Researchers have identified a pair of proteins that may help develop a vaccine to prevent gonorrhoea, a sexually transmitted disease that affects millions of people around the globe, with nearly 78 million new cases estimated each year.

The pathogen that causes the disease, Neisseria gonorrhoeae, is considered a "superbug" because of its resistance to all classes of antibiotics available for treating infections.The findings published in the Journal of Bacteriology, raise hope of a new treatment for the condition."The function and extracellular location of cell envelope proteins make them attractive candidates for developing vaccines against bacterial diseases, including challenging drug-resistant pathogens, such as Neisseria gonorrhoeae," the study said.Gonorrhoea can infect the genitals, rectum and throat. It is highly damaging to reproductive and neonatal health if untreated or improperly treated. Also, babies born to infected mothers are at increased risk of blindness.More than half of infected women don't have symptoms, but those asymptomatic cases can still lead to severe consequences for the patient's reproductive health, including miscarriage or premature delivery, said Aleksandra Sikora from Oregon State University College of Pharmacy in the US.

Subjecting N. gonorrhoeae to the he phenotypic microarray screening method, Sikora's team focused on seven proteins from the bacteria's cell envelope, which consists of the outer membrane, the cell wall and the inner membrane.The goal was to see which if any of the seven proteins would show strong potential as a vaccine antigen -- a molecule that sends the immune system into action. Vaccines prevent disease because the antigens they contain trigger an immune response that allows antibodies to recognise and attack pathogens to prevent future infection."Proteins in the cell envelope play key roles in cell function and bacterial physiology," Sikora said. Two of the proteins, NGO1985 and NGO2121, showed extensive sensitivity to antimicrobial compounds and thus emerged as the most promising vaccine candidates, according to the study.