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M A Bratos

Publications and source records attributed to M A Bratos.

15 recordsLinked to original sources
PubMed2000

[Laboratory diagnosis and serologic course in patients with tularemia].

BACKGROUND: Tularemia was practically unknown in Spain until the end of 1997, when an epidemic outbreak was declared. This paper presents the data on microbiological diagnosis of 55 patients who suffered from tularemia. PATIENTS AND METHODS: Thirty-two samples from 19 patients and 151 serum samples from 55 patients were obtained for culture. Serologic diagnosis was performed by tube sero-agglutination and microagglutination. Three types of tests were performed on all sera: Wright sero-agglutination (WSA), Coombs test against Brucella spp. and sero-agglutination against Yersinia enterocolitica O:3, Yersinia enterocolitica O:3, and Proteus OX 19. RESULTS: F. tularensis was found in two samples (6.25%) of the 32 received. Titers > or = 1/160 were obtained in 78.2% and 74.5% of the initial sera by tube sero-agglutination and microagglutination, respectively. Correlation between the two tests was 0.80 (p < 0.001). Prozone phenomenon was observed in 59.9% of the sera, while crossed reactivity to Brucella spp. and Proteus spp. was found in 9.3% and 22.8%, respectively. No crossed reactivity was observed with Yersinia spp. CONCLUSIONS: Culture of F. tularensis has low sensitivity. The correlation obtained between tube sero-agglutination and microagglutination is good. Both techniques are useful in routine diagnosis of tularemia, although microagglutination has some advantages over tube agglutination.

Adult↗
PubMed2000

Evaluation of an immunocapture-agglutination test (Brucellacapt) for serodiagnosis of human brucellosis.

We evaluated the validity and the usefulness of a new test for the diagnosis of human brucellosis based on an immunocapture-agglutination technique. A total of 315 sera from 82 patients with a diagnosis of brucellosis, 157 sera from patients in whom brucellosis was suspected but not confirmed, and 412 sera from people living in rural areas with endemic brucellosis were studied. The seroagglutination test (SAT), Coombs anti-Brucella test, and Brucellacapt test were evaluated. All the initial sera from the 82 patients proved to be positive in Brucellacapt and Coombs tests, while only 75 (91.4%) were positive in the SAT. If a >/=1/160 diagnostic threshold titer was defined for the Brucellacapt test, Coombs test, and SAT, the sensitivities were 95.1, 91.5, and 65.8%, respectively. Taking the same diagnostic threshold titer for the 157 sera from the unconfirmed but suspected patients, the specificities of the Brucellacapt, Coombs, and SAT were 81.5, 96.2, and 100%, respectively; for the 412 control sera, the specificities were 99.0, 99.8, and 100%. The diagnostic efficiency (area below the receiver operating characteristic curve) of Brucellacapt was 0.987852 (95% confidence interval [CI], 0.95109 to 0.99286), very similar to the diagnostic efficiency of the Coombs test (0.97611; 95% CI, 0.94781 to 0.99146) and higher than that of SAT (0.91013; 95% CI, 0.86649 to 0.94317). The results of the Brucellacapt test were compared with those of the Coombs test (correlation coefficient, 0.956; P = 0.000) and SAT (correlation coefficient, 0.866; P = 0.000). The study shows very good correlation between the Brucellacapt and Coombs tests, with a high concordance between titers obtained in the two tests. Nevertheless, lower correlation and concordance were found between the Brucellacapt and Coombs tests when the results for titers of >/=1/160 were compared (0.692; P = 0.000). In acute brucellosis, the Brucellacapt and Coombs tests render positive titers of >/=1/160. When the titers are lower, they increase significantly in the following 30 days, despite the evolution of SAT titers. In contrast, Brucellacapt and Coombs titers are always high (>/=1/640) in brucellosis with long evolution, whether SAT titers are higher or lower than 1/160.

Adolescent↗
PubMed1999

Evaluation of six serological tests in diagnosis and postoperative control of pulmonary hydatid disease patients.

