Monitoring of Aspergillus fumigatus development by quantitative PCR and galactomannan enzyme immunoassay from lung tissues of intra -tracheally infected turkeys (Meleagris gallopavo)

Ref ID: 19498

Author:

E Melloul1,6*, T Simon2, N Cordonnier3, R Chermette1, F Botterel4, J Chandenier5,
C Bostvironnois6, J Guillot1, P Arné1

Author address:

1ENVA, ANSES, UPEC, UMR Bipar, Equipe Dynamyc, Maisons-Alfort, France
2ANSES, Epidémiologie, LSA, Maisons-Alfort, France
3ENVA, Anatomie Pathologique, Maisons-Alfort, France
4Faculté de Médecine, ENVA, ANSES, UPEC, UMR Bipar, équipe Dynamyc, Créte

Full conference title:

6th Advances Against Aspergillosis 2014

Abstract:

Purpose:
Aspergillus fumigatus remains a major respiratory pathogen in birds, but diagnosis is still difficult.
In poultry, aspergillosis may induce significant economic losses particularly in turkey production.
The development of experimental models of infection is an essential prerequisite for a better
understanding of the disease pathophysiology through characterization of the early stages of the
fungal development in the air sacs and lungs and evaluation of relevant biological markers.
Methods:
We developed an infection model by intra-tracheal nebulisation of conidia via a stainless steel
gauge atomizer (MicroSprayer® ) in turkeys. We tested different inoculum doses (105, 106, 107, and
108 spores of Aspergillus fumigatus per bird) and assessed the quantity of fungal burden in lungs by
numeration of colony forming units, quantitative PCR and galactomannan enzyme immunoassay
from lung tissues. The histologic examination of lung confirmed the diagnosis of aspergillosis.
Results:
The nebulisation of spores in the trachea of one-week-old turkeys readily induced respiratory
symptoms, typical macroscopic and microscopic lesions and inflammatory responses, whose
intensity increased with the concentration of the inoculum. A significant mortality occurring in the
first 96 hours after inoculation was only observed with the highest inoculum dose. Culture counts,
GM index and qPCR results on one hand and inoculum size on the other hand appeared to be clearly
correlated.
Conclusion:
An intratracheal nebulisation of 108 conidia per bird is necessary to reproduce an acute aspergillosis
in young turkeys. The new model and the markers will be used for the evaluation of the efficacy of
antifungal treatments that could be applied in poultry farms.

Abstract Number: 26

Conference Year: 2014

Link to conference website: http://www.AAA2014.org

New link: NULL

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