Biomedical subjects

S Fukayama

Publications and source records attributed to S Fukayama.

At least 55 records · Page 3Linked to original sources

PubMed1994

[Antibiotic efficacies of combined uses of arbekacin and various antibiotics against methicillin-resistant Staphylococcus aureus].

Efficacies of combined uses of arbekacin(ABK) with other antibiotics against between 57 and 76 clinically isolated methicillin-resistant Staphylococcus aureus(MRSA) were examined. Other antibiotics tested were fosfomycin(FOM), 5 cephems(CEPs), 2 penicillins(PCs) and imipenem. Percentages of strains that grew at various combination of serially diluted drugs in a microdilution method were scored, and for each pair of drugs > or = MIC50 or > or = MIC90 was determined. FIC-indices were calculated at > or = MIC50. Bacterial growth was inhibited by low concentrations of ABK dose-dependently, while most of the strains tested were resistant to 9 other drugs. FIC-indices with ABK were lowest when used together with ampicillin (ABPC) (0.516) followed by combinations with cefotiam (CTM) and cefuzonam (CZON) (each, 0.53), and FOM (0.625). When combined with 0.5 microgram/ml of ABK, 0.5 microgram/ml of ABPC inhibited more than 50% of MRSA strains. CTM or CZON in combination with the same amount of ABK to 2 micrograms/ml inhibited more than 50% of MRSA. Thus ABPC was found to be the most efficient in combined use with ABK to inhibit clinical MRSA strains.

Aminoglycosides↗

PubMed1994

[Antimicrobial activities of cefteram against recently clinically detected and isolated strains from patients with dental infections].

To investigate the antibiotic activity of cefteram (CFTM), the minimum inhibitory concentrations (MICs) of CFTM and of the control drugs were determined against clinically isolated strains received from November 1991 to April 1993 from 19 dental facilities throughout the country, as well as against clinically isolated strains from samples obtained at this center from patients with dental infectious diseases, and the following results were obtained. 1. 430 strains were detected in 198 cases but identified strains amounted to 425. They are comprised of 204 strains of oral streptococci (48.0%), 81 strains of Peptostreptococcus spp. (19.1%), 10 strains of Bacteroides spp. (2.4%), 23 strains of Prevotella spp. (5.4%), and 9 strains of Porphyromonas spp. (2.1%). The ratios of Gram-positive bacteria v.s. Gram-negative bacteria were 78.4% and 21.6%, respectively, and the Gram-positive bacteria were isolated at higher frequency than Gram-negative bacteria. 2. The MIC90's of CFTM against oral streptococci and Peptostreptococcus spp. were 0.10 microgram/ml and 0.05 microgram/ml, and year to year increases of incidences of resistance against CFTM were not observed. Some strains, however, appeared to have obtained resistance to CFTM. 3. Among Bacteroides spp., Prevotella spp., Porphyromonas spp. which used to belong to genus Bacteroides, there were some strains resistant to CFTM. As a whole, however, no year to year increases in the incidence of CFTM resistance among these strains also. 4. Two strains of 6 Staphylococcus aureus subsp. aureus were methicillin-resistant. 5. The above observations indicate that CFTM still shows strong antimicrobial activity against clinically isolated strains that may be involved in dental infections.

Ampicillin↗

PubMed1994

[Antibiotic activities of cefpirome against fresh clinical isolates resistant to multiple drugs].

Using multiple drug-resistant clinical isolates isolated since September 1992, minimum inhibitory concentrations (MICs) of cefpirome (CPR) were determined. Several control drugs were also used, and these MIC-determinations were made to determine the antibiotic activity of CPR. The obtained results are summarized as follows: 1. Antibiotic activities of CPR against methicillin-resistant Staphylococcus spp., Enterococcus faecalis, and benzylpenicillin-insensitive or resistant Streptococcus pneumoniae showed that expanded antibacterial spectrum of CPR and its enhanced antibiotic action against Gram-positive bacteria. We suggest that among the existing fourth-generation cephem antibiotics, CPR is "characteristically strong against Gram-positive bacteria". 2. Strong antibiotic activities of CPR were recognized against bacteria of family Enterobacteriaceae that were resistant to the third-generation cephems. The strong antibiotic activities appeared to be due to CPR's stability and decreased affinity for beta-lactamase. 3. Antibacterial spectrum of CPR was expanded against non-glucose fermented Gram-negative bacilli including Pseudomonas aeruginosa. It appears that this expansion of antibacterial spectrum is due to CPR's affinities for a wide range of penicillin-binding proteins as well as its improved permeability into tissues.

