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1.
The susceptibility of 1,476 US and European strains of anaerobic gram-negative bacilli to amoxicillin, amoxicillin/clavulanate, ticarcillin, ticarcillin/clavulanate, cefoxitin, imipenem and metronidazole was determined. All of theBacteroides fragilis group and 51 % of the non-Bacteroides fragilis group were -lactamase positive. Amongst the non-Bacteroides fragilis group, -lactamase positivity rates were higher for US strains (58 %) than for European strains (39 %). All strains were susceptible to imipenem and metronidazole. MIC90s of amoxicillin and ticarcillin for all -lactamase negative strains were 0.5 and 2 µg/ml, respectively. The addition of clavulanate reduced the MIC90s of amoxicillin ( 256 µg/ml) and ticarcillin ( 64 µg/ml) to 16 and 8 µg/ml, respectively, for theBacteroides fragilis group, and to 4 µg/ml for both agents for the non-Bacteroides fragilis -lactamase producing group. Twenty-nine cefoxitin-resistant strains were found, mainly in theBacteroides fragilis group, while 95 -lactamase producing strains (predominantlyBacteroides fragilis group and fusobacteria) did not show synergy between -lactams and clavulanate. Of the newer agents tested, meropenem and piperacillin-tazobactam were the most active (100 % of strains susceptible), followed by amoxicillin-BRL 42715 (99 % of strains susceptible); 94 to 98 % of the strains were susceptible to cefoperazone-sulbactam, tosufloxacin, tempafloxacin and clindamycin. Only 73 % of the strains were susceptible to cefotetan, compared to 91 % to cefoxitin; 88 % of the strains were susceptible to trospectomycin. Overall, all of the -lactam/-lactamase inhibitor combinations, imipenem, meropenem, cefoxitin, tosufloxacin, temafloxacin and clindamycin had good activity against -lactamase producing strains, while all agents tested had good activity against -lactamase negative strains.  相似文献   

2.
The activity of biapenem was compared with that of imipenem and cefotaxime against 108 strains of -lactamase producingEnterobacteriaceae. Biapenem and imipenem were very active, inhibiting 90 % of the strains at a concentration of 0.5 µg/ml. Both carbapenems were very active against plasmidic -lactamase producers, with MIC90s below 1 µg/ml. However, the MIC90 of biapenem for cephalosporinase producers was 1 µg/ml. Against strains producing extended-spectrum -lactamases, biapenem exhibited better activity against TEM-type producers (MIC90 0.25 µg/ml) than against SHV-type producers (MIC90 0.5 µg/ml). Overall, the in vitro antibacterial activity of biapenem is similar to that of imipenem.  相似文献   

3.
To confirm preliminary interpretive breakpoints for prototype 5 µg levofloxacin disks, 490 strains were tested in vitro using commercially manufactured disks. For in vitro susceptibility testing, 5 µg levofloxacin disks can be used with interpretive criteria of 12 mm for resistant (MIC 8.0 µg/ml) and 16 mm for susceptible (MIC 2.0 µg/ml). Proposed quality control limits for tests of levofloxacin are as follows:Escherichia coli ATCC 25922, zones 29–37 mm or MIC 0.008–0.03 µg/ml;Pseudomonas aeruginosa ATCC 27853, zones 19–26 mm or MIC 0.5–2.0 µg/ml;Staphylococcus aureus ATCC 25923, zones 24–31 mm;Staphylococcus aureus ATCC 29213, MIC 0.06–0.25 µg/ml andEnterococcus faecalis ATCC 29212, MIC 0.25–2.0 µg/ml.  相似文献   

