Avian Mycoplasma gallisepticum and Mycoplasma synoviae: Advances in diagnosis and control

Abstract

Both of Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) infections are the most common Mycoplasma infection in domestic poultry. The disease is associated with economic losses in poultry. MG and MS are commonly spread within chickens (Gallus gallus domesticus) and turkeys (Meleagris gallopavo domesticus) flocks; however, they are frequently isolated from quails (Coturnix coturnix) and several avian species. Diagnosis of MG or MS infections is confirmed by isolating the organism in a cell-free medium or directly detecting its DNA in infected tissues or swab samples. Serological tests are also widely used for diagnosis. However, advances in molecular biology represented a rapid and sensitive alternative to the traditional culture methods requiring specialized techniques and sophisticated reagents. Several Mycoplasma molecular diagnostic tests are implemented: including polymerase chain reaction (PCR), Random Amplified Polymorphic DNA (RAPD), arbitrary primed polymerase chain reactions (AP‐PCR), and Multiplex real-time polymerase chain reaction (Multiplex MGMS). Current control practices against Mycoplasma infection include intense biosecurity, biosurveillance, medication, and vaccination. However, the egg-borne nature of avian Mycoplasma infection complicates controlling the infection. This review focuses on the advances in diagnosis and control of avian Mycoplasma infection, especially MG and MS infections.

Infection, Transmission, Pathogenesis and Vaccine Development against Mycoplasma gallisepticum

“…M. gallisepticum follows two routes for transmission—either by transovarian (vertical) transmission or by lateral entry through direct contact (horizontal transmission) [ 21 ].…”

“…The isolation of the organism in a cell-free medium or direct detection of its DNA in infected tissues or swab samples are the two methods used to confirm the diagnosis of MG infection. The use of serological testing for diagnosis is also common [ 21 ]. As a confirmatory test, hemagglutination-inhibition is performed because nonspecific false agglutination reactions might happen, particularly following the injection of inactivated oil-emulsion vaccines or infection with M. synoviae.…”

“…It also causes infection in other birds including peafowl [ 16 ], Japanese quail [ 17 ], bobwhite quail, pigeons, ducks and geese [ 18 ], yellow-naped Amazon parrots, greater flamingos, and peregrine falcons [ 19 , 20 ]. MG in chickens not only causes CRD but also opens the way for other co-infecting pathogens, such as E. coli , and low pathogenic avian influenza subtype H9N1, causing severe economic losses [ 21 ].…”

A novel high sensitive, specificity duplex enzyme-activated differentiating probes PCR method for the SNP detection and differentiation of MS-H vaccine strains from wild-type Mycoplasma synoviae strains

“…Accurate detection is the prerequisite for elimination and cleansing of MS. The gold standard method for diagnosing MS is through isolation and culture, which can be laborious, difficult, and time-consuming ( Abdelrahman et al, 2021 ) due to the slow growth speed of mycoplasma and the demanding culture environment required. Serologic diagnosis of MS can be prone to cross-reaction and have poor specificity and sensitivity ( Ali et al, 2015 ).…”

Seroprevalence of Mycoplasma gallisepticum in Commercial Broiler Chickens in Duhok Governorate

“…Medication can assist to prevent clinical signs and lesions [28]. The eradication of organisms from breeding flocks and their progeny has been the mainstay of MG control, with periodic serological monitoring, followed by culture and/or PCR monitoring, confirming the flocks' Mycoplasma-free status [12,29,30].…”