**4. Occurrence in fish and fishery product**

*Salmonella* has been isolated from fish and fishery product, though it is not psychrotrophic or indigenous to the aquatic environment (Mol et al., 2010). The relationship between fish and *Salmonella* has been described by several scientists; some believe that fish are possible carriers of *Salmonella* which are harbored in their intestines for relatively short periods of time and some believe that fish get actively infected by *Salmonella*. The organism was never recovered from the flesh of the fish, but was isolated from viscera and epithelium (Pullela, 1997). Most outbreaks of food poisoning associated with fish derive from the consumption

Salmonella in Fish and Fishery Products 95

*S*. Abaetetu + +

*S*. Agona + + +

*S*. Anatum + + + + + +

*S*. Arizonae + + + +

*S*. Baguida +

*S*. Bredeney +

*S*. Bullbay +

*S*. Cerro + +

*S*. Enteritidis + + + + + +

*S*. Hadar + + + +

*S*. Bareilly + +

*S*. Cannstat +

**Eastern Caribbean Europe and Russia Mexico Middle East** 

**North** 

**America/** 

**Multiple**

**South** 

**America** 

**Serotype India/ SE Asia Africa Central America Central pacific**

*Salmonella*

*S*. Aberdeen +

*S*. Anfo +

*S*. Atakpam + *S*. Augusten +

*S*. Biafra + *S*. Blockley +

*S*. Bradford + *S*. Braender + *S*. Brancast +

*S*. Brunei +

*S*. Drypool + *S*. Dublin +

*S*. Emek + *S*. Emek +

*S*. Farmsen + *S*. Gallinaru + *S*. Georgia +

*S*. Havana

*S*. Bovis-mobificans + +

*S*. Carrau +

*S*. Derby + +

*S*. Duesseldorf +

*S*. Gwaai +

*S*. Havana + +

*S*. Harmelen +

*S*. Ahepe + *S*. Albany +

of raw or insufficiently heat treated fish and cross-contamination during processing and about 12% of the foodborne outbreaks related to consumption of fish are caused by bacteria including *Salmonella* (Huss et al., 2000; Aberoumand, 2010). Similarly, The U.S. Food and Drug Administration's (FDA) data showed that *Salmonella* was the most common contaminant of fish and fishery products (Allshouse et al., 2004). Up to 10-15% of fish samples from India and Mexico were positive of *Salmonella* which has also been detected in several crustacean and molluscan products from India and Malaysia (Huss & Gram 2003). *Salmonella* contamination in fish and fishery products has also been reported from other countries like Thailand, Hong Kong, Spain and Turkey (Herrera et al., 2006; Kumar et al., 2009; Pamuk et al, 2011). The highest *Salmonella* incidence in fishery products was determined in Central Pacific and African countries while it was lower in Europe and including Russia, and North America (Heinitz et al. 2000). For example, Davies et al. (2001) reported the absence of *Salmonella* in fish from European Countries such as France, Great Britain, Greece and Portugal. However, Novotny et al., (2004), reported an outbreak of *Salmonella* blockley infections following smoked eel consumption in Germany. *Salmonella* paratyphi B infections were also reported associated with consumption of smoked halibut in Germany (Da Silva, 2002). Besides, consumption of dried anchovy was found to be the cause of *Salmonella* infection (Ling et al., 2002).

Table 1 shows the incidence of salmonellosis associated with all food vehicles, and with separately seafood, for the European Union in 2007 (FAO,2010).


Table 1. Fishery product associated outbreaks in the European Union, 2007 (Data from FAO,2010)

*Salmonella* has also been detected in US market oysters and in other US imported seafood from different countries (Heinitz et al. 2000; Ponce et al., 2008). For the 9-year period 1990– 1999, the FDA in the United States examined imported and domestic sh and seafoods for *Salmonella*. Of the 11.312 imported samples, 7.2% were positive while only 1.3% of the 768 domestic samples were positive.

The most common serovar found in the world was *S. Weltvreden* (Heinitz et al. 2000; Jay et al., 2005). In seafood the commonest serotype encountered was S. Worthington followed by S. Weltevreden. The diversity of serovars associated with fish and fishery product was highest in Southeast Asia and next highest in South America (FAO, 2010). Most *Salmonella* contamination problems in fishery product associated with shrimp. Almost one-quarter of all detentions, and more than half of the violations for *Salmonella*, were for shrimp and prawns (farm raised and wild caught).

