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Biomedical subjects

R Cisterna

Publications and source records attributed to R Cisterna.

At least 19 recordsLinked to original sources
PubMed2000

Specific and rapid identification of multiple-antibiotic resistant Pseudomonas aeruginosa clones isolated in an intensive care unit.

Seventeen multiple-antibiotic-resistant Pseudomonas aeruginosa isolates were collected from two patients hospitalized in the same intensive care unit. They showed a parallel acquisition of resistance to antibiotics and they were, therefore, thought to have a common clonal origin. These strains were typed by biotyping, serotyping, plasmid profile, three different PCR-based techniques, and macrorestriction analysis to determine their relationship. Only the use of PCR techniques and macrorestriction analysis allowed an accurate identification of the clones and revealed that each patient was infected by A unique multidrug-resistant strain. Therefore, there was no cross-infection or reinfection with a new strain.

Anti-Bacterial Agents↗
PubMed1999

Detection of HGV in serum and peripheral blood mononuclear cells of maintenance haemodialysis patients.

The aim of the present study was to investigate the prevalence of hepatitis G virus (HGV) and also hepatitis C virus (HCV) infections in maintenance haemodialysis patients, and to identify extrahepatic sites as HGV reservoirs. HGV RNA was detected in the serum of 6/61 (10%) patients and in the peripheral blood mononuclear cells of 2/61 (3%) patients (one of whom was serum negative). These findings suggest that lymphoid cells constitute an extrahepatic HGV reservoir. HCV RNA was detected in 7/61 (11%) patients. Five of these patients (71%) were identified as carrying HCV genotype 1b. Co-infection with HCV and HGV was detected only in one patient. Haemodialysis patients are at risk for HGV infection, by nosocomial routes or via transfusions. HGV itself does not seem to be an important cause of hepatitis since all six HGV RNA positive patients not co-infected by HCV or HBV showed normal ALT values.

Adult↗
PubMed1999

Late disappearance of hepatitis C virus RNA from peripheral blood mononuclear cells in patients with chronic hepatitis C in sustained response after alpha-interferon therapy.

OBJECTIVE: We aimed to investigate the modifications of HCV RNA (genomic and antigenomic strands) in peripheral blood mononuclear cells (PBMCs) of long-term responder patients to alpha-interferon therapy, and their usefulness as criteria of definitive HCV eradication. METHODS: We studied 10 patients with chronic hepatitis C with > 1 yr of sustained response after alpha-interferon therapy (normal alanine aminotransferase [ALT] and negative serum HCV RNA). Serum HCV RNA and genotyping were determined. Approximately 2 and 4 yr after completion of treatment we investigated the presence of HCV RNA (genomic and antigenomic strands) in PBMCs. Eight of 10 patients were rebiopsed 2 yr after discontinuation of treatment. RESULTS: The mean follow-up was 46.6 +/- 4.6 months (range, 39-51 months). In this period, all patients remained in sustained response. In the first determination, all patients had HCV RNA genomic strands and two patients had antigenomic strands detectable in PBMCs. Two years later only two patients had genomic and none had antigenomic strands detectable. After 4 yr of sustained response, eight of 10 patients lost HCV RNA from PBMCs. CONCLUSIONS: In the long-term follow-up, the majority of patients with chronic hepatitis C with sustained response after alpha-interferon therapy progressively lost HCV RNA from PBMCs. This determination in PBMCs is not a predictor of response.

Adolescent↗
PubMed1999

Epidemiological analysis of sequential Pseudomonas aeruginosa isolates from chronic bronchiectasis patients without cystic fibrosis.

PCR fingerprinting was used for the epidemiological investigation of 64 Pseudomonas aeruginosa isolates collected from 16 chronic bronchiectasis patients without cystic fibrosis: 56% of the patients harbored one clone, 12.5% carried a single major type with minor variants, and 31.5% carried two clones. Only a minority of the acquisitions of antibiotic resistance was related to the acquisition of exogenous strains. Mucoid and nonmucoid sets of isolates did not display any consistent differences in their patterns. The genetic similarity among the clones ranged from 10 to 69%. Cross-infection or common-source exposure did not appear to have occurred.

Bronchiectasis↗
PubMed1999

[Evaluation of mutations that confer resistance to nucleoside analogs and protease inhibitors in HIV-1-infected patients. Study Group on Resistance to Antiretroviral Agents].

Genotypes that confer drug resistance to reverse transcriptase inhibitors and protease inhibitors were evaluated in HIV-1 proviral DNA obtained from peripheral blood mononuclear cell samples. Fifty-three HIV-1-infected patients were studied, 19 of whom had not received antiretroviral treatment. In the other 34 patients, 9 had been treated with combinations of two reverse transcriptase inhibitors (AZT, ddI, d4T, 3TC) and 25 had been treated with triple antiretroviral therapy including a protease inhibitor (nelfinavir, indinavir, saquinavir, ritonavir). To determine the presence of mutations involved in the development of resistance to reverse transcriptase inhibitors a hybridization Microtiter assay was carried out. Mutations were detected in treated patients as well as in those without previous antiretroviral treatment, with the most frequent mutations being those that confer resistance to AZT, followed by those that develop cross-resistance to ddI/ddC and 3TC, which are the most commonly used drugs to date. No mutations were detected to any nucleoside analog in only 13 cases. To analyze the presence of mutations in the protease gene a dot-blot hybridization was carried out which included the mutations in codons 36, 82 and 90. Mutation 82 was detected in one case. Therefore, with the aim of determining the pattern of genotypic mutations in patients infected with HIV-1 and in order to make the best therapeutic choice, it would be recommended to consider carrying out genotypic resistance assays in clinical practice.

