ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, May 1992, p. 1131-1132
Vol. 36, No. 5
0066-4804192/051131-02$02.00/0 Copyright C 1992, American Society for Microbiology
In Vitro Activity of Temafloxacin Compared with Those of Other Agents against 100 Clinical Isolates of Neisseria gonorrhoeae AARON E. GLATT,h12* MARINELLA CUMMINGS,3 AND WILLIAM McCORMACK3 Division of Infectious Diseases, Nassau County Medical Center, 2201 Hempstead Turnpike, East Meadow, New York 115541; Department of Medicine, SUNY Health Sciences Center at Stony Brook Stony Brook, New York 117942; and Division of Infectious Diseases, SUNY Health Sciences Center at Brooklyn, Brooklyn, New York 112033 Received 5 December 1991/Accepted 20 February 1992
The activity of temafloxacin hydrochloride was evaluated by agar dilution against 100 clinical isolates of Neisseria gonorrhoeae and compared with the activities of penicillin, tetracycline, ceftriaxone, ciprofloxacin, and ofloxacin. Temafloxacin inhibited 100% of study isolates at a concentration of 0.015 ,Ig/ml or less and was highly active against penicillin- and tetracycline-resistant strains. The in vitro activity of temafloxacin was nearly identical to that of ceftriaxone and was slightly less than that observed with ciprofloxacin and ofloxacin. Temafloxacin represents a promising alternative agent for investigation in the treatment of infection due to N. gonorrhoeae.
1:10 in tryptic soy broth to achieve an inoculum of approximately 107 CFU/ml. This inoculum was then placed onto the antibiotic medium-containing plates with a Steers replicating device. Appropriate control organisms (Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922) were also included on each plate (7). After incubation for 18 to 24 h at 35°C in the presence of 7% C02, the MIC, defined as the lowest concentration of antibiotic allowing no visible growth, was determined. Overall, of the 100 tested isolates, only 15 were susceptible to penicillin (MIC, .0.06 ,ug/ml), an additional 38 were considered moderately susceptible (MIC, 0.12 to 1 ,ug/ml), and 47 were resistant (MIC, 22 ,ug/ml). Resistance to penicillin was determined to be due to penicillinase production in 31 (31%) isolates and chromosomally mediated in 16 (16%). Tetracycline resistance (MIC, .2 ,ug/ml) was encountered with nine of the tested isolates, with high-level tetracycline resistance (MIC, >16 p,g/ml) occurring in eight of nine (88.9%) resistant strains. Two isolates exhibited both penicillinase production and tetracycline resistance, and one isolate showed both chromosomally mediated penicillin resistance and tetracycline resistance. Ceftriaxone was highly active against the N. gonorrhoeae isolates evaluated in this study, including strains showing penicillin and tetracycline resistance. One hundred percent inhibition of growth occurred at a concentration of 0.03 p,g (or less) of ceftriaxone per ml (Table 1). Temafloxacin was highly active against the N. gonorrhoeae strains included in this evaluation, with 100% inhibition occurring at a concentration of 0.015 p,g/ml or less; this antibiotic was substantially more active than penicillin and tetracycline and was comparable in activity to ceftriaxone (Table 1). In general, there did not seem to be any correlation between penicillin or tetracycline resistance and susceptibility of N. gonorrhoeae to temafloxacin. All 31 penicillinase-producing strains were inhibited by 0.0078 ,ug of temafloxacin per ml, and of the 16 isolates with chromosomally-mediated penicillin resistance, only 6 were found to require an MIC of temafloxacin of >0.0078 p,g/ml. Temafloxacin's activity against N. gonorrhoeae is compared with those of ciprofloxacin and ofloxacin in Table 1.