of raw or insufficiently heat treated fish and cross-contamination during processing and about 12% of the foodborne outbreaks related to consumption of fish are caused by bacteria including *Salmonella* (Huss et al., 2000; Aberoumand, 2010). Similarly, The U.S. Food and Drug Administration's (FDA) data showed that *Salmonella* was the most common contaminant of fish and fishery products (Allshouse et al., 2004). Up to 10-15% of fish samples from India and Mexico were positive of *Salmonella* which has also been detected in several crustacean and molluscan products from India and Malaysia (Huss & Gram 2003). *Salmonella* contamination in fish and fishery products has also been reported from other countries like Thailand, Hong Kong, Spain and Turkey (Herrera et al., 2006; Kumar et al., 2009; Pamuk et al, 2011). The highest *Salmonella* incidence in fishery products was determined in Central Pacific and African countries while it was lower in Europe and including Russia, and North America (Heinitz et al. 2000). For example, Davies et al. (2001) reported the absence of *Salmonella* in fish from European Countries such as France, Great Britain, Greece and Portugal. However, Novotny et al., (2004), reported an outbreak of *Salmonella* blockley infections following smoked eel consumption in Germany. *Salmonella* paratyphi B infections were also reported associated with consumption of smoked halibut in Germany (Da Silva, 2002). Besides, consumption of dried anchovy was found to be the cause

Table 1 shows the incidence of salmonellosis associated with all food vehicles, and with

products 130 3 2.3

All food vehicles 2025 590 29.1 Table 1. Fishery product associated outbreaks in the European Union, 2007 (Data from

*Salmonella* has also been detected in US market oysters and in other US imported seafood from different countries (Heinitz et al. 2000; Ponce et al., 2008). For the 9-year period 1990– 1999, the FDA in the United States examined imported and domestic sh and seafoods for *Salmonella*. Of the 11.312 imported samples, 7.2% were positive while only 1.3% of the 768

The most common serovar found in the world was *S. Weltvreden* (Heinitz et al. 2000; Jay et al., 2005). In seafood the commonest serotype encountered was S. Worthington followed by S. Weltevreden. The diversity of serovars associated with fish and fishery product was highest in Southeast Asia and next highest in South America (FAO, 2010). Most *Salmonella* contamination problems in fishery product associated with shrimp. Almost one-quarter of all detentions, and more than half of the violations for *Salmonella*, were for shrimp and

**Number of**  *Salmonella* **outbreaks** 

75 2 2.7

**% of outbreaks associated with**  *Salmonella*

of *Salmonella* infection (Ling et al., 2002).

Fish and fishery

Crustaceans, shellfish, molluscs, and products

FAO,2010)

domestic samples were positive.

prawns (farm raised and wild caught).

**Food vehicle Number of** 

separately seafood, for the European Union in 2007 (FAO,2010).

