5/20/2015. Oral & GI Diseases: Overview. Oral & GI Diseases: Bacterial. Oral & GI Diseases: Bacterial. Oral & GI Diseases: Viral.

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1 5/20/2015 Unit 10 Microbial Diseases Part 2 and Applied Microbiology CH 22, Oral & GI Diseases: Overview Components of the digestive system: Organs: Mouth, pharynx, esophagus, stomach, & intestines Accessory organs: teeth, salivary glands, liver, gallbladder, & pancreas 5 major functions: food movement, secretion, digestion, absorption, & elimination Dental plaque: a yellowish biofilm that builds up on the teeth Periodontal disease: combination of gingivitis & erosion of bone that supports teeth Streptococcus mutans (normal microflora) Will turn calcified and become tartar (or calculus) if not removed Dental caries tooth decay : chemical dissolution of enamel and deeper parts of the teeth Affects over 80% of teens and adults Major cause of tooth loss The use of fluoride is the best preventative treatment because it strengthens tooth enamel Gingivitis: inflammation of the gums caused by trapped bacteria Brain Check Mumps: contagious disease that is usually diagnosed with the appearance of swollen salivary glands ; Mumps (paramyxovirus) virus 1. What is the difference between plaque and tartar? Entry: saliva or aerosol droplets via mouth or respiratory tract In males, can cause swollen testes = sterililty 2. Why does fluoride help fight tooth decay? No cure; MMR vaccination is the best preventative method 3. What two organs can swell due to mumps? 1

2 5/20/2015 food poisoning: ingestion of food with bacterial toxins enteritis & enteric diseases S. aureus, C. botulinum & perfringrens, E. coli O157:H7 Symptoms are more rapid than getting a bacterial infection Enterotoxins are made that inflame the intestinal lining, prevent water absorption from the intestines, & neural stimulation of the vomiting center of the brain Small intestine: enteritis (mild diarrhea) Large intestine: dysentery (severe diarrhea that can contain mucus, blood, & even pus) Salmonellosis, typhoid fever, shigellosis, Asiatic cholera, & traveler s diarrhea are all classified as this Poor sanitation or infected water/food Diarrhea used to be the cause of many infant deaths Salmonellosis: Caused by the genus Salmonella (typhi, enteritidis, chloeraesuis) Salmonella strains are often found in the GI tracts of many animals like poultry, wild birds, reptiles, & rodents Due to ingestion of improperly prepared, previously contaminated food (meat & dairy products) Shigellosis: less invasive than salmonellosis Spread by contaminated food, fingers, feces, flies, & fomites Outbreaks occur in daycares frequently Leading cause of infant disease in developing countries because it leads to dehydration Asiatic Cholera: caused by Vibrio cholerae Traveler s diarrhea Montezuma s revenge : can outbreak anywhere sanitation is poor and fecal matter exists in the water a mild to severe diarrhea occurs in almost half of international travelers every year as many as 22 liters of fluids and electrolytes can be lost per day treatment involves replacement of fluid and electrolyte loss most common cause is E. coli which is responsible for 40 95% of the cases most deaths occur due to loss of fluids which makes the blood more viscous and causes shock About 6% of patients develop kidney issues which can lead to kidney failure 2

3 Brain Check Peptic ulcers: caused by Helicobacter pylori lesions on the mucous membrane of the esophagus, stomach or duodenum As of yet, no one has determined the route of infection or portal of exit for the bacteria Treatment: antibiotics can be used to cure the infection but must be done carefully & they cannot cure it 1. Describe the difference between diarrhea and dysentery. 2. Why would traveler s be advised not to take antibiotics before and during a trip to avoid traveler s diarrhea? Viral enteritis: Caused by Rotavirus transmitted by the fecal-oral route, replicate in the intestine, damage the intestinal epithelium and cause water diarrhea it is one of the common causes of infant mortality in developing countries, up to 1/3 treatment is to restore fluids and keep electrolytes balanced Hepatitis HAV is the most common viral hepatitis & is transmitted via the fecal-oral route; jaundice, malaise, nausea, diarrhea, abdominal pain and lack of appetite are common signs and symptoms. Recovery is usually complete and lifelong immunity is acquired. There is a vaccine available. HBV is transmitted via contaminated bodily fluid. Signs and symptoms are similar to HAV but it can be chronic and destroy liver cells. There is a vaccine for HBV that is 95% effective. Oral & GI Diseases: Parasitic HCV is transmitted by blood and is the leading reason for liver transplants HDV must be a superinfection with HBV to cause disease because it cannot do it alone & then it becomes a severe infection HEV is transmitted via the fecal-oral route and causes large outbreaks moreso in adults than children; no vaccine or conferred immunity Giardiasis caused by Giardia lamblia, an intestinal parasite that attaches itself to the intestinal wall, causing watery diarrhea or oily feces, nausea, stomach pains and fatigue Normal sewage treatment and chlorination does not kill Giardia cysts found in the US in lakes and streams Hitchhiker's Disease 3