Increased resistance to penicillin and tetracycline among Neisseria gonorrhoeae strains has created a demand for alternative therapies (3, 8, 12). The fluoroquinolones are a useful class of agents for gonococcal infection because of their excellent in vitro activity against N. gonorrhoeae (including penicillin- and tetracycline-resistant strains), good oral bioavailability, and efficacy comparable to that of ceftriaxone in treating uncomplicated gonorrheal disease (2, 5, 11). Temafloxacin is a difluoroquinolone with a broad spectrum of activity encompassing clinically important aerobic gram-negative and gram-positive pathogens (1, 4, 6, 9, 10). Preliminary studies have shown temafloxacin to have in vitro activity against N. gonorrhoeae equivalent to those of other fluoroquinolones (1, 6, 9, 10, 13); however, knowledge of the comparative activity of temafloxacin versus standard agents is lacking. We therefore undertook a study comparing the in vitro activity of temafloxacin against N. gonorrhoeae with those of penicillin, tetracycline, ceftriaxone, and two commercially available fluoroquinolones, ciprofloxacin and ofloxacin. One hundred random clinical isolates of N. gonorrhoeae were obtained from patients attending a sexually transmitted disease clinic in Brooklyn, N.Y. Study isolates were obtained from the following sites: male urethra (48 strains), endocervix (35 strains), rectum (10 strains), and oropharynx (7 strains). Standard laboratory-grade powders were obtained from the manufacturers of each of the study drugs, and appropriate stock solutions were prepared. For temafloxacin, ciprofloxacin, ofloxacin, and ceftriaxone, the dilutions ranged from 0.001 to 4 p,g/ml, and for penicillin and tetracycline, the dilutions ranged from 0.03 to 128 p,g/ml. Testing of susceptibility to the various antibiotics in vitro was carried out by the agar dilution technique (7) with GC Agar base (Difco Laboratories, Detroit, Mich.) containing 1% IsoVitaleX (BBL Microbiology Systems, Cockeysville, Md.). The inoculum was prepared by suspending colonies of N. gonorrhoeae taken from an overnight culture in chocolate agar into tryptic soy broth to equal the turbidity of a 0.5 McFarland standard and then further diluting the colonies *
Corresponding author. 1131
1132
NOTES
ANTIMICROB. AGENTs CHEMOTHER.
TABLE 1. Comparative in vitro activity of temafloxacin and five other antibiotics against 100 clinical isolates of N. gonorrhoeae MIC (p/mlr
Antimicrobial agent
Temafloxacin Ciprofloxacin Ofloxacin
Ceftriaxone Penicillin Tetracycline 50%, MIC50; 90%,
Range
50%
90%
0.0039-0.015 0.002-0.0078 0.002-0.015 0.002-0.030 0.015-128 0.06-32
0.0078 0.0039 0.0039 0.0039 1 0.25
0.015 0.0039 0.0078 0.0078 32 1
MICg(.
The MIC for 90% of the strains tested (MIC90) of temafloxacin was roughly one dilution higher than ofloxacin and approximately two dilutions higher than ciprofloxacin. All three fluoroquinolones evaluated produced MICs substantially below established breakpoints for susceptibility. Temafloxacin has also demonstrated good in vitro activity against N. gonorrhoeae in a number of previous investigations (1, 4, 6, 9, 10). Barry and Jones (1) reported an MIC%0 of s0.03 jug/ml for temafloxacin against 58 clinical isolates of N. gonorrhoeae (including 27 penicillinase-producing strains), and Nye and colleagues (10) found an MIC90 of 0.015 ,ug/ml when 31 strains were evaluated. Segreti et al. (13) evaluated the in vitro activities of tosufloxacin, temafloxacin, and ciprofloxacin against 16 penicillinase-producing strains of N. gonorrhoeae and found MIC90s of 0.008, 0.015, and 0.004 pug/ml, respectively. The results obtained from these three investigations are in close ageement with those described herein. Hardy et al. (6) and Chin et al. (4) found higher MICgos of 0.125 and 0.25 ,ug/ml, respectively, for temafloxacin versus N. gonorrhoeae. Those reports totaled only 29 clinical isolates, however. In previous studies in which comparisons with other fluoroquinolones were performed, temafloxacin has shown activity similar to those of other agents in its class (1, 6, 9, 10, 13). Our study, which utilized the largest number of clinical isolates to date and included isolates from the urethra, endocervix, rectum, and oropharynx as well as isolates exhibiting penicillin and/or tetracycline resistance, found temafloxacin to be slightly less active in vitro than ciprofloxacin and ofloxacin. Although differences in activity between these compounds are unlikely to be of clinical importance, clinical confirmation is required. Significantly, we have demonstrated that temafloxacin has in vitro activity against N. gonorrhoeae essentially identical to that of ceftriaxone and superior to those of penicillin and tetracycline. Evaluation of this fluoroquinolone antimicrobial agent in comparative clinical trials appears warranted.
