Isolation and identification of nontuberculous mycobacteria from specimens of lower respiratory tract of transplanted patients based on the evaluation of 16SrRNA gene

BACKGROUND

Nontuberculous mycobacteria are pervasive microorganisms and are often present as saprophytes in humans, animals, and the environment. Today, these bacteria are known as the most important environmental opportunists and, in the last decades, infections by nontuberculous mycobacteria have multiplied, due to increased immunodeficiency (cancer, transplant recipients, HIV).

STUDY DESIGN

This study aimed to investigate the infections by nontuberculous mycobacteria in transplanted patients.

METHODS

The study was performed on 57 samples from respiratory secretions of transplant recipients taken by standard methods. Nontuberculous mycobacteria were identified by culture method and molecular identities of clinical isolates were investigated by PCR amplification using 16SrRNA gene and sequence analysis and Blast of the sequences. Demographic data were evaluated by Spss software.

RESULTS

The prevalence of nontuberculous mycobacteria in transplant patients was 22.8%, the age of patients was between 23 and 52 years. The most common involvement of nontuberculous mycobacteria in our transplanted individuals were 6 strains of M avium-intracellulare Complex (42.87%), followed by 2 strains of M marinum (14.29%) and 1 strain each (7.14%) of M xenopi, M chelonae, M intracellulare, M kansasii, M simiae. At the conclusion of the tests, one final strain was identified as M tuberculosis (7.14%).

CONCLUSION

The prevalence of nontuberculous mycobacteria indicates their importance in the fate of these patients. The identification of nontuberculous mycobacteria is a neglected part of microbiology laboratories, due to the lack of sufficient facilities and the risk associated with their culture. Therefore developing routine methods for the identification of these infections appears to be critical, especially in hospitals with the transplantation ward.

Going beyond audit and feedback: towards behaviour-based interventions to change physician laboratory test ordering behaviour

Studies indicate there are a variety of contributing factors affecting physician test ordering behaviour. Identifying these behaviours allows development of behaviour-based interventions. Methods Through a pilot study, the list of contributing factors in laboratory tests ordering, and the most ordered tests, were identified, and given to 50 medical students, interns, residents and paediatricians in questionnaire form. The results showed routine tests and peer or supervisor pressure as the most influential factors affecting physician ordering behaviour. An audit and feedback mechanism was selected as an appropriate intervention to improve physician ordering behaviour. The intervention was carried out at two intervals over a three-month period. Findings There was a large reduction in the number of laboratory tests ordered; from 908 before intervention to 389 and 361 after first and second intervention, respectively. There was a significant relationship between audit and feedback and the meaningful reduction of 7 out of 15 laboratory tests including complete blood count (p = 0.002), erythrocyte sedimentation rate (p = 0.01), C-reactive protein (p = 0.01), venous blood gas (p = 0.016), urine analysis (p = 0.005), blood culture (p = 0.045) and stool examination (p = 0.001). Conclusion The audit and feedback intervention, even in short duration, affects physician ordering behaviour. It should be designed in terms of behaviour-based intervention and diagnosis of the contributing factors in physicians' behaviour. Further studies are required to substantiate the effectiveness of such behaviour-based intervention strategies in changing physician behaviour.