Experimental and clinical studies on ceftizoxime in the field of oral surgery (author's transl)

Experimental and clinical studies on ceftizoxime (CZX), a new cephalosporin derivative, were carried out and the following results were obtained. 1. The minimal inhibitory concentrations of CZX, cefazolin (CEZ), cephalothin (CET), cefotiam (CTM) and cefmetazole (CMZ) against Gram-positive cocci (31 strains) and Gram-negative rods (169 strains) isolated from the patients with oral infections were determined. CZX, though somewhat less active against Gram-positive cocci than the other cephalosporins, was the most active of the antibiotics tested against Gram-negative rods. 2. The mean serum levels in 19 patients who received 1 g of CZX by intravenous drip infusion for 1 hour were as follows. 19.6 micrograms/ml 30 minutes after the start of intravenous drip infusion, 52.2 micrograms/ml after 1 hour, 25.0 micrograms/ml after 1.5 hours, 20.3 micrograms/ml after 2 hours, 7.9 micrograms/ml after 4 hours, 3.5 micrograms/ml after 6 hours. The mean peak tissue levels of CZX after 1 g dose by intravenous drip infusion for 1 hour were 14.3 micrograms/g (n = 5) in gingiva and 8.5 micrograms/g (n = 2) in bone marrow at the end of intravenous drip infusion. 3. CZX was administered to 17 patients with various infections in the oral surgical field at daily dose of 1 approximately 2 g for 3 approximately 6 days. The therapeutic effect was as follows: 'excellent' in 6 cases, 'good' in 9, 'fair' in 1 and 'poor' in 1. The final rate of effectiveness was 88.2%. No adverse reaction was observed except for 2 cases of slight elevation of S-GPT.     

Clinical studies on lenampicillin in the therapy of skin and soft tissue infections

Clinical evaluation of newly developed oral ampicillin prodrug lenampicillin (LAPC, KBT-1585) applied to patients with superficial purulent infection at a dosage of 750 approximately 1,500 mg daily was conducted. Additionally, as part of the basic study, transition of the compound to the human skin tissue was observed. With regard to transition to human skin tissue in 11 presurgery dermatitis cases, 250 mg or 500 mg of LAPC was administered to 2 approximately 3 hours before surgery. Comparison was made between concentrations in serum and in skin tissue. Results in the case of 250 mg application showed serum concentration to be 1.28 approximately 3.32 micrograms/ml, and in skin tissue, 0.13 approximately 0.82 micrograms/g. At 500 mg, serum concentration was found to be 2.23 approximately 10.05 micrograms/ml, with skin tissue concentration at 0.45 approximately 1.34 micrograms/g. Rate of clinical efficacy in the treatment of the 183 cases of superficial purulent infection was 79.2%. By grouping of the infections (Table 3), high efficacy rates were obtained in the second group, at 85.7%; in the third at 88.9%; and in the fourth group at 96.4%. Evaluation of usefulness from the standpoint of safety was 77.6%. Good results were obtained in the third group with 88.9%; and in the fourth group with 96.4%. LAPC's efficacy rates against individual strains of bacteria in simple infection are as follows: Staphylococcus aureus, 74.6%; Staphylococcus epidermidis, 76.3%; GPC, 100%; anaerobes, 87.5%. In polymicrobial infections the rate was 84.6%. The rate of efficacy against all strains of bacteria was 76.0%. Adverse reactions were found in 13 cases (14 incidences) out of 193. The rate of incidence was 7.3%, with allergic response accounting for 5 cases, digestive tract disorders, 7 cases, and mouth odor, 1 case. There were 5 cases (6 incidences) of abnormal deviation of laboratory findings. In all cases, abnormal deviations were mild and their relation to the drug was unclear.     

Fosfomycin susceptibility of clinical isolates from otorhinolaryngological infections

To investigate the clinical and bacteriological usefulness of orally administered fosfomycin calcium (FOM), the susceptibility of 558 strains to FOM was determined. These strains were isolated at our Center, between Feb. 1982 and Feb. 1983 from otorhinolaryngological infections. Several other drugs were also tested on the same strains for comparison. The results were as follows. The MIC80 of FOM was 6.25 micrograms/ml against each of aerobic Gram-positive cocci such as S. aureus, S. pyogenes, S. pneumoniae, anaerobic Gram-positive cocci such as Peptococcus spp., and H. influenzae. P. mirabilis, indole-positive Proteus spp., P. aeruginosa and K. pneumoniae were inhibited, respectively, at 3.13, 12.5, 12.5 and 50 micrograms/ml. Most of the MICs were between 3.13 and 12.5 micrograms/ml, and the difference between the MIC50 and the MIC90 was only 1 to 2 tubes since there were few resistant strains. With the comparative drugs, there was a reduction seen in the sensitivities of pipemidic acid (PPA), ampicillin (ABPC), and cephalexin (CEX) against, respectively, P. aeruginosa, beta-lactamase-producing H. influenzae and S. aureus. FOM showed good and constant sensitivity for the weakly PPA-sensitive P. aeruginosa, weakly ABPC-sensitive beta-lactamase-producing H. influenzae and weakly CEX-sensitive S. aureus. The MICs of FOM against the main problematic isolates from otorhinolaryngological infections were mostly between 3.13 and 12.5 micrograms/ml, including the above weakly PPA-, ABPC- and CEX-sensitive strains. Based on these values, FOM may be said to have moderate antibacterial efficacy when administered orally in the usual dose.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents: special references to bacteria isolated between July 1996 and June 1997]

