A simple and low cost tetra-primer ARMS-PCR method for detection triazole-resistant Aspergillus fumigatus.

The mutation at codon L98 accompanied by a tandem repeat of 34 base pairs (TR34/L98H) in the 5´upstream region of cyp51A is the principal mechanism of triazole resistance of Aspergillus fumigatus. We aimed to evaluate a simple and low-cost tetra-primer amplification refractory mutation system (ARMS)-PCR technique for detection of TR34/L98H mutations in the cyp51A gene of azole-resistant A. fumigatus. The tetra-primer ARMS-PCR assay optimized by four primers in one reaction consists of external primers for detection of tandem repeats in the promoter region and internal primers for detection of a point mutation in codon 98 (L98H) in the cyp51A gene of azole-resistant A. fumigatus. The specificity of TR34/L98H mutation detection was assessed by testing 36 clinical and environmental A. fumigatus strains. The tetra-primer ARMS-PCR assay from A. fumigatus, containing wild-type sequence (T allele) and L98H mutation at cyp51A (A allele), yielded two DNA fragments of 908 bp and 740 bp and two of 942 bp and 212 bp, respectively. None of the A. fumigatus isolates without the TR34/L98H mutation yielded false-positive results. The ARMS-PCR assay was 100% concordant with DNA sequencing results. Prevalence and screening of the TR34/L98H mutation in the cyp51A gene in A. fumigatus isolates may now be determined by a fast, low-cost, and simple method in resource-poor settings.

Framework for continuous assessment and improvement of occupational health and safety issues in construction companies.

BACKGROUND: Construction industry is among the most hazardous industries, and needs a comprehensive and simple-to-administer tool to continuously assess and promote its health and safety performance. METHODS: Through the study of various standard systems (mainly Health, Safety, and Environment Management System; Occupational Health and Safety Assessment Series 180001; and British Standard, occupational health and safety management systems-Guide 8800), seven main elements were determined for the desired framework, and then, by reviewing literature, factors affecting these main elements were determined. The relative importance of each element and its related factors was calculated at organizational and project levels. The provided framework was then implemented in three construction companies, and results were compared together. RESULTS: THE RESULTS OF THE STUDY SHOW THAT THE RELATIVE IMPORTANCE OF THE MAIN ELEMENTS AND THEIR RELATED FACTORS DIFFER BETWEEN ORGANIZATIONAL AND PROJECT LEVELS: leadership and commitment are the most important elements at the organization level, whereas risk assessment and management are most important at the project level. CONCLUSION: The present study demonstrated that the framework is easy to administer, and by interpreting the results, the main factors leading to the present condition of companies can be determined.