Cephalosporins↗

PubMed1994

[beta-lactamase activity in sputum of patients with community-acquired lower respiratory tract infections].

beta-Lactamase production and activities in sputa of patients with community-acquired lower respiratory tract infections (LRTI) were determined and following results were obtained: 1) Suspected causative organisms frequently isolated were H. influenzae and Streptococcus pneumoniae. Similar results were previously reported. 2) Various beta-lactamase producing indigenous bacteria were detected. In many cases these indigenous beta-lactamase producing strains were isolated even when suspected causative bacteria were not beta-lactamase producers. 3) beta-Lactamase activities were detected from 61.5% of the sputa tested. Remaining activities of antibiotics added to the sputa were highly correlated with detection of beta-lactamases produced by suspectedly causative and indigenous strains and with presence of beta-lactamase activities in the sputa. Sulbactam/cefoperazone was stable in sputa than other antibiotics tested. 4) We concluded that the beta-lactamase produced by indigenous strains can be one of the factors of indirect pathogenicity in the community-acquired LRTI.

Cefoperazone↗

PubMed1994

[Antimicrobial activities of cefuroxime against recent clinical isolates].

Antimicrobial activity of cefuroxime axetil (CXM-AX) was compared with those of other cephem antibiotics against clinically isolated strains obtained mainly from outpatients of our center in a period from January to September of 1990 and 1993. Minimum inhibitory concentrations were determined and the following results were obtained. 1. The results suggested that, compared with reports of studies conducted with clinical isolates in early 1980's, MIC80 of CXM were equal to or lower against Staphylococcus spp., Streptococcus pyogenes, Escherichia coli, Klebsiella spp., Proteus mirabilis, Haemophilus influenzae, Moraxella subgenus Branhamella catarrhalis, Neisseria gonorrhoeae, Peptostreptococcus spp., and Propionibacterium acnes, except for Streptococcus pneumoniae, MIC80 which was slightly higher. 2. MIC90 of comparator drugs reflected those of new resistant organisms recently appeared, such as benzylpenicillin (PCG)-insensitive S. pneumoniae (PISP), cephem-resistant E. coli and Klebsiella spp., new quinolone-resistant H. influenzae and N. gonorrhoeae. Methicillin-resistant Staphylococcus aureus (MRSA) was detected also from specimens of community acquired infections. From the nature of MRSA detected in those situations MRSA appeared to present a continuing problem. 3. MIC90 against strains obtained from patients with community acquired infections was a good index of increases of multidrug-resistant organisms in the past. Therefore, the determination of MIC90 is important in examining changes with time of sensitivities or resistances of clinically isolated strains to antimicrobial drugs. 4. Antimicrobial activities of CXM against recent clinical isolates showed the existence of problems as mentioned above. However, MIC of CXM as well as those of comparator drugs indicated that antimicrobial activities of CXM against Staphylococcus spp., Streptococcus spp., H. influenzae appeared to be relatively strong, and it is concluded that cefuroxime axetil still is one of the clinically useful oral antimicrobial drugs in the 1990's.

Bacteria↗

PubMed1993

Role of protein kinase A in the regulation of cytosolic free calcium in human osteoblast-like SaOS-2 cells.

