New Antimicrobial Agents

Comparative Activity of the Topical Quinolone OPC-7251 against Bacteria Associated with Acne Vuigaris K. Vogtl*, j. H e r m a n n 2, U. B l u m e 3, H. Gollnick 3, H. H a h n 1, U . E Haustein 2, C.E. O r f a n o s 3

The antibacterial activity of the topical quinolone OPC-7251 against bacteria commonly found in ache vulgaris was tested in vitro by an agar dilution method. The MIC50 was 0.25 mg/i for Propionibacterlum aches, 0.125 mg/! for Propionibacterium granulosum, 0.03 mg/l for Staphylococcus aureus and 0.06 mg/l for Coagulase.negativc staphylococci. Compared with seven other antibiotics tested (ciprofloxacin, penicillin, erythromycin, tetracycline, dindamycin, fusidic acid and gentamicin), OPC-7251 had potent activity against both propionibacteria and staphylococci and the lowest incidence of resistant strains.

Non-inflamed and inflamed lesions in acne vulgaris are colonized with gram-positive microorganisms in up to 79 % of cases (1). These include propionibacteria, staphylococci, micrococci, aerobic coryneforms and Malassezia spp. (2). The microorganisms are apparently not responsible for the primary events in the pathogenesis of acne Vulgaris, namely comedogenesis, however they seem to be important in the initiation and maintenance of the inflammatory processes of ache (1). The principles of acne therapy are comedolysis and prevention of comedo formation, sebosuppression, antibacterial therapy and prevention of inflammation. Early intervention With antibacterial drugs such as antibiotics, benZoyl peroxide and azeaic acid helps to reduce inflammation and prevent scarring, the latter being an unwanted outcome of acne (3). ~ t u t e of MedicalMicrobiology,Free Universityof Berlin, Hindenburedamm 27 1000 Berlin 45 Germany. Department of Dermatology,Dlv~monof Mycologyand Microbiology,Universityof Leipzig,Liebigstral3e21, 7010 Leipzig, Germany 3i) epartment " of Dermatology,University Medical Center Steglitz, Free Universityof Berlin, Hindenburgdamm30, 10(1t)Berlin 45, Germany.

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Antibiotics are administered either systemically or topically. The most commonly used agents are erythromycin, tetracycline, minocycline and clindamycin. However, resistance may arise during therapy (4), necessitating a search for alternative substances. OPC-7251 is a fluoroquinolone which acts by inhibiting the formation of supercoiled DNA by DNA gyrase. Its chemical formula is shown in Figure 1. In vitro experiments have revealed potent antibacterial activity against aerobic and anaerobic bacteria (5). Local application of 0.25 %, 0.5 % and 1 % OPC-7251 cream showed concentration-dependent antimicrobial activity in experimental subcutaneous infections in mice caused by Propionibacterium acnes, Staphylococcus epidermidis and Staphylococcus aureus (6). A double-blind clinical study of OPC-7251 1 % cream versus cream base in acne patients showed a significant reduction of the post-treatment Propionibacterium acnes count in the former group; moreover, the clinical response to OPC7251 was significantly superior (7). The present study compares the in vitro activity of OPC-7251 with that of seven other antibiotics against four groups of bacteria which frequently colonize ache vulgaris lesions: Staphylococcus aureus, coagulase-negative staphylococci, Propionibacterium aches and Propionibacterium granulosum. Materials and Methods. Fifty strains each of Staphylococcus aureus, coagulase-negative staphylococci and Propionibacterium acnes, and five strains of Propionibacterium granulosum were tested. All strains had been isolated recently from patient specimens in our routine laboratory (wound material, blood cultures, urine) between February 1991 and August 1991. Identification was done by the coagulase reaction (StaphaurexD, Wellcome, UK) for staphylococci, and by microscopic examination and biochemical tests (APIATB system, API-bioM6rieux, France) for propionibacteria.

O

'~CH3 Figure 1: Chemicalstructure of 0PC-7251.

