of the product (Raghunath et al. 1997). With increasing environmental pollution, a
heavy metal exposure assessment study is necessary (Ikeda et al. 1996, Raghunath
et al. 1997)
3.2.2 Microbiological Contaminants
The presence of foodborne pathogens in milk and milk products is due to direct
contact with contaminated sources in the dairy farm environment, infected animals,
and improper personnel hygiene (Zeinhom and Abdel-Latef 2014). The microbiological quality of milk and dairy products is influenced by the initial flora of raw
milk, the processing conditions, and post-heat treatment contamination (Rajagopal
et al. 2005). Today’s context, food spoilage is a big economic problem worldwide.
Undesirable microbes in the milk can cause spoilage of dairy products which include
Gram-negative psychrotrophs, coliforms, lactic acid bacteria, yeasts, and molds. In
addition, various bacteria of public health concern such as Salmonella spp.,
L. monocytogenes, C. jejuni, Y. enterocolitica, pathogenic strains of E. coli, and
enterotoxigenic strains of S. aureus may also be found in milk and dairy products. In
industrialized countries like India, the percentage of the population suffering from
foodborne diseases each year has been reported to be up to 30%. Though there are
various foodborne pathogens that have been identified for foodborne illness, Campylobacter, Salmonella, L. monocytogenes, and E. coli O157:H7 have been generally found to be responsible for the majority of foodborne outbreaks (Alocilja and
Stephen 2003; Chemburu et al. 2005). In the last two decades, other infectious
agents have been either newly defined or newly concomitant with foodborne transmission. L. monocytogenes, E. coli O157:H7, C. jejuni, Staphylococcus intermedia,
Enterobacter sakazakii, and Salmonella enteritidis are examples of newly described
pathogens that often are foodborne. The most dangerous among them are
enterohemorrhagic E. coli strains, especially serotype O157:H7. E. coli O157:H7
has become a pathogen of major concern in dairy industries, and to the public,
because of its ability to cause severe illness, in particular hemorrhagic colitis,
hemolytic uremic syndrome, and thrombotic thrombocytopenic purpura (Picozzi
et al. 2005 and Reuben et al. 2013). Foodborne salmonellosis has been recognized
due to consumption of raw or improperly pasteurized milk and milk products
(Karshima et al. 2013). Recently CDC has reported an incidence of
L. monocytogenes in pasteurized milk, Mexican cheeses, and pasteurized cheeses
(FDA 2010; CDC 2012/2013/2014; CDC NORS 2012), Salmonella braenderup
(OHA 2010) and Salmonella java in pasteurized cheddar cheese, Salmonella Montevideo in pasteurized shredded cheeses, Salmonella newport in pasteurized milk,
Salmonella typhimurium in pasteurized milk, Campylobacter jejuni in pasteurized
milk and cheese curd, and Staphylococcus aureus in powdered milk and pasteurized
cheese (CDC NORS 2012).
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99
heavy metal exposure assessment study is necessary (Ikeda et al. 1996, Raghunath
et al. 1997)
3.2.2 Microbiological Contaminants
The presence of foodborne pathogens in milk and milk products is due to direct
contact with contaminated sources in the dairy farm environment, infected animals,
and improper personnel hygiene (Zeinhom and Abdel-Latef 2014). The microbiological quality of milk and dairy products is influenced by the initial flora of raw
milk, the processing conditions, and post-heat treatment contamination (Rajagopal
et al. 2005). Today’s context, food spoilage is a big economic problem worldwide.
Undesirable microbes in the milk can cause spoilage of dairy products which include
Gram-negative psychrotrophs, coliforms, lactic acid bacteria, yeasts, and molds. In
addition, various bacteria of public health concern such as Salmonella spp.,
L. monocytogenes, C. jejuni, Y. enterocolitica, pathogenic strains of E. coli, and
enterotoxigenic strains of S. aureus may also be found in milk and dairy products. In
industrialized countries like India, the percentage of the population suffering from
foodborne diseases each year has been reported to be up to 30%. Though there are
various foodborne pathogens that have been identified for foodborne illness, Campylobacter, Salmonella, L. monocytogenes, and E. coli O157:H7 have been generally found to be responsible for the majority of foodborne outbreaks (Alocilja and
Stephen 2003; Chemburu et al. 2005). In the last two decades, other infectious
agents have been either newly defined or newly concomitant with foodborne transmission. L. monocytogenes, E. coli O157:H7, C. jejuni, Staphylococcus intermedia,
Enterobacter sakazakii, and Salmonella enteritidis are examples of newly described
pathogens that often are foodborne. The most dangerous among them are
enterohemorrhagic E. coli strains, especially serotype O157:H7. E. coli O157:H7
has become a pathogen of major concern in dairy industries, and to the public,
because of its ability to cause severe illness, in particular hemorrhagic colitis,
hemolytic uremic syndrome, and thrombotic thrombocytopenic purpura (Picozzi
et al. 2005 and Reuben et al. 2013). Foodborne salmonellosis has been recognized
due to consumption of raw or improperly pasteurized milk and milk products
(Karshima et al. 2013). Recently CDC has reported an incidence of
L. monocytogenes in pasteurized milk, Mexican cheeses, and pasteurized cheeses
(FDA 2010; CDC 2012/2013/2014; CDC NORS 2012), Salmonella braenderup
(OHA 2010) and Salmonella java in pasteurized cheddar cheese, Salmonella Montevideo in pasteurized shredded cheeses, Salmonella newport in pasteurized milk,
Salmonella typhimurium in pasteurized milk, Campylobacter jejuni in pasteurized
milk and cheese curd, and Staphylococcus aureus in powdered milk and pasteurized
cheese (CDC NORS 2012).
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99