Lactobacillus Acidophilus

Question 1

Lactobacillus genus morphology, culture, and habitat

Answer 1

Gram positive rod

20% of the population is anaerobic

Culture:

Must be anaerobic.

Grown on selective Rogosa agar medium, which is adjusted to have a low pH, contains yeast extract and peptone.

Colonies are shiny and white and smell like yogurt

Normaflora of the oral cavity, GI, and vagina.

Question 2

What is a Probiotic vs. a Pre-biotic

Answer 2

Probiotic: something that contains live microorganisms that can be administered for a health benefit. Examples: Lactobacillus and Bifidobacterium

Prebiotic: nondigestible food ingredients that stiumlate the normal flora that are already in the GI tract.

Question 3

What Lactobacillus species are present in the vagina and oral cavity? What do they secrete?

Answer 3

• L. acidophilus,*
• L. Casei, and*
• L. Fermentum*

Produces lactic acid,

Damages enamel and is involved in caries, and also produces the lower pH of the vagina that is protective against other infections.

Question 4

Bifidobacterium genus morphology and habitat

Answer 4

Gram positive rod

Lactic acid producing

Found in the GI of breast-fed babies

Used as a pro-biotic for the vagina or GI.

Question 5

What are the pathologies caused by Lactobacillus species?

Answer 5

Most commonly: Dental Caries, enamel damage from lactic acid

Rarely: Endocarditis if the immune system is weak and the oral hygeine is poor

Opportunistically: Septicemia in immunocompromised patients.

Question 6

Describe the 3 stages/grades of vaginal flora from a vaginal smear

Answer 6

1) normal epithelial cells and only primarily lactobacillin present
2) mild infection with other G+ and G- bacteria but with lactobacillin present
3) no lactobacillin, and strong infection with lots of G+ and G- bacteria