Human enteric pathogens

Brandi, M. T. (2006). Fitness of human enteric pathogens on plants and implications for food safety (1). Annu. Rev. Phytopathol. 44,367-392. 

Enteric pathogen infection in poultry and transfer risk to the human food chain... 

A Lactobacillus strain was recently shown to inhibit competitively adhesion of enteropathogenic E. coli to pig ileum and interfered with bacterial attachment to the mucosal layer of ileal conducts (Blomberg et al., 1993). Although L. acidophilus inhibits the adhesion of several enteric pathogens to human intestinal cells in culture, when pathogen attachment preceded L. acidophilus treatment, no inhibitory interference occurred indicating that steric hindrance of site occupation is important in the inhibition of adhesion. Thus, therapeutic use is likely to be limited to preventive application of probiotics. 

Human infections with Salmonella spp. and E. coli 0157 H7 are a common worldwide phenomenon. Livestock may serve as a source of several relevant human pathogenic microorganisms (Table 19.2). The most prevalent group is the enteric pathogens which include bacteria, viruses and parasites (i.e. protozoa and helminths). Animals may shed pathogens through excreta without... 

Guan T Y and Holley R A (2003), Pathogen survival in swine manure environments and transmission of human enteric illness A review , Journal of Environmental Quality, 32 (2), 383-391. 

Newburg, D. S., Ruiz-Palacios, G. M., and Morrow, A. L. (2005). Human milk glycans protect infants against enteric pathogens. Annu. Rev. Nutr. 25, 37-58. 

Escherichia coli is a member of the bacterial family, Enterobacteriaceae, the enteric bacteria. Members of the Enterobacteriaceae are among the most important bacteria medically. A number of genera within the family are human intestinal pathogens (e.g., Salmonella, Shigella, Yersinia). Several others are normal colonists of the human gastrointestinal tract (e.g., Escherichia, Enterobacter, Klebsiella), but these bacteria, as well, may occasionally be associated with diseases of humans. E. coli is a facultative anaerobic, motile, gram-negative rod. 

A number of reviews and studies have been published dealing with the potential health and nutritional benefits of EPSs from LAB in fermented dairy products for example, EPSs from LAB have been associated with various health benefits, such as the lowering of cholesterol (Liu et al., 2006 Maeda, Zhu, Omura, Suzuki, Kitamura, 2004 Nakajima, Suzuki, Hirota, 1992), anti-hypertensive effects (Maeda, Zhu, Suzuki, Suzuki, Kitamura, 2004), anticarcinogenic effects (Furukawa, Takahashi, Yamanaka, 1996 Kitazawa et al., 1991) and immunomodulatory activity (Chabot et al., 2001 Nishimura-Uemura et al., 2003 Vinderola, Matar, Palacios, Perdigon, 2007). Apart from these effects, there also appears be a complex web of interactions between LAB EPSs and human gut microbiota, some enteric pathogens and toxins, and gut epithelial cells and the immune system the discussion that follows presents evidence for health and nutritional benefits that are potentially derived from these relationships. 

Savkovic, S. D., Koutsouris, A., and Hecht, G. (1996). Attachment of a noninvasive enteric pathogen, enteropathogenic Escherichia coli, to cultured human intestinal epithelial monolayers induces transmigration of neutrophils. Infect. Immun. 64, 4480-4487. 

Lactic acid bacteria based fermented products have a long reputation for being positively beneficial to humans, particularly linked with fermented milk such as nutritional improvement of foods, inhibition of enteric pathogens, hypocholestaemic action, anticancer activity, and stimulation of the immune system (Adams and Moss 1995). Similarly, phenolic phytochemicals have potential for regulation and chemopre-vention of oxidative and infectious diseases (Shetty 1999). 

Viruses are the 2nd most problematic pathogen, behind protozoa. As with protozoa, most waterborne viral diseases don t present a lethal hazard to a healthy adult. Waterborne pathogenic viruses range in size from 0.020-0.030 jtim, and are too small to be filtered out by a mechanical filter. All waterborne enteric viruses affecting humans occur solely in humans, thus animal waste doesn t present much of a viral threat. At the present viruses don t present a major hazard to people drinking surface water in the U.S., but this could change in a survival situation as the level of human sanitation is reduced. Viruses do tend to show up even in remote areas, so a case can be made for eliminating them now. 

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