4.
Zusammenfassung Seit Juli 1978 wurden 103 Patienten mit inoperablem kleinzelligem Bronchialkarzinom mit der Zytostatikakombination Adriamycin, Cyclophosphamid und Vincristin (ACO) behandelt. Im Stadium limited disease (n=64) erfolgte während des zweiten Chemotherapiekurses eine prophylaktische Schädelbestrahlung, nach dem vierten eine konsolidierende thorakale Bestrahlung. Nach Erreichen einer kompletten Remission erhielten die Patienten prospektiv randomisiert Etoposid oder keine weitere spezifische Therapie. Ein objektives Ansprechen konnte bei 88/100 auswertbaren Patienten erzielt werden. Im Stadium limited disease fanden sich 72%, im Stadium extensive disease nur 33% komplette Remissionen. Im Stadium limited disease betrug die hochgerechnete mediane Überlebenszeit 15,8, im Stadium extensive disease 9,3 Monate (p<0.005). Es leben noch 29 Patienten, 4 rezidivfrei länger als 24 Monate. Patienten mit kompletter Remission hatten eine statistisch signifikant (p<0.001) längere Überlebenszeit als Patienten mit geringerem Ansprechen. Regelmäßig traten gastrointestinale und hämatologische Nebenwirkungen auf, drei Patienten starben während der Induktionsphase an Infektionen. Die kurzzeitige Induktionsbehandlung verbesserte jedoch den Krankheitsverlauf subjektiv und objektiv. Bisher ist kein positiver Effekt der zyklischen Etoposid-Gabe nach ACO festzustellen.Vorliegende Untersuchungen wurden gefördert im Rahmen des Forschungsprogramms Arzneimittelentwicklung und -testung für die Krebstherapie des BMFT  相似文献   

5.
Studies with fosfomycin tromethamine disks containing 200 µg of fosfomycin and 50 µg of glucose-6-phosphate confirmed the following zone diameter criteria for the NCCLS method: 12 mm for resistant (MIC256 µg/ml), 13–15 mm for intermediate (MIC 128 µg/ml) and 16 mm for susceptible (MIC64 µg/ml). Additional studies defined acceptable MIC and zone diameter ranges for the following quality control strains:Escherichia coli ATCC 25922, MIC 0.5 to 4.0 µg/ml, zone diameter 23 to 29 mm;Staphylococcus aureus ATCC 25923, zone diameter 26 to 32 mm;Pseudomonas aeruginosa ATCC 27813, MIC 2.0 to 8.0 µg/ml; andEnterococcus faecalis, ATCC 29212, MIC 16 to 64 µg/ml.  相似文献   

6.
The efficacy of the clinically available -lactam/-lactamase inhibitor combinations (amoxicillin/clavulanic acid (CA), ticarcillin/CA, amoxicillin/sulbactam, and piperacillin/ tazobactam) was evaluated on 300 amoxicillin-resistantEscherichia coli isolates having the main patterns of -lactam resistance. The patterns, which reflect the production of various -lactamase enzymes, were analyzed by a principal component analysis of susceptibility to 11 -lactam antibiotics or -lactam/-lactamase inhibitor combinations. Sixty-two percent of strains were not very susceptible to penicillins, cephalothin, or any -lactam/-lactamase inhibitor combinations except for piperacillin/tazobactam; these strains may represent high-level broad-spectrum -lactamase (so-called penicillinase) production phenotype or inhibitor-resistant TEM-like enzyme production phenotype. Of the strains, 14.7 % were resistant to amoxicillin and ticarcillin compatible with low-level broad-spectrum -lactamase production phenotype; 5.7 % were cefoxitin resistant and were postulated to present a high-level cephalosporinase production phenotype; and 2.6 % were resistant to cephalothin only, attributable to a low-level cephalosporinase production phenotype. Three percent of strains were intermediate or resistant to cefotaxime and may produce an extended-spectrum -lactamase, and the remaining strains (12 %), resistant to all tested antibiotics except for cefotaxime and piperacillin/tazobactam, were hypothesized to produce both broad-spectrum -lactamase plus cephalosporinase. The minimal inhibitory concentration (MIC) for these phenotype patterns indicated that combinations of CA plus amoxicillin or ticarcillin, or sulbactam plus amoxicillin, restored the activity of penicillins against phenotype 1 strains, whereas these combinations remained inactive against the other phenotype strains. Piperacillin plus tazobactam showed the best in vitro effect against the strains of all resistance phenotypes.  相似文献   

