Azithromycin ; pharmacology ; therapeutic use ; Humans ; Nephrotic Syndrome ; drug therapy ; Recurrence ; Steroids ; pharmacology ; therapeutic use

BACKGROUNDIt is recognized that Haemophilus influenzae isolated from patients with otitis media forms biofilms both in vitro and in vivo, suggesting that biofilm formation in vivo might play an important role in the pathogenesis and chronicity of otitis media, but the effect of antibiotics on biofilm has not been well studied. We investigated the impact of ciprofloxacin and azithromycin on bacterial biofilms formed by Haemophilus influenzae in vitro in this study.

METHODSEleven strains of Haemophilus influenzae were isolated from sputum specimens collected from patients with acute exacerbation of chronic obstructive pulmonary diseases. Formation of bacterial biofilm was examined by crystal violet assay and a scanning electron microscope. Alterations of biofilms were measured under varying concentrations of azithromycin and ciprofloxacin.

RESULTSStriking differences were observed among strains with regard to the ability to form biofilm. Typical membrane-like structure formed by bacterial cells and extracellular matrix was detected. Initial biofilm synthesis was inhibited by azithromycin and ciprofloxacin at concentrations higher than two-fold minimal inhibitory concentration. Disruption of mature biofilms could be achieved at relatively higher concentration, and ciprofloxacin displayed more powerful activity.

CONCLUSIONSHaemophilus influenzae is capable of forming biofilm in vitro. Sufficient dosage might control early formation of biofilms. Ciprofloxacin exerts better effects on breakdown of biofilm than azithromycin at conventional concentration in clinics.

Anti-Bacterial Agents ; pharmacology ; Azithromycin ; pharmacology ; Biofilms ; drug effects ; Ciprofloxacin ; pharmacology ; Haemophilus influenzae ; drug effects ; isolation & purification ; Humans ; Lung Diseases, Obstructive ; microbiology ; Microbial Sensitivity Tests ; Microscopy, Electron, Scanning

BACKGROUND: Antimicrobial susceptibility of Legionella spp. has rarely been studied in Korea. Therefore, we aimed to determine the susceptibility of Legionella spp. to various antibiotics. METHODS: We assessed the antimicrobial susceptibility of 66 environmental and clinical Legionella isolates collected between January 2001 and December 2008 from Korea and Japan. The minimum inhibitory concentrations (MICs) of 6 antibiotics, namely, azithromycin, ciprofloxacin, clarithromycin, clindamycin, gatifloxacin, and gemifloxacin were determined by the broth microdilution method using buffered starch yeast extract broth. RESULTS: The MIC ranges of the 6 antibiotics used against the Legionella isolates were as follows: 0.004-0.062 microgram/mL (azithromycin), 0.002-0.5 microgram/mL (ciprofloxacin), 0.004-0.5 microgram/mL (clarithromycin), 0.12-4 microgram/mL (clindamycin), 0.002-0.12 microgram/mL (gatifloxacin), and 0.008-1 microgram/mL (gemifloxacin). CONCLUSIONS: Legionella spp. isolates from Korea and Japan were most susceptible to gatifloxacin. Azithromycin, clarithromycin, ciprofloxacin, and gemifloxacin were also effective for treating legionellosis.
Anti-Bacterial Agents/*pharmacology ; Azithromycin/pharmacology ; Ciprofloxacin/pharmacology ; Clarithromycin/pharmacology ; Clindamycin/pharmacology ; Drug Resistance, Bacterial ; Fluoroquinolones/pharmacology ; Humans ; Legionella/*drug effects/isolation & purification ; Legionellosis/diagnosis/microbiology ; Microbial Sensitivity Tests ; Naphthyridines/pharmacology

The validation of a simple, sensitive and specific agar diffusion bioassay, applying cylinder-plate method, for the determination of the antibiotic azithromycin in ophthalmic solutions is described. Using a strain of Bacillus subtilis ATCC 9372 as the test organism, azithromycin at concentrations ranging from 50.0 to 200.0 microg.mL(-1) could be measured in 1.6667 mg.mL(-1) ophthalmic solutions. A prospective validation of the method showed that the method was linear (r = 0. 999 9) and precise (RSD = 0. 70) and accurate (it measured the added quantities). The results obtained by bioassay method could be statistically calculated by linear parallel model and by means of regression analysis and verified using analysis of variance (ANOVA). We conclude that the microbiological assay is satisfactory for quantification of azithromycin in ophthalmic solutions.
Anti-Bacterial Agents ; administration & dosage ; analysis ; pharmacology ; Azithromycin ; administration & dosage ; analysis ; pharmacology ; Bacillus subtilis ; drug effects ; Microbial Sensitivity Tests ; Ophthalmic Solutions ; chemistry ; Quality Control

