BACKGROUND: Cefditoren is an oral cephalosporin with excellent activity against Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis, which are the predominant bacterial causes of community-acquired respiratory tract infections. The current study attempted to determine the antibacterial activity of cefditoren against the major clinical isolates. METHODS: According to the NCCLS recommendations, antibacterial activities of cefditoren were measured against total 504 major clinical isolates. MICs were determined by the agar dilution method, a series of doubling dilutions from 128 to 0.03 microgram/mL, on E. coli, K. pneumoniae, E. cloacae, C. freundii, S. marcescens, P. mirabilis, and Staphylococcus spp. In case of H. influenzae, S. pneumoniae, and M. catarrhalis, broth microdilution method, a series of doubling dilutions from 16 to 0.015 microgram/mL, was performed. RESULTS: Cefditoren had variable activity against Enterobacteriaceae. MIC cumulative curves showed that cefditoren had low MIC distributions against E. coli and P. mirabilis, and MIC90 were 8 and 0.5 microgram/mL, respectively. Against K. pneumoniae, E. cloacae, C. freundii, and S. marcescens, cefditoren's MIC90 values ranged from 32 to >128 microgram/mL. For clinical isolates of methicillin-susceptible S. aureus and methicillin-susceptible S. epidermidis, cefditoren had MIC90 values of 1 microgram/mL and 0.5 microgram/mL, respectively. Cefditoren had MIC90 values of 1 microgram/mL for penicillin-susceptible and penicillin-not-susceptible strains of S. pneumoniae. Cefditoren had MIC90 values of 0.03 microgram/mL and 0.5microgram/mL against H. influenzae and M. catarrhalis, respectively. CONCLUSION: Cefditoren had excellent activity against S. pneumoniae, H. influenzae, and M. catarrhalis. Cefditoren had variable activity against Enterobacteriaceae. The results of this study confirm the excellent activity of cefditoren against the major respiratory tract pathogens and suggest that cefditoren could be a good antibiotic for empiric oral treatment of community-acquired respiratory tract infections.
Agar ; Cloaca ; Enterobacteriaceae ; Haemophilus influenzae ; Influenza, Human ; Mirabilis ; Moraxella (Branhamella) catarrhalis ; Pneumonia ; Respiratory System ; Respiratory Tract Infections ; Staphylococcus ; Streptococcus pneumoniae

BACKGROUND: Cefditoren is an oral cephalosporin with excellent activity against Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis, which are the predominant bacterial causes of community-acquired respiratory tract infections. The current study attempted to determine the antibacterial activity of cefditoren against the major clinical isolates. METHODS: According to the NCCLS recommendations, antibacterial activities of cefditoren were measured against total 504 major clinical isolates. MICs were determined by the agar dilution method, a series of doubling dilutions from 128 to 0.03 microgram/mL, on E. coli, K. pneumoniae, E. cloacae, C. freundii, S. marcescens, P. mirabilis, and Staphylococcus spp. In case of H. influenzae, S. pneumoniae, and M. catarrhalis, broth microdilution method, a series of doubling dilutions from 16 to 0.015 microgram/mL, was performed. RESULTS: Cefditoren had variable activity against Enterobacteriaceae. MIC cumulative curves showed that cefditoren had low MIC distributions against E. coli and P. mirabilis, and MIC90 were 8 and 0.5 microgram/mL, respectively. Against K. pneumoniae, E. cloacae, C. freundii, and S. marcescens, cefditoren's MIC90 values ranged from 32 to >128 microgram/mL. For clinical isolates of methicillin-susceptible S. aureus and methicillin-susceptible S. epidermidis, cefditoren had MIC90 values of 1 microgram/mL and 0.5 microgram/mL, respectively. Cefditoren had MIC90 values of 1 microgram/mL for penicillin-susceptible and penicillin-not-susceptible strains of S. pneumoniae. Cefditoren had MIC90 values of 0.03 microgram/mL and 0.5microgram/mL against H. influenzae and M. catarrhalis, respectively. CONCLUSION: Cefditoren had excellent activity against S. pneumoniae, H. influenzae, and M. catarrhalis. Cefditoren had variable activity against Enterobacteriaceae. The results of this study confirm the excellent activity of cefditoren against the major respiratory tract pathogens and suggest that cefditoren could be a good antibiotic for empiric oral treatment of community-acquired respiratory tract infections.
Agar ; Cloaca ; Enterobacteriaceae ; Haemophilus influenzae ; Influenza, Human ; Mirabilis ; Moraxella (Branhamella) catarrhalis ; Pneumonia ; Respiratory System ; Respiratory Tract Infections ; Staphylococcus ; Streptococcus pneumoniae

