The antibiotic susceptibility of Propionibacterium acnes and Staphylococcus epidermidis isolated from acne

Antibiotic resistance in acne: changes, consequences and concerns

Antibiotic resistance in acne was first observed in the 1970s and has been a major concern in dermatology since the 1980s. The resistance rates and types of antimicrobials have subsequently shown great variations in regions and countries. Illustrative of this is the resistance to topical erythromycin and clindamycin which continues to be a problem worldwide, while resistance to systemic treatment with tetracyclines has remained low during the past decade. The resistance for the newer macrolides like azithromycin and clarithromycin has been increasing. The results of antibiotic resistance may include treatment failure of acne, disturbance of skin microbiota, induction of opportunistic pathogens locally and systemically, and dissemination of resistant strains to both healthcare personnel and the general population. The ensuing complications, such as aggravated opportunistic infections caused by Propionibacterium acnes and the emergence of multiresistant superbugs, have not yet been confirmed.

A Polycation Antimicrobial Peptide Mimic without Resistance Buildup against Propionibacterium Acnes

A preliminary study is reported for a polycation antimicrobial peptide (AMP) mimic against Propionibacterium acnes, which is associated with acne vulgaris, a common skin condition. Antibiotics are commonly used against P. acnes but buildup of resistance is well-known. Worse, antibiotic regimens build up resistance for more sensitive bacteria such as Staphylococcus epidermidis. The polycation AMP mimic C12-50, 1, is chosen for the present study as it has been previously shown to have high antimicrobial effectiveness. This study reports that C12-50 is active against P. acnes (strain ATCC 6919) with a minimum inhibitory concentration (MIC) of 6.3 µg mL^-1 . To monitor resistance build-up ten passages are conducted with C12-50 against P. acnes. The MIC remains constant with no resistance buildup. Parallel studies with erythromycin confirm previously reported resistance buildup. The results point to a promising pathway to applications for polycation AMP mimics against P. acnes.

Antibiotic resistance of microbial strains isolated from Korean acne patients

Over several decades, topical and systemic antibiotics have been the mainstay of treatment for acne vulgaris. The widespread and long-term use of antibiotics in the treatment of acne has resulted in the spread of resistant bacterial strains and treatment failure. We aimed to examine the bacteriology of acne vulgaris and to evaluate its susceptibility to the antibiotics widely used for acne in Korea. We examined the species of bacteria aerobically and anaerobically isolated from 100 Korean acne patients. Among the bacteria isolated, Staphylococcus epidermidis (36 patients) was the most common, followed by Propionibacterium acnes (30 patients). Eleven strains of P. acnes (36.7%) and 25 strains of S. epidermidis (69.4%) were resistant to one or other of the antibiotics tested. A higher proportion of P. acnes isolates were resistant to clindamycin (30%) and erythromycin (26.7%), than to any other antibiotics tested (P = 0.0003). Some S. epidermidis isolates were resistant to tetracycline and doxycycline in addition to clindamycin and erythromycin. In the previous studies, few strains of P. acnes were found to be resistant to any of the antibiotics, but this study shows that antibiotic-resistant strains have been increasing in Korea acne patients.

Penile prosthesis coating and the reduction of postoperative infection

Despite the recent development of effective oral agents for the treatment of erectile dysfunction, penile prosthesis implantation remains an effective and acceptable treatment for the significant number of men who fail to respond to nonsurgical therapy. The most serious complication that can affect the use of most prosthetic devices is infection. In penile prostheses, this can be devastating and frequently results in removal of the device despite aggressive antibiotic therapy. In recent years, new strategies have been developed in an attempt to minimize this risk. This review focuses on one such method, namely the use of an antibiotic coating on the device. It reviews recent published data regarding the effectiveness of such devices at decreasing infection rates.

Clinical evaluation of roxithromycin: a double-blind, placebo-controlled and crossover trial in patients with acne vulgaris

We clinically evaluated roxithromycin (ROM) in a double blind, placebo-controlled, and crossover trial in patients with inflammatory acne. Patients with inflammatory acne who were attending our outpatient clinic for treatment and who had not received topical or systemic treatment for the previous month were enrolled in this study. Patients were randomly separated into two groups. Group I consisted of 26 patients. The patients received 2x150 mg/day ROM orally in the first period and 2x1 placebo tablets/day in the second period. Group II consisted of 20 patients. These patients received 2x1 placebo tablets/day in the first period and 2x150 mg/day ROM orally in the second period. The first period was the first four weeks, and then there was a washout period of two weeks (5th and 6th). The second period was the next four weeks (7th to 10th weeks) after the washout period. Median acne scores had clearly decreased in both groups at the end of the study. Differences of median acne scores were statistically significant in both groups between at baseline and at the end of the study (p<0.001). The results showed that ROM is a safe and effective alternative in the treatment of inflammatory acne with few side effects and good compliance.

The combination formulation of clindamycin 1% plus benzoyl peroxide 5% versus 3 different formulations of topical clindamycin alone in the reduction of Propionibacterium acnes. An in vivo comparative study

BACKGROUND

Isolates of Propionibacterium acnes resistant to one or more anti-acne antibiotics (most commonly erythromycin) are being increasingly reported, and the emergence of resistant strains can be associated with therapeutic failure of topical treatment.

OBJECTIVE

Comparison of the in vivo effectiveness of the combination of clindamycin 1% plus benzoyl peroxide 5% in a gel formulation to that of each of 3 clindamycin 1% preparations (gel, lotion, and solution) with respect to reduction in counts of P. acnes cultured from the foreheads of healthy volunteers.

