286
contaminated coastal areas or ponds and fresh fish from these areas (Feldhusen
2000). Salmonella enteritidis, Salmonella paratyphi, and Salmonella typhimurium
are important species and are responsible for high mortality rates (Amagliani et al.
2012). Historically, sewage contamination of shellfish harvest beds led to large
shellfish-associated outbreaks of Salmonella serotype typhi infections (Iwamoto
et al. 2010). Salmonella enterica serovar Enteritidis and serovar Typhimurium are
the most common Salmonella that cause infection and death (Butt et al. 2004).
Salmonella isolation was reported in 133 bivalve samples harvested from a polluted shellfish growing area (Monfort et al. 1994). In a study that examined 100 fish
and shellfish samples, Salmonella was detected in 59% of shrimp samples and 30%
of oysters (Shabarinath et al. 2007). Martinez-Urtaza et al. (2003) reported the isolation of Salmonella serovars in live molluscs from the Galician region of Spain. In
Shrimp, oyster and mussel samples collected from different markets in Alexandria,
Egypt, Salmonella was determined as 14.0%, 8% and 4 8%, respectively (Bakr et al.
2011). In a study conducted on the presence of Salmonella enterica subsp. enterica
in different species of bivalve molluscs and seawater, it was reported that the presence of Salmonella enterica subsp. enterica in seawaters and in bivalve molluscs
varied by bivalve species and classification areas (Rubini et al. 2018). A study studied on the presence of Salmonella spp. in cockles and carpet shells collected from a
class B growing natural bed in Sardinia (Italy), the fact that no Salmonella has been
detected confirms this (Marceddu et al. 2017).
The most common factors contributing to salmonellosis outbreaks are improper
cooking, inadequate storage, cross-contamination and use of raw ingredients in the
preparation of seafood. Main post-harvest critical control points for Salmonella
control in seafood, irrespective of whether the primary source is a marine or an
aquaculture product, include: primary chilling immediately in an ice-water slurry
on vessels and at harvest site; in cooked products, applying time–temperature
regimes to give log reductions of contamination levels at sites of microbiological
concern; rapid chilling after cooking; plate freezing, followed by frozen storage
(Amagliani et al. 2012).
5.2.1.3 Escherichia coli
Escherichia coli has been reported to serve as a useful indicator of faecal pollution
due to its relationship with the digestive system of warm-blooded animals, and this
Gram-negative, rod-shaped, constitute to coliform population. Although E. coli is
not generally considered pathogenic, a few of pathogenic strains have been identified. Pathogenic types include enterotoxigenic, enteropathogenic, enteroinvasive,
and hemorrhagic strains. The first three are usually associated with human faecal
contamination, whereas the latter is most often associated with farm animals
(Soniat 2009).
The E. coli outbreak due to consumption of butterfly shrimp in sushi restaurants
in Nevada (USA), which is thought to be caused by poor food processing practices
and infected food processors, has been reported (Jain et al. 2008).
5 Shellfish Safety
contaminated coastal areas or ponds and fresh fish from these areas (Feldhusen
2000). Salmonella enteritidis, Salmonella paratyphi, and Salmonella typhimurium
are important species and are responsible for high mortality rates (Amagliani et al.
2012). Historically, sewage contamination of shellfish harvest beds led to large
shellfish-associated outbreaks of Salmonella serotype typhi infections (Iwamoto
et al. 2010). Salmonella enterica serovar Enteritidis and serovar Typhimurium are
the most common Salmonella that cause infection and death (Butt et al. 2004).
Salmonella isolation was reported in 133 bivalve samples harvested from a polluted shellfish growing area (Monfort et al. 1994). In a study that examined 100 fish
and shellfish samples, Salmonella was detected in 59% of shrimp samples and 30%
of oysters (Shabarinath et al. 2007). Martinez-Urtaza et al. (2003) reported the isolation of Salmonella serovars in live molluscs from the Galician region of Spain. In
Shrimp, oyster and mussel samples collected from different markets in Alexandria,
Egypt, Salmonella was determined as 14.0%, 8% and 4 8%, respectively (Bakr et al.
2011). In a study conducted on the presence of Salmonella enterica subsp. enterica
in different species of bivalve molluscs and seawater, it was reported that the presence of Salmonella enterica subsp. enterica in seawaters and in bivalve molluscs
varied by bivalve species and classification areas (Rubini et al. 2018). A study studied on the presence of Salmonella spp. in cockles and carpet shells collected from a
class B growing natural bed in Sardinia (Italy), the fact that no Salmonella has been
detected confirms this (Marceddu et al. 2017).
The most common factors contributing to salmonellosis outbreaks are improper
cooking, inadequate storage, cross-contamination and use of raw ingredients in the
preparation of seafood. Main post-harvest critical control points for Salmonella
control in seafood, irrespective of whether the primary source is a marine or an
aquaculture product, include: primary chilling immediately in an ice-water slurry
on vessels and at harvest site; in cooked products, applying time–temperature
regimes to give log reductions of contamination levels at sites of microbiological
concern; rapid chilling after cooking; plate freezing, followed by frozen storage
(Amagliani et al. 2012).
5.2.1.3 Escherichia coli
Escherichia coli has been reported to serve as a useful indicator of faecal pollution
due to its relationship with the digestive system of warm-blooded animals, and this
Gram-negative, rod-shaped, constitute to coliform population. Although E. coli is
not generally considered pathogenic, a few of pathogenic strains have been identified. Pathogenic types include enterotoxigenic, enteropathogenic, enteroinvasive,
and hemorrhagic strains. The first three are usually associated with human faecal
contamination, whereas the latter is most often associated with farm animals
(Soniat 2009).
The E. coli outbreak due to consumption of butterfly shrimp in sushi restaurants
in Nevada (USA), which is thought to be caused by poor food processing practices
and infected food processors, has been reported (Jain et al. 2008).
5 Shellfish Safety