Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide


avian mycoplasmosis (Mycoplasma gallisepticum)



avian mycoplasmosis (Mycoplasma gallisepticum)


  • Last modified
  • 23 June 2017
  • Datasheet Type(s)
  • Animal Disease
  • Preferred Scientific Name
  • avian mycoplasmosis (Mycoplasma gallisepticum)
  • Overview
  • Four Mycoplasma species are recognised as pathogens of avian hosts, although more than 23 different Mycoplasma species have been recovered from birds. Mycoplasma gallisepticum is the pathogen addressed in thi...

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Preferred Scientific Name

  • avian mycoplasmosis (Mycoplasma gallisepticum)

International Common Names

  • English: avian mycoplasma gallisepticum infection; avian mycoplasmosis; chronic respiratory disease of chickens; infectious sinusitis of turkeys; mycoplasmosis, avian

English acronym

  • CRD


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Four Mycoplasma species are recognised as pathogens of avian hosts, although more than 23 different Mycoplasma species have been recovered from birds. Mycoplasma gallisepticum is the pathogen addressed in this datasheet, but Mycoplasma synoviae may be seen in chickens and turkeys in association with synovitis and/or airsacculitis; Mycoplasma iowae may occur in several hosts but it is normally associated with mortality of turkey embryos but can give rise to joint and bone abnormalities and occasional airsacculitis; Mycoplasma meleagridis is usually found in turkeys causing airsacculitis, poor growth and skeletal abnormalities in progeny, and it has been associated with poor hatchability. M. gallisepticum causes chronic respiratory disease of domestic poultry, especially in the presence of management stresses and/or other respiratory pathogens. Disease is characterised by coryza, conjunctivitis, sneezing, and by sinusitis, particularly in turkeys and game birds. It can result in loss of production and downgrading of meat-type birds, and loss of egg production.

Mycoplasma gallisepticum and Mycoplasma synoviae are on the World Organisation for Animal Health (OIE) list of economically important diseases and infections are notifiable to them. The EU Directive 2009/198 includes Mycoplasma gallisepticum and Mycoplasma meleagridis and relates to animal health conditions governing intra-Community trade and imports from third countries of poultry and hatching eggs.

Mycoplasma gallisepticum (Mg) is the most economically significant mycoplasma pathogen of poultry and has a world-wide distribution (Levisohn and Kleven, 2000). Infection with Mg may manifest in different ways but chronic respiratory disease (CRD) and downgrading of carcasses in meat-type birds is probably the most severe forms. Mg is often one of the aetiological agents in a multi-factorial disease complex, which may include respiratory viruses, Escherichia coli, Haemophilusparagallinarum and other bacteria. Loss of egg production in laying birds may occur and is usually most marked at peak laying times. Conjunctivitis and sinusitis may occur with severe infections causing inflammation of the tissues around the eyes resulting in a swollen distorted face. Mg is transmitted both vertically from hen to progeny through the egg (in ovo), through the semen of infected roosters; and horizontally by the respiratory route. Mg has been reported in wild birds, particularly as a cause of conjunctivitis in house finches (Carpodacus mexicanus) in North America where the disease emerged in 1994 (Ley et al., 2006).

Antimicrobial treatment may reduce the impact of the disease, but can not be relied upon to eliminate the disease. Good biosecurity and obtaining birds from Mg free stock is a good way of preventing diseases. Some live attenuated vaccines are available, but some questions about their effectiveness and ability to cause disease still need to be addressed.

The Mycoplasma species that occur in avian host species are not zoonotic. 

