C hair of M icrobiology, V irology, and I mmunology

1. SIGNIFICANCE OF MICROBIOLOGY IN PRACTICAL ACTIVITY OF DOCTORS. THE HISTORY OF MICROBIOLOGY. CLASSIFICATION AND STRUCTURE OF MICROORGANISMS. Chair of Microbiology, Virology, and Immunology

2. Lecture schedule • History of Microbiology. • Classification of bacteria. • Structure of bacterialcell

3. Microbiology is a science, which study most shallow living creatures - microorganisms. Before inventing of microscope humanity was in dark about their existence. But during the centuries people could make use of processes vital activity of microbes for its needs. They could prepare a koumiss, alcohol, wine, vinegar, bread, and other products. During many centuries the nature of fermentations remained incomprehensible.

4. Brueghel: The Triumph of Death (1560)

5. Microbiology learns morphology, physiology, genetics and microorganisms systematization, their ecology and the other life forms. • Specific Classes of Microorganisms • Algae • Protozoa • Fungi (yeasts and molds) • Bacteria • Rickettsiae • Viruses • Prions

6. The Microorganisms are extraordinarily widely spread in nature. They literally ubiquitous forward us from birth to our death. Daily, hourly we eat up thousands and thousands of microbes together with air, water, food. On our skin, in mouth and nasal cavities, on mucous membranes and in bowels enormous amount of microorganisms live and act. Many of them are found in earth cortex and in the air, and in the ocean’s, sea’s, river’s water, on all of latitudes, mainlands and continents.

7. For the first time term “microbe" was offered by French scientist Sh. Sedillot in 1878. It derives from Greek “microbe", that means briefly living, or most shallow living creature. Science, which learns the microorganisms, was named by E. Duclaux microbiology. For short development period this science accumulated great factual material. The separate microbiological branches such as bacteriology, mycology, protistology, virology quickly appeared.

8. Comparative sizes of Bacteria

9. Periods of microbiology development • Morphologic • Physiologic • Prophylactic

10. Development of microbiological science was interlinked with art of glass and diamonds grinding. This brought to creation of the first microscope by Hans and Zacharian Jansen in Holland in 1590. The discovery of microorganisms is associated with the name of Antony van Leeuwenhoek (1632-1723).

11. In 1683 Leeuwenhoek described the basic bacterium forms. His scientific supervisions Leeuwenhoek described in special letters and sent off them to the London Royal Scientific Society. He sent away about 300 letters. The Leeuwenhoek’s letters brought on enormous surprise among English scientists. They opened a fantastic world of invisible creatures. He named them “living animals" (animalcula viva) and in one of letter wrote: “In my mouth there are more animacula viva, than peoples in all United Kingdom".

12. These wonderful discovery of Dutch naturalist were the embryo, with which science of bacteria developed. Namely from these times starts the so-called morphological period in microbiology history (XVII middle of age). It is also called micrographycal period, as the study of microorganism came only to description of their dimensions and forms. Biological properties and their significances for man still a long time remained incomprehensible.

13. However, using the primitive microscopes of that time it was difficult to determine the difference between separate bacteria species. Even celebrated founder of scientific systematization of all of living organisms Karl Linney renounced to classify the bacteria. He gave them general name “chaos".

15. In the second half of XIX century microbiology strongly affirms as independent science. Namely these sciences were fruitful soil, onwhich Pasteur's talent evinced. He studied wine "illness“, fermentation, made Pasteurization method,offered to grow microbes on artificial nutrient media, he proved, that on definite cultivation conditions the pathogenic bacteria lose its virulence, made vaccine against anthrax, rabies. Physiological period has began

17. Not less important are scientific works of celebrated German scientist R. Koch. He performed classic researches on etiology of anthrax, opened tuberculosis bacilli, cholera vibrio, proposed to isolate pure bacterial cultures on solid nutrient media (gelatin, potatoes), developed the preparations staining methods by aniline dye-stuffs, method of hanging drop for examination of bacteria motility, offered apparatus for sterilization

18. The Patriarch of world and Ukrainian microbiology - I. Metchnikov He studied inflammation pathology, phagocytosis, bases about antagonism of bacteria. From all microbes-antagonists I.Metchnikovpreferred the lactic bacteria. On their base he offered three medical preparations -sour clotted milk, yogurt and lactobacillin. Now they are called by eubiotics. Classic Metchnikov's researches defined a prophylactic period inmicrobiology history.