BACKGROUND: Nasopharyngeal bacterial flora can cause respiratory tract diseases as well as invasive bacterial diseases. Moraxella catarrhalis colonizing in the nasopharynx is considered an important potential pathogen with an increasing production of beta-lactamase. This study examined the nasopharyngeal colonization rate of M. catarrhalis and the antibiotic susceptibility of M. catarrhalis. MATERIALS AND METHODS: Healthy children who visited one of the three University hospitals in the Republic of Korea or attended a day-care center around the participating hospitals were enrolled in this study. The nasopharyngeal samples were obtained by nasopharyngeal washing with normal saline and M. catarrhalis was isolated. The nasopharyngeal colonization rate of M. catarrhalis was investigated and the minimal inhibitory concentrations (MICs) were measured for commonly used oral antibiotics (amoxicillin, amoxicillin/clavulanate, cefaclor, cefixime, cefdinir, cefditoren, erythromycin and trimethoprim). RESULTS: Three hundred and seventy-nine children aged between 6 months and 5 years were enrolled, and the nasopharyngeal colonization rate of M. catarrhalis was 33% (124 children). All isolated M. catarrhalis produced beta-lactamase. The MIC90 of the antibiotics were as follows: amoxicillin, >16 mg/L; amoxicillin/clavulanate, 0.5 mg/L; cefaclor, 8 mg/L ; cefixime, 0.125 mg/L; cefdinir, 0.25 mg/L; cefditoren, 0.25 mg/L; erythromycin, 0.5 mg/L; and trimethoprim, >16 mg/L. CONCLUSIONS: M. catarrhalis was colonized in 33% of the children aged 6 months to 5 years, and showed low MICs for amoxicillin/clavulanate and oral 2nd and 3rd generation cephalosporins.
Aged ; Amoxicillin ; Anti-Bacterial Agents ; beta-Lactamases ; Cefaclor ; Cefixime ; Cephalosporins ; Child ; Colon ; Drug Resistance ; Erythromycin ; Hospitals, University ; Humans ; Moraxella ; Moraxella (Branhamella) catarrhalis ; Nasopharynx ; Republic of Korea ; Respiratory Tract Diseases ; Trimethoprim

Pneumonia is the 12th leading cause of death among Korean population in 2005. In spite of sophisticated diagnostic assessments and treatment techniques, the management of the pneumonia is still challenging. Furthermore, the emergence of antibiotic-resistant microorganisms poses difficulties to the selection of optimal antimicrobial agents. The empirical antibiotic regimen for the community-acquired pneumonia is based on the epidemiologic characteristics of the causative pathogens, for example, Streptococcus pneumoniae, Staphylococcus aureus after influenza outbreak, Klebsiella pneumoniae, Moraxella catarrhalis, and Pseudomonas aeruginosa in patients with chronic obstructive lung diseases. The most important and frequent etiologic organism is S. pneumonia according to a prospective multicenter study by investigators including the author, followed by K. pneumoniae, Chlamydia pneumoniae, P. aeruginosa, S. aureus, and M. pneumoniae in decreasing order. Still we need a nation-wide surveillance system of the community-acquired pneumonia because we are not certain about the etiology in almost half the cases of community-acquired pneumonia.
Anti-Infective Agents ; Cause of Death ; Chlamydophila pneumoniae ; Epidemiology* ; Humans ; Influenza, Human ; Klebsiella pneumoniae ; Lung Diseases, Obstructive ; Moraxella (Branhamella) catarrhalis ; Pneumonia* ; Pseudomonas aeruginosa ; Research Personnel ; Staphylococcus aureus ; Streptococcus pneumoniae

BACKGROUND: Moxifloxacin is a newly developed drug which is more potent and safe compared to previous fluoroquinolones. This drug effectively eradicates organisms such as beta-lactamase-producing or other resistant bacteria. Moxifloxacin is known to be effective in treating respiratory infections such as Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Chlamydia pneumoniae, Legionella spp. and Mycoplasma pneumoniae. METHODS: In a multicenter, randomized, open, comparative study, the efficacy and safety of oral moxifloxacin taken 400 mg once a day and clarithromycin taken 500 mg twice daily for 7 days were compared for the treatment of Korean patients with acute exacerbations of chronic bronchitis. RESULTS: A total of 170 patients were enrolled, and they were divided into two groups:87 in the moxifloxacin group and 83 in the clarithromycin group. Of those enrolled, 76 (35 for bacteriologic efficacy) in the moxifloxacin group and 77 (31 for bacteriologic efficacy) in the clarithromycin group were included in the efficacy analysis. All were included in the safety analysis. Clinical success was noted in 70 (92.1%) of 76 moxifloxacin-treated patients and 71 (92.2%) of 77 clarithromycin-treated patients. Bacteriologic success rate seemed to be higher in moxifloxacin group (73.5%) than in clarithromycin group (54.8%), but statistically insignificant (p=0.098). Drug susceptibility among organisms initially isolated was higher in moxifloxacin group on Streptococcus pneumoniae, Pseudomonas aeruginosa, Klebsiella pneumoniae(p<0.001). Adverse events were reported by 12.8% of 86 patients receiving moxifloxacin and 21.7% of 83 patients receiveing clarithromycin. Headache (4.7% vs 4.8%, moxiflosacin group vs clarithromycin group, respectively) and indigestion (2.3% vs 6.0%, moxifloxacin group vs clarithromycin group, respectively) were the most frequent side effects in the two groups. CONCLUSION: This study demonstrated that for the treatment of acute exacerbations of chronic bronchitis a 7-days course of moxifloxacin 400 mg od was clinically equivalent and microbiologically superior to clarithromycin 500 mg bid.
Bacteria ; Bronchitis, Chronic* ; Chlamydophila pneumoniae ; Clarithromycin* ; Dyspepsia ; Fluoroquinolones ; Haemophilus influenzae ; Headache ; Humans ; Klebsiella ; Legionella ; Moraxella (Branhamella) catarrhalis ; Mycoplasma pneumoniae ; Pneumonia, Mycoplasma ; Pseudomonas aeruginosa ; Respiratory Tract Infections ; Streptococcus pneumoniae

