The Types of Pathogenic Bacteria in Milk
- Raw milk can contain pathogenic bacteria.Milk, milk and hands image by Mykola Velychko from Fotolia.com
Pathogenic bacteria cause infectious diseases and can be found in milk and products made from milk, including ice cream and cheese. The characteristics of these bacteria vary between pathogens and so do the effects of the illnesses that they cause; some infections, if not treated correctly, can be deadly. - Listeria monocytogenes is a gram-positive organism that lives inside the intestines of 1 to 10 percent of humans. This bacterium resists the harmful effects of drying, heat and freezing incredibly well for a non-spore forming organism. It has been found in 37 different species of mammals and 17 different species of birds. Listeriosis manifestations include meningitis, encephalitis, septicemia and cervical or intrauterine infections in pregnant women that may cause a miscarriage. Upon the onset of this infection, flu-like symptoms occur along with a persistent fever; other symptoms include vomiting, diarrhea and nausea. This organism is able to grow in temperatures as low as three degree Celsius; this allows multiplication in foods that are refrigerated. This organism has been associated with raw milk, cheeses, ice cream, raw and cooked poultry, raw vegetables, raw and smoked fish and all types of raw meats.
- Yersinia enterocolitica is a gram-negative organism that is usually isolated from wounds, mesenteric lymph nodes, sputum and feces; it is one of the three pathogenic species within the Yersinia genus and causes gastroenteritis. Symptoms of infection usually begin within 24 to 48 hours of ingestion and include gastroenteritis with vomiting and/or diarrhea, abdominal pain and fever. These infections are similar to the symptoms of appendicitis but can also infect other areas such as the urinary tract, wounds and joints. Strains of this bacterium can be found in raw milk, oysters, fish and meats. Infection does not occur frequently, but is more prevalent in Scandinavia, Japan and Northern Europe; it has been misdiagnosed as appendicitis and Crohn's disease.
- Campylobacter jejuni is a gram-negative form of bacteria that has a requirement for small levels of oxygen and is sensitive to stresses of the environment. This organism requires 2 to 10 percent of carbon dioxide and 3 to 5 percent oxygen for its growth conditions to be at the optimum level. This organism is the lead cause in the United States of bacterial diarrhea and causes more diseases than the combination of salmonella and shigella. Some of the major symptoms that occur from ingesting this organism other than diarrhea are abdominal pain, headache, muscle pain, nausea and fever. The illness usually lasts for approximately seven to 10 days; erythromycin reduces the amount of time that the bacteria are shed in the infected person's feces. Raw milk, non-chlorinated water and raw chicken are sources of infection.