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes


AfghanistanNo information availableOIE, 2009
ArmeniaDisease not reportedOIE, 2009
AzerbaijanDisease not reportedOIE, 2009
BahrainDisease not reportedOIE, 2009
BangladeshPresentOIE, 2009
BhutanDisease not reportedOIE, 2009
Brunei DarussalamNo information availableOIE Handistatus, 2005
CambodiaNo information availableOIE, 2009
ChinaNo information availableOIE, 2009
-Hong KongNo information availableOIE, 2009
Georgia (Republic of)Disease never reportedOIE Handistatus, 2005
IndiaRestricted distributionOIE, 2009
IndonesiaDisease not reportedOIE, 2009
IranDisease not reportedOIE, 2009
IraqPresentOIE, 2009
IsraelPresentOIE, 2009
JapanDisease not reportedOIE, 2009
JordanPresentOIE, 2009
KazakhstanDisease not reportedOIE, 2009
Korea, DPRDisease not reportedOIE Handistatus, 2005
Korea, Republic ofPresentOIE, 2009
KuwaitDisease not reportedOIE, 2009
KyrgyzstanDisease not reportedOIE, 2009
LaosDisease not reportedOIE, 2009
LebanonAbsent, reported but not confirmedOIE, 2009
MalaysiaDisease not reportedOIE, 2009
-Peninsular MalaysiaNo information availableOIE Handistatus, 2005
-SabahLast reported2002OIE Handistatus, 2005
-SarawakSerological evidence and/or isolation of the agentOIE Handistatus, 2005
MongoliaNo information availableOIE, 2009
MyanmarPresentOIE, 2009
NepalPresentOIE, 2009
OmanPresentOIE, 2009
PakistanPresentOIE, 2009
PhilippinesNo information availableOIE, 2009
QatarNo information availableOIE, 2009
Saudi ArabiaNo information availableOIE, 2009
SingaporeDisease not reportedOIE, 2009
Sri LankaDisease not reportedOIE, 2009
SyriaNo information availableOIE, 2009
TaiwanReported present or known to be presentOIE Handistatus, 2005
TajikistanDisease not reportedOIE, 2009
ThailandDisease not reportedOIE, 2009
TurkeyNo information availableOIE, 2009
TurkmenistanNo information availableOIE Handistatus, 2005
United Arab EmiratesNo information availableOIE, 2009
UzbekistanReported present or known to be presentOIE Handistatus, 2005
VietnamNo information availableOIE, 2009
YemenNo information availableOIE, 2009


AlgeriaNo information availableOIE, 2009
AngolaNo information availableOIE, 2009
BeninNo information availableOIE, 2009
BotswanaPresentOIE, 2009
Burkina FasoNo information availableOIE, 2009
BurundiNo information availableOIE Handistatus, 2005
CameroonNo information availableOIE Handistatus, 2005
Cape VerdeReported present or known to be presentOIE Handistatus, 2005
Central African RepublicNo information availableOIE Handistatus, 2005
ChadNo information availableOIE, 2009
CongoNo information availableOIE, 2009
Congo Democratic RepublicNo information availableOIE Handistatus, 2005
Côte d'IvoireReported present or known to be presentOIE Handistatus, 2005
DjiboutiDisease not reportedOIE, 2009
EgyptDisease not reportedOIE, 2009
EritreaNo information availableOIE, 2009
EthiopiaNo information availableOIE, 2009
GabonDisease not reportedOIE, 2009
GambiaNo information availableOIE, 2009
GhanaDisease not reportedOIE, 2009
GuineaNo information availableOIE, 2009
Guinea-BissauNo information availableOIE, 2009
KenyaDisease not reportedOIE, 2009
LesothoDisease not reportedOIE, 2009
LibyaReported present or known to be presentOIE Handistatus, 2005
MadagascarDisease not reportedOIE, 2009
MalawiPresentOIE, 2009
MaliNo information availableOIE, 2009
MauritiusDisease not reportedOIE, 2009
MoroccoNo information availableOIE, 2009
MozambiquePresentOIE, 2009
NamibiaDisease not reportedOIE, 2009
NigeriaDisease not reportedOIE, 2009
RéunionNo information availableOIE Handistatus, 2005
RwandaNo information availableOIE, 2009
Sao Tome and PrincipeNo information availableOIE Handistatus, 2005
SenegalNo information availableOIE, 2009
SeychellesDisease not reportedOIE Handistatus, 2005
SomaliaNo information availableOIE Handistatus, 2005
South AfricaDisease not reportedOIE, 2009
SudanDisease not reportedOIE, 2009
SwazilandDisease not reportedOIE, 2009
TanzaniaNo information availableOIE, 2009
TogoNo information availableOIE, 2009
TunisiaPresentOIE, 2009
UgandaNo information availableOIE, 2009
ZambiaNo information availableOIE, 2009
ZimbabweDisease not reportedOIE, 2009

