Bacteria

Question 1

7 Classifications of Bacteria

Answer 1

Aerobic
Anaerobic

Gram positive
Gram negative

Atypical bacteria

• bacilli -> rod shaped
• cocci -> circular

Question 2

Aerobic vs anaerobic bacteria

Answer 2

aerobic require oxygen whereas anaerobic bacteria do not

Question 3

Gram +ve/-ve bacteria differences

Answer 3

Gram +ve have thick peptidoglycan cell wall
– stains crystal violet with gram stain

Gram -ve bacteria don’t have this peptidoglycan cell wall

• • Dont stain crystal violet with gram stain
• • Do stain with other stains

Question 4

Atypical bacteria

Answer 4

Cannot be stained or cultured in the normal way

Question 5

Bacterial folic acid

Answer 5

Essential for synthesis and regulation of DNA within the bacteria

Cannot be created or directly imported into the cell - requires chain of intermediaries

PABA absorbed across cell wall and membrane

PABA converted to DHFA which is converted to THFA

THFA then converted to folic acid

Question 6

Gram stain techniqueucan

Answer 6

1) add crystal violet stain
- - binds molecules in thick peptidoglycan cell wall (gram +ve) turning them violet

2) add counterstain such as SAFARIN
- - Which binds to cell membrane in bacteria who dont gave cell wall (gram -ve) turning them red/pink

Question 7

Gram positive cocci:

Answer 7

Staphylococcus

Streptococcus

Enterococcus

Question 8

Gram positive rods:

Answer 8

Corney Mike’s List of Basic Cars (x5)

Corneybacteria
Mycobacteria
Listeria
Bacillus
Nocardia

Question 9

Gram-positive anaerobes

Answer 9

CLAP:

Clostridium
Lactobacillus
Actinomyces
Propionibacterium

Question 10

Gram Negative bacteria (common organisms)

Answer 10

Neisseria meningitidis

Neisseria gonorrhoea

Haemophilus influenza

E. coli

Klebsiella

Pseudomonas aeruginosa

Moraxella catarrhalis

Question 11

Atypical bacteria definition:

Answer 11

The definition of atypical bacteria is that they cannot be cultured in the normal way or detected using a gram stain. Atypical bacteria are most often implicated in pneumonia.

Question 12

Atypical bacteria that cause atypical pneumonia:

Answer 12

MNEMONIC – legions of psittaci MCQs

Legions – Legionella pneumophila

Psittaci – Chlamydia psittaci

M – Mycoplasma pneumoniae

C – Chlamydydophila pneumoniae

Qs – Q fever (coxiella burnetii)

Question 13

Antibiotic treatment options for MRSA

Answer 13

Doxycycline
Clindamycin
Vancomycin
Teicoplanin
Linezolid

Question 14

MRSA definition:

Answer 14

refers to staphylococcus aureus bacteria that have become resistant to beta-lactam antibiotics such as:

• penicillins
• cephalosporins
• carbapenems.

Question 15

MRSA avoidance (screening and eradication)

Answer 15

Can colonise skin and respiratory tract harmlessly

Patients being admitted for surgery or treatment are screened by:

• Nasal swabs
• Groin swabs

If identified eradication takes place which involves:
- Chlorhexidine body wash and antibacterial nasal creams

Question 16

Extended Spectrum Beta Lactamase bacteria (ESBLs) - definition

Answer 16

ESBLs are bacteria that have developed resistance to beta-lactam antibiotics.

They produce beta-lactamase enzymes that destroy the beta-lactam ring on the antibiotic.

They can be resistant to a very broad range of antibiotics.

Question 17

What species do ESBLs tend to be? what do they tend to cause?

Answer 17

e. coli or klebsiella

Typically cause UTI - can cause other infections such as pneumonia

Question 18

What are ESBLs usually sensitive to?

Answer 18

Usually sensitive to carbapenems, such as:

• meropenem
• imipenem