New selective medium for the isolation of Neisseria gonorrhoeae.
GC-Lect, a new selective medium for the isolation of Neisseria gonorrhoeae which contains five antimicrobial agents, was evaluated with stock cultures and with 500 clinical specimens. With stock cultures, vancomycin-resistant Staphylococcus epidermidis that grew on modified Thayer-Martin medium (MTM) was inhibited on the new medium. Also, vancomycin-susceptible strains of N. gonorrhoeae were much less inhibited on the new medium than on Martin-Lewis agar or MTM. With oropharyngeal cultures of healthy volunteers, Capnocytophaga species were frequently isolated on MTM from two of three manufacturers but were completely inhibited on GC-Lect. In the clinical study, visible growth of N. gonorrhoeae occurred within 24 h in 72% of the positive cultures on GC-Lect, compared with only 52% on the reference medium. A total of 50 positive cultures were obtained with GC-Lect, compared with 49 obtained with MTM. The selectivity of GC-Lect was superior, with only 19 cultures producing growth of normal flora, compared with 78 cultures on MTM after 24 h of incubation. The selectivity was especially improved on GC-Lect with regard to yeasts (2 versus 30 cultures) and gram-positive cocci (5 versus 31 cultures).
Evans
G L
GL
Becton Dickinson Microbiology Systems, Cockeysville, Maryland 21030.
Kopyta
D L
DL
Crouse
K
K
D003470:Culture Media; D006801:Humans; D009344:Neisseria gonorrhoeae / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification*; D010614:Pharynx / Q000382:microbiology; D014640:Vancomycin / Q000494:pharmacology
D003470:Culture Media; D014640:Vancomycin