1. LECTURE 15 High GC GRAM POSITIVE BACTERIA

2. .

4. HIGH G+C GRAM POSITIVES Actinomycetes Corynebacteria Propionic acid bacteria Bifidobacteria Micrococci

5. ACTINOMYCETES: morphology & reproduction

6. Fig. 12.15. Growth of filamentous microbes (fungus or actinomycetes). Growth is from the hyphal tip. ACTINOMYCETES MORPHOLOGY

8. An actinomycete colony growing on agar - note the subterranean and aerial hyphae…. ACTINOMYCETES MORPHOLOGY

9. have filamentous growth, like fungi on substrate, grow on and in it thallus -- tissuelike mass, grown in culture mycelium -- tangled mass of hyphae, found in nature ACTINOMYCETES MORPHOLOGY IN SUMMARY:

10. ACTINOMYCETES REPRODUCTION

11. Fig. 11.19 Fig 11.19. Conidia of Streptomyces ACTINOMYCETES REPRODUCTION

12. actinomycetes (and fungi) reproduce via spores hyphal growth is followed by fragmentation and release of spores conidia – spores produced asexually on aerial filaments called sporophores shape and arrangement of sporophores help identification of actinomycete taxa ACTINOMYCETES REPRODUCTION IN SUMMARY:

13. ACTINOMYCETES: ecology

14. predominantly soil bacteria good at degrading recalcitrant compounds such as chitin & cellulose often active at higher pH (contrast to fungi who may dominate at lower pH) give soil the “earthy” smell ACTINOMYCETES ECOLOGY

15. Genus Frankia – --large genus that all form nodules on certain non-legume trees --fixes nitrogen from the air and converts into forms useable by plant host --involved in “tripartite” relationship with plant and mycorrhizal fungus. e.g. Myrica in the tropics (invasive in Hawaii) Alnus in temperate climates (early succesional) Ceanothus in USA (including gardens) ACTINOMYCETES ECOLOGY

16. Frankia nodules on Ceanothus roots

17. ACTINOMYCETES: antibiotics

18. most important genus is Streptomyces - over 500 described species! produce many important antibiotics, including Streptomycin - originally from S. griseus. ACTINOMYCETES ANTIBIOTICS

19. Other antibiotics produced by Streptomyces spp: Antibiotic:affects: SpectinomycinM. tuberculosis, N. gonorrhea NeomycinBroad spectrum, topical TetracyclinesBroad spectrum, Chlamydias, Rickettsias etc. NystatinFungi, esp. Candida ErythromycinGram + Bacteria and Legionella ChloramphenicolBroad spectrum, typhoid fever ACTINOMYCETES ANTIBIOTICS

20. Inability of a test organism to grow in the presence of Streptomyces suggests antibiotic production by the latter

21. Fig. 04.18 Fig. 4.18. Secondary metabolites are produced at the end of the growth phase and during stationary phase…. ACTINOMYCETES ANTIBIOTICS

22. TUBERCULOSIS: pathology & history

23. tubercular decay found in spinal columns of Egyptian mummies (2400BCE) Hipocrates (460BCE) described “phthisis” as most common disease of his time in 19 th century Europe 1/7 of all deaths attributed to TB afflicted famous people such as: Eleanor Roosevelt, Chopin, Checkov, Kafka, Robert Louis Stevenson, the entire Bronte family began a 19 th century literary genre: the “tragic lingering death by consumption” trophe TUBERCULOSIS PATHOLOGY & HISTORY

25. Contraction: inhaling bacteria from infected person Primary stage: bacteria isolated by granuloma in lungs called a tubercule Secondary stage: bacteria fail to be isolated, lesions form in lungs (coughing up blood) TUBERCULOSIS PATHOLOGY & HISTORY

26. tubercules (a type of granuloma) – small, hard nodules formed when macrophages surround and phagocytize M. tuberculosis TUBERCULOSIS PATHOLOGY & HISTORY

27. Fig. 23.18 Fig. 23.18. Inflammatory response forming a Tubercle. Note the lack of nuclei in dead cells in center of tubercle. TUBERCULOSIS PATHOLOGY & HISTORY

28. Before antibiotics, the only treatment was rest (to avoid secondary stage)… lead to many “Sanitaria” (Sanitariums) especially in mountainous regions with clean dry air (e.g. Boulder Mapleton Center, near Mt. Sanitas).