North America

BermudaDisease not reportedOIE Handistatus, 2005
CanadaPresentOIE, 2009
GreenlandDisease never reportedOIE, 2009
MexicoPresentOIE, 2009
USARestricted distributionOIE, 2009

Central America and Caribbean

BarbadosReported present or known to be presentOIE Handistatus, 2005
BelizeDisease not reportedOIE, 2009
British Virgin IslandsDisease not reportedOIE Handistatus, 2005
Cayman IslandsDisease not reportedOIE Handistatus, 2005
Costa RicaPresentOIE, 2009
CubaPresentOIE, 2009
CuraçaoDisease not reportedOIE Handistatus, 2005
DominicaDisease not reportedOIE Handistatus, 2005
Dominican RepublicPresentOIE, 2009
El SalvadorNo information availableOIE, 2009
GuadeloupeNo information availableOIE, 2009
GuatemalaDisease not reportedOIE, 2009
HaitiNo information availableOIE, 2009
HondurasDisease never reportedOIE, 2009
JamaicaDisease not reportedOIE, 2009
MartiniquePresentOIE, 2009
NicaraguaNo information availableOIE, 2009
PanamaNo information availableOIE, 2009
Saint Kitts and NevisDisease never reportedOIE Handistatus, 2005
Saint Vincent and the GrenadinesDisease never reportedOIE Handistatus, 2005
Trinidad and TobagoNo information availableOIE Handistatus, 2005

South America

ArgentinaPresentOIE, 2009
BoliviaRestricted distributionOIE, 2009
BrazilPresentOIE, 2009
ChileRestricted distributionOIE, 2009
ColombiaDisease not reportedOIE, 2009
EcuadorDisease not reportedOIE, 2009
Falkland IslandsDisease not reportedOIE Handistatus, 2005
French GuianaDisease not reportedOIE, 2009
GuyanaSerological evidence and/or isolation of the agentOIE Handistatus, 2005
ParaguayNo information availableOIE Handistatus, 2005
PeruRestricted distributionOIE, 2009
UruguayPresentOIE, 2009
VenezuelaDisease not reportedOIE, 2009