19. In 1892 D. Ivanovskiy described an virus of mosaic tobaccoillness – new class of infectious agents

20. Microorganisms constitute a very antique group of living organisms which appeared on the Earth's surface almost 3000 million years ago.

21. There are natural and artificial classifications system. Bergey's Manual of Determinative Bacteriology - the "bible" of bacterial taxonomy.

22. Classifying Bacteria • Bergey’s Manual of Systematic Bacteriology • Classifies bacteria via evolutionary or genetic relationships. • Bergey’s Manual of Determinative Bacteriology • Classifies bacteria by cell wall composition, morphology, biochemical tests, differential staining, etc.

23. Idea: Whitaker – five kingdoms (1969)

24. The Three-Domain System Prokaryotes Idea: Woese- domains (1978) Figure 10.1

25. Comparison of the three domains

26. Prokaryotes

29. Classification Systems in the Procaryotae • Microscopic morphology • Macroscopic morphology – colony appearance • Physiological / biochemical characteristics • Chemical analysis • Serological analysis • Genetic and molecular analysis • G + C base composition • DNA analysis using genetic probes • Nucleic acid sequencing and rRNA analysis

30. Bacterial Taxonomy Based on Bergey’s Manual • Bergey’s Manual of Determinative Bacteriology – five volume resource covering all known procaryotes • classification based on genetic information –phylogenetic • two domains: Archaea and Bacteria • five major subgroups with 25 different phyla

31. Taxonomy • Domain • Kingdom • Phylum • Class • Order • Family • Genus • species

32. Major Taxonomic Groups of Bacteria • Vol 1A: Domain Archaea • primitive, adapted to extreme habitats and modes of nutrition • Vol 1B: Domain Bacteria • Vol 2-5: • Phylum Proteobacteria – Gram-negative cell walls • Phylum Firmicutes – mainly Gram-positive with low G + C content • Phylum Actinobacteria – Gram-positive with high G + C content

33. Microbial Phylogeny • Phylogeny of domain Bacteria • The 2nd edition of Bergey’s Manual of Systematic Bacteriology divides domain Bacteriainto 23 phyla.

34. Microbial Phylogeny • Phylogeny of domain Bacteria (cont.) • Phylum Proteobacteria • The largest group of gram-negative bacteria • Extremely complex group, with over 400 genera and 1300 named species • All major nutritional types are represented: phototrophy, heterotrophy, and several types of chemolithotrophy • Sometimes called the “purple bacteria,” although very few are purple; the term refers to a hypothetical purple photosynthetic bacterium from which the group is believed to have evolved

35. Microbial Phylogeny • Phylogeny of domain Bacteria (cont.) • Phylum Proteobacteria (cont.) • Divided into 5 classes: Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria, Epsilonproteobacteria

36. Microbial Phylogeny • Phylogeny of domain Bacteria (cont.) • Phylum Proteobacteria (cont.) • Significant groups and genera include: • The family Enterobacteriaceae, the “gram-negative enteric bacteria,” which includes genera Escherichia, Proteus, Enterobacter, Klebsiella, Salmonella, Shigella, Serratia, and others • The family Pseudomonadaceae, which includes genus Pseudomonas and related genera • Other medically important Proteobacteria include genera Haemophilus, Vibrio, Camphylobacter, Helicobacter, Rickessia, Brucella

