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S Fukayama

Publications and source records attributed to S Fukayama.

At least 109 records · Page 6Linked to original sources

[Measurement of MICs on 16 antimicrobial agents for freshly isolated methicillin-resistant Staphylococcus aureus strains].

MICs of 16 antimicrobial agents including a newly synthesized aminoglycoside antibiotic, arbekacin (HBK), were determined against methicillin-resistant Staphylococcus aureus (MRSA) strains which had been isolated since 1988 from patients with refractory infections. 1. The proportion of highly methicillin-resistant strains was large, especially among those isolated from blood and respiratory tract. 2. All the MRSA strains were resistant to all the beta-lactam antibiotics tested. 3. Most of the strains were also resistant to aminoglycosides. However, HBK inhibited the growth of 95% of the strains at 3.13 micrograms/ml or less, showing potent activities even against highly resistant MRSA strains. 4. The MIC distribution of HBK against MRSA strains showed no change since 1986 when year to year data were compared. Based on our studies on the drug resistance pattern of MRSA since 1986, a large proportion of MRSA strains isolated from blood and respiratory tract appeared to be coagulase type II. 5. Netilmicin-resistant MRSAs have increased since 1986, and MRSA resistant to fosfomycin, minocycline, ofloxacin and norfloxacin have also increased in 1989 compared to 1988. 6. The drug resistance pattern of MRSA has been changing every year and they are acquiring multi-drug resistance. Thus, in the treatment of MRSA infections, it is very important to identify the drug susceptibility of MRSA quickly and accurately.

Aminoglycosides↗

Direct modulation by estradiol of the response of human bone cells (SaOS-2) to human parathyroid hormone (PTH) and PTH-related protein.

We have investigated the actions of 17 beta-estradiol (E2) on the production of cAMP stimulated by synthetic human PTH [hPTH-(1-34)], synthetic hPTH-related protein [hPTHrP-(1-34)], and vasoactive intestinal peptide (VIP) in human (SaOS-2) and rat (ROS 17/2.8) osteoblast-like osteosarcoma cells. In SaOS-2 cells, hPTH-(1-34) (2.5 nM), hPTHrP-(1-34) (2.5 nM), and VIP (10-100 nM) stimulated the accumulation of cAMP markedly (greater than 20- to 30-fold in 1 h). Cells were preincubated in serum-free medium for 4-24 h, then in the absence or presence of E2 for 4 h before a 1-h stimulation with peptide hormone in the absence of E2. In SaOS-2 cells, pretreatment with E2 (10(-12)-10(-8) M) for 4 h inhibited by up to 50% the accumulation of cAMP stimulated by hPTH-(1-34) or hPTHrP-(1-34), but E2 had no inhibitory effect on VIP action. 17 alpha-Estradiol had no inhibitory action on hPTH- or hPTHrP-stimulated accumulation of cAMP at concentrations as high as 10(-8) M. Additional evidence against a nonspecific effect of E2 was the total lack of inhibition of cAMP accumulation stimulated by hPTH-(1-34) or hPTHrP-(1-34) in ROS 17/2.8 cells at concentrations of E2 up to 10(-6) M. We conclude that E2 can act directly and rapidly in human osteoblast-like cells to modulate selectively the ability of hPTH and hPTHrP to enhance the production of cAMP.

Animals↗

Direct modulation by androgens of the response of human bone cells (SaOS-2) to human parathyroid hormone (PTH) and PTH-related protein.