AlbaniaNo information availableOIE, 2009
AndorraNo information availableOIE Handistatus, 2005
AustriaNo information availableOIE, 2009
BelarusDisease never reportedOIE, 2009
BelgiumDisease not reportedOIE, 2009
Bosnia-HercegovinaDisease not reportedOIE Handistatus, 2005
BulgariaNo information availableOIE, 2009
CroatiaDisease not reportedOIE, 2009
CyprusDisease not reportedOIE, 2009
Czech RepublicDisease not reportedOIE, 2009
DenmarkDisease not reportedOIE, 2009
EstoniaDisease not reportedOIE, 2009
FinlandDisease not reportedOIE, 2009
FranceNo information availableOIE, 2009
GermanyDisease not reportedOIE, 2009
GreeceRestricted distributionOIE, 2009
HungaryDisease not reportedOIE, 2009
IcelandDisease not reportedOIE, 2009
IrelandDisease not reportedOIE, 2009
Isle of Man (UK)No information availableOIE Handistatus, 2005
ItalyNo information availableOIE, 2009
JerseyDisease never reportedOIE Handistatus, 2005
LatviaDisease not reportedOIE, 2009
LiechtensteinDisease not reportedOIE, 2009
LithuaniaDisease not reportedOIE, 2009
LuxembourgDisease not reportedOIE, 2009
MacedoniaAbsent, reported but not confirmedOIE, 2009
MaltaDisease not reportedOIE, 2009
MoldovaDisease not reportedOIE Handistatus, 2005
MontenegroDisease not reportedOIE, 2009
NetherlandsPresentOIE, 2009
NorwayPresentOIE, 2009
PolandPresentOIE, 2009
PortugalDisease not reportedOIE, 2009
RomaniaDisease not reportedOIE, 2009
Russian FederationPresentOIE, 2009
SerbiaDisease not reportedOIE, 2009
SlovakiaDisease not reportedOIE, 2009
SloveniaDisease not reportedOIE, 2009
SpainRestricted distributionOIE, 2009
SwedenPresentOIE, 2009
SwitzerlandDisease not reportedOIE, 2009
UKPresentOIE, 2009
-Northern IrelandReported present or known to be presentOIE Handistatus, 2005
UkraineDisease not reportedOIE, 2009
Yugoslavia (former)No information availableOIE Handistatus, 2005
Yugoslavia (Serbia and Montenegro)Disease not reportedOIE Handistatus, 2005


AustraliaPresentOIE, 2009
French PolynesiaPresentOIE, 2009
New CaledoniaPresentOIE, 2009
New ZealandPresentOIE, 2009
SamoaDisease never reportedOIE Handistatus, 2005
VanuatuDisease not reportedOIE Handistatus, 2005
Wallis and Futuna IslandsNo information availableOIE Handistatus, 2005


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The gross lesions of the respiratory tract may be mild and only consist of excess mucus or catarrhal exudate in the nares, trachea and lungs and oedema in the airsac walls. Caseous exudate may appear later in the airsacs or attached to their walls. Dilation of the infraorbital sinuses, particularly in turkeys, may be initially caused by mucus which may then be replaced by caseous material. In disease exacerbated by other pathogens, the lesions are more severe, pericarditis and perihepatitis may accompany the lesions of the airsacs and upper respiratory tract (Blaxland et al., 1982).

Encephalopathy can occur particularly in turkeys, but usually no gross lesions are visible. In salpingitis cases, caseous exudate occurs in the oviduct.


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Clinical signs, post mortem and histological lesions are not pathognomic for Mg. Isolation of the causative organism is the definitive confirmation of infection, but this requires mycoplasma culture media and incubation of cultures for three to four weeks. Specificity of the diagnostic tests does present some difficulties as birds are often infected with more than one mycoplasma species, sometimes as many as five Mycoplasma species have been detected in one sample; and many of these are considered to be non-pathogenic mycoplasmas, which may give a false negative or false positive result. Surveillance for clinical signs and lesions of mycoplasma infection must be ongoing. Testing should be carried out on a statistical representative number of birds in a flock and birds should be sampled at random from each part of the flock.

Serological detection of antibodies is recognised as a way of monitoring flocks and detection of disease, but this usually also requires confirmation by other diagnostic methods along with veterinary diagnosis of clinical signs in the flock. The haemagglutination-inhibition (HI) test is rarely used now, but is still a prescribed test listed in the OIE terrestrial manual. More commonly used is the rapid/serum plate agglutination test or rapid slide agglutination test. This is a flock test as the test does give some false reactions. The early guidelines were that 60 serum samples should be taken per house and a flock was only considered positive when more than 15% of the undiluted samples were positive or more than 3% with a titre of more than 1:8 (Intervet information sheet). However different manufacturers now make this test and the sensitivity and specificity may vary with between manufacturers and different batches of the antigen. The test is simple to perform, but manufacturer’s instructions should be followed and appropriate positive and negative control serum tested. Essentially the antigen and serum to be tested should be allowed to warm to 20-25°C. Equal volumes of the serum and the antigen are mixed for two minutes and any agglutination observed recorded as positive. Dilutions of sera should be tested to resolve any doubts about a positive test result. Only fresh sera should be tested.