We have used wild-type and adenosine 3',5'-cyclic monophosphate (cAMP)-resistant mutant osteoblast-like SaOS-2 cells to investigate the role of protein kinase A (PKA) in the regulation of cytosolic free Ca2+ concentration ([Ca2+]i). Basal levels of [Ca2+]i were the same in wild-type (127 +/- 6.1 nM) and transfected (117 +/- 6.8 nM) SaOS-2 cells, although 45Ca2+ efflux was slower in the transfected cells. In wild-type cells, thapsigargin (TG, > or = 200 nM), an inhibitor of the Ca(2+)-ATPase activity of the endoplasmic reticulum, acutely increased [Ca2+]i (by up to 2-fold), which then returned promptly to basal [Ca2+]i. In cAMP-resistant cells, TG elicited a significantly greater acute rise in [Ca2+]i, which then decayed to an elevated plateau level. In mutant cells, high concentrations of dibutyryladenosine 3',5'-cyclic monophosphate, which overcome the PKA blockade, restored the changes in [Ca2+]i to the wild-type pattern. In cAMP-resistant, TG-blocked cells, ionomycin (or alpha-thrombin) induced a further elevation in [Ca2+]i, which then declined rapidly to the original basal level. We conclude that basal PKA activity is involved actively in regulation of [Ca2+]i in SaOS-2 cells by promoting Ca2+ efflux from the cell and, possibly, by inhibiting Ca2+ release from or stimulating net Ca2+ sequestration into the ER. We have also obtained evidence for an alternate Ca(2+)-triggered Ca2+ reuptake mechanism in SaOS-2 cells that is not dependent on either Ca(2+)-ATPase or PKA.

Bucladesine↗

PubMed1993

[Antibacterial activities of cefmenoxime against recent clinical isolates from patients of otitis media and otitis externa].

Bacteria clinically isolated from patients of otitis media and otitis externa were collected from various medical facilities across Japan during years 1988, 1990 and 1992, and minimum inhibitory concentrations (MICs) of cefmenoxime and of reference drugs were determined against these strains. A comparative analyses of the obtained results revealed some trends described below. 1. Methicillin-resistant Staphylococcus aureus (MRSA), multiple drug resistant Coagulase-negative staphylococci (CNS) and multiple drug resistant Proteus spp. showed a year to year trend toward a steady increasing. Relative frequencies of occurrence of MRSA in these years, however, remained comparable to that of early 1980's. 2. A year to year trend toward increasing was also found for resistant or insensitive Streptococcus pneumoniae to penicillins and cephems. 3. Multiple drug-resistant Pseudomonas aeruginosa strains were also detected but they showed no trend toward increasing.

Bacteria↗

PubMed1993

[Antimicrobial activity of cefodizime against fresh clinical isolates].

In order evaluate antimicrobial activities of cefodizime (CDZM), minimum inhibitory concentrations (MIC's) of CDZM and other control drugs were determined against various clinical isolates, that were sent to our center from nation-wide medical institutions or were isolated and identified in our laboratory from various specimens of infected patients. The followings are a summary of the results: 1. Bacterial species with no or few strains resistant to cephems including CDZM included Streptococcus pyogenes, Haemophilus influenzae, Citrobacter diversus, most of Klebsiella pneumoniae and Proteus mirabilis. Some strains of Klebsiella oxytoca were resistant to cephems increases in beta-lactams resistant Streptococcus pneumoniae and cephem resistant Escherichia coli seemed likely. Among Citrobacter freundii, Enterobacter spp., Serratia marcescens, Proteus vulgaris, Morganella morganii and Providencia spp. belonging to a category of so-called "mildly toxic bacteria", high portions of the strains examined were resistant to cephems including CDZM and these strains were also resistant to new quinolones, thus they showed multiple drug resistance. 2. MIC90's of CDZM against Streptococcus spp., H. infleunzae, Moraxella subgenus Branhamella catarrhalis, E. coli, Klebsiella spp. and P. mirabilis, frequently found in daily treatment of infections, were less than < or = 0.025 to 1.56 micrograms/ml. This indicates that CDZM would be expected to have enough antibiotic activity in infections caused by above mentioned bacteria. However, cautions are needed in the treatment of infections by beta-lactam resistant S. pneumoniae, cephem resistant E. coli and cephem resistant K. oxytoca with CDZM. 3. Among the above mentioned "mildly toxic bacteria", many multiple drug resistant strains exist. Therefore, we evaluated an usefulness of concomitant use of CDZM with aminoglycosides in the treatment of infections by these bacteria, using other reports which indicates the usefulness in vitro and in vivo. 4. Antibacterial activities of CDZM we observed in this study seem to indicate that CDZM concentrations in infected areas are maintained at above MIC levels for relatively long periods of time.

