Gram Negative Bacteria

Question 1

Does salmonella ferment lactose?

Answer 1

NO

Question 2

What type of organisms is pseudomonas?

Answer 2

Strict aerobic bacilli water and soil organisms

Contaminates medical equipment

Hospital acquired cause of sepsis: pneumonia, UTI Respiratory infection in cystic fibrosis

Question 3

What causes tuberculosis?

Answer 3

Mycobacterium tuberculosis

Question 4

What is the test for syphilis?

Answer 4

Serology, nucleic amplification tests

Question 5

What type of organism is E.Coli?

Answer 5

Coliform - large gram negative aerobic bacilli

Question 6

What are the strains of chlamydia that cause respiratory infection?

Answer 6

Chlamydophila pneumoniae

Chlamydophila psittaci - contact with birds

Question 7

Name a microaerophilic spiral bacilli

Answer 7

Helicobacter pylori - natural habitat is human stomach - damages mucosa and causes ulcers

Question 8

What causes leprosy?

Answer 8

Mycobacterium leprae

Question 9

What is the ZN stain used for?

Answer 9

Mycobacterium species

Question 10

What family do Coliforms belong in?

Answer 10

Enterobacteriaceae Inhabitants of the gut

Question 11

What strain of chlamydia is responsible for the Ophthalmic and genital tract infection?

Answer 11

Chlamydia trachomatis - trachoma (tropical eye infections) Can lead to pelvic inflammatory disease and infertility

Question 12

What does salmonella cause?

Answer 12

Enterocollitis, with or without bloody diarrhoea

Question 13

What does typhoid cause?

Answer 13

Fever and constipation

Question 14

What are the sub divisions of gram negative aerobic bacilli?

Answer 14

Large (coliforms)

Small

Question 15

What type of organism is salmonella?

Answer 15

Gut pathogen Coliform

Question 16

What type of bacteria is chlamydia?

Answer 16

Obligate intracellular bacteria

Question 17

Give an example of a spirochaetes

Answer 17

Treponem pallidum - syphilis

Borrelia burgdorferi - lymes disease

Question 18

What does Moraxella Catarrhalis cause?

Answer 18

Respiratory tract infections

Question 19

What are the virulence mechanisms of Escherichia coli?

Answer 19

pili, capsule, endotoxin and exotoxins produced

Question 20

What does microaerophilic mean?

Answer 20

Requires little free oxygen

Question 21

What are the important anaerobes? (BACILLI)

Answer 21

Bacteriodes Fragilis - normal colonic flora

Causes intra-abdominal abscess

Question 22

Define congenital

Answer 22

Present from birth

Question 23

What are the gram negative bacilli other than coliforms?

Answer 23

Bordetella pertusis - whooping cough

Haemophilus infuenzae - cocco bacilli (mixed appearance) respiratory tract infection - capsulate form formerly an important cause of meningitis

Question 24

What is meant by miscellaneous bacteria

Answer 24

Can’t be stained with gram stains

Can’t be cultured under standard methods Mycobacterium Spirochaetes Chlamydia

Question 25

What is the test for gram negative bacilli?

Answer 25

Lactose fermentation

Question 26

Name a curved microaerophilic gram negative bacilli

Answer 26

Campylobacter - commonest cause of bacterial diarrhoea in the UK

Question 27

How is diagnosis of chlamydia achieved?

Answer 27

Nucleic acids amplification tests

Question 28

What are the stages of lymes disease?

Answer 28

1. Skin rash 2. Systemic illness - cardiac or neurological and musculoskeletal symptoms 3. Chronic disease - skin, nervous system or joint abnormalities

Question 29

What are the forms of Neisseria spp that are of clinical significance?

Answer 29

Neisseria Meningitidis - meningitis and septicaemia Neisseria ghonorrhoeae - urethritis in men - pelvic inflammatory disease

Question 30

What are the stages of syphilis?

Answer 30

Primary - Non-painful skin legions Secondary - Systemic illness and rash Latent - symptomatic episodes may occur Tertiary - central nervous system Congenital - stillbirth, neonatal death or disease

Question 31

What type of bacteria are Neisseria spp and Moraxella catarrhalis?

Answer 31

Aerobic gram negative cocci

Question 32

Does E Coli ferment lactose?

Answer 32

Yes

Question 33

What is used to detect spirochaetes?

Answer 33

Dark ground microscopy or immunofluorescence - Often diagnosed by serology

Question 34

What is the cause of typhoid fever?

Answer 34

Salmonella typhi

Question 35

What other commensals of the gut exist? (apart from E.Coli)

Answer 35

Klebsiella - UTI and pneumonia Proteus spp - UTI

Question 36

Name an oral anaerobe

Answer 36

Prevotella - cause of dental abscess (pus that forms in the teeth and gums), aspiration pneumonia, human and animal bite infections.

Question 37

Name another gut pathogen that isn't salmonella or E.Coli

Answer 37

Shigella - diarrhoea, dysentery

Question 38

What is the infection usually associated with Ecoli?

Answer 38

Urinary tract infection Enterotoxogenic E.Coli - commonest cause of travellers diarrhoea Enterohaemorrhagic E.coli - Bloody diarrhoea Haemolytic uraemic syndrome