Two trials of external quality assessment for clinical microbiology laboratories were performed in 2009. A total of 16 specimens were distributed. Eight specimens were distributed to 339 laboratories with 322 (95.0%) returns in Trial I, and another eight specimens to 337 laboratories with 327 returns (97.0%) in Trial II. Two slide specimens for mycobacterium stain (AFB) were distributed in both Trial I and II. The acceptable percentages of Gram stain were relatively good for both stainability and morphology. The acceptable percentages of bacterial identification (correct answers to species level) on Sterotrophomonas maltophilia, Staphylococcus aureus, Streptococcus agalactiae, Micrococcus luteus, Vibrio parahemolyticus and Candida glabrata (Trial I) were 94.4%, 98.5%, 92.1%, 62.3%, 92.1% and 71.5%, respectively. The acceptable percentages of bacterial identification on Pseudomonas aeruginosa, Enterococcus faecalis, Candida albicans, Staphylococcus epidermidis, Moraxella catarrhalis and Enterobacter cloacae (Trial II) were 98.5%, 94.1%, 89.2%, 86.2%, 79.6% and 98.5%, respectively. The acceptable percentages for antimicrobial susceptibility tests on S. maltophilia and S. aureus (Trial I), and P. aeruginosa and E. faecalis(Trial II) were relatively good compared to data of the last year, except results using disk method for S. maltophilia. The acceptable percentages for AFB stain in Trial I and II were relatively high. In summary, the acceptable percentages of bacterial stain and identification were relatively good. However, it is still necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.
Anti-Infective Agents ; Candida albicans ; Candida glabrata ; Enterobacter cloacae ; Enterococcus faecalis ; Korea ; Micrococcus luteus ; Moraxella (Branhamella) catarrhalis ; Mycobacterium ; Pseudomonas aeruginosa ; Staphylococcus aureus ; Staphylococcus epidermidis ; Streptococcus agalactiae ; Vibrio

Two trials of external quality assessment for clinical microbiology laboratories were performed in 2007. A total of 14 specimens were distributed. Six specimens were distributed to 317 laboratories with 305 (96.2%) returns in Trial I, and 8 specimens to 320 laboratories with 309 returns (96.5%) in Trial II. For the first time, two slide specimens for mycobacterium stain (AFB) were distributed in Trial II. The acceptable percentages of Gram stain were relatively good for both stainability and morphology. The acceptable percentages of bacterial identification (correct answers to species level) on Streptococcus pyogenes, Branhamella catarrhalis, Escherichia coli, Enterococcus faecalis, Aeromonas hydrophilia and Yersinia enterocolitica (Trial I) were 83.5%, 70.8%, 98.1%, 87.0%, 89.2%, and 97.0%, respectively. The acceptable percentages of bacterial identification on Staphylococcus aureus, Pseudomonas aeruginosa, Candida tropicalis, Listeria monocytogenes, Enterococcus casseliflavus and Klebsiella pneumoniae (Trial II) were 98.1%, 97.7%, 71.6%, 77.4%, 72.4% and 96.2%, respectively. The acceptable percentages for antimicrobial susceptibility tests on E. coli and E. faecalis (Trial I), and S. aureus and P. aeruginosa (Trial II) were relatively good compared to data of recent three years. The acceptable percentages for AFB stain in Trial II were relatively high. In summary, the acceptable percentages of bacterial stain and identification were relatively good. However, it is still necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.
Aeromonas ; Candida tropicalis ; Enterococcus ; Enterococcus faecalis ; Escherichia coli ; Klebsiella pneumoniae ; Korea ; Listeria monocytogenes ; Moraxella (Branhamella) catarrhalis ; Mycobacterium ; Pseudomonas aeruginosa ; Staphylococcus aureus ; Streptococcus pyogenes ; Yersinia enterocolitica