More recently several manufacturers are producing ELISA tests and these are designed for laboratory use. These are generally a flock based test and users should be aware that some differences in test performance and batches do occur.

A species-specific confirmatory serological test using a Western blot/immunoblot method has been developed (Welchman et al., 2013).

Antigen detection using molecular tests have been developed, they are mainly polymerase chain reaction (PCR) based tests. A PCR method for detecting Mg is given in the OIE Manual (OIE, 2012), but many other methods have been published as referenced in Kleven (2008). A PCR method using the 16S rDNA gene followed by the use of denaturing gradient gel electrophoresis has been able to detect and identify the majority of Mycoplasma species including Mg. This test is sensitive and will identify all of the Mycoplasma species that affects avian species in one test and will also detect and identify mixed infections (McAuliffe et al., 2005).

Samples to be tested can be swabs from live birds or swabs/tissues from carcases. Tracheal, choanal, or air sacs swabs are tested. The same samples can be used for mycoplasma culture.

No single medium formulation has been accepted as optimum for growth of Mg. Mg ferments glucose and requires 10-15% horse or swine serum, and a yeast source to provide nutrients (Kleven, 2008). Broth culture is usually more sensitive than agar but both agar and broth are inoculated at the same time and incubated at 37°C ideally for growth on agar with an additional 5-10% CO2 in a humid environment. Bradbury (1998a) describes methods to recover mycoplasma s from birds and gives details of suitable media formulations. Mg will ferment glucose producing an acid pH in the broth media and typical “fried egg” colonies can be observed on agar using a microscope under low magnification (approx 35X magnification). Mixed cultures are often obtained and identification need to be confirmed either by molecular methods or using a specific Mg antiserum in a growth inhibition test (Poveda and Nicholas, 1998) or using immuno-fluorescence antibody test (Bradbury 1998b).

List of Symptoms/Signs

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SignLife StagesType
Digestive Signs / Anorexia, loss or decreased appetite, not nursing, off feed Sign
General Signs / Lack of growth or weight gain, retarded, stunted growth Sign
General Signs / Lameness, stiffness, stilted gait in birds Sign
General Signs / Orbital, periorbital, periocular, conjunctival swelling, eyeball mass Sign
General Signs / Swelling of the limbs, legs, foot, feet, in birds Sign
General Signs / Torticollis, twisted neck Sign
General Signs / Underweight, poor condition, thin, emaciated, unthriftiness, ill thrift Sign
General Signs / Weight loss Sign
Musculoskeletal Signs / Abnormal curvature, angulation, deviation of legs, limbs, feet of birds Sign
Nervous Signs / Dullness, depression, lethargy, depressed, lethargic, listless Sign
Ophthalmology Signs / Chemosis, conjunctival, scleral edema, swelling Sign
Ophthalmology Signs / Conjunctival, scleral, injection, abnormal vasculature Sign
Ophthalmology Signs / Conjunctival, scleral, redness Sign
Ophthalmology Signs / Lacrimation, tearing, serous ocular discharge, watery eyes Sign
Ophthalmology Signs / Purulent discharge from eye Sign
Reproductive Signs / Decreased, dropping, egg production Sign
Respiratory Signs / Abnormal lung or pleural sounds, rales, crackles, wheezes, friction rubs Sign
Respiratory Signs / Coughing, coughs Sign
Respiratory Signs / Dyspnea, difficult, open mouth breathing, grunt, gasping Sign
Respiratory Signs / Increased respiratory rate, polypnea, tachypnea, hyperpnea Sign
Respiratory Signs / Mucoid nasal discharge, serous, watery Sign
Respiratory Signs / Purulent nasal discharge Sign

