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V Ausina

Publications and source records attributed to V Ausina.

At least 73 records · Page 4Linked to original sources
PubMed1997

Occurrence of an antigenic triacyl trehalose in clinical isolates and reference strains of Mycobacterium tuberculosis.

A careful re-examination of the glycolipid content of clinical isolates and reference strains of the tubercle bacillus, Mycobacterium tuberculosis, led to the identification of a glycoconjugate that passed unnoticed in earlier studies. Nuclear magnetic resonance spectroscopy, gas chromatography-mass spectrometry and chemical degradations were used to identify the glycolipid as a 2,3,6-triacyl trehalose. The glycolipid contains a phthienoic acyl substituent, a family of multimethyl-branched, alpha,beta-unsaturated fatty acids specific for virulent strains of the tubercle bacillus. It reacted with sera from tuberculosis patients with a specificity and sensitivity of 96.2% and 76%, respectively. Comparable data were obtained with the 2,3-diacyl trehaloses of M. tuberculosis and M. fortuitum and with the triacyl trehaloses of M. fortuitum, suggesting that the antigens from the latter species may be used for the serodiagnosis of tuberculosis.

Antibodies, Bacterial↗
PubMed1997

Easy differentiation of Mycobacterium mucogenicum from other species of the Mycobacterium fortuitum complex by thin-layer and gas chromatography of fatty esters and alcohols.

The mycolate pattern of a recently recognized mycobacterial pathogen, Mycobacterium mucogenicum (formerly Mycobacterium chelonae-like organism), was established for the first time. The reference strains, together with 31 environmental and clinical isolates belonging to this species, were examined for their mycolate composition by thin-layer chromatography. All strains tested exhibited the same mycolate profile. Mycolates were identified as belonging to the type without additional oxygenated chemical groups (mycolate I) and the type with a dicarboxylic group (mycolate VI); the identification of the latter was reinforced by the presence of 2-octadecanol, as seen by gas-liquid capillary chromatography. This mycolate profile permits the clear differentiation of M. mucogenicum from other related species, as members of the Mycobacterium fortuitum complex. This fact is especially important-because strains of M. mucogenicum are very difficult to differentiate from other species of the M. fortuitum complex by means of conventional biochemical tests. Moreover, the characteristic mycolate profile exhibited by the strains of M. mucogenicum supports the recent proposal which considers them as members of a new species.

Base Sequence↗
PubMed1997

Multicenter clinical comparison of resin-containing bottles with standard aerobic and anaerobic bottles for culture of microorganisms from blood.

In a study comparing the Bactec 9240 (Plus Aerobic/F and Anaerobic/F bottles, containing resins; Becton Dickinson, USA) and the Vital (standard aerobic and anaerobic bottles, with no additives; bioMérieux, France) blood culture systems, 6456 sets of four bottles of 9660 blood cultures submitted were evaluated. There were 531 clinically significant isolates from 795 positive blood cultures. Of the 531 positive blood cultures, 355 were positive in both systems, 141 with the Bactec 9240 alone, and 30 with the Vital alone (p < 0.001); five were not detected by either system. The average time to detection of positive cultures for the matched sets was 10.65 h and 18.41 h by the Bactec 9240 system and the Vital system, respectively. The false-positive rate per bottle was 0.65% in the Bactec 9240 and 0.71% in the Vital. The rate of false-negative pairs (i.e., major errors) was very low (0.12% for the Bactec 9240, 0.19% for the Vital) and not significantly different between the two systems. The striking differences in recovery of microorganisms may be due to the presence of resins in the Bactec medium. However, the observed superiority of the Bactec 9240, even for patients not receiving antibiotics, suggests that resins adsorb other inhibitors present in patients' blood.

Adult↗
PubMed1997

Inactivation of hepatitis B virus: evaluation of the efficacy of the disinfectant 'Solprogel' using a DNA-polymerase activity assay.