The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in 20 facilities in Japan since July 1982. This paper describes the results obtained during period from July 1996 to June 1997. The number of cases investigated as objectives was 217 for one year. A total of 406 strains were isolated from 177 cases (81.6% of total cases). From primary infections 162 strains were isolated, and from postoperative infections 244 strains were isolated, respectively. From primary infections, anaerobic bacteria were predominant, while from postoperative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus spp. was the highest. In postoperative infections, the majority of them were Enterococcus faecalis, while in primary infections, many of them were Enterococcus avium. The isolation rate of Staphylococcus spp., especially from postoperative infections, followed that of Enterococcus spp. Among anaerobic Gram-positive bacteria, Peptostreptococcus spp. and Streptococcus spp. were commonly isolated from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by E. coli and Enterobacter cloacae. Among anaerobic Gram-negative bacteria, Bacteroides fragilis group was the majority of isolates from both types of infections. The isolation rate of aerobic Gram-negative bacillus has decreased with time, while those of anaerobes like B. fragilis group and of aerobic Gram-positive bacteria have gradually increased in both types of infections. We found vancomycin-resistant strains of neither Staphylacoccus aureus nor Enterococcus spp.; however, the MIC of arbekacin for one of strains of S. aureus was 100 micrograms/ml. Both the MIC90's of meropenem and imipenem/cilastatin against P. aeruginosa isolated in this term were 25 micrograms/ml, which were higher than those against the strains isolated in the previous years. Compared with the isolated strains in the year 1995, progress of resistance against carbapenem antibiotics was confirmed.     

Susceptibility of clinical isolates of gram-positive and gram-negative organisms to cefatrizine

The in vitro activity of cefatrizine was evaluated against 294 Gram-positive and 270 Gram-negative bacteria isolated from clinical specimens. Cefatrizine had excellent activity against Gram-positive cocci, inhibiting all except enterococci at minimal inhibitory concentrations below 1 mcg/ml. Moreover, cefatrizine was an effective antibacterial agent for most major Gram-negative species. Cefatrizine activity was tested against 34 strains of H. influenzae and 37 strains of K. pneumoniae and compared with that of other orally administered cephalosporins. Cefatrizine MIC50 values were much lower than those recorded for cephalexin and cefadroxil.     

Midecamycin acetate-susceptibility of clinical isolates from dental and oral surgical infections

To investigate the clinical and bacteriological usefulness of orally administered midecamycin acetate (MOM), the susceptibility of clinical isolates to MOM, Mb-12 (the main metabolite of MOM), josamycin (JM), ampicillin (ABPC) and cephalexin (CEX) was determined. The results are summarized as follows. Antibacterial activities of MOM against aerobic Gram-positive cocci, B. catarrhalis, and anaerobic bacteria were inferior to those of JM by 2-fold, but superior to those of CEX. Activities of MOM against S. aureus, Bacteroides spp., Fusobacterium spp., Veillonella spp. were superior to those of ABPC and CEX. Since serum and tissue concentrations of Mb-12 after 200 mg administration in humans have been reported to be 1-2 micrograms/ml, it can be presumed that the causative bacteria would be eradicated by a usual dosage of MOM used in the present study. From these considerations, it is speculated that MOM may be successfully used in the treatment of dental and oral surgical infections.     

Overall clinical evaluation of panipenem/betamipron against infections in pediatric field]

