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Biomedical subjects

V Ausina

Publications and source records attributed to V Ausina.

At least 109 records · Page 6Linked to original sources
PubMed1992

Pneumonia due to Haemophilus influenzae among mechanically ventilated patients. Incidence, outcome, and risk factors.

Incidence and potential risk factors for pneumonia due to Haemophilus influenzae in adults treated with mechanical ventilation in a medical-surgical ICU were investigated. Diagnosis was established in 91 episodes and H influenzae was isolated in 20 of them. Mean onset of ventilator-associated pneumonia (VAP) due to H influenzae was 10.8 days after intubation. Six patients with H influenzae VAP died in the ICU. Of 13 risk factors for developing VAP due to H influenzae, an absence of prior antibiotic treatment was the only variable which had statistical significance (p < 0.001). In these mechanically ventilated patients, Haemophilus influenzae was a common causative agent for VAP, frequently associated with Gram-positive cocci. Episodes of H influenzae VAP were associated with a lower mortality compared with other etiologies. The epidemiologic and clinical findings indicate that patients without a prior antimicrobial treatment have increased susceptibility to infections of the airway by H influenzae.

Adolescent↗
PubMed1992

Nosocomial pneumonia in critically ill comatose patients: need for a differential therapeutic approach.

The purpose of this prospective clinical study was to determine the incidence, bacteriology and outcome of lower respiratory tract infections developed among 208 consecutive, critically ill comatose patients, hospitalized in a university hospital, medical-surgical intensive care unit, over a three year period. Nosocomial pneumonia developed in 53 (25%) patients after a mean of 8.1 days (range 3-31 days). Furthermore, there were five superinfections, raising the mean incidence to 28%. One patient developed secondary bacteraemia, and another two had septic shock. Fifteen (28%) patients from the pneumonia group died, and six of these deaths were considered to be directly related to nosocomial pneumonia. Identification of the causative agent, using the protected specimen brush technique, was possible in 42 episodes; in 10 (24%) of these cases more than one microorganism was isolated. Gram-positive cocci represented 53% of isolates, and Staphylococcus aureus accounted for 78% of all Gram-positive cocci, being the most frequent microorganism in this population. In conclusion, nosocomial pneumonia is a common complication of critically ill comatose patients. Its characteristic aetiological spectrum in this population should affect antibiotic prescription. Consequently, we suggest including antimicrobial drugs which are active against S. aureus in the empirical regimen until aetiological diagnosis is established.

Anti-Bacterial Agents↗
PubMed1992

[Bacterial pneumonia in the acquired immunodeficiency syndrome].

Sixty five patients with AIDS and clinical and/or radiological evidence of pulmonary infection underwent 78 bronchofibroscopies (BF) with protected brushing and bronchoalveolar washing-out. Out of the 78 BF, bacterial infection was diagnosed in 30 cases and associated opportunistic infection in 12 cases. The 18 cases of exclusively bacterial infection accounted for 23% of the total and most of them were due by H. influenzae and pneumococcus. Just in one patient, the thoracic radiography showed a localized infiltration. Given the high incidence of bacterial infections observed, along with the relevance of myxoid infections (opportunistic and pyogenic bacteria) and the low specificity of the thoracic radiography, bronchoalveolar washing-out and protected brushing in the same BF is a recommended practice.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Protected bronchoalveolar lavage: a new endoscopic method in the diagnosis of bacterial pneumonia].

BACKGROUND: The identification of causative microoganisms in severe pneumonias is a usually difficult problem. Protected brushing (PB) has a good specificity but a limited sensitivity. Conventional bronchoalveolar lavage (BAL-C) has an excellent sensitivity but a doubtful specificity. The investigation of a new technique such as the protected bronchoalveolar lavage (BAL-P) appears as logical, as it should combine the advantages of PB and BAL-C without their drawbacks. METHODS: In 15 patients without bacterial or fungal infections and in 23 with bacterial or fungal pneumonia, quantitative cultures were carried out in the samples obtained with PB, BAL-P and BAL-C. PB and BAL-C were performed with the usual technique. BAL-P was performed through the internal catheter of a telescoped double catheter with reabsorbable distal cap within the fibroscope channel. 40 ml of saline were instillated for the lavage. RESULTS: With BAL-P sensitivity was 95% and specificity 89%. These were, respectively, 55% and 94% with PB, and 95% and 42% with BAL-C. The technique of BAL-P was more complex an longer than that of PB. CONCLUSIONS: If these results are confirmed in further studies, BAL-P might become a method of choice for the bacterial pneumonias where now PB is indicated. However, in patients with hypersecretion or when bronchoscopy should be rapidly carried out, PB is technically more feasible.

Bacterial Infections↗
PubMed1991

Distribution of a novel mycolic acid in species of the genus Mycobacterium.

