Inhoudsopgave
Transkingdom interactions and their impact on arbovirus pathogenesis ............................................. 2
1. Arbovirus ............................................................................................................................. 2
1.1 Arbovirus transmission ........................................................................................................ 2
1.2 High disease burden by vector-borne disease ....................................................................... 3
2. Dengue virus ........................................................................................................................ 3
2.1 Antibody-dependent enhancement...................................................................................... 3
2.2 DENV cases on the rise in France ......................................................................................... 4
3. Zika virus.............................................................................................................................. 4
4. Chikungunya fever ................................................................................................................ 4
4.1 Chikungunya virus on the rise in 2015 ................................................................................... 5
5. Transkingdom interactions .................................................................................................... 5
5.1 Transkingdom interactions affect virus infections ................................................................. 5
5.2 Effect of bacteria on arbovirus disease? ............................................................................... 5
5.3 Effect of gut bacteria on flaviviral disease ............................................................................. 6
5.4 Effect of gut bacteria on CHIKV infection .............................................................................. 6
5.5 What about the skin microbiome? ........................................................................................ 6
6. The life cyclus of a mosquito ................................................................................................. 8
6.1 How do mosquitoes find us? ................................................................................................ 8
6.2 Insecticide resistance ......................................................................................................... 9
6.3 Mosquito microbiome ......................................................................................................... 9
Synopsis: Flow cytometry applied to microorganisms ..................................................................... 12
1. Flow cytometer (FC) principles............................................................................................ 12
2. FACS (Fluoresence-activated cell sorting) ........................................................................... 12
3. Flow cytometry (FC) Data processing .................................................................................. 13
4. Flow cytometry (FC) Data analysis ...................................................................................... 13
5. Flow cytometry (FC) challenges .......................................................................................... 13
6. Flow cytometry (FC) applications ........................................................................................ 14
7. Notes ................................................................................................................................. 14
1
, Transkingdom interactions and their impact on arbovirus pathogenesis
1. Arbovirus
Arbovirus = arthropod-borne virus
• Arthropoda
- Largest phylum in the animal kingdom
- Cold-blooded
- External skeleton of chitin
- Segmented body
>130 arboviruses causing human diseases → also a problem for animals and plants
Most arboviruses of public health importance belong to one of three virus genera:
• Flavivirus
• Alphavirus
• Bunyavirus
Replicate both in vertebrates and arthropods
Transmission when arthropod takes blood meal
Viremia needs to be high enough to sustain the transmission cycle → there must be enough virus present in the
blood in the vertebrate → otherwise, the mosquito or tick cannot become infected.
• We can become ill, but if there is too little virus present, we will not be able to infect a new mosquito.
1.1 Arbovirus transmission
→ Mosquitoes are less active in the winter → less transmission during the winter
months.
Enzootic cycle: this is the natural cycle of transmission between arthropods and wild
animal hosts.
• Humans are not normally involved in this cycle.
- People in the rainforest can become directly infected.
• The virus persists in nature this way, even when there are no human
cases.
Epizootic cycle: sometimes, the virus can spread from the enzootic cycle into
domestic or peridomestic animals (e.g. horses, pigs)
• This can cause outbreaks among animals.
• During such outbreaks, there is an increased risk that humans may also
be infected especially if they live near the affected animals or vectors.
- When you work on a farm or go to a farm
Urban epidemic cycle: in this cycle, humans become the main amplifying hosts.
• The virus is transmitted human → mosquito → human, without needing animals.
Arboviruses are a worldwide problem: vector-borne diseases >17% of al infectious diseases → not only in the
tropics, but all over the world!
• Growing number of arbovirus outbreaks
- Climate change
- International travel
- Urbanization → people live closer to wooded areas → then you can get spill-over
2
Transkingdom interactions and their impact on arbovirus pathogenesis ............................................. 2
1. Arbovirus ............................................................................................................................. 2
1.1 Arbovirus transmission ........................................................................................................ 2
1.2 High disease burden by vector-borne disease ....................................................................... 3
2. Dengue virus ........................................................................................................................ 3
2.1 Antibody-dependent enhancement...................................................................................... 3
2.2 DENV cases on the rise in France ......................................................................................... 4
3. Zika virus.............................................................................................................................. 4
4. Chikungunya fever ................................................................................................................ 4
4.1 Chikungunya virus on the rise in 2015 ................................................................................... 5
5. Transkingdom interactions .................................................................................................... 5
5.1 Transkingdom interactions affect virus infections ................................................................. 5
5.2 Effect of bacteria on arbovirus disease? ............................................................................... 5
5.3 Effect of gut bacteria on flaviviral disease ............................................................................. 6
5.4 Effect of gut bacteria on CHIKV infection .............................................................................. 6
5.5 What about the skin microbiome? ........................................................................................ 6
6. The life cyclus of a mosquito ................................................................................................. 8
6.1 How do mosquitoes find us? ................................................................................................ 8
6.2 Insecticide resistance ......................................................................................................... 9
6.3 Mosquito microbiome ......................................................................................................... 9
Synopsis: Flow cytometry applied to microorganisms ..................................................................... 12
1. Flow cytometer (FC) principles............................................................................................ 12
2. FACS (Fluoresence-activated cell sorting) ........................................................................... 12
3. Flow cytometry (FC) Data processing .................................................................................. 13
4. Flow cytometry (FC) Data analysis ...................................................................................... 13
5. Flow cytometry (FC) challenges .......................................................................................... 13
6. Flow cytometry (FC) applications ........................................................................................ 14
7. Notes ................................................................................................................................. 14
1
, Transkingdom interactions and their impact on arbovirus pathogenesis
1. Arbovirus
Arbovirus = arthropod-borne virus
• Arthropoda
- Largest phylum in the animal kingdom
- Cold-blooded
- External skeleton of chitin
- Segmented body
>130 arboviruses causing human diseases → also a problem for animals and plants
Most arboviruses of public health importance belong to one of three virus genera:
• Flavivirus
• Alphavirus
• Bunyavirus
Replicate both in vertebrates and arthropods
Transmission when arthropod takes blood meal
Viremia needs to be high enough to sustain the transmission cycle → there must be enough virus present in the
blood in the vertebrate → otherwise, the mosquito or tick cannot become infected.
• We can become ill, but if there is too little virus present, we will not be able to infect a new mosquito.
1.1 Arbovirus transmission
→ Mosquitoes are less active in the winter → less transmission during the winter
months.
Enzootic cycle: this is the natural cycle of transmission between arthropods and wild
animal hosts.
• Humans are not normally involved in this cycle.
- People in the rainforest can become directly infected.
• The virus persists in nature this way, even when there are no human
cases.
Epizootic cycle: sometimes, the virus can spread from the enzootic cycle into
domestic or peridomestic animals (e.g. horses, pigs)
• This can cause outbreaks among animals.
• During such outbreaks, there is an increased risk that humans may also
be infected especially if they live near the affected animals or vectors.
- When you work on a farm or go to a farm
Urban epidemic cycle: in this cycle, humans become the main amplifying hosts.
• The virus is transmitted human → mosquito → human, without needing animals.
Arboviruses are a worldwide problem: vector-borne diseases >17% of al infectious diseases → not only in the
tropics, but all over the world!
• Growing number of arbovirus outbreaks
- Climate change
- International travel
- Urbanization → people live closer to wooded areas → then you can get spill-over
2
