GAR-936 (9-t-butylglycylamido-minocycline) susceptibility test development for streptococci, Haemophilus influenzae and Neisseria gonorrhoeae: preliminary guidelines and interpretive criteria.
GAR-936, a new semisynthetic derivative of minocycline, has earlier shown promising activity against tetracycline-resistant pathogens, including Streptococcus pneumoniae. In this study, the activity of GAR-936 was tested against a total of 514 tetracycline-susceptible and -resistant strains of S. pneumoniae, beta-haemolytic streptococci, viridans group streptococci, Haemophilus influenzae and Neisseria gonorrhoeae. All strains of H. influenzae, were inhibited by < or =2 mg/l of GAR-936, with MIC(90)s for all streptococci and gonococci of < or =0.5 mg/l. Scattergrams of GAR-936 comparing MICs by broth microdilution testing and zone diameters using 30 microg disks, confirmed the proposed susceptibility criteria of < or 2 mg/l or > or =20 mm zone diameter. Clinical trial results should be correlated with these preliminary in vitro results to confirm and/or adjust these susceptibility interpretive criteria for GAR-936 when testing fastidious streptococci, H. influenzae and N. gonorrhoeae.
Deshpande
L M
LM
Medical Microbiology Division, Department of Pathology, University of Iowa College of Medicine, Iowa City, IA, USA.
Gales
A C
AC
Jones
R N
RN
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D006193:Haemophilus influenzae / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D008911:Minocycline / Q000031:analogs & derivatives / Q000494:pharmacology*; D009344:Neisseria gonorrhoeae / Q000187:drug effects*; D010403:Penicillin Resistance; D013291:Streptococcus / Q000187:drug effects*; D013752:Tetracycline / Q000494:pharmacology; D013753:Tetracycline Resistance; D000078304:Tigecycline
D000900:Anti-Bacterial Agents; D000078304:Tigecycline; D013752:Tetracycline; D008911:Minocycline