Do urethral Escherichia coli cause abacterial cystitis?

Area of Science:

• Urology
• Microbiology
• Infectious Diseases

Background:

• Recurrent cystitis often presents with symptoms despite negative urine cultures, termed abacterial cystitis.
• The role of Escherichia coli (E. coli) in the periurethral area as a cause of these symptoms is unclear.

Purpose of the Study:

• To investigate if E. coli colonization of the vaginal introitus and urethra correlates with symptoms of abacterial cystitis in women with recurrent cystitis.
• To differentiate between intermittently bacteriuric (IB) and persistently non-bacteriuric (NB) patients.

Main Methods:

• Serial cultures of the vaginal introitus, external urethral meatus, and proximal urethra were performed in 92 patients with recurrent cystitis.
• Cultures were compared with patient symptoms at clinic visits when they were abacteriuric.
• E. coli isolation rates were analyzed in relation to symptomatic status and patient groups (IB vs. NB).

Main Results:

• E. coli was isolated from the vaginal introitus, urethral meatus, and proximal urethra in 41%, 66%, and 26% of visits, respectively.
• E. coli isolation was not significantly higher during symptomatic episodes overall.
• E. coli was isolated more frequently from the introital swabs of symptomatic IB women compared to symptomatic NB patients and from symptomatic versus asymptomatic IB patients.

Conclusions:

• Findings support the hypothesis that occult coliform infections may cause symptoms in IB patients with apparent abacterial cystitis.
• No direct evidence was found linking E. coli in the urethra or introitus to symptoms in persistently non-bacteriuric women.
• E. coli colonization of the introitus was more common in patients with recurrent cystitis (both IB and NB) than in controls.