The effects of sodium dichloroisocyanurate (NaDCC) and Solprogel (Laboratorios Inibsa, S.A., Barcelona, Spain), a compound that contains NaDCC plus a biodegradable polymer of acrylic acid, on the activity of DNA polymerase (DNA-P) associated with hepatitis B virus in serum were evaluated. DNA-P positive and negative pools of human serum samples were used as positive and negative stock virus. Inhibition of DNA-P activity by NaDCC and the commercial product was found to be concentration-dependent. Two minutes exposure to the minimum effective concentration of NaDCC (1000 ppm available chlorine) or Solprogel 16% (960 ppm available chlorine) totally inhibited DNA-P activity.

Antiviral Agents↗
PubMed1997

[Comparative study of acute and chronic forms of pleural tuberculosis].

To analyze whether a characteristic pattern distinguishes acute forms (symptoms starting no more than one week earlier) and subacute or chronic forms (symptoms lasting more than one week) of pleural tuberculosis (PT) in our practice. Retrospective analysis of 102 cases of PT diagnosed between 1986 and 1992, comparing the findings of case histories, imaging, pleural biochemistry and cytology, microbiology of sputum, pleural biopsy and fluid, anatomy and pathology studies of the biopsy specimens, course of disease, response to treatment and sequelae after one year and a half. Thirty-two patients (31.4%) had acute PT and 70 (68.6%) had chronic forms. LDH levels and the percentage of pleural nuclear polymorphism were higher in acute cases, while the concurrence of systemic involvement and lymphocytic predominance was more often seen in chronic cases. Other data analyzed were similar in both groups. No specific clinical or X-ray profiles or differences in course of disease and response to treatment distinguishes between acute and chronic forms of PT after 7 days. Only LDH levels and cytology results differentiated acute forms and, occasionally, such cases were indistinguishable from pneumonia-like effusion.

Acute Disease↗
PubMed1997

Distribution of surface-exposed antigenic glycolipids in recent clinical isolates of Mycobacterium tuberculosis.

The distribution of surface-exposed antigenic glycolipids in seven recent clinical isolates of Mycobacterium tuberculosis was established. Thin-layer and liquid chromatographies revealed a uniformity in the glycolipid pattern. Chemical analysis of the individual glycolipids of a selected strain enabled the identification of glycolipids of serological interest in all the other clinical isolates. Phenolic glycolipid-Tb1 (PGL-Tb1) was lacking in all strains, but appreciable amounts of a partially deglycosylated version (PGL-Tb1D) were present in the seven isolates. Diacyltrehaloses (DATs) were detected in all strains, showing themselves to be major glycolipids. Lipooligosaccharides (LOS-II) were present in the seven strains studied though only in trace amounts. These results shed new light on the open debate on the distribution of these interesting glycolipids in typical clinical isolates of M. tuberculosis. In the search for a serological test for tuberculosis, and in accordance with our observations, we believe that PGL-Tb1 and LOS-II should not be the target molecules for serology and that it is worthwhile to continue investigating the value of DATs as antigens. We also believe that it would be of interest to undertake research to assess the usefulness of PGL-Tb1D as an antigen.

Antigens, Bacterial↗
PubMed1997

Direct detection of Mycobacterium tuberculosis complex in nonrespiratory specimens by Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test.

The Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (AMTDT) was adapted for the detection of Mycobacterium tuberculosis complex in 224 nonrespiratory specimens from 188 patients. The sensitivity and specificity of the AMTDT for such specimens, after resolution of discrepant results, were 85.7 and 100%, respectively. Pretreatment of nonrespiratory specimens with sodium dodecyl (lauryl) sulfate is mandatory to obtain consistent and reproducible AMTDT results. The use of 500 microliters of decontaminated specimen improves the sensitivity of the test. Because the AMTDT detects stable rRNA from noncultivable bacilli, it is not useful for monitoring patients receiving treatment.

Bacterial Typing Techniques↗
PubMed1997

Detection of lipoarabinomannan antibodies in patients with newly acquired tuberculosis and patients with relapse tuberculosis.