We found that Mycobacterium porcinum ATCC 33776T (T = type strain) contains a new kind of mycolic acid with a methoxy group at the omega-1 position. This mycolic acid was identified by comparing it with the previously described methoxymycolic acids. The patterns of mycolic acid methyl esters from 418 strains belonging to 44 species of mycobacteria were studied by using thin-layer chromatography. In addition to M. procinum ATCC 33776T, representative strains of M. porcinum, Mycobacterium fortuitum, "Mycobacterium peregrinum," Mycobacterium senegalense, and a recently isolated Mycobacterium sp. contained appreciable amounts of the newly described mycolic acid.

Chromatography, Thin Layer↗
PubMed1991

Evaluation of practical chromatographic procedures for identification of clinical isolates of mycobacteria.

After experimental conditions were established, 366 strains of mycobacteria belonging to 23 different species were studied for fatty acids, secondary alcohols, and mycolic acid cleavage products by capillary gas-liquid chromatography. Additionally, the mycolic acid pattern was studied by thin-layer chromatography. Capillary gas-liquid chromatography allowed direct identification of the following Mycobacterium spp.: M. kansasii, M. marinum, M. szulgai, M. xenopi, M. malmoense, and M. gordonae. The patterns of mycolic acid methyl esters recorded for the test strains of M. chelonae and M. agri may be of value in the identification of these species. Moreover, the combined use of the two chromatographic techniques provided precise identification of the M. tuberculosis complex, M. simiae, M. fallax, M. triviale, and M. chelonae-like organisms. A minimal set of biochemical tests is usually required to obtain identification to the species level when chromatographic procedures alone are not sufficient. Under the reported experimental conditions, thin-layer chromatography and capillary gas-liquid chromatography are rapid and very useful techniques for the identification of mycobacteria.

Alcohols↗
PubMed1991

Incidence, etiology, and outcome of nosocomial pneumonia in mechanically ventilated patients.

This study assessed the incidence, etiology, and consequences of ventilator-associated pneumonia in 1,000 consecutive patients admitted in a medical-surgical intensive care unit (ICU). A total of 264 patients were submitted to mechanical ventilation (MV) for more than 48 hours. Fifty-eight (21.9 percent) patients developed a bacterial pneumonia after a mean of 7.9 days (range, 2 to 40 days) of MV. In addition, they were ten superinfections in nine patients, raising the mean incidence to 25.7 percent. Five patients developed secondary bacteremia, and another five had septic shock. Identification of the causative agent of pneumonia was possible in 47 episodes by means of highly specific techniques (telescoping plugged catheter, blood cultures, and/or necropsy). Thirteen (27.6 percent) of these cases were polymicrobial. The predominant pathogens isolated in the first episode of pneumonia were Gram-negative bacilli (62.6 percent), but a high incidence of Staphylococcus aureus infection (23.2 percent) was detected. Gram-negative bacilli represented 66.6 percent of the total organisms isolated in superinfections. The mortality rate in the pneumonia group was 42 percent; this percentage is similar to mortality rate among MV patients without pneumonia (37 percent). We conclude that nosocomial pneumonia is a frequent complication of MV in the medical-surgical ICU. Ventilator-associated pneumonia does not appear to increase fatality in critically ill patients with a high mortality rate (38 percent); however, it significantly prolongs the length of stay in the ICU for survivors.

Bacteria↗
PubMed1991

[Evaluation of 2 culture systems for the isolation of opportunistic mycobacteria].

The increment of infections produced by opportunist environmental mycobacteria (OEM) raises the question about the appropriateness of the conventional culture methods since they were initially designed to isolate M. tuberculosis. In this study we have comparatively evaluated the yield of a conventional culture (Löwenstein-Jensen) with respect to that of Middlebrook 7H12 (Bactec) in 396 selected samples in which OEM were isolated. Samples with commensal flora were previously subjected to a chemical homogenization-decontamination process with alkaline N-acetyl-cysteine. All cultures were sown with standard inoculates obtained from centrifugate material. The 7H12 culture showed a more rapid detection (mean: 17-18 days) and a greater effectiveness in the isolation of eventually pathogenic mycobacteria than the conventional Löwenstein-Jensen culture. The 7H12/LJ ratio for the species with high clinical relevance was: 1.3 for M. kansasii, 1.0 for M. marinum, 1.8 for M. scrofulaceum, 1.3 for M. xenopi, 1.5 for M. avium-intracellulare, 0.5 for M. chelonae, and 2.0 for M. fortuitum.

Bacteriological Techniques↗
PubMed1990

A novel mycolic acid in a Mycobacterium sp. from the environment.

A fast-growing, non-photochromogenic mycobacterium isolated from the environment exhibited, on thin-layer chromatograms, a characteristic pattern of mycolates composed of unsaturated mycolates and also an unknown more polar component. Spectroscopic analysis and chemical degradation showed that this latter component was a novel mycolic acid containing a methoxy group at the omega-1 position (instead of omega-17 and omega-18 in known methoxymycolates), and two double bonds in the long mero aldehyde chain (instead of one as in known mycolates with additional oxygenated groups).

