Applied Bacterial Genetics, Sterilization and Disinfectants
Newly emerged bacterial gene causing superbugs in Europe.
Bacteria that a phage can bind to. Never all of one species, but possibly strains from more than one species or even genus
What can attach to the sex pilus of a bacteria?
Which type of phage produces a clear plaque?
Which type of phage produces a cloudy plaque?
Which experiment proved DNA as genetic material?
Hershey chase experiment.
DNA labeled with 32P, phage labeled with 35S.
32P seen in bacteria.
Destroys any DNA that is not methylated in a bacterium.
Identify strains by their susceptibility to a set of phage.
What type of genes does a conjugal plasmid carry?
What type of genes do non-conjugal plasmids carry?
How many origins of replication does a conjugal plasmid have? What are they?
Transfer origin (makes 1x DNA for transfer by conjugation)
Vegtative origin (makes 2x DNA, not related to conjugation)
When conjugal plasmids get inserted into a bacterial chromosome, this causes a piece of the bacterial chromosome to be transferred, but not generally the plasmid. Is an example of?
High Frequency Recombination (doesn't change female into male)
Bacterial Chromosome Map is calibrated in what units?
Minutes of mating
What is Cosmid Cloning?
Cosmid has plasmid replication site and a "cos" obtained from DNA phage. Causes bacteria to circularize and be packed into phage particle. Transfers big pieces of DNA.
Why arent' all bacteria males?
Phage and detergents kill males
What favors "maleness" in bacteria?
Antibiotics, Heavy metals
What is the 4th leading cause of death in the US?
The complete destruction of all living forms of life. Includes bacteria, spores, fungi, and viruses.
The use of agent to lower the number of growing microorganisms. Does not provide sterility, as spores and some viruses may survive.
An agent which lowers the count of viable microorganisms; usually applied to inanimate objects.
An agent which lowers the count of viable microorganisms; usually applied to paitients.
Critical items should be _______
Semi-critical require _________
Non-critical items require ________
Critical = sterilization
Semi-critical = high-level disinfection
Non-critical = low-level disinfection
Agents which inhibit the growth of microorganisms; upon removal of the agent, growth may resume.
Agents which kill microorganisms; upon removal of the agent, growth cannot resume.
The irreversible inability of a microorganism to reproduce.
Killing of microorganisms follows a log function when relatively high concentrations of an agent are used. What shape does the curve take at lower concentrations of agent?
Enveloped spores are most resistant to germicidal chemicals. What is least resistant?
Enveloped viruses (host cell membranes): Herpes, heptatitis, HIV
Alcohol is most active at what percent?
Agents that interfere with membrane function?
Agents that denature proteins?
Acids and alkalis
Acetone and other organic solvents
Agents that destroy or modify the functional groups of proteins.
Active ingredient in purell?
What enzyme would make the bacteria explode?
Does it require activation?
Does it irritate eyes or nose?
What pH's is it stable at?
Does it require exposure monitoring?
Does it have an odor?
Stable over a wide pH range
Has the quickest sterility time against Mycobacterium bovis?
Found in personal care and consumer products. Bacteriostatic against gram-negatives and gram positives.
Antiseptic with anti-bacterial, some anti-viral activity
Effective agent for the prevention and tx of oral disease
Adsorbs negatively charged surfaces in the mouth: prolonged antimicrobial activity
Has been used to sterilize buildings contaminated w/ anthrax spores.
Has been used to disinfect hospitals undergoing outbreaks of carbapenem-resistant Klebsiella pneumoniae
Hydrogen peroxide gas plasma
Causes single- or double- strand breaks in nucleic acids and free-radicals
Spores generally resistant
Deinococcus radiodurans is the most resistant organism known, has an efficient DNA repair process
Prions are highly resistant
What changes media color to yellow?
Most reliable method of monitoring sterilization.
Which indicator has a dye that changes according to temperature?
Which indicator has a dye that changes according to temperature and time of exposure?