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Control of microbial growth 1 - Coggle Diagram
Control of microbial growth 1
Physical methods of control
HEAT
autoclave- moist heat for bactericidal
Preffered method of sterilization, provided the material will not be damaged by heat or moisture
Used to sterilize media
Dry Heat- bacteriocidal
flame
Medical waste incinerator
bactecinerator
pasteurization- bactericidal
pasteur used mild heat to kill spoilage organisms without changing the taste of the wine
used now for milk and milk products
72 C for 15 seconds, kills pathogens in milk and lowers bacteria number does NOT sterilize it
Filtration
Fast, filters have holes of 0.2 microns, applicable to clear liquids and gasses only, HEPA filters 0.3 microns
Low temps- Listeriosis, one of the few pathogens that like to grow at refrigerator temp, serious in pregnant women found commonly in deli meat
Osmotic pressure- sakt or sugar along with smoking were used to curate meats, used in dehydration of fruit and meat
Radiation
UV light- 260 nm damages DNA by producing thymine dyers, does not penetrate the cell wall, an damage out eyes, skin and cause burns
Ionizing Rays- Gamma and X-ray- short wave length but have high energy electron beam, destroys bacterial DNA, food industry, catheters, plastics
Types of drugs
Antiretroviral- influenza treatment, HIV infection treatments, Genital herpes treatment
Disinfectants
Phenol- lysol bispheonol- triclosan found in many soaps and plastics
Zephiran- used in mediations to treat acne
Cepacol- widely used in mouthwash
Eukaryotic cells, have points of selectivity are fewer than antibacterial, fungi are opportunistic, polyenes- amphotericin B- TMT of systemic fungi. Azoles- imidazole- OTC TMT cantankerous mycoses
Multiplication of bacteriophages
lytic- bacteria infect and take over the replication process. the end of the cycle results in the death of the host
lysogenic- part of transduction mechanism, can acquire new genetic information. use be through a template virus, host cell remains alive just gains new properties from the virus.
at the end there is a phage conversion so the host cell may have new properties, Corynebacterium diphtheria, produces the disease diphtheria when a prophage is present, Prophage codes for the cytotoxin
Herpes is a latent infection, it stays dormant. But there are some environmental triggers that can make the virus go back to active
chicken pox is another example of this, as you age your immune system decreases and so it goes and resestablishes the infection as shingles.
Biosyntehsis- DNA replication occurs in the nucleus of host cell, capsid and protein synthesis are synthesized in cytokines then transported to nucleus. the exception I the POX virus, it is too large it remains in the cytoplasm
RNA Virus- reverse transcription, uses the viral RNA as a template to produce a complimentary double strand where they then go and make the protein.