cefditoren and tosufloxacin

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

The frequency and the antibacterial sensitivity of Streptococcus pneumoniae strains isolated from 6 key hospitals (in 5 areas) and 1 otorhinolaryngology clinic in Gifu Prefecture from February to March, 1999, were investigated with several antibiotics. A total of 128 strains of Streptococcus pneumoniae were isolated throughout the study: 47 strains (36.7%) of penicillin-susceptible S. pneumoniae (PSSP), 51 strains (39.8%) of penicillin-intermediate S. pneumoniae (PISP), and 30 strains (23.4%) of penicillin-resistant S. pneumoniae (PRSP); the resistant bacteria being relatively prominent. In these hospitals, PSSP was isolated by 38.8% in all the key hospitals and by 30% in the otolaryngology clinic with almost no discernible difference. PISP was isolated by 63.3%, higher in the otolaryngology clinic and PRSP by 28.6%, higher in the key hospitals conversely. The MIC90s in PISP and PRSP were determined with the antibiotics. In result, only cefditoren (CDTR) showed favorable antibacterial activities with the MIC90 of 0.78 microgram/ml among penicillins or oral cephems. The MIC90s of carbapenems such as imipenem (IPM), meropenem (MEPM), and panipenem (PAPM) were less than 0.39 microgram/ml; particularly, PAPM showed the highest antibacterial activities. Among new quinolones such as tosufloxacin (TFLX), levofloxacin (LVFX), sparfloxacin (SPFX), and ciprofloxacin (CPFX), TFLX showed the highest antibacterial activities with the MIC90 of 0.39 microgram/ml. Other agents showed very low antibacterial activities as the MIC90s were 25 micrograms/ml in minocycline (MINO) and more than 100 micrograms/ml in clarithromycin (CAM) and clindamycin (CLDM).

Topics: Amoxicillin; Anti-Bacterial Agents; Cefaclor; Cefdinir; Cefixime; Cefmenoxime; Cefpodoxime; Ceftizoxime; Cephalosporins; Ciprofloxacin; Clarithromycin; Clindamycin; Drug Resistance, Microbial; Fluoroquinolones; Humans; Imipenem; Japan; Levofloxacin; Meropenem; Microbial Sensitivity Tests; Minocycline; Naphthyridines; Ofloxacin; Penicillin G; Penicillins; Streptococcus pneumoniae; Thienamycins

We isolated 73 streptococcus strains (41 from infections, and 32 from colonization) from various skin diseases between March, 1994, and June, 1998. In 29 out of 41 cases of infective origin, Staphylococcus aureus strains were simultaneously isolated. Twenty-four out of 28 patients with impetigo were suffering from atopic dermatitis. We confirmed that impetigo lesions where Streptococcus pyogenes was dominant in number always showed thick-walled pustules on an erythematous base; these skin lesions were considered to be an early manifestation of streptococcal impetigo. We further confirmed that thick-crusted lesions in streptococcal impetigo, where S. aureus exceeded S. pyogenes in number, were a late manifestation. Antimicrobial agents such as minocycline, fusidic acid, ofloxacin and tosufloxacin, were more effective against S. aureus strains than against beta-hemolytic streptococcal strains. In contrast, ampicillin, cefdinir, imipenem, erythromycin and vancomycin were more effective against beta-hemolytic streptococcal strains.

Topics: Ampicillin; Anti-Bacterial Agents; Anti-Infective Agents; Cephalosporins; Erythromycin; Fluoroquinolones; Fusidic Acid; Humans; Imipenem; Microbial Sensitivity Tests; Minocycline; Naphthyridines; Ofloxacin; Penicillins; Skin Diseases, Bacterial; Species Specificity; Streptococcal Infections; Streptococcus; Vancomycin