1 markEDTA is a compound that reacts with metal ions to form a stable harmless compound. It is commonly used to reduce levels of calcium in many medical procedures including dental work. EDTA has also been shown to have antimicrobial properties effective in the treatment of Staphylococcus aureus bacteria.
Scientists wanted to establish how effective EDTA could be in the treatment of infections from Escherichia coli bacteria. The growth of E.coli bacteria was monitored in response to treatment with EDTA over a period of 5 days. The chart below shows the results.
State the reason for the group treated with no EDTA.
1 markCalculate the percentage difference between the number of bacteria in the sample treated with EDTA and the number of bacteria in the untreated sample after 5 days.
2 marksOutline the effect of EDTA on the growth of bacteria.
1 markThe presence of antibiotic resistance within E.coli populations was studied and presented in the graph below.
Identify which antibiotic has been shown to be the least effective against E.coli.
2 marksCompare the levels of antibiotic resistance shown in E.coli to the antibiotics studied.
3 marksThe table below shows some of the side effects associated with the antibiotics studied.
|
Antibiotic |
Side effects |
|
EDTA |
Abdominal cramps, nausea, vomiting, diarrhoea, headache, low blood pressure, skin problems and fever. |
|
Amoxicillin |
Abdominal cramps, back and leg pains, bloating, blood in urine, chest pains |
|
Tetracycline |
Nausea, vomiting, diarrhoea, loss of appetite, mouth sores, black hairy tongue, sore throat, headache |
|
Pivmecillinam hydrochloride |
Diarrhoea, feeling sick, thrush |
Using all the information provided, evaluate whether EDTA is the best candidate antibiotic to treat E.coli.
1 markSuggest a different method that could be used to help reduce the development of antibiotic resistance.
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