A commercially available dot immunoassay that employs the lipoarabinomannan antigen was evaluated for the serologic diagnosis of tuberculosis. The test showed a high specificity (100%); however, its sensitivity was low (18.5%). Antibodies to lipoarabinomannan were detected in the sera of 7 of 71 patients with newly acquired tuberculosis and in sera of 10 of 21 patients with relapse tuberculosis. It has been shown by others that sera from patients with relapse tuberculosis had a higher concentration of antibodies and reacted with a greater variety of antigens (native culture filtrates of Mycobacterium tuberculosis H37Rv) than did sera from patients with newly acquired tuberculosis. Our data confirm the results of these previous studies as far as lipoarabinomannan is concerned. We conclude that the differences in the production of antibodies shown by the two groups of tuberculous patients (new and relapse) must be taken into account when assessing the usefulness of serologic tests for the diagnosis of tuberculosis.

Antibodies, Bacterial↗
PubMed1997

Comparison of radioimmunoassay and enzyme immunoassay kits for detection of Legionella pneumophila serogroup 1 antigen in both concentrated and nonconcentrated urine samples.

We evaluated a commercial enzyme immunoassay (EIA) kit for detection of Legionella pneumophila serogroup 1 soluble antigen by comparing it to radioimmunoassay (RIA), using both concentrated and nonconcentrated urine samples. The sensitivity of EIA was 67.4% in nonconcentrated urine samples and 82.6% in concentrated urine samples. The sensitivity of RIA was 60.9% and 84.8% in nonconcentrated and concentrated urine samples, respectively. Our study indicates that the sensitivity and specificity of EIA are comparable to those of RIA, and that concentrating the antigen by selective ultrafiltration increases sensitivity for both EIA and RIA, with no significant decrease in specificity.

Adult↗
PubMed1997

Evaluation of the semiautomated Abbott LCx Mycobacterium tuberculosis assay for direct detection of Mycobacterium tuberculosis in respiratory specimens.

Five hundred twenty processed respiratory specimens from 326 patients received for the diagnosis of tuberculosis or other mycobacterial infections were tested by means of the LCx Mycobacterium tuberculosis Assay from Abbott Laboratories, which uses ligase chain reaction technology for the direct detection of M. tuberculosis complex in respiratory specimens. The results of the LCx M. tuberculosis Assay were compared with the results of culture and staining techniques. After a combination of culture results and the patient's clinical data, a total of 195 specimens were collected from 110 patients who were positively diagnosed as having pulmonary tuberculosis. Twenty-three of these 195 specimens which corresponded to 10 patients with a history of pulmonary tuberculosis (TB) and anti-TB treatment ranging from 1 to 6 months were culture negative. The other 172 specimens were culture positive for M. tuberculosis. With an overall positivity rate of 37.5% (195 of 520 specimens), the sensitivity, specificity, and positive and negative predictive values were 90.8, 100, 100, and 94.7%, respectively, for the LCx M. tuberculosis Assay; 88.2, 100, 100, and 93.4%, respectively, for culture; and 82.6, 92, 72.9, and 97.6%, respectively, for acid-fast staining. For 161 specimens (82.6%) from patients smear positive for the disease and 34 specimens (17.4%) from patients smear negative for the disease, the sensitivity values for the LCx M. tuberculosis Assay were 98.8 and 53%, respectively. There were no statistically significant differences in the sensitivities and specificities between the LCx M. tuberculosis Assay and culture (P > 0.05). Conclusively, the LCx M. tuberculosis Assay has proved to have an acceptable sensitivity and a high specificity in detecting M. tuberculosis and has the potential of reducing the diagnosis time to an 8-h working day.

Bacterial Typing Techniques↗
PubMed1997

Detection and identification of mycobacteria by amplification of RNA and DNA in pretreated blood and bone marrow aspirates by a simple lysis method.

