Investigating DiseasesCaused by:

Bacteria, Protists and Fungi

PATHOGENS

• Disease causing agents

PARASITES

• Organisms that live in or on a host organism and harm the host.

• Parasites that cause disease are also considered pathogens.

Contact with Contaminated Objects

Inhalation of Droplets(Ex: colds & flu)

Contact with Blood or Body Fluids(Ex: semen, urine, mucus, saliva)

Contact with Contaminated Food or Water

(Ex: chicken, eggs, untreated water)

Spread by Vectors

MosquitoFleas

and Ticks

Bacteria as Pathogenic Parasites

• Bacteria can harm their host by

–i. Damaging cells as they break them down for food

–ii. Secreting poisonous toxins

Examples of Bacterial Diseases

• Staph Infection

• Strep Throat

• Gonorrhea

• Anthrax

• What trait do all members of kingdom Protista share in common?

HINT

Protists as Parasitic Pathogens

• A. Some members of kingdom Protista act as ___PATHOGENS______ causing diseases in humans.

B. Example of diseases caused by protists:

• 1. __Malaria_______ – caused by the protist Plasmodium. Its vector is the mosquito.

• Symptoms: fever, chills, headache, nausea, vomiting

Plasmodium (causes malaria)

• 2. _Giardia – a protist that causes severe diarrhea. It is transmitted through contaminated water

Giardia lamblia

• 3. _African sleeping sickness— caused by a protist carried by the tsetse fly.

African Sleeping Sickness (Trypanosoma brucei gambiense)

WHAT ARE TRAITS OF KINGDOM FUNGI?

• LIST SOME TRAITS OF FUNGI IN YOUR NOTES IN THE SPACE PROVIDED.

• Are they autotrophs or heterotrophs?

• Do they have a cell wall?

• Are they unicellular or multicellular?

Fungi as Parasitic Pathogens

• A. Some members of kingdom _____FUNGI_________ act as pathogens causing diseases in humans.

B. Examples:

1.RINGWORM2. ATHLETE’S FOOT3. THRUSH (caused by yeast)

RINGWORM

Often passed from pets to

their owners.

DAMAGE FROM ATHLETE’S FOOT

Athlete’s Foot

Causes cracked, flaking, and peeling of skin between the toes. The affected area is usually red and itchy. You may feel burning or stinging, and there may be blisters, oozing, or crusting.

Your risk for getting athlete's foot increases if you: •Wear closed shoes, especially if they are plastic-lined•Keep your feet wet for prolonged periods of time•Sweat a lot•Develop a minor skin or nail injury

Athlete's foot is contagious, and can be passed through direct contact, or contact with items such as shoes, stockings, and shower or pool surfaces.

Thrush of the tongue

Examples of Bacterial Diseases

• Botulism

• Strep Throat

• Staph Infection

• Gonorrhea

• Pneumonia

• Tetanus

• Anthrax

• Bubonic Plague

Worksheet-Diagnosing Diseases

• Using the information you have in your notes and the information presented on the next slides, complete the Worksheet “Diagnosing Diseases.”

Anthrax

• Anthrax is an animal disease that has been around for tens of thousands of years. Rarely, anthrax causes serious disease in humans. The germ is a bacterium called Bacillus anthracis that "seeds" itself by forming long-lasting spores.

• People can catch anthrax from infected animals or contaminated animal products. Most natural infection comes from skin contact.

• Skin infection starts with an itchy bump like a mosquito bite. After a day or two, it forms a small liquid-filled sac. This sac then becomes a painless ulcer with an area of black, dead tissue in the middle. Antibiotic treatment cures this infection. Untreated, it kills about one in five people.

Bacillus anthracis

Botulism

• Botulism is a rare but serious paralytic illness caused by a nerve toxin that is produced by the bacterium Clostridium botulinum.

• There are three main kinds of botulism. Foodborne botulism is caused by eating foods that contain the botulism toxin. Wound botulism is caused by toxin produced from a wound infected with Clostridium botulinum. Infant botulism is caused by consuming the spores of the botulinum bacteria, which then grow in the intestines and release toxin. All forms of botulism can be fatal and are considered medical emergencies. Foodborne botulism can be especially dangerous because many people can be poisoned by eating a contaminated food.

• The classic symptoms of botulism include double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth, and muscle weakness. In foodborne botulism, symptoms generally begin 18 to 36 hours after eating a contaminated food, but they can occur as early as 6 hours or as late as 10 days.

Clostridium botulinum.

Gonorrhea

• Also called the "clap" or "drip," gonorrhea is a contagious disease transmitted most often through sexual contact with an infected person. Gonorrhea may also be spread by contact with infected bodily fluids, so that a mother could pass on the infection to her newborn during childbirth or to her baby through household contact. Both men and women can get gonorrhea. The infection is easily spread and occurs most often in people who have many sex partners.