To conduct a basic-clinical study on newly developed panipenem/betamipron (CS-533/CS-443, PAPM/BP) against various infections in pediatrics, a study group was organized and a joint research by 17 institutions and their related hospitals was undertaken. The obtained results are as follows. 1. Blood concentrations and urinary excretion Pharmacokinetics of PAPM/BP in children was studied using 30 minutes intravenous drip infusion of 10 mg/10 mg/kg, 20 mg/20 mg/kg and 30 mg/30 mg/kg, respectively. Maximum blood levels of PAPM/BP were observed at the completion of drip infusion and were 26.72 +/- 8.78 micrograms/ml/18.33 +/- 8.54 micrograms/ml (mean +/- S.D.) with administration of 10 mg/10 mg, 64.80 +/- 18.50 micrograms/ml/38.74 +/- 16.41 micrograms/ml with administration of 20 mg/20 mg and 91.70 +/- 29.42 micrograms/ml/50.08 +/- 22.41 micrograms/ml with administration of 30 mg/30 mg. Dose dependency was noted with these doses. The half-life was about 1 hour for PAPM and about 0.5 hour for BP. As for urinary excretion, PAPM was excreted about 30% and BP about 70% in the first 6 hours after the start of drip infusion. 2. Clinical results Twenty-five cases of exclusion and drop-out were deducted from a total of 391 cases and 8 cases having 2 diseases concurrently were added to the remaining 366 cases, hence 374 cases were evaluated in the study as the subjects of analysis of clinical effects. As for clinical effects in cases where pathogenic bacteria were detected, 215 out of 221 cases were rated as effective or above, hence the efficacy rate of 97.3% was obtained. In cases where pathogenic bacteria were not detected, 145 out of 153 cases were rated as effective or above, thus the efficacy rate was 94.8% which is similar to that in the cases where pathogenic bacteria were detected. The daily dose levels most commonly employed were 30 to 60 mg/kg (as PAPM) administered in 3 divided doses a day, and this regimen method accounted for 52.7% of the total cases, and the efficacy rate with this regimen was 97.0%. As for the bacteriological effect 87 (96.7%) out of 90 strains of Gram-positive bacteria (GPB) disappeared and 136 (91.3%) out of 149 strains of Gram-negative bacteria (GNB) disappeared upon the treatment. The overall bacterial eradication rate for the pathogenic bacteria was 93.4%.(ABSTRACT TRUNCATED AT 400 WORDS)     

The comparative activity of twelve 4-quinolone antimicrobials against gram-positive and gram-negative anaerobes

The minimal inhibitory concentrations (MICs) of twelve 4-quinolone antimicrobials were determined for the Bacteroides fragilis group (50), Bacteroides melaninogenicus (20), Bacteroides bivius (10), Fusobacterium spp. (10), anaerobic Gram-positive cocci (50) and Clostridium spp. (20). MICs were determined using an agar dilution technique in Mueller-Hinton agar supplemented with 10% lysed horse blood. The inoculum used was approximately 10(4) colony-forming units, contained in 10 microliter of Mueller-Hinton broth, which was applied to the agar plates using a multipoint inoculator. Following inoculation, plates were incubated at 37 degrees C for 48 h in an anaerobic atmosphere. The MIC of each antimicrobial for each isolate examined was determined as the lowest concentration of the antimicrobial which completely inhibited growth of the inoculum. The minimum concentrations required to inhibit the growth of 50% (MIC50) and 90% (MIC90) of the organism examined were also determined. All of the more recently synthesised 4-quinolones showed increased activity against the anaerobic bacteria used in this study. Ciprofloxacin and ofloxacin were the most active compounds examined (Bacteroides fragilis group MIC90 ciprofloxacin 4 micrograms/ml; ofloxacin 4 microgram/ml; Bacteroides melaninogenicus MIC90 ciprofloxacin 2 micrograms/ml, ofloxacin 2 micrograms/ml; Bacteroides bivius MIC90 ciprofloxacin 16 micrograms/ml, ofloxacin 32 micrograms/ml; Fusobacterium spp. MIC90 ciprofloxacin 2 micrograms/ml, ofloxacin 4 micrograms/ml; Clostridium spp. MIC90 ciprofloxacin 1 microgram/ml, ofloxacin 1 microgram/ml and anaerobic Gram-positive cocci MIC90 ciprofloxacin 4 micrograms/ml, ofloxacin 4 micrograms/ml).     

In vitro studies with Bay V 3522, a new oral cephalosporin

The in vitro activities of Bay v 3522, cefaclor, cephalexin, cefuroxime, cefixime, amoxicillin/clavulanate (2:1) and reference penicillins were compared against 314 clinical isolates of Gram-positive and Gram-negative bacteria and nine strains of Escherichia coli that differed in their outer membrane proteins in agar dilution tests with an inoculum of 10(4) cfu/spot. The beta-lactamase stabilities of the cephalosporins were also evaluated by spectrophotometric assay using 21 different beta-lactamases. Bay v 3522 was the most potent cephalosporin overall against Gram-positive pathogens, but slightly less active than amoxicillin/clavulanate. In addition to being highly active against streptococci (MIC90 = 0.25 micrograms/ml) and methicillin-susceptible staphylococci (MIC90 = 1.0 micrograms/ml), Bay v 3522 was markedly more active than the other cephalosporins against Enterococcus faecalis (MIC90 = 4 micrograms/ml). Bay v 3522 was less potent against Gram-negative pathogens, especially nosocomial isolates of Escherichia coli and Klebsiella pneumoniae (MIC90 greater than 64 micrograms/ml), but was active against Haemophilus influenzae, Moraxella (Branhamella) catarrhalis, and beta-lactamase-negative Neisseria gonorrhoeae (MIC90 = 1.0 micrograms/ml0. Hydrolysis of Bay v 3522 by most beta-lactamases examined was significantly less than that observed for cephalothin and cefaclor; similar to that observed with cephalexin; and less than that observed with cefixime and cefuroxime. None of the beta-lactamases examined hydrolysed Bay v 3522 at a rate greater than 20 nmol/min/mg. The in vitro potency of Bay v 3522 against Gram-positive and fastidious Gram-negative pathogens and its resistance to hydrolysis by beta-lactamases produced by them support further investigation of this cephalosporin as a new oral therapeutic agent.     