A sodium dodecyl (lauryl) sulfate method was evaluated for the preparation of blood specimens and bone marrow aspirates for use in two amplification procedures (Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test [AMTDT] and Roche Amplicor M. avium/M. intracellulare [MAI] Test) for the detection and identification of Mycobacterium tuberculosis and M. avium and M. intracellulare, respectively. The AMTDT is based on amplification of rRNA, whereas the Amplicor MAI Test amplifies a specific DNA region of the 16S rRNA gene. The results of amplification techniques were compared with those of standard culture and culture in BACTEC 13A and BACTEC 12B liquid media. A total of 121 blood specimens and 15 bone marrow aspirates were collected from 136 AIDS patients. Mycobacterial growth was recovered for 103 specimens; 35 yielded M. tuberculosis, 62 yielded M. avium, 5 yielded M. genavense, and 1 yielded M. kansasii. The values of sensitivity and specificity in pretreated specimens for detection of M. tuberculosis by the AMTDT were 94.3 and 100%, respectively, and those for detection of M. avium by the Amplicor MAI Test were 91.9 and 100%, respectively. The simple lysis method described in the present work allows the recovery of mycobacteria from blood specimens and bone marrow aspirates and may be used in combination with the AMTDT and the Amplicor MAI Test to detect and identify different members of the genus Mycobacterium. This method might also be applicable for the identification of mycobacteria from blood culture fluids with acridinium-ester-labeled DNA probes.

AIDS-Related Opportunistic Infections↗
PubMed1997

Pancoast's syndrome due to chronic pneumonia by Pasteurella multocida.

Infectious causes of Pancoast's syndrome are extremely rare. We describe the case of a patient with Pancoast's syndrome due to chronic pneumonia resulting from Pasteurella multocida. The patient was not immunosuppressed and had had no contact with animals. The diagnosis was made by transthoracic needle aspiration and institution of therapy with cefuroxime-axetil resulted in resolution of his symptoms.

Adult↗
PubMed1997

Rapid detection of Mycobacterium tuberculosis in respiratory specimens, blood and other non-respiratory specimens by amplification of rRNA.

SETTING: Diagnostic methods employing gene technology based on amplification of DNA or RNA are expected to improve the speed, sensitivity, and specificity of Mycobacterium tuberculosis detection. The Amplified Mycobacterium Tuberculosis Direct Test (AMTDT) enables the amplification and detection of M. tuberculosis rRNA directly from respiratory specimens. OBJECTIVE: To evaluate the performance of the AMTDT in direct detection of M. tuberculosis in respiratory specimens, blood and other clinical samples, and to compare this method with conventional culture and staining techniques. DESIGN: A total of 554 samples from 450 patients were examined in this study. All clinical specimens (with the exception of bone marrow aspirates and blood samples) were digested and decontaminated with sodium dodecyl (lauryl) sulfate (SDS)-NaOH. Bone marrow aspirates and blood samples were treated with 10% SDS. All processed samples were stained by auramine-rhodamine fluorochrome and inoculated onto Löwenstein-Jensen and Coletsos solid media, and into BACTEC-12B medium. In addition, the blood samples were inoculated into BACTEC 13A medium. The AMTDT was performed according to manufacturer's instructions. In those cases where discrepant results were obtained for AMTDT and cultures, patients' clinical data and other microbiological results were evaluated. RESULTS: The sensitivity, specificity, and positive and negative predictive values for AMTDT were 87.5, 100, 100, and 96.7%, respectively, in respiratory specimens and 86.8, 100, 100, and 92.8%, respectively, in non-respiratory specimens. The differences in sensitivity of these two groups of specimens were not highly statistically significant (P > 0.005). CONCLUSION: The sensitivity and specificity of the AMTDT were satisfactory for detection of M. tuberculosis in all types of clinical samples. Some minor changes in assay format and laboratory protocols may increase the sensitivity of the AMTDT without adversely affecting its specificity.

Bacteriological Techniques↗
PubMed1996

Selective intestinal decontamination with norfloxacin reduces bacterial translocation in ascitic cirrhotic rats exposed to hemorrhagic shock.