Bacteria↗

PubMed1993

[Antimicrobial activities of polymyxin B against clinically isolated microbial strains. Results of MIC determination including high concentrations].

Minimum inhibitory concentrations (MICs) were determined for polymyxin B (PL-B), gentamicin, ofloxacin and norfloxacin against clinically isolated microbial strains collected since November 1992, and the following conclusions were obtained: 1. Judging from the MIC distribution of PL-B against the studied strains including multi-drug resistant organisms of major strains of family Enterobacteriaceae, such as Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., and Pseudomonas aeruginosa, it appeared that no PL-B resistant strains were detected among those Gram-negative organisms within the antimicrobial spectrum of PL-B. 2. MICs of PL-B against most strains including methicillin resistant Staphylococcus aureus and coagulase-negative staphylococci were distributed between 100 and 800 micrograms/ml. These results supported reports of other investigators that the eradication of Staphylococcus spp. including MRSA (methicillin-resistant S. aureus) was possible by the use of PL-B at 1 mg/ml. 3. MIC distribution of PL-B against organisms of the Bacteroides fragilis group was almost the same as the results described above.

Bacteria↗

PubMed1993

[Antimicrobial activities of sultamicillin against clinical isolates obtained from outpatients].

Minimum inhibitory concentrations (MICs) were determined for sultamicillin (SBTPC), and for other major oral beta-lactam agents against clinically isolated strains collected from outpatients during a period from August, 1992 to February, 1993, and the following conclusions were obtained. 1. The ratio of penicillinase (PCase)-producing strains of Staphylococcus aureus was 96.0% and that of methicillin-resistant S. aureus (MRSA) was 12.0%. MIC90 of SBTPC against S. aureus including MRSA was 6.25 micrograms/ml. No increasing tendency was observed for S. aureus resistant to SBTPC. 2. No resistant strains were found among Streptococcus pyogenes and Enterococcus faecalis against penicillins (PCs) including SBTPC. But PCs and cephems (CEPs) insensitive or resistant Streptococcus pneumoniae were observed in 22.0% among all the strains of S. pneumoniae. 3. 100% of the tested both strains of Escherichia coli and Proteus mirabilis were beta-lactamase producers. 12.0% of the tested strains of Haemophilus influenzae and 16.0% of the strains of Neisseria gonorrhoeae were also beta-lactamase producers. SBTPC showed strong antimicrobial activity against most of these beta-lactamase producing strains. However, in our study of beta-lactamase productivity using plural substrates and test methods, it appeared that a part of strains of E. coli might produce beta-lactamase of "Extended broad-spectrum". MICs of SBTPC and CEPs against those strains were distributed rather in a high range. 4. The results of the study suggested that the resistant strains of S. pneumoniae against PCs and CEPs might be increasing year by year. Some of strains of E. coli, resistance against the 2 agents were observed. It is important to keep observing changes in resistance of such organisms in the future. 5. The antimicrobial activities of SBTPC against clinically isolated strains in this study indicated potential problems such as those mentioned above. It is, however, also confirmed that SBTPC shows still strong antimicrobial activities against most of beta-lactamase producing strains found in daily medical examinations. Taking into consideration of the strong activities of SBTPC against so-called indirect pathogenicity caused by beta-lactamase producing indigenous bacteria reported lately, SBTPC may be a useful antibiotic for community acquired infections in the 1990's.

Ampicillin↗

PubMed1993

[Antimicrobial activities of arbekacin against methicillin-resistant Staphylococcus aureus isolated from patients of a pediatrics ward].