Latex agglutination (LA), passive hemagglutination (PHA), immunoelectrophoresis (IEP) and specific IgE, IgM, IgG enzyme-linked immunosorbent assay (ELISA) tests for diagnosis and postoperative follow-up of 79 patients with surgically confirmed pulmonary hydatidosis were evaluated. Specific IgG ELISA was the most sensitive test (83.5%) and the least sensitive tests were specific IgE ELISA (44.3%) and IEP (50.6%). The specificity obtained for all the serologic test was above 97% in all cases. The greatest number of false positives in all tests (except IEP) occurred in patients with Taenia saginata and Taenia solium cysticerci infestations and in patients with lymphoma and leukemia. Specific IgG ELISA demonstrated the highest negative predictive value (93.8%). No statistically significant differences (p > 0.050) were found in the sensitivity of the tests when patients with only one cyst and patients with various cysts were compared. Considering only the patients without relapse, the percentage of seropositive patients increased in all tests at 1 and 3 months after surgery. After that time the percentage of seropositive patients decreased. At 48 months after surgery all patients without relapse became negative in IEP, specific IgE ELISA, and specific IgM ELISA. The antibody titers in all seropositive patients increased during the 3 months after surgery. From these 3 months onward, antibody levels decreased in all serologic tests studied in the group of patients without relapse. The patients who had relapses during the first year after surgery presented persistently elevated antibody titers in all postoperative sera. The antibody titers of the patients who relapsed between the third and fourth years after surgery decreased progressively the third month after surgery, and increased in the serum obtained at the moment of relapse diagnosis. Our results show that persistence of elevated antibody titers in patients with pulmonary hydatidosis in the year after surgery or titer increase after a progressive decrease are indicative of relapse or reinfection.

Antibodies, Helminth↗
PubMed1998

Clinical evaluation of a commercial ligase-based gene amplification method for detection of Mycobacterium tuberculosis.

The purpose of this study was to evaluate the clinical usefulness of a commercial ligase-based gene amplification method (LCx Mycobacterium tuberculosis test; Abbott Laboratories, USA) for detection of Mycobacterium tuberculosis. The tuberculosis infection rate among clinical samples was 10.6%. The sensitivity, specificity, and positive and negative predictive values were 23.5%, 100%, 100%, and 91.7%, respectively, with the fluorochrome auramine stain; 32.4%, 100%, 100%, and 92.6%, respectively, with culture; and 76.5%, 95.8%, 68.4% and 97.2%, respectively, with the gene amplification method. When only samples from patients without current or previous treatment were studied, the sensitivity was 36.4% with the auramine stain, 63.6% with culture, and 100% with the gene amplification assay. The mean treatment time for culture-negative and assay-negative samples was greater than that of culture-negative and assay-positive samples. The LCx Mycobacterium tuberculosis test is a sensitive method for detection and identification of Mycobacterium tuberculosis. It produces few false-positive results. However, as it can remain positive after the culture becomes negative, it is not recommended for evaluation of treatment efficiency.

Bacteriological Techniques↗
PubMed1998

[Variants of hepatitis C virus in different risk groups. Comparative study of a method for genotyping and another for serotyping].

AIMS: The aim of this study was to know the prevalence of the different variants of HCV in the Health Care area of Monforte de Lemos (Lugo, Spain) and its distribution according to risk factors and to compare the results obtained with one genotyping and one serotyping technique. PATIENTS AND METHODS: Eighty-four patients with hepatitis C were studied, 25 of whom were IVDA, 14 had received blood transfusions, 4 hemodialysis and the risk factor was unknown in 41. The antibodies against HCV were studied by second generation EIA and confirmed by an immunoblot technique. Serotyping was carried out by an ELISA test. Genotyping was undertaken with a reverse hybridation test of the amplification obtained by polymerase chain reaction prior to reverse transcription (RT-PCR). RESULTS AND CONCLUSIONS: The genotypes most frequently observed were 1b (47.6%), 1a (20.2%) and 3 (14.3%). In the IVDA patients the genotypes 1a (40%) and 3 (24%) predominated. The 1b genotype was the most prevalent in the patients of unknown risk (68.3%) and patients with a history of blood transfusion (50%). The prevalence of the different serotypes was similar to that of the corresponding genotypes, with nearly 100% agreement. The number of untypable cases was greater in the serotyping technique (20.2%) than in the genotyping (2.4%). A greater number of mixed infections was detected with serotyping (7 cases, 8.3%) than with genotyping (1 case, 1.2%). Lesser sensitivity of the serotyping test was observed in the patients lacking anti-NS4 antibodies.

