Molecular characterization of environmental non-Tuberculous mycobacteria using PCR- RFLP analysis of 441 Bp heat shock protein 65 fragments

Non- Tuberculous Mycobacteria are environmental opportunistic pathogens that can be found in various terrestrial and aquatic habitats. There are an epidemiological links between species isolated in tap water and those isolated from patients. hsp65 gene has more variability in its sequences, compared to the some more conserved genes in NTM, for identification of mycobacteria to species level. In this study, the prevalence of NTM in Isfahan City water samples was determined using culture, biochemical tests and PCR-RFLP analyses of hsp65 gene. Eighty-five water samples were collected and cultured. The mycobacterial isolates were identified by conventional biochemical tests. A 441 bp fragment of hsp65 genes was amplified and digested by two restriction enzymes, BstEII and HaeII. Digested products were analyzed using polyacrilamid gel electrophoresis [PAGE]. 25.9% of the water samples contained different species of NTM. Dominant isolates were M. fortuitum [26.7%], M. chelonae like organism [13.3%] and M. mucogenicum [13.3%]. Nineteen isolates of Mycobacteria were differentiated using hsp65 genes PCR-RFLP. Three isolates could not be identified at the species level because their RFLP patterns were different from other known PCR-RFLP profiles. There were different hsp65 gene PCR-RFLP profiles produced by digestion with BstEII and HaeIII. This study showed that PCR-RFLP of hsp65 gene in mycobacteria is more reliable method for identification of NTM at the specie level than conventional phenotypic methods [P<0.05]. In comparing of RFLP patterns of this study to other investigation, some minor differences were negligible

Assessment of urine iodine in school children from urban and rural areas of Tehran in 2001

Following the national survey for Iodine Deficiency Disorder [IDD] in 1989 which manifested endemic goiter in Iran, the iodination program was implemented. By 1998, Iran has managed to become an IDD-free country. This study is a part of continuous assessment to monitor the effectiveness of this program. The prevalence of iodine deficiency was studied by assessment of urine iodine concentration among a random sample of schoolchildren, in the South Tehran. The extent of salt iodination in the public was assessed meanwhile. Most cases [52.19%] showed a urine iodine concentration between 10-30 micro g/dl. As well, 5.85% of pupils had mild iodine deficiency according to world standards, 1.45% of pupils showed moderate and none had severe IDD. Examination of consumed salt in public areas showed 98.8% iodination. Total mean iodine excretion was obviously above the state survey in 1996. The risk of exceeding the allowed limits [<30 micro g/dl] should be attentively studied