We have reported previously that 17 beta-estradiol (E2) inhibits selectively the cAMP response to human (h) PTH and PTH-related protein (hPTHrP), but not to vasoactive intestinal peptide, in human osteoblast-like cells (SaOS-2). We have now extended these studies to investigate the actions of androgens on hPTH-stimulated accumulation of cAMP, and on the roles of new protein synthesis and pertussis toxin (PTox) substrates in the actions of steroid hormones on SaOS-2 cells. Pretreatment with testosterone (T) or 5 alpha-dihydrotestosterone (5 alpha-DHT) for 4-12 h at concentrations of 10(-12) to 10(-8) M inhibited significantly the cAMP response to hPTH by up to 50-70% of control. Like E2, the actions of T and 5 alpha-DHT were selective for hPTH or hPTHrP; there was no inhibition of the stimulatory action of vasoactive intestinal peptide. Two related steroids, 5 beta-DHT and 17 alpha-epitestosterone, did not inhibit the action of hPTH. Pretreatment of cells with cycloheximide, under conditions which inhibited protein synthesis by greater than 90%, reduced the cAMP response to hPTH but did not block the further inhibitory actions of E2, T, or 5 alpha-DHT. Pretreamtent of cells with PTox (100 ng/ml) for 24 h, enhanced the accumulation of cAMP stimulated by hPTH consistent with an action of PTox on Gi; however, the inhibitory actions of E2, T, and 5 alpha-DHT on PTH-stimulated cAMP accumulation were not attenuated by PTox. We conclude that androgens, as well as estrogens, act directly on human bone cells to modulate selectively an early effect of hPTH. The inhibitory actions of these steroid hormones do not appear to depend on new protein synthesis and may not involve a functionally active PTox substrate, presumably Gi.

Androgens↗

[Determination of the MIC of cefotetan against freshly isolated gram-negative bacilli].

Antimicrobial activities (MICs) of cefotetan (CTT) against 575 strains of 16 spp. of Gram-negative bacilli isolated in 1988 were determined to investigate distribution of MICs in comparison with those of cefmetazole (CMZ), cefoxitin (CFX), latamoxef (LMOX) and cefazolin (CEZ). The change in frequencies of incidence of cephem-resistant strains in the latter half of the 1980 was also investigated. Distribution of MIC of CTT varied with test strains. No or very few MICs were at or higher than 12.5 micrograms/ml at an inoculation of 10(6) cfu/ml, thus rates of CTT-resistant strains were low among Escherichia coli, Citrobacter diversus, Klebsiella spp., Proteus spp., Providencia spp., and Haemophilus influenzae. High rates of resistance to CTT were observed, however, among Citrobacter freundii, Enterobacter spp., Serratia marcescens, Morganella morganii, and Bacteroides fragilis. 2. Most CTT-resistant strains of C. freundii, Enterobacter spp. and S. marcescens were also resistant to LMOX. These resistant strains were considered to be multi-resistant strains to antibiotics including oxime type cephalosporins and monobactams. 3. Cephem-resistant E. coli was confirmed to be resistant to 22% of CEZ, 14% of CFX, 10% of CMZ and 2% of CTT tested. The incidence of cephem-resistant E. coli unconditionally showed an increasing tendency. 4. The incidence of resistant strains against cephamycins including CTT is discussed with regard to the mechanism of resistance against all beta-lactam antibiotics, and the problem of the appearance of resistant strains is close and inseparable from social background.

Cefazolin↗

[Antimicrobial activity of cefteram comparison with other oral antibiotics].

Antimicrobacterial activities of cefteram (CFTM) against clinical isolates collected in 1988 were compared with those of new beta-lactams. 1. Antibacterial activities of CFTM against Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae, Branhamella catarrhalis isolated from acute respiratory tract infections were 8- to 16-fold higher than those of cefaclor (CCL). 2. Activities of cefixime (CFIX) were superior to those of CFTM against B. catarrhalis, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, but were inferior to CFTM against S. pneumoniae, S. pyogenes, Staphylococcus saprophyticus and Staphylococcus aureus. 3. Activities of cefuroxime were superior to those of CCL against each of the 4 tested bacterial species from acute respiratory tract infection and S. aureus by 4-fold, but were inferior to CFTM and CFIX against most of Gram-negative rods. 4. Sultamicillin (SBTPC) is considered to have an activity to inhibit beta-lactamase, but its MICs did not exceed the MICs of ampicillin by itself. SBTPC showed poor antibacterial activities against methicillin-resistant S. aureus (MRSA). Considering these observations, it is apparent that we are faced with a variety of factors in selecting antibiotics for best results.

Ampicillin↗

Human parathyroid hormone (PTH)-related protein and human PTH: comparative biological activities on human bone cells and bone resorption.

