Search PubMed⌕ Search

Biomedical subjects

V Ausina

Publications and source records attributed to V Ausina.

At least 91 records · Page 5Linked to original sources

Detection of Legionella pneumophila serogroup 1 antigen in nonconcentrated urine and urine concentrated by selective ultrafiltration.

We evaluated a commercially available radioimmunoassay technique for detecting the soluble antigen of Legionella pneumophila serogroup 1 using concentrated and nonconcentrated urine. Concentration was achieved by selective ultrafiltration. The sensitivity of the technique was 60.9% for nonconcentrated urine and 80.4% for concentrated samples, with 100% specificity in both cases.

Antigens, Bacterial↗

Prospective study of drug-resistant tuberculosis in a Spanish urban population including patients at risk for HIV infection.

From January 1988 to October 1992, the primary resistance to first-line antituberculous drugs in 501 tuberculous patients was evaluated prospectively. Three-hundred and seventeen patients were HIV-negative and 184 were HIV-positive; these patients had several different clinical forms of tuberculosis. Moreover, the acquired resistance to antituberculous drugs was studied in 295 non-AIDS patients and in 42 AIDS patients with evidence of antecedent tuberculosis treatment. The data indicated that during these five years there was no consistent and clear-cut trend toward greater frequency of primary drug resistance to any of the first-line antituberculous drugs. Primary drug resistance in HIV-positive patients (7.1%) did not differ significantly (p > 0.05) from that found in HIV-negative patients (8.2%). Among HIV-positive patients, the acquired drug resistance pattern was similar to that detected in HIV-negative patients although the frequency of resistance in the former (69%) was significantly higher (p < 0.01). During the study, resistance to isoniazid was almost constant in the acquired-resistance cases and was frequently associated with resistance to other drugs. Furthermore, the acquired resistance to isoniazid was often of a higher level (1 to 10 mg/l) than the primary resistance (0.2 mg/l), and those strains were usually catalase and peroxidase negative.

AIDS-Related Opportunistic Infections↗

Treatment of pulmonary disease caused by Mycobacterium kansasii: results of 18 vs 12 months' chemotherapy.

SETTING: Chest Clinic, Sant Pau Hospital, Barcelona, Spain. OBJECTIVE: To assess the therapeutic response of pulmonary disease due to Mycobacterium kansasii to 12 and 18 months of chemotherapy. DESIGN: 28 patients with criteria of pulmonary disease caused by M. kansasii not associated with HIV-infection were identified in our department in the period 1985-91 (24 male, 4 female, mean age 56 +/- 12 years). 14 patients were treated with rifampicin-isoniazid-ethambutol daily for 12 months (ethambutol only for the first 6 months), and 14 with the same regimen for 18 months. The follow-up after treatment was 12-30 months. RESULTS: All patients showed improvement of radiographic manifestation of disease and sputum conversion (mean time: 4.5 +/- 2 months). The adverse drug effects were minimal. No failures were detected, and only one patient (3.5%), in the group of 12-month chemotherapy, relapsed after finishing the treatment. CONCLUSIONS: Our findings suggest that pulmonary disease due to M. kansasii has an effective response to 12-month chemotherapy regimen and that it is not necessary to prolong the administration of ethambutol for more than 6 months.

Adult↗

Inhibitory effect of sodium dodecyl sulfate in detection of Mycobacterium tuberculosis by amplification of rRNA.

The concentrations of sodium dodecyl (lauryl) sulfate (SDS) found in the sediments of the respiratory samples pretreated with SDS-NaOH varied between 3.36 and 12.42 mg/ml. These concentrations of SDS were higher than the level considered critical (> or = 0.16 mg/ml) to obtain negative results with the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test. Extensive washing, after neutralization of sediment, is sufficient to remove all traces of detergent which interfere with the enzymes used by the Mycobacterium Tuberculosis Direct Test assay.

Bronchoalveolar Lavage Fluid↗

Bacterial infection in chronic obstructive pulmonary disease. A study of stable and exacerbated outpatients using the protected specimen brush.

The lower airways of asymptomatic chronic obstructive pulmonary disease (COPD) patients can be colonized by bacteria, mainly Haemophilus influenza, Streptococcus pneumoniae, and Moraxella catarrhalis. However, the role of lower airway bacteria in stable and exacerbated COPD has not been well defined. To determine the importance of lower airway bacterial infection in COPD we studied 40 outpatients with stable COPD (Group A: age 61.1 +/- 9.9 yr; [mean +/- SD]; FEV1/FVC 51.7 +/- 12.5) and 29 outpatients with exacerbated COPD (Group B: age 63.4, SD 9.0 yr; FEV1/FVC 52.0, SD 9.6), using the protected specimen brush (PSB) for microbiology sampling. Group A consisted of outpatients with stable COPD having normal or near-normal chest X-rays, with clinical indications for performing fiber-bronchoscopy (pulmonary nodule, remote hemoptysis); Group B consisted of patients with exacerbated COPD who voluntarily accepted lower airway microbiology sampling. To avoid contamination by upper airway flora the PSB was used for bacterial sampling in all the cases and concentrations > or = 1,000 colony-forming units/milliliter (CFU/ml) were considered positive. Results were as follows: Group A: Lung function data in outpatients with stable COPD were lower than the reference values for this population (FVC 2.97 +/- 1.02 L, FVC% 71.4 +/- 22.4, FEV1 1.59 +/- 0.79 L, FEV1% 51.2 +/- 23.0). Positive PSB cultures were obtained in 10 of 40 cases (25%), mainly of H. influenzae and S. pneumoniae. Two of 40 cases had positive cultures at concentrations > or = 10,000 CFU/ml (5.0%).(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Infections↗