This work was supported by a grant from Abbott Laboratories.
REFERENCES 1. Barry, A. L., and R. N. Jones. 1989. In vitro activities of temafloxacin, tosufloxacin (A-61827) and five other fluoro-quinolones. J. Antimicrob. Chemother. 23:527-535. 2. Bryan, J. P., S. KL Hfr, W. Brady, N. Luo, C. Mwale, G. Mpoko, R. Krieg, E. Siwiwaliondo, C. Reichart, C. Waters, and P. L. Perine. 1990. Oral ciprofloxacin versus ceftriaxone for the treatment of urethritis from resistant Neisseria gonorrhoeae in Zambia. Antimicrob. Agents Chemother. 34:819-822. 3. Centers for Disease Control. 1987. Antibiotic-resistant strains of Neissenia gonorrhoeae. Morbid. Mortal. Weekly Rep. 36 (Suppi. 5S):lS-18S. 4. Chin, N. X., V. M. Figueredo, A. Novelli, and H. C. Neu. 1988. In vitro activity of temafloxacin, a new difluoroquinolone antimicrobial agent. Eur. J. Cin. Microbiol. Infect. Dis. 7:58463. 5. Covino, J. M., M. Cummings, B. Smith, S. Benes, K Draft, and W. M. McCormack 1990. Comparison of ofloxacin and ceftriaxone in the treatment of uncomplicated gonorrhea caused by penicillinase-producing and non-penicillinase-producing strains. Antimicrob. Agents Chemother. 34:148&149. 6. Hardy, D. J., R. N. Swanson, D. M. HBeny, N. R. Ramer, R. R. Bower, C. W. Hanson, D. T. W. Chu, and P. Fermandes. 1987. Comparative antibacterial activities of temafloxacin hydrochloride (A-62254) and two reference fluoroquinolones. Antimicrob. Agents Chemother. 31:1768-1774. 7. Jones, R. N., T. L. Gavan, C. Thorasberry, P. C. Fuchs, E. H. Gerlach, J. S. Knapp, P. Murray, and J. A. Washington U. 1989. Standardization of disk diffusion and agar dilution susceptibility tests for Neisseria gonorrhoeae: interpretive criteria and quality control guidelines for ceftriaxone, penicillin, spectinomycin, and tetracycline. J. Clin. Microbiol. 27:2758-2766. 8. Moran, J. S., and J. M. Zenllma. 1990. Therapy of gonococcal infections: options for 1989. Rev. Infect. Dis. 12(Suppl. 6): S633-S644. 9. Nakanishi, N., M. Inoue, KL Inone,, T. Yamaguchi, and S. Mitsuhashi. 1990. In vitro activity of teniafloxacin hydrochloride (TA-167 or A-62254), a new fluorinated 4-quinolone. Chemo-
therapy (Tokyo) 90t345-355. 10. Nye, KL, G. Shi, J. M. Andrews, J. P. Ashby, and R. Wise. 1989. The in-vitro activity, pharmacokinetics and tissue penetration of temafloxacin. J. Antimicrob. Chemother. 24:415-424. 11. Pabst, K M., N. A. Siqgel, S. Smith, J. .R Black, H. H. Handsfield, and E. W. Hook II. 1989. Multicenter, comparative study of enoxacin and ceftriaxone for treatment of uncomplicated gonorrhea. Sex. Transm. Dis. 16:148-151. 12. Schwarcz, S. K., J. M. Zeniman, D. Schnell, J.5. Knapp, E. W. Hook HI, S. Thompson, F. N. Judson, and KL K Holme. 1990. National surveillance of antimicrobial resistance in Neisseria gonorrhoeae. JAMA 264:1413-1417. 13. Segreti, J., D. J. Hirsch, A. A. Hrris, LK S. Kapeli, H. Orbach, and H. A. Kessler. 1990. In vitro activity of tosufloxacin (A-61827; T-3262) against selected genital pathogens. Antimicrob. Agents Chemother. 34:971-973.