• Gonorrhea is caused by Neisseria gonorrhoeae, a bacterium that can grow and multiply easily in mucus membranes of the body

Gonorrhea

• Symptoms in women • Greenish yellow or whitish discharge from the vagina • Lower abdominal or pelvic pain • Burning when urinating • Conjunctivitis (red, itchy eyes) • Bleeding between periods • Spotting after intercourse • Swelling of the vulva (vulvitis) • Symptoms in men • Greenish yellow or whitish discharge from the penis • Burning when urinating

Gonorrhea

Neisseria gonorrhoeae

Bubonic Plague

• Plague is an infectious disease caused by bacteria called Yersinia pestis. These bacteria are found mainly in rodents, particularly rats, and in the fleas that feed on them. Other animals and humans usually contract the bacteria from rodent or flea bites.

• Historically, plague destroyed entire civilizations. In the 1300s, the "Black Death," as it was called, killed approximately one-third (20 to 30 million) of Europe's population. In the mid-1800s, it killed 12 million people in China. Today, thanks to better living conditions, antibiotics, and improved sanitation, current World Health Organization statistics show there were 2,118 cases in 2003 worldwide.

• Bubonic plague affects the lymph nodes (another part of the lymph system). Within three to seven days of exposure to the bacteria, flu-like symptoms will develop such as fever, headache, chills, weakness, and swollen, tender lymph glands (called buboes-hence the name bubonic).

Bubonic Plague

Yersinia pestis

Pneumonia

• Pneumonia is inflammation or swelling in the lungs in which the air sacs fill with pus and other fluids, making it difficult for oxygen to reach the blood. Pneumonia can be typical or atypical. Typical pneumonia is most commonly caused by Streptococcus pneumoniae, also known as the pneumococcal pneumonia.

• Pneumonia can be spread through droplets which are transmitted through the air and then inhaled.

• Symptoms of bacterial pneumonia can develop gradually or suddenly. Symptoms include: – High fever (up to 105 degrees) – Drowsiness – Rapid breathing – Chills – Cough with mucus (may be greenish or have blood) – Chest pain – Blue tint on lips or under the nails (severe cases)

Pneumonia

Visible swelling of lung tissue

Streptococcus pneumoniae

Staph Infection

• A type of infection caused by a Staphylococcus (or "staph") bacteria. Actually, about 25% of people normally carry staph in the nose, mouth, genitals, and anal area. The foot is very prone to pick up bacteria from the floor. The infection often begins with a little cut, which gets infected with bacteria.

• These staph infections range from a simple boil to antibiotic-resistant infections to flesh-eating infections. The difference between all these is how deep and how fast the infection spreads, and how treatable it is with antibiotics. The antibiotic-resistant infections are more common in North America, because of our overuse of antibiotics.

• The staph infection is contagious if the wound is weeping or draining, and if people share towels or other items that are contaminated. Wearing foot coverings in locker rooms and other commonly used areas can help prevent contamination.

Staph

• Infects Wounds

• Sores and blisters on skin

Staphylococcus

Strep Throat

• Strep throat is caused by bacteria of the genus Streptococcus.

• A strep infection causes the throat (pharynx) and the tonsils or adenoids to become irritated, inflamed, and painful.

• Strep throat can be passed from person to person. When a person infected with strep throat breathes, coughs, or sneezes, tiny droplets containing the strep bacteria are released into the air and are breathed in by other people. It is also spread through direct contact with mucus from the nose or throat of infected persons.

Strep Throat

• Sore throat

• Difficulty swallowing

Streptococcus

Tetanus

• Tetanus is a dangerous nerve ailment caused by the toxin of a common bacterium, Clostridium tetani.  Bacterial spores are found in soil -- most frequently in cultivated soil, least frequently in virgin soil.  The spores can remain infectious for more than 40 years in soil. If the spores enter a wound that penetrates the skin and extends deeper than oxygen can reach, they germinate and produce a toxin that enters the bloodstream.

• It is contracted through a cut or wound that becomes contaminated with tetanus bacteria. Wounds contaminated with soil, saliva, or feces - especially if not properly cleaned - and skin punctures from nonsterile needles (such as with drug use or self-performed tattooing or body piercing) are also at increased risk.

• Symptoms– Stiffness of the neck, jaw, and other muscles, often accompanied by a

grotesque, grinning expression. – Irritability. – Uncontrollable spasms of the jaw and neck muscles. – Painful, involuntary contraction of other muscles.

Tetanus

Clostridium tetani