Background & Objective: Tuberculosis is more prevalent in developing countries and death from tuberculosis meningitis is strongly associated with delays in diagnosis and treatment. Polymerase chain reaction (PCR) has been incorporated as a diagnostic tool for the diagnosis of tuberculosis. The rapid results and greater sensitivity compared to traditional microbiological methods makes PCR a suitable technique in tuberculosis, especially in tuberculosis meningitis, when diagnosis is difficult or when rapid diagnosis is needed. However, the possibility of false positive and false negative results must be considered. The aim of this study was to compare the conventional bacteriology (culture Ziehl- Neelsen staining) with polymerase chain reaction (PCR) technique for rapid diagnosis of tuberculosis meningitis.

 Methods: This study included 25 clinically diagnosed patients that were suspected to have tuberculosis meningitis and 10 other bacterial or viral meningitis patients were investigated. DNA was extracted from CSF and the NESTED PCR using specific primers were done.

 Results: In 25 samples, Mycobacterium tuberculosis DNA was detected in 9 (36%) by PCR, 2(8%) and 1(4%) with culture and direct smear was obtained, respectively. whereas no DNA bands were detected in patient with the other 10 meningitis. The entire procedure was repeated and the same result was obtained.

 Conclusion: The findings of this study indicated that PCR is a powerful method for rapid and sensitive diagnosis of tuberculosis meningitis. In a way that it decreases obtaining the results from several weeks in bacteriological methods to one to two days, especially in smear negative patients. This is very important in tuberculosis meningitis because it is a medical urgency and needs rapid diagnosis and early treatment.

  Background & Objectives: E. coli is an opportunistic and pathogenic bacterium in human. It is a fecal contamination indicator of the water. The aim of this study is to investigate the efficiency of ultra violet radiation in disinfection of E. coli in aquatic environments in a batch system.

  Methods: At first, reactor was designed and made. The effects of pH, exposure time and initial inoculum were studied. Kinetic parameters were obtained by application of zero, first and second - order equations .

  Results: The result showed that removal efficiency decreased with increase of initial inoculum�and the kinetics of disinfection was described by first-order model. The result also showed that removal efficiency augmented with increasing exposure time and pH .

  Conclusion: The results of this study shows that ultra violet radiation can be used as an effective disinfection method for E. coli in aquatic environments.