Vol. 36, No. 5
0066-4804192/051131-02$02.00/0 Copyright C 1992, American Society for Microbiology
In Vitro Activity of Temafloxacin Compared with Those of Other Agents against 100 Clinical Isolates of Neisseria gonorrhoeae AARON E. GLATT,h12* MARINELLA CUMMINGS,3 AND WILLIAM McCORMACK3 Division of Infectious Diseases, Nassau County Medical Center, 2201 Hempstead Turnpike, East Meadow, New York 115541; Department of Medicine, SUNY Health Sciences Center at Stony Brook Stony Brook, New York 117942; and Division of Infectious Diseases, SUNY Health Sciences Center at Brooklyn, Brooklyn, New York 112033 Received 5 December 1991/Accepted 20 February 1992
The activity of temafloxacin hydrochloride was evaluated by agar dilution against 100 clinical isolates of Neisseria gonorrhoeae and compared with the activities of penicillin, tetracycline, ceftriaxone, ciprofloxacin, and ofloxacin. Temafloxacin inhibited 100% of study isolates at a concentration of 0.015 ,Ig/ml or less and was highly active against penicillin- and tetracycline-resistant strains. The in vitro activity of temafloxacin was nearly identical to that of ceftriaxone and was slightly less than that observed with ciprofloxacin and ofloxacin. Temafloxacin represents a promising alternative agent for investigation in the treatment of infection due to N. gonorrhoeae.
1:10 in tryptic soy broth to achieve an inoculum of approximately 107 CFU/ml. This inoculum was then placed onto the antibiotic medium-containing plates with a Steers replicating device. Appropriate control organisms (Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922) were also included on each plate (7). After incubation for 18 to 24 h at 35°C in the presence of 7% C02, the MIC, defined as the lowest concentration of antibiotic allowing no visible growth, was determined. Overall, of the 100 tested isolates, only 15 were susceptible to penicillin (MIC, .0.06 ,ug/ml), an additional 38 were considered moderately susceptible (MIC, 0.12 to 1 ,ug/ml), and 47 were resistant (MIC, 22 ,ug/ml). Resistance to penicillin was determined to be due to penicillinase production in 31 (31%) isolates and chromosomally mediated in 16 (16%). Tetracycline resistance (MIC, .2 ,ug/ml) was encountered with nine of the tested isolates, with high-level tetracycline resistance (MIC, >16 p,g/ml) occurring in eight of nine (88.9%) resistant strains. Two isolates exhibited both penicillinase production and tetracycline resistance, and one isolate showed both chromosomally mediated penicillin resistance and tetracycline resistance. Ceftriaxone was highly active against the N. gonorrhoeae isolates evaluated in this study, including strains showing penicillin and tetracycline resistance. One hundred percent inhibition of growth occurred at a concentration of 0.03 p,g (or less) of ceftriaxone per ml (Table 1). Temafloxacin was highly active against the N. gonorrhoeae strains included in this evaluation, with 100% inhibition occurring at a concentration of 0.015 p,g/ml or less; this antibiotic was substantially more active than penicillin and tetracycline and was comparable in activity to ceftriaxone (Table 1). In general, there did not seem to be any correlation between penicillin or tetracycline resistance and susceptibility of N. gonorrhoeae to temafloxacin. All 31 penicillinase-producing strains were inhibited by 0.0078 ,ug of temafloxacin per ml, and of the 16 isolates with chromosomally-mediated penicillin resistance, only 6 were found to require an MIC of temafloxacin of >0.0078 p,g/ml. Temafloxacin's activity against N. gonorrhoeae is compared with those of ciprofloxacin and ofloxacin in Table 1.
