Micro Lect 23 Chapter 23 Notes p.549-581

Germ-free studies clearly show role of microbes in creating caries. Strep. mutans = major participant in crevices, Strep. sobrinus on smooth surfaces. Thick layer invites several anaerobes

Periodontal disease very preventable with flossing, brushing. (Toothpaste may have too many abrasives.) No floss = open portal for blood-borne heart infection!

Mumps: virus in salivary glands, can go to testes. Vaccinate: MMR.

Shigella: Lac^- E. coli? Fecal-oral. Day care centers (½ <5). Antibiotic resistant strains

Salmonella. typhi: typhoid fever. Fecal-oral. Antibiotic resistance.

Salmonellosis: S. enteritidis, S. choleraesuis Food. Diarrhea, cramps, fever. Don't use antibiotics

E. coli O157:H7: can kill.

V. cholerae: cholera. Oral rehydration essential, antibiotics shorten duration. Unethical expts.?

V. parahaemolyticus:mild, self-limiting. 1/4 of Japanese cases.

Yersinia enterocolitica: severe enterocolitis. Animals, raw milk, oysters, water.

Campylobacter jejuni: bloody diarrhea, pain, fever. Most common U.S. diarrheal cause.

Helicobacter pylori: most ulcers, some cancers.

Clostridium difficile Tetracycline can precipitate colitis. Stop antibiotic; residents back

S.aureus: most common food poisoning in U.S. Rich foods, but acidic mayo helped. Sudden.

Bacillus cereus: mild, brief.

C. perfringens: brief, mild.

Viruses not serious, unless child dehydrated.

Protozoans:

E. histolytica (amoeba. Antibiotics can help; kill food bacteria ), Giardia lamblia, Balantidium coli(tropical ciliate), Cryptospiridium(AIDS problem)

Helminths

Enterobius vermicularis (pin worms). Vacuum compulsively! Worms lay eggs at night.

Ascaris lumbricoides: (nematode). Ingest eggs, hatch and through intestinal wall to lungs, cough and swallow)

Ancyclostoma duodenale, Necator americanus. (Nematode hookworms). Soil worms penetrate barefoot skin, to lungs, coughed, swallowed. Diarrhea, vomiting, malnutrition, anemia

Strongyloides stercoralis (nematode)Through skin to lungs, etc. AIDS death.

Trichuris trichiura wall of small intestine. Heavy infest. Bloody diarrhea, weight loss, etc.

Trichinella spiralis (trichinosis) encyst in muscles. Thoroughly cook or freeze meat. Handling.

Taenia spp. Tapeworm (great diet pill: tapeworm eggs.) Cook meat to prevent.

Echinococcus granulosus Good hygiene to prevent, surgical removal of cysts

Liver infections:

hepatitis A (infectious, vaccinate, usually self-limiting), B(serum hepatitis, liver cancer causation, spreads like HIV, vaccinate) C (6 month incubation, 1/4 of infected=chronic inf. And liver disease), D (delta agent-infects HBV-infected. Chronic infn.= fatal liver disease), E (like HAV, but 20% of pregnant pts. Die!)

Fasciola hepatica (sheep liver fluke); Opisthorchis sinensis (Chinese liver fluke). Prevent fecal contamination of water, don't wade in water!

Reactions to food additives (http://www.faia.org.uk/booklet.pdf)

It is difficult to obtain reliable figures on the incidence of intolerance to additives and a link with hyperactivity but some things are clear. People who are severely allergic, eg asthmatics, hay fever and urticaria sufferers, sometimes suffer intolerance to some additives. But this is a part of a general problem.The additives have not created their condition. In a study conducted by questionnaire in the UK,

7% of those responding claimed that they reacted badly to food additives, but in follow-up tests only 1-23 in 10,000 ( 0.01-0.23%) proved to be intolerant to additives. The same UK study showed that about 1 in 70 people reacted badly to a number of common foods, including cow's milk, hen's eggs, wheat, soya, oranges, prawns and nuts. In other words, intolerance to everyday foods is much more widespread than intolerance to additives.