Trovafloxacin compared with levofloxacin, ofloxacin, ciprofloxacin, azithromycin and clarithromycin against unusual aerobic and anaerobic human and animal ...
JAC
Journal of Antimicrobial Chemotherapy (1998) 41, 391–396
Trovafloxacin compared with levofloxacin, ofloxacin, ciprofloxacin, azithromycin and clarithromycin against unusual aerobic and anaerobic human and animal bite-wound pathogens Ellie J. C. Goldsteina,b*, Diane M. Citrona, Marie Hudspetha, Sharon Hunt Gerardoa and C. Vreni Merriama a
R. M. Alden Research Laboratory, Santa Monica–UCLA Medical Center, Santa Monica, CA 90404; b UCLA School of Medicine, Los Angeles, CA 90024, USA The activity of trovafloxacin and five other oral agents against 250 aerobic and 137 anaerobic strains isolated from human and animal bite wounds was determined by an agar dilution method. Trovafloxacin was active against all aerobic and fastidious facultative isolates at 0.5 mg/L and all anaerobes at 2 mg/L (Bacteroides tectum, Porphyromonas salivosa and Prevotella heparinolytica, 0.25 mg/L; Porphyromonas spp., 0.5 mg/L; Prevotella spp. and peptostreptococci, 2.0 mg/L), except Fusobacterium nucleatum and other fusobacteria (MIC90 4 mg/L). Levofloxacin was generally one to two dilutions more active than ofloxacin, while ciprofloxacin was active against aerobes (MIC 1 mg/L) but less active against anaerobic strains (MIC90 16 mg/L).
Introduction
Materials and methods
Millions of people are bitten by animals and some become infected with serious complications.1 Infected dog and cat bite wounds grow pathogenic bacteria that include a wide variety of fastidious aerobic bacteria and approximately 50–80% grow anaerobic veterinary species.2 Many laboratories are unable to isolate and/or identify this plethora of organisms, since many of these species are phenotypically similar to each other and others grow slowly and may be missed unless plates are incubated for a long time. Others may grow only if enriched media are used. In-vitro susceptibility studies of these unusual isolates are often not performed due to technical factors or cost constraints. Consequently, the clinician must often rely on published studies to guide both empirical and subsequent specific antimicrobial therapeutic choices. Trovafloxacin is a new fluoroquinolone with aerobic activity and enhanced anaerobic activity3,4 that could make it useful for treating bite-wound infections. In order to determine its activity against a large variety of these pathogenic species, the susceptibility of 387 recent clinical human and animal bite-wound isolates to trovafloxacin was compared with that to other agents.
The bacteria had previously been isolated from bite wounds and identified by standard criteria.5,6 The sources of the bites were dog (153), cat (159), human (46), squirrel (2), monkey (2) and pig (1), and other or unknown animal origin (10). Ten ATCC strains were also tested. The numbers and species of isolates tested are given in the Table. Standard laboratory powders were supplied as follows: trovafloxacin and azithromycin, Pfizer Inc., New York, NY, USA; ciprofloxacin, Bayer Inc., West Haven, CT, USA; ofloxacin and levofloxacin, R.W. Johnson Pharmaceutical Research Institute, Raritan, NJ, USA; clarithromycin, Abbott Pharmaceuticals Inc., North Chicago, IL, USA. Frozen cultures were transferred twice on TSA agar supplemented with 5% sheep blood or chocolate agar for the aerobes and brucella agar supplemented with haemin, vitamin K1 and 5% sheep blood for the anaerobes. Susceptibility testing was performed according to National Committee for Clinical Laboratory Standards (NCCLS) standards.7,8 Brucella agar supplemented with haemin, vitamin K1 and 5% laked sheep blood was the basal
*Corresponding address: 2021 Santa Monica Boulevard, Suite 640E, Santa Monica, CA 90404, USA. Tel: +1-310-3151511; Fax: +1-310-3153662.