Bacteriological study on fosfomycin against organisms clinically isolated from paranasal sinusitis

Multi-center bacteriological and clinical studies on fosfomycin (FOM) nasal solution were performed in subjects with paranasal sinusitis from January, 1988 to May, 1990. In these studies, we were exclusively responsible for bacterial isolation from clinical sources, bacterial identification and the determination of drug susceptibility. Before local administration of FOM nasal solution, many strains of various bacterial species were isolated from sources totalling 396 cases involved in phase II clinical studies, dose-finding and open clinical studies. From antibacterial activities of FOM against those isolates, we obtained the following conclusions. 1. Among the 447 isolates, Streptococcus spp. occupied 25.7%, Staphylococcus spp. 21.7% and anaerobic Gram-positive cocci (GPC) 13.6%, showing high detection frequency of aerobic and anaerobic GPC. Next to these, Haemophilus influenzae, Pseudomonas aeruginosa, Klebsiella spp. and Branhamella catarrhalis also were often obtained. 2. After exclusion of possibly contaminating strains which might have entered into cultures at samplings or transfers, the MIC50 and the MIC80 of FOM against the remaining 354 isolates were determined to be 12.5 and 25 micrograms/ml, respectively, indicating that local use of FOM would be fully effective to eradicate most of the bacteria. 3. FOM nasal solution showed sufficient eradication efficacy against most clinical isolates of possible causative organisms of paranasal sinusitis, and appeared to be useful as a topical preparation for the treatment of this disease.     

Fundamental and clinical studies on aztreonam in the pediatric field

Fundamental and clinical studies on aztreonam (AZT), a new monobactam antibiotic, were performed in the pediatric field. The MICs of AZT were assessed against the clinically isolated strains in the pediatric infections. AZT showed an excellent antibacterial activity against Gram-negative bacteria, i.e., against E. coli (20 strains), K. pneumoniae (9), P. mirabilis (16), P. vulgaris (5), P. aeruginosa (10), S. typhimurium (4) and H. influenzae (11); the MICs of AZT against the above strains were less than 0.39 microgram/ml, 0.10 microgram/ml, 0.024 microgram/ml, 0.024 microgram/ml, 6.25 micrograms/ml, 0.10 microgram/ml and 0.10 microgram/ml, respectively. However, antibacterial activity of AZT against Gram-positive bacteria was inferior to that against Gram-negative bacteria, i.e., against the strains of S. aureus (16) and S. pyogenes (4), those MICs were more than 400 micrograms/ml and 3.13 micrograms/ml, respectively. Serum concentrations and urinary excretion of AZT were measured in 2 children aged 7 and 11 years after a single intravenous injection at the dose of 20 mg/kg. The mean serum concentration of AZT followed by the injection 62.5 micrograms/ml at 1/4 hour, 28.5 micrograms/ml at 1/2 hour, 16.5 micrograms/ml at 1 hour, 12.0 micrograms/ml at 2 hours, 3.6 micrograms/ml at 4 hours and 1.1 micrograms/ml at 6 hours, respectively. The mean half-life (beta-phase) was 1.24 hours. The mean urinary concentrations after the injection were 5,000 micrograms/ml in 0-2 hours, 1,650 micrograms/ml in 2-4 hours and 611 micrograms/ml in 4-6 hours and the mean urinary recovery rate up to 6 hours was 61.2%. These results in our studies were considered to be comparable with those reported in adults. In our clinical studies, AZT was administered to a total of 14 cases, i.e., acute pneumonia (4 cases), acute pyelonephritis (4), acute enteritis (5) and acute sppurative cholangitis (1). Clinical effect of AZT was excellent or good in 13 cases except fair in 1 case with acute enteritis and the efficacy rate (excellent and good) was 92.9%. With regard to bacteriological effect, all the strains of H. influenzae (3), E. coli (2), P. mirabilis (1) and P. vulgaris (1) were eradicated, but, S. typhimurium (4) was not eradicated. Neither side effect nor abnormal laboratory findings were observed during the study.     

