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M Segovia

Publications and source records attributed to M Segovia.

At least 19 recordsLinked to original sources
PubMed2005

Sensitivity of urinary antigen test in relation to clinical severity in a large outbreak of Legionella pneumonia in Spain.

Presented here are the results of Legionella urinary antigen testing correlated with patient characteristics and severity of pneumonia (Fine score) in 295 patients diagnosed with Legionella pneumonia in connection with a large outbreak in Murcia, Spain. Overall, the sensitivity of the urinary antigen test was 47.7% (141/295). A statistically significant association was found between the clinical severity of pneumonia and test sensitivity; 85.7% for patients with severe pneumonia versus 37.9% for patients with mild pneumonia (risk ratio, 2.3). Variables significantly associated with test positivity in multivariate analysis were as follows: pre-existing pulmonary disease, body temperature >40 degrees C, leukocytosis and multilobar infiltrates. Patients with mild pneumonia may go undiagnosed if the urinary antigen test is used alone.

Antigens, Bacterial↗
PubMed2005

Fatal visceral leishmaniasis, with massive bone-marrow infection, in an immunosuppressed but HIV-negative Spanish patient, after the initiation of treatment with meglumine antimoniate.

Although visceral leishmaniasis is often fatal in the developing world, Leishmania-attributable deaths in Europe are relatively rare and nowadays almost always linked to HIV infection. In Spain, however, a HIV-negative man with a history of chronic obstructive pulmonary disease and prednisone treatment was recently hospitalized because of hypotension and asthenia. Although the patient was afebrile, a bone-marrow aspirate, collected after thrombo- and leuco-cytopenia had been observed, was found to contain huge numbers of amastigotes. A course of antileishmanial treatment with meglumine antimoniate was initiated but the patient went into refractory shock and died within 6 h. The significance of this case, in terms of the routine investigation and treatment of immunosuppressed patients who may have leishmaniasis, is discussed.

Antiprotozoal Agents↗
PubMed2003

Use of direct latex agglutination testing of selective broth in the detection of group B strepptococcal carriage in pregnant women.

Direct latex agglutination testing of selective broth medium for the detection of group B streptococci was evaluated. Results were compared with those obtained by the recommended subculture method. Among the 551 vaginal-rectal specimens tested, 101 (18.3%) were positive by the subculture method. Of these subcultures, latex agglutination testing detected 99 (98%) positive specimens. Agglutination testing of selective broth is a sensitive method which offers the advantage of saving 24 h in the turnaround time for detection of group B streptococci in pregnant women.

Adult↗
PubMed2003

[Antimicrobial susceptibility of Pseudomonas aeruginosa clinical isolates in Murcia, Spain].

The source and antimicrobial susceptibility of 1293 clinical isolates of Pseudomonas aeruginosa obtained from 1996 to 1999 were studied. Urine was the most common source for outpatient isolates (61.2%), while for hospitalized patients respiratory samples were the most frequent (40.2%). The most active antimicrobials with resistance rates <=10% were ceftazidime, imipenem, tobramycin and amikacin. By contrast, aztreonam, ciprofloxacin and gentamicin showed resistance levels >10%. The percentages of resistance to ceftazidime, aztreonam and imipenem in isolates from inpatients and from patients in the intensive care unit were significantly higher than those in isolates from outpatients and other clinical departments. Comparison of susceptibility data from 1996 to 1999 showed a significant increase in the resistance rate for all of the antibiotics studied but imipenem.

Anti-Bacterial Agents↗
PubMed2001

Light regulation of cyclic-AMP levels in the red macroalga Porphyra leucosticta.

Total cyclic-3'-5'-adenosine monophosphate (cAMP) levels were measured in the gametophyte of the red macroalga Porphyra leucosticta under different light conditions in order to study its regulation by phytochrome or photosynthesis. cAMP levels were relatively low when samples were incubated in darkness, or exposed to red or far-red light. Irradiation with red+far-red light induced a moderate increase in cAMP levels, while white light induced a pronounced increase in cAMP levels. When incubated under increasing white light irradiance, cAMP levels closely followed the increase in photosynthetic oxygen evolution rate, suggesting a direct relationship between photosynthesis and cAMP accumulation. cAMP levels were not dependent on cellular ATP concentration, as inhibitors of ATP synthesis did not significantly affect cAMP levels in light. We conclude that cAMP depends on photosynthetic activity regardless of ATP synthesis and concentration or phytochrome activity.

Adenosine Triphosphate↗
PubMed2001

[Occupational exposures to blood-borne pathogens in health care workers].