7.
Haemophilus influenzae strains with varied ampicillin resistance and beta-lactamase production patterns were tested against three investigational fluorinated quinolones (CI-960, fleroxacin, temafloxacin) using Haemophilus Test Medium (HTM) and National Committee for Clinical Laboratory Standards (NCCLS) methods. The disk diffusion zones and MICs were compared and regression statistics and scattergrams generated. The rank order of the agents according to activity againstHaemophilus influenzae was CI-960 (MIC50 0.002 µg/ml) > temafloxacin (MIC50 0.015 µg/ml) > fleroxacin (MIC50 0.03 µg/ml). The recommended susceptibility interpretive criteria for the 5-µg disks of each drug were: for CI-960 23 mm (MIC correlate 1 µg/ml); for fleroxacin 19 mm (MIC correlate 2 µg/ml); and for temafloxacin 16 mm (MIC correlate 2 µg/ml). All recentHaemophilus influenzae isolates tested were susceptible to these potent fluoroquinolones and no interpretive errors were observed.  相似文献   

8.
The effects of polymorphonuclear neutrophils (PMNs) and/or clavulanic acid on the bactericidal activity of amoxicillin (at human serum achievable concentrations) against a serotype 3 penicillin-susceptibleStreptococcus pneumoniae strain [minimal inhibitory concentration /minimal bactericidal concentration (MIC/MBC) values of penicillin, amoxicillin, and amoxicillin/clavulanic acid (2:1)=0.01/0.01 g/ml] and a serotype 9 penicillin-resistant strain [MIC/MBC of penicillin, amoxicillin, and amoxicillin/clavulanic acid (2:1)=1/2 g/ml] were studied. Against the penicillin-resistant strain, subinhibitory concentrations of amoxicillin reduced the growth rate; this effect was increased by the addition of clavulanic acid. A reduction of the penicillin-resistant initial inocula (3 × 106 cfu/ml) at subinhibitory concentrations was obtained only with amoxicillin plus clavulanic acid and PMNs. At suprainhibitory concentrations, both clavulanic acid and PMNs increased the bactericidal activity of amoxicillin, as evidenced by an increased reduction in the penicillin-resistant initial inocula. The combined effect of these antibiotics and immune defenses may help explain the maintenance of their clinical efficacy in respiratory tract infections, despite the increase in the incidence of penicillin-resistant pneumococci.  相似文献   

9.
The in vitro activity of cefdinir (CI-983; FK-482), a new oral cephalosporin, was compared with that of other antimicrobial agents against clinical isolates of staphylocci, gram-negative bacilli and common respiratory tract pathogens. Cefdinir (MIC90 2.0 µg/ml) was more active than cefixime (MIC90 >64 µg/ml) and equally as active as cefuroxime (MIC90 2.0 µg/ml) against oxacillin-susceptible staphylococci. Cefdinir was active againstHaemophilus influenzae, including -lactamase producers (MIC90 0.5 µg/ml),Moraxella catarrhalis (MIC90 0.12 µg/ml),Streptococcus pneumoniae (MIC90 0.06 µg/ml) andStreptococcus pyogenes (MIC90 0.06 µg/ml). The activity of cefdinir against gram-negative bacilli was variable; organisms with chromosomal cephalosporinases were often resistant.  相似文献   

10.
In vitro studies in five different medical centers documented the susceptibility of 2,440 consecutive isolates of theEnterobacteriaceae against ampicillin-sulbactam disks of different potencies. For determination of MICs, both 2:1 or 1:1 ratios were used as long as the concentrations of sulbactam at the breakpoints remained the same, i.e. MIC 16/8.0 µg/ml or 8.0/8.0 µg/ml for the susceptible category. Disks containing 10 µg of ampicillin and 10 µg of sulbactam are still to be preferred with interpretive criteria of 15 mm for susceptible and 11 mm for resistant (MIC 64/32 µg/ml or 32/32 µg/ml). The reliability of the disk test actually diminished when the amount of sulbactam in the disk was increased.  相似文献   