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Eur. J. Clin. Microbiol. Infect. Dis.

Table 1: In vitro activity of 0PC-7251 compared to seven other antibiotics against organisms associated with acne vulgaris. Organism

Antibiotic

M I C (mg/I) MIC50

Staphylococcus aureus

MIC90

Range

OPC-7251 Ciprofloxacin Penicillin Erythromycin Tetracycline Clindamycin Fusidic acid Gentamicin

0.03 0.125 2 0.25 0.25 0.06 0.015 0.5

0.06 0.25 >8 8 >8 0.125 0125 2

< 0.015 0.03 < 0.015 < 0.015 0.125 < 0.015 < 0.015 0.06

Coagulase-negative staphylococci (n = 50)

OPC-7251 Ciprofloxacin Penicillin Erythromycin Tetracycline Clindamycin Fusidic acid Gentamicin

0.06 0.25 4 0.25 2 0.06 0.015 0.5

4 >8 >8 >8 >8 >8 >8 >8

0.030.06 < 0.015 < 0.015 0.06 < 0.015 < 0.015 < 0.015 -

4 >8 >8 >8 >8 >8 >8 >8

Propionibacterium aches

OPC-7251 Ciprofloxacin Penicillin Erythromycin Tetracycline Clindamycin Fusidic acid Gentamicin

0.25 1 0.015 0.06 0.5 0.03 0.125

0.030.1258 >8 >8 4

OPC-7251 Ciprofloxacin Penicillin Erythromycin Tetracycline Clindamycin Fusidic acid

0.125 0.5 0.015 0.06 0.5 0.03 0.06

0.060.25< 0.015 0.030.50.015 0.06-

0.5 2 0.06 0.125 2 0.03 1

(n=50)

(n =50)

Propionibacterium granulosum (n=5)

OPC-7251 was supplied byOtsuka Pharmaceutical, Germany, ciprofloxacin by Bayer, Germany, penicillin by Hoechst, Germany, clindamycin by Upjohn, Germany, gentamicin by Merck, Germany, and fusidic acid by Thomae, Germany. Erythromycin and tetracycline were purchased from Sigma, Germany. For MIC determinations (5) OPC-7251 had to be dissolved in I ml of 1N N a O H prior to agar dilution, and erythromycin in 1 ml of methanol. The other substances could be dissolved directly. Twofold dilutions of all antibiotics were prepared in distilled water to give end concentrations in the range of 0.015 to 8 mg/1. Agar dilution was performed with Gifu Anaerobic Medium (Nissui, Japan). Eighteen ml of warm agar were added to 2 ml of antibiotic solution, mixed thoroughly and poured into Petri dishes. Inoculation was done with a Steers' multipoint inoculator. Plates were read after 24 h of in-

1 2 0.06 0.125 0.5 0.06 1

-2 -8 ->8 ->8 ->8 ->8 ->8 ->8

cubation. The following reference strains served as controls: Staphylococcus epidermidis ATCC 12228, Bacteroides vulgatus ATCC 29327 and Pseudomonas aeruginosa ATCC 10145.

Results and Discussion. The results are summarized in Table 1. OPC-7251 had the lowest MIC90 of all antibiotics tested for Staphylococcus aureus. All isolates were inhibited by OPC-7251 at a concentration of 2 rag/l, whereas resistant strains with MICs exceeding 8 mg/1 were found in tests with the other antibiotics. Coagulase-negative staphylococci showed even greater resistance: the MIC90 of OPC-7251 was 4 mg/l but the MIC of all other antibiotics tested exceeded 8 mg/l. OPC-7251, penicillin, erythromycin, clindamycin and fusicid acid all showed potent activity against Propionibacterium acnes. Nevertheless, strains resistant to all agents except penicillin

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and OPC-7251 were found. High activity was documented for penicillin, erythromycin, clindamycin and fusidic acid against the five strains of

3. Golinick H, Zouboulis CC, Akamatsu H, Kurokawa I, Schulte A: Pathogenesis and pathogenesis related

Propionibacterium granulosum.

