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Biomedical subjects

L Cellini

Publications and source records attributed to L Cellini.

50 records · Page 3Linked to original sources
PubMed1988

Purification and characterization of three forms of glutathione transferase from Proteus mirabilis.

Three forms of glutathione transferase (GST) with pI values of 6.0, 6.4 and 7.3 were isolated from Proteus mirabilis AF 2924 by glutathione-affinity chromatography followed by isoelectric focusing, and their structural, kinetic and immunological properties were investigated. Upon SDS/polyacrylamide-slab-gel electrophoresis, all forms proved to be composed of two subunits of identical (22,500) Mr. GST-6.0 and GST-6.4 together account for about 95% of the total activity, whereas GST-7.3 is present only in trace amounts. Extensive similarities have been found between GST-6.0 and GST-6.4. These include subunit molecular mass, amino acid composition, substrate specificities and immunological characteristics. GST-7.3 also cross-reacted (non-identity) with antisera raised against bacterial GST-6.0. None of the antisera raised against a number of human, rat and mouse GSTs cross-reacted with the bacterial enzymes, indicating major structural differences between them and the mammalian GSTs. This conclusion is further supported by c.d. spectra.

Amino Acids↗
PubMed1988

Inhibition of plasmid conjugation by some recently synthetized 4-quinolone compounds.

Four fluoroquinolones (norfloxacin, ciprofloxacin, ofloxacin, and pefloxacin) were compared with nalidixic acid for their inhibitory effect on conjugal plasmid transfer. The inhibition was observed in mating experiments using various combinations of drugs at subinhibitory concentrations and 3 different plasmids in the E. coli k12 genetic background. Fluoroquinolones inhibited plasmid transfer to a greater extent than nalidixic acid. Ofloxacin and pefloxacin were consistently the most active agents, causing 90 to 100% inhibition of plasmid transfer in all mating systems studied.

Anti-Infective Agents↗
PubMed1988

In vitro activity of pefloxacin compared with five other quinolones on nalidixic acid-resistant proteae species.

The in vitro activity of pefloxacin, a new fluoroquinolone, was compared with that of 5 other quinolone compounds (nalidixic and pipemidic acids, norfloxacin, ciprofloxacin, and ofloxacin) against 416 strains of Proteae spp. isolated from urine specimens of hospitalized patients with acute urinary tract infections (UTI). Ciprofloxacin was the most active agent. Norfloxacin, ofloxacin, and pefloxacin were similarly active against Proteus strains (MIC90 = 0.39 microgram/ml). Against Providencia spp. pefloxacin and norfloxacin showed similar activity (MIC90 = 3.12 micrograms/ml). There is minimal discrepancy between minimum inhibitory concentrations and minimum bactericidal concentrations exhibited by the quinolones for all urinary tract pathogens tested. Our in vitro studies indicate that pefloxacin is an active antimicrobial agent and suggest that it will prove useful in the treatment of complicated urinary tract infections due to nalidixic acid-resistant Proteae spp.

Anti-Infective Agents↗
PubMed1988

Effect of pefloxacin on adherence of Proteus-Providencia spp to squamous epithelial cells.

Pefloxacin, a new piperazinyl substituted quinolone derivative, reduced at sub-MICs (Minimal Subinhibitory Concentrations: four times lower than Minimal Inhibitory Concentrations) the in vitro adherence of Proteus-Providencia spp. to squamous epithelial cells obtained from the urinary tract. The decrease of adherence was about 30% and 50% after 1 h and, respectively, 16-18 h of incubation with pefloxacin. This finding suggests that pefloxacin may play a role in determining the in vivo adhesion of Proteus-Providencia spp. on the urinary tract and consequently the expression of bacterial pathogenic potency.

Adult↗
PubMed1987

Comparative in vitro activities of 13 antimicrobial agents against Morganella-Proteus-Providencia group bacteria from urinary tract infections.

We examined 741 urinary tract isolates of the Morganella-Proteus-Providencia group, including the recently defined species Proteus penneri, for susceptibilities to aminoglycosides, semisynthetic penicillins, and cephalosporins. The data emphasize the importance of identification to the species level on the basis of marked species differences in patterns of susceptibility.

Anti-Bacterial Agents↗
PubMed1987

Preliminary studies on the effect of glutathione S-transferase from Providencia stuartii on the antimicrobial activity of different antibiotics.

Glutathione S-transferase has been isolated and purified from a Providencia stuartii CH 114 strain. The effect of the enzyme on the antimicrobial activity of amikacin, cefotaxime, cephalexin, ampicillin, nalidixic acid, and ofloxacin was tested. The efficiency of all antibiotics tested, except nalidixic acid and ofloxacin, is relevantly decreased by the presence of glutathione S-transferase in the medium culture, as proved by the increased value of MIC. The effect of glutathione S-transferase on the drugs is not significantly affected by the addition of exogenous glutathione. The possible mechanism of action of the enzyme is also discussed.

