Millions of people worldwide are infected with gonorrhea every year. Men with infections usually have obvious symptoms, while women are often asymptomatic or experience mild symptoms. In both men and women, the infection usually clears up with antibiotic treatment. In a new study, a team performed the first complete comparison of gonococcal gene expression and regulation in both men and women infected with N. gonorrhoeae, identifying gender-specific signatures in infection and in antibiotic resistance genes. It was found that when the bacteria infect the man, it has a different gene expression profile than when they infect a woman.
To understand the disease in both sexes, the team looked at disease manifestation in a cohort of subjects who attended a clinic treating sexually transmitted infections in a country where there are high rates of gonorrhea and antibiotic resistance. Samples were collected from men who went to the clinic for gonorrhea treatment and from the female partners who came for treatment after confirming their partner's diagnosis.
The researchers used RNA sequencing to identify which host and bacterial genes are expressed during mucosal infection. The analysis revealed that 9 percent of gonococcal genes showed increased expression in males only and included genes involved in host immune cell interactions. Four percent of the genes showed increased expression exclusively in females and included phage-associated genes.
When sequencing whole-genome DNA, males and females showed similar antibiotic-resistant genotypes, but researchers saw four-fold higher expression of these antibiotic-resistant genes in males.
The researchers note that limitations include the small sample size and the potential variance in infection stages in the male subjects compared to the female. A larger-scale study with additional genetic analysis is currently underway.
