Mycoplasma driving you crazy? - sapoultry.co.za · Mycoplasma driving you crazy? MYCOPLASMA...
Transcript of Mycoplasma driving you crazy? - sapoultry.co.za · Mycoplasma driving you crazy? MYCOPLASMA...
Mycoplasma driving you crazy?
MYCOPLASMA REDUCTION
PROGRAMME:
AVENUES FOR FUTURE RESEARCH
Hilda Joubert and Louis Maartens
Fact
Once a bird is infected with Mycoplasma, it is considered chronically infected for life and
subsequent stress may cause disease
Research objectives should focus on
keeping flocks free of infection (difficult)
AND/OR
Reducing the negative economic impact of
mycoplasma on South African poultry
Control strategies for Mycoplasma
infections in commercial poultry include
three general approaches (Kleven, 2008)
Maintaining flocks
free of infection
Biosecurity and effective monitoring
Medication
Useful in preventing clinical signs and
economic losses but cannot be used to
eliminate infection from a flock
Vaccination
Useful long-term solution where
maintaining flocks free of infection is
not feasible, especially on multi-age
commercial egg production sites
Short term objective
Obtain information on the mycoplasma
situation in South Africa
Short term activities
Determine the prevalence and distribution of mycoplasma in the avian breeder flock population in South Africa
A comprehensive coordinated approach to determine prevalence and distribution is needed and should include
• Culture and identification of mycoplasma isolated from
infected flocks
• Confirm identity of mycoplasma with species-
specific mycoplasma polymerase chain reaction
• Determine the prevalence of vertical transmission
• Serological monitoring of unvaccinated flocks
Short term activities
Isolation and characterisation of avian mycoplasmas
or variants involved in field infections
Aligning these mycoplasmas to international
reference strains which will give valuable information
on divergent (new species in same genus that
evolved in parallel) or convergent (new relationships
built on old abilities) evolutionary patterns
Short term activities
Establish if infections with specific variants of
mycoplasma are related to clinical signs or decreased
egg production or downgrading of meat-type birds
Medium term objectives
Establish the efficacy of antibiotics against
Mycoplasma species/variants in South Africa
Susceptibility of mycoplasma, circulating in the field, to
antimicrobials should be determined
Targeted use of a suitable antibiotic for limited periods
assists in overcoming production losses
The following must be considered
• Overuse leads to resistance development which
can result in serious consequences for future
disease control
• Antibiotic residues especially in egg products
• Dose dependent embryo toxicity
Medium term activities
Long term objective
Maintaining flocks free of infection
Long term activities
Will require an integrated approach to the entire
biosystem
• Good biosecurity and decontamination
• Maintaining replacements from mycoplasma-
free sources in a single-age, all-in all-out
management system
• Effective monitoring systems are necessary
aspects of this program
Vaccination may be a suitable long term tool to minimise infection but challenge studies to evaluate long-term efficacy of vaccines used in South Africa is needed
• Vaccination can interfere with surveillance
• Vaccination can be used for control of
mycoplasma where stringent biosecurity measures are not feasible and antibiotic residues in meat or egg products are problematic
Long term activities
To Conclude
It will not be a broad and straight path
We will certainly encounter difficulties
Guidance from experts will be
needed
It will take time
We might have to deviate from set
paths
There will be limitations
Trouble will be found along these
avenues
Involvement from the industry is crucial
It will cost something
The aim is to achieve the goals