Bacterial translocation (BT) can be involved in the pathogenesis of severe infections due to bacteria of enteric origin that complicates bleeding cirrhotic patients. To assess the effect of hemorrhagic shock (HS) on the incidence of BT and if selective intestinal decontamination (SID) reduces this incidence, we studied six groups of Sprague-Dawley rats: ascitic rats, ascitic rats exposed to HS with and without previous norfloxacin prophylaxis, healthy rats, and healthy shocked rats with and without previous norfloxacin prophylaxis. BT tended to be higher in ascitic rats with shock than without shock (69% vs. 41%, P = .15) and was significantly higher in healthy rats with than without shock (50 percent vs. 0 percent, P = .01). Norfloxacin significantly reduced translocation in ascitic shocked rats in comparison with nondecontaminated ascitic shocked rats (31 percent vs. 69 percent, P = .038). This effect was due mainly to a reduction of gram-negative BT (O percent vs. 37 percent, P = .008). In addition, norfloxacin prevented translocation in healthy shocked rats. Accordingly, aerobic gram-negative bacteria disappeared from fecal flora in all rats administered norfloxacin, except for Klebsiella species in one control rat. Cecal severe submucosal edema, chronic inflammatory infiltrate, and intestinal lymphangiectasia were significantly more frequent in ascitic rats than in control rats. Intestinal mucosal injury related with HS, particularly subepithelial cecal edema, was observed only in ascitic shocked rats. In conclusion, HS increases the incidence of BT both in ascitic cirrhotic and healthy rats. Norfloxacin reduces significantly the incidence of translocation after shock, especially in those cases caused by aerobic gram-negative bacilli.

Animals↗
PubMed1996

Evaluation of the disinfectant effect of Solprogel against human immunodeficiency virus type 1 (HIV-1).

The antiviral activities of sodium dichloroisocyanurate (NaDCC) and a commercial product (Solprogel 2%) against human immunodeficiency virus type 1 (HIV-1) were investigated using a quantitative suspension test method. Solprogel is a compound that contains NaDCC and a biodegradable polymer of acrylic acid. Viral suspensions were prepared containing 3.2 x 10(6) tissue culture infective dose 50 (TCID50) in culture media. Syncytium formation in the MT-2 line and HIV antigen p24 on the supernatant of the cultures were used to determine viral titre. Results indicate that satisfactory disinfection (1000-fold reduction in 5 min) can be achieved using NaDCC and Solprogel at concentrations of 100 and 120 ppm available chlorine, respectively.

Antiviral Agents↗
PubMed1996

Comparison of a biphasic non-radiometric system with Lowenstein-Jensen and Bactec-460 system for recovery of mycobacteria from clinical specimens.

SETTING: The resurgence of tuberculosis and the increase of Mycobacterium avium complex infections have renewed interest in developing more efficient systems for isolation of mycobacteria. The Bactec radiometric method enhances the recovery and shortens the detection time of mycobacteria; however, many clinical laboratories are subject to severe restrictions on the utilization of 14C radiolabelled culture media. OBJECTIVE: To compare the biphasic MB-Check system in the recovery of mycobacteria from clinical specimens with the Bactec-460 system and Lowenstein-Jensen (LJ) medium. DESIGN: The MB-Check was evaluated for routine use in a clinical laboratory by comparing the rates and times for isolation of mycobacteria from 1840 clinical specimens with results obtained using the other systems. The isolated organisms were identified by standard procedures and specific deoxyribonucleic acid (DNA) probes. RESULTS: The rate of recovery of all mycobacteria with the MB-Check system was 84.8%, compared to 87.5% for the Bactec-460 system and only 64.2% on LJ. Of the 147 M. tuberculosis isolates recovered by all methods combined, 92.5% were recovered by MB-Check, 87.1% by Bactec and 79.6% on LJ. Of the 109 isolates of nontuberculous mycobacteria (NTM) recovered by all methods combined, 44% were recovered on LJ, 75% by MB-Check and 88% by Bactec (P < 0.001). A combination of the Bactec and MB-Check systems allowed recovery of 99.2% of isolates. The Bactec system showed a faster detection time than the other two methods. CONCLUSION: The MB-Check and Bactec systems were more efficient than LJ medium for the isolation of both M. tuberculosis and NTM. The performance of the MB-Check system and the ease with which processing, inspection, detection, and isolation can be performed, indicated that the biphasic approach for cultivation of mycobacteria is feasible and practical. The MB-Check system is more suitable than Bactec system for laboratories that have a small number of specimens or in situations where the disposal of radioactive waste is a problem.

Bacteriological Techniques↗