[Show abstract][Hide abstract] ABSTRACT: Antibacterial agents disrupt the ecological balance of the normal human microflora. Tigecycline, a member of a new class of antibiotics (glycylcyclines), has been shown to have a potent broad-spectrum activity against most gram-positive and gram-negative aerobic and anaerobic bacteria. The aim of the study was to investigate the ecological effects of tigecycline on the normal oropharyngeal and intestinal microflora of healthy subjects. Thirteen healthy white subjects (six females and seven males) between 20 and 31 years of age received 100 mg of tigecycline in the morning on day 1 as a 30-min intravenous infusion followed by a 50-mg dose of tigecycline every 12 h as a 30-minute infusion for 10 days. One subject was withdrawn on day 2 because of an adverse event (urticaria). Serum, saliva, and fecal samples were collected before, during, and after administration for microbiological cultivation and for assays of tigecycline. All new colonizing bacteria were tested for susceptibility (resistance of > or =8 mg/liter) during the investigation period. The fecal concentrations on day 8 were from 3.0 to 14.1 mg/kg, with a mean value of 6.0 mg/kg and a median value of 5.6 mg/kg. The saliva concentrations were generally low (0 to 0.12 mg/liter). A minor effect on the oropharyngeal microflora was observed. The numbers of enterococci and Escherichia coli cells in the intestinal microflora were reduced at day 8 (P < 0.05), while those of other enterobacteria and yeasts increased. There was a marked reduction of lactobacilli and bifidobacteria (P < 0.05) but no impact on bacteroides. No Clostridium difficile strains were isolated. Two Klebsiella pneumoniae strains and five Enterobacter cloacae strains resistant to tigecycline were found on day 8.
Antimicrobial Agents and Chemotherapy 10/2006; 50(10):3375-80. · 4.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The objective was to study the prevalence and antibiotic susceptibility patterns of Propionibacterium acnes strains isolated from patients with moderate to severe acne in Stockholm, Sweden and to determine the diversity of pulsed-field gel electrophoresis types among resistant P. acnes strains. One hundred antibiotic-treated patients and 30 non-antibiotic-treated patients with moderate to severe acne participated in the investigation. Facial, neck and trunk skin samples were taken with the agar gel technique. The susceptibility of P. acnes strains to tetracycline, erythromycin, clindamycin and trimethoprim-sulfamethoxazole was determined by the agar dilution method. The genomic profiles of the resistant strains were determined by pulsed-field gel electrophoresis. In the group of patients treated with antibiotics, resistant P. acnes strains were recovered in 37%, while in the non-antibiotic group of patients the incidence of resistant strains was 13%. Thus antibiotic-resistant P. acnes strains were significantly more often isolated from antibiotic-treated patients with moderate to severe acne than from non-antibiotic-treated patients (odds ratio, 3.8; P=0.01). There was a genetic diversity among the P. acnes strains. Forty-four different patterns of SpeI DNA digests were detected and two predominant clones were found. P. acnes strains exhibited different antibiotic susceptibility patterns and identical genotypes or vice versa. A person can be colonized with different strains with varying degrees of antibiotic resistance. The risk of increased resistance of P. acnes must be considered when treating acne patients with antibiotics, and especially long-term therapy should be avoided.
[Show abstract][Hide abstract] ABSTRACT: The purpose of the study was to determine the in vitro activity of ABT-492 compared with that of other antimicrobial agents against anaerobic bacteria. The activity of ABT-492 was investigated against 369 clinical isolates of anaerobic bacteria by the agar dilution method and was compared with that of moxifloxacin, piperacillin, cefoxitin, imipenem, clindamycin and metronidazole. ABT-492 and imipenem were the most active antimicrobial agents tested.
[Show abstract][Hide abstract] ABSTRACT: The purpose of the study reported here was to determine the in vitro activity of ABT-773 compared with that of other antimicrobial agents against anaerobic bacteria. The activity of ABT-773 was investigated against 354 clinical isolates of anaerobic bacteria by the agar dilution method and was compared with that of azithromycin, clarithromycin, roxithromycin, erythromycin, cefoxitin, imipenem, clindamycin and metronidazole. ABT-773 and imipenem were the most active antimicrobial agents tested.
European Journal of Clinical Microbiology 09/2000; 19(8):635-7. · 2.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of the present investigation was to determine the in vitro activity of HMR 3647 compared with other antimicrobial agents against anaerobic bacteria. The activity of HMR 3647 was determined against 342 clinical isolates of anaerobic bacteria by the agar dilution method and was compared with azithromycin, clarithromycin, roxithromycin, erythromycin, cefoxitin, imipenem, clindamycin and metronidazole. Among the macrolides HMR 3647 and among the beta-lactams imipenem were the most active agents tested. Anaerobic cocci (50 strains) had the following minimum inhibitory concentrations (MICs): HMR 3647, range 0.016-0.125 mg/l; imipenem, range 0.016-0.064 mg/l. Propionibacterium acnes (30 strains): HMR 3647, 0.016-1.0 mg/l; imipenem, 0.032-0.064 mg/l. Clostridium perfringens (30 strains): HMR 3647, 0.125 mg/l; imipenem, 0.016-0.5 mg/l. Clostridium difficile (50 strains): HMR 3647, 0.125-256 mg/l; imipenem, 4.0-8.0 mg/l. Bacteroides fragilis (102 strains): HMR 3647, 0.032-16 mg/l; imipenem, 0.064-0.25 mg/l. Bacteroides and Prevotella species (50 strains): HMR 3647, 0.016-4.0 mg/l; imipenem, 0.016-0.25 mg/l. Fusobacterium nucleatum (30 strains): HMR 3647, 0.016-8.0 mg/l; imipenem, 0.008-0.064 mg/l. HMR 3647 may be useful as treatment and prophylaxis for infections due to anaerobic bacteria.