Two trials of external quality assessment for clinical microbiology laboratories were performed in 2007. A total of 14 specimens were distributed. Six specimens were distributed to 317 laboratories with 305 (96.2%) returns in Trial I, and 8 specimens to 320 laboratories with 309 returns (96.5%) in Trial II. For the first time, two slide specimens for mycobacterium stain (AFB) were distributed in Trial II. The acceptable percentages of Gram stain were relatively good for both stainability and morphology. The acceptable percentages of bacterial identification (correct answers to species level) on Streptococcus pyogenes, Branhamella catarrhalis, Escherichia coli, Enterococcus faecalis, Aeromonas hydrophilia and Yersinia enterocolitica (Trial I) were 83.5%, 70.8%, 98.1%, 87.0%, 89.2%, and 97.0%, respectively. The acceptable percentages of bacterial identification on Staphylococcus aureus, Pseudomonas aeruginosa, Candida tropicalis, Listeria monocytogenes, Enterococcus casseliflavus and Klebsiella pneumoniae (Trial II) were 98.1%, 97.7%, 71.6%, 77.4%, 72.4% and 96.2%, respectively. The acceptable percentages for antimicrobial susceptibility tests on E. coli and E. faecalis (Trial I), and S. aureus and P. aeruginosa (Trial II) were relatively good compared to data of recent three years. The acceptable percentages for AFB stain in Trial II were relatively high. In summary, the acceptable percentages of bacterial stain and identification were relatively good. However, it is still necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.
Aeromonas ; Candida tropicalis ; Enterococcus ; Enterococcus faecalis ; Escherichia coli ; Klebsiella pneumoniae ; Korea ; Listeria monocytogenes ; Moraxella (Branhamella) catarrhalis ; Mycobacterium ; Pseudomonas aeruginosa ; Staphylococcus aureus ; Streptococcus pyogenes ; Yersinia enterocolitica

OBJECTIVETo investigate the prevalence of Moraxella catarrhalis in the nasopharyngeal region of children with respiratory infection and the sensitivity of Moraxella catarrhalis isolates to common antimicrobial drugs.

METHODSNasopharyngeal swabs were collected from 1 082 children with respiratory infection, and Moraxella catarrhalis strains were isolated. The E-test method and disc diffusion test were used to determine the sensitivity of these strains to 11 common antimicrobial drugs. The test results were interpreted with reference to the standards of European Committee on Antimicrobial Susceptibility Testing (EUCAST), Clinical and Laboratory Standards Institute (CLSI), and British Society for Antimicrobial Chemotherapy (BSAC). The nitrocefin disc method was used to detect whether the isolated strains produced β-lactamase.

RESULTSAmong the 1 082 children with respiratory infection, 77 (77/1 082, 7.12%) carried Moraxella catarrhalis in the nasopharyngeal region. All the strains produced β-lactamase. With reference to all the three standards, all the strains were sensitive to amoxycillin-clavulanate and had a susceptibility rate of >95% towards ciprofloxacin and tetracycline. According to the EUCAST and CLSI standards, the susceptibility rate of the strains towards sulfamethoxazole-trimethoprim was as high as 98.7%, and more than 80% of all strains were sensitive to the three cephalosporins detected; however, with reference to the BSAC standard, only 2.6% of the strains were sensitive to cefuroxime, with an intermediate rate of 44.2% and a drug resistance rate of 53.2%. The rate of resistance to ampicillin was 81.8%. According to the CLSI standard, the non-susceptibility rate of the strains to erythromycin was 79.2%, and according to the EUCAST or BSAC standards, their non-susceptibility rate reached 90.9%; more than one third of the strains (27/77, 35.1%) had a minimal inhibitory concentration of >256 mg/L.

CONCLUSIONSAll of the Moraxella catarrhalis isolates in the nasopharyngeal region of children with respiratory infection produce β-lactamase and are sensitive to amoxycillin-clavulanate. These isolates have high susceptibility rates to the third- and fourth-generation cephalosporins and sulfamethoxazole-trimethoprim, but most of the isolates are resistant to ampicillin, cefuroxime, and erythromycin.

Adolescent ; Child ; Child, Preschool ; Drug Resistance, Bacterial ; Female ; Humans ; Infant ; Male ; Microbial Sensitivity Tests ; Moraxella (Branhamella) catarrhalis ; drug effects ; isolation & purification ; Nasopharynx ; microbiology ; Respiratory Tract Infections ; microbiology

Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Drug Resistance, Bacterial ; Female ; Humans ; Infant ; Male ; Moraxella (Branhamella) catarrhalis ; drug effects ; Prevalence ; Respiratory Tract Infections ; epidemiology ; microbiology