**2.4** *Salmonella* **in milk**

334 Salmonella – A Dangerous Foodborne Pathogen

Most *Salmonella* can survive for extended periods in food stored at refrigeration to ambient room temperatures (2-25°C). Some *Salmonella* strains can grow in high temperature as 54°C (Montville & Matthews, 2008). The *Salmonellla* are generally transmitted to humans through consumption of contaminated food of animal origin, mainly meat, poultry, eggs and milk. The prevalence of pathogenic serotypes associated with food-borne disease varies by geographical location (Watie & Yousef, 2010). The *Enteritidis*, *Typhimurium*, *Newport* and *Javiana* were the most prevalence serotypes in the United States in 2007. The symptoms and sign of *Salmonella* infection include diarrhea, abdominal pains, nausea, vomiting and chills,

In eggs, various *Salmonella* serovars can be found in the egg content, principally *S. enteritidis*, is the serovar most frequently with egg infection (Gast & Beard, 1990; Humphrey et al., 1991; de Louvois 1993). A few reported in human on outbreaks of *Salmonella* food poisoning related egg caused by *S. typhimurium* (EFSA, 2010a)*.* Other *Salmonella* serovars, e.g., *S. mbandaka*, *S. livingstone*, *S. heidelberg*, *S. hadar*, *S. infantis* and *S. virchow*, also occur with low frequency in layers and consequently on egg surfaces (Chemaly et al., 2009). The risk assessment estimates the probability of human illness due to *Salmonella* following the ingestion of a single food serving of internally contaminated shell eggs, either consumed as whole eggs, egg meals, or product containing these ingredients such as cake or mayonnaise. The growth of *Salmonella* in egg albumen is eased at 20°C, while it is unable to grow at temperature less than 10°C (Gantois et al., 2009). Recently, an average prevalence of 0.5% eggs contaminated with *Salmonella* was reported across the member states of the European

Pork and pork products are also recognized as one of the major sources of human *Salmonella* food poisoning. The commonly isolated non-typhoid *Salmonella* serovars in pigs, pork and humans is *S. typhimurium* (Astorga Marquez et al., 2007; Boyen et al., 2008; Perugini et al., 2010). During further processing of meat, such as cutting and mincing, *S. typhimurium* from contaminated pork cuts may then spread into pork preparations (Gonzales-Barron et al., 2010). The proportion of human *Salmonella* food poisoning attributable to pork has been estimated to be between 9 and 15% in Denmark and around 21% in Netherlands (EFSA, 2008; Hald et al., 2004). In Ireland, the pork meat has been identified as a significant source of *Salmonella* with an incidence of 2.9% as surveyed in processing plants (Gonzales-Barron, 2010b). A Belgian survey from 2000 to 2003 indicated that the mean prevalence values of S*almonell*a in 25 g samples of pork meat cuts and minced meat were 17.3% (95% CI: 15.0–

In the European Union, three of the top four serovars (*S. infantis*: 29.2%, *S. enteritidis*: 13.6%, *S. kentucky*: 6.2% and *S. typhimurium*: 4.4%, respectively) isolated from poultry are also found in the top four serovars (*S. enteritidis*: 58.0%, *S. typhimurium*: 21.9%, *S. infantis*: 1.1%

19.7%) and 11.1% (95% CI: 9.4–13.0%) (Ghafir et al., 2007, 2005), respectively.

**2. Prevalence of** *Salmonella* **in foods** 

**2.1** *Salmonella* **in egg** 

Commission (EFSA, 2010b).

**2.2** *Salmonella* **in meat** 

**2.3** *Salmonella* **in poultry** 

leading to dehydration and headaches (Richard et al., 2008).

One route of *Salmonella* transmission is via raw/unpasteurized milk and products made from raw milk (e.g. cheese) (Cody 1999). In a 2000 study of New York dairy herds, *Salmonella* were isolated from 1.5 percent of 404 milk filters. *Salmonella* contamination of bulk milk most likely occurs through fecal contamination, and mitigation through improved hygiene practices may be possible (Karns et al., 2005). Consumption of cheese contaminated with the mentioned pathogens can lead to serious health problems, which the outbreaks of *Salmonella* spp. in Mozzarella cheese can be seen since 1981 in Italy and USA (De Buyser et al., 2001). In 1985, D'Aoust et al. found that *S. typhimurium* was linked to Canadian foodborne outbreaks associated with the consumption of Cheddar cheese.
