independent assignment

Question 1

what is the name of your microbe

Answer 1

mycobacterium ulcerans

Question 2

why is this microbe worth studying

Answer 2

• it causes a skin disease known as Buruli Ulcer disease which affects humans
• Buruli is the third most common mycobacterial infection

Question 3

what is unique about your microbe

Answer 3

• it has the ability to produce a potent toxin called mycolacetone
• has a small infectious dose

Question 4

has your microbe been in the popular media/news and if so why is it news worthy?

Answer 4

• Buruli ulcer is a “neglected” tropical disease, but the media has focused on its contributions to long term disabilities and large painless ulcers on the skin

Question 5

Habitat - where is the organism found or where is it likely to be isolated

Answer 5

• 33 countries with tropical and subtropical regions
• West Africa and Australia mainly, but also seen in South America and western pacific regions
• most likely to be found in aquatic ecosystems, tropical rainforests and wetlands near stagnent, slowmoving waters

Question 6

what can you deduce about it’s preferred environmental conditions (pH, temperature, etc.)

Answer 6

• temperature = 29-33 degrees celcius
• oxygen concentration = low (~2.5%) - obligate aerobic respiration
• pH = moderately acidic (pH 5.4-7.4)
• forms biofilms on aquatic organisms

Question 7

does this organism have any unusual metabolic features? describe them and the properties that allow of this unusual tolerance process

Answer 7

• evolved via lateral gene transfer
• form spores which are resistant to antibiotics
• uses methylmalonyl-CoA pathway for energy production of TCA cycle
• highly clonal

Question 8

to what domain does it belong

Answer 8

domain bacteria

Question 9

what does the organism look like

Answer 9

• rod shaped
• thick and waxy cell wall
• high GC content
• Gram positive
• will stain red in acid fast staining

Question 10

does it posses any special attributes/structures/properties/characteristics

Answer 10

• waxy cell all which in mycolic acid and lipids: males it extremely resistant to environmental factors

Question 11

is it a pathogen? if so what is its host range and mode of transmition

Answer 11

• yes it is a pathogen
• host range is humans and animals (mostly in skin and bone cells)
• aquatic plants to soil are resevoirs of infection
• mode of transmission is unknown but factors include contact with water, soil and the environment

Question 12

what are its virulence factors? does it produce a toxin? what is the effect of the toxin on the host?

Answer 12

toxin = mycolacetone
- it is very potent
- immunosupression by altering cytokine production
- enablesdisease to progress rapidly with no pain or fever
- responsible for skin lesions and tissue necrosis

Question 13

is the infection treatable? are vaccines available?

Answer 13

• can treat with oral antibiotics Rifampicin and clarithromycin
• can sometimes use surgery to promote healing of lesions
• no specific vaccine but vaccine for Bacillus Calmette-Guerin provides limited protection

Question 14

is it a microbe with potential for the use of BIOTECHNOLOGY? and if so how?

Answer 14

• could be used for drug production and genomics
• more studies to predict metabolic pathways from genome sequence data to isolate it in pure cultures from environmental sources

Question 15

What one aspect related to this organism that is subject of current research efforts?

Answer 15

• development of ONE health frameworks: to study transmission between different species
• establishing vector competence: good evidence to show that mosquitos are involved in transmission