Ch.24 micro

11. What does Clostridium difficile cause? What are the basic characteristics of this organism that help it cause disease?

Clostridium difficile is a spore-forming, Gram-positive anaerobic bacillus that produces two exotoxins: toxin A and toxin B. It is a common cause of antibiotic-associated diarrhea (AAD).You can get a fecal transplant that gives you an opportunity to grow healthy bacteria again.

9. What causes UTIs? Are men or women more susceptible to UTIs and why?

E. Coli and P. Mirabilis frequently cause urinary tract infections in women. Women frequently get UTIs due to the length of the urethra, while men have longer urethras and therefore get less UTIs. But men can still get them, mostly by the inserts of catheters.

1.Which major body sites are heavily colonized by microbes? Are you born with these microbes?

Gastrointestinal microbes are 10^13-14, skin . You are not born with microbes because you live in a sterile environment. Once you exit from the mother is when microbes will cling to you.

Lower respiratory tract

: has no normal microbiota in healthy adults [consists of trachea, bronchi,

Microbiome

: is a functional collection of different microbes in a particular environmental system

8. What is the importance of vaginal Lactobacillus in healthy adult women?

A resident organism in the vagina, ferments the glycogen, producing lactic acid [which maintains a local acidic environment].

15. How do products like beano work?

Beano is an enzyme-based dietary supplement that reduces gas in the digestive tract. It can improve digestion by reducing bloating, and discomfort.

12. What is a probiotic? How does it differ from a prebiotic? Give an example of a probiotic. What are the name of some of the genera found in a probiotic?

Probiotics are live organisms that confer a health benefit to the host. An example would be eating yogurt. Prebiotics are there for whatever is there to grow. Species of Bifidobacterium and Lactobacillus bacteria are commonly used probiotics found in yogurt and probiotic drinks.

2. What are the common genera of bacteria found on the skin, in the throat and in the intestines?

The common bacteria found on skin are Staphylococcus, Propionibacterium, and Corynebacterium. The common bacteria found in the throat are . The common bacteria found in the intestines are Firmicutes, Bacteroidetes, and Actinobacteria.

14. What causes lactose intolerance and its symptoms? What other things do fecal bacteria do?

The enzyme that splits lactose into glucose and galactose is called lactase, and it is located on the surface of the cells lining the small intestine. Lactose intolerance is caused by reduced or absent activity of lactase that prevents the splitting of lactose (lactase deficiency). If you eat any dairy products [or something containing lactose] symptoms may be diarrhea, hives, fever. The other things they make are sterol, vitamins, nutrients, etc.

13. What does it mean on a label that says "contains active culture"?

There are live bacteria in the product.

Host

is a living organism that can sustain itself within a particular environment [eukaryote or prokaryote]

Fecal Transplant

is a newer therapy for Clostridium difficile [is a spore-former and generally antibiotic resistant] infection. You get healthy fecal from a human and insert that healthy fecal to the patient through their colon [colonoscopy].

Microbiota

is a term used by scientist to describe all the microbes in a microhabitat

Upper respiratory tract

this is where microbes thrive. Bacteria continuously enter through breathing and are trapped by mucus of the nasal and oral passageways. [consists of the sinuses, nasopharynx, oropharynx, oral cavity, and larynx]

3. What parts of the body do not have normal flora bacteria?

Lower respiratory tract, sterile

10. Describe the properties of microorganisms that grow well on the skin. What determines whether or not an organism will colonize a body site?

The skins surface determines what organism will colonize on a body site by either dry, moist, or oily [sebaceous] skin. The composition is influenced by environmental factors, and host factors [puberty, personal hygiene].

Human microbiome

are about 10^13 microbes living in complex communities, functional collection of different microbes living in humans

Probiotic

are live organisms that confer a health benefit to the host. They may work by taking up space or nutrients, limiting the ability of pathogens to colonize the gut.

6. Why does eating a high sugar diet contribute to dental caries?

It is food for the bacteria to grow, these fermenters produce acid, which wear down the tooth enamel.

7. Why is the lower respiratory tract typically microbe-free?

Most bacteria get trapped in the nasal cavities

4. How does plaque form in the teeth? What type of bacteria cause dental caries? Are they aerobic or anaerobic organisms? What would you see if you did a gram stain of dental plaque?

The saliva in your mouth have lysozymes, so most of the bacteria in your mouth attach to you teeth, thus plaque. These are anaerobic and grow due to a high sugar diet. You would see a gram positive rod shaped purple stain on dental plaque.