METHODS

The effects of treatment with the 4 study drugs were compared in an open-label study. Cultures were collected before, after 1 week and after 2 weeks of treatment.

RESULTS

Treatment with the combination formulation resulted in a 99.8% (> 2 logs) reduction in total propionibacterial numbers after 1 week of therapy compared with 30 to 62% (< 1 log) decreases for the different formulations of topical clindamycin alone. By the end of week 2, the combination had decreased P. acnes counts by more than 99.9% (> 3 logs) relative to reductions of from 88 to 95% (< or > 1 log) for the single agent formulations.

CONCLUSIONS

Under the conditions of the present study, the combination of clindamycin 1% plus benzoyl peroxide 5% gel produced more rapid and highly significant reductions in P. acnes compared with formulations containing clindamycin alone.

Concentration of roxithromycin in the lesions of acne vulgaris

Roxithromycin, a macrolide antibiotic, is used in the treatment of acne vulgaris, although there have been no reports on its concentration in lesions when administered orally. We investigated the concentration of roxithromycin in acne vulgaris lesions in five patients who received 150 mg roxithromycin orally twice daily for 2 weeks. The mean concentration of roxithromycin in the lesions was 0.54 microgram/ml. These results suggest that roxithromycin accumulates at therapeutic levels in the pilosebaceous system.

The bacteriology of acne vulgaris and antimicrobial susceptibility of Propionibacterium acnes and Staphylococcus epidermidis isolated from acne lesions

We examined the species of bacteria aerobically and anaerobically isolated from 30 acne lesions and determined antimicrobial susceptibilities of Propionibacterium acnes (P. acnes) and Staphylococcus epidermidis (S. epidermidis) using nine antimicrobial agents. Among the bacteria isolated, S. epidermidis was most dominant. Both P. acnes and S. epidermidis were isolated from half of the acne lesions. The MIC of seven antimicrobials (ampicillin, erythromycin, roxithromycin, clindamycin, tetracycline, minocycline, nadifloxacin) against P. acnes was under 3.13 micrograms/ml. There were very few resistant strains of P. acnes, but many of S. epidermidis. More than 30% of the S. epidermidis isolates were resistant to erythromycin, roxithromycin, and clindamycin. After long-term systemic antibiotic therapy, the resistant strains of S. epidermidis increased, but P. acnes resistance was still limited. When we use antimicrobial agents for the treatment of acne, it should be noticed that not only P. acnes but also S. epidermidis in the acne lesions may acquire resistance to antimicrobials.

Susceptibility of Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis to 10 Kampo formulations

We examined the in vitro sensitivities of three bacteria: Propionibacterium acnes, and Staphylococcus epidermidis, commonly detected in acne lesions, and Staphylococcus aureus, a common cause of skin infections, to 10 Kampo formulations (Chinese herbal medicines; combinations of powdered extracts of crude drugs). Both Staphylococcus species showed similar sensitivities to all 10 formulations, with minimum inhibitory concentrations (MICs) ranging from 25 to 400 mg/ml. P. acnes, however, was particularly sensitive to one formulation, keigai-rengyo-to (MIC, 0.78-25 mg/ml), prompting speculation that it might contain components with strong antibacterial activity to P. acnes. P. acnes showed similar sensitivities to all the other formulations (MIC 6.25-200 mg/ml). The ranges of MICs and the MIC50S (concentrations that inhibit 50% of isolates) were very similar to those previously recorded in 1990 for the two Staphylococcus species.

Activity of eleven kampo formulations and eight kampo crude drugs against Propionibacterium acnes isolated from acne patients: retrospective evaluation in 1990 and 1995

We reviewed the susceptibility of Propionibacterium acnes to eleven Kampo formulations and to eight Kampo crude drugs that had been studied by examining their minimum inhibitory concentrations (MIC) in 1990 and 1995. P. acnes strains were most sensitive to Oren-gedoku-to (OGT) among these Kampo formulations. Coptidis Rhizoma (CR) and Phellodendri Cortex (PC) inhibited the growth of P. acnes significantly among the eight Kampo crude drugs examined. The patterns of distribution of MIC of Kampo formulations and Kampo crude drugs to P. acnes in this study were almost the same as in our previous report in 1990. No significant increases in MIC of Kampo formulations and Kampo crude drugs to P. acnes were observed. We speculated that Kampo crude drugs such as CR and PC, were better than minocycline or erythromycin from the point of view of a progressive increase in MIC to P. acnes. CR and PC, which were each an ingredient of OGT, might contain some components with strong antibacterial activity to P. acnes.

Anti-lipase activity of Kampo formulations, coptidis rhizoma and its alkaloids against Propionibacterium acnes

Anti-lipase activity of Kampo formulations, Coptidis Rhizoma (CR), and its alkaloids against Propionibacterium acnes were examined in vitro. The amounts of propionic and butyric acids in the medium were measured as growth and lipase activity of P. acnes, respectively. In tributyrin-PYG medium with each concentration of Kampo formulation, CR, or the alkaloids added, the production of propionic acid was suppressed remarkably more than that of butyric acid. The suppression of production of these acids by CR was higher than that of the alkaloids. Furthermore, no lipase-negative colonies were found on the medium to which Kampo formulations were added. From these observations, we concluded that not only Kampo formulations and CR, but also their alkaloids, showed suppression of growth of P. acnes, which reduced anti-lipase activity. Furthermore, it was suggested that Kampo formulations and Kampo crude drugs with anti-lipase activity to P. acnes should be synergistic when their ingredients are combined.