Amikacin: in vitro bacteriological studies, levels in human serum, lung and heart tissue, and clinical results

The amikacin sensitivity of bacteria cultured from 3282 clinical cases of mixed type was determined. Gentamicin and amikacin were equally effective against E. coli strains. Amikacin inhibited the growth of more Pseudomonas aeruginosa strains than did gentamicin. Against Gram-positive bacteria gentamicin proved to be more effective. Many of the gentamicin-resistant strains were sensitive to amikacin. Amikacin levels were measured during 21 pulmonary and 14 heart operations, subsequent to a intramuscular administration of 500 mg amikacin. The serum contained 17-20 microgram/ml amikacin, in the intact, inflamed and tumourous parts of removed lung tissue 9, 6 and 6 microgram/g concentrations were detected, respectively, whereas the cardiac auricle and the pericardial fluid contained 3-4 and 2-4 microgram/ml, respectively. These amikacin levels reach or in most cases even exceed the minimal inhibiting concentrations against the bacteria. Therefore, amikacin is excellent for the treatment of respiratory infections, pericarditis and endocarditis caused by Gram-negative, gentamicin-resistant bacteria. Amikacin treatment of 8 patients with grave diseases as well as the successful local administration of amikacin based on the therapy of 55 cases of surgical suppurations is reported.     

Evaluation of latamoxef in neonates

Basic and clinical studies were carried out on latamoxef (LMOX) in relation to the use of this antibiotic in the treatment of infections in newborn infants. The results were as follows. The MICs of LMOX were determined for various clinical isolates of Gram-negative bacteria: 22 strains of E. coli, 18 strains of K. pneumoniae, 4 strains of K. oxytoca, 19 strains of P. mirabilis, 4 strains of P. vulgaris, 5 strains of P. morganii and 3 strains of C. freundii and 60 strains of H. influenzae. The MIC distributions against all of these strains for each species were 0.1, 0.2, 0.1, 0.2, 0.1, 0.1, 6.25 and 0.78 microgram/ml or less, respectively. The antibacterial activity of LMOX against all of these Gram-negative isolates was thus found to be excellent. For 38 strains of P. aeruginosa, the MIC distribution was from 6.25 to 200 micrograms/ml; accordingly, although this antibiotic does show antibacterial activity against this microbe, it is not very potent. As Gram-positive bacteria, 28 clinical isolates of S. pyogenes and 34 strains of S. aureus were tested; their respective MIC distributions were 0.39--1.56 micrograms/ml and 3.13--25 micrograms/ml. Therefore, it is clear that the antibacterial activity of LMOX against these Gram-positive bacteria is not as good as against the above-mentioned Gram-negative species. LMOX was injected intravenously as a one-shot dose of 20 mg/kg to 5 newborn infants (ranging in age from 0 to 13 days) and to 2 suckling infants (49 and 60 days of age), and then the concentration of the drug in the serum was monitored with time. The mean serum concentrations in the newborn group at various times were as follows: 38.5 micrograms/ml at 0.5 hour, 31.6 micrograms/ml at 1 hour, 26.9 micrograms/m l at 2 hours, 17.8 micrograms at 4 hours and 15.5 micrograms/ml at 6 hours. For the 2 suckling infants, the mean values at those same time points were 30.5, 23.9, 16.3, 7.4 and 4.0 micrograms/ml. In addition the value for the mean serum half-life was 4.46 hours in the newborn infant group and 1.96 hours in the suckling infant group. The urinary recovery rate was 32.3% in the newborn infant group and 49.7% in the suckling infant group during 6 hours or 8 hours.(ABSTRACT TRUNCATED AT 400 WORDS)     

Fundamental and clinical studies on T-1982 (cefbuperzone), a new cephamycin antibiotic, in the field of pediatrics