Risk factors for infection by Pseudomonas aeruginosa in patients with ventilator-associated pneumonia.

OBJECTIVE: to investigate the epidemiology of infection by Pseudomonas aeruginosa in patients with ventilator-associated pneumonia (VAP). DESIGN: prospective clinical study. SETTING: a medical-surgical ICU in a university hospital. PATIENTS: we followed-up 568 mechanically ventilated patients and 83 episodes of VAP with etiologic diagnosis in 72 patients were retained for analysis. RESULTS: Ps. aeruginosa was isolated in 22 (26.5%) episodes in 18 patients. Of these episodes 7 were directly responsible for death. Using logistic regression analysis, the risk of VAP due to Ps. aeruginosa was increased in patients with chronic obstructive pulmonary disease (relative risk (RR) = 29.9, 95% confidence interval (CI) = 4.86-184.53), a mechanical ventilation period longer than 8 days (RR = 8.1, 95% CI = 1.01-65.40) and prior use of antibiotics (RR = 5.5, 95% CI = 0.88-35.01). CONCLUSIONS: patients with VAP and these factors have a greater risk of infection by Ps. aeruginosa and empirical therapy for these episodes should include anti-pseudomonal activity until etiologic diagnosis is established.

Adult↗

[Experimental study of bronchofibroscope disinfection].

BACKGROUND: Fibrobronchoscopes (FB) require high level disinfection following each procedure to prevent possible infectious complications. The aim of the present study was to evaluate three methods of disinfection of the FB: a) aspiration with a solution of iodine povidone (IP); b) immersion in fenolate glutaraldehyde (FG) diluted at 1:16, and c) aspiration of IP solution followed by immersion in FG. Cleaning of the FB with soap and water was also studied. METHODS: The FB was contaminated with artificial samples (sterilized respiratory secretions mixed with a suspension of a microorganism at a concentration of 10(8)-10(9) UFC/ml) and was later washed with soap and water and disinfected with one of the 3 above mentioned methods. Samples were taken following contamination, cleaning, the aspiration with IP and at 5, 10, 15, 20 and 30 minutes in FG. The c/u/ml were counted. Disinfection was considered as a failure with > or = 1 c/u/ml at the end of each experience. This test was performed 97 times: 37 with Mycobacterium tuberculosis, 17 with Serratia marcescens, 17 with Pseudomonas aeruginosa, 13 with Staphylococcus aureus, and 13 with Candida albicans. RESULTS: Cleaning with soap and water eliminated a mean of 99.9% of the microorganisms. IP failed to disinfect all the 5 microorganisms while FG and the association of IP and FG failed against S. marcescens and P. aeruginosa. The time of immersion in FG required for complete disinfection range from 5 to 20 minutes although in most cases only 5 to 10 minutes were needed. CONCLUSIONS: The meticulous cleaning of the FB is essential for correct disinfection. Iodine povidone does not guarantee high level disinfection of the device while fenolate glutaraldehyde and iodine povidone plus fenolate glutaraldehyde may fail versus S. marcescens and P. aeruginosa.

Bronchoscopes↗

A three-year study of severe community-acquired pneumonia with emphasis on outcome.

Fifty-eight consecutive patients with severe community-acquired pneumonia were studied prospectively during a three-year period. The group included 44 men and 14 women (mean age: 45.0 +/- 15.7 years). The cause of pneumonia was diagnosed in 35 (60.3 percent) cases, and the most common pathogens were Streptococcus pneumoniae (37.1 percent), Legionella pneumophila (22.8 percent) and Gram-negative bacilli (11.4 percent). The fact that Mycobacterium tuberculosis was present in four (11.4 percent) patients and Pneumocystis carinii in three (8.5 percent) is worthy of note. The overall death rate was 22.4 percent. More than 50 percent of deaths occurred within the first five days and were caused by septic shock, hemoptysis (tuberculosis) or hypoxia. However, hypoxia remains the main fatal complication and all late-occurring deaths (> 5 days) observed were due to this cause. These data could be important in planning strategies and protocols to improve prognosis.

Adult↗

Impact of previous antimicrobial therapy on the etiology and outcome of ventilator-associated pneumonia.