11.
The aim of the current five-center collaborative study was to reassess the interpretive criteria for cefaclor, loracarbef, cefprozil and cefixime previously adopted or proposed by the National Committee for Clinical Laboratory Standards (NCCLS) for disk diffusion susceptibility tests withHaemophilus influenzae on Haemophilus Test Medium (HTM) agar. MICs and zones of inhibition were determined using NCCLS methods, HTM and two collections of strains ofHaemophilus influenzae. One group of strains consisted of 118 stock organisms taken largely from various recent U.S. antibiotic resistance surveillance studies. The emphasis in this selected group of organisms was on strains that were beta-lactamase negative but ampicillin resistant (BLNAR) by some other mechanism. The second collection of test organisms consisted of 50 recent clinical isolates ofHaemophilus influenzae obtained from each of the five participating study centers. This group was considered representative of the type ofHaemophilus influenzae currently recovered from clinical sources in the USA. Frequency distribution assessment and error-rate bounded analysis of scattergram comparisons of MICs and zone sizes were used to develop the following zone diameters interpretive for disk diffusion susceptibility tests withHaemophilus influenzae on HTM agar: cefaclor, 20 mm (susceptible, S) and 16 mm (resistant, R); loracarbef, 19 mm (S) and 15 mm (R); and cefprozil, >18 mm (S) and <14 mm (R). The respective MIC correlates for all three antimicrobial agents were 8 µg/ml (S) and 32 µg/ml (R). For cefixime, a zone diameter size of 21 mm was recommended to define the susceptible category, with an MIC correlate of 1 µg/ml. Only a susceptible category was defined for cefixime testing. These new interpretive criteria have recently been adopted by the NCCLS.  相似文献   

12.
The in vitro activity of OPC-17116 was compared to that of five similar fluoroquinolones (ciprofloxacin, enoxacin, norfloxacin, ofloxacin and temafloxacin). A total of 700 isolates from recent cases of clinical bacteremia were tested. Fifty additional stock strains with well-characterized resistance mechanisms were also processed. The minimal concentrations inhibiting 90 % of strains (MIC90) ofEnterobacteriaceae species were for OPC-17116 0.015–0.5 µg/ml and for ciprofloxacin 0.015–0.25 µg/ml.Moraxella catarrhalis, Haemophilus influenzae andNeisseria gonorrhoeae were very susceptible to OPC-17116 (MIC90 0.015 µg/ml) thus being fourfold more active than ciprofloxacin. For all -hemolytic streptococci and pneumococci OPC-17116 MICs were 0.5 µg/ml. The most resistant enteric bacilli were among theCitrobacter freundii andProvidencia rettgeri strains (MIC90 0.5 µg/ml).Pseudomonas aeruginosa strains were comparably susceptible to OPC-17116 (MIC90 0.5 µg/ml). Low pH and CO2 incubation had an adverse effect on OPC-17116 MICs, and resistance development was documented among current clinical isolates of staphylococci, pseudomonas and someEnterobacteriaceae.  相似文献   

13.
The inhibitory activity of eight antibiotics and the inhibitory and bactericidal activities of combinations of trimethoprim/sulfamethoxazole (TMP/SMX) plus three fixed concentrations of polymyxin B (0.01 g/ml, 0.1 g/ml and 0.5 g/ml) against 30 multiresistant strains ofStenotrophomonas maltophilia were tested. Polymyxin B at 0.01 g/ml modified the inhibitory activity of TMP/SMX against only 40% of strains. At 0.1 g/ml and 0.5 g/ml, polymyxin B enhanced the inhibitory activity of TMP/SMX activity against all strains. Polymyxin B enhanced the bactericidal activity of TMP/SMX only at concentrations near the minimum inhibitory concentration of polymyxin B alone.  相似文献   

