Researchers at Oregon State University have identified a pair of proteins that might be used to create a vaccine for gonorrhea.
Neisseria gonorrhoeae cells, the bacteria that causes gonorrhea, as seen via transmission electron microscopy.
Oregon State University
The research is important because Oregon and the nation are in the middle of a gonorrhea epidemic. The number of cases in Oregon tripled in four years.
There are several reasons for the increase, but the most troublesome is that gonorrhea bacteria is becoming increasingly immune to common antibiotics.
Now Aleksandra Sikora, a researcher at Oregon State University's College of Pharmacy, has found a pair of proteins that show promise for a vaccine.
Sikora’s team studied seven proteins in the bacteria’s cell envelope. They put each through more than 1,000 tests to see how it contributed to the survival of the cell. Researchers also checked to see if any of the proteins had potential as an antigen — a molecule that spurs the immune system to action.
“It’s like a football coach trying to choose the top quarterback among seven candidates by looking at their performance on many different teams during many different games,” Sikora said.
The researchers found a pair of proteins that showed extensive sensitivity to antimicrobial compounds. The hope is that this sensitivity can be used to create an effective vaccine.
“(The gonorrhea bacteria ) … is a difficult bacteria to work with, and it’s very diverse,” Sikora said. “It has great genome plasticity — there are huge variations between strains.”
The findings are an important step toward a potential new weapon in the fight against gonorrhea, which affects millions of people around the globe. Gonorrhea is still treatable with newer antibiotics, but public health officials worry it might not be in the future.
About half of all cases in Oregon are immune to ciprofloxacin — the old go-to drug for gonorrhea. Another 10 percent are resistant to zithromycin. A small percentage of cases are even showing reduced sensitivity to newer antibiotics such as cefixime and ceftriaxone.
Gonorrhea can be quite dangerous if untreated. It can lead to endometritis, pelvic inflammatory disease, ectopic pregnancy and infertility. Also, babies born to infected mothers are at an increased risk of blindness.
Men account for about 60 percent of cases. But more than half of infected women don’t have symptoms. That contributes to the spread of the disease; even when someone isn’t showing symptoms, the bacteria can cause severe health problems.
The OSU team checked the function of proteins using phenotypic microarrays — a high-throughput system featuring plates with 96 wells per plate, each well representing a different culture condition for the proteins.
Oregon State University
Officials in some Oregon counties are so concerned they’ve launched public awareness campaigns, with advertisements on social media sites. Health workers have even gone door-to-door to track down infected people.
Health experts say the only foolproof way to protect against sexually transmitted infections is abstinence. But a condom or other barrier can also keep diseases at bay.
The findings were recently published in the Journal of Bacteriology.