OBJECTIVE: To define the influence of prior antibiotic use on the etiology and mortality of ventilator-associated pneumonia (VAP). SETTING: A university hospital medical-surgical ICU. DESIGN: Prospective clinical study. METHODS: Over a 35-month period, we prospectively studied 129 consecutive episodes of VAP. Etiologic diagnosis was established using a protected specimen brush and quantitative culture techniques. We examined prognostic factors by univariate and multivariate analyses using a statistical software package (SPSS). RESULTS: The rate of VAP caused by Gram-positive cocci or Haemophilus influenzae was statistically lower (p < 0.05) in the patients who had received antibiotics previously, while the rate of VAP caused by Pseudomonas aeruginosa was statistically higher (p < 0.01). Patients died of causes directly related to the infection in 18 (14.0 percent) episodes, P aeruginosa being isolated in 9 of these fatal cases. Indeed, we found that 27.7 percent (15/54) of patients who had received prior antimicrobial therapy before the onset of pneumonia died, compared with only 4.0 percent (3/75) of those who did not. In the univariate analysis, the variables significantly associated with attributable mortality were age older than 45 years, use of corticosteroids, presence of shock, hospital day of VAP over 9, antecedent COPD, and a prior antibiotic use. A step-forward logistic regression analysis defined only prior antibiotic use (p < 0.0001, OR = 9.2) as significantly influencing the risk of death from VAP. The same result was obtained when severity was included in the model. However, prior antibiotic use entirely dropped out as a significant risk factor when the etiologic agent was included in the regression equation. CONCLUSIONS: Distribution of infecting microorganisms responsible for VAP differs in patients who received prior antimicrobial therapy, and this factor determines a higher mortality rate. We suggest a restrictive antibiotic policy in mechanically ventilated patients with the purpose of reducing the risk of death from VAP.

Anti-Bacterial Agents↗

Human tuberculosis due to Mycobacterium bovis: report of 10 cases.

During the period 1986-1990, 10 cases of human disease caused by Mycobacterium bovis were diagnosed in our hospital. The incidence, in relation to the cases of disease from Mycobacterium tuberculosis diagnosed in the same period, was 0.9%. The patients had an average age of 32 years (range 5-68 years). Pulmonary disease was observed in 5 patients (50%), lymphadenitis in 2, pleural effusion in 2 and peritoneal in 1. The most significant of the epidemiological features was that 2 patients were veterinary students. There was 1 death from ovarian neoplasia with abdominal dissemination. The other cases responded favourably to treatment with standard chemotherapy of 6-12 months achieving cure, without relapse, of all the patients.

Adolescent↗

Mycobacterium alvei sp. nov.

A new species of rapidly growing, nonphotochromogenic mycobacteria, Mycobacterium alvei, is described. The inclusion of this organism in the genus Mycobacterium is based on its acid fastness, its mycolate pattern, and its G + C content. A study of six strains showed that they form a homogeneous group with an internal phenotypic similarity value of 97 +/- 2.22%. DNA relatedness studies showed that the six M. alvei strains which we studied form a single DNA hybridization group which is less than 49% related to 14 other species of the genus Mycobacterium; the deltaTm values determined for the strains which exhibited higher levels of DNA homology were all greater than 7.9 degrees C. A lipid analysis showed that tuberculostearic acid was present. Docosanoic and tetracosanoic acid methyl esters were detected as mycolic acid cleavage products. All six isolates which we tested contained alpha-mycolic acids and relatively large amounts of a new kind of mycolic acid containing a methoxy group of omega-1 position, a characteristic that has not been described previously in mycobacteria. Strain CR-21 is the type strain; a culture of this strain has been deposited in the Collection Nationale de Cultures de Microorganismes de l'Institut Pasteur, Paris, France, as strain CIP 103464.

Base Composition↗

Nosocomial respiratory tract infections in multiple trauma patients. Influence of level of consciousness with implications for therapy.

A prospective study of 161 multiple trauma patients was carried out to determine the incidence, the causative agents, and the outcome of nosocomial respiratory tract infections in this highly selected population. Thirty-eight (23.6 percent) patients developed a nosocomial pneumonia (NP). In addition, there were four superinfections in three patients, representing an incidence of 26 percent (42 of 161). Incidence of NP was significantly greater among comatose patients (42.2 vs 13.3 percent, p less than 0.05). Furthermore, purulent tracheobronchitis was diagnosed in six patients. The causative agent of NP was identified in 36 (85.7 percent) episodes by means of fiberoptic bronchoscopies with protected specimen brush sampling. Staphylococcus aureus (55.8 percent) was the predominant pathogen isolated in multiple trauma patients in coma (Glasgow coma score [GCS] below 9 during a period greater than 24 h), while aerobic Gram-negative bacilli were responsible for the majority of cases in the remaining population studied. The overall mortality rate was 19.8 percent, but only five deaths were related to NP. We conclude that nosocomial respiratory tract infections are a frequent problem in multiple trauma patients, especially in those with GCS below 9, although this complication is associated with a relatively low mortality. Among patients with GCS below 9, S aureus was a frequent finding; consequently, antimicrobial therapy in this population needs to be different than that for the remaining multiple trauma patients with NP.

Bacteria↗