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C Fuster

Publications and source records attributed to C Fuster.

45 records · Page 3Linked to original sources
PubMed1983

Plasmid-determined beta-lactamases identified in a group of 204 ampicillin-resistant Enterobacteriaceae.

Information is presented on the plasmid-determined beta-lactamases identified in 204 strains of ampicillin-resistant Enterobacteriaceae. The type most frequently identified was TEM-1 (in 85.3% of the strains), followed by SHV-1 (14.70%). Two types of plasmid-determined beta-lactamase were identified in 20 strains; in 18 of them one of the two was TEM-1 and in 13, SHV-1 (the TEM-1 + SHV-1 combination was observed in 12 strains). In the 41 Klebsiella strains the most frequently identified enzyme was SHV-1 (in 28 of the strains) and the proportion of strains with two plasmid-determined beta-lactamases was higher than in the other species studied.

Ampicillin↗
PubMed1982

Complementary activity of mezlocillin and the combination of amoxicillin with clavulanic acid on Enterobacteriaceae.

The MICs of amoxicillin, mezlocillin and BRL 25,000, a combination of two parts amoxicillin and one part clavulanic acid (2AM + 1CA), were measured for 331 Enterobacteriaceae strains which produced beta-lactamases as demonstrated by nitrocefin. The MIC values for mezlocillin and the combination 2AM + 1CA were very similar for the total number of the strains investigated. When investigated separately according to the bacterial species, three different sensitivity groups were established for the above-mentioned preparations: 1) species with the same or similar sensitivity to mezlocillin and 2AM + 1CA (Escherichia coli and Shigella spp., amoxicillin-resistant strains); 2) species which were more sensitive to mezlocillin than to the combination 2AM + 1CA (Citrobacter spp., Enterobacter cloacae, Serratia spp. and indole-positive Proteus as well as strains of E. coli and Shigella spp. which produce a cephalosporinase and are sensitive to amoxicillin); 3) species which are more sensitive to 2AM + 1CA than to mezlocillin (amoxicillin-resistant Salmonella spp., Proteus mirabilis and Klebsiella pneumoniae). This complementary activity of mezlocillin and 2AM + 1CA against Enterobacteriaceae depended on the beta-lactamases produced.

Amoxicillin↗
PubMed1981

[Cefsulodin, a new antibiotic of the group of cephalosporins: its action on Pseudomonas aeruginosa (author's transl)].

Cefsulodin is a new second generation cephalosporin with a narrow antibacterial spectrum. Its main use is in the treatment of Pseudomonas aeruginosa infections. It is resistant to the action of the beta-lactamases of gram negative bacilli, especially to that of the cephalosporinases. We have studied 170 strains of P. aeruginosa and 10 of other species of Pseudomonas, determining the MIC by the serial dilution test in solid medium and the sensitivity by the agar diffusion test. With 8 microgram/ml, a concentration which is accepted as a limit of sensitivity from the therapeutic point of view, 90% of the P. aeruginosa strains studied are inhibited; the MIC50 is obtained with 2 microgram/ml. Within the strains considered sensitive (MIC less than 8 microgram/ml) there is a marked dispersion of the zone diameters corresponding to each of the values of MIC. This behavior limits the value of the regression line. We have also studied the MIC of carbenicillin for nearly all the strains and we have also studied the MIC of carbenicillin for nearly all the strains and we have found that 86.58% are sensitive to both preparations, 4.96% are sensitive to cefsulodin and resistant to carbenicillin, 4.02% resistant to cefsulodin and sensitive to carbenicillin and 4.69% are resistant to both preparations. From the clinical point of view the number of strains sensitive (or resistant) is similar with both substances but cefsulodin is in absolute values from 8 to 128 times more day active than carbenicillin. Cefsulodin is administered by a parenteral route and is eliminated by the urine in active form. The recommended therapeutic dose for the treatment of systemic infections is 2 g daily IV. This dose may be increased if it is considered advisable. There is good local tolerance (IM and IV), it is only slightly toxic, hardly alters the intestinal flora and may be used at all ages, in patients with immunological alterations and in patients with an altered renal function.