OBJECTIVE: To determine the rate of occupational exposures to blood-borne pathogens in different occupations of health care workers. To analyze the characteristics and outcome of the occupational exposure. MATERIAL AND METHODS: We have evaluate occupational exposures to blood-borne pathogens reported by health care workers during 1996-1999. The following data were collected: characteristics of the workers, type of occupational exposure, immunity status of the exposed worker, infectivity of the source patient and follow up serologic testing of the worker. RESULTS: A total of 407 occupational exposures were reported. The highest rate of occupational exposure was found among nurses (61.6%). Needlestick accident was the most often occupational exposure reported (84.5%). Mucosal exposures with accidental splashes were reported in 15.2% of cases. In 14.5% of these accidents workers were at risk for occupational transmission of blood-borne pathogens. Among the different occupations of health care workers, the rate of exposures with a source infected patient was higher in medical staffs (28.3%) than nurses (13.9%) The rate of exposures with a source infected patient was higher in accidental splashes than in percutaneous exposures (33.8% vs 13.3%), besides in none of the accidental splashes, employees had used appropriate barrier precautions. There were no cases of transmission of occupational blood-borne infections. CONCLUSIONS: Although nurses are the health care workers with highest rates of occupational exposures, medical staffs are the most often occupationally exposed to a source infected patient. Universal barrier precautions are no appropriately used in most of the occupational accidents, specially in those involving mucosal exposures.

Accidents, Occupational↗
PubMed2001

[Comparative study of 3 tests for susceptibility of Mycobacterium tuberculosis to first-line antituberculous drugs].

Treatment of tuberculosis requires a multidrug regimen for a prolonged period of time (6-12 months), which leads to a high level of noncompliance with therapy. This lack of compliance has led to an increase in drug-resistant strains of Mycobacterium tuberculosis. Rapid drug susceptibility tests are needed to assess effective chemotherapy regimens. In the present study, the reliability of ESP Myco System II(R) and E-test(R) for determining the susceptibility of 82 clinical isolates of M. tuberculosis to rifampin, isoniazid, streptomycin and ethambutol was evaluated by comparing results to those of the multiple proportion method as a reference. ESP Myco System II(R) is a nonradioactive, totally automated, continuously monitored system designed to detect grown mycobacteria. E-test(R) is a well-described method of susceptibility testing which provides data on minimal inhibitory concentration. The susceptibility results of both methods were available within 9 days, while those of the proportion method required 28 days. Levels of agreement between ESP Myco System II(R) and the proportion method for the clinical isolates analyzed were 100% for rifampin, isoniazid and ethambutol. Only one discrepancy was found for streptomycin. For the E-test(R), the results were less favorable. ESP Myco System II(R) was shown to be a rapid and reliable method for testing susceptibility of M. tuberculosis isolates. Nevertheless, E-test(R) provided low specificity for streptomycin and ethambutol. Further studies to test the reliability of the E-test(R) are necessary.

Antitubercular Agents↗
PubMed2000

Flow cytometric evaluation of antibiotic effects on viability and mitochondrial function of refrigerated spermatozoa of Nile tilapia.

Improved techniques for storage and evaluation of fish sperm would enhance breeding programs around the world. The goal of this study was to test the effect of antibiotics on refrigerated sperm from Nile tilapia (Oreochromis niloticus) by use of flow cytometry with 2 dual-staining protocols for objective assessment of sperm quality. Concentrations of 1 x 10(9). sperm/mL were suspended in Ringer's buffer at 318 mOsmol/kg (pH 8.0). The fluorescent stains Sybr 14 (10 microM), propidium iodide (2.4 mM), and rhodamine 123 (0.13 microM) were used to assess cell viability and mitochondrial function. Three concentrations of ampicillin, gentamicin, and an antibiotic/antimycotic solution were added to fresh spermatozoa. Motility estimates and flow cytometry measurements were made daily during 7 d of refrigerated storage (4 degrees C). The highest concentrations of gentamicin and antibiotic/antimycotic and all 3 concentrations of ampicillin significantly reduced sperm viability. The highest of each of the 3 antibiotic concentrations significantly reduced mitochondrial function. This study demonstrates that objective sperm quality assessments can be made using flow cytometry and that addition of antibiotics at appropriate concentrations can lengthen refrigerated storage time for tilapia spermatozoa. With minor modifications, these protocols can be adapted for use with sperm from other species and with other tissue types.

Animals↗
PubMed2000

Detection of mycoloylglycerol by thin-layer chromatography as a tool for the rapid inclusion of corynebacteria of clinical origin in the genus Corynebacterium.

