cefditoren and Haemophilus-Infections

Cefditoren is a third-generation oral cephalosporin with good activity against respiratory tract pathogens, including penicillin-intermediate and -resistant strains of S. pneumoniae, and beta-lactamase producing strains of H. influenzae and M. catarrhalis. Its bacterial activity, measured by minimum inhibitory concentration (MIC), is similar or superior to that of many other commonly used antibiotics (penicillins, cephalosporins and fluoroquinolones). Considering the target attainment of T > MIC of >or= 40% a more reliable predictor of clinical and microbiologic outcomes, cefditoren covers strains of S. pneumoniae with MIC values

Topics: Adolescent; Adult; Anti-Bacterial Agents; Cephalosporins; Community-Acquired Infections; Drug Resistance, Bacterial; Haemophilus Infections; Haemophilus influenzae; Humans; Pneumococcal Infections; Respiratory Tract Infections; Streptococcus pneumoniae

Topics: Acute Disease; Adolescent; Adult; Aged; Cephalosporins; Child; Child, Preschool; Community-Acquired Infections; Drug Resistance, Bacterial; Female; Haemophilus Infections; Haemophilus influenzae; Humans; Infant; Male; Middle Aged; Otitis Media; Penicillin Resistance; Pneumococcal Infections; Streptococcus pneumoniae; Treatment Outcome

Topics: Amoxicillin; Cephalosporins; Child; Child, Preschool; Community-Acquired Infections; Haemophilus Infections; Haemophilus influenzae; Humans; Infant; Penicillin Resistance; Pharyngitis; Pharynx; Pneumococcal Infections; Streptococcus pneumoniae; Treatment Outcome

Topics: Acute Disease; Ampicillin Resistance; beta-Lactamases; Cephalosporins; Child; Child, Preschool; Community-Acquired Infections; Haemophilus Infections; Haemophilus influenzae; Humans; Infant; Otitis Media; Penicillin Resistance; Pneumococcal Infections; Prospective Studies; Respiratory Tract Infections; Streptococcus pneumoniae; Treatment Outcome

Topics: Anti-Bacterial Agents; Cephalosporins; Child, Preschool; Community-Acquired Infections; Drug Resistance, Bacterial; Female; Haemophilus Infections; Haemophilus influenzae; Humans; Male; Patient Compliance; Pneumococcal Infections; Streptococcus pneumoniae; Treatment Outcome

Topics: Adolescent; Adult; Cephalosporins; Child; Child, Preschool; Community-Acquired Infections; Female; Haemophilus Infections; Haemophilus influenzae; Humans; Infant; Male; Middle Aged; Otorhinolaryngologic Diseases; Pneumococcal Infections; Streptococcus pneumoniae; Treatment Outcome

Topics: Acute Disease; Ampicillin; Anti-Bacterial Agents; beta-Lactam Resistance; Carbapenems; Cephalosporins; Child, Preschool; Drug Resistance, Multiple, Bacterial; Fluoroquinolones; Haemophilus Infections; Haemophilus influenzae; Humans; Infant; Japan; Microbial Sensitivity Tests; Multilocus Sequence Typing; Naphthyridines; Otitis Media; Pneumococcal Vaccines; Quinolones; Streptococcus pneumoniae; Vaccines, Conjugate

Morphological changes in penicillin-resistant Streptococcus pneumoniae (PRSP) and beta-lactamase-nonproducing, ampicillin-resistant Haemophilus influenzae (BLNAR) after exposure to oral antibacterial agents could be observed over time under a phase-contrast microscope. Morphological changes in BLNAR were also observed using a scanning electron microscope. The organisms used in this study were ME19F strain identified as genotypic(g) gPRSP (serotype: 19F) and JPH002 strain identified as gBLNAR (serotype: b). The antibacterial agents used were amoxicillin (AMPC), cefditoren (CDTR), tebipenem (TBPM), and tosufloxacin (TFLX). The concentration of each antibacterial agent to which the bacteria were exposed was set at the blood level one hour after Cmax when administered to children at the usual dose. Bacteriolysis of gPRSP cells started after exposure of only 20minutes to TBPM, and 90% of the cells were lysed within 2 hours. A high bactericidal action of TBPM on gPRSP was supported by these findings. When gBLNAR was exposed to AMPC and TBPM, lysis from spheroplasts and cells with vacuoles were sometimes observed. In contrast, after gBLNAR was exposed to CDTR, lysis occurred after marked filamentation in the cells, but after exposure to TFLX, cells deduced to be killed after mild filamentation without lysis. Time-dependent morphological changes that reflect the differences in bactericidal activity and PBP affinity among beta-lactams provide beneficial information to select antibacterial agents.