Carbenicillin↗
PubMed1980

[Studies on antibacterial activity of cephotaxime (HR 756), a new antibiotic of the cephalosporin group (author's transl)].

Cephotaxime (HR 756) is a new cephalosporin antibiotic of wide spectrum and extraordinary activity, suitable for parenteral administration. It is highly resistant to the beta-lactamases of Gram negative bacilli, being thus especially active against microorganisms such as indole-positive Proteus, Serratia marcencens, and others usually resistant to most beta-lactamic antibiotics because of their ability to produce beta-lactamases of high activity. The sensitivity of 355 different bacterial strains to cephotaxime has been determined by the disc method, along with the minimal inhibitory concentration (MIC) of the drug to the same strains, and regression lines have been constructed. The extraordinary activity of cephotaxime against Enterobacteriaceae, Vibrio Cholerae, Haemophilus, and Neisseria meningitidis is noteworthy. Of the 220 strains of Enterobacteriaceae studied, 55% produced beta-lactamase. The MIC of cephotaxime for beta-lactamase forming strains was similar to that for non-forming strains.

Cefotaxime↗
PubMedDate not supplied

Spontaneous chromosome fragility in chorionic villus cells.

Human fragile sites are only very rarely expressed spontaneously. In this paper we report the presence of non-random spontaneous chromosome lesions (CL) in chorionic villus samples and their coincidence with fragile site (FS) bands. The average number of CL was about 9% both in RPMI-1640 and in Chang media. To determine any possible influence of external factors other than culture media, the results were grouped according to age of gestation. No differences were observed among the different groups. A total of 101 chromosome lesions could be precisely identified by sequential Leishman Staining/Wright G-banding; 76.2% of them coincided with FS-bands. The most affected region was at 1q12-1q21.1 (15.8% of total CL); other FS with a clustering of breakpoints in our study were 1p36, 1q44, 2q37, 3p24, 3q27, 10q22 and 16q23. These results suggest that spontaneous expression of some FS could be a characteristic of embryonic tissues.

Cells, Cultured↗
PubMedDate not supplied

[Characterization of plasmids in Escherichia coli strains].

BACKGROUND: Strains of Escherichia coli are frequently plasmid carriers. In this species, resistance to beta-lactam antibiotics is almost always conditioned by the production of enzymes coded by plasmidic genes. The present is a study of the plasmids of 44 ampicillin-sensitive strains and 134 ampicillin-resistant (ampS and ampR). The possibility that the number and size of the plasmids are different and that this data may be added to the information to be considered in these two groups of strains is suggested. METHODS: The 178 strains selected had been isolated from human products. Sensitivity to ampicillin was studied by diffusion and was confirmed with the study of MIC (Mueller-Hinton agar, innoculum: 5 x 10 CFU). The plasmid type beta-lactamases were identified by analytical isoelectrofocus. Characterization of the plasmids was performed according to a variant of the Birnboim and Doly alkaline lysis technique. RESULTS: Among the ampR and ampS strains no plasmid were observed in 9 (6.72%) and 11 (25%) respectively. The mean number of plasmids was 2.53 and 1.57, ranging between 0-10 and 0-5. The number of strains with plasmids larger than, or equal to, 38 Kb was 113 and 27 respectively. The largest plasmids observed in the ampS strains were of 99 Kb and in the ampR of 109 Kb. A total of 3.73% of the ampR strains presented plasmids larger than 99 Kb and 8.20% more than 5 plasmids. CONCLUSIONS: No plasmids, presence of up to five and sizes smaller than or equal to 99 Kb were observed in strains of ampS and ampR. The presence of more than five and/or plasmids larger than or equal to 100 Kb was observed in 11.94% of the ampR.

Ampicillin Resistance↗