What is Mycoplasma?

board of animal health

Reportable Disease of the Month


What is it?

Mycoplasma is a type of bacteria that can infect and cause disease in a wide variety of animals and people. The mycoplasmas that infect avian species not only can cause disease in commercial chickens and turkeys, but they can also cause disease in other avian species. The Mycoplasmas that are commonly seen in poultry include Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS) and Mycoplasma meleagridis (MM). In poultry, each species of mycoplasma has distinctive disease concerns and exhibit different characteristics, but they have a common route of transmission, which is during the hatching process from hen to chick or poult.

Mycoplasma gallisepticum is the most pathogenic type in poultry, meaning it has a tendency to cause more serious disease. It typically impacts chickens as a chronic respiratory disease with a nasal and ocular (eye) discharge and reduced egg production. In turkeys it results in severe swollen sinuses, coughing and slow, stunted growth. It affects poultry worldwide and is commonly seen in noncommercial flocks including pheasants and other game birds. When large commercial poultry operations are infected, it can cause significant economic losses.

The National Poultry Improvement Plan (NPIP) has programs available that allow participating breeder flocks to demonstrate they are free from infection. The NPIP testing emphasis is focused on breeder flocks to prevent egg transmission (transovarian). In Minnesota, turkey breeder flocks and egg and meat-type chicken breeder flocks are required to participate. Minnesota has been classified as MG Clean for turkeys since 1980 and MG Clean for meat-type chickens since 2003.

Mycoplasma synoviae most commonly impacts chickens and turkeys as upper respiratory infections or joint and tendon infections. It is distributed worldwide and is seen primarily in chickens and turkeys, but gamebirds and waterfowl may also be infected. Minnesota has been classified as MS Clean for turkeys since 2003.

Mycoplasma meleagridis only impacts turkeys. It has been associated with decreased hatchability, poor growth and other skeletal abnormalities. Successful control programs like the NPIP have reduced economic losses associated with the disease. Testing for MM is voluntary, although testing in most turkey breeder flocks is very common.

How is it transmitted?

The most common route of mycoplasma disease spread in the poultry industry is vertically through egg transmission. The bacteria can also move through feed and water contamination, environmental contamination, mechanical transmission on clothing and equipment, and direct contact when flocks or birds are exposed to infected birds. MG, MS and MM are egg transmitted diseases which have the potential to become widespread in a short time period without proper and timely breeder flock surveillance.

What are the clinical signs?

Clinical signs may vary by the mycoplasma type, and in general there are typically few or slight signs in adult birds. Overt signs include reduced hatchability, mild respiratory distress, lameness and depression, mild sinusitis (yellowish discharge of the sinus), swollen joints, and difficulty breathing. Mycoplasma gallisepticum is usually more severe in turkeys, which is why it’s also known as Infectious Sinusitis in turkeys.

How is it diagnosed?

There are a number of different diagnostics tests that can be used to identify Mycoplasma infections in poultry. Mycoplasma is a routine test among participating National Poultry Improvement Plan breeder flocks. Samples are collected and submitted to the Minnesota Poultry Testing Laboratory. Samples are then tested by laboratory staff and results are reported to the flock owner and hatchery.

Is there a risk to people?

There is no known risk to humans, and poultry products are safe to consume. However, people should practice strict biosecurity near poultry flocks because mycoplasma can be a significant disease issue for breeder flocks, hatcheries, poultry producers and poultry processing plants.

How can it be prevented?

A strict biosecurity program that limits or prevents exposure to infected birds or contaminated products, equipment and people is the best way to prevent infection. Mycoplasmas are bacteria that do not survive for more than a few days outside the host and are vulnerable to common disinfectants. Participants in the National Poultry Improvement Plan also help prevent mycoplasma infections by using clean breeder flock sources and meeting flock biosecurity standards.

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