Rosacea is a common chronic cutaneous disorder that primarily occurs on the convex surfaces of the central face and is often characterized by exacerbations and remissions. A case of a 52-yr-old woman visited our clinic in February 2008 complaining typical features of rosacea including multiple pinhead to rice-sized erythematous papules. We applied various conventional treatments including topical benzoyl peroxide and metronidazole as well as oral metronidazole, isotretinoin, and doxycycline. The lesions were not controlled but were rather aggravated by complications from these treatments. Therefore, we prescribed oral azithromycin, which has anti-inflammatory effects and reduces reactive oxygen species. Ten weeks after the administration of oral azithromycin, 500 mg per day for 2 weeks, the lesions had mostly disappeared and no specific side effects related to the azithromycin were noted. Oral azithromycin dosing 500 mg/day for 2 weeks is effective for treatment of intractable rosacea.
Administration, Oral ; Azithromycin/administration & dosage/pharmacology/*therapeutic use ; Erythema/diagnosis/drug therapy ; Female ; Humans ; Middle Aged ; Reactive Oxygen Species ; Rosacea/diagnosis/*drug therapy ; Skin Diseases/drug therapy

Objective: To investigate the molecular characteristics of ciprofloxacin-cefotaxime-azithromycin co-resistant Salmonella enterica serovar Thompson (S. Thompson) isolates from sporadic cases of foodborne diseases and aquatic foods in Hunan province. Methods: Ciprofloxacin-cefotaxime-azithromycin co-resistant S. Thompson isolates were selected from samples, and broth microdilution method was used to determine the resistance to 11 antibiotics of these isolates in vitro. Whole genome sequencing was used for investigating antimicrobial resistance gene patterns and phylogenetic relationships of strains. Results: Nine ciprofloxacin-cefotaxime-azithromycin co-resistant isolates were recovered from 19 S. Thompson isolates. Among nine ciprofloxacin-cefotaxime-azithromycin co-resistant isolates, eight of them harbored IncC plasmids, simultaneously carrying plasmid-mediated quinolone resistance (PMQR) genes qepA and qnrS1, β-lactamase resistance gene bla_CMY-2, azithromycin resistance gene mph(A), and one isolate harbored IncR plasmid, and carried PMQR genes qnrB4 and aac(6')-Ib-cr, bla_OXA-10 and mph(A). Genetic environment analysis showed that qnrS1, qepA, mph(A) and bla_CMY-2 genes might be integrated on genomes of strains by ISKra4, IS91, IS6100 and ISEcp1, respectively. Phylogenetic core genome comparisons demonstrated that ciprofloxacin-cefotaxime-azithromycin co-resistant isolates from patients and aquatic foods were genetically similar and clustered together. Conclusion: Ciprofloxacin-cefotaxime-azithromycin co-resistant S. Thompson isolates have been isolated from both human and aquatic food samples, suggesting that the spread of multidrug resistant Salmonella between human and aquatic animals.
Animals ; Humans ; Ciprofloxacin ; Cefotaxime ; Azithromycin ; Serogroup ; Phylogeny ; Drug Resistance, Multiple, Bacterial/genetics* ; Anti-Bacterial Agents/pharmacology* ; Salmonella ; Quinolones ; Foodborne Diseases ; Plasmids ; Salmonella enterica ; Microbial Sensitivity Tests

BACKGROUND/AIMS: This study was performed to compare the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates among different regions of Korea. METHODS: H. pylori were isolated from gastric mucosal biopsy specimens of 99 Koreans who lived in Gyeonggi (n=40), Kangwon province (n=40) and Busan (n=19) from April to August in 2008. All the patients had no history of H. pylori eradication therapy. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin, and moxifloxacin were tested according to the agar dilution method. RESULTS: There was a difference in resistance to clarithromycin in three institutes located among Gyeonggi (32.5%), Kangwon province (12.5%) and Busan (42.1%) by One way ANOVA test (p=0.027) and nonparametric Kruskal Wallis test (p=0.027). However, by post-hoc analysis, there was no statistically significant difference among three regions. Similarly, the other 7 antibiotics (amoxicillin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin) did not show any significant difference. CONCLUSIONS: There was no significant regional difference of the primary antibiotic resistance of H. pylori. However, the included patient number might not be enough for this conclusion demanding further evaluations.
Amoxicillin/pharmacology ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Aza Compounds/pharmacology ; Azithromycin/pharmacology ; Ciprofloxacin/pharmacology ; Clarithromycin/pharmacology ; *Drug Resistance, Bacterial ; Female ; Helicobacter Infections/*epidemiology/microbiology ; Helicobacter pylori/*drug effects/isolation & purification ; Humans ; Male ; Metronidazole/pharmacology ; Microbial Sensitivity Tests ; Middle Aged ; Ofloxacin/pharmacology ; Quinolines/pharmacology ; Republic of Korea/epidemiology ; Tetracycline/pharmacology