Increased resistance to penicillin and tetracycline among Neisseria gonorrhoeae strains has created a demand for alternative therapies (3, 8, 12). The fluoroquinolones are a useful class of agents for gonococcal infection because of their excellent in vitro activity against N. gonorrhoeae (including penicillin- and tetracycline-resistant strains), good oral bioavailability, and efficacy comparable to that of ceftriaxone in treating uncomplicated gonorrheal disease (2, 5, 11). Temafloxacin is a difluoroquinolone with a broad spectrum of activity encompassing clinically important aerobic gram-negative and gram-positive pathogens (1, 4, 6, 9, 10). Preliminary studies have shown temafloxacin to have in vitro activity against N. gonorrhoeae equivalent to those of other fluoroquinolones (1, 6, 9, 10, 13); however, knowledge of the comparative activity of temafloxacin versus standard agents is lacking. We therefore undertook a study comparing the in vitro activity of temafloxacin against N. gonorrhoeae with those of penicillin, tetracycline, ceftriaxone, and two commercially available fluoroquinolones, ciprofloxacin and ofloxacin. One hundred random clinical isolates of N. gonorrhoeae were obtained from patients attending a sexually transmitted disease clinic in Brooklyn, N.Y. Study isolates were obtained from the following sites: male urethra (48 strains), endocervix (35 strains), rectum (10 strains), and oropharynx (7 strains). Standard laboratory-grade powders were obtained from the manufacturers of each of the study drugs, and appropriate stock solutions were prepared. For temafloxacin, ciprofloxacin, ofloxacin, and ceftriaxone, the dilutions ranged from 0.001 to 4 p,g/ml, and for penicillin and tetracycline, the dilutions ranged from 0.03 to 128 p,g/ml. Testing of susceptibility to the various antibiotics in vitro was carried out by the agar dilution technique (7) with GC Agar base (Difco Laboratories, Detroit, Mich.) containing 1% IsoVitaleX (BBL Microbiology Systems, Cockeysville, Md.). The inoculum was prepared by suspending colonies of N. gonorrhoeae taken from an overnight culture in chocolate agar into tryptic soy broth to equal the turbidity of a 0.5 McFarland standard and then further diluting the colonies *
Corresponding author. 1131
1132
NOTES
ANTIMICROB. AGENTs CHEMOTHER.
TABLE 1. Comparative in vitro activity of temafloxacin and five other antibiotics against 100 clinical isolates of N. gonorrhoeae MIC (p/mlr
Antimicrobial agent
Temafloxacin Ciprofloxacin Ofloxacin
Ceftriaxone Penicillin Tetracycline 50%, MIC50; 90%,
Range
50%
90%
0.0039-0.015 0.002-0.0078 0.002-0.015 0.002-0.030 0.015-128 0.06-32
0.0078 0.0039 0.0039 0.0039 1 0.25
0.015 0.0039 0.0078 0.0078 32 1
MICg(.
The MIC for 90% of the strains tested (MIC90) of temafloxacin was roughly one dilution higher than ofloxacin and approximately two dilutions higher than ciprofloxacin. All three fluoroquinolones evaluated produced MICs substantially below established breakpoints for susceptibility. Temafloxacin has also demonstrated good in vitro activity against N. gonorrhoeae in a number of previous investigations (1, 4, 6, 9, 10). Barry and Jones (1) reported an MIC%0 of s0.03 jug/ml for temafloxacin against 58 clinical isolates of N. gonorrhoeae (including 27 penicillinase-producing strains), and Nye and colleagues (10) found an MIC90 of 0.015 ,ug/ml when 31 strains were evaluated. Segreti et al. (13) evaluated the in vitro activities of tosufloxacin, temafloxacin, and ciprofloxacin against 16 penicillinase-producing strains of N. gonorrhoeae and found MIC90s of 0.008, 0.015, and 0.004 pug/ml, respectively. The results obtained from these three investigations are in close ageement with those described herein. Hardy et al. (6) and Chin et al. (4) found higher MICgos of 0.125 and 0.25 ,ug/ml, respectively, for temafloxacin versus N. gonorrhoeae. Those reports totaled only 29 clinical isolates, however. In previous studies in which comparisons with other fluoroquinolones were performed, temafloxacin has shown activity similar to those of other agents in its class (1, 6, 9, 10, 13). Our study, which utilized the largest number of clinical isolates to date and included isolates from the urethra, endocervix, rectum, and oropharynx as well as isolates exhibiting penicillin and/or tetracycline resistance, found temafloxacin to be slightly less active in vitro than ciprofloxacin and ofloxacin. Although differences in activity between these compounds are unlikely to be of clinical importance, clinical confirmation is required. Significantly, we have demonstrated that temafloxacin has in vitro activity against N. gonorrhoeae essentially identical to that of ceftriaxone and superior to those of penicillin and tetracycline. Evaluation of this fluoroquinolone antimicrobial agent in comparative clinical trials appears warranted.