391 © 1998 The British Society for Antimicrobial Chemotherapy
E. J. C. Goldstein et al. Table. In-vitro activity of trovafloxacin, levofloxacin, ofloxacin, ciprofloxacin, azithromycin and clarithromycin against 387 animal and human bite pathogens MIC (mg/L) Organism/agent Aerobes Pasteurella multocida subsp. multocida (n 19) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Pasteurella multocida subsp. septica (n 13) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Pasteurella canis (n 9) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Pasteurella spp. (other)a (n 14) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Actinobacillus/Haemophilus spp.b (n 11) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Capnocytophaga spp. (n 7) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Corynebacterium spp.c (n 15) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin 392
range
MIC50
MIC90
0.004–0.016 0.004–0.016 0.016–0.03 0.002–0.016 0.06–0.25 0.5–2.0
0.008 0.008 0.016 0.008 0.125 1.0
0.008 0.016 0.03 0.008 0.25 2.0
0.008–0.016 0.008–0.016 0.016–0.03 0.004–0.008 0.03–0.25 0.25–2.0
0.008 0.008 0.03 0.004 0.125 1.0
0.016 0.016 0.03 0.008 0.25 1.0
0.002–0.06 0.004–0.016 0.008–0.03 0.002–0.008 0.125 0.5–4.0
0.004 0.008 0.016 0.004 0.125 1.0
0.004–0.125 0.004–0.016 0.008–0.06 0.004–0.008 0.06–0.5 0.125–8.0
0.008 0.008 0.016 0.004 0.125 1.0
0.03 0.016 0.03 0.008 0.25 4.0
0.008–0.06 0.004–0.06 0.008–0.125 0.08–0.125 0.125–4.0 0.06–16
0.016 0.008 0.016 0.016 0.25 1.0
0.06 0.06 0.125 0.125 4.0 16
0.004–0.5 0.008–1.0 0.03–1.0 0.016–1.0 0.06–1.0 0.03–0.25
0.016 0.03 0.06 0.06 0.5 0.06
0.008–0.5 0.008–1.0 0.016–4.0 0.004–0.5 0.016–16 0.016–8.0
0.06 0.06 0.25 0.06 0.03 0.016
0.25 0.5 1.0 0.5 2.0 0.5
Trovafloxacin against bite-wound pathogens Table. Continued MIC (mg/L) Organism/agent EF-4bd (n 21) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Eikenella corrodens (n 22) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Moraxella spp. (n 12) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Neisseria weaverii (n 18) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Weeksella zoohelicum (n 10) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Staphylococcus aureus (n 18) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Staphylococcus epidermidis (n 15) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin
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range
MIC50
MIC90
0.008–0.5 0.002–0.06 0.008–0.5 0.002–0.25 0.03–0.25 0.06–2.0
0.03 0.008 0.03 0.008 0.03 0.125
0.25 0.06 0.5 0.125 0.125 2.0
0.008–0.25 0.004–0.03 0.008–0.125 0.008–0.06 0.125–4.0 0.125–4.0
0.06 0.008 0.016 0.008 1.0 2.0
0.06 0.016 0.06 0.016 4.0 4.0
0.001–0.03 0.001–0.03 0.004–0.06 0.001–0.03 0.016–0.25 0.03–1.0
0.008 0.002 0.008 0.002 0.06 0.125
0.03 0.016 0.06 0.03 0.06 0.25
0.008–0.25 0.008–0.06 0.008–0.25 0.008–0.25 0.06–0.25 0.03–0.5
0.06 0.008 0.06 0.016 0.125 0.25
0.125 0.008 0.06 0.03 0.25 0.5
0.002–0.016 0.001–0.03 0.06–0.125 0.002–0.06 0.03–0.5 0.016–0.06
0.016 0.016 0.06 0.03 0.5 0.03
0.016 0.016 0.125 0.06 0.5 0.06
0.016–0.06 0.03–0.125 0.125–0.25 0.06–0.5 0.06–0.25 0.06–0.5
0.03 0.06 0.25 0.25 0.25 0.125
0.03 0.125 0.25 0.5 0.25 0.5
0.03–0.06 0.06–0.25 0.125–1.0 0.03–0.5 0.125–>16 0.03–>32
0.03 0.125 0.25 0.06 0.25 0.25
0.06 0.125 0.25 0.125 >16 >32
E. J. C. Goldstein et al. Table. Continued MIC (mg/L) Organism/agent
range
Staphylococcus spp. (other)e (n 9) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Streptococcus spp.f (n 32) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Anaerobes Bacteroides tectum (n 22) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Fusobacterium nucleatum (n 21) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Fusobacterium spp.g (n 15) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Peptostreptococcus spp. (n 8) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Porphyromonas salivosa (n 11) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin 394
MIC50
MIC90
0.03–0.125 0.06–0.25 0.125–1.0 0.06–0.25 0.06–>16 0.03–>32
0.06 0.06 0.25 0.06 0.25 0.25
0.001–0.5 0.008–0.5 0.001–2.0 0.001–2.0 0.016–>16 0.016–>32
0.06 0.25 1.0 0.5 0.03 0.03
0.125 0.5 1.0 1.0 2.0 2.0
0.03–0.25 0.125–1.0 0.25–2.0 0.25–2.0 0.5–2.0 0.125
0.06 0.125 0.25 0.25 1.0 0.125
0.125 0.25 0.5 1.0 1.0 0.125
0.03–6.0 0.06–>16 0.03–>16 0.016–>16 0.016–4.0 0.016–>16
1.0 8.0 4.0 8.0 1.0 8.0