14.
In 210 strains ofEnterobacteriaceae which were isolated in four hospitals and which showed reduced susceptibility to cefotaxime, high synergy was demonstrated between amoxicillin (20µg) + clavulanate (10µg) and cefotaxime (30µg) using a simple double-disk test. Isoelectric focusing on gel and specific iodometric detection using ceftriaxone identified four extended broad-spectrum-lactamases (isoelectric points 7.6, 6.3, 7.0 and 5.9) produced by the strains.  相似文献   

15.
Summary YEp plasmid stability in the presence of either Saccharomyces cerevisiae laboratory strain 2-m DNA, or lager brewing yeast 2-m DNA in the same genetic background, was compared under non-selective culture conditions. It was found that YEp plasmids were more stably maintained in the presence of lager 2-m DNA under these conditions. By construction of laboratory-lager 2-m DNA hybrid plasmids, an 867 bp StuI fragment of lager 2-m DNA was shown to be responsible for the enhanced stability of the YEp plasmid. Nucleotide substitutions at two sites were found by sequencing this region. It was also confirmed that increasing cell ploidy enhanced YEp stability under non-selective conditions.  相似文献   

16.
The in vitro antibacterial activity of FK-037, a new parenteral cephalosporin structurally related to cefpirome and cefepime, was compared with that of cefotaxime, ceftazidime, aztreonam, cefpirome, cefepime, imipenem and meropenem against 1,837 clinical isolates obtained from three Spanish hospitals. FK-037 inhibited 90 % ofEnterobacteriaceae isolates at 0.25 µg/ml, with the exception ofEnterobacter aerogenes (MIC90 1 µg/ml),Enterobacter cloacae andCitrobacter freundii (MIC90 8 µg/ml). In cefotaxime-and ceftazidime-resistantKlebsiella pneumoniae strains producing SHV-2 and SHV-6 -lactamases, the activity of FK-037, cefpirome and cefepime was similar (MIC range 0.25–32 µg/ml). InEnterobacteriaceae strains hyperproducing chromosomally inducible -lactamases, FK-037 (MIC90 range, 0.25–8 µg/ml) was 8- to 16-fold more active than cefotaxime and ceftazidime but two- to eightfold less active than cefpirome and cefepime. FK-037 and cefpirome were twofold more active than ceftazidime and cefepime againstPseudomonas aeruginosa isolates, with MIC90 values of 16 µg/ml. The activity of FK-037, cefpirome and cefepime was two- to eightfold lower in ceftazidime-resistant derepressedPseudomonas aeruginosa mutants. FK-037 (MIC range, 0.12–2 µg/ml) and the other -lactam agents tested were active against methicillin-susceptible staphylococci; however, only cefpirome and, particularly, FK-037 (MIC90 of 32 µg/ml) displayed some activity against methicillin-resistant strains. In penicillin-susceptible,-intermediate and -resistantStreptococcus pneumoniae isolates, the MIC90s of FK-037 were 0.03, 0.5 and 1 µg/ml, respectively. The corresponding values forStreptococcus viridans isolates were 0.12, 1 and 8 µg/ml, respectively. In bothStreptococcus pneumoniae andStreptococcus viridans isolates, FK-037 displayed activity similar to that of cefotaxime and cefpirome and slightly higher than that of cefepime.  相似文献   

17.
The aim of the present study was to investigate the relationship between phenotypes ofCandida albicans strains isolated from clinical specimens and susceptibility of the strains to two antifungal agents, itraconazole and fluconazole. Oropharyngeal, gastrointestinal tract, and urogenital tract specimens were collected from 131 neutropenic patients withCandida infection who had received no previous prophylactic treatment. The most frequent species isolated wasCandida albicans, followed byCandida glabrata,Candida tropicalis, Candida krusei, andCandida parapsilosis. Each of the 44Candida albicans strains recovered was found to express one of four phenotypes: smooth, irregular, fuzzy or stipple. Mean minimum inhibitory concentrations (MICs) of itraconazole and fluconazole as determined by the microdilution method and the E-test were consistently higher forCandida albicans strains expressing the stipple phenotype. The mean MICs for the four phenotypes of theCandida albicans strains ranged between 0.35 g/ml and 2.41 g/ml for itraconazole and 2.78 g/ml and 5.2 g/ml for fluconazole. Antifungal susceptibility of the stipple phenotype requires careful appraisal, especially in patients clinically unresponsive to azole chemotherapy or in cases of life-threatening, deepseatedCandida infections.  相似文献   

