Microbial nutrition and growth
True or False:
Bacteria which can withstand high osmotic pressure are known as barophiles.
False
What are the methods of horizontal gene transfer?
1. transduction
2. transformation
3. conjugation
The use of physical or chemical means to kill most, if not all, pathogenic microbes on inanimate object.
disinfection
The motile feeding stage of a protozoan is known as a(n)...?
Trophozoite
Pseudomonas aeruginosa is a encapsulated, Gram-negative, aerobic–facultatively anaerobic, mesophilic bacteria. This microorganism is one of the most frequent and severe causes of hospital-acquired infections, particularly affecting immunocompromised and ICU patients. What is the optimal growth temperature of Pseudomonas aeruginosa?
37 degrees Celcius
Escherichia coli shares its DNA with other E. Coli in the area via direct contact and a pilus, what is a necessary component of the donor E. Coil for conjugation to happen?
F-factor
90% of my colony dies in the first minute, and 90% of the remaining colony dies in the next minute, this pattern continues exponentially. What is this description of and why is it important
decimal reduction time. It is important to know for the use of antimicrobials in the environment and how long they need to be applied.
This antibiotic blocks the transport of NAM and NAG molecules from the cytoplasm. What antibiotic am I?
Bacitracin
Which form of the Plasmodium parasite infects liver cells?
Sporozoites
The genus Halobacterium is a family of archaea that can be found in places like the Great Salt Lake and the Dead Sea. These organisms require an environment of high-salt concentration as many of their proteins will not function in low-salt environments. Halobacterium also grows best in a 42 °C environment. How would you classify Halobacterium based on its response to different salt concentrations?
Obligate halophile
Bacillus subtilis is a gram+ bacterium that is commonly found in soil. it is widely studied for its natural competence. If a cell nearby undergoes lysis and releases its DNA into the surrounding environment. Bacillus subtilis might take up the released DNA and integrate some genes into its genome. As the Bacillus cells divide, the acquired trait gets passed onto its descendants. This is an example of what mode of horizontal gene transfer.
transformation
While in the lab, you are sterilizing your media plates. you place them in the autoclave and turn it on. After 10 minutes the power in the building and the autoclave shuts down. What form(s) of bacteria would still be living on the plate?
bacterial endospores
This group of antibiotics attach to the A-site of a ribosome, causing them to interfere with the attachment of tRNA to mRNA. They are also considered to be one of the broadest spectrums of antibiotics. Which class of antibiotics am I?
Tetracyclines
As trophozoites are for _____, vegetative cells are for endospores.
cysts(inactive)
Mycobacterium tuberculosis lies dormant in tubercles without oxygen. When these tubercules rupture the bacteria are exposed to oxygen and multiply rapidly. Mycobacterium tuberculosis is most likely a(n)?
Obligate aerobe
This kind of plasmid is responsible for a bacterium’s ability to create a pilus
fertility factor
Acne can be caused by an overgrowth of the bacteria cutibacterium acnes on the face. Benzoyl peroxide is often a common treatment for this bacterium, it works by traveling deeper into the layers of the skin to dissolve the build-up of sebum and infuses the pores with oxygen, destroying the airless environment where C. acnes thrive. Benzoyl peroxide takes electrons from the bacteria and benzoyl peroxide becomes reduced in the process. What type of major chemical control category does benzoyl peroxide fall into?
Oxidizing agents
This class of antibiotics that bind to an enzyme that is involved in the synthesis of folate, which is essential for the production of DNA and RNA in bacteria.
Sulfonamides
Vaginal candidiasis is caused by an overgrowth of Candida albicans. What are some factors that contribute to the overgrowth of Candida?
Vaginal pH becomes more alkaline(7-14)
Normal bacterial populations, particularly Lactobacillus, are reduced by antibiotics
Biofilms contribute to medical device-related infections. What is the term for bacteria's ability to communicate to exhibit coordinated behavior among other bacteria that helps them become more resistant to various agents?
Quorum sensing
When tryptophane is present in the environment it causes the trpR protein to bind to the operator, blocking the transcription of the trp operon by RNA polymerase. thus preventing the synthesis of tryptophan from its precursor. when tryptophan is not present, the repressor is in its inactive form and can not bind to the operator region, so transcription is not inhibited by the repressor. What type of operator is this?
repressible operon
1% silver nitrate used to be applied to the eyes of newborns to prevent blindness caused by Neisseria gonorrhoeae. Erythromycin is now used instead in clinical practice. Silver nitrate is an example of which method of microbial growth control? (Be specific!)
Heavy Metals
Pleconaril and Arildone are both antiviral drugs. Describe their mechanisms of action and how they differ in targeting viral infections.
Pleconaril blocks viral attachment while Arildone prevents viral uncoating.