Topics: Amoxicillin; Ampicillin Resistance; Anti-Bacterial Agents; Bacteriolysis; beta-Lactamases; Carbapenems; Cephalosporins; Child; Dose-Response Relationship, Drug; Fluoroquinolones; Haemophilus Infections; Haemophilus influenzae; Humans; Microscopy, Phase-Contrast; Naphthyridines; Penicillin Resistance; Pneumococcal Infections; Streptococcus pneumoniae; Time Factors

In vitro cefditoren antimicrobial activity was tested against 288 Streptococcus pneumoniae and 220 Haemophilus influenzae clinical strains isolated in our hospital from January 2005 to May 2006 by agar dilution and broth microdilution method, respectively. MICs were also determined for 13 and 10 comparison drugs, respectively. The pneumococci tested comprised 113 (39.2%) penicillin susceptible, 91 (31.6%) penicillin intermediate, and 84 (29.2%) penicillin resistant. Cefditoren was the most active drug on the basis of the MICs (MIC(90)=0.5 microg/mL), followed by ceftriaxone and levofloxacin (MIC(90)=1 microg/mL). Cefditoren MICs ranged from 0.25 to 1 microg/mL for ceftriaxone-resistant isolates, with a modal MIC of 0.5 microg/mL and an MIC(90) of 1.0 microg/mL. No S. pneumoniae isolates evaluated in this study showed MICs to cefditoren higher than 1 microg/mL (MIC range, 4 microg/mL). Against H. influenzae (Hi beta+), the rank order of intrinsic activity (MIC(90), microg/mL) was cefditoren (0.03) < cefixime (0.06)8.0).

Topics: Adolescent; Adult; Aged; Anti-Bacterial Agents; Cephalosporins; Haemophilus Infections; Haemophilus influenzae; Humans; Microbial Sensitivity Tests; Middle Aged; Penicillin Resistance; Pneumococcal Infections; Pneumonia, Pneumococcal; Respiratory Tract Infections; Spain; Streptococcus pneumoniae

Haemophilus influenzae (H. influenzae) is the most frequent bacterial pathogen of respiratory tract infections in children. Detection of antimicrobial susceptibility of H. influenzae is necessary for institution of appropriate antibiotic treatments.. A total of 281 strains of H. influenzae isolated from sputum samples of 281 pediatric patients with respiratory tract infections were recruited for study. Antibiotic susceptibility was determined by assessing minimum inhibitory concentrations (MIC) of antimicrobial agents. MIC were measured by utility of Agar dilution susceptibility test.. Of the total, 38 (13.5%) strains produced beta-lactamase (BLP), 56 (19.9%) strains were beta-lactamase non-producing, ampicillin resistant (BLNAR). The overall resistant proportion to ampicillin was 33.4%. The data indicated that sulbactam/ampicillin, cefotaxime, ceftriaxone and cefditoren are effective against BLP strains. In addition, a high prevalence of BLNAR H. influenzae strains was identified, with an overall isolation rate of 19.9%. Those strains mainly demonstrated intermediate level to ampicillin (ampicillin-MIC

Topics: Amoxicillin; Ampicillin; Anti-Bacterial Agents; beta-Lactamases; Cefotaxime; Ceftriaxone; Cephalosporins; Child; Child, Preschool; Dose-Response Relationship, Drug; Drug Resistance, Bacterial; Female; Haemophilus Infections; Haemophilus influenzae; Humans; Infant; Male; Microbial Sensitivity Tests; Respiratory Tract Infections

The activity of cefditoren and six other cephalosporins was tested against 250 pneumococci, including strains resistant to macrolides and quinolones. Cefditoren gave the lowest MICs, with MIC(50) and MIC(90) values of < or =0.016/0.03, 0.125/0.5 and 0.5/2.0 mg/L for penicillin-susceptible, -intermediate and -resistant pneumococci, respectively. A time-kill study of 12 pneumococcal strains with varying drug susceptibilities showed that cefditoren, at 2 x MIC, gave 99% killing of all strains after 12 h, with 99.9% killing after 24 h. Other cephalosporins gave similar kill kinetics but at higher concentrations. Against 160 Haemophilus influenzae, cefditoren had the lowest MICs (MIC(50) and MIC(90) both < or =0.016 mg/L), irrespective of beta-lactamase production. Time-kill studies of cefditoren compared with five other oral cephalosporins showed that cefditoren, at 8 x MIC, was bactericidal against 8/9 strains and gave 90% killing of all strains at the MIC after 12 h. Activity was bactericidal (99.9% killing) after 24 h with all drugs tested. Multistep studies of four penicillin-susceptible, four penicillin-intermediate and four penicillin-resistant strains showed that cefditoren, co-amoxiclav and cefprozil did not select for resistant mutants after 50 subcultures, compared with cefuroxime and azithromycin, where resistant mutants were selected in two and nine strains, respectively. Single-step mutation studies showed that cefditoren, at the MIC, had the lowest frequency of spontaneous mutants compared with other drugs.

