[ identification of nocardia in BAL specimens of bronchoscopic patients by using classical and molecular methods]

Nocardiosis is a rare and potentially life-threatening infection caused by several species of the Nocardia genus. The objective of this study was to develop and evaluate a rapid and new method to clinically identify relevant Nocardia species. Rapid and accurate diagnosis of Nocardia species is essential for the treatment of severe infections and prevention of cerebral abscess. One hundred and eighty patients, 103 [57.22%] male and 77 [42.78%] female, with severe symptomatic pulmonary infection were studied in the course of a 12-month period in Dr. Shariati Teaching Hospital affiliated to Tehran University of Medical Sciences in 2010. The specimens were cultured and identified using microbiological and biochemical tests. Polymerase chain reaction [PCR] was used to directly identify the organism in the broncoalveolar lavage samples collected from the patients. NG1 and NG2 primers were used to amplify a Nocardia genus-specific 598-bp fragment of 16S rRNA. Nineteen samples [10.56%] were positive with PCR and 5 samples [2.78%] with conventional methods. All samples with positive cultures were also positive by PCR. The results of this study showed that PCR has a high sensitivity and accuracy for the detection of Nocardia compared with culture and biochemical tests. Considering the rapidity, precision, high sensitivity and specificity of molecular techniques, use of these techniques is suggested in conjunction with conventional methods for the detection of Nocardia phenotypes in clinical laboratories and research centers

Production and purification of a protease from an alkalophilic Bacillus sp. 2-5 strain isolated from soil

This research has focused on isolation and characterization of a strain of Bacillus sp. from alkaline soil, which was able to produce extracellular alkaline protease at pHs ranging from 8 to 11 and temperatures of 20 to 50§C. Also the impact of different carbon and nitrogen sources were investigated. The yield and fold of enzyme purification was 24% and 50 times, respectively. Molecular weight of purified enzyme was measured by SDS-PAGE as 24.7 kDa. The alkaline protease produced by Bacillus sp. 2 - 5 showed the most caseinolytic activity [without any gelatinolytic activity] at pH>10