Aiming at measuring the antimicrobial activities of arbekacin (ABK) against the strains of methicillin-resistant Staphylococcus aureus (MRSA), isolated from pediatrics patients in 1992, the minimum inhibitory concentration (MIC) of 8 antibiotics including ABK was determined and the coagulase types of those strains were also examined. The obtained results are summarized as follows. 1. Among coagulase types of a total of 78 strains, Type II, Type IV and Type VII were 84.6%, 12.8% and 2.6%, respectively. No clear difference in coagulase types were observed among their origins of isolation. 2. MIC90 of ABK against 42 strains isolated from the air passage of suspected pneumoniae patients and 36 strains isolated from the blood of suspected septicemia patients were 1.56 micrograms/ml and 3.13 micrograms/ml, respectively, and MIC90 of ABK against the 78 strains was 1.56 micrograms/ml, which was equal to that of vancomycin (VCM). 3. Most of these strains exhibited resistance against multiple antibiotic agents including cefmetazole (CMZ), imipenem (IPM), fosfomycin (FOM) and minocycline. Strains isolated from the blood were mostly resistant to multiple agents, and most of them were especially highly resistant to CMZ and IPM. ABK, however, showed potent antimicrobial activities even to those strains. These results were similar to the results obtained several years ago. 4. Considering the fact that ABK demonstrates not only potent antimicrobial activities against MRSAs isolated from the pediatric patients, but also shows remarkable clinical effects with concomitant use with beta-lactams or FOM, the prospect of ABK use in MRSA infectious diseases of children is excellent.

Aminoglycosides↗

PubMed1993

[The antimicrobial activity of cefteram against recently clinically detected and isolated strains].

In order to examine antibiotic activities of cefteram (CFTM), its minimum inhibitory concentrations (MIC's) and those of other cephem drugs were determined against clinically isolated strains received from July 1990 to June 1991 and from July 1992 to February 1993 from medical facilities throughout the country and against clinically isolated strains detected in our laboratory in samples from patients with various infectious diseases. The obtained results are summarized below. 1. No CFTM-resistant strains were found among beta-streptococci, Klebsiella spp., Proteus mirabilis, Haemophilus influenzae, and Neisseria gonorrhoeae or even when found, they were present in extremely low proportions. 2. It appeared that Streptococcus pneumoniae insensitive or resistant to beta-lactams, as well as cephems-resistant strains of Escherichia coli were increasing. The former included benzylpenicillin (PCG)-insensitive S. pneumoniae (PISP) of PCG-resistant S. pneumoniae (PRSP), and the presence of the latter suggests the possibility of the existence of "Extended broad-spectrum beta-lactamase" producing strains. The MIC's of beta-lactams against the above PISP or PRSP, and against cephems-resistant E. coli tended to be high, but those of CFTM were relatively low (in most cases). 3. Proportions of strains resistant to cephems, including CFTM among Citrobacter spp., Enterobacter spp., Serratia marcescens, Proteus vulgaris, Morganella morganii, and Providencia rettgeri were high, and in addition, the existence of these cephem resistant species suggests an increase in multiple drug resistant strains that show resistance to new quinolone drugs. 4. As mentioned above, CFTM is by no means a perfect drug or utility drug and its antimicrobial activities do not cover some recent isolates with multiple drug resistance. Except problems encountered with so-called "attenuated" strains of bacteria, increases in resistance can only be observed at a level of MIC90's, and as far as MIC80's are concerned, CFTM still is as active as before and may be used in the treatment of most infections we encounter in normal medical practices.

Bacteria↗

PubMed1993

[Bacteriological evaluation of combined effects of vancomycin and beta-lactams. I. Results against methicillin-resistant Staphylococcus aureus].