This work was supported by a grant from Abbott Laboratories.
REFERENCES 1. Barry, A. L., and R. N. Jones. 1989. In vitro activities of temafloxacin, tosufloxacin (A-61827) and five other fluoro-quinolones. J. Antimicrob. Chemother. 23:527-535. 2. Bryan, J. P., S. KL Hfr, W. Brady, N. Luo, C. Mwale, G. Mpoko, R. Krieg, E. Siwiwaliondo, C. Reichart, C. Waters, and P. L. Perine. 1990. Oral ciprofloxacin versus ceftriaxone for the treatment of urethritis from resistant Neisseria gonorrhoeae in Zambia. Antimicrob. Agents Chemother. 34:819-822. 3. Centers for Disease Control. 1987. Antibiotic-resistant strains of Neissenia gonorrhoeae. Morbid. Mortal. Weekly Rep. 36 (Suppi. 5S):lS-18S. 4. Chin, N. X., V. M. Figueredo, A. Novelli, and H. C. Neu. 1988. In vitro activity of temafloxacin, a new difluoroquinolone antimicrobial agent. Eur. J. Cin. Microbiol. Infect. Dis. 7:58463. 5. Covino, J. M., M. Cummings, B. Smith, S. Benes, K Draft, and W. M. McCormack 1990. Comparison of ofloxacin and ceftriaxone in the treatment of uncomplicated gonorrhea caused by penicillinase-producing and non-penicillinase-producing strains. Antimicrob. Agents Chemother. 34:148&149. 6. Hardy, D. J., R. N. Swanson, D. M. HBeny, N. R. Ramer, R. R. Bower, C. W. Hanson, D. T. W. Chu, and P. Fermandes. 1987. Comparative antibacterial activities of temafloxacin hydrochloride (A-62254) and two reference fluoroquinolones. Antimicrob. Agents Chemother. 31:1768-1774. 7. Jones, R. N., T. L. Gavan, C. Thorasberry, P. C. Fuchs, E. H. Gerlach, J. S. Knapp, P. Murray, and J. A. Washington U. 1989. Standardization of disk diffusion and agar dilution susceptibility tests for Neisseria gonorrhoeae: interpretive criteria and quality control guidelines for ceftriaxone, penicillin, spectinomycin, and tetracycline. J. Clin. Microbiol. 27:2758-2766. 8. Moran, J. S., and J. M. Zenllma. 1990. Therapy of gonococcal infections: options for 1989. Rev. Infect. Dis. 12(Suppl. 6): S633-S644. 9. Nakanishi, N., M. Inoue, KL Inone,, T. Yamaguchi, and S. Mitsuhashi. 1990. In vitro activity of teniafloxacin hydrochloride (TA-167 or A-62254), a new fluorinated 4-quinolone. Chemo-
therapy (Tokyo) 90t345-355. 10. Nye, KL, G. Shi, J. M. Andrews, J. P. Ashby, and R. Wise. 1989. The in-vitro activity, pharmacokinetics and tissue penetration of temafloxacin. J. Antimicrob. Chemother. 24:415-424. 11. Pabst, K M., N. A. Siqgel, S. Smith, J. .R Black, H. H. Handsfield, and E. W. Hook II. 1989. Multicenter, comparative study of enoxacin and ceftriaxone for treatment of uncomplicated gonorrhea. Sex. Transm. Dis. 16:148-151. 12. Schwarcz, S. K., J. M. Zeniman, D. Schnell, J.5. Knapp, E. W. Hook HI, S. Thompson, F. N. Judson, and KL K Holme. 1990. National surveillance of antimicrobial resistance in Neisseria gonorrhoeae. JAMA 264:1413-1417. 13. Segreti, J., D. J. Hirsch, A. A. Hrris, LK S. Kapeli, H. Orbach, and H. A. Kessler. 1990. In vitro activity of tosufloxacin (A-61827; T-3262) against selected genital pathogens. Antimicrob. Agents Chemother. 34:971-973.