Studies on T-1982 (cefbuperazone), a new cephamycin antibiotic, were carried out in the field of pediatrics, and the following results were obtained. 1. Peak MIC of T-1982 against S. pyogenes (group A) lately isolated was 0.39 micrograms/ml, and the drug was active even against highly resistant strains of macrolides, lincomycin, tetracycline and chloramphenicol. 2. Peak MICs of T-1982 were 0.78 microgram/ml against B. pertussis, 0.2 microgram/ml against E. coli and less than or equal to 0.05 microgram/ml against K. oxytoca, and the drug was also active against ampicillin-resistant bacteria. 3. Serum levels and urinary excretions of T-1982 were investigated in 6 cases. When given at a dose of 20-28 mg/kg by 1 hour intravenous drip infusion, serum concentrations of T-1982 attained the peak level of 63.5-75.9 micrograms/ml at the end of administration and sustained the level of 0.9-2.6 micrograms/ml at 6 hours, the serum half-life (T 1/2) ranging 70-82 minutes. Approximately 20-72% of the dose were excreted in the active form into urine within 6 hours. 4. Twenty-seven cases of acute pediatric infections were treated with T-1982 mainly by intravenous drip infusion, and satisfactory clinical results were obtained in all the cases of angina lacunaris, bronchitis, bronchopneumonia, pertussis, sepsis caused by Serratia and acute urinary tract infections caused by ampicillin-resistant E. coli. The efficacy rate was 96.3%. In this study the drug was administered chiefly at a daily dose of 50-70 mg/kg 2-3 times a day for 2-12 days. 5. Gram-positive cocci (S. aureus, S. pneumoniae, S. pyogenes) and Gram-negative rods (H. influenzae, H. parainfluenzae P. vulgaris, B. pertussis, S. marcescens, E. coli) were eradicated by the treatment with T-1982. 6. No noticeable side effects were observed, except for temporary increase of eosinophil in 2 cases and slight elevation of GOT in 1 case.     

Pharmacokinetic and clinical studies on cefprozil granules in the pediatric field]

Cefprozil (CFPZ), a newly developed oral cephalosporin in a fine granular form for pediatric use, was administered to children with bacterial infections. MICs were determined for 6 drugs including CFPZ, cephalexin (CEX), cefaclor (CCL), ampicillin (ABPC), methicillin (DMPPC) and cloxacillin (MCIPC) against the following 84 strains isolated from cases to which CFPZ was administered; 55 strains of Gram-positive cocci (GPC) including 2 strains of Staphylococcus aureus, 49 strains of Streptococcus pyogenes, 4 strains of Streptococcus pneumoniae, and 29 strains of Gram-negative bacilli (GNB) including 10 strains of Haemophilus influenzae, 18 strains of Escherichia coli, and 1 strain of Proteus mirabilis. MIC determination of these strains was done with an inoculum size of 10(6) CFU/ml. In pharmacokinetic studies, serum concentrations, urinary concentrations and urinary recovery rates were investigated using bioassay and high-performance liquid chromatography (HPLC). CFPZ was orally administered 30 minutes before meals to 9 children with ages ranging from 7 years and 1 month to 12 years and 3 months. Three groups of 3 children were tested with doses of 4.0, 7.5 and 15.0 mg/kg, respectively. In addition to the above, clinical and bacteriological studies were performed in a total of 160 cases consisting of children with ages ranging 5 months to 12 years and 5 months. A mean dose of 8.6 mg/kg in 3-4 divided doses (130 cases of t.i.d. and 30 cases of q.i.d.) was administered for an average of 7 days. The 160 cases included 34 cases of pharyngitis, 5 cases of tonsillitis, 8 cases of acute bronchitis, 8 cases of pneumonia, 52 cases of scarlet fever, 4 cases of acute purulent otitis media, 47 cases of urinary tract infection, 1 case of purulent lymphadenitis and 1 case of posthitis. Adverse reactions and abnormal clinical laboratory test results were also examined in 166 cases, including 6 cases excluded from the evaluation of clinical efficacy. The results obtained are summarized as follows: 1. With regard to GPC, MICs of CFPZ against 2 strains of S. aureus were 0.78 or 1.56 micrograms/ml and CFPZ showed the second highest activity to MCIPC. MICs of CFPZ against 49 strains of S. pyogenes were all less than 0.025 micrograms/ml.(ABSTRACT TRUNCATED AT 400 WORDS)     

Basic and clinical study of meropenem in pediatric field]