Disease Course

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Mycoplasma gallisepticum infections vary from asymptomatic to severe depending on the infecting strain and other factors. More severe infections are seen when the birds are infected concurrently with other bacterial or viral pathogens, including Escherichia coli, Newcastle disease virus or infectious bronchitis virus. Infected birds initially develop respiratory signs that may include rales, coughing, sneezing, nasal discharges and dyspnea. Turkeys may present with more severe clinical signs which includes swelling of the infraorbital sinus. Conjunctivitis with a frothy ocular exudate occurs more frequently in turkeys, but does also occur in chickens. The route of exposure and the infectious dose of Mg, in addition to environmental and stress factors such as temperature and ammonia concentration, age and type of birds are factors that influence the course of the disease (In: Levisohn and Kleven, 2000). Production is lower in infected flocks, with decreased weight gain, feed efficiency and egg production. In chickens with uncomplicated infections the morbidity rate is high and the mortality rate low; however more severe disease occurs when the birds are co-infected with other pathogens. Mortality rates in turkeys are generally higher than in chickens. Mg has been implicated in salpingitis and other pathologies of the reproductive system, but it is not clear if this is the main or sole cause of reduction in egg production (Nunoya et al., 1997) which is particularly noticeable at times of peak lay.


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Mycoplasma gallisepticum is in the Class Mollicutes which are phenotypically distinguished from other bacteria by their minute size and total lack of a cell wall. They have a small genome size (996?422 bp for Rlow strain (Papazisi et al., 2003)) which accounts for their complex nutritional requirements and its obligate parasitic mode of life.

The primary habitats of mycoplasmas in general are the mucosal membranes of the respiratory tract, and/or the urogenital tract, eyes, mammary glands and joints (Levisohn and Kleven, 2000). Mg is one of the species of mycoplasma that can cause acute and chronic diseases at multiple sites, but is usually seen as a parasite of the airways of affected avian species. Uncontrolled proliferation of the organism in susceptible birds causes severe inflammation of the mucosa of the sinuses and/or trachea, and infection extends to the lungs and air sacs (Browning et al., 2010).

Transfer of the organism from hen to progeny through the eggs is an important means of spread in poultry. It is therefore important to source poults or chicks from Mg free breeding stock. Introduction of older birds into a flock can present a significant risk of introducing Mg, especially if purchased from mixed sources or through markets. Any stress, including the social stress of mixing birds together can precipitate an apparent healthy but infected bird to start shedding the organism. Direct spread from bird to bird via the respiratory route can occur readily, as well as on fomites, but spread within a flock is generally slow with an incubation period of 6 to 21 days. It is thought that an infection may persists for 18 months or even longer, but survival outside of the host under farm conditions was thought to be unlikely to exceed a few days, although Mg’s ability to form a biofilm may mean they can survive longer (Chen et al., 2013). Biosecurity is important to prevent spread from flock to flock, or farm to farm, as the organism can be carried and transmitted through contaminated footwear, clothing or equipment. The role of wild birds as a reservoir of disease and their role in transmitting Mg has been highlighted since the reports of Mg in house finches (Ley et al., 1996). If a flock becomes infected a complete depopulation followed by clean out and sanitization of the premises is required to ensure the disease is eliminated.

Despite its small genome Mg is genetically quite variable as it possesses between 30 and 70 variant vlhA genes, most of which are translationally competent (Baseggio et al., 1996). These genes have probably been acquired by lateral gene transfer between Mycoplasma species, but only one gene appears to be transcribed at a time, so only a single variant of this lipoprotein is expressed on the cell surface at any one time (Browning et al., 2010). This gene expression may change after initial infection, suggesting it has an initial role in adherence, but then the antigenic variation helps the organism evade the host’s immune response (Browning et al., 2010). Several approaches to molecular epidemiological typing have been used to differentiate isolates. Feberwee et al. (2005) used amplified fragment length polymorphism (AFLP) and random amplified polymorphic DNA (RAPD) analysis to give five clusters of Mg. Sprygin et al. (2010) demonstrated that Russian Mg isolates clustered more closely to each other than to isolates from USA, Australia, China and Iran using partial sequencing of a pvpA gene fragment. Ghorashi et al. (2010) used a PCR of the vlhA gene and high-resolution melting curve analysis to differentiate 10 Mg strains which included the ability to differentiate three vaccine strains.