We previously reported a part of the results we obtained regarding antibacteriological synergism between beta-lactams and vancomycin (VCM) against methicillin-resistant Staphylococcus aureus (MRSA). This paper reports an additional assessment we made subsequently to the previous report regarding antibacterial effects of different beta-lactams and VCM concurrently used against MRSA. Assessed in this study were bacteriological synergistic actions between flomoxef (FMOX) and VCM, latamoxef (LMOX) and VCM, cefpirome (CPR) and VCM and imipenem (IPM) and VCM against MRSA. 1. Synergistic enhancements of therapeutic activities were observed against MRSA with FMOX +VCM, CPR + VCM and IPM + VCM, but the activity of LMOX + VCM was low. 2. Concentration dependencies of actions of these antibiotic agents against MRSA were strong for beta-lactams, but weak for VCM. These observations were opposite of the results for beta-lactams and aminoglycosides, or beta-lactams and tetracyclines against MRSA we reported previously. 3. It appeared that strong synergistic antibacterial effects were obtained with FMOX or CPR concentrations between 8 and 32 micrograms/ml when used with VCM, and IPM concentrations between 4 and 16 micrograms/ml when used with VCM, hence, in the therapy using these combinations, concentrations and dose intervals of beta-lactams employed should be carefully considered. 4. When these antibiotics are used together in in vitro experiments, values of MIC and FIC-index may be different depending upon experimental systems used.

Anti-Bacterial Agents↗

PubMed1993

[Bacteriological evaluation of combined effects of vancomycin and beta-lactams. II. Results against gram-negative rods].

Evaluations were made for antibacterial activities of combination uses of flomoxef (FMOX) + vancomycin (VCM) against clinically isolated bacteria of family Enterobacteriaceae, and latamoxef (LMOX) + VCM, cefpirome (CPR) + VCM, and imipenem (IPM) + VCM against also clinically isolated Pseudomonas aeruginosa. The obtained results are summarized as follows. 1. FMOX and VCM appeared to act independently against Enterobacteriaceae without showing synergism or antagonism. 2. Regarding antibacterial effects of LMOX + VCM, or CPR + VCM against P. aeruginosa strains, MIC values under the combined uses were approximately 1 dilution (2 folds) higher than LMOX or CPR used alone, but we did not consider that these results meant the presence of antagonism between the beta-lactams and VCM. 3. Experimental results suggested that an antagonistic relationship was present between IPM and VCM against P. aeruginosa. The degree of the antagonism was dependent on VCM concentrations. In other words, when VCM is present at a concentration between 4 and 128 micrograms/ml, MIC values for IPM increased 2 to 4 dilutions (4 to 16 folds), whereas in the presence of 1 to 2 micrograms/ml VCM, MIC values for IPM were close to those of IPM alone. Further, some of this tendency was observed for FMOX against bacteria of family Enterobacteriaceae in the presence of VCM. 4. These results suggest that the dose level of VCM should be considered based on a low range when a combination therapy is considered between beta-lactams and VCM in the treatment of infections with MRSA alone or with Gram-negative rods with MRSA.

Anti-Bacterial Agents↗

PubMed1993

[Antibacterial activities of ofloxacin against recent clinical isolates from patients with ocular infections].

In order to study antibacterial activities of ofloxacin (OFLX), minimum inhibitory concentrations (MICs) of OFLX were determined against clinical isolates obtained from ophthalmic institutes all over the country and those isolated and identified from patients with various ocular infections during three years from September 1989 until August 1992, and the results were compared with those of the control drugs. The following results were obtained. 1. Compared with the reports by others presented from 1984 through 1986, increases were observed for strains with moderate or low susceptibilities to OFLX such as Staphylococcus spp., Corynebacterium spp., Serratia spp., and glucose-nonfermentative Gram-negative rods ((G) NF-GNR). 2. Although incidence of resistance to OFLX increased among the above strains, remarkably low frequencies was observed for the occurrence of highly resistant strains to OFLX with MIC value > 100 micrograms/ml. 3. The antibacterial spectrum of OFLX covered (G)NF-GNR, and the activity of OFLX was superior to those of aminoglycosides, penicillins and cephems used as the control drugs. 4. Low incidence of highly resistant strains to OFLX and its broad antibacterial spectrum suggested the usefulness of a 0.3% OFLX ophthalmic solution in achieving concentrations exceeding MIC for a prolonged period of time.