4. Eady EA, Cove JH, Holland KT, Cunliffe WJ:

Antibiotic therapy in acne vulgaris requires agents which are active against gram-positive bacteria and have acceptable or no side effects on long-term treatment. B o t h topical and systemic application are possible. D e p e n d i n g on the class of compound, galenic formulation, penetration kinetics and concentration, topical antibiotics reduce the microbial population by exerting bacteriostatic and bactericidal effects within the follicular canal. Beside indirect anti-inflammatory effects r e s u l t i n g from the killing of microbes, direct drug-related anti-inflammatory effects influence neutrophil chemotaxis (8). Systemic administration bears a higher risk of adverse drug events (9). Moreover, it encourages the development of multiple resistance. Eady et al. (10) reported an increase of multiply resistant skincolonizing staphylococci under oral erythromycin therapy. Propionibacteria are slower to develop resistance, nevertheless up to 25 % of strains were resistant after six months (10). The present study illustrates that the increasing use of gyrase inhibitors in clinical practice has not yet influenced the antimicrobial susceptibility of Staphylococcus aureus. The MIC90 for coagulasenegative staphylococci, which tend to be more resistant, was 4 mg/l. Furthermore, no resistant strains of Propionibacterium acnes or Propionibacterium granulosum were found. The spectrum of antibacterial activity of the agents tested demonstrates that agents for treatment of acne must possess stability against Staphylococcal 15-1actamase and also activity against anaerobic bacteria. Thus OPC-7251 appears to be a valuable alternative for antibiotic treatment of acne vulgaris: besides local applicability, it is active against both staphylococci and propionibacteria.

References I. Leeming JP, Holland KT, Cunliffe WJ: The microbial

colonization of inflamed ache vulgaris lesions. British Journal of Dermatology 1988, 118: 203-208. 2. Cunliffe WJ: Microbiology of acne. In: Cunliffe WJ (ed): Acne. Martin Dunitz, London, 1989, p. 178-210.

treatment of acne. Journal of Dermatology 1991, 18: 489-499. Erythromycin resistant propionibacteria in antibiotic treated acne patients: association with therapeutic failure. British Journal of Dermatology 1989, 121: 5157. 5. Kawabata S, Ohguro K, Mukai F, Ohmori K, Miyamoto H, Tamaoka H: Bacteriological evaluation

of OPC-7251, a new pyridone carboxylic acid antimicrobial agent. 1: In vitro antibacterial activity. Japanese Journal of Chemotherapy 1989, 37: 11601178.

6. Kawabata S, Masada H, Wakebe H, Ohmori K, Tamaoka H: Bacteriological evaluation of OPG-7251,

a new pyridone carboxylic acid antimicrobial agent. 2: Therapeutic effect of OPC-7251 cream on experimental infection model in mice. Japanese Journal of Chemotherapy 1989, 37: 1179-1183. 7. Kurokawa I, Akamatsu H, Nishijima S, Asada Y, Kawabata S: Clinical and bacteriological evaluation

of OPC-7251 in patients with acne: a double-blind group comparison study versus cream base. Journal of the American Academy of Dermatology 1991, 25: 674-681. 8. Lee WL, Shalita AR, Suntharalingam K, Fikrig SM:

Neutrophil chemotaxis by Propionibacterium aches lipase and its inhibition. Infection and Immunity 1982, 35: 71-78. 9. Eady EA, Holland KT, Cunliffe WJ: The use of antibiotics in acne therapy: oral or topical administration? Journal of Antimicrobial Chemotherapy 1982, 10: 89-115.

10. Eady EA, Ross JI, Cove JH, Holland KT, Cunliffe WJ: The effects of oral erythromycin therapy for acne

on the development of resistance in cutaneous staphylococci and propionibacteria. In: Marks R, Plewig G (ed): Acne and related disorders. Martin Dunitz, London, 1989, p. 265-270.