Anti-Bacterial Agents↗
PubMed1987

Adhesive properties of Proteus genus related to antimicrobial agents resistance.

The in vitro attachment of 49 Proteus spp. to human urinary tract epithelial cells was determined. The antibacterial spectrum to all species of the Proteus isolates from hospitalized patients was measured against the most common antibiotics (Amikacin, Cefamandole, Cefoxitin, Ceftriaxone, Cephalothin, Kanamycin, Nalidixic acid, Oxolinic acid, Pipemidic acid, Piromidic acid, Tobramycin). 18 of them were multiresistant and the other 31 expressed susceptibility to the above antibiotics. Bacterial adherence to uroepithelial cells was studied in relation to susceptibility on antibiotics. The mean of bacteria per cell for the 31 strains grouped as susceptible was 20.2 and for the 18 strains grouped as resistant the mean was 55.1. Our results demonstrate a significant relationship between bacterial adhesion and antibiotic susceptibility pattern by Student's t test (P less than 0.01).

Adult↗
PubMed1984

[In vitro antibacterial activity of ciprofloxacin against uropathogenic organisms].

Ciprofloxacin (Bay 09867) is a new quinoline derivative. Its activity against 537 urinary bacterial isolates was compared with those of ampicillin, amikacin, carbenicillin, cefazolin, cefotaxime, cefoxitin, ceftazidime, nalidixic and oxolinic acids, norfloxacin, trimethoprim, and other antimicrobial agents, when appropriate. It inhibited 90% Citrobacter freundii, Enterobacter spp., E, coli, Klebsiella spp., Proteus spp., and Serratia spp. at less than or equal to 0.78 microgram/ml. The majority of Pseudomonas aeruginosa, including gentamicin-resistant strains, was inhibited by less than or equal to 3.12 micrograms/ml. MICs of Bay 09867 for 90% of Staphylococcus aureus, including methicillin-resistant strains, and Streptococcus faecalis were 0.78 micrograms/ml and 1.56 micrograms/ml respectively. Bay 09867 inhibited organisms resistant to ampicillin, carbenicillin, cefazolin, nalidixic and oxolinic acids and trimethoprim.

Anti-Infective Agents, Urinary↗
PubMed1984

In vitro synergism of nalidixic acid with other broad spectrum antibiotics.

In vitro studies of the activity of antibiotic combinations in the ratio 1:1: nalidixic acid plus cephaloridine, nalidixic acid plus kanamycin and nalidixic acid plus erythromycin were performed by using an agar dilution technique with Mueller-Hinton Agar. Of 156 Enterobacteriaceae tested, nalidixic acid plus cephaloridine were synergistic for 96 (61.5%) strains compared with 101 (64.7%) with nalidixic acid plus kanamycin (P less than 0.01) and 85 (54.5%) with nalidixic acid plus erythromycin (P less than 0.001). These data suggest these combinations as possible effective tools in clinical trials, especially directed toward high level resistant urinary tract pathogens.

Anti-Bacterial Agents↗
PubMed1983

[In vitro anti-fungal activity of the econazole-ornidazole combination (1:10 ratio)].

The antifungal activity of Econazole-Ornidazole combination (ratio 1:10) has been evaluated against 90 strains of Candida spp. recently isolated from a clinical environment. Minimal Inhibitory Concentrations (MICs) has been determined by a dilution broth method in test tube with Mycophil Broth (B.B.L) at pH 7.00 and drug concentrations ranging from 800 micrograms/ml to 0.2 microgram/ml. By the same technics it has been determined the pH influence of growth medium, human serum and fungal inoculum on the activity of the association towards the three strains of Candida spp.: C. albicans, C. krusei and C. tropicalis. The obtained data have shown that the Econazole-Ornidazole combination actuates a sure synergic effect towards the tested Candida strains. Such synergism is met at pH 8.00. The plasma proteins influence negatively the antifungal activity of the association proportionally to the increase of the concentration. The same thing happens with the inoculum of yeast. However, this decrease of activity of the association is always smaller than the one found in the compounds alone.

Antifungal Agents↗
PubMedDate not supplied

[Urinary tract infection in an ambulatory population: epidemiological analysis of the etiology and antibiotic resistance of isolated gram-negative strains].

15,892 urinocultures belonging to out-patients admitted to Chieti ULSS 04, from January '85 to December '89 were studied. Among the examined samples, the positive urinocultures were 4255 (26.8%) with a prevalence in the female sex (78.6%). During the year E. coli was the most frequently identified organism (55.8%) without significant changes. 25.7% was the isolation percentage of Morganella-Proteus-Providencia (MPP). In order to plan a right antibiotic-therapy the resistance of isolates to 19 chemo-antibiotics, during five years, was evaluated and compared.

Adult↗