Meropenem (MEPM), a novel parenteral carbapenem antibiotic, was examined in a cooperative study involving 12 pediatric and 1 neonatologic facilities. The results are summarized as follows. 1. Antibacterial activity Antibacterial activity of MEPM against stock organisms including 31 strains of Streptococcus agalactiae, 14 of Listeria monocytogenes, 4 of Bordetella pertussis and 3 of Neisseria meningitidis ranged from 0.025 to 0.10 micrograms/ml in MIC90's, which were equal or lower than those of control drugs such as imipenem cefazolin, cefotiam, cefotaxime, ceftazidime and latamoxef. MICs against clinical isolates were as follows: In Gram-positive bacteria, MICs were 0.20 micrograms/ml to 6.25 micrograms/ml against 3 strains of Staphylococcus aureus, and 0.025 micrograms/ml or less against 4 of Streptococcus pneumoniae. In Gram-negative bacilli, MICs were 0.10 micrograms/ml to 0.20 micrograms/ml against 3 strains of Haemophilus influenzae and 0.78, 0.10 and 0.78 micrograms/ml, respectively, against one strain each of Enterobacter cloacae, Morganella morganii and Pseudomonas aeruginosa. MIC against 1 strain of Peptococcus saccharolyticus was < or = 0.025 micrograms/ml. 2. Pharmacokinetics Maximum plasma concentrations after intravenous infusion of MEPM over 30 minutes at doses of 10, 20 and 40 mg/kg, respectively, to 3 different groups of 3 children (total 9 cases) were observed at the completion of the treatment. Mean maximum concentrations in the 3 groups were 36.3, 69.5 and 129.8 micrograms/ml, respectively, exhibiting clear dose response. Mean plasma half lives in beta phase were 0.94, 0.86 and 0.94 hours, respectively, exhibiting no difference by doses, and this trend was observed also by HPLC. Urinary excretion rates in the first 6 hours after dose in the 10, 20 and 40 mg/kg groups were 67.3, 65.6 and 68.4%, respectively. Concentrations of MEPM in cerebrospinal fluid were determined in 2 cases of pyogenic meningitis. In 1 case, 500 mg (5.9 mg/kg) of MEPM was infused intravenously over 30 minutes and concentrations on Days 6, 8 and 15 observed at 190, 60 and 100 minutes after respective doses were 0.13, 0.10 micrograms/ml and less than the detection limit. Cerebrospinal fluid-plasma concentration ratio was determinable only on Day 8 and was 2.8%. In another case to which 250 mg (38.5 mg/kg) of MEPM was infused intravenously over 30 minutes, the concentration at Days 6, 7 and 10, 1 hour after the dose were less than the detection limit on day 6, and 2.04 and 2.62 micrograms/ml, respectively on days 7 and 10. 3. Clinical efficacy Clinical efficacies were evaluated in 49 cases and the efficacy rate was 93.9%.(ABSTRACT TRUNCATED AT 400 WORDS)     

Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (2000). I. Susceptibility distribution

The bacterial strains isolated from patients diagnosed as having urinary tract infections (UTIs) in 10 institutions in Japan were supplied between the period of August 2000 and July 2001. Then, the susceptibilities of them to many kinds of antimicrobial agents were investigated. The number of them were 511 strains. The breakdown of these strains was Gram-positive bacteria as 29.0% and Gram-negative bacteria as 71.0%. Susceptibilities of these bacteria to antimicrobial agents were as follows; vancomycin (VCM), ampicillin (ABPC) and imipenem (IPM) showed strong activities against Enterococcus faecalis. No increase in low-susceptible strains of E. faecalis observed against these antimicrobial agents. VCM showed a strong activity against MRSA preventing growth of all strains with 1 microgram/ml. In addition, the activity of arbekacin (ABK) was strong with the MIC90 of 2 micrograms/ml against MRSA and prevented growth of all strains with 4 micrograms/ml. ABK showed a strong activity against Staphylococcus epidermidis preventing growth of all strains with 0.5 microgram/ml. ABPC, cefotiam (CTM) and cefozopran (CZOP) also showed a relatively strong activity against S. epidermidis (MIC90: 4 to 8 micrograms/ml). Against Escherichia coli, carbapenems showed high activities: meropenem (MEPM) prevented growth of all strains within 0.125 microgram/ml; IPM prevented growth of all strains with 0.25 microgram/ml. CZOP and CTM also showed strong activities against E. coli: MIC90 of CZOP was within 0.125 microgram/ml; MIC80 and MIC90 of CTM were 0.25 and 0.5 microgram/ml, respectively. Quinolone resistant E. coli was detected at frequency of 14.0%, which was significantly higher than that in the last year. Almost all drugs showed strong activities against Klebsiella pneumoniae and Proteus mirabilis, and MEPM prevented growth of all strains within 0.125 microgram/ml. Against Pseudomonas aeruginosa, almost drugs were not so active. The MIC90 of carbapenems and gentamicin (GM) were 16 micrograms/ml and those of all other drugs were more than 32 micrograms/ml. Against Serratia marcescens, the MIC90 of IPM and GM were the lowest value being 2 micrograms/ml, and that of MEPM was 4 micrograms/ml.     

Bacteriological, pharmacokinetic and clinical evaluations of cefpirome sulfate in the pediatric field. Pediatric Study Group of Cefpirome