Human PTH-related protein (hPTHrP) has been characterized as a product of tumor cells with sequence homology to the biologically active amino-terminal portion of human PTH (hPTH). We measured the relative activities of synthetic amino-terminal sequences of hPTH-(1-34) and hPTHrP-(1-34) to stimulate production of cAMP in intact human SaOS-2 osteosarcoma cells. Both peptides enhanced cAMP production at concentrations of 2.5-7.5 X 10(-10) M, had parallel dose-response curves, and were of essentially equal potency. Preincubation of SaOS-2 cells with hPTH-(1-34) or hPTHrP-(1-34) for 1 or 4 h induced homologous desensitization to a second challenge with the same peptide as well as heterologous desensitization to the other PTH peptide, but had little or no effect on the action of vasoactive intestinal peptide; the magnitudes of homologous and heterologous desensitization induced by the same doses of hPTHrP-(1-34) or hPTH-(1-34) were similar. Bone resorption-stimulating activity was measured using 40Ca2+ release from neonatal mouse calvariae in organ culture after 72 h of incubation. hPTHrP-(1-34) gave a dose-response between 0.2 and 5 ng/ml (5 X 10(-11) and 1.2 X 10(-9) M), was about 3 times more potent than Lilly bovine PTH standard (assuming a SA of 3000 U/mg; 100 U/ml), gave the same maximum response as hPTH-(1-34), and was 20-30% as potent as hPTH-(1-34). Neither hPTH-(1-34) nor hPTHrP-(1-34) enhanced prostaglandin production in mouse calvariae, and indomethacin did not inhibit the bone resorption-stimulating activities of either peptide. We conclude that hPTHrP-(1-34) and hPTH-(1-34) have similar high specific biological activities to stimulate production of cAMP in human osteoblast-like cells, but that hPTHrP-(1-34) is modestly less potent than hPTH-(1-34) to stimulate bone resorption in mouse calvariae.

Animals↗

[Antibacterial activities of monobactams against fresh clinical isolates].

Antibacterial activities of monobactam antibiotics (carumonam (CRMN) and aztreonam (AZT] against Gram-negative bacilli isolated from inpatients in the latter half of 1987 were investigated using penicillin (PC: piperacillin (PIPC], cephems (CEPs: ceftazidime (CAZ), cefotaxime (CTX), latamoxef (LMOX), cefsulodin (CFS], carbapenem (imipenem (IPM] and pyridonecarboxylic acids (norfloxacin (NFLX) and ofloxacin (OFLX] as reference antibiotics. A total of 400 strains of 13 species, i.e. Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis, Proteus vulgaris, Morganella morganii, Providencia rettgeri, Citrobacter freundii, Enterobacter cloacae, Enterobacter aerogenes, Serratia marcescens, Pseudomonas aeruginosa and Haemophilus influenzae, were used as test strains. 1. CRMN and AZT, both monobactam antibiotics, were roughly comparable in their activities and no resistant strain to these antibiotics were found among isolates of E. coli, Klebsiella spp., Proteus spp., M. morganii, P. rettgeri or H. influenzae and few resistant strains were observed among isolates of S. marcescens. On the other hand, isolates of C. freundii, Enterobacter spp. and P. aeruginosa included rather numerous strains resistant to the monobactam antibiotics. Among these cases, whereas R strains, i.e. resistant strains showing MICs greater than or equal to 50 micrograms/ml, accounted for a large proportion of strains resistant to PC and CEPs, I strains, i.e. intermediately resistant strains showing MICs between 12.5 and 25 micrograms/ml, accounted for a large proportion of strains resistant to the monobactam antibiotics. 2. Strains resistant to PIPC, a PC, were detected with high and more or less uniform frequencies over the entire spectrum of the isolates examined. 3. Antibacterial activities of CEPs varied against different bacterial species. While strains resistant to CTX, CAZ and LMOX were commonly detected with high frequencies among isolates of C. freundii, Enterobacter spp. and S. marcescens, large percentages of LMOX-resistant strains of C. freundii and Enterobacter spp. were of the I type. CTX-resistant strains were also found among isolates of P. vulgaris and M. morganii. Proportions of CEP-resistant strains of P. aeruginosa were 28% for CFS and 12% for CAZ. 4. No or few strains among the isolates of 13 species investigated were resistant to IPM, a carbapenem antibiotic, which showed the most stable antibacterial activity, but it was less active than monobactam antibiotics and CEPs against Klebsiella spp., P. mirabilis and H. influenzae.(ABSTRACT TRUNCATED AT 400 WORDS)

4-Quinolones↗

[Antibacterial activity of gentamicin against clinical isolates in pediatrics].