4 Oral & GI Diseases: Parasitic Oral & GI Diseases: Helminths Amebiasis Caused by Entamoeba histolytica can live in the large intestine (colon) without causing damage to the intestine. In some cases, it invades the colon wall, causing colitis, acute dysentery, or longterm (chronic) diarrhea. The infection can also spread through the blood to the liver. In rare cases, it can spread to the lungs, brain, or other organs Fluke infections caused by foodborne flukes like Fasicola hepatica Verminous intoxication: allergic reaction to their wastes Tapeworm infections Can become meters long & cause malnutrition & intestinal blockage Hookworm infections Diseases of the Nervous System- Meningitis Inflammation of the meninges; types relate to the age of the host Meningococcal meningitis: infants-24 years of age Heamophilus meningitis: infants, but vaccinations help; we acquire immunity quickly so it s rare in adults S. pneumoniae meningitis: most common in adults with 40% mortality Listerioisis: Caused by Listeria monocytogenes Another type of meningitis caused by usually caused by eating contaminated food (milk, cheese, meat, & vegetables) an important public health problem in the United States Fetal complications: miscarriage, stillbirth, or neonatal death Leading cause of infection in kidney transplant patients Treatment: antibiotics Hansen s Disease: Caused by Mycobacterium leprae Affects the nerves & eventually deforms hands & feet Can be tuberculoid: areas of skin lose sensation & pigment or lepromatous: forms large, disfiguring skin lesions or lepromas Treatment: can reduce lepromas, but cannot restore lost tissue Tetanus: Caused C. tetani Tetanus bacteria are everywhere in the environment & they get through broken skin, usually through injuries from contaminated objects Treatment: wound care, tetanus shot, vaccination, drugs for muscle spasms 4

5 Viral Botulism Caused by Clostridium botulinum Neuroparalytic disease; most potent toxin (1 oz. can kill the US pop.) Foodborne: improperly canned foods (green beans, green peppers) Infant botulism: feeding honey to babies Wound botulism: rare Treatment: antitoxin because it is a toxin (written wrong on your notes) Rabies preventable viral disease of mammals most often transmitted through the bite of a rabid animal (raccoons, skunks, bats, and foxes) infects the central nervous system, ultimately causing disease in the brain and death Early symptoms of rabies: fever, headache, and general weakness or discomfort; As the disease progresses, may include insomnia, anxiety, confusion, slight or partial paralysis, excitation, hallucinations, agitation, hypersalivation (increase in saliva), difficulty swallowing, and hydrophobia (fear of water) Treatment: wound care & vaccine Viral Encephalitis Inflammation of the brain; transmitted by mosquito bites Eastern Equine Encephalitis (EEE): eastern US; causes necrotizing infection of the brain (most severe) Western Equine Encephalitis (WEE): western US; every summer St. Louis Encephalitis (EEE): central US; late summer epidemics Symptoms: fever, headaches, convulsions Treatment: no specific antiviral drugs Parasitic African Sleeping Sickness also called Trypanosomiasis Caused by Trypanosoma brucei carried by the tsetse fly; can be transmitted from mother to child causes coordination problems, fatigue and general confusion Treatment success in the second stage depends on a drug that can cross the blood-brain barrier to reach the parasite; only 4 drugs for treatment Environmental Microbiology Water Pathogens 5

6 Water Purification Determined by the degree of purity at the water source Little treatment needed for: well water or reservoirs fed from clean mountain streams Extensive treatment: rivers that contain industrial, animal wastes, and even sewage Water Purification 3 basic methods in holding reservoirs: 1. Flocculation: causes particulates to clump together and either float or sink, followed by treatment with alum; also removes a lot of microbes 2. Filtration: passing water through beds of sand to remove nearly all remaining microbes 3. Chlorination: addition of chlorine; kills bacteria, but less effective with viruses & cysts of pathogenic protozoa Water Purification Bioremediation Physical removal of solid wastes Biological removal of solid wastes by aerobic bacteria Physical & chemical removal of solid wastes Being replaced by UV Bioremediation a waste management technique that involves the use of organisms to remove or neutralize pollutants from a contaminated site 1. break down the hydrocarbons of oil into carbon dioxide 2. toxic metals, such as mercury (II), can be converted into nontoxic forms 3. can remove oil, some pesticides, fertilizers, and toxic chemicals, such as arsenic, from the environment Food Production Microbiology Microbes Found in Food Grains: only become a problem if grains become wet Produce: millions of commensal bacteria on their surfaces; contamination from soil, animals, air, irrigation water, and equipment Meats/Poultry: arrive at the slaughterhouse with various microbes in their gut & feces, on their hides & hoofs, and sometimes in their tissue; even once slaughtered, molds can take over or cysts remain in the meat Fish/Shellfish: contain an abundance of microbes & because they are freely eaten raw, can cause major concerns Milk: modern techniques help reduce microbial counts, but selective breeding has led to larger udders therefore they can hold more milk & bacteria 6

7 Preventing Disease and Food Spoilage Industrialization & mass food production has increased the spread of foodborne pathogens Canning: most common method of food preservation; if done correctly, food can remain edible for years Refrigeration/ Freezing: bacteriostatic; refrigeration is only good for a few days & freezing for a few months Drying: oldest method of food preservation; also bacteriostatic; adding high amounts of salt and sugar help; removal of about 90% of water Food Preservation Methods Irradiation Chemical Preservatives Pasteurization Microbes as Food Fungi: mushrooms & yeast Algae: mariculture Bacteria: bacteria in lakes cooked into cakes Microbes in Food Production Baked goods Cheese/Dairy Vinegar Sauerkraut and pickles Green olives Poi Soy products Fermented meats Beer, wine, & spirits 7