37. Microbial Phylogeny • Phylogeny of domain Bacteria (cont.) • Phylum Firmicutes • “Low G + C gram-positive” bacteria • Divided into 3 classes • Class I – Clostridia; includes genera Clostridium and Desulfotomaculatum, and others • Class II – Mollicutes; bacteria in this class cannot make peptidoglycan and lack cell walls; includes genera Mycoplasma, Ureaplasma, and others • Class III – Bacilli; includes genera Bacillus, Lactobacillus, Streptococcus, Lactococcus, Geobacillus, Enterococcus, Listeria, Staphylococcus, and others

38. Microbial Phylogeny • Phylogeny of domain Bacteria (cont.) • Phylum Actinobacteria • “High G + C gram-positive” bacteria • Includes genera Actinomyces, Streptomyces, Corynebacterium, Micrococcus, Mycobacterium, Propionibacterium • Phylum Chlamidiae • Small phylum containing the genus Chlamydia

39. Microbial Phylogeny • Phylogeny of domain Bacteria (cont.) • Phylum Spirochaetes • The spirochaetes • Characterized by flexible, helical cells with a modified outer membrane (the outer sheath) and modified flagella (axial filaments) located within the outer sheath • Important pathogenic genera include Treponema, Borrelia, and Leptospira • Phylum Bacteroidetes • Includes genera Bacteroides,Flavobacterium, Flexibacter, and Cytophyga; Flexibacter and Cytophyga are motile by means of “gliding motility”

40. Procaryotae Kingdom has 4 Divisions according to the structure of cell wall and Gram staining: Gracilicutes (gracilis - thin, cutis - skin) – Gram-negative bacteria, Firmicutes (firmus - firm) – Gram-positive bacteria, Tenericutes (tener – soft, tender) – microbes without cell wall, Mendosicutes (mendosus - mistaket) – microbes with atipical peptidoglican

41. Bacterial Nomenclature • Binomial naming system • Two word naming system • First word is genus name • Always capitalized • Escherichia • Second word is species name • Not capitalized • coli • When writing full name genus usually abbreviated • E. coli • Full name always italicized • Or underlined

42. Species is population of microbes, which have the only source of origin, common genotype, and during the present stage of evolution are characterized by similar morphological, biochemical, physiological and other signs

43. If deviations from the typical species properties are found on examination of the isolated bacteria, then culture is considered a subspecies. Infrasubspecies subdivisions serovar (antigenic properties) morphovar (morphological properties) chemovar (chemical properties) biovar (biochemical or physiological properties) pathovar (pathogenic properties) phagovar (relation to phages)

44. The term clonewas applied to population of cells derived from a single cell Population is an elementary evolutional unit (structure) of a definite species The term strain designates a microbial culture obtained from the different sources or from one source but in different time Or: A subgroup within a species with one or more haracteristics that distinguish it from other subgroups in the species

45. Bacteria (Gk. bakterion - small staff) are unicellular organisms lacking chlorophyll. Morphological Classification of Bacteria Morphologically, bacteria possess four main forms: • spherical (cocci) • rod-shaped (bacteria, bacilli, and clostridia) • spiral-shaped (vibrios, spirilla and spirochaetes) • thread-shaped(non-pathogenic)

47. Coccus Tetrad Diplococcus Sarcinae Streptococcus Staphylococcus Cocci groupings

48. Cocci (Gk. kokkos berry). These forms of bacteria are spherical, ellipsoidal, bean-shaped, and lanceolate. Cocci are subdivided into six groups according to cell arrangement, cell division and biological properties Micrococci (Micrococcus). The cells are arranged singly or irregularly. They are saprophytes, and live in water and in air ( M. roseus, M. luteus, etc.).

49. Diplococci (Gk. diplos double) divide in one plane and remain attached in pairs. These include: Meningococcus (causative agent of epidemic cerebrospinal meningitis, and gonococcus, causative agent of gonorrhoea and blennorrhoea) Pneumococcus (causative agents of pneumonia)

50. Streptococci (Gk. streptos curved, kokkos berry) divide in one plane and are arranged in chains of different length. Some streptococci are pathogenic for humans and are responsible for various diseases.