BACKGROUND/AIMS: This study was performed to compare the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates among different regions of Korea. METHODS: H. pylori were isolated from gastric mucosal biopsy specimens of 99 Koreans who lived in Gyeonggi (n=40), Kangwon province (n=40) and Busan (n=19) from April to August in 2008. All the patients had no history of H. pylori eradication therapy. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin, and moxifloxacin were tested according to the agar dilution method. RESULTS: There was a difference in resistance to clarithromycin in three institutes located among Gyeonggi (32.5%), Kangwon province (12.5%) and Busan (42.1%) by One way ANOVA test (p=0.027) and nonparametric Kruskal Wallis test (p=0.027). However, by post-hoc analysis, there was no statistically significant difference among three regions. Similarly, the other 7 antibiotics (amoxicillin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin) did not show any significant difference. CONCLUSIONS: There was no significant regional difference of the primary antibiotic resistance of H. pylori. However, the included patient number might not be enough for this conclusion demanding further evaluations.
Amoxicillin/pharmacology ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Aza Compounds/pharmacology ; Azithromycin/pharmacology ; Ciprofloxacin/pharmacology ; Clarithromycin/pharmacology ; *Drug Resistance, Bacterial ; Female ; Helicobacter Infections/*epidemiology/microbiology ; Helicobacter pylori/*drug effects/isolation & purification ; Humans ; Male ; Metronidazole/pharmacology ; Microbial Sensitivity Tests ; Middle Aged ; Ofloxacin/pharmacology ; Quinolines/pharmacology ; Republic of Korea/epidemiology ; Tetracycline/pharmacology

OBJECTIVECigarette smoke extract (CSE) can induce injuries of pulmonary II epithelial cells, activate nuclear factor-kappaB and increase tumor necrosis factor-alpha(TNF-alpha) secretion. This study aimed to investigate whether azithromycin can protect pulmonary II epithelial cells from injuries induced by CSE and relevant mechanisms.

METHODSPulmonary II epithelial cells (A549 cells) were cultured in vitro. After 48 hrs of culture the cells were randomly treated with serum-free DMEM only (blank control group), azithromycin + serum-free DMEM, CSE+ serum-free DMEM or CSE+azithromycin. Eight hours later the morphology of A549 cells, the activity of NF-kappaB and the levels of TNF-alpha were measured by inverted microscope, immunohistochemistry and ELISA.

RESULTSThe morphology and structure of A549 cells were changed, NF-kappaB activity increased (dark brown staining ) and TNF-alpha levels (0.307 +/- 0.036 pg/mL vs 0.234 +/- 0.028 pg/mL)increased in the CSE+ serum-free DMEM group compared with the blank control group (P < 0.01). CSE together with azithromycin treatment recovered partly the morphological injuries of A549 cells. It also attenuated NF-kappaB staining and decreased TNF-alpha levels from 0.307 +/- 0.036 pg/mL (CSE+serum-free DMEM group) to 0.269 +/- 0.009 pg/mL (P < 0.05).

CONCLUSIONSAzithromycin may inhibit NF-kappaB activity, decrease TNF-alpha secretion and thus lessen cytotoxicity of CSE to A549 cells.

Anti-Bacterial Agents ; pharmacology ; Azithromycin ; pharmacology ; Cells, Cultured ; Epithelial Cells ; drug effects ; Humans ; Immunohistochemistry ; Lung ; drug effects ; metabolism ; pathology ; NF-kappa B ; analysis ; Smoke ; adverse effects ; Tobacco ; adverse effects ; Tumor Necrosis Factor-alpha ; analysis

OBJECTIVETo evaluate the efficacy and drug resistance of azithromycin administered via continuous infusion versus intermittent administration in rats with Mycoplasma pneumonia-induced pneumonia.

METHODSPneumonia was induced in rats by intranasal administration of mycoplasma suspension. The rats with established pneumonia were randomly divided into continuous and intermittent infusion groups with intraperitoneal azithromycin injection on a daily basis for 6 consecutive days, or for 3 consecutive days followed by a 3-day rest (which was repeated twice), respectively. The bronchoalveolar lavage (BAL) and venous blood were collected before and at 3, 6, 9, and 12 days during or after the treatments for MIC test. The rats were killed for lung pathological examination, and the plasma samples were obtained for drug assays by HPLC.

RESULTSPathological examination of the lungs demonstrated better improvement in the intermittent group than in continuous group. At 12 days of the treatment, the MIC value was higher in the continuous group than in the intermittent group.

CONCLUSIONIntermittent azithromycin administration produces better therapeutic effect against Mycoplasma pneumonia than continuous drug delivery in rats with less likeliness of inducing drug resistance.

Animals ; Anti-Bacterial Agents ; administration & dosage ; pharmacology ; therapeutic use ; Azithromycin ; administration & dosage ; pharmacology ; therapeutic use ; Drug Administration Schedule ; Drug Resistance, Bacterial ; Mycoplasma pneumoniae ; drug effects ; Pneumonia, Mycoplasma ; drug therapy ; microbiology ; Rats ; Rats, Wistar