Bacteria Culturing : Fundamentals and Uses

By: Sree Marella

Bacteria are living organisms found everywhere in the world and inside us. Though most bacteria is harmless, some harmful bacteria (also called pathogens) can cause infections. In order to study the identity of these infectious organisms, immunologists and microbiologists grow these bacterial cells on a culture medium, usually an agar gel plate, under certain supervised laboratory conditions. They grow multiple colonies of the cells in order to examine physical characteristics, compare the patient samples with a sample of another pre-identified bacterial colony, and analyze if the infection-causing bacteria (of the patient) is the same as the pre-identified bacterial colony. Some characteristics of colonies that can be used to identify the bacteria include shape, color, or size. For example, common forms seen include circular, irregular, or filamentous, and these vary between each type of bacterial species. Regular infectious diseases caused by bacteria are strep throat (caused by Streptococcal bacteria), Pneumonia (Streptococcus pneumoniae), Tuberculosis (Mycobacterium tuberculosis), and Meningitis (Meningococcus). By using the technique of bacteria culturing, scientists can identify the infectious pathogens, which allows immunologists to treat the infection with the correct antibiotics. Antibiotics make it harder for bacteria to reproduce, and many antibiotics fight infections by destroying the bacterial cell wall of the pathogens. In the real world today, many microbiologists are analyzing bacterial infections and the characteristics of the pathogens, which allows immunologists to create antibiotics that target pathogenic microorganisms.