Antibacterial activity of gentamicin (GM), along with activities of other aminoglycosides and beta-lactams, was studied against clinical isolates collected from pediatric patients during a period of May 1986-April 1987. 1. GM-resistance was noted in 22% of Staphylococcus aureus, 6% of Proteus vulgaris, 8% of Morganella morganii, 40% of Providencia spp., 6% of Enterobacter spp., 14% of Serratia marcescens, and 14% of Pseudomonas aeruginosa isolates. No GM-resistance was observed with isolates of Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. 2. The antibacterial activity of GM against clinical isolates from pediatric patients was found to be comparable to its activity against clinical isolates from adults studied at the same time. 3. The majority of GM-resistant strains of S. aureus were MCRSA, and the GM-resistant strains of S. marcescens and P. aeruginosa were found also to be resistant to multiple drugs. 4. GM-resistant strains were found at relatively high rates (14-22%) in S. aureus, S. marcescens and P. aeruginosa. These rates did not increase compared to the rates observed in the first half of the 1980's. 5. GM was considered to have poor antibacterial activity against genus Providencia. It is concluded from above results that GM still maintains effective antibacterial activity against many of causative organisms of infections in both adults and children.

Anti-Bacterial Agents↗

[Antimicrobial activities of sultamicillin against clinical isolates from upper respiratory tract infections].

Sultamicillin (SBTPC) is a mutual prodrug in which ampicillin (ABPC) and a potent beta-lactamase inhibitor sulbactam (SBT) are ester-bound in an equimolar ratio. SBTPC is hydrolyzed during absorption after oral administration to provide ABPC and SBT for systemic circulation. In the present study, the antimicrobial activities of SBTPC against 50 isolates each of 6 species (Staphylococcus aureus, Klebsiella pneumoniae subsp. pneumoniae, Branhamella catarrhalis, Haemophilus influenzae, Streptococcus pneumoniae and Streptococcus pyogenes) of bacteria freshly obtained from upper respiratory tract infections were examined in relation to their bacterial beta-lactamase producing abilities. beta-Lactamase producing strains were identified using the acidometry disc method with benzylpenicillin (PCG) of cefazolin (CEZ) as a substrate, and their frequencies of appearance were calculated as follows: S. aureus 86%; K. pneumoniae subsp. pneumoniae 100%; B. catarrhalis 68%; H. influenzae 24%. Fourteen per cent of S. aureus strains examined were beta-lactamase positive using both PCG and CEZ acidometry discs. SBTPC, however, demonstrated excellent antimicrobial activities even against these beta-lactamase producing strains. Good activities were observed especially against those bacterial strains producing penicillinase (PCase). Average MIC80 values of SBTPC were 3.13 micrograms/ml for S. aureus and K. pneumoniae subsp. pneumoniae, 0.39 micrograms/ml for B. catarrhalis and H. influenzae, 0.05 micrograms/ml for S. pneumoniae and 0.025 micrograms/ml for S. pyogenes. As SBTPC was shown to possess excellent antimicrobial activities against PCase producing strains, the enhancement in activities of SBTPC compared to ABPC alone can be attributed to the inhibition of beta-lactamase by SBT which, as noted above, is a component of SBTPC in an equimolar ratio to ABPC.

Acute Disease↗

[Antimicrobial activity of sultamicillin against clinical isolates from upper respiratory tract infections II].

In an attempt to examine the effect of sulbactam (SBT) on beta-lactamase activity, three hundred clinical isolates from the infected upper respiratory tract were tested for MICs and disk sensitivities of ampicillin (ABPC) and sultamicillin (SBTPC). beta-lactamase production was tested using the acidometry disk method (beta-Check, Taito Pfizer Co.). For strains such as Klebsiella spp. which form mucoid type colonies, we used the SS culture medium which, by reducing the influence of huge amounts of capsular material, allows a better reaction to the acidometry disk. Penicillinase, produced by Branhamella catarrhalis, Haemophilus influenzae, Neisseria spp., etc. was detected clearly by direct application of portions of colonies onto acidometry disks. For cephalosporinase, however, a direct application of such fractions resulted in weak reactions. We, therefore, used fractions which had undergone the enzyme induction, and obtained better reactions. Sensitivities of tested bacteria to ABPC and SBTPC were inversely related to MIC values. beta-Lactamase-producing strains showed weaker sensitivity to ABPC than non-producing strains. To SBTPC, however, beta-lactamase-producing strains and non-producing strains showed very similar sensitivity. We thus confirmed that the inhibitory action of SBT to beta-lactamase can well be demonstrated using the disk sensitivity method.