Drug Resistance, Microbial↗

PubMed1993

[Bacteriological evaluations of combination effects with cefotiam and other antimicrobial agents against methicillin-resistant Staphylococcus aureus. I. Synergistic actions of cefotiam with imipenem and vancomycin].

We assessed the bacteriological efficacies of cefotiam (CTM) plus imipenem (IPM) and CTM plus vancomycin (VCM) therapies against methicillin-resistant Staphylococcus aureus (MRSA) in an in vitro system. The results are summarized as follows. 1. It appeared that the bacteriological efficacies of CTM+IPM therapy against MRSA strains were different against different target MRSA strains. In other words, the FIC indices of CTM+IPM were distributed in a wide range of < or = 0.5- > 2.0. The strains showing MIC levels of < or = 8 micrograms/ml in IPM concentrations showed a strong correlation with FIC index values of < or = 0.5, and the strains showing the MIC level of > or = 128 micrograms/ml in IPM concentration showed a strong correlation with FIC index values of > 2.0. Hence, the strains showing FIC indices < or = 0.5 were considered to be newborn strains with penicillin-binding protein 2' (PBP-2'), those showing FIC indices > 0.5- < or = 2.0 were considered to be strains with increasing production in PBP-2', and those showing FIC indices > 2.0 were considered to be strains with increasing productions in both PBP-2' and PBP-m2. In strains with FIC indices higher than 2.0, the 2 drugs may possibly share the action mechanism and the activity center thus they compete with each other.(ABSTRACT TRUNCATED AT 250 WORDS)

Cefotiam↗

PubMed1993

[Bacteriological evaluations of combination effects with cefotiam and other antimicrobial agents against methicillin-resistant Staphylococcus aureus. II. Synergistic actions of cefotiam with arbekacin and minocycline].

We assessed the bacteriological efficacies of cefotiam (CTM) plus arbekacin (ABK) and CTM plus minocycline (MINO) therapies against methicillin-resistant Staphylococcus aureus (MRSA) in an in vitro system. The results are summarized as follows. 1. Both of CTM+ABK and CTM+MINO demonstrated almost perfect antibacterial activities against MRSA strains at ABK and MINO concentrations of MIC levels as clinically expected plasma ABK or MINO levels, and also showed antibacterial activities at ABK or MINO concentrations of sub-MIC levels. But no results suggesting antagonism were obtained. 2. The potent antibacterial effect of CTM+ABK or CTM+MINO against MRSA strains was considered to be the result of damage to the cellular membrane of target strains by ABK or MINO with ABK or MINO concentrations at MIC or sub-MIC levels and by the subsequent antibiotic effect of CTM. 3. A combination of drugs which are different from each other in mechanisms of action and points of action is likely to show a consistent antibacterial effect, but a combination of drugs which are competitive to each other because they share mechanism and point of action possibly cause antagonism.

Aminoglycosides↗

PubMed1993

[Antimicrobial activities of cefminox against recent clinical isolates].

Against main clinical isolates at our center in 1990 to 1992, the minimum inhibitory concentrations (MICs) of cefminox (CMNX) and some other comparable cephems were determined. The results are summarized as follows. 1. As to the strains resistant to cephems including CMNX, annual increases were observed for Streptococcus pneumoniae among Gram-positive bacteria and Proteus vulgaris among Gram-negative bacteria. Moreover, cephem-resistant strains of Escherichia coli were constantly isolated, and there were signs indicating that cephem-resistant strains would increase among strains of Klebsiella pneumoniae. 2. The annual increases in cephem-resistant strains of S. pneumoniae and P. vulgaris may respectively reflect the recent increases in the incidence of benzylpenicillin (PCG)-insensitive strains of S. pneumoniae (PISP) and multi-drug resistant strains including oxime type cephems and new quinolones introduced into clinical use in the latter half of the 1980s. 3. Concerning antimicrobial activities of CMNX against recent clinical isolates, the same problems as described above will remain. However, these tendencies have been observed only with regard to MIC90. No remarkable changes have been noted for MIC50 or MIC80 at this time.

Cephamycins↗