INFECTIOUS AGENTS - Antibiotic Resistance

Question 1

What are the four mechanisms of antibiotic resistance?

Answer 1

Innate resistance
Mutation
Phenotypic adaptation
Acquisition of antibiotic resistance genes

Question 2

What are the four types of antibiotic resistance genes?

Answer 2

Inactivation of antibiotic
Active efflux of antibiotic
Alteration of target sights
Metabolic bypass

Question 3

Why are Gram negative bacteria intrinsically more antibiotic resistant than Gram positive bacteria?

Answer 3

Gram negative bacteria have an outer membrane which prevents the penetration of many antibiotics

Question 4

What are the two methods of antibiotic inactivation by bacteria?

Answer 4

Hydrolysis
Chemical modification

Question 5

Give an example of a Hydrolysis mechanism of antibiotic resistance

Answer 5

The production of β-lactamase by bacteria to inactivate β-lactam antibiotics

Question 6

What can be used to overcome β-lactamase enzymes produced by bacteria?

Answer 6

β-lactamase resistant β-lactams
β-lactamase inhibitors

Question 7

Give an example of a β-lactamase resistant β-lactam

Answer 7

Methicillin

Question 8

Give an example of a β-lactamase inhibitor

Answer 8

Clavulanic acid

Question 9

Give two examples of β-lactamases that β-lactamase resistant β-lactams and β-lactamase inhibitors are ineffective against

Answer 9

Carbapentamases
Extended-Spectrum-Beta-Lactamase (ESBL)

Question 10

What is the active efflux of antibiotics?

Answer 10

Efflux pumps present on the cytoplasmic membrane of bacteria actively pump out antibiotics from the bacterial cytoplasm

Question 11

How has Methicillin Resistant Staphylococcus aureus (MRSA) become resistant to β-lactams?

Answer 11

Methicillin Resistant Staphylococcus aureus (MRSA) acquired a MecA gene from another organism which codes for an alternated penicillin binding protein (PBP) making MRSA resistant to β-lactams

Question 12

How have bacteria used metabolic bypass to gain resistance against trimethoprim and sulphonamides?

Answer 12

Bacteria have acquired genes which produce alternate forms of dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) reducing the bacterial affinity for trimethoprim and sulphonamide antibiotics

Question 13

What has caused the massive evolution of antibiotic resistance?

Answer 13

The irresponsible use of antibiotics in agriculture, medicine and veterinary medicine

Question 14

Give an example of inappropriate use of antibiotics in agriculture

Answer 14

The use of antibiotics as growth promoters in livestock

Question 15

(T/F) 2/3 of worldwide antibiotics are used in agriculture

Answer 15

TRUE

Question 16

How are antibiotic resistance genes acquired?

Answer 16

Transduction
Transformation
Conjunction

Question 17

Why are Carbapenem-resistant bacteria a public health concern?

Answer 17

Carbapenem-resistant bacteria are resistant to carbapenem antibiotics, which are considered the last line of defense to treat multidrug-resistant bacterial infections

Question 18

What can be done to prevent antibiotic resistance?

Answer 18

• Stop inappropriate use of antibiotics in humans, animals and plants
• Control the release of antibiotics into the environment
• Invest in the identification and development of new antibiotics and antibiotic alternatives