-citratebile salts-sucrose agar Vibrio cholerae (yellow) and Vibrio parahaemolyticus (dark green ) on TCBS agar
3/13/2016 Characteristics of Vibrios Epidemiology Oxidase test is used to differentiate sucrose Number of vibrios,particularly V.vulnificus positive Vibrio from Enterobacteriaceae and V.parahaemolyticus in surface waters Vibrios are oxidase positive or contain and shellfish correlate with seasonality cytochrome c Fig.2-Relationship betw erature and IFCO Characteristics of Disease Symptoms of the two most common Vibrio species differ Variation in the severities of Vibrio- associated diseases V.vulnificus illness Outcome depends on the person's underlying fever,chills,and nausea health Liver disease no diarrhea -Diabetes mortality:40%-60%of cases -GI disorders V.parahaemolyticus illness -Immune disorders diarrhea,abdominal cramps,nausea, -Long term steroid use Exceptions are V.cholerae O1 and 0139 as vomiting these bacteria infect non-compromised mortality:low people as well
3/13/2016 4 Characteristics of Vibrios • Oxidase test is used to differentiate sucrose positive Vibrio from Enterobacteriaceae - Vibrios are oxidase positive or contain cytochrome c tetramethyl-pphenylenediamine dihydrochloride Epidemiology • Number of vibrios, particularly V. vulnificus and V. parahaemolyticus in surface waters and shellfish correlate with seasonality Characteristics of Disease • Variation in the severities of Vibrio – associated diseases • Outcome depends on the person Outcome depends on the person s underlying ’s underlying health - Liver disease - Diabetes - GI disorders - Immun sor rs e disorders - Long term steroid use • Exceptions are V. cholerae O1 and O139 as these bacteria infect non-compromised people as well • Symptoms of the two most common Vibrio species differ V. vulnificus illness - fever chills and nausea fever, chills, and nausea - no diarrhea - mortality: 40% - 60% of cases V. parahaemolyticus illness - diarrhea abdominal cramps nausea diarrhea, abdominal cramps, nausea, vomiting - mortality: low
3/13/2016 Characteristics of Disease Vibrio vulnificus kills Sarasota man after swimming in Gulf-2014 Vibrios are part of the normal estuarine microflora -Shellfish sanitation programs are not useful in controlling Vibrio infections Essential that raw seafood be kept cold to prevent bacterial growth Essential that it be cooked properly before consumption VELOPING STORY 590 Susceptibility to Physical and Susceptibility to Physical and Chemical Treatments Chemical Treatments Very little is known about the effects of High hydrostatic pressure reduces the preservation techniques and inactivation of number of Vibrios with the additional vibrios advantage that it perfectly shucks oysters Sensitive to cold temperatures Various dried spices,herbs,tomato sauce, Seafood can be protected at refrigeration and organic acids exhibit bactericidal temperatures activities Thermal processing is effective at reducing Depuration of filter-feeding bivalves the number of Vibrios in food (pumping bacteria free water through the USDA recommends an internal temperature tissues)removes Salmone/la and E coli but of 60oc for several minutes to cook shellfish not Vibrio
3/13/2016 5 Characteristics of Disease • Vibrios are part of the normal estuarine microflora - Shellfish sanitation programs are not useful in controlling Vibrio infections - Essential that raw seafood be kept cold to prevent bacterial growth - Essential that it be cooked properly before consumption Vibrio vulnificus kills Sarasota man after swimming in Gulf - 2014 Susceptibility to Physical and Chemical Treatments • Very little is known about the effects of preservation techniques and inactivation of vibrios • Sensitive to cold temperatures • Seafood can be protected at refrigeration temperatures • Th l i i ff ti t d i Thermal processing is effective at reducing the number of Vibrios in food • USDA recommends an internal temperature of 60OC for several minutes to cook shellfish Susceptibility to Physical and Chemical Treatments • High hydrostatic pressure reduces the number of Vibrios with the additional advantage that it perfectly shucks oysters • Various dried spices, herbs, tomato sauce, and organic acids exhibit bactericidal activities • Depuration of filter-feeding bivalves (pumping bacteria free water through the tissues) removes Salmonella and E. coli but not Vibrio