Different methods of classification of Bacteria
The detailed explanation of different methods of classification of Bacteria:
Morphological Classification:
- This method focuses on the physical characteristics of bacteria.
- Shape: Bacteria are classified into three main shapes: cocci (round), bacilli (rod-shaped), and spirilla (spiral-shaped).
- Size: Bacteria can vary greatly in size, from tiny cocci that are only a few micrometers in diameter to elongated bacilli that can be several micrometers long.
- Arrangement: Bacterial cells can be found in various arrangements, including singles, pairs (diplo-), chains (strepto-), clusters (staphylo-), and others.
- Additional Features: Some bacteria have unique features, such as spore formation (endospores) or appendages like flagella or pili.
Staining Reactions:
- The Gram stain is a widely used method in this category.
- Gram-Positive: Bacteria that retain the violet stain (crystal violet) and appear purple under the microscope. They have a thick peptidoglycan layer in their cell walls.
- Gram-Negative: Bacteria that take up the red counterstain (safranin) and appear pink. They have a thinner peptidoglycan layer but an outer membrane.
Metabolic Characteristics:
- This method focuses on how bacteria obtain and use energy.
- Aerobic vs. Anaerobic: Bacteria can be classified based on their oxygen requirements. Aerobic bacteria require oxygen, while anaerobic bacteria thrive in the absence of oxygen.
- Energy Sources: Bacteria can be grouped by their energy sources, such as phototrophic (using light), chemotrophic (using chemicals), or lithotrophic (using inorganic compounds).
- Fermentation: Some bacteria can ferment sugars and produce various metabolic byproducts.
Genetic Classification:
- Genetic methods have revolutionized bacterial classification.
- 16S rRNA Sequencing: The 16S ribosomal RNA gene is highly conserved in bacteria. By sequencing this gene, scientists can determine the genetic relationships between different bacterial species.
- Phylogenetic Trees: These trees illustrate the evolutionary history of bacteria, showing how different species are related.
Ecological Classification:
- Bacteria are classified based on where they are found and their ecological roles.
- Extremophiles: Bacteria that thrive in extreme environments like hot springs, acidic lakes, or deep-sea hydrothermal vents.
- Symbiotic Bacteria: These bacteria live in close association with other organisms, either as mutualists (benefitting both) or parasites (harming the host).
Serological Classification:
- This method involves the analysis of bacterial antigens and antibodies.
- Antigens: Specific molecules on the bacterial surface, such as capsular polysaccharides or flagellar proteins, are targeted.
- Antibodies: Antibodies are used to detect and classify bacteria based on their antigenic properties.
Second-Year Pharm D Subjects
| 2.1 | Pathophysiology |
| 2.2 | Pharmaceutical Microbiology |
| 2.3 | Pharmacognosy & Phytopharmaceuticals |
| 2.4 | Pharmacology-I |
| 2.5 | Community Pharmacy |
| 2.6 | Pharmacotherapeutics-I |
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