Mycoplasma synoviae

From MicrobeWiki, the student-edited microbiology resource

A Microbial Biorealm page on the genus Mycoplasma synoviae

Classification

Higher order taxa

Bacteria; Firmicutes; Mollicutes; Mycoplasmataceae; mycoplasma

Species

Mycoplasma synoviae

Description and significance

Mycoplasma synoviae is a parasite responsible for causing respiratory tract disease and synovitis in turkeys and chickens, although other types of birds are susceptible as well. Naturally, this causes significant economic problems in the poultry industry. The primary habitat is the mucous membranes of the respiratory tract of the birds that are infected. Infection that occurs through attachment of the bacteria to the host cell by means of specialized surface proteins and adhesins results in prolonged intracellular persistence that may cause lethality.

Genome structure

Mycoplasma synoviae has one circular chromosome that is made up of 799, 476 bp with a total of 694 ORFs. There are 672 protein genes and 41 RNA genes. This information is based on mycoplasma synoviae strand 53, which was isolated from a broiler breeder pig from Brazil

Cell structure and metabolism

Like all mycoplasma, mycoplasma synoviae is distinguishable by its small size (0.3-0.8 microns in diameter) as well as its lack of a cell wall. The cell membrane is rich in protein components that consists of lipoproteins that work to attach the cell to a host. It is also non-motile due to the lack of flagella. Because it is lacking codng genes for components of energy metabolism it is mostly dependent on glycolysis in order to produce ATP. It specifically requires nicotinamide adenine dinucleotide (NAD) in artificial culture.

Ecology

Mycoplasma synoviae can be transmitted by the respiratory route or by egg transmission and colonize primarily in the respiratory systems of birds such as chickens and turkeys. It has been determined that chickens are more susceptible than turkeys to the pathogen. Other birds cannot acquire the pathogen by natural means, though intravenous inoculation can cause pheasants and geese to be affected. Ducks and other specimens of birds seem to be unaffected by the pathogen.

This pathogen is significant because it reduces optimal production, raises food conversion rates, and leads to downgrading of carcasses in poultry. There is also reason to believe that it can lead to a reduced egg production and a lowered rate of viable hatching chicks, though evidence is sketchy at best for now.

Pathology

Mycoplasma synoviae does not cause any lethal diseases alone. What it does do though is contribute to the destabilization of the immune system to allow secondary infections such as bacterial bronchitis to develop respiratory syndromes of severe impact such as respiratory lesions. The infection appears to be worldwide, though it is only prevalent in chickens and turkeys, although other types of birds can contract it under experimental conditions. Symptoms include swollen feet, ruffled feathers, and inappetance. It is also very likely that there are no noticable symptoms at all, in which case the only possible way to detect the pathogen is via a blood sample. Another prominient symptom is arthritis, which can persist even when other symptoms have faded away. Affect on egg production is low, but it is likely to spread by means of egg transmission.

A prominent difference between Mycoplasma synoviae and the similar pathogen Mycoplasma gallisepticum is that the first tends to infiltrate other organs of the chicken's body, while the latter does not. Examples include the heart, liver, and spleen. Another prominent symptom is arthritis, which can persist even when other symptoms have faded away. Additionally, mycoplasma synoviae acts together with other viruses to also cause air sacculitis in chickens and turkeys. Air sacculitis causes inflammation of the air sacs that all birds have.

Application to Biotechnology

Thus far, it seems that the only benefit of Mycoplasma synoviae is that those birds that recover from infection seem to be resistant to foot pad challenge, meaning that their legs had become stronger than before.

Current Research

1) The first study was done to analyse the indirect transmission properties of mycoplasma synoviae. Chickens were introduced to an insolated area that was previously contaminated by mycoplasma synoviae broth culture. 34 days later, these birds were eliminated and replaced by healthy chicks without disinfecting. Chicks were also placed in an isolated area containing food, feathers, and dust that came from an infected laying hen flock. In all three situations, the chicks contracted the pathogen but it took longer for the chicks that were in the habitat containing infected food, feathers, and dust. It was determined that mycoplasma synoviae could be transferred indirectly and contaminated materials, such as feathers, food, and dust, that can infect chicks even after remarkably long silent periods.

2) A quick, qualitative test to determine the presence of mycoplasma synoviae was found by means of the Rapid Slide Agglutination (RPA) Test. This test is used to determine the presence of antibodies in serum from potentaially infected birds that react with the mycoplasma synoviae antigens.

3) Short nucleotides directly labeled to alkaline phosphatase (also known as SNAP probe) has been seen as an alternative in detecting the presence of mycoplasma synoviae because they have less steps required in dot blots in order to detect DNA or amplificate.

References

Vasconcelos, AT. "Genome Project > Mycoplasma Synoviae 53 Project At LNCC - Laboratorio Nacional De Computacao Cientifica." NCBI. 18 Aug. 2005. PubMed. 2 May 2007 <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=genomeprj&cmd=Retrieve&dopt=Overview&list_uids=10676>.

Gattiker, Alexandre. "HAMAP: Mycoplasma Synoviae (Strain 53) Complete Proteome." ExPASy. 7 Nov. 2002. Swiss Institute of Bioinformatics. 2 May 2007 <http://expasy.org/sprot/hamap/MYCS5.html>.

McMullin, Paul. "Mycoplasma Synoviae Infection, M.S. Infectious Synovitis." ThePoultrySite.Com. 1 Jan. 2004. 5M Enterprises Ltd. 2 May 2007 <http://www.thepoultrysite.com/diseaseinfo/99/mycoplasma-synoviae-infection-ms-infectious-synovitis>. http://www.brgene.lncc.br/finalMS/

Picault, JP, C Marois, M Kobisch, and I Kempf. "Experimental Evidence of Indirect Transmission of Mycoplasma Synoviae." NCBI. Winter 2005. PubMed. 2 May 2007 <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=16120251&dopt=Abstract>.

Bell, M. "TC0308 Mycoplasma Synoviae Rapid Slide Agglutination (RSA) Test." TDS. Dec. 2004. OIE Manual of standards for Diagnostic Tests and Vaccines 2000. 2 May 2007 <http://www.defra.gov.uk/corporate/vla/lab-test/surv/ltd-tc0308.pdf>.

Salisch, H, M Ryll, R Leise, and U Neumann. "Use of an Alkaline Phosphatase-Labelled Probe for the Detection of Mycoplasma Synoviae in Chickens." Blackwell Synergy. Feb. 2000. Journal of Veterinary Medicine Series B. 2 May 2007 <http://www.blackwell-synergy.com/links/doi/10.1046/j.1439-0450.2000.00312.x/full/>.



Edited by Robert Rishwain