18.
Summary A small population of T cells does not express the conventional T cell receptor characterized by the and polypeptide chains (TCR) but instead, two polypeptides termed and (TCR). This alternative receptor is able to recognize antigen. It appears early in T cell ontogeny, but its role in the thymus prior to the availability of TCR remains unclear. In selected sites such as skin or gut TCR predominates in mice which might suggest a role of T cells in the first line of defense against infection, T cells secrete lymphokines and display cytotoxic activity. However, their activation requirements may differ from what is known for T cells since MHC-nonrestricted and also CD4 and CD8 negative T cells have been described. Preferential activation by mycobacterial antigens possibly indicates a special repertoire of the T cells. In various diseases slightly increased numbers of T cells were found, but these preliminary studies have not yet provided evidence for a major pathogenetic role of T cells.List of abbreviations C constant region (immunoglobulin or TCR gene segment) - CD4 cluster of differentiation 4 (mainly on helper cells) - CD8 cluster of differentiation 8 (mainly on cytotoxic cells) - D diversity region (immunoglobulin or TCR gene segment) - DNA desoxyribonucleic acid - IL2 interleukin 2 - J joining region (immunoglobulin or TCR gene segment) - kD kiloDalton - MHC major histocompatibility complex - NK natural killer (cells) - RA rheumatoid arthritis - TCR T cell receptor - V variable region (immunoglobulin or TCR gene segment)  相似文献   

19.
In order to evaluate the suitability of fosfomycin in combination with other agents for the treatment of Helicobacter pylori infections, the susceptibility profiles of 65 H. pylori strains were determined against multiple antimicrobial agents and combinations thereof using the agar dilution method. For fosfomycin alone, the range of minimum inhibitory concentration (MIC) results and the MICs at which 50% and 90% of strains were inhibited were 0.5–32 g/ml and 2 and 4 g/ml, respectively. For the combination of fosfomycin with amoxicillin, clarithromycin or metronidazole, the means calculated for the minimum and maximum fractional inhibitory concentration index were 0.70–1.17 and 1.15–2.03, respectively, suggesting partial synergy or indifference in the majority of strains. The combination of clarithromycin and metronidazole showed synergistic activity against 14 of 28 H. pylori strains tested. The in vitro activity results suggest the combination of fosfomycin with either amoxicillin or clarithromycin may be a promising alternative for the treatment of H. pylori infection. However, the clinical efficacy of these regimens remains to be investigated.  相似文献   

20.
Auranofin, an oral chrysotherapeutic agent effective in the treatment of rheumatoid arthritis (RA), was found to be a potent, noncytotoxic inhibitor of IgG-RF immune complex-induced lysosomal enzyme release (LER) from human leukocytes. At a concentration of 1 g Au/ml (5M), auranofin produced a marked reduction in-glucuronidase (100%), acid phosphatase (88%), and lysozyme (72%) release. In contrast, gold sodium thiosulfate (GST, an injectable gold compound) had no inhibitory activity on LER at equivalent gold concentrations (i.e., 1g Au/ml) and only modest activity (< 36% inhibition) at concentrations as high as 40g Au/ml. The 50% inhibitory dose (ID50) of auranofin on LER was calculated to be 3–4M (0.6–0.8g Au/ml). Blood gold levels in auranofin-treated RA patients were found to be within the range required for in vitro inhibition of LER, and correlated with decreases in IgG, RF titers, and IgG-RF immune-complex formation in vitro. These results suggest that the therapeutic action of auranofin may be caused, at least in part, by inhibition of LER and/or decreases in immune-complex formation.SK&F D-39162 (2,3,4,6-tetra-O-acetyl-1-thio--D-glucopyranosato-S) (triethylphosphine) Gold.  相似文献   

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