Innovation Europe > News > Innovation EU Vol1-1 > Mycoplasmology

Mycoplasmas – small parasitic bacteria that lack a cell wall and can survive without oxygen – can cause pneumonia and other infections in a wide range of hosts, including plants, insects, birds, animals and humans. They cause some of the most serious and economically significant diseases in livestock, posing major problems for animal health authorities around the world.

Although large-scale outbreaks of diseases such as contagious bovine pleuropneumonia (CBPP) are rare in Europe, there is nevertheless a serious threat of infection from some countries, where mycoplasmas are common in sheep, goats and cattle. Currently there are limited control measures to prevent infection, or to vaccinate animals against diseases caused by mycoplasmas.

Since the 1970s, scientists from around the world have collaborated in researching mycoplasmology. Many of these scientists are based in the European Union and are engaged on a series of high-level research projects to further our understanding of mycoplasmology and how to prevent, track and vaccinate against infection.

Part of that work has been carried out by genome sequencing teams, since mycoplasmas have relatively simple genomes and have proved to be obvious targets for early sequencing efforts by scientists.

There has also been work carried out in Europe looking at the classification of different species. For example, some that are carried on red blood cells were not classified as mycoplasmas until recently. There are at least 125 main species of mycoplasmas, according to Roger Ayling at the UK’s Veterinary Laboratories Agency in Weybridge, Surrey. “Each mycoplasma is generally host-specific,” he points out, meaning that each type of animal (or plant or insect) has its own kind of mycoplasma.

While some ground-breaking work in the field has taken place in the US, notably cloning an entire genome of a mycoplasma species onto another one, to identify the minimum gene requirements for life, recent work in Europe has been equally high profile. Swedish researchers have sequenced the genome of the causative agent of CBPP in order to provide tools for other researchers to produce antigens and potential vaccines.

Other projects have detected contagious caprine pleuropneumonia (CCPP) in gazelles, whereas it had been thought only to affect goats. This disease has been detected in the European part of Turkey, meaning that the continent has a current mycoplasma threat.

At the Veterinary Laboratories Agency, the Mycoplasma Group have worked on a project identifying biofilm in mycoplasmas – a sugar matrix that is excreted by the organism, helping it to survive longer and possibly making it harder for antibiotics to tackle. They have also developed a new microbial detection and identification method.

“Whereas in the old days of detecting we used to use culture methods which could take up to 28 days, this helps us to detect and identify mycoplasma species within as little as 24 hours. This is quite an advance,” Ayling says.

The VLA is funded by the UK government Defra, along with some commercial sponsors. The European Union has contributed funding to programmes in the past, such as the current Phytoplasma EU COST programme led by an Italian researcher, but there has been limited funding available over the past decade, according to Ayling. Small but significant groups of researchers working on mycoplasmology projects are active in the UK, Austria, Switzerland, France, Italy, Sweden and Germany.

Funding of Mycoplasma research is often on potential disease threats to a country such as CBPP and CCPP in Europe which could result in mass culls, just as outbreaks of foot and mouth and blue tongue diseases resulted in the slaughter of many thousands of animals across Europe in recent years.

There were outbreaks of mycoplasma-related diseases such as CBPP in Europe in each decade of the 20th century, most recently in 1999. So even though there has not so far been a European outbreak in the 21st century, farmers, scientists and government agencies have to be alert to the possible threat and maintain funding for innovative research, to counter potential threats. While the threat of a fresh outbreak is not currently severe, the economic consequences of diseases like CBPP are a serious concern.

There is now better public understanding of the increased resistance of bacteria to antibiotics, yet public understanding of mycoplasmology is relatively low. Research scientists such as Roger Ayling are keen to raise this awareness so that funding levels can be maintained, increasing the chance to deliver an effective vaccine against mycoplasma infections and to improve other prevention and detection mechanisms.

Elsewhere in the UK, there is work in progress on haemoplasmas in cats at Bristol University, mycoplasmas in dogs at the Royal Veterinary College, while researchers at Liverpool University and Kingston University are pursuing further projects. Besides issues related to the health of cattle, goats and sheep, researchers in mycoplasmology are concerned with avian mycoplasmas, cell culture mycoplasmas, molecular genetics and phytoplasmas.

David Nicholson