BMB 300 Lecture 23: Normal Microflora Lecture 1

• School: University of Maine
• Department: Micro and Molecular Biology
• Course: BMB 300
• Professor: Edward Bernard

Document Summary

Microbes regularly found at an anatomical site 1013 cell/body. Symbionts that have various interactions with host cooperation, mutualism, parasitism (pathogens) Normal microbiota at different body sites - commensals. Protective barrier - keratin: ph nacl c. inhibitory substances lysozyme d. lipids from oil glands. Streptococcus mutans- adhere via glycocalax: contribute to formation of dental plaque. Upper respiratory tract transient flora: continuous stream of mucous generated by ciliated epithelial cells - swallow microbes, lysozyme in mucus lower respiratory tract - sterile, alveolar macrophages. Gastrointestinal tract: stomach, low microbial population (10/ml) due to low ph (2-3) helicobacter pylori acute. Gastritis: small intestine low ph, bile and pancreatic secretions low population, large intestine (colon) highest [] of microbes in host 1012/g = ~1/3 dry wt fecal matter . Eliminate 3 x 1013 per day breakdown food, produce vitamins b12 and k (mutualism) . Host /parasite interaction: parasite, host compromised host primary host incidental host, infection infectious disease pathogen primary (true) pathogen opportunistic pathogen .