Ampicillin↗

[The antimicrobial activity of sisomicin against fresh clinical isolates].

Antimicrobial activities of sisomicin (SISO) against clinical isolates obtained in the second half of 1986 were investigated together with other 4 aminoglycosides (AGs) (gentamicin (GM), tobramycin (TOB), dibekacin (DKB), amikacin (AMK] and 2 cephems (cefotiam, cefotaxime), and were compared to the results reported in the period of late 1970's through early 1980's in Japan. 1. The incidence of SISO-resistant Staphylococcus aureus in the present study was 18% and is comparable to that of the other studies suggesting that the incidence of SISO resistant strains remains on the stable level. The incidence of SISO-resistant Pseudomonas aeruginosa showed the tendency of slight increase. 2. SISO-resistant strains of Enterobacter spp., Serratia marcescens and Citrobacter freundii did not show increase from the 1970/1980 levels. 3. Isolation rates of SISO-resistant indole(+) Proteus varied depending on strains. Isolation rates of SISO-resistant P. vulgaris and Morganella morganii were both as low as 4%, but that of Providencia rettgeri was as high as 60%. Refering to an American study reporting that the Genus Providencia including P. rettgeri showed high incidence of resistance to SISO as well as to GM or TOB, we pointed out that the antimicrobial activity of AGs against Genus Providencia should be evaluated separately from those of other indole(+) Proteus strains. 4. No SISO-resistant strains of Escherichia coli, Klebsiella pneumoniae or P. mirabilis were found. 5. SISO had good antimicrobial activity against most of the investigated species and SISO may still be regarded as one of the clinically useful AGs.

Bacterial Infections↗

[Antimicrobial activity of sulbactam/cefoperazone. Comparison with other new cephems].

Antimicrobial activities of sulbactam/cefoperazone (SBT/CPZ) against 50 fresh clinical isolates of Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Citrobacter freundii, Enterobacter spp., Serratia marcescens, Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa were compared to those of CPZ, Cefotiam (CTM), Cefotaxime (CTX) and Latamoxef (LMOX). Minimal inhibitory concentrations (MIC's) of SBT and CPZ mixed in a ratio of 1:1 were determined by the dilution method using Mueller-Hinton agar and expressed by absolute concentrations of CPZ. Antimicrobial activities of SBT/CPZ against principally penicillinase (PCase) producing bacteria, i.e., S. aureus, E. coli, K. pneumoniae, P. mirabilis, were superior to those of CPZ alone. The presence of SBT in concentrations around 0.39 approximately 1.56 micrograms/ml clearly enhanced CPZ's antimicrobial activities against these PCase producing strains. The synergistic antimicrobial effects of SBT in combination with CPZ were less pronounced against principally cephalosporinase (CEPase) producing bacteria, i.e., C. freundii, Enterobacter spp., S. marcescens, P. vulgaris, and P. aeruginosa, and exerted with SBT at concentrations around 3.13 approximately 12.5 micrograms/ml. Comparative antimicrobial activities indicated by MIC80's of tested agents showed that SBT/CPZ had more stable activities against bacteria ranging from Gram-positive to Gram-negative bacteria than CTM, CTX and LMOX. MIC's of SBT/CPZ were higher than 25 micrograms/ml against 8% of S. aureus, 18% of C. freundii, 10% of Enterobacter spp., 26% of S. marcescens, 2% of P. vulgaris, and 18% of P. aeruginosa. These resistant strains against which the addition of SBT showed no synergism, may possess other mechanism of resistance than beta-lactamase production. It is concluded that the presence of CPZ resistant strains is an actual current problem and not an imaginary future problem, and that the number of resistant strains against other new cephems which have different chemical structure from CPZ is increasing. When these present bacteriological environments are considered, the appearance of SBT/CPZ in the clinical practice is timely and meaningful.

