Method for studying the role of indigenous cervical flora in colonisation by Neisseria gonorrhoeae

Abstract

A method for quantitating cervical flora has been evaluated statistically and used to study the bacterial flora of the cervix in 14 women sexually exposed to men with gonococcal urethritis. A comparison was made between those women who subsequently became colonised with Neisseria gonorrhoeae and those who did not to determine whether either total microbial populations or the different species present could be related to colonisation by N. gonorrhoeae. Two control groups of healthy women, one of patients from a public clinic and the other of patients from a private practice, were studied in the same way. Normal flora isolates were tested in vitro for antagonism or synergism toward N. gonorrhoeae or both. Cervical flora was characterised in all patient groups by wide variations between individuals, both in type and numbers of organisms. No significant differences were found in total bacterial populations or in the number of species isolated from the cervix between patient groups. Populations of N. gonorrhoeae ranged from less than 10 bacteria to log104.36. Only one normal flora isolate, a strain of Streptococcus viridans isolated from a woman exposed to but not infected by N. gonorrhoeae, demonstrated inhibition of growth towards N. gonorrhoeae.