Gram negative bacteria

Question 1

What are the 4 main groups gram negative bacteria are split into?

Answer 1

1. Bacilli
2. Cocco-bacilli
3. Curved bacilli
4. Cocci

Question 2

What are aerobic bacilli grown on?

Answer 2

Grow on MacConkeys

Question 3

What 2 categories are aerobic bacteria split into?

Answer 3

1. lactose fermenter

2. non-lactose fermenter

Question 4

What are the 2 lactose fermenter bacilli?

Answer 4

1. enterohaemorrhagic e.coli (coliform)

2. Campylobacter species

Question 5

What does enterohaemorrhagic e.coli cause?

Answer 5

-E.Coli 0157 best known as a cause to bloody diarrhoea and haemolytic-uraemic syndrome.

Question 6

What does campylobacter species cause?

Answer 6

Most common cause of ‘travellers’ diarrhoea

Question 7

What are the 5 lactose non- fermenter bacilli? (SSSPP)

Answer 7

1. salmonella enterica (coliform)
2. salmonella typhi (coliform)
3. Shigella species (coliform)
4. Proteus species (coliform)
5. Pseudomonas species (not coliform)

Question 8

What does salmonella enterica cause?

Answer 8

Food poisoning, vomiting, diarrhoea

Question 9

What does salmonella typhi cause?

Answer 9

causes enteric fever (typhoid)

Question 10

What does shigella species cause?

Answer 10

4 species, only 1 endemic in UK (Shigella sonnei). Causes dysentery (blood and pus in stools). Low infective dose.

Question 11

What does proteus species cause?

Answer 11

UTIs

Question 12

What does pseudomonas species cause?

Answer 12

Found on skin flora, cause inflammation and sepsis

Question 13

What are the 3 anaerobic bacilli?

Answer 13

1. Bacteroides fragilis
2. prevotella (oral anaerobe)
3. Porphyromonas (oral anaerobe)

Question 14

What does bacteroides fragilis cause?

Answer 14

-most prominent in normal large bowel flora and faeces. —often present in intra-abdominal infections. Resistant to penicillan but sensitive to metrondiazole.

Question 15

what does prevotella (oral anaerobe) cause?

Answer 15

Involved in dental infections and aspiration pneumonia. Usually both penicillin and metrondiazole sensitive.

Question 16

what does porphyromonas? (oral anaerobe)

Answer 16

Miscellaneous anaerobes foind in mouth and elsewhere

Question 17

What is the main cocco-bacilli?

Answer 17

Haemophilus Influenzae

Question 18

What does Haemophilus Influenzae cause?

Answer 18

Capsulated strain type b (Hib) cause childhood meningitis and epiglottitis, but all children are now offered immunisation. Non-capulate strains cause exacerbations of COAD, sinusitis and otitis media.

Question 19

What are the 3 curved bacilli?

Answer 19

1. helicobacter pylori
2. campylobacter species
3. vibrio cholerae

Question 20

What does helicobacter pylori cause?

Answer 20

Strongly urease positive. Causes gastritis and peptic ulceration.

Question 21

What does campylobacter species cause?

Answer 21

diarrhoea with blood

Question 22

What does vibrio cholerae cause?

Answer 22

Causes severe diarrhoea in the form of Cholera. Ingested in water contaminated by human faeces.

Question 23

What are the 3 cocci bacteria?

Answer 23

1. Maraxella catarrhalis
2. Neisseria gonorrhoeae
3. Neisseria meningitidis (meningococci)

Question 24

What does maraxella catarrhalis cause?

Answer 24

Respiratory pathogen causing exacerbations of chronic bronchitis. Also causes otitis media in children.

Question 25

What does neisseria gonorrhoeae cause?

Answer 25

Cause of gonorrhoea. Must be cultured quickly or it dies.

Question 26

What does neisseria meningitidis?

Answer 26

Cause of meningococcal septicaemia and meningococcus meningitis. Meningococcus meningitis has high mortality and both should be treated with IV penicillan. Groups A,B and C; vaccine available for A and C only