Lecture 6 - Anti Infectives

Question 1

What is an antibiotic?

Answer 1

A chemical substance produced by various species of microorganisms (bacteria, fungus, actinomyces) that suppresses growth or destroys other microorganisms

Question 2

What is the safest drug used in Medicine?

Answer 2

Antibiotic

Question 3

What is a Gram - bacteria consist of?

Answer 3

thin peptidoglycan layer with lipoprotein and lipopolysaccharide (endotoxin)

Question 4

What is a Gram + bacteria consist of?

Answer 4

Gm + bacteria: thick peptidoglycan layer

Question 5

Why is resident flora important?

Answer 5

Vitamin B, Vitamin K and Digestive system is required for this system to function

Question 6

What is the resident flora of the eye?

Answer 6

Conjunctiva

Question 7

What are the 2 most popular ocular bacteria ?

Answer 7

Staphlococcus and Streptococcus

Question 8

A pt. comes in and you notice they have pneumoniae and the pt has come in with bad vision, what could be a possible outcome for the vision issue?

Answer 8

Potentially corneal ulcer and in children it causes conjunctivitis

Question 9

What are the 2 most common Staphlococcus?

Answer 9

Aureus - More virulent (MRSA)

Epidermidis - More abundant (MRSE)

Note: We are all carriers of this virulent but if resistance occurs, the entire population will in trouble.

Question 10

What type of a drug do you not use for Nosocomial infections (Gm+)?

Answer 10

Flurorquinilones

Question 11

What type of drug do you use for Gm-?

Answer 11

Fluroquinilones

Question 12

What are the 3 most commone Gm-?

Answer 12

Cocci - Neisseria gonorrhea

Rods - Haemophilus influenzae

Enterics - Psudomonas and Serratia

Question 13

What are the most common water borne bacteria?

Answer 13

Serratia Macescens and Pseudomonas (Enterics)

Question 14

What are two common “host-dependent ocular bacteria”?

Answer 14

Chalmydia - C. trachomatis (gm -)
Finger/fomite (an area that can harbour bacteria) - to eye infection => trachoma
Genitals – to eye infection => inclusion conjunctivitis

Spirochetes
Treponema pallidum (gm -)
STD or mother-to-child => syphilis

Question 15

What 2 bacteria cidal drugs are concentration dependent?

Answer 15

Aminoglycosides and Fluroquinolones

Question 16

What are 3 pearls when you you want to treat

Answer 16

1) Mucopurulent discharge
No discharge = No infection (Mucous discharge is different, which is usually a VIRAL infection, creamy and has color usually)

2) +/- Diffuse conjunctival injection
Sectoral injection = No infection

3) Potential corneal compromise (If bacteria an penetrate the cornea, you are trying to prevent an bacterial infection)

Question 17

What are the 4 cell wall inhibitors?

Answer 17

Penicillin
Cephalosporins
Bacitracin
Vancomycin - IV given and the best Antibiotic to treat MRSA and MRSE

Question 18

What is the main function of Penicillin?

Answer 18

Inhibit transpeptidases (penicillin binding proteins) which create peptide X-links between polysaccaride chains that form peptidoglycan

Question 19

What are the 2 types of PCN, that are PCNase Sensitive?

Answer 19

Pen G and Pen V

Question 20

What are the 3 types of PCN’s that are PCNase resistant?

Answer 20

Semi synthetic Methicillin, Flucloxacillin and Dicloxacillin

Question 21

What are the two types of Aminopenicillins?

Answer 21

Ampicillin +/- sulbactam and

Amoxicillin +/- clavulanate