How do bacteria make us sick WARM UP

How do bacteria make us sick?

WARM UP! • How Do Bacteria Make Us Sick? • Do All Bacteria Make Us Sick?

How Do Bacteria Make Us Sick? 1. Most times, bacteria that live in our body are commensalistic, or live in our body and do not cause us any harm. 2. However, if that bacterium finds its way into another area of our body, that is when they will begin to cause harm.

How Do Bacteria Make Us Sick? 3. They can be passed from organism to organism through several different paths 1. 2. 3. 4. 5. contact with other organisms, through the food we eat, through water we drink and bathe in, from the air from the soil.

How Do Bacteria Make Us Sick? 4. Once the bacteria find their way into a new, warm, and moist environment, they will begin to grow and take in nutrients from their host – they become parasitic.

Harmful Bacteria • some bacteria cause diseases • Animals can pass diseases to humans Communicable Disease – Disease passed from one organism to another This can happen in several ways: • Air • Touching clothing, food, silverware, or toothbrush • Drinking water that contains bacteria 6

Harmful Bacteria Human tooth with accumulation of bacterial plaque (smooth areas) and calcified tartar (rough areas) 7

How do they get to new locations? • Pili are cilia like hairs on the outside of the organism and move in a wave like motion to the intended location. – pili will grow and anchor the bacteria into the cellular lining of the organism – bacteria will now be able to multiply without being washed away from their location.

How do they get to new locations? • Other bacteria have flagella, a whiplike tail that thrashes back and forth, that will allow them to swim to the intended location.

Making us sick… • Some bacteria will secrete an endotoxin that will cause their host to become severely ill – inducing vomiting or diarrhea. – This weakens the host’s defenses and makes it harder for the bacteria to be killed off by the immune system. – Other bacteria have evolved a way to enter into the cell and consume the cellular material in that area.

Streptococcal pharyngitis (Strep throat ) • Strep throat is caused by Group A Streptococcus bacteria. It is the most common bacterial infection of the throat. • Strep throat is spread by person-to-person contact with nasal secretions or saliva. It commonly spreads among family or household members.

Streptococcal pharyngitis (Strep throat ) • Symptoms may be mild or severe. You usually start to feel sick about 2 to 5 days after you come in contact with the bacteria. • typical symptoms: sore throat, fever of greater than 38 °C (100 °F), pus on the tonsils, and large cervical lymph nodes. • is diagnosed in 11 million people annually in the United States

Mycobacterium tuberculosis (Tuberculosis or TB) • disease affects 1. 8 billion people/year which is equal to one-third of the entire world population • Humans are the only reservoir for the bacterium. • usually attack the lungs, but TB bacteria can attack any part of the body such as the kidney, spine, and brain. • TB disease can be fatal

Mycobacterium tuberculosis (Tuberculosis or TB) • is spread through the air from one person to another. The TB bacteria are put into the air when a person with active TB disease of the lungs or throat coughs, sneezes, speaks, or sings. • a bad cough that lasts 3 weeks or longer; pain in the chest; coughing up blood or sputum; weakness or fatigue; weight loss; no appetite; chills; fever; sweating at night • Can be treated with antibiotics, however, strains are becoming antibiotic resistant.

Staphylococcal aureus (Staph Infection) • It is frequently found as part of the normal skin flora on the skin and nasal passages. • It is estimated that 20% of the human population are long-term carriers of S. aureus. – can cause a range of illnesses, from minor skin infections, such as pimples, boils – to life-threatening diseases such as pneumonia, – meningitis, – toxic shock syndrome (TSS), and sepsis.

Staphylococcal aureus (Staph Infection) • Some strains are MRSA - Methicillin-resistant Staphylococcal aureus – are antibiotic resistant • MRSA strains are most often found associated with institutions such as hospitals, but are becoming increasingly prevalent in community -acquired infections.

Salmonella enterica Salmonellosis • Food poisoning • caused by food infected with S. enterica, which often infects cattle and poultry, though also other domestic animals have also been shown to be sources of infection to humans. • Raw chicken eggs and goose eggs can harbor S. enterica, • As the egg ages at room temperature, the yolk membrane begins to break down and S. enterica can spread into the yolk. • Refrigeration and freezing substantially slow or halt their growth. • Pasteurizing and food irradiation are used to kill Salmonella for commercially-produced foodstuffs containing raw eggs such as ice cream.

Salmonella enterica Salmonellosis • develop diarrhea, fever, and abdominal cramps 12 to 72 hours after infection. The illness usually lasts 4 to 7 days, and most persons recover without treatment. • Some develop diarrhea so severe that the patient needs to be hospitalized. – Salmonella infection may spread from the intestines to the blood stream, and then to other body sites and can cause death unless the person is treated promptly with antibiotics.

Not all bacteria make us sick…. These bacteria protect us by competing with pathogenic species of bacteria, and creating a healthy environment. Other benefits of these beneficial bacteria are that they help us to convert or absorb certain vitamins, eliminate toxins, or help to breakdown digested food.

Helpful Bacteria • Decomposers help recycle nutrients into the soil for other organisms to grow • Bacteria grow in the stomach of a cow to break down grass and hay • Most are used to make antibiotics • Some bacteria help make insulin • Used to make industrial chemicals 20

Helicobacter pylori • Gut dwelling species • Elimination of H. pylori actually increases the risk of gastric reflux, which is associated with asthma and esophageal diseases; is an indicator organism for microbiota. • A spiral shaped organism with flagella, it has a potent enzyme that enables it to survive in acidic p. H conditions and colonize the gastric environment.

Bacteroides fragilis • Bacteroides fragilis also competes with other organisms inside the colon/intestinal lumen for nutrients and food. This can be of great benefit to our body because when organisms compete, it decreases the availability of nutrients for other dangerous pathogens to grow, harming our body.

Bacteroides fragilis • Once B. fragilis leaves the lumen and travels to adjacent areas and organs, it can be detrimental, for it contributes to a variety of infections in the upper body, abdomen, skin and many others. • invades its host by producing the enterotoxins. It can survive and adapt in most environment.

Lactobacillus bulgaricus • Helpful bacteria used in the production of cheese and yogurt, symbiotic micro-organisms that can shrink or multiply within the environment of the mucous lining in the gastro-intestinal tract, an interface between the absorption of needed nutrients and the diversion of harmful microbes and toxins. • No negative affects known thus far…

Escherichia coli • Most varieties are harmless or cause relatively brief diarrhea. E. coli contributes to the manufacture of vitamin K and vitamin B 12 and fosters the synthesis of vitamin K and B complex vitamins like B 6 and B 12 in our bodies. • But a few particularly nasty strains, such as E. coli O 157: H 7, can cause severe abdominal cramps, bloody diarrhea and vomiting.

Escherichia coli • outbreaks can occur when food or water gets contaminated with this bacteria • Can cause diarrhea and urinary tract infections (UTIs)

Streptococcus thermophilus • The most commercially important of the lactic acid bacteria is known to promote gastrointestinal health. • A starter strain is used to make yogurt. It lacks the genes that contain the surface proteins harmful bacteria use to attach to mucosal tissues and hide from the body’s defensive actions.

ACTIVITY due by end of class • Fill in the bacteria organizational chart. • Now create a comic strip about bacteria. MUST INCLUDE: – Types – Shapes – Reproduction – bianary fission, transduction, conjugation, transformation (from the reading on Friday) – Harmful? Beneficial? Must Be colorful. Must have 8 segments. Does not have to be funny. . But comedy helps.