**outbreaks** 


Salmonella in Fish and Fishery Products 97

*S*. Newington + *S*. Newport + + + + +

*S*. Oranienburg + + + +

*S*. Panama +

*S*. Phoneix +

*S*. Saintpaul + + + + + + *S*. Saka + +

**Eastern Caribbean Europe and Russia Mexico Middle East** 

**North** 

**America/** 

**Multiple**

**South** 

**America** 

**Serotype India/ SE Asia Africa Central America Central pacific**

*S*. Newbrunswick +

*S*. Ohio + +

*S*. Pomana + + *S*. Poona + + +

*S*. Rubislaw + + +

*S*. Saphra +

*S*. Senftenberg + + + + +

*Salmonella*

*S*. Nchanga +

*S*. Othmarschen +

*S*. Paratyphi B Java + *S*. Parera +

*S*. Potsdam +

*S*. Reading + *S*. Redba + *S*. Reinikendorf + *S*. Riggil + *S*. Rissen +

*S*. Sandiego +

*S*. Sarajane + *S*. Schleisshein +

*S*. Singapore + *S*. Srinagar +

*S*. Takoradi +

*S*. Schwarzengrun

*S*. Onireke +

*S*. Orientalis + *S*. Oslo + +

*S*. Paratyphi B + +

*S*. Pullorum +

*S*. Stanley + +


*S*. Heidelber + + +

*S*. Houten + + +

*S*. Javiana + + + *S*. Kentucky + + + +

*S*. Litchfield +

*S*. Marina +

*S*. Mendoza +

*S*. Mosselbay +

*S*. Nairobi + +

**Eastern Caribbean Europe and Russia Mexico Middle East** 

**North** 

**America/** 

**Multiple**

**South** 

**America** 

**Serotype India/ SE Asia Africa Central America Central pacific**

*S*. Hilversum +

*S*. Infantis + + +

*S*. Lanka + +

*S*. Liandoff +

*S*. Meleagridis + +

*S*. Michigan + *S*. Minnesota + +

*S*. Muenchen + +

*S*. Muenster + +

*Salmonella*

*S*. Houten + *S*. Hull + *S*. Hvittingfoss + *S*. Idikan +

*S*. Irumu + *S*. Isangi +

*S*. Kirkee + *S*. Kottbus + *S*. Krefeld + *S*. Kumasi +

*S*. Lansing + *S*. Lexington +

*S*. Lindenburg +

*S*. Liverpool +

*S*. Mgutani + *S*. Miami +

*S*. Montevideo + *S*. Morehead +

*S*. London + + *S*. Manila +

*S*. Mbandaka + +


Salmonella in Fish and Fishery Products 99

*Salmonella* sp. can multiply and survive in the estuarine environments and tropical freshwater environments for weeks although open marine waters are free from *Salmonella* (Huss,1994; Huss & Gram 2003). *Salmonella* prefers to grow at 37°C. Compared to other Gram-negative bacteria, *Salmonella* are relatively resistant to various environmental factors. They grow at temperatures between 5°C and 47°C. There are reports that they survive for longer than *E. coli* in sea and freshwater environments (Huss, 1994; Sugumar & Mariappan, 2003; Marriot & Gravani, 2006). *Salmonella* have been also reported to be able to grow within the temperature range of 2-54°C, although growth below 7°C has largely been observed only in microbiological culture media and growth above 48°C is confined to mutants or tempered strains (Bremer et al. 2003). A few *Salmonella* serotypes can grow over a pH range of 3.6–9.6, which is mildly basic to strongly acidic. Optimum growth occurs at a pH of 6.5–7.5, which is close to neutral. Other factors such as temperature, the type of acid present and the presence of antimicrobials can effect the minimum pH for growth (Brands, 2006; Marriot & Gravani, 2006; Lawley et al., 2008). It requires a minimum Aw of 0.94 (and possibly 0.93) with a maximum salt content of 4.0% to 5.0% (Huss, 1994; Lawley et al., 2008). A study by Basti et al., (2006), for example, showed complete elimination of *Salmonella* on heavy salted fish and heavy salted cold smoked fish due to the high concentration levels of NaCl (>7%). Limiting

**5. Survival and growth parameters** 

conditions were summarized for *Salmonella* in Table 3.

Table 3. Limiting Conditions for *Salmonella* Growth

but not eliminate *Salmonella* in products of aquaculture.

the contamination of aquaculture products with *Salmonella*.

Farm design and layout should be such that prevents cross contamination

**aquaculture products according to FAO (2011)** 

**Farm layout, equipment and design** 

min. pH

**6. Control of** *Salmonella* **in fish and fishery products** 

max. pH

Since most of fish products, with the exception of coldsmoked fish, sushi, and a few specialty products such as spiced, salted, or pickled fish, are expected to be cooked prior to consumption, the presence of microbiological pathogens should not present a human health

The aquaculture farm is the first link in the food safety continuum and controls must be in place and implemented throughout the food safety chain. The experts agreed that good hygienic practices during aquaculture production and biosecurity measures can minimize

**Some important control measures to minimize the risk of** *Salmonella* **contamination of** 

Farms should be secured from the entry of wild and domestic animals that may lead to

max.% water phase salt

0.94 3.7 9.5 5 5 C 47 C facultative

min. temp

max. temp

Oxygen requirement

anaerobe

Pathogen min. Aw

hazard (Flick, 2008).

**Farm location** 

*Salmonell a* spp.

(using salt)


Table 2. *Salmonella* serotype reported in fish and fishery products (Data from FAO, 2010)

Fig. 1. Share of FDA violations for *Salmonella*, by fishery product, 2001 (data from Allshouse et al., 2004).

**Eastern Caribbean Europe and Russia Mexico Middle East** 

**North** 

**America/** 

**Multiple**

**South** 

**America** 

**Serotype India/ SE Asia Africa Central America Central pacific**

*S*. Uganda +

*S*. Tennessee + +

*S*. Thompson + + + +

*S*. Virchow + + +

*S*. Tornow + +

*S*. Typhimurium + + + + + +

*S*. Weltevreden + + + + + +

Table 2. *Salmonella* serotype reported in fish and fishery products (Data from FAO, 2010)

Fig. 1. Share of FDA violations for *Salmonella*, by fishery product, 2001 (data from Allshouse

*Salmonella*

*S*. Tananarive +

*S*. Typhi +

*S*. Urbana +

*S*. Wandsworth + *S*. Washington +

*S*. Weston + *S*. Worthington +

et al., 2004).

*S*. Telelkebir +
