Evaluation of the standardized disk diffusion and agar dilution antibiotic susceptibility test methods by using strains of Neisseria gonorrhoeae from the United States and Southeast Asia

Abstract

Presently, most Neisseria gonorrhoeae testing is based on f-lactamase tests and agar dilution with common therapeutic agents. The National Committee for Clinical Laboratory Standards (NCCLS) recently described a disk diffusion test that produced results similar to the reference agar dilution method for the antibiotic susceptibility of N. gonorrhoeae. We obtained 71 gonococcal isolates from active-duty males aboard a United States Navy vessel while deployed in the Western Pacific during 1989. In addition, 47 isolates ofN. gonorrhoeae were obtained from sexually transmitted disease clinics within the branch clinic operations of the Naval Hospital, San Diego (SD), and tested. Antibiotic susceptibility tests by using the NCCLS agar dilution and disk diffusion techniques were compared. Among the Southeast Asia (SEA) isolates, 47% were 1i-lactamase producers compared with 10.5% of the SD isolates. The mean MICs (SEA/SD) in micrograms per milliliter for both groups were as follows:

Antimicrobial Susceptibilities and Plasmid Contents of Neisseria gonorrhoeae Isolates from Commercial Sex Workers in Dhaka, Bangladesh: Emergence of High-Level Resistance to Ciprofloxacin

“…Since the introduction of fluoroquinolone for the treatment of uncomplicated gonorrhea, ciprofloxacin has been used extensively in Southeast Asia. However, gonococcal strains with reduced susceptibility to the fluoroquinolones have been reported in Asia (25,6), the United Kingdom (10), North America (15), and Europe (1).…”

Detection and Drug Susceptibility Testing of Neisseria gonorrhoeae Using Isothermal Microcalorimetry

“…With respect to antimicrobial susceptibility testing, our results show that with rather low concentration susceptibility could be determined within 12 h. At this point isolation would be needed before running a calorimetry measurement. As isolation takes 24 h and testing takes another 12 h, results can be expected within 36 h. Overall this is still 12 h faster than conventional methods [49,50]. Use of a higher initial inoculum is expected to speed up the detection, and we estimate that with an inoculum of 10 6 CFU•mL −1 the time to results could be lowered to 28 h. This would be similar to drug susceptibility testing using direct qPCR [51].…”

Nonstoichiometric Hydroxyapatite‐Anionic Collagen Composite as Support for the Double Sustained Release of Gentamicin and Norfloxacin/Ciprofloxacin

“…Because the minimal inhibitory concentration for gentamicin for the majority of the gram‐negative bacteria is in the range from 0.16 to 1.0 μg×ml −1 (26) and for norfloxacin from 0.16 to 4.0 μg×ml −1 (27), the amount released of each antibiotic after 24 h and corresponding to 13.0 μg×ml −1 ×h −1 ×g −1 and 5.2 μg×ml −1 ×h −1 ×g −1 composite, respectively, are those required for the inhibition of bacterial growth, particularly considering the total overall antibiotic rate of release of 18.2 μg×ml −1 ×h −1 ×g −1 . This rate of release is also significantly higher than the minimal inhibitory concentration established for many gram positive bacteria (26).…”