A chemotaxonomic study of some corynebacteria isolated from clinical samples revealed characteristic thin-layer chromatographic patterns for meso-diaminopimelic acid containing species included in the genera Corynebacterium, Dermabacter and Brevibacterium. Notably, a specific compound was consistently detected in mycolic acid containing species of the genus Corynebacterium. This compound was composed by glycerol and mycolic acids and structural analyses carried out by fast atom bombardment mass spectrometry in C. minutissimum confirmed its identification as mycoloylglycerol. The chain length of mycoloyl groups in this molecule ranged from 28 to 34 carbon atoms, being mono-, di- or triunsaturated. Detection of mycoloylglycerol by thin-layer chromatography may be thus useful for the rapid inclusion of a great variety of corynebacteria of clinical origin in the genus Corynebacterium in laboratories employing chromatographic techniques as an adjunct for the identification of these microorganisms.

Brevibacterium↗
PubMed2000

[ROC curve analysis of factors predictive of non-response to interferon treatment in patients with chronic hepatitis C, genotype 1].

The objectives of this study included: 1) to identify pretreatment variables predictive of absence of response in 107 patients with chronic hepatitis C, genotype 1, treated with interferon-a (IFN-a) at a dose of 3 MU three times weekly for 3-12 months and classified into two groups: group A, nonresponders vs. patients with a complete response, and group B, nonresponding and relapsing patients vs. patients with a sustained response; and 2) to establish a prognostic index using ROC curve analysis. The rate of sustained response was 6. 5% at the 24-month follow-up. The pretreatment characteristics with predictive value using ROC curves were as follows: in group A, age, GGT, serum ferritin, viral load, and grade and stage of the histological lesion; and in group B, known duration of infection, GPT, GGT, serum ferritin, viral load, and grade and stage of the histological lesion. In both group A and group B the positive predictive value (the probability of predicting an absence of response when the variable is present) was greater than the negative predictive value (mean: 84.3% vs. 41.1%, 99% vs. 16.5%, respectively). In group A, based on the prognostic index, the positive predictive value when three variables were present was 96% and the sensitivity was 63.5%, with the test being unequivocal in 6.5%, whereas when four or five variables were present, the positive predictive value was 97% and 100% and the sensitivity was 40.5% and 18%, respectively. In group B, the positive predictive value when two variables were present was 100% and the sensitivity was 87%, whereas when three, four, five and six variables were present the sensitivity was between 73% and 28%. In group A, age, GGT and ferritin were the predictive variables independently associated with an absence of response, with a relative risk of 6.5, 4.8 and 3.1, respectively, whereas in group B we did not find variables independently associated with an absence of response. It was concluded that in patients with genotype 1, it is possible to predict the absence of response to IFN therapy with a high degree of reliability.

Adolescent↗
PubMed2000

[ROC curve analysis of factors predictive of no response to interferon treatment in patients with chronic hepatitis C, genotype 1]

The objectives of this study included: 1) to identify pretreatment variables predictive of absence of response in 107 patients with chronic hepatitis C, genotype 1, treated with interferon-a (IFN-a) at a dose of 3 MU three times weekly for 3-12 months and classified into two groups: group A, nonresponders vs. patients with a complete response, and group B, nonresponding and relapsing patients vs. patients with a sustained response; and 2) to establish a prognostic index using ROC curve analysis. The rate of sustained response was 6.5% at the 24-month follow-up. The pretreatment characteristics with predictive value using ROC curves were as follows: in group A, age, GGT, serum ferritin, viral load, and grade and stage of the histological lesion; and in group B, known duration of infection, GPT, GGT, serum ferritin, viral load, and grade and stage of the histological lesion. In both group A and group B the positive predictive value (the probability of predicting an absence of response when the variable is present) was greater than the negative predictive value (mean: 84.3% vs. 41.1%, 99% vs. 16.5%, respectively). In group A, based on the prognostic index, the positive predictive value when three variables were present was 96% and the sensitivity was 63.5%, with the test being unequivocal in 6.5%, whereas when four or five variables were present, the positive predictive value was 97% and 100% and the sensitivity was 40.5% and 18%, respectively. In group B, the positive predictive value when two variables were present was 100% and the sensitivity was 87%, whereas when three, four, five and six variables were present the sensitivity was between 73% and 28%. In group A, age, GGT and ferritin were the predictive variables independently associated with an absence of response, with a relative risk of 6.5, 4.8 and 3.1, respectively, whereas in group B we did not find variables independently associated with an absence of response. It was concluded that in patients with genotype 1, it is possible to predict the absence of response to IFN therapy with a high degree of reliability.

Journal Article↗
PubMed2000

Receiver operating characteristics curve analysis of factors predictive of nonresponse to interferon therapy in patients with chronic hepatitis C.

