What Bacteria Cause a Bartholin Gland Abscess Besides STIs?

A painful swelling near the vagina can be distressing and embarrassing, but you are not alone. Most Bartholin gland abscesses involve bacteria from your nearby skin or bowel rather than a sexually transmitted infection (STI), though a lab culture cannot always identify every organism or explain exactly how it got there ^[1]. When the duct of the Bartholin gland becomes blocked, the trapped fluid creates a stagnant environment where these bacteria can multiply and cause an infection.

Cyst vs. Abscess

It is helpful to know the difference between a cyst and an abscess:

• A Bartholin duct cyst is a blocked, fluid-filled swelling. Many cysts are not infected, cause no symptoms, and may resolve on their own ^[2][3].
• A Bartholin gland abscess occurs when that fluid becomes infected. An abscess is typically painful and often requires a drainage procedure ^[2][3].

The information below applies specifically to infected abscesses.

The Usual Bacteria in Bartholin Abscesses

Research shows that most Bartholin abscesses are polymicrobial, meaning they are caused by a mix of several different bacterial species growing together at the same time ^[4].

The most common types of bacteria found in these abscesses include:

• Escherichia coli (E. coli): This is the single most frequent bacteria isolated from Bartholin gland abscesses ^[4][5]. E. coli normally lives in the bowel and can sometimes be present on the nearby perineal skin (the area between the vagina and anus) ^[4].
• Streptococci and Staphylococci: These are bacteria commonly found on the skin or in nearby genital, perineal, or gastrointestinal areas that frequently contribute to these infections ^[4].
• Anaerobes: These are bacteria that thrive in environments without oxygen, such as deep inside a blocked gland or a sealed abscess ^[1].

While sexually transmitted infections like gonorrhea or chlamydia can cause or be present alongside a Bartholin cyst or abscess, they are not the most usual explanation for the infection ^[6][1].

Understanding Bacterial Cultures and Treatment

When a doctor treats an abscess, drainage (using a small catheter or procedure to keep the duct open) is usually the primary treatment ^[7][3]. Antibiotics are not automatically required for every uncomplicated abscess after it is drained, but they may be considered if you have a spreading skin infection (cellulitis), a fever, or specific medical risk factors ^[7][3].

If your doctor sends a sample of the drained fluid to a laboratory for a bacterial culture, the results help identify which organisms grew, but they have distinct limitations:

• Cultures frequently come back negative: In studies, a significant portion of abscess cultures (sometimes over 40%) do not grow any bacteria ^[4][5]. A negative result does not rule out an abscess, and it is especially common if you have already taken antibiotics ^[5].
• Some bacteria are hard to grow: Routine cultures may miss anaerobic bacteria because they require specialized handling to survive outside the human body.
• STI testing is a separate test: A routine bacterial culture does not reliably detect gonorrhea or chlamydia. If your doctor suspects an STI, they will use a specific test called a nucleic-acid amplification test (NAAT) from a urine or genital swab ^[6].
• Bacteria presence does not equal acquisition method: If your culture grows E. coli or another common skin bacteria, it does not mean the infection was caused by poor hygiene, sexual activity, or any specific event ^[8][9]. Nearby bacteria may simply enter a blocked duct on their own, and this is not evidence of something you did wrong.

When to Seek Additional Care

Most Bartholin abscesses can be treated successfully in an outpatient clinic. However, you should seek prompt medical attention if you experience:

• Fever, chills, or feeling deeply unwell ^[7]
• Rapidly spreading redness, worsening pain, or escalating swelling ^[7]
• Difficulty urinating or sitting ^[9]

Additionally, if you are 40 or older and notice a new mass in the Bartholin area, your doctor may recommend a biopsy. This is a precaution to ensure the lump is actually a benign cyst or abscess and to rule out rare conditions like Bartholin gland cancer, which can mimic an abscess ^[10][11].