8. infections caused by fungi

Question 1

chalk brood pathogen

Answer 1

ascosphaerosis larvarum - ascosphaea apis

Question 2

when was chalk brood discovered

Answer 2

1911 - present in worldwide colonies

Question 3

pathogenesis of mature ascoma - chalk brood

Answer 3

• Dark brown
• transparent ascoma walls
• small spherical shaped asci
• when ascoma’s rupture spores released

Question 4

predisposing factors of chalk brood

Answer 4

• high humidity
• decreased temp
• early summer
• small colonies more impacted

Question 5

how long are chalk brood spores infective for

Answer 5

spores infective for 10-15 years

Question 6

what bees suffer from chalk brood

Answer 6

drone larvae

Question 7

how are spores of chalk brood spread

Answer 7

beekeeper activity

Question 8

age of larvae affected by chalk brood

Answer 8

only 3-4 day old larvae affected

Question 9

how can a bee get infected per os

Answer 9

through host gut lining
hyphae penetrate gut wall
mycelium break out
larvae die

Question 10

symptoms of chalk brood

Answer 10

• head of larvae will be unaffected
• no smell of dead larvae
• young larvae show no signs

Question 11

colour of dead larvae infected with chalk brood

Answer 11

• mummified
• chalky white
• dark blue grey/black

Question 12

mummies of chalk brood

Answer 12

if mummies are still contained in capped cells, shake comb = mummies will be heard rattling in the cells

Question 13

visual detection of chalk brood

Answer 13

beekeeper can diagnose based on hard shrunken chalk like mummies

Question 14

cultivation of chalk brood

Answer 14

with potato dextrose and yeast extract 30 degrees

Question 15

chemical treatment of chalk brood

Answer 15

little effect - spores destroyed with ethylene oxide

Question 16

Control of chalk brood:

Answer 16

• Re-queening: from chalk brood-free colony recommended

Question 17

zoonotic fungus remember zoontoic

Answer 17

stone brood

Question 18

what broods does stone brood affect:

Answer 18

• uncapped and capped broods
• larvae and adult bees
• • affect the head of the larve*

Question 19

predisposition to stone brook:

Answer 19

chilly and wet climate

Question 20

most common fungus of stone brood

Answer 20

• aspergillus flavus
• A fumigatus which is less common

Question 21

colour of stone brood

Answer 21

yellow/ grey green

Question 22

where is stone brood found

Answer 22

in soil and cereal products - may cause resp diseases in other animals

Question 23

pathogenesis of stone brood

Answer 23

per os by feeding

Question 24

what form on the surface of larvae in stone brood

Answer 24

• conidiophores
• containing spores
• false skin forms within 2-3 days

Question 25

symptoms of larvae infected with chalk brood

Answer 25

- white and fluffy then turn brownish green yellow and STONE HARD - No smell of dead larva

Question 26

*colour of A.flavus stone brood*

Answer 26

yellow green

Question 27

*colour of A. fumigatus stone brood*

Answer 27

gray green

Question 28

*colour of A.niger stone brood*

Answer 28

black

Question 29

*treatment of stone brood*

Answer 29

- no effective method - kill infected colonies and moult wax - 30 mins at 60 degrees

Question 30

biohazard risks of stone brood

Answer 30

aflatoxins are carcinogenic if inhaled or ingested

Question 31

*is stone brood notifiable*

Answer 31

only in several countries

Question 32

*Nosemosis affect ?*

Answer 32

- adult bees (worker, queens and drones)

Question 33

When can Nosemosis be infected?

Answer 33

after emerging

Question 34

*Pathogens of Nosemosis:*

Answer 34

- Nosema ceranae - Nosema apis

Question 35

*Infective stage of Nosemosis ?*

Answer 35

- Spore

Question 36

*what are spores in Nosemosis resistant to ?*

Answer 36

- environmental degradation - retain their viability for > 1 year

Question 37

*Pathogenesis of Nosemosis:*

Answer 37

- spores after 5 days at 30degree, voided in the excreta of the bee

Question 38

*wich time of the year do you see symptoms of Nosemosis:*

Answer 38

- autumn - winter - sometimes early spring

Question 39

*Symptoms fo Nosemosis:*

Answer 39

- *dysentry* - unable to fly and may crawl about the hive entrance or stand trembling on top of the frames - signs of faeces on combs during winter with may be dark and scaly in cells

Question 40

What happens with infected queens and workers in Nosemosis:

Answer 40

- queens: egg laying and die within 1-2 weeks - workers: start to forage earlier

Question 41

What is the most globally prevalent honeybee:

Answer 41

Nosema Ceranae

Question 42

Diagnosis of Nosemosis:

Answer 42

- microscopic examination of digestive tract of dead adults - PCR - detection of spores

Question 43

*Which staining do we use in diagnose of Nosemosis?*

Answer 43

methyl blue staining

Question 44

*Treatatment of Nosemosis:*

Answer 44

- Fumagillin (25 mg active per litre of sugar syrup) antibiotic preferably at time when colony likely to encounter stress condition, such as during long winter / rainy season - should disinfect heavily infected colonies