- •Describe how to prepare a wet mount slide «The crushed drop» from liquid and agar microbic cultures.
- •1. Obtain a clean microscope slide.
- •What is the main technology of preparing the stains for determination of the morphology of microorganisms. What are the sizes and main shapes of the bacteria?
- •What kind of dye is used in microbiology? Name the methods of staining.
- •Types of Dyes
- •Ziehl-Neelsen Stain
- •India Ink
- •Methylene Blue Stain
- •Sketch a picture of the microorganism.
- •Sign the picture and specify Total Magnification (tm).
- •Gram Stain
- •4)What is the reason of using Gram staining? Describe this method of staining.
- •How Gram negative and Gram positive bacteria are looked like after Gram staining? Explain it.
- •How to distangushing Gram positive and Gram negative bacteria if you don’t have dyes and microscope? Describe this method and explain it.
- •Period 1
- •Period 2
- •What are the differences between slimy layer and capsule of bacteria? Capsules are considered protective structures. Various functions have been attributed to capsules including: ….
- •Biofilms – strategy of a survival of bacteria in environment. Characterize structure of biofilms. Explain the increased resistance of bacteria in biofilms.
- •Background
- •Results
- •Conclusion
- •Characterize spirochete. What features of their morphology and structure of cells. The habitat and representatives.
- •Classification
- •Spirochetes
- •12. Describe the methods Endospore (Spore) staining. Ozheshko method.
- •Explain the high resistance of bacterial endospores to unfavorable factors.
- •Characterize anaerobic spiral Gram- bacterium. What features of their morphology and structure of cells. The habitat and representatives.
- •Characterize sliding bacteria. What features of their morphology and structure of cells. The habitat and representatives.
- •Characterize budding bacteria. What features of their morphology and structure of cells. The habitat and representatives.
- •Characterize mycobacteria and nokardia forms. What features of their morphology and structure of cells. The habitat and representatives.
- •Characterize actinomycetes. What features of their morphology and structure of cells. The habitat and representatives.
- •What are the molecular and structural differences between archaea and eubacteria? Give a detailed response.
- •Bacterial Genome is consisted from 2 subsystems. Name and describe them. What properties of the cells are carried by plasmids.
- •Describe the internal structures of prokaryotic cell. Cytosol and Cytoplasm. Nonmembranous organelles: Ribosomes, Mesosomes. Nucleoid.
- •Bacteria can form specialized, morphologically differentiated structures. Describe them.
- •1. High molecular weight dna must bind to the cell surface.
- •2. The bound dna is taken up through the cell membrane.
- •3. The donor dna fragment is then integrated into the host chromosome or replicates autonomously as a plasmid.
- •Unlike eukaryote no true sexual reproduction is found in bacteria because: …. What are the features of the bacterial recombination
- •What are the functions of homologous associations of bacteria? Provide examples of homologous associations of bacteria.
- •Biochemical Tests: Microbiologists also use biochemical tests, noting a particular microbe's ability to utilize or produce certain chemicals.
- •What do the terms: pure culture, species, strain, clone in microbiology? What are the differential characteristics of the species?
- •What classification systems of microorganisms were offered before? Presents the modern classification system.
Background
Microbial biofilms represent an incompletely understood, but fundamental mode of bacterial growth. These sessile communities typically consist of stratified, morphologically-distinct layers of extracellular material, where numerous metabolic processes occur simultaneously in close proximity. Limited reports on environmental isolates have revealed highly ordered, three-dimensional organization of the extracellular matrix, which may hold important implications for biofilm physiology in vivo.
Results
A Pseudomonas spp. isolated from a natural soil environment produced flocculent, nonmucoidal biofilms in vitro with unique structural features. These mature biofilms were made up of numerous viable bacteria, even after extended culture, and contained up to 50% of proteins and accumulated 3% (by dry weight) calcium, suggesting an important role for the divalent metal in biofilm formation. Ultrastructurally, the mature biofilms contained structural motifs consisting of dense, fibrillary clusters, nanofibers, and ordered, honeycomb-like chambers enveloped in thin sheets.
Conclusion
Mature biofilms contained living bacteria and were structurally, chemically, and physiologically heterogeneous. The principal architectural elements observed by electron microscopy may represent useful morphological clues for identifying bacterial biofilms in vivo. The complexity and reproducibility of the structural motifs observed in bacterial biofilms appear to be the result of organized assembly, suggesting that this environmental isolate may possess ecological advantages in its natural habitat.
Characterize spirochete. What features of their morphology and structure of cells. The habitat and representatives.
Spirochaetes (also spelled spirochetes) belong to a phylum of distinctive diderm (double-membrane) bacteria, most of which have long, helically coiled (spiral-shaped) cells. Spirochaetes are chemoheterotrophic in nature, with lengths between 5 and 250 µm and diameters around 0.1–0.6 µm.
Spirochaetes are distinguished from other bacterial phyla by the location of their flagella, sometimes called axial filaments, which run lengthwise between the bacterial inner membrane and outer membrane in periplasmic space. These cause a twisting motion which allows the spirochaete to move about. When reproducing, a spirochaete will undergo asexual transverse binary fission.
Most spirochaetes are free-living and anaerobic, but there are numerous exceptions.
Classification
The spirochaetes are divided into three families (Brachyspiraceae, Leptospiraceae, and Spirochaetaceae), all placed within a single order (Spirochaetales). Disease-causing members of this phylum include the following:
Leptospira species, which causes leptospirosis[2]
Borrelia burgdorferi, B. garinii, and B. afzelii, which cause Lyme disease
Borrelia recurrentis, which causes relapsing fever[3]
Treponema pallidum subspecies which cause treponematoses such as syphilis and yaws.
Brachyspira pilosicoli and Brachyspira aalborgi, which cause intestinal spirochaetosis[4]
Cavalier-Smith has postulated that the Spirochaetes belong in a larger clade called Gracilicutes