Mycoplasma driving you crazy?

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 Medication Biosecurity and effective monitoring 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 speciesspecific 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

Medium term activities 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

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

Long term activities 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

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