4.0 >16 >16 >16 4.0 >16
0.03–4.0 0.125–>16 0.06–>16 0.03–>16 0.06–4.0 0.016–>16
2.0 16 >16 16 0.25 2.0
4.0 >16 >16 >16 4.0 >16
0.03–2.0 0.125–4.0 0.5–8.0 0.25–4.0 0.016–>16 0.016–>16
0.125 0.5 1.0 1.0 0.5 0.06
0.06–0.25 0.25–0.5 0.06–1.0 0.5–1.0 0.125–1.0 0.016–0.125
0.125 0.5 0.5 1.0 0.25 0.06
0.25 0.5 1.0 1.0 0.5 0.125
Trovafloxacin against bite-wound pathogens Table. Continued MIC (mg/L) Organism/agent Porphyromonas spp.h (n 22) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Prevotella heparinolytica (n 12) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin Prevotella spp.i (n 26) trovafloxacin levofloxacin ofloxacin ciprofloxacin azithromycin clarithromycin
range
MIC50
MIC90
0.06–0.25 0.25–0.5 0.06–1.0 0.5–1.0 0.125–1.0 0.016–0.125
0.125 0.5 0.5 1.0 0.25 0.06
0.25 0.5 1.0 1.0 0.5 0.125
0.25 0.25–0.5 0.25–1.0 2.0–4.0 0.25–1.0 0.03–0.125
0.25 0.25 1.0 2.0 0.5 0.06
0.25 0.5 1.0 4.0 0.5 0.06
0.06–2.0 0.125–2.0 0.25–4 0.125–4.0 0.06–2.0 0.016–0.25
0.5 0.25 1.0 1.0 0.5 0.06
1.0 0.5 1.0 4.0 1.0 0.125
a Four Pasteurella dagmatis, one Pasteurella haemolytica, two Pasteurella multocida subsp. gallicida, one Pasteurella pneumotropica, four Pasteurella stomatis and one Pasteurella testudinis. b Four Actinobacillus actinomycetemcomitans, one Haemophilus aphrophilus, two Haemophilus parainfluenzae and four other Haemophilus spp. c One Corynebacterium xerosis, one Corynebacterium striatum, two Corynebacterium minutissi, one Corynebacterium jeikeum, one Corynebacterium G-2 and nine other Corynebacterium spp. d EF-4b, Eugonic fermenter 4b is a non-motile coccobacillus particularly associated with animal bites. e One Staphylococcus capitis, one Staphylococcus haemolyticus, two Staphylococcus hominis, one Staphylococcus hyicus and four Staphylococcus intermedius. f Seven viridans streptococci, three Streptococcus constellatus, one Streptococcus equinus, one Streptococcus group C, one group E, one Streptococcus intermedius, eight Streptococcus mitis, one Streptococcus mutans, four Streptococcus sanguis I and five S. sanguis II. g One Fusobacterium gonidiaformans, three Fusobacterium necrophorum, seven Fusobacterium russii and four other fusobacteria. h Four Porphyromonas cangingivalis, five Porphyromonas canoris, two Porphyromonas cansulci, eight Porphyromonas gingivalis, two Porphyromonas circumdentaria and one other Porphyromonas sp. i Five Prevotella brevia, three Prevotella buccae, six Prevotella intermedia, one Prevotella denticola, two Prevotella loeschii, four Prevotella melaninogenica, two Prevotella zoogleoformans and three other Prevotella spp.
medium used for anaerobic species and for Eikenella corrodens, Weeksella zoohelicum and Capnocytophaga spp. Mueller–Hinton agar was used for staphylococci, and Mueller–Hinton agar supplemented with 5% sheep blood for other organisms. Antimicrobial agents were reconstituted according to the manufacturers’ instructions. Serial two-fold dilutions of antimicrobial agents were prepared on the day of the test; trovafloxacin was added at 0.001–16 mg/L, and levofloxacin, ofloxacin and ciprofloxacin at 0.001–4 mg/L for Gram-negative aerobes and 0.004–16 mg/L for Gram-positive aerobes and anaerobes. The agar plates were inoculated with a Steers replicator (Craft Machine Inc., Chester, PA, USA). The inoculum used was 10 4 cfu/spot for aerobic bacteria and 105 cfu/spot
for E. corrodens and anaerobic bacteria. E. corrodens and streptococci were incubated in 5% CO2 for 48 h and were then examined. Control strains tested included Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Bacteroides fragilis ATCC 25285 and Eubacterium lentum ATCC 43055. In addition, E. corrodens ATCC 23834, Pasteurella multocida subsp. multocida ATCC 43137 and 12947, Pasteurella haemo lytica ATCC 33396, Pasteurella multocida subsp. gallicida ATCC 51689, P. multocida subsp. septica ATCC 51688, Pasteurella stomatis ATCC 43327, Pasteurella dagmatis ATCC 43325, Pasteurella canis ATCC 43326, Pasteurella testudinis ATCC 33688, Moraxella osloensis ATCC 19976
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E. J. C. Goldstein et al. and Moraxella lacunata ATCC 17967 were tested simultaneously with the appropriate plates and environments. The MIC was defined as the lowest concentration of an agent that yielded no growth, or a marked change in the appearance of growth as compared with the growth control plate.