Anti-HIV Agents↗
PubMed1999

[Multicenter study of resistance in enterococci. The role of teicoplanin. Spanish Group for Study and Surveillance of Resistance].

Enterococci are a frequent cause of nosocomial and community infections, especially the E. faecalis and E. faecium species. They often show intrinsic resistance to cephalosporins and quinolones, and acquired resistance to other antimicrobials, such as glycopeptides, has also been described. In order to test the impact of antibiotic resistance in enterococci isolated from infections, we carried out a multicenter study in 19 hospitals in Spain. We verified whether resistance to a high concentration of aminopenicillins and aminoglycosides was high (30.86% for ampicillin, 32.32% for gentamicin at a 500 micrograms dose, 55.93% for streptomycin at a 1000 micrograms dose) while the resistance to glycopeptides was low (1.8% for vancomycin and 1% for teicoplanin). It was also shown that teicoplanin had greater intrinsic activity than vancomycin, with teicoplanin 0.5 mg/l inhibiting 86.1% of the strains studied, whereas only 12.8% were inhibited with the same concentration of vancomycin.

Anti-Bacterial Agents↗
PubMed1999

[Evaluation of mutations that confer resistance to nucleoside analogs and protease inhibitors in HIV-1-infected patients]

Genotypes that confer drug resistance to reverse transcriptase inhibitors and protease inhibitors were evaluated in HIV-1 proviral DNA obtained from peripheral blood mononuclear cell samples. Fifty-three HIV-1-infected patients were studied, 19 of whom had not received antiretroviral treatment. In the other 34 patients, 9 had been treated with combinations of two reverse transcriptase inhibitors (AZT, ddI, d4T, 3TC) and 25 had been treated with triple antiretroviral therapy including a protease inhibitor (nelfinavir, indinavir, saquinavir, ritonavir). To determine the presence of mutations involved in the development of resistance to reverse transcriptase inhibitors a hybridization Microtiter assay was carried out. Mutations were detected in treated patients as well as in those without previous antiretroviral treatment, with the most frequent mutations being those that confer resistance to AZT, followed by those that develop cross-resistance to ddI/ddC and 3TC, which are the most commonly used drugs to date. No mutations were detected to any nucleoside analog in only 13 cases. To analyze the presence of mutations in the protease gene a dot-blot hybridization was carried out which included the mutations in codons 36, 82 and 90. Mutation 82 was detected in one case. Therefore, with the aim of determining the pattern of genotypic mutations in patients infected with HIV-1 and in order to make the best therapeutic choice, it would be recommended to consider carrying out genotypic resistance assays in clinical practice.

Journal Article↗
PubMed1998

[Genetic typing by PCR of isolates of C. albicans obtained in a resuscitation unit].

BACKGROUND: Typing by PCR (random polymorphic amplification or arbitrarily primed PCR) consists in a random amplification with the use of initiators of unknown homology with respect to the mold sequence. This study is of interest given the development of the technology of the amplification of nucleic acids and its application in the epidemiologic characterization of isolates of C. albicans. METHODS: Fourteen strains isolates in blood cultures of 8 patients were studied. All were identified as C. albicans. For amplification the sequence of AP3 and ERIC2 were selected. RESULTS: With one strain a band pattern very different from that obtained with the remaining isolates identified as C. albicans was achieved leading to reidentification and proving that it was C. parapsilopsis. On combining the results obtained with the use of both initiators 7 different genotypes were obtained with the remaining strains: A1, 2B, 3C, 4C, 5D, 6B and 7E. CONCLUSIONS: The discriminative power of the two initiators was similar although the AP3 was greater obtaining one more genotype than ERIC2. The patients with repeated yeast isolates over time which may be considered as the same episode of bacteremia, each presented the same band pattern and each was infected by one single clone. We herewith confirm the usefulness of typing by PCR with one initiator by reaction. The results may be improved with the combination of the profiles obtained with the use of several sequences if greater discrimination is required. Likewise, its use has shown to be satisfactory in both the identification of clones within one species and the identification of species within the genus.

Candida albicans↗
PubMed1998

Detection of anti-interferon-gamma autoantibodies in subjects infected by Mycobacterium tuberculosis.

