Mycoplasmosa control and diagnosis in breeders and broilers

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Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS ) are bacteria lacking a cell wall that cause infections in domestic birds (Figure 1). These organisms continue to cause economic losses in the broiler industry worldwide. Cases complicated by other factors can lead to severe clinical problems or chronic respiratory disease (CRD).

Infections caused by MG can cause rales, cough, runny nose, conjunctivitis, exudates in the air sacs or aerosaculitis (Figure 3), and reductions in growth rates and feeding efficiency. In laying and breeder hens, they can cause drops in production and reductions in the total number of eggs per bird. Breeder cases can also result in high embryonic mortality with lesions in the air sacs.

There is variation in the degree of pathogenicity between MG and MS strains and consequently in the severity of clinical signs. Several factors (Figure 2) can exacerbate the severity of clinical signs:

• Challenges with respiratory viruses (infectious bronchitis, Newcastle disease, avian pneumovirus, avian influenza) and / or immunosuppressants (infection of the bag of Fabricio, infectious anemia, Marek’s disease)
• Respiratory reactions caused by vaccine viruses (Newcastle disease, infectious bronchitis, avian pneumovirus)
• Secondary infections caused by other bacteria ( Ornithobacterium rhinotracheale, E. coli, Pasteurella spp. )
• Adverse environmental conditions (cold temperatures, wet litter, dust, high concentration of ammonia)

Recent cases of MS in breeders have caused dips in egg production, as well as abnormalities in eggshell quality. These abnormalities are located at the apex of the egg and are characterized by rough, thin and more translucent areas of the shell (Figure 5). These problems cause an increase in the number of cracked and broken eggs. These signs usually occur in MS-positive flocks and following outbreaks of infectious bronchitis virus with drops in egg production.