Topics: Cephalosporins; Drug Resistance, Bacterial; Haemophilus Infections; Haemophilus influenzae; Humans; Microbial Sensitivity Tests; Mutation; Penicillin Resistance; Pneumococcal Infections; Respiratory Tract Infections; Streptococcus pneumoniae; Structure-Activity Relationship

Topics: Acute Disease; Cephalosporins; Child; Child, Preschool; Community-Acquired Infections; Haemophilus Infections; Haemophilus influenzae; Humans; Infant; Nasopharynx; Otitis Media; Penicillin Resistance; Pneumococcal Infections; Pulse Therapy, Drug; Retrospective Studies; Severity of Illness Index; Streptococcus pneumoniae; Treatment Outcome

Topics: Acute Disease; Ampicillin Resistance; beta-Lactamases; Cephalosporins; Child; Child, Preschool; Community-Acquired Infections; Drug Resistance, Bacterial; Haemophilus Infections; Haemophilus influenzae; Humans; Infant; Otitis Media; Penicillin Resistance; Pneumococcal Infections; Respiratory Tract Infections; Streptococcus pneumoniae

Topics: Ampicillin Resistance; Anti-Bacterial Agents; beta-Lactams; Cephalosporins; Child; Child, Preschool; Community-Acquired Infections; Haemophilus Infections; Haemophilus influenzae; Humans; Infant; Lactams; Otitis Media; Penicillin Resistance; Pneumococcal Infections; Respiratory Tract Infections; Retrospective Studies; Streptococcus pneumoniae; Treatment Outcome

Topics: Cephalosporins; Community-Acquired Infections; Female; Haemophilus Infections; Haemophilus influenzae; Humans; Infant; Otitis Media with Effusion; Penicillin Resistance; Pneumococcal Infections; Streptococcus pneumoniae; Treatment Failure; Treatment Outcome

Cefditoren, a third generation orally administered aminothiazolyl cephalosporin, has demonstrated bactericidal activity against many Gram positive and negative bacterial pathogens and stability against clinically important beta-lactamases. Cefditoren was compared to cefaclor, cefixime, and penicillins against 1 435 recently isolated strains of streptococci (312 Streptococcus pneumoniae, 165 viridans group streptococci, 142 beta-haemolytic streptococci), Haemophilus influenzae (521 strains), and Moraxella catarrhalis (295 strains). Streptococcus pneumoniae and viridans group streptococci had penicillin nonsusceptible rates of 37.8 and 35.8%, respectively. Cefditoren (MIC(90) in microg/ml/% susceptible) activity against all tested H. influenzae (0.03/100) and M. catarrhalis (0.06-0.5/100) was comparable to cefixime and significantly greater than cefaclor. Cefditoren (MIC(90), 0.5 microg/ml) was 4- to 128-fold more active than comparison beta-lactams against the pneumoococci and was the most potent beta-lactam (including penicillin) versus beta-haemolytic streptococci. Cefditoren pharmacokinetics demonstrate a T(1/2) of 1.5-2 h and C(max) values of 2.8 and 4.6 microg/ml, respectively with 200 or 400 mg doses of cefditoren pivoxil; plasma concentrations exceed 1 microg/ml for 4 to 6 hours (33-50% of dosing interval). Consequently, a susceptible MIC of /= 18 and >/= 15 mm (5-microg disk) for all cited fastidious species tested. Categorical agreement between MIC and disk tests was 94.6 to 100% with a correlation coefficient (r) range of 0.50 to 0.90 for streptococci. H. influenzae intermethod comparison results using the same interpretive criteria were in complete agreement, but exhibited a low r = 0.39. Cefditoren clearly possesses the most potent activity among currently studied oral cephalosporins or penicillin against commonly isolated bacterial pathogens causing bronchitis, pneumonia, sinusitis, or pharyngitis and was active against nearly all penicillin-resistant streptococci at

Topics: Cefaclor; Cefixime; Cephalosporins; Gram-Negative Bacterial Infections; Haemophilus Infections; Haemophilus influenzae; Humans; Microbial Sensitivity Tests; Moraxella catarrhalis; Penicillins; Streptococcal Infections; Streptococcus