Raw milk kills pathogens in milk

The healthy human body lives in symbiotic relationship with microorganisms.

The following tests revealed that raw milk reduces pathogenic bacteria in or added to the milk:

Raw Milk Challenge Test I

Large amounts of Campylobacter (an amount found in 20,000 grams manure) added to chilled raw milk (4°C):

Most strains showed a dramatic decline

Day 0 = 13,000,000/ml

Day 9 = less than 10/ml

The only stain that did not decline was a non-human strain.

Applied and Environmental Microbiology, 1982;44(5):1154-58

Raw Milk Challenge Test II

Campylobacter in raw milk at body temperature (37°C):

Bovine strains decreased by 100 cells/ml in 48 hrs.

Poultry strains decreased by 10,000 cells/ml in 48 hrs.

The protective components worked more quickly to reduce levels of pathogens in warm milk than in chilled milk.

Mikrobiyolji Bul ,1987:21(3):200-5

Raw Milk Challenge Test III

Lactoperoxidase in raw milk kills added fungal and bacterial agents^1,2

Raw goat milk kills Campylobacter jejuni in a challenge test ³

1. Life Sciences, 2000;66(25):2433-9.

2. Indian J Experimental Biology, 1998;36:808-10.

3. J. Food Protection,63: 916-920.

Raw Milk Challenge Test IV

Seven strains of E. coli O157:H7 in amounts of 1 million/ml added to raw milk. The pathogen failed to grow and died off gradually.¹

L. mono added to raw milk at 98.6°F. After 56 hours, no viable cells of L. mono were detectible.2

"The growth of Staph. Aureus, S. Enteritidis and L. monocytogenes in raw milk at 99°C was reduced markedly compared to the growth of these organisms in pasteurized milk."3

Five strains of E. coli O157:H7 did not grow at 41o F and decreased over days.4

Raw Milk Challenge Test V

BSK Food & Dairy Laboratories (2002) inoculated raw colostrum and raw milk samples at 40°F from Organic Pastures Dairy (Fresno, California) with a cocktail containing 2.4 million Salmonella, 9.2 million E. coli O157:H7 and 8.1 million Listeria monocytogenes (these huge amounts are a very unlikely occurrence in a real-life situation).

Yet even with these huge amounts, pathogen counts declined over time and in some cases were undetectable within a week.

E.coli O157:H7 did increase slightly after a seven-days decline, possibly due to exhaustion of anti-microbial components in the milk.

The laboratory concluded: "Raw colostrum and raw milk do not appear to support the growth of Salmonella, E. coli O157:H7 or Listeria monocytogenes."

McAffee, M. Unpublished data.

Coliforms in raw milk inhibit pathogen growth

Coliform bacteria ferment lactose into lactic-acid.   Coliforms are not necessarily pathogens

With few exceptions, coliforms are not considered to be a health risk.  ". . . these rod-shaped bacteria are found everywhere in the environment, including the gut, the feces, soil, water and plants. However, " . . . they can be considered normal inhabitants of many soil and water environments that have not been impacted by fecal pollution"

". . . Research results have shown that total coliforms may not be an appropriate bacterial indicator of fecal pollution."

". . . Significant concentrations of coliforms in distribution systems do not represent a health risk to water consumers."

Stevens and others. Review of Coliforms, Australian Government, 10-11 April 2003

Four main groups: E.coli, Kiebsiella, Enterobacter, Citrobacter.

-   Enterococci (considered "virulent" and/or "antibiotic resistant" in hospitals) inhibit pathogens such as Listeria in raw feta cheese.

eurekalert.org, April, 2008.

-   Lactobacillus and staphylococcus produce bacteriocins against L. Monocytogenes and are sold as commercial starters to control listeria.

Hull. Australian Journal of Dairy Technology Aug 2007;62(2):100-102

-   Staphylococci , Streptococci , Lactobacillis and Ent. faecalis in raw human milk inhibit pathogenic Staph aureus .

Heikkila and Saris. J Appl Microbiology 2003,95, 471-478