Bacteria↗

[Antibacterial activities of various aminoglycosides against clinically isolated methicillin-resistant Staphylococcus aureus].

Methicillin-resistant Staphylococcus aureus (MRSA) were isolated from samples collected from various patients during 1986, and antibacterial activities of 6 aminoglycosides (AGs) (netilmicin (NTL), gentamicin (GM), sisomicin (SISO), dibekacin (DKB), tobramycin (TOB) and amikacin (AMK] and 4 beta-lactam antibiotics (cefazolin (CEZ), cefmetazole (CMZ), cloxacillin (MCIPC) and methicillin (DMPPC) against these MRSA were evaluated. Among these 6 AGs, NTL was the most potent, and its MIC50 and MIC80 were 1.56 and 3.13 micrograms/ml, respectively. Antibacterial activities of GM, SISO, DKB and TOB were weak, and MIC50's of GM and DKB were both 100 micrograms/ml, while those of SISO and TOB were 50 and greater than 100 micrograms/ml, respectively. Frequency of highly resistant specimens to AMK was rather low and its MIC50 and MIC80 were 12.5 and 25 micrograms/ml, respectively. As for antibacterial activities of the above 4 beta-lactam antibiotics, the MIC50 and MIC80 of CMZ were 6.25 and 12.5 micrograms/ml, respectively, and therefore, its antibacterial activity to MRSA is relatively good. However, MIC50's of CEZ, MCIPC and DMPPC were all greater than 100 micrograms/ml, showing poor antibacterial activities. Recently, MRSA became a problem in various fields of clinical practice, and a number of literatures reporting refractory infections caused by MRSA have been published. Since MRSA is featured as multiply resistant bacteria, it is known that MRSA is resistant to the majority of existing antibiotics (penicillins, cephems, macrolides, AGs, etc.). In 1985, we reported results of our study concerning the antibacterial activities of a number of CEPs and some of AGs against multiply resistant S. aureus including MRSA.(ABSTRACT TRUNCATED AT 250 WORDS)

Amikacin↗

Profiles of the female-specific serum protein in the Japanese river lamprey, Lampetra japonica (Martens), and the sand lamprey, Lampetra reissneri (Dybowski), in relation to sexual maturation.

The occurrence of female-specific serum protein (FSSP) was examined in the anadromous lamprey, Lampetra japonica, and a freshwater lamprey, Lampetra reissneri, by an immunodiffusion technique using antiserum raised against the serum of sexually mature female lamprey. A considerable amount of FSSP was consistently detected in the blood of vitellogenic, but not in that of nonvitellogenic, females of both species of lampreys. The relative amount of the FSSP tended to become larger in female lampreys at the spawning period. The FSSP may correspond to the yolk precursor protein which is incorporated into ovarian oocytes during the period of exogenous vitellogenesis in the lampreys.

Aging↗

[A clinical bacteriological efficacy study on a fosfomycin otic solution].

Fosfomycin (FOM) otic solution was administered to 587 patients with suppurative otitis media infections including 190 patients in the dose-establishment test, 126 patients in the open clinical trial and 271 patients in the double blind test. Various bacteria were detected in the 549 cases in which bacteriological investigation was possible. Main bacteria detected from the above cases were S. aureus (261 strains, 47.5%), P. aeruginosa (93 strains, 16.9%), coagulase negative Staphylococci (CNS) (89 strains, 16.2%), Providencia spp. (35 strains, 6.4%) and Proteus spp. (28 strains, 5.1%). Twenty-seven strains of anaerobic bacteria (4.9%) were also detected. The MIC of FOM, and the reference drug, chloramphenicol (CP), fradiomycin (FRM), cefmenoxime (CMX) and cephalexin (CEX), were determined up to a concentration of 800 micrograms/ml with inoculum sizes of 10(6) and 10(8) CFU/ml. About 30% of S. aureus was multi-drug resistant, including methicillin and cephems, but FOM showed excellent antibacterial activity against it. The FOM had superior antibacterial activity against P. aeruginosa to CP, FRM and CMX, and was also active against other bacteria. The antibacterial activity of FOM was inferior to other drugs against CNS, Enterobacter spp., P. putida and P. cepacia. The detection rate of these bacteria, however, was low and since their role as causative organisms is not well defined, the inferior activity of FOM has no effect on the bacteriological evaluation of FOM. Since the concentration in the tympanic cavity about 1 hour after the administration of 3% FOM solution was estimated to be 2,000 to 3,000 micrograms/ml, it could be presumed that bacteria inhibited by 800 micrograms/ml of FOM at an inoculum size of 10(8) CFU/ml would be eradicable. The low ototoxicity of FOM is likely due to its characteristic as an inhibitor of bacterial cell wall synthesis. From these results, 3% FOM otic solution may be considered as a remarkably useful topical preparation for the treatment of suppurative otitis media.

