Evaluation of the efficacy of two different tulathromycin treatments in weaned piglets infected intratracheally with Haemophilus parasuis serovar 5 [Elektronische Ressource] / Rose-Leah Kavita Austin-Busse

Austin-Busse, Rose-Leáh

Informations

• Publié par: ludwig-maximilians-universitat_munchen
• Publié le: 01 janvier 2010
• Nombre de lectures: 8
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

From the Clinic for Swine
(Head: Prof. Dr. Dr. habil. Karl Heinritzi)
of the Veterinary Faculty
of the Ludwig-Maximilians-University Munich
and the
Clinic for Swine
(Head: Prof. Dr. Mathias Ritzmann)
of the Veterinary University Vienna






Evaluation of the efficacy of two different tulathromycin
treatments in weaned piglets infected intratracheally with
Haemophilus parasuis serovar 5




Inaugural-Dissertation
for the veterinary doctorate
of the Veterinary Faculty
of the Ludwig-Maximilians-University Munich

Rose-Leah Kavita Austin-Busse
Georgetown, Guyana


Munich 2010
Printed with permission from the Veterinary Faculty
of the Ludwig-Maximilians-University Munich











Dean: Univ.-Prof. Dr. Joachim Braun
Referent: Univ.-Prof. Dr. Dr. habil. Karl Heinritzi
Korreferent:















Day of Promotion:
th24 July 2010















EmmanuelContents I
Contents
Contents..................................................................................................................... I
Abbreviations............................................................................................................ V
1 Introduction ........................................................................................................ 1
2 Literature review ................................................................................................ 3
2.1 Haemophilus parasuis ................................................................................ 3
2.1.1 Etiology ................................................................................................... 3
2.1.2 Epidemiology........................................................................................... 5
2.1.3 Experimental infection............................................................................. 9
2.1.4 Pathogenesis and virulence .................................................................. 12
2.1.5 Clinical signs ......................................................................................... 15
2.1.6 Gross and microscopic lesions.............................................................. 17
2.1.7 Differential diagnosis............................................................................. 18
2.2 Diagnosis ................................................................................................... 19
2.2.1 Selection of animals and sampling sites................................................ 19
2.2.2 Sampling procedures ............................................................................ 20
2.2.3 Bacterial isolation .................................................................................. 20
2.2.4 Molecular biological methods ................................................................ 21
2.2.5 Further diagnostic methods................................................................... 23
2.3 Therapy ...................................................................................................... 25
2.3.1 Antimicrobial use in food animal production .......................................... 25
2.3.2 Antimicrobial treatment for HPS ............................................................ 25
2.3.3 Antimicrobial susceptibility patterns for HPS ......................................... 26
2.3.4 Tulathromycin........................................................................................ 27
2.3.5 Prophylaxis and immunity ..................................................................... 29
3 Material and Methods ...................................................................................... 32
3.1 Study aim ................................................................................................... 32
3.2 Study animals ............................................................................................ 32
3.3 Study design.............................................................................................. 33
3.3.1 Housing ................................................................................................. 34
3.3.2 Biosecurity............................................................................................. 36 Contents II
3.3.3 Administration of tulathromycin ............................................................. 36
3.3.4 Preparation of challenge inoculum ........................................................ 36
3.3.5 Administration of inoculum .................................................................... 37
3.3.6 Euthansia .............................................................................................. 38
3.4 Clinical examinations................................................................................ 38
3.5 Necropsy.................................................................................................... 40
3.6 Sample collection and Diagnostic ........................................................... 42
3.6.1 Blood sampling...................................................................................... 42
3.6.2 Synovial and cerebrospinal fluid collection............................................ 43
3.6.3 Collection and processing of serosal swabs.......................................... 43
3.6.4 Bacteriological culture ........................................................................... 44
3.6.5 Histopathological examination............................................................... 44
3.6.6 Polymerase chain reaction (PCR) analysis for HPS.............................. 45
3.7 Statistics .................................................................................................... 45
4 Results.............................................................................................................. 47
4.1 Screening, animal numbers and data collection .................................... 47
4.2 Clinical results........................................................................................... 48
4.2.1 Mortalities.............................................................................................. 48
4.2.2 Clinical examinations............................................................................. 49
4.2.3 Average daily gain (ADG)...................................................................... 51
4.2.4 Rectal temperatures.............................................................................. 52
4.2.5 Blood examination (Leukocyte population)............................................ 53
4.3 Gross lesions............................................................................................. 55
4.3.1 Lung assessment .................................................................................. 55
4.3.2 Synovial fluid assessment ..................................................................... 56
4.3.3 Cerebrospinal fluid assessment ............................................................ 57
4.3.4 Brain assessment.................................................................................. 58
4.3.5 Assessment of the serosal membranes and cavities............................. 60
4.4 Histopathological lesions ......................................................................... 64
4.5 PCR detection of HPS genome................................................................. 65
4.6 Bacterial isolation of HPS......................................................................... 66
4.7 Association between HPS detection in collective serosal swabs by PCR
and bacterial culture ................................................................................. 67 Contents III
4.8 Associations between HPS detection in samples from challenged pigs
and clinical results.................................................................................... 67
4.8.1 Association between HPS detection by PCR and bacterial culture and
the median total daily clinical score....................................................... 67
4.8.2 Association between HPS detection by PCR and bacterial culture and
time of death.......................................................................................... 68
4.9 Association between HPS detection in samples from challenged pigs
and gross lesions...................................................................................... 70
4.9.1 Association between HPS detection in collective serosal swabs and the
total inflammation score ........................................................................ 70
4.9.2 Association between HPS detection in collective serosal swabs and
pleuritis, pericarditis, and peritonitis ...................................................... 71
4.9.3 Association between HPS genome detection in cerebrospinal fluids,
brain swabs and the assessment of the brains and cerebrospinal fluids73
4.9.4 Association between HPS genome detection in synovial fluids, joint
capsules and the synovial fluid assessment......................................