Magnetic Resonance Spectroscopy↗
PubMed1990

[Pulmonary disease caused by opportunistic environmental mycobacteria. Review of 35 cases].

The clinical characteristics, radiologic findings, and therapeutic response in 35 cases of pulmonary disease induced by opportunistic environmental mycobacteria collected during a period of 4 years are reported. These cases included 21 infections by Mycobacterium kansasii, 10 by M. xenopi, and 4 by M. avium. The cases reported constituted the 6% of all mycobacterial infections of the lung observed in our institution. The mean age of the patients was 56 years and 83% of them were male. The presence of previous pulmonary involvement was rather frequent, specially the existence of chronic limitation of the air flow (CLAF) (91%) and previous tuberculosis (29%). The clinical symptoms were almost nonspecific and they could frequently be misinterpreted as an intercurrent infection in cases of CLAF. The radiologic findings could not be distinguished from an infection by M. tuberculosis. The clinical course with pharmacologic first line therapy (93% of cases) was satisfactory in 28 patients in whom follow-up controls are available.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Risk factors for Staphylococcus aureus nosocomial pneumonia in critically ill patients.

Staphylococcus aureus nosocomial pneumonia has become an important infection not only because of an apparently increasing incidence but also because of its high mortality rate. A total of 50 episodes of nosocomial pneumonia in critically ill patients in which etiologic diagnosis was well established were prospectively followed in a medical-surgical intensive care unit (ICU). S. aureus was isolated in a total of 13 episodes. In the univariate analysis the variables significantly associated with S. aureus nosocomial pneumonia were below 25 yr of age, coma, nonuse of corticosteroids, and antecedent trauma. A step-forward logistic regression analysis defined only coma as significantly influencing the risk of developing S. aureus nosocomial pneumonia. We suggest that antimicrobial drugs active against S. aureus must be included in the initial empirical antimicrobial regimen for treating nosocomial pneumonia in patients with coma. The identification of factors influencing the etiology and the possibility of earlier effective antimicrobial treatment may represent a further step in the control of nosocomial pneumonia in critically ill patients by improving its prognosis.

Adult↗
PubMed1990

[Primary and initial bacterial resistances in tuberculosis patients at a general hospital, 1983-1987].

From july 1982 to december 1987 we prospectively evaluated the primary resistance (PR) of 248 strains of M. tuberculosis isolated from patients with several clinical forms of tuberculosis. The results were compared with those of a similar study carried out between 1978-1982. PR persisted relatively stable with time, although it showed a trend towards reduction. Isoniazide resistance (4.8%) still has a leading epidemiological interest. The 89% of strains showed isolated resistance to a single drug. Only two strains had associated resistance to INH and SM. Strains with PR to RIF, ETB or PZA were not detected. Of the 248 evaluated strains, 32 were isolated from intravenous drug abusers with AIDS. Only one of these strains had a low level (0.2 mg/l) PR to INH. At last two of these drug abusers developed acquired resistance to INH and ETB-RIF, respectively. Considering the difficulty to control chemotherapy in this group of patients, our finding has a considerable epidemiological interest.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Capillary gas chromatographic analysis of mycolic acid cleavage products, cellular fatty acids, and alcohols of Mycobacterium xenopi.

The fatty acids, alcohols, and mycolic acids of 26 strains of Mycobacterium xenopi were studied by capillary gas chromatography and thin-layer chromatography. All strains contained alpha-, keto-, and omega-carboxymycolates. The primary mycolic acid cleavage product was hexacosanoic acid. The fatty acid patterns and, especially, the presence of 2-docosanol are characteristic markers of M. xenopi.

Alcohols↗
PubMed1988

Prospective study on the etiology of community-acquired pneumonia in children and adults in Spain.

The cause of primary pneumonia was diagnosed in 157 of 198 children and 165 of 207 adults seen as inpatients or outpatients in a 12-month period. In children Mycoplasma pneumoniae and pneumococcus were identified in 79 and 29 cases respectively. Twenty-nine of 53 cases of viral infection in children were caused by respiratory syncytial virus, two-thirds of the cases occurring in children under three years of age. No children died of pneumonia. In adults pneumococcus was the most common pathogen, accounting for 81 cases. The overall mortality in adults was 7.7%. A high mortality was found in patients with Haemophilus influenzae and other gram-negative bacilli infections, and in elderly patients with pneumococcal pneumonia. Coagglutination was more sensitive than counterimmunoelectrophoresis for the detection of pneumococcal antigen in respiratory samples (p less than 0.001). Counterimmunoelectrophoresis was the only useful technique for detection of pneumococcal antigen in urine specimens, concentration, overnight storage at 4 degrees C and specific staining significantly increasing positivity (p less than 0.001).

Adult↗