Each of the two threadlike strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of DNA.
Answer:
You are interested in obtaining Staphylococcus aureus for a study investigating the prevalence of methicillin-resistant Staphylococcus aureus in the general population. You have received several samples and are ready to start your isolation procedures. Describe the personal protective equipment that would be needed and three different culturing techniques that can be used to obtain organisms to produce pure cultures. State if you use general or selective media and which specific media you would choose. How would you determine if the culture was contaminated? What is the first step you would take if you detected contamination?
Personal Protective equipment needed; No special precautions are necessary when working with methicillin-resistant staphylococcus aureus, staphylococcus aureus is a bio-safety level
Three different culturing media; to include;
- Etest Method
- Disc Diffusion
- Latex Agglutination.
Properly enriched selective media is used.
The most accurate method for identifying Merthicillin-resistant staphylococcus is to test for the presence of mecA gene by PCR.
The best specific media is latex agglutination test and oxacillin salt agar screen.
How to determine if the culture was contaminated;
It can be spotted by the turbidity of the growth medium or the floating branching mycelia, bacteria contamination can be detected under 10× microscope within few days of contamination.
Step to take if contamination is detected;
Biological contamination is a serious issue and being able to correctly identify different types of contamination is an essential first step in ensuring the safety of your culture.
Explanation:
The literature on methicillin susceptible testing is extensive, and often conflicting in recommendations regarding the most important method for routine use. this is partly because the various studies of phenotypic methods have included different strains, which may differ significantly in heterogeneity and behave differently under particular test condition.
The process is called Exocytosis.
A special hint for ease:
EXO → Out
ENDO → In
The answer is: emigrate.
An emigration is a movement of organisms from the region of settle. So, when organisms leave a population, they emigrate.
An immigration is the opposite process of the emigration in which organism move to some area. <span>Competition is an interaction between members of the same species or between different species in which they compete for resources. Reproduction is a process of production of new organisms.</span>