prevalence and molecular characteristics of vibrio species in pre ...

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10 According to Feldhusen (2000), indigenous bacteria found at low levels in seafood pose an insignificant hazard to the public health if the product is cooked adequately. But a few bacteria associated with faecal contamination of seafood (Salmonella, Campylobacter, Listeria, Yersinia, E. coli) continue to cause a large scale health threat through seafood consumption. This is worse when people have traditions of eating raw or under cooked seafood like in Japan. Food borne diseases lead to a significant morbidity and mortalities annually, even in developed countries where food safety is well regulated. In the United States seafood ranked third on the list of products that cause food borne illnesses during 1983- 1992 (Lipp and Rose, 1997). Over the past 20 years 4% of shell fish associated outbreaks were from bacterial pathogens of faecal contamination, while naturally occurring bacteria accounted for 20% of shellfish-related illnesses and 99% of deaths. Most of the indigenous bacteria belong to the genera’s of Vibrio, Aeromonas and Plesiomonas (Lipp and Rose, 1997). The Center for Disease Control and Prevention (CDC) estimates that approximately 76 million new cases of food-related illnesses and resulting 5,000 deaths and 325,000 hospitalizations occur in the United States each year (Group, 2010). Food borne illnesses has a significant impact on the economics of the public and private sectors. A calculation of precise figures for the economic impact is difficult with a high incidence of food borne related illnesses. The evaluation of cost at a national level in Canada and United States based on the available data showed that company losses and legal action are much higher than the medical/ hospitalization expenses, lost income or investigational costs. It was estimated that one million acute bacterial food borne illnesses occur in Canada and 5.5 million cases in US cost nearly $1.1 billion and $7 billion, respectively every year (Todd, 1989). FDA estimates the economic impact of food borne illnesses from health related costs by the sum of medical cost and losses to quality of life (loss of life expectancy, pain and suffering functional disability). Using CDC data, reports estimate that food borne illness costs related to produce alone are almost $ 39 billion per year in the US (Group, 2010). In Australia there has been an increasing incidence of food borne illnesses caused by E. coli O157:H7, Campylobacter, Salmonella, Hepatitis A,
11 Listeriosis, and other pathogens. Annual estimated costs for these food borne outbreaks and illnesses is Au. $ 2.46 billion (Khandaker and Alauddin, 2005). Consumer safety and the economic impact due to food borne pathogens in the seafood forced the importing countries to impose microbiological criteria on seafood. Each year the major importing countries of fish and fish products reject or detain imports due to the presence of microbial pathogens. For the European Union, Vibrio spp. and Salmonella accounted for 66% of the detention of imports during 1992-2002 and shrimp was dominant among seafood products that cause detention cases. FDA categorized the presence of Salmonella, Listeria, Shigella, Hepatitis A and general term bacteria on seafood detention (FAO, 2005). Regulatory requirements for the absence of Salmonella has been established for cooked/ ready to eat and raw shrimp in EU, Australia, New Zealand, US and Hong Kong, while ICMSF suggests that Salmonella should not be detected in 25g raw or cooked shrimp (Wan Norhana et al., 2010). Rejection of imports causes financial losses to the export countries. 2.5 Prevalence of Vibrio in the shrimp production chain Vibrio species are indigenous to the marine and estuarine environment (Bhaskar et al., 1998) and their presence in the shrimp production chain is to be expected. Several studies done in shrimp producing countries showed the prevalence of Vibrio in shrimp culture environments and also the retail marketed shrimps (Table 3). Only a few Vibrio species isolated are pathogenic to human and some are pathogenic to the shrimp itself. Gopal et al. (2005) investigated the prevalence of Vibrio in on the east and west coast of India and found Vibrio in water, shrimp and sediment samples. Vibrio alginolyticus (3-19%) V. parahaemolyticus (2-13%) V. harveyi (1-7%) and V. vulnificus (1-4%) were the predominant species found. The V. cholera found was negative for the cholera toxin and from V. parahaemolyticus, 2 out of 47 isolates were tdh positive and one contained the trh gene. Similarly, in a study done in Karnataka, India, by Bhaskar et al. (1998), all samples of sediment, water, shrimp, clam meat and formulated feed were contaminated with Vibrio spp. Vibrio alginolyticus was the most commonly isolated species found in shrimp and sediment. V. cholerae was found at a very low level but frequently in formulated feed.
Page 1 and 2: 2.1 Shellfish culture CHAPTER II LI
Page 3 and 4: 7 constant over the years while cul
Page 5: 9 Pathogenic bacteria associated wi
Page 9 and 10: Coastal water Shrimp Bangladesh (Co
Page 11 and 12: Table 4: Cholera pandemics Pandemic
Page 13 and 14: 17 parahaemolyticus should be Kanag
Page 15 and 16: 19 2.7.2 Biochemical characteristic
Page 17 and 18: 21 2.7.4 Genotypic characteristics
Page 19 and 20: 23 Clinical strains of V. parahaemo
Page 21 and 22: 2.8 Human pathogenic Vibrio 2.8.1 V
Page 23 and 24: 27 Vibrio spp. display similar bioc
Page 25 and 26: 29 host and effluent from the conta
Page 27 and 28: 31 elimination of Edwardsiella tard
Page 29 and 30: A. Cooling and freezing 33 Rapid an
Page 31: 2.10.3 Consumer education 35 Consum

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