A research group was organized with the purpose of making basic and clinical studies on cefpirome sulfate (HR810, CPR), a newly developed cephalosporin antibiotic, in the pediatric field. Through meetings a joint research was done involving 19 key institutions and their related facilities throughout Japan. The obtained results are summarized as follows. 1. Antibacterial Activities Minimum inhibitory concentrations (MICs) were determined against 71 Gram-positive and 110 Gram-negative bacteria in the present clinical trials. CPR showed antibacterial activities 2-16 times higher than those of ceftazidime (CAZ) against Staphylococcus aureus and other Gram-positive bacteria including MRSA. Against Gram-negative bacteria, CPR showed a somewhat broad range of distribution in MIC against Branhamella catarrhalis, while the antibiotic inhibited the growth of all the strains of Escherichia coli and Haemophilus influenzae at concentrations no more than 0.10 and 0.20 micrograms/ml, respectively. 2. Blood Concentrations and Urinary Excretion Rates The pharmacokinetics in pediatric patients was investigated with a dose of 20 mg/kg in most cases via one shot intravenous injection or 30- and 60-minute intravenous drip infusion. Mean blood concentrations of CPR at 15 minutes after one shot intravenous injection of 10, 20, and 40 mg/kg were 51.2, 70.5, and 123.5 micrograms/ml, with half-lives of 1.21, 1.39, and 1.53 hours, respectively. Urinary excretion rates in 6 hours were 63.6, 66.0 and 71.6%, respectively for the 3 dose levels. After 30- and 60-minute intravenous drip infusions at the same dose, the pharmacokinetic parameters observed were similar to those obtained with one shot injections. 3. Concentration in the Cerebrospinal Fluid CPR penetrated well into the cerebrospinal fluid in patients with purulent meningitis and levels of 1.85-24.2 micrograms/ml 45-60 minutes were achieved after intravenous injection at a dose of 40-80 mg/kg, the penetration rate of CPR was at an intermediate degree compared with other cephalosporin antibiotics. 4. Clinical Results Clinical efficacies of CPR on infectious diseases were analyzed in 454 plus 3 cases which were complicated with other infectious diseases, hence totaling 457 cases out of 499 cases originally chosen for clinical evaluation. The remaining 45 cases were excluded from the clinical evaluation. As for the clinical efficacy, CPR was found to be effective (good or excellent) in 430 (94.1%) of the 457 cases. CPR was found to be effective in 243 (95.3%) of 255 cases for which causative bacteria were identified. The efficacy rate was 92.6% (187 of 202) in those cases in which causative bacteria were not identified.(ABSTRACT TRUNCATED AT 400 WORDS)     

Synthesis of some benzimidazole derivatives and their antibacterial and antifungal activities.

A number of new benzimidazole derivatives were synthesized by the reaction of benzimidazole with appropriate alkyl halides. The compounds synthesized were intensified by 1H-NMR, Fourier Transformation Infrared (FT-IR) and micro analysis. All new and related compounds studied in this work were screened for their in vitro antimicrobial activities against the standard strains: Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and the yeasts Candida albicans and Candida tropicalis. Eleven of the compounds were found effective to inhibit the growth of Gram-positive bacteria (E. faecalis and S. aureus) at MIC values between 12.5-400 micrograms/ml. None of the compounds exhibited antimicrobial activity against Gram-negative bacteria (E. coli and P. aeruginosa) at the concentrations studied (6.25-800 micrograms/ml). All compounds (except compound 3) were significantly effective against C. tropicalis with MIC values of 6.25-400 micrograms/ml. Eight of the tested compounds showed an antifungal activity against C. albicans with a range of the MICs between 50 and 400 micrograms/ml.     

Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1999). I. Susceptibility distribution

The bacterial strains isolated from patients diagnosed as having urinary tract infections (UTIs) in 9 institutions in Japan were supplied between the period of August 1999 to July 2000. Then, the susceptibilities of them to many kinds of antimicrobial agents were investigated. The number of them were 499 strains. The breakdown of these strains was Gram-positive bacteria as 31.3% and Gram-negative bacteria as 68.7%. Susceptibilities of these bacteria to antimicrobial agents were as follows; vancomycin (VCM), ampicillin (ABPC) and imipenem (IPM) showed strong activities against Enterococcus faecalis. The increase of low-susceptible strains which was noticed in the former year showed a slight recovery in this year. VCM showed a strong activity against MRSA preventing growth of all strains with 1 microgram/ml. In addition, the activity of arbekacin (ABK) was also strong with the MIC90 of 2 micrograms/ml against MRSA. However, MSSA and MRSA showing low susceptibilities were detected in one strain each (MIC: 16 micrograms/ml and 32 micrograms/ml, respectively). Carbapenems showed high activities against Citrobacter freundii and Escherichia coli. Meropenem (MEPM) prevented growth of all strains within 0.125 microgram/ml. Quinolone resistant E. coli decreased in this year compared with those in the last year, that percentage was less than 5%. Almost all drugs showed strong activities against Klebsiella pneumoniae and Proteus mirabilis. MEPM and carumonam (CRMN) prevented growth of all strains within 0.125 microgram/ml. On the other hand, one strain of K. pneumoniae showing resistance to cefaclor (CCL) and one strain of P. mirabilis showing low susceptibility to most of cephems were detected. Against Pseudomonas aeruginosa, almost drugs were not so active. The MIC90s of carbapenems were 8 micrograms/ml and those of all other drugs were more than 16 micrograms/ml.