Effect of Aluminium Magnesium Silicate on Avian Influenza Virus sub Type H5n1
ABSTRACT
Effect of Aluminium – Magnesium Silicate (AMS) on Avian Influenza Virus was tested in vitro by incubating an isolate of a highly pathogenic Avian Influenza Virus (AIV) involved in an outbreak of the disease in Nigeria, with a synthetic AMS.
The isolate was a confirmed Influenza virus type A, subtype H5N1. An equal amount of the Virus sample and of the AMS, on a volume to weight (v/w) basis, were incubated at room temperature for one hour and then centrifuged at 3000 revolutions per minute.
The supernatant was tested for viral haemagglutination (HA) titre and for Mean Death Time (MDT) and Embryo Mortality rate (EMR) in embryonated chicken eggs.
Incubating samples of the AIV isolates with the synthetic AMS, reduced volumes of the samples at a mean rate of 24.3%.
It also reduced the viral (HA) titre from a mean of 73±32.72 to 1.4 ±0.43 (P<0.05) and EMR from 100% to 65%. MDT of chicken embryos inoculated with the AIV increased from 76 ±4.38 hours to 130 ±17.27 hours (P< 0.05).
When three portions of a sample of the AIV were incubated with the AMS once, twice and thrice respectively, MDT of chick embryos inoculated with the isolate increased from 64 hours to 104 hours in the portion incubated once.
In the two portions where the incubation was repeated EMR was reduced from 100% to zero.
TABLE OF CONTENTS
Title page – – – – – – – – — i
Dedication – – – – – – – – — ii
Certification – – – – – – – – – iii
Acknowledgment – – – – – – – — iv
Abstract – – – – – – – – — v
Table of contents – – – – – – – – – – vi
Chapter One : Introduction – – – – – 1
2.0 Chapter Two: Literature review – – – – – 4
2.1 Viruses – – – – – – – – – 4
2.1.1.Classes of viruses – – – – – – – 5
2.1.2 Orthomyxoviridae – – – – – – – 7
2.1.3 Avian Influenza viruses – – – – – – 7
2.1.4 Avian Influenza – – – – – – – 8
2.1.4.1 History – – – – – – – – 8
2.1 4.2 Aetiology – – – – – – – – 8
2.1.4.3 Natural hosts of Avian Influenza viruse – – – – 10
2.1.4 .4 Transmission of Avian InfluenzaVirustobirds – – – 11
2.1.4.5 Spread of Avian Influenza Viruse – – – – – 13
2.1.4.6 Epizootiology of Avian Influenza Virus in poultry – – – 13
2,1.4.7 Pathogenesis of the HPAI Viruses in poultry – – – 15
2.1.4.8 Clinical signs and Lesions of Avian Influenza disease in birds – 17
2.1.4.9 Economic consequences of Avian Influenza – – — 19
2.1.4.10. Pandemic potential of present outbreaks of Avian Influenza — 19
2.1.4.11 .Confirmation of Diagnosis of Avian Influenza – – – 21
2.1.4.12 Control measures for Avian Influenza – – – – 21
2.2. Aluminium – Magnesium Silicate – – – – – 23
2.2.1.Synthesis of Aluminium – Magnesium Silicate – – – 24
2.2.2. Aluminium–Magnesium Silicate as a stabilizing agent for other drugs – 24
2.2.3. Antiviral effects of Aluminium – Magnesium Silicate – – 26
Chapter Three: Materials and methods – – – – 27
3.1 Materials – – – – – – – 27
3.2 Methods – – – – – – – — – 28
Chapter Four: Results – – – – – — – 30
Chapter Five : Discussion – – – – — – 34
References – – – – – – – — – 38
List of abreviations – – – – – – — – 50
Appendices – – – – – – – — – 52
INTRODUCTION
1.1 Avian influenza
Viruses forming the Orthomyxoviridae have enveloped RNA viruses with single-stranded genome of negative sense (i.e. the virus RNA is complementary to the messenger RNA) which are divided into eight segments.
Proteins are associated with the RNA genome to form the nucleoprotein-RNA-polymerase complex (Jordan, 1999).
The matrix protein surrounding the genome complex is enveloped in a lipid membrane which is covered by two different surface projection proteins with which haemagglutinin and neuraminidase activities are associated, separately.
The gene for each of the structural proteins, or its precursor protein, is located on a separate genome segment.
This segmentation is an important property of the influenza viruses because, it allows reassortment to occur if two of the viruses infect and replicate in the same cell at the same time (Jordan, 1999).
By negative contrast electron microscopy, Orthomyxoviruses appear as roughly spherical or filamentous particles, 80 – 120nm in diameter on cross-section (Jordan, 1999). At present, the Orthomyxoviridae family consists of one genus, formed from influenza type A and influenza type B viruses.
Influenza type C viruses represent probable, a second genus. To date, only influenza A viruses have been isolated from birds. The Viruses are typed into A, B or C on the basis of the nucleocapsid or matrix antigen which they process (Jordan,1999).
REFERENCES
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Capau,I and Mutinelli,F. (2001). Low pathogenic(LPAI) and highly pathogenic(HPAI) avian influenza in turkey and chicken. In:Capua,I., Mutinelli,F.(eds),A colour atlas and text on avian influenza, Papi Editore, Bologna