OBJECTIVES: 1) to identify pretreatment variables predictive of nonresponse to interferon-alpha (IFN-alpha) in patients with chronic hepatitis C, and 2) to establish a prognostic index in these groups using receiver operating characteristics curve analysis. METHODS: 132 patients were treated with IFN-alpha at a dose of 3 megaunits three times a week for 3-12 months. The response was compared in patients with a complete response vs nonresponders, and patients with a sustained response vs nonresponders plus relapsers. Factors predictive of response were identified by analyzing clinical, biochemical, virological and histological variables. RESULTS: The sustained response rate was 12.8% at 24 months of follow-up. The pretreatment characteristics with a predictive value (PV) according to area under the ROC curve and 95% confidence interval > 0.5 were age, known duration of infection, history of transfusion, GGT, serum ferritin levels, viral load, genotype, and grade and stage of the histological lesion. The positive PV (the probability of predicting absence of response when the variable is present) was notably greater than the negative PV (mean: 94.9% vs 24.8%, respectively). In addition, when 4 and 6 variables were present, the positive PV was 100% and sensitivity was 60.2% and 22.1%, respectively. The predictive variables independently associated with an absence of response were genotypes 1, 4 and 5, GGT > 24 IU/l and grade of the histological lesion > 6. CONCLUSIONS: It was possible to predict the absence of both primary and posttreatment response with an acceptable degree of reliability.

Adult↗
PubMed1998

Appearance of resistance to meropenem during the treatment of a patient with meningitis by Acinetobacter.

A case is reported of a patient who developed Acinetobacter meningitis after an external ventricular drainage system had been fitted for control of intracranial pressure. During the process, nine strains of Acinetobacter isolated from her cerebrospinal fluid were indistinguishable by analysis of total genomic DNA by pulse-field gel electrophoresis. The first eight strains were sensitive to meropenem and imipenem (MICs < 1 g/l). The MIC of the last one, which had been recovered after 32 days during two courses of treatment with meropenem, increased to > 32 g/l for meropenem, while with imipenem the increase was minimal (MIC = 1.5 g/l). The microorganism persisted in the central nervous system despite the administration of different antimicrobials, including intraventricular aminoglycosides and six changes in the external ventricular system. The patient died 68 days after admission to the intensive care unit from bilateral cerebral ischemic lesions, intraventricular hemorrhage and cerebral edema with endocraneal hypertension, the Acinetobacter ventriculitis also contributing to this state.

Acinetobacter↗
PubMed1997

Acyl phosphatidylglycerol: a major phospholipid of Corynebacterium amycolatum.

The type strain and several clinical isolates of Corynebacterium amycolatum were examined for lipid composition as a chemotaxonomic character for routine identification. The phospholipid profile was composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides, together with various unidentified compounds. One of them, accounting for 20-29% of total phospholipids, was purified and characterized as acyl phosphatidylglycerol by chromatographic and spectrometric techniques. The acyl substituents on the phosphatidyl moiety were characterized as tetradecanoyl, pentadecanoyl, hexadecenoyl, hexadecanoyl, heptadecenoyl, heptadecanoyl, octadecenoyl (the major one), and octadecanoyl. The acyl group on the polar head (glycerol) was only octadecenoyl. Phospholipid analysis by thin-layer chromatography of a collection of Corynebacterium strains proved that this compound is widely distributed, although it only represents a minor (2-9%) component among mycolic acid-containing species. Acyl phosphatidylglycerol can be considered as a useful chemical marker for the identification of C. amycolatum in addition to the absence of mycolic acids.

Corynebacterium↗
PubMed1997

Assessment of multiple coagulase-negative staphylococci isolated in blood cultures using pulsed-field gel electrophoresis.

One of the criteria used to determine the clinical importance of coagulase-negative staphylococci (CNS) is the isolation of the bacteria from sequential blood cultures. Sequential isolates of CNS obtained from five immunocompromised patients over three months were genetically characterized by pulsed-field gel electrophoresis (PFGE). This typing method was compared to two first-line typing methods: determination of the species and of antibiotic susceptibility. In four patients the initial clinical evaluation changed because of the PFGE results several episodes of bacteremia would have been wrongly assessed if only the biotype and the antibiotype had been determined. Pulsed-field gel electrophoresis should therefore be used for CNS strains from immunocompromised patients or those suffering from chronic diseases with non-concordant biotype and anti-biotype.

Adult↗
PubMed1997

LD1 amplifications in Leishmania.

The genome of Leishmania is quite plastic. Chromosomal rearrangements and DNA amplifications are common events in all the species of the genus. Gene amplification occurs both as a mechanism of drug resistance and in the absence of drug pressure. The best known spontaneous amplification in Leishmania is the so-called LD1 family of amplicons. In the past few years there have been great advances in our knowledge of LD1 elements; here, Manuel Segovia and Ginés Ortiz review all the available data.

Journal Article↗