This document discusses the microbial flora commonly found in meat and meat products. It begins by introducing that meat is easily contaminated during slaughter and processing, providing nutrients for microbial growth. There are three main types of microorganisms that can be present: pathogenic bacteria like Salmonella and E. coli that can cause foodborne illness; spoilage bacteria such as Pseudomonas and Brochothrix thermosphacta that lead to off-odors and discoloration; and molds like Aspergillus and Penicillium that can produce mycotoxins harmful to animal and human health. The document emphasizes that contaminated meat is a major source of foodborne disease and discusses some of the most frequent pathogens involved in meat

1. MICROBIAL FLORA OF
MEAT AND MEAT
PRODUCTS
PRESENTED BY:
Rashok Khanal
B.V.Sc&AH
8th Semester
Roll No - 36
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2. Meat Diet for UsApril 10, 2020 2

3. Table Of Contents
Introduction
Bacteria Generally Found In Meat
1. Pathogenic Organisms
2. Spoilage microorganisms
3. Molds
References
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4. Introduction
• They are the microbiological organisms causing food borne diseases
to the consumers and are mostly Bacteria or their metabolites,
Parasites, Virus and Toxins.
• They are caused in different countries due to the contaminated foods
consumed, food processing, its preparation, handling, storage
techniques employed, and sensitivity of the population.
• Contaminated raw meat is the major sources of food borne disease as
during the slaughtering and processing, all potentially edible tissues
are subjected to contamination from a variety of sources within and
outside animal.
• Meat is easily spoiled by microorganism because it contains a lots of
nutrients, growth factor, etc and the ph is range from 5.2 to 7.0
which is mostly favourable for the growth of microorganisms.
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5. • Processed meat foods are more prone to contamination with
pathogenic microorganisms during the various stages of processing.
• Large quantities of bacteria were also present in fresh meat, imported
frozen meat, minced meat and liver
• Meat and meat products can serve as vehicles of many pathogenic
organisms. Several pathogens such as Bacillus cereus, Campylobacter
jejuni, Clostridium botulinum, Clostridium perfringens, Escherichia
coli, Listeria monocytogenese, Salmonella, Staphylococcus aureus and
Yersinia enterocolitica are known to produce serious foodborne
diseases among the consumers
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6. Spoiled Meat Salmonella in Meat
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7. Bacteria Generally Found In Meat
There are mainly three types of organisms generally found in Meat
1. Pathogenic organisms
eg : Brucella, Salmonella, Streptococcus, Mycobacterium
tuberculosis, Clostridium species
2. Spoilage microorganisms
eg: Achromobacter, Pseudomonas, Bacillus and Staphylococcus
3. Molds
eg: Aspergillus, Mucor, Penicillium
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8. Pathogenic Organisms
• The growth of microbes in meat is governed by a number of intrinsic and
extrinsic factors. Intrinsic properties of meat, such as pH and moisture can
promote microbial growth, whereas temperature is an extrinsic factor.
• The most frequent outbreaks associated with consumption of contaminated
meat are caused by Salmonella spp, L.monocytogenes and Y. enterocolitica
• The pathogens of concern in fresh and frozen meat and meat products includes
Salmonella spps, Escherichia coli and other enterohaemorrhagic E.coli, Listeria
monocytogenes, Staphylococcus aureus, Yersinia enterocolitica,
Camphylobacter spp, Clostridium perfringens and potential for Cl.botulinium
in cured hams and sausages.
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9. • In Nepal, Meat and meat products are highly preferred now a days so
the important sources of human infections with a variety of food-borne
pathogens,i.e. Salmonella spp, Camphylobacter jejuni,Camphylobacter
coli, Yersinia enterocolitica,verotoxigenic Escherichia coli and, to
some extent, Listeria monocytogenes has increased.
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10. Beef Products Due To Possible E.
coli O157:H7 Contamination
S.aureus in Meat
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11. Spoilage Microorganisms
• Some species such as Staphylococcus aureus tend to be outcompeted
by other harmless flora or spoilage bacteria that lead to a bad odor
that cause most consumers to discard the meat.
• The predominant bacteria associated with spoilage of refrigerated
beef and pork, are Brochothrix thermosphacta, Carnobacterium spp.,
Enterobacteriaceae, Lactobacillus spp., Leuconostoc spp.,
Pseudomonas spp. and Shewanella putrefaciens
• The main defects in meat are off-odours and off-flavours, but
discolouration and gas production also occur. Bacteria associated with
the spoilage of refrigerated meat products, causing defects such as
sour off-flavours, discolouration, gas production, slime production
and decrease in pH, consist of B. thermosphacta, Carnobacterium spp.
Luctobacillus spp. Leuconostoc spp. and Weissella spp
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12. Molds
• Mycotoxin are the secondary metabolites that has adverse effect on animal
health
• Mycotoxin are produced by the various species of molds, among which are
most common belong to the Aspergillus, Penicillium, Claviceps and Fusarium
genera
• Mycotoxin can be reached to the meat and meat products in two ways:
1. Through the consumption of Meat and Meat products from animal which
have recently consumed feed contaminated with mycotoxins
2. Through the growth of toxigenic molds on the surface of cured and rippened
meat products.
• Animal who are consuming the mold through meat and meat products can have
diverse susceptibility to mycotoxins, varying from death cause by its acute
intoxication to subclinical mycotoxicosis caused by long term administration of
low doses of mycotoxins.
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13. Mold In Salami Mold In Beef
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14. References:
https://www.ncbi.nlm.nih.gov/pubmed/3993251
https://www.researchgate.net/publication/325216644_Microbiological_
and_hygienic_quality_of_Meat_and_Meat_Products
https://www.slideshare.net/HajarAzhari/microbiology-of-meat
https://aem.asm.org/content/82/13/4045
Doulgeraki AI, Ercolini D, Villani F, Nychas GJE. 2012. Spoilage
microbiota associated to the storage of raw meat in different conditions.
Int J Food Microbiol 157:130–141.
doi:10.1016/j.ijfoodmicro.2012.05.020.
Kumar CG, Anand S. 1998. Significance of microbial biofilms in food
industry: a review. Int J Food Microbiol 42:9–27. doi:10.1016/S0168-
1605(98)00060-9.April 10, 2020
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