SETTING: Among the cytokines involved in defensive mechanisms against Mycobacterium tuberculosis infection, special attention has been given to interferon-gamma (IFN-gamma); a local synthesis of this cytokine as well as IL-2 (type 1 cytokines) at the site of disease in patients with tuberculous pleuritis has been demonstrated. Moreover, high levels of IgG autoantibodies against IFN-gamma have been shown in several clinical situations. It has been suggested that these antibodies could serve to limit the intensity or duration of the immune response or be able to interfere with the pathophysiological effects of IFN-gamma. OBJECTIVE: To investigate the potential role of anti-IFN-gamma antibodies in the course of M. tuberculosis infection. DESIGN: Investigation of the presence of these antibodies in sera from healthy and ill subjects infected with M. tuberculosis in relation to the extent of the disease and the presence of IFN-gamma in sera by enzyme-linked-immunosorbent assay (ELISA). In order to investigate the presence of these antibodies at the site of infection we included 12 pleural fluids from tuberculosis patients and 9 pleural fluids from other origins. RESULTS: In the course of M. tuberculosis infection the production of anti-IFN-gamma IgG antibodies is induced, being particularly higher in healthy skin test converters. Among tuberculosis patients, the presence of anti-IFN-gamma autoantibodies is significantly associated with detectable levels of the cytokine in sera. Levels of anti-IFN-gamma antibodies in moderately advanced and far advanced tuberculosis patients are significantly greater than in healthy individuals. These antibodies increase at the site of infection. CONCLUSION: Anti-IFN-gamma antibodies must be considered as a new element in the immune response to M. tuberculosis. It would be of great interest to investigate this point especially at the site of infection.

Antibody Specificity↗
PubMed1998

[Ampicillin-sulbactam activity against respiratory isolates of Haemophilus influenzae].

A study was conducted on the in vitro activity of ampicillin/sulbactam against 100 respiratory strains of Haemophilus influenzae (45 betalactamase positive and 55 betalactamase negative strains) simultaneously isolated during 1997 in 6 Spanish hospitals: Hospital Clínico San Carlos (Madrid), Hospital de Cruces de Basurto (Bilbao), Hospital La Fe (Valencia), Hospital Virgen Macarena (Seville), Hospital de Bellvitge (Barcelona) and Hospital Clínico Universitario (Salamanca). It was studied in comparison to amoxicillin, amoxicillin/clavulanic acid, cefuroxime, clarithromycin and ciprofloxacin. The MIC breakpoints used for the interpretation of data were those published by the National Committee for Clinical Laboratory Standards in 1997. All of the strains tested were susceptible to ampicillin/sulbactam, amoxicillin/clavulanic acid, cefuroxime and ciprofloxacin. The rate of resistance to clarithromycin was 55.5% for betalactamase positive strains and 38. 2% for betalactamase negative strains. A total of 23.6% of the betalactamase negative strains were resistant or showed intermediate susceptibility to amoxicillin but were susceptible to betalactam/betalactamase inhibitor combinations and cefuroxime.

Amoxicillin↗
PubMed1997

Kinetics of allergen expression in cultures of house dust mites, Dermatophagoides pteronyssinus and D. farinae (Acari: Pyroglyphidae).

Laboratory cultures of house dust mites Dermatophagoides pteronyssinus (Trouessart, 1897) and Dermatophagoides farinae Hughes, 1961 were used to study the population dynamics of the mites and the kinetics of antigen appearance. The analysis of extracts obtained after different incubation periods, carried out by SDS-PAGE, immunoblotting, and enzyme-linked immunosorbent assay, allows for the definition of 3 different growth phases: the latency phase (F1); the exponential growth phase (F2) during which the allergenic proteins, including the Der 1 and Der 2 major allergens, were expressed more intensely and in larger quantities; and a final phase (F3), death, in which the lowest rates of allergenic components with a clearly different pattern were seen. The data obtained from this work demonstrates that mite cultures during the maximum growth phase (F2) contain the largest amount of allergenic components as well as the highest major allergen concentrations.

Allergens↗
PubMed1997

In vitro activity of fosfomycin trometamol against pathogens from urinary tract infections: a Spanish multicenter study.

The in-vitro susceptibilities of a total of 1371 urinary tract pathogens to fosfomycin trometamol were determined. According to the NCCLS breakpoints, Enterobacteriaceae and gram-positive microorganisms were, in general, very sensitive to this antimicrobial. More than 90.0% of the Escherichia coli and Citrobacter spp. and more than 70.0% of the Klebsiella pneumoniae, K. oxytoca, Enterobacter spp., Proteus mirabilis, Staphylococcus aureus, coagulase-negative staphylococci and Enterococcus spp. strains tested were susceptible to fosfomycin trometamol. However, Pseudomonas aeruginosa and Acinetobacter spp. strains were more resistant. In general, recent clinical isolates from urinary tract infections (UTIs) in both community and hospital were also very sensitive (> 80.0%) to fosfomycin, its activity being higher than that of the rest of the antimicrobials commonly used for therapy of uncomplicated UTIs. More than 75.0% of the most frequently isolated pathogens from UTIs, except for P. aeruginosa (31.8%) and Acinetobacter spp. (11.1%), were susceptible to fosfomycin trometamol. The results obtained in this study, together with the infrequency of side effects and its pharmacokinetic properties, indicate that fosfomycin trometamol may be a useful alternative for single-dose therapy of uncomplicated UTIs.

Anti-Bacterial Agents↗