Nurmi concept

Pivnick, H. and Nurmi, E. 1982. The Nurmi concept and its role in the control of Salmonella in poultry. In Developments in Food Microbiology (R. Davis, ed.), Vol. 1, p. 41. Applied Science, Barking, England. 

The competitive exclusion concept was originated by Nurmi and Rantala (1973), based on the study of Salmonella in chickens. Newly hatched birds in modern hatcheries are not able to obtain the normal gut flora of adult birds. As a result, the intestines of chicks can be easily colonized by foodbome pathogens when present. When the chickens were inoculated immediately after birth with the intestinal content of a Salmonella-free adult bird, the frequency of Salmonella infections was radically reduced and the number of Salmonella needed to colonize the ceca of chicks increased. Hence, the normal gastrointestinal microflora of adult chickens can competitively exclude Salmonella from colonizing the naive intestinal tract of chicks. 

After establishment of the basic concept of competitive exclusion, considerable research has been done to identify the mechanisms by which bacteria are competitively excluded from host sites (Nurmi et al. 1992 Zhao et al. 1995). Responsible factors include competition for receptor sites on the intestinal epithelium, production of volatile fatty acids and/or other antibacterial substances, and competition among different bacteria for limited nutrients. The use of LAB as a probiotic for live poultry and livestock has been extensively studied and has... 

Nurmi E, Nuotio L, Schneitz C (1992) The competitive exclusion concept development and future. Int J Food Microbiol 15 237-240 Okereke A, Montville TJ (1991) Bacteriocin-mediated inhibition of Clostridium botulinum spores by lactic acid bacteria at refrigeration and abuse temperatures. Appl Environ Microbiol 57 3423-3428 Ouwehand AC, Sondberg Svendsen L, Leyer G (2011) Probiotics from strain to product. In Kniebel W, Salminen S (eds) Probiotics and health claims. Wiley, W. Sussex, pp 37-47... 

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