Impact: Economic

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Mycoplasma gallisepticum is believed to cost the worldwide poultry industry over US $780 million every year. Loss of egg production in the United States is believed to cost over US $120 million, without the cost of culling and restocking infected flocks to prevent further spread (Hennigana et al., 2011). Serious economic losses are also incurred through reduced growth production, carcass condemnations, and retarded growth in juveniles. Also, chickens have been documented to lose about 16 eggs over their laying cycle of 45 weeks (Peebles et al., 2012).

Earlier Mohammed et al. (1987) estimated 127 million eggs were lost during an Mg infection in 1984 in Southern California, with a financial loss of US $7 million

Zoonoses and Food Safety

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Mycoplasma gallisepticum is not a zoonotic pathogen as it only infects avian species.

Prevention and Control

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Prevention of disease by ensuring birds are acquired from an Mg free source is the most effective approach to prevent introduction of disease into a flock. However biosecurity and sanitation are essential to prevent the spread of Mg into a susceptible flock. Biosecurity should keep wild birds away from the flock and visitor access to the flock should be restricted and strict sanitation procedures should be followed, with no equipment being shared with other bird owners, or thorough cleaning and disinfection applied. When a flock has been removed a thorough cleaning and disinfection should be carried out. If a flock has become infected then depopulation and an extended down time with thorough cleansing and disinfection should be instigated before repopulating from a clean source.

Mg is generally susceptible to a number of antibiotics, however antibiotic resistance is increasingly being reported and it is known that most antibiotics just suppress the clinical signs and do not eliminate the infection. Antibiotics that should be effective include the macrolides, tetracyclines, spectiniomycin, lincomycin and fluoroquinolones (Salami et al., 1992). However Gharaibeh and Al-Rashdan (2011) reported resistance to 8 antibiotics in three families of antibiotics and Gerchman et al. (2008) reported resistance to the fluoroquinolone enrofloxacin. Soaking of infected eggs in antibiotics may prevent the transfer of Mg infection in ovo, but it may reduce egg hatchability (Hall et al., 1963).

Inactivated bacterins have proved to be efficacious in some cases in reducing respiratory signs and lesions in chickens and reducing egg production losses and transmission, however other studies have shown minimal or no effect (Levisohn and Kleven, 2000). Three live Mg vaccines are available in different countries in the world. These are the F strain; 6/85 and ts-11, although not all countries officially permit use of live vaccines (Levisohn and Kleven, 2000). Some vaccines are for use in chickens only while others can also be used in turkeys. Some debate continues about the use of live vaccines, as some reports exist of introduction of disease into flocks by using the vaccines, whilst others report that the wild strain is eliminated by use of the vaccine. Feberwee et al. (2006) reported reduction in Mg infection but insufficient to prevent spread of disease. Ideally flocks should be kept free of Mg.

Mg is an OIE listed disease even though it occurs worldwide. The EU Directive 2009/198 includes Mycoplasma gallisepticum and Mycoplasma meleagridis and relates to animal health conditions governing intra-community trade and imports from third countries of poultry and hatching eggs.


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Baseggio N; Glew MD; Markham PF; Whithear KG; Browning GF, 1996. Size and genomic location of the pMGA multigene family of Mycoplasma gallisepticum. Microbiology (Reading), 142(6):1429-1435.