Acknowledgements We would like to thank Judee H. Knight, Alice E. Goldstein and Dr David Talan for various forms of assistance. This study was funded, in part, by an educational grant from US Pharmaceuticals Group, Pfizer Inc.
References Results and discussion The activity of trovafloxacin and the other agents against the bite-wound isolates tested is compared in the Table. Previous susceptibility studies of new and older compounds9 did not differentiate many of the newly identified Pasteurella spp.5 and subspecies nor the Prevotella and Porphyromonas spp. isolated from these wounds 10 and therefore scant data are available to the clinician upon which to base selection of empirical therapy. All four fluoroquinolones tested were active against the aerobic strains tested but trovafloxacin was more active against anaerobes. Trovafloxacin was active at 0.5 mg/L for aerobes and 2.0 mg/L for anaerobes except the fusobacteria (MIC 90 4 mg/L). Wexler et al.4 reported on the activity of trovafloxacin against 557 anaerobes and Spangler et al.3 on 489 anaerobes, but these studies did not include many of the species studied in this report. Wexler et al.4 and Spangler et al.3 reported that Fusobacterium nucleatum had an MIC90 of 0.5 mg/L and 0.25 mg/L, respectively, and that other Fusobacterium spp. had an MIC90 of 0.5 mg/L and 1.0 mg/L, respectively, while in our study the MIC90s for F. nucleatum and other fusobacteria was 4 mg/L. As we used the same methods as Wexler et al.4, the reason for this disparity was unclear except that we studied veterinary isolates recovered from human infections while they used human isolates from other sources. Spangler et al.3 used supplemented Wilkins– Chalgren agar which might account for some variation. Of interest, the different Pasteurella spp. tested were all susceptible to all of the fluoroquinolones ( 0.1 mg/L), but differences were found between azithromycin (MIC90 0.25 mg/L) and clarithromycin (MIC90 4.0 mg/L) (Table). Trovafloxacin appears to have improved activity against the full spectrum of pathogens isolated from human and animal bite wounds and merits further clinical evaluation.
1. Goldstein, E. J. C. (1992). Bite wounds and infection. Clinical Infectious Diseases 14, 633–8. 2. Goldstein, E. J. C., Citron, D. M., Wield, B., Blachman, U., Sutter, V. L., Miller, T. A. et al. (1978). Bacteriology of human and animal bite wounds. Journal of Clinical Microbiology 8, 667–72. 3. Spangler, S. K., Jacobs, M. R. & Appelbaum, P. C. (1994). Activity of CP 99,219 compared with those of ciprofloxacin, grepafloxacin, metronidazole, cefoxitin, piperacillin, and piperacillin–tazobactam against 489 anaerobes. Antimicrobial Agents and Chemotherapy 38, 2471–6. 4. Wexler, H. M., Molitoris, E., Molitoris, D. & Finegold, S. M. (1996). In vitro activities of trovafloxacin against 557 strains of anaerobic bacteria. Antimicrobial Agents and Chemotherapy 40, 2232–5. 5. Holst, E., Rollof, J., Larsson, L. & Nielsen, J. P. (1992). Characterization and distribution of Pasteurella species recovered from infected humans. Journal of Clinical Microbiology 30, 2984–7. 6. Murray, P. R., Baron, E. J., Pfaller, M. A., Tenover, F. C. & Yolken, R. H. (1995). Manual of Clinical Microbiology, 6th edn. American Society for Microbiology, Washington, DC. 7. National Committee for Clinical Laboratory Standards. (1993). Methods for Antimicrobial Susceptibility Testing of Anaerobic Bacteria—Third Edition; Approved Standard M11-A3. NCCLS, Villanova, PA. 8. National Committee for Clinical Laboratory Standards. (1993). Method for Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aerobically—Third Edition: Approved Standard M7-A3. NCCLS, Villanova. PA. 9. Goldstein, E. J. C. & Citron, D. M. (1993). Comparative susceptibilities of 173 aerobic and anaerobic bite wound isolates to sparfloxacin, temafloxacin, clarithromycin, and older agents. Antimicrobial Agents and Chemotherapy 37, 1150–3. 10. Alexander, C. J., Citron, D. M., Gerardo, S. H., Claros, M. C., Talan, D. & Goldstein E. J. C. (1997). Characterization of saccharolytic Bacteroides and Prevotella isolates from infected dog and cat bite wounds in humans. Journal of Clinical Microbiology 35, 406–11. Received 22 May 1997; returned 25 June 1997; revised 11 July 1997; accepted 28 October 1997
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