Microbial Contamination of Foods

Microbial Contamination of Foods

• Air: Spores from Bacillus spp., Clostridium spp., and molds are common air contaminants.
• Reduce airborne contamination by:
  • Removing potential sources.
  • Controlling dust using filtered air, positive air pressure, and reduced humidity.
• Soil: Contains multiple varieties of microorganisms, including molds, yeasts, and bacteria such as Enterobacter, Pseudomonas, Proteus, Micrococcus, Enterococcus, Bacillus.
• Fecal matter in soil: A common source of enteric pathogenic bacteria.
• Sediments: Where fish and seafood are harvested, can be a source of microorganisms.
• Sewage: Used as fertilizer, can contaminate food with enteropathogenic bacteria and viruses, a major concern for organically grown foods and imported produce.
• Prevention of soil and sewage contamination: Avoid using sewage as fertilizer, or use it only after efficient treatment to kill pathogens.
• Water: Used in food production, processing, storage, irrigation, drinking by animals, raising fish and seafood, washing foods, and cleaning equipment.
• Potable water: Should be used for processing, washing, sanitation, and as an ingredient in foods.
• Untreated water: Can contain pathogens and spoilage microorganisms.
• People: Foods come into contact with many people during production, handling, and consumption.
• Human Sources of Foodborne Pathogens: Pathogenic Escherichia coli, Campylobacter jejuni, Yersinia enterocolitica, Listeria monocytogenes.
• Animals: Laying birds can carry Salmonella enteritidis, and poor husbandry can lead to fecal contamination of animal surfaces (skin, hair, feathers, udder).
• Milk: Can be contaminated with fecal materials on the udder surface.
• Eggs: Can be contaminated with fecal material on the shell.
• Meat: Can be contaminated with intestinal contents during slaughtering.
• Enteric Pathogens from Fecal Materials: Salmonella spp., Pathogenic E. coli, Shigellae, Enteric viruses, Protozoa, and Helminths.
• Other Common Foodborne Organisms: Staphylococcus aureus, Micrococcus spp, molds, and yeasts.
• Prevention of Animal/Bird Contamination: Effective husbandry practices, testing animals for pathogens, culling carriers, using high-quality water, proper sanitation, and cleaning of animal surfaces.
• Milk Prevention: Proper cleaning of the udder before milking and immediate cooling of the milk.
• Fish and Seafood Prevention: Harvesting from non-polluted waters.
• Air: Microorganisms are present in dust, but do not grow in it.
• Air Contamination Factors: Humidity, dust particle size, temperature, air velocity, and microorganisms' resistance to drying.
• Human Sources: Dirty clothing, hair, and lack of personal hygiene can contribute to microbial contamination.
• Human Pathogens: Staphylococcus aureus, Salmonella spp, Shigella spp, Pathogenic E. coli, and hepatitis A.
• Food Ingredients: Many ingredients and additives can introduce spoilage and pathogenic microorganisms into food.
• High Microbial Load Ingredients: Spices, starch, sugar, and flour.
• Prevention of Ingredient Contamination: Sanitary production, antimicrobial treatments, and setting microbial specifications.
• Food Equipment: Can be a source of contamination from air, raw foods, water, and personnel.
• Equipment Contamination: Microorganisms can multiply rapidly on equipment.
• Equipment Cleaning: Thorough cleaning and sanitizing of equipment at regular intervals is crucial to prevent contamination.
• Packaging Materials: Must meet proper microbiological standards since they are used with ready-to-consume food.
• Equipment-Related Pathogens: Salmonella, Listeria, Escherichia, Enterococcus, Micrococcus, Pseudomonas, Lactobacillus, Listeria, yeasts, and molds.