Blaxland JD; Cullen GA; Gordon RF; Jordan FTW, 1982. Diseases caused by bacteria, mycoplasmas and chlamydia. In: Gordon RF, Jordan FTW, eds. Poultry Diseases. London, UK: Bailliere Tindall, 62-75.

Bradbury JM, 1998a. Recovery of mycoplasmas from birds. In: Miles R, Nicholas R eds. Mycoplasma Protocols. Totowa, USA: Humana Press, 45-52.

Bradbury JM, 1998b. Identification of mycoplasmas by immunofluorescence. In: Miles R, Nicholas R, eds. Mycoplasma Protocols. Totowa, USA: Humana Press, 119-126.

Browning GF; Marenda MS; Markham PF; Noormohammadi AH; Whitear KG, 2010. Mycoplasma. In: Pathogenesis of Bacterial Infections in Animals, 4th Edition [ed. by Gyles, C. L. \Prescott, J. F. \Songer, J. G. \Thoen, C. O.]. Ames, Iowa, USA: Blackwell Publishing Professional, 549-573.

Chen HongJun; Yu ShengQing; Hu MeiRong; Han XianGan; Chen DanQing; Qiu XuSheng; Ding Chan, 2013. Identification of biofilm formation by Mycoplasma gallisepticum. Veterinary Microbiology, 161(1/2):96-103.

Feberwee A; Dijkstra JR; Banniseht-Wysmuller TEvon; Gielkens ALJ; Wagenaar JA, 2005. Genotyping of Mycoplasma gallisepticum and M. synoviae by Amplified Fragment Length Polymorphism (AFLP) analysis and digitalized Random Amplified Polymorphic DNA (RAPD) analysis. Veterinary Microbiology, 111(1/2):125-131.

Feberwee A; Landman WJM; Banniseht-Wysmuller Tvon; Klinkenberg D; Vernooij JCM; Gielkens ALJ; Stegeman JA, 2006. The effect of a live vaccine on the horizontal transmission of Mycoplasma gallisepticum. Avian Pathology, 35(5):359-366.

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Gharaibeh S; Al-Rashdan M, 2011. Change in antimicrobial susceptibility of Mycoplasma gallisepticum field isolates. Veterinary Microbiology, 150(3/4):379-383.

Ghorashi SA; Noormohammadi AH; Markham PF, 2010. Differentiation of Mycoplasma gallisepticum strains using PCR and high-resolution melting curve analysis. Microbiology (Reading), 156(4):1019-1029.

Glasgow LR; Hill RL, 1980. Interaction of Mycoplasma gallisepticum with sialyl glycoproteins. Infection and Immunity, 30(2):353-361.

Hall CF; Flowers AI; Grumbles LC, 1963. Dipping of hatching eggs for control of Mycoplasma gallisepticum. Avian Diseases, 7:178-183.

Hennigan SL; Driskell JD; Ferguson-Noel N; Dluhy RA; Zhao YP; Tripp RA; Krause DC, 2012. Detection and differentiation of avian mycoplasmas by surface-enhanced raman spectroscopy based on a silver nanorod array. Applied and Environmental Microbiology, 78(6):1930-1935.

Indikova I; Vronka M; Szostak MP, 2014. First identification of proteins involved in motility of Mycoplasma gallisepticum. Veterinary Research, 45(99):(17 October 2014).

Kleven SH, 2008. Mycoplasmosis. In: A laboratory manual for the isolation, identification and characterization of avian pathogens, 5th Edition [ed. by Dufour-Zavala, L. \Swayne, D. E. \Glisson, J. R. \Pearson, J. E. \Reed, W. M. \Jackwood, M. W. \Woolcock, P. R.]., USA: American Association of Avian Pathologists, 59-64.

Levisohn S; Kleven SH, 2000. Avian mycoplasmosis (Mycoplasma gallisepticum). Revue Scientifique et Technique - Office International des Épizooties [Special issue. Diseases of poultry: world trade and public health implications.], 19(2):425-442.

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