How are they classified? Objective 8.L.1 – Summerize the basic characteristics of viruses, bacteria, fungi, and parasites relating to the spread, treatment, and prevention of disease. KEY QUESTIONS What are Pathogens? How are they classified? Are they good or bad?

What are Pathogens? A pathogen or infectious agent is a Microorganisms that are capable of causing disease or illness to its host.

What are Pathogens? Pathogens can be single celled organism (one cell that carries out all life processes) Pathogens can be multicellular celled organism (many cells work togerther to carry out all life processes) Pathogens can be Eukaryotic (genetic material is enclosed in nucleus) Pathogens can be prokaryotic (lack a distinct nucleus and membrane bound organelles Pathogen can be parasites (an organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host's expense. E. coli Salmonella USDA NIFSI Food Safety in the Classroom© University of Tennessee, Knoxville 2006

What are examples of pathogen? A biological organism such as Bacteria, Viruses, Fungi, and Protozoa that make you sick. Why do they make you sick? To get the energy they need to survive and reproduce How do they make you sick? They produce poisons (toxins) that result in fever, headache, vomiting, and diarrhea and destruction of body tissue. USDA NIFSI Food Safety in the Classroom© University of Tennessee, Knoxville 2006

Where do you get a pathogen? Direct or indirect Contact Inhalation of dust or water droplets that have come into contact with, or produced by an infected host Direct contact with an infected host Contact with objects/foods that have been contaminated Contact with vectors carrying the bacterium.

What are bacteria? Single celled organisms There are countless numbers of bacteria on the Earth but less than 1% of them cause diseases. Very small..need a microscope to see Some people can be infected by bacteria and not show symptoms, these people are known as carriers. This is a pore in human skin and the yellow spheres are bacteria Streptococcus can cause strep throat. This E. coli helps you digest food. Anthrax

What do they look like? Three basic shapes Rod shaped called bacilli (buh-sill-eye) Round shaped called cocci (cox-eye) Spiral shaped Some exist as single cells, others cluster together Bacilli Cocci Spiral Cluster of cocci USDA NIFSI Food Safety in the Classroom© University of Tennessee, Knoxville 2006

What are some common bacteria? E. coli O157:H7 Pathogenic E. coli (like O157:H7) Found in ground beef, contaminated fruits and vegetables Salmonella Found in raw meats, poultry, eggs, sprouts, fruit and vegetables Listeria Found in deli foods, lunch meats, smoked fish and vegetables Salmonella USDA NIFSI Food Safety in the Classroom© University of Tennessee, Knoxville 2006 Listeria

Bacteria are ALIVE! What does it mean to be alive? Bacteria are alive because they can… reproduce (make more of themselves) need to eat USDA NIFSI Food Safety in the Classroom© University of Tennessee, Knoxville 2006

How do bacteria reproduce? Grow in number not in size Humans grow in size from child to adult Make copies of themselves by dividing in half. This is done very quickly. Human parents create a child USDA NIFSI Food Safety in the Classroom© University of Tennessee, Knoxville 2006

How are Bacteria infections treated? Body fluids can be sampled and cultured to grow and identify the bacterial pathogen. Antibiotics are the usual treatment for bacterial infections, but treatment can vary. Bacteria adapt quickly and may become resistant to antibiotics. Strangles in horses is caused by Streptococcus equi bacteria A broad spectrum antibiotic A positive culture for Streptococcus bacteria Images from: http://informedfarmers.com/horse-strangles-disease/ http://www.valleyvet.com/ct_detail.html?pgguid=30e07521-7b6a-11d5-a192-00b0d0204ae5 http://pediatrics.about.com/od/childhoodinfections/ig/Strep-Throat-Tests/A-Positive-Culture-for-Strep.htm References: http://www.omafra.gov.on.ca/english/livestock/horses/facts/03-037.htm

Viruses

What are Viruses? Considered Non-Living and Viruses are not cells A virus consists of two parts: a piece of genetic material (RNA) that is housed within a protective coat. The virus reproduces by hijacking the cell of another organism (host) and getting the host cell to reproduce more viruses. Influenza Ebola Currently, viruses are not considered living organisms, but there is debate among the scientific community on this topic. Images from: http://www.sciencephoto.com/images/imagePopUpDetails.html?pop=1&id=770501166&pviewid=&country=67&search=&matchtype=FUZZY Rabies Virus HIV

Why are Viruses not considered alive? Viruses are not considered "alive" because they lack many of the properties that scientists associate with living organisms. Primarily, they lack the ability to reproduce without the aid of a host cell, and don't use the typical cell- division approach to replication

What is the Treatment? Treating viral infections is more difficult that treating bacterial infections because it is difficult to attack a virus without attacking host cells as well. Treatments are usually involves treating the symptoms. This can include administering fever reducers and allowing the animal to rest. Mainly the virus had to run its course. Focus on prevention by administering vaccinations Prevention is the key Get a vaccination

Diseases cased by Viruses Avian or Bird Flu Swine Flu Meningitis Mononucleosis Warts Hepatitis Bronchiolitis Colorado Tick Fever Encephalitis Common Cold HIV-AIDS Influenza (Flu) Measles (Rubella) Mumps Polio Rabies Smallpox Hepatitis Herpes

Kingdom Protista

Protista can be Pathogens The Protista kingdom includes Algae, and Protozoans. They may have features like those of plants, animals, and fungi. They may be single celled or multicellular.

Protist can reproduce sexually or asexually Meiosis Budding and Fission

Groups are based on movement . This includes movement by How do they move ? Groups are based on movement . This includes movement by flagella, cilia, pseudopods . false feet’ Euglena Paramecium Amoeba Hair like structure Streaming cytoplasm Whip like structure

Fungi

What is a Fungi? Fungi are Eukaryotic heterotrophs and are unicellular and multicellular Some live as saprophytes (live on rotting organic matter) They perform a crucial role in nature by decomposing dead organisms Some live in a mutually beneficial symbiotic relationship

How do Fungi Reproduce Asexually They produce spores Sexually Budding – Buds that break of from the parent and produce an identical copy Meiosis – sharing DNA wit similar fungi

Examples of Fungi molds yeasts Mushrooms mildews Yeast: Candida albicans mildews

How can I avoid getting sick from pathogens? Wash your hands often Warm water with soap for 20 seconds, rub hard between fingers and nails Cook food thoroughly to kill any pathogens that may be in your food Store food properly to limit pathogen growth Cold temperatures (40F) Use Antiseptic and Disinfectants . USDA NIFSI Food Safety in the Classroom© University of Tennessee, Knoxville 2006

Review Bacteria are prokaryotic and unicellular. Bacteria have cell walls. Bacteria have circular DNA called plasmids Bacteria can be anaerobes or aerobes. Bacteria are heterotrophs or autotrophs. Bacteria are awesome!

Review Bacteria, Fungi, and Protista are living organisms Most are harmless A few are pathogens that make you sick You can reduce the risk of getting sick by washing your hands and handling food properly. USDA NIFSI Food Safety in the Classroom© University of Tennessee, Knoxville 2006