Cervical swabs

by Jim Hutchinson

The recognized agents of cervicitis are Neisseria gonorrhoeae (GC), Chlamydia trachomatis (CT) and Herpes simplex virus (HSV). CT and HSV require specific samples and processing.

In contrast to samples from the urethra, Gram stain is not reliable for the presumptive diagnosis of GC cervicitis because the potential presence of commensal Neisseria spp. limits the specificity. It is not performed.

Setup

Direct Examination

Not Indicated

Culture

Media Incubation
Vancomycin-Colistin-Nystatin Agar (VCN) CO2, 35°C x 72 hours

Interpretation Examine VCN plate after 24,48 and 72 hours incubation for colonies suspicious of GC. At 24 and 48 hours, if there is no visible growth observed, return plate quickly to the incubator to minimize loss of viability in the absence of CO2.
Reporting

Negative Report

No Neisseria gonorrhoeae isolated.
If VCN plate is overgrown by swarming Proteus or yeast, report ONLY as “Unable to rule out Neisseria gonorrhoeae due to bacterial/yeast overgrowth.”

Positive Report

Insert “Neisseria gonorrhoeae” isolated (do not quantitate), beta lactamase non-producing or producing strain. Insert comment “Report has been copied to Medical Officer of Health”.

Telephone all positive GC cultures to floor/ordering physician.

For all positive GC cultures, a Communicable Disease Report is sent to the Medical Officer of Health and is recorded in the significant isolates log book.

References Izenberg H.D.. 2003. Genital Cultures, in Clinical Microbiology Procedures Handbook, 2nd ed. Vol.1 ASM Press, Washington, D.C.

Cumitech 17A, 1993. Laboratory Diagnosis of Female Genital Tract Infectious, ASM Press.

Survey B-9412, Feb. 21, 1995. Microbiology Handling of Female Genital Specimens. A pattern of Practice Survey.