Blood Transfusion↗
PubMed1992

Infection by hepatitis B and C virus in non-intravenous drug using female prostitutes in Spain.

We have studied the prevalence of hepatitis B (HBV) and hepatitis C virus (HCV) serologic markers in female blood donors and in female prostitutes and the relationship of antibodies to hepatitis B core antigen (anti-HBc) and of antibodies to HCV (anti-HCV) with the presence of treponemal antibodies (FTA-ABS) in non-intravenous drug using female prostitutes. Hepatitis B surface antigen (HBsAg) was found in 1.0% of the female blood donors, anti-HBc in 15.6% and anti-HCV in 0.7%. In the prostitutes, the prevalence of HBsAg was 6.1%, anti-HBc was positive in 29.0% and anti-HCV in 8.8%. No significant statistical association between the prevalence of anti-HBc or anti-HCV and the age of prostitutes (p = 0.9111 and p = 0.8254 respectively) or the length of time as prostitutes (p = 0.3583 and p = 0.5770) was found. FTA-ABS positive prostitutes had a significantly higher prevalence of anti-HCV than FTA-ABS negative prostitutes (p < 0.001). No statistical association was found between anti-HBc antibodies and positive FTA-ABS prostitutes (p = 0.336).

Adolescent↗
PubMed1991

Inhibition of the degranulation and myeloperoxidase activity of human polymorphonuclear neutrophils by Brucella melitensis.

The degranulation and myeloperoxidase-H2O2-halide activities of human polymorphonuclear leukocytes from healthy donors were tested after co-incubation with either Brucella melitensis 16M, Staphylococcus aureus or Staphylococcus aureus in presence of lipopolysaccharide, protein fraction, native hapten and soluble fractions released at 65 degrees C from smooth strain of Brucella melitensis 16M. The degranulation and myeloperoxidase activities of polymorphonuclear leukocytes were significantly higher when co-incubated with Staphylococcus aureus than with Brucella melitensis. The presence of lipopolysaccharide, protein fraction, and native hapten did not cause significant modification of either degranulation or myeloperoxidase activities of polymorphonuclear leukocytes against Staphylococcus aureus. Soluble fraction released at 65 degrees C produced a significant reduction in the myeloperoxidase activity but did not alter the degranulation of polymorphonuclear leukocytes triggered by Staphylococcus aureus.

Brucella↗
PubMedDate not supplied

Prevalence of anti-hepatitis C virus antibodies in positive FTA-ABS non-drug abusing female prostitutes in Spain.

The prevalence of antibodies against Hepatitis C Virus (anti-HCV antibodies) and its association with the presence of treponemal antibodies (FTA-ABS) was studied in 227 non-drug abusing female prostitutes. The overall anti-HCV antibody prevalence was 8.8%, and a significantly higher prevalence of anti-HCV antibodies was found in prostitutes testing positive for FTA-ABS (19.4%) than in prostitutes testing negative for FTA-ABS (3.9%) (PR = 5.023, P less than 0.001). No statistical association was found between patient age or the duration of prostitution and the presence of anti-HCV antibodies.

Adult↗
PubMedDate not supplied

[A e year study of the electrophoretic RNA patterns of rotavirus in Valladolid].

BACKGROUND: To study the electrophoretic RNA patterns of human rotavirus (RV) during three years in Valladolid (Spain). MATERIAL AND METHODS: From october 1986 to october 1989 we have studied the electrophoretic RNA patterns of RV in 104 fecal samples. Stools were first screened by a latex agglutination test (LA) and reactive samples were confirmed by a commercial enzymeimmunoassay (EIA) and electron microscopy (EM) (negative stain). Electropherotyping was made according to conventional methods. RESULTS: 96.2% of the samples studied yield a defined electropherotype. We have found 8 different types of patterns of genomic RV-RNA circulating in these three years. Two of them belonged to short pattern (C and E) and six to long pattern (A, B, D, F, G and H). CONCLUSIONS: 98.0% of the genomic RNA founded were of long pattern, from which pattern A was the most prevalent (72%) during the study, without a seasonal distribution. Pattern B was found in 20% of cases, while the rest were found only occasionally.

Child↗