micro section 3

• Foods preserved by canning often become contaminated with C. botulinum. This produces a neurotoxin call botulism. it produces endospores that can survive harsh conditions
• Biological safety level 1 (bsl-1) is the lowest level of protection. It does not cause infection to healthy human cells .it is okay to use normal hand washing techniques while dealing with this level bacteria . Ex ecoli or B.subtilis
• Biological safety level 2 (bsl-2) poses moderate risk of exposure to infectious agents to workers .Bacteria such as salmonella, or viruses like hepatitis will require PPE, dispensed air and an eyewash station
• Biological safety level 3(bsl-3) is lethal by inhalation . There are exotic pathogens like B.anthracis , HIV and M.tuberculosis. It has restricted access to the lab, vaccinations are needed for every worker.
• Biological safety level (bsl-4) is the most dangerous and often fatal. Often times theres are no vaccine for these pathogens . ex, ebola an small pox . most workers have to change into a portective suit and central air is given to prevent spread
• Chemicals that can be used to achieve sterilization are call sterilants . They kill all microbes, viruses , and endospores
• What is a designated area that is kept free of all vegetative microbes ,endospores and viruses called?

  Sterile field
• commercial sterilization 


  uses heat at a temp low enough to preserve food quality but high enough to destroy pathogens like c.botulinum
• What is an example of a natural disinfectant that is used to kill most microbes and has acidity to it ?

  vinegar
• Chemical disinfectant like bleach are used mostly to kill non-living surfaces like bathrooms or sinks
• Critical items such as surgical instrument , catheters and intravenous fluids must be sterile because they are used inside the body
• Handwashing 


  is an example of degerming , microbial numbers are reduced by gently scrubbing the skin with soap
• • Bactericides kill bacteria
  • Viricides kill on inactivate viruses
  • Fungicides kill fungi
• • Bacteriostatic treatments inhibit the growth of bacteria
  • Fungistatic treatments inhibits the growth of fungi
• -static treatment do not kill infectious agents and they are less toxic to human . thy prevent a pathogen from multiplying.
• What is used in simple techniques like cooking and canning .

  Heat
• heat can kill microbes by altering their microbes and denaturing proteins
• What is the lowest temp point that a microbes can be kill within a 10 minute exposure ?

  Thermal death point (tdp)
• Which method is effective at killing vegetative cells and some viruses

  boiling
• What moist heat sterilization, sterlize items like surgical equipment from vegetative cell, viruses, and endospores without damaging the items?

  Autoclave
• high temp short time pasterization lowers bacterial number in milk while maintaining the quality
• Pascalization 


  uses high pressure processing that kill bacteria, yeasts and molds. it is sufficient to kill vegetative cells by protein denaturation
• high o2 concentration enhances the body's immune responses by increasing the activiity of white blood cells that fight infections
• What method is used to preserve foods like raisans and jerky ?

  desiccation (dehydration )
• Lyophilization is used for food preservation . it freeze drys food
• Ionizing radiation such as x-rays and gamma rays alter the molecular of DNA and damages cell components . eventually leading to the cell death
• Membrane filtration

  is used to remove microbes from liquid samples such as antibiotic solutions . Their filter pore size is 0.2Um
• heavy metal kill microbes by binding proteins inhibiting enzymatic activity .heavy metals are bioaccumulate in humans and animal . Meaning an excessive amount can have toxic affect on humans
• mercury can treat syphills. Compounds like m. chloride are bacteriostatic and have a broad-spectrum activity .
• What is a group of strong , broad spectrum disinfectant and biocide that has the ability to kill bacteria ,viruses ,fungi and replaces a hyrdogen atom

  Alkylating agent (formaldehyde)
• What is added to process meats to maintain color and stop the germination of c.botulinum endospores ?

  nitrites
• What prevents browning of foods and is used for the preservation of dried fruits

  sulfur dioxide
• what is used in either liquid form or as a vapor for sterilization medical instruments and tissue grafts

  b-propinolactone(kills endospores )
• Hydrogen peroxide (peroxygens ) is commonly used as a disinfectant. Gaseous perioxde has greater efficacy and can be used as a sterilant for rooms
• Phenols are used as disinfectants and antiseptics.
• What class disrupts membranes and denatures proteins

  alchols
• Bactericidal drugs kills their target bacteria
• Bacteriostatic drugs cause a reversible inhibition of growth , with bacterial growth restarting once the drug is removed
• Which of the following selectively kills or inhibits the growth of microbial targets while causing minimal to no harm to the host

  Selective toxicity
• Antibacterials that target cell wall biosynthesis are bactericidal in their actions