29. Robert Koch (remember him?) was the first to isolate Mycobacterium tuberculosis in 1882 Streptomycin was the first effective antibiotic against TB (late 1940s) a little too late for WW2. TUBERCULOSIS PATHOLOGY & HISTORY

30. Table 23.9 TUBERCULOSIS PATHOLOGY & HISTORY

31. TUBERCULOSIS: physiology

32. TUBERCULOSIS PHYSIOLOGY

33. Mycobacteria all produce mycolic acids (mycosides) - long-chain “fats” - very hydrophobic and wax-like “Slow growing” mycobacteria (such as M. tuberculosis are so hydrophobic that nutrients can’t easily diffuse in Mycolic acid is covalently bound to the peptidoglycan layer of Mycobacteria TUBERCULOSIS PHYSIOLOGY

35. You saw carbolfuchsin in the Dorner endospore stain!! Acid-alcohol fast test binds to mycolic acid. Good stain for bacteria too waxy for gram stain

36. Fig. 23.17. M. tuberculosis in sputum sample. Acid- fast stain is diagnostic for mycobacteria.

37. Virulence in M. tuberculosis associated with cord factor 2 long chain alcohol groups hooked together by a disaccharide (trehalose) Cause cultures in media to have characteristic “corded” look Cord factor is implicated as causing severe weight loss in TB patients Cord factor is also a virulence factor because it binds cells of M. tuberculosis together so that they are further resistant to our immune system TUBERCULOSIS PHYSIOLOGY

39. TUBERCULOSIS: the disease today

40. In U.S., about 10,000,000 infected individuals, many showing few symptoms 12,000 deaths in U.S. per year very common disease as part of AIDS and in the homeless population….. TUBERCULOSIS: THE DISEASE TODAY

41. Fig. 23.16 TUBERCULOSIS: THE DISEASE TODAY

43. many cases are multi-drug resistant TUBERCULOSIS: THE DISEASE TODAY

44. Many patients start feeling better after a month of antibiotic therapy and stop using antibiotics - which leads to more drug resistant bacteria. Best solution is DOTS = direct observation therapy TUBERCULOSIS: THE DISEASE TODAY

46. CORYNEFORM BACTERIA

47. name comes from “club”: some are club shaped are usually rod shaped (though stay tuned) and arranged as Vs due to snapping division

48. snapping division 2 thick peptidoglycan layers inner layer of cell wall grows inward to divide 2 new cells. As it thickens, it puts tension on outer wall until it ruptures. The snapping tears the outer wall apart except at one point which holds the 2 cells together like a hinge. CORYNEFORM BACTERIA

49. Fig. 11.14. Gram stain of a Corynebacterium - note V shapes

50. Some important genera of Coryneforms: Arthrobacter spp. common soil inhabitants rods when well fed and coccoid cells when hungry. The coccoid cells are long-lived spore- like cells. Corynebacterium spp. are common aerobic organisms of soil. One species, C. diphtheriae causes diphtheria. CORYNEFORM BACTERIA

51. Arthrobacter has a rod-coccus growth cycle In log phase, they are rods that replicate via snapping division. In stationary phase, they are coccoid. CORYNEFORM BACTERIA

52. diptheria Corynebacterium diptheriae usually spread by inhalation actual invasibility of the bacteria is minimal Produces powerful exotoxin that damages organs and causes build up of dead tissue in throat Exotoxin only produces if bacteria are infected with a certain bacteriophage (virus) and iron levels to be low 1 of 10 diptheria patients die CORYNEFORM BACTERIA

53. PROPIONIC ACID BACTERIA

54. Swiss cheese: other bacteria (e.g. lactobacilli) ferment milk’s lactose to lactic acid, form curds Propionibacteria then multiply, producing acetate, CO 2 & propionic acid PROPIONIC ACID BACTERIA

56. Fig. 06.23 Fig. 6.23 PROPIONIC ACID BACTERIA

57. Propionibacteria acnes in skin : anaerobic bacteria found in hair follicles (densities up to 10 7 per square cm of skin) growth enhanced by secretions of sebaceous glands under normal conditions, P. acnes is beneficial: creates low pH skin environment hostile to pathogens when sebaceous gland gets clogged, P. acnes multiplies in trapped sebum: ACNE! PROPIONIC ACID BACTERIA

58. happy hair follicle PROPIONIC ACID BACTERIA

59. BIFIDOBACTERIUM

60. Bifidobacterium bifidus anaerobic ferments a specific amino sugar and lactulose (a disaccharide consisting of fructose and galactose) found in breast milk breast milk also contains bifidus factor, an oligosaccharide that specifically promotes bifidus colonization one of the initial colonists of the intestines of human babies also added to yogurt…. BIFIDOBACTERIUM

61. Fig. 11.12 MICROCOCCUS

62. oligate aerobic cocci Have high %GC but morphologically dissimilar to the rest of the high GC gram + bacteria usually yellow, orange, or red in color