Administration, Topical↗

[In vitro susceptibilities of BRL 25000 (clavulanic acid-amoxicillin) against causative organisms in the field of obstetrics and gynecology].

The in vitro susceptibilities of various causative organisms recently isolated from patients with genital infections to BRL 25000 (a formulation with 2 parts of amoxicillin and 1 part of potassium clavulanate), amoxicillin (AMPC), cefaclor (CCL), cephalexin (CEX), cefadroxil (CDX) and cefroxadine (CXD) were determined. beta-Lactamase-producing strains were detected by the nitrocefin disc method. Frequencies of isolation of beta-lactamase producing strains of E. coli, K. pneumoniae and B. fragilis were 36%, 96% and 100%, respectively. The activity of BRL 25000 against S. agalactiae and anaerobic GPC (anaerobic Streptococci, Peptostreptococcus spp.) was slightly less than that of AMPC but was 2- to 4-fold higher than CCL and 8- to 16-fold higher than CEX, CDX and CXD. Against E. coli and K. pneumoniae, the activity of BRL 25000 was superior to that of AMPC and approximately equal to CEX, CDX and CXD but 2-fold less than CCL. Against the B. fragilis group, BRL 25000 was much more active than AMPC or any of the cephalosporins tested, clearly demonstrating the beta-lactamase inhibitory properties of the clavulanic acid in BRL 25000. At inocula of 10(6) CFU/ml, MIC values of BRL 25000 were 12.5-50 micrograms/ml against some strains of E. coli, K. pneumoniae and B. fragilis. A mechanism of resistance other than beta-lactamase production is obviously prevalent in these strains. It is speculated that the resistance may be due to a low affinity of the drug to target proteins. Mixed infections of B. fragilis and E. coli or K. pneumoniae are commonly found in the obstetric and gynecological patients. BRL 25000 shows activity against these strains and also against both aerobic and anaerobic GPC. Therefore, BRL 25000 is considered useful for the treatment of genital infections.

Amoxicillin↗

[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.

Ampicillin↗

[Study of concentrations of clindamycin phosphate in bone marrow blood and tissue].

Clindamycin phosphate (CLDM) was administered to 33 surgical cases in orthopedics to treat or prevent infection (600 mg in 15 cases and 1,200 mg in 18 cases by intravenous drip infusion over 60 minutes) and the concentrations of CLDM in the bone marrow blood and tissue of the operative field as well as in venous blood were determined with the cup plate method of bioassay by collecting specimens immediately after completion of infusion or 30 or 60 minutes later. The concentration of CLDM in bone marrow blood averaged 104.3 approximately 105.5% of the corresponding concentration in venous blood in the cases receiving 600 mg and 101.3% in those receiving 1,200 mg. The concentration of CLDM in bone marrow tissue averaged 154.0 approximately 163.7% of the corresponding concentration in venous blood in the group receiving 600 mg but 78.8 approximately 86.2% in the group receiving 1,200 mg. This difference between the 2 groups was considered to reflect largely the difference in specimens collected. Thus, the concentration of CLDM in bone marrow tissue was interpreted as the amount of drug penetrating and remaining in bone marrow tissue and its adjacent area. The MIC75 of CLDM for clinical isolates were 0.20 micrograms/ml for S. aureus, 0.78 micrograms/ml for B. fragilis and 0.20 micrograms/ml for Peptostreptococcus spp. The concentrations of CLDM attained in bone marrow blood and tissue and its adjacent area after administration of 600 mg or 1,200 mg were thus sufficient to eliminate these organisms. The above results indicate that CLDM is a useful antibiotic for treatment and prevention of infection in orthopedics.

Adolescent↗