Final answer:
Pelvic inflammatory disease (PID) can sometimes be caused by Gardnerella vaginalis, a bacterium that is part of the normal vaginal microflora.
Step-by-step explanation:
Pelvic inflammatory disease (PID) is usually caused by sexually transmitted organisms such as Neisseria gonorrhoeae and Chlamydia trachomatis. However, in some cases, it can be caused by an imbalance in the vaginal microbiota, specifically a decrease in lactobacilli and an increase in vaginal pH. This condition is called bacterial vaginosis, and the most common cause is Gardnerella vaginalis.
Pelvic inflammatory disease (PID) is sometimes caused by bacterial vaginosis, which can arise from an imbalance in the vaginal microflora. A common part of the vaginal microbiota that can cause such an imbalance, leading to vaginosis and potentially PID, is Gardnerella vaginalis. Conditions like PID often involve inflammation of the fallopian tubes, known as salpingitis, which can cause serious consequences, including infertility. Therefore, apart from sexually transmitted organisms like Neisseria gonorrhoeae and Chlamydia trachomatis, G. vaginalis is a noteworthy cause of PID that typically resides within the normal vaginal flora.