Research and laboratory

Research

The research activity of Fontilles is developed in four lines of work, focused on the field of Molecular Biology through the detection and analysis of DNA M. leprae.

Sensitive studies

Sensitivity studies are carried out, comparing different techniques of biology molecular and conventional techniques, for the detection and diagnosis of Mycobacterium leprae in different types of samples. These studies are used especially in cases with very few bacilli (paucibacillary leprosy), because the centennial Ziehl-Neelsen stain, due to its lack of sensitivity, does not allow the microscopic visualization of bacilli.

Transferability studies

Studies of community and intradomestic population transmissibility with molecular detection of the bacillus at nasal mucosa level. These studies are performed in endemic areas where annual incidences are high. The study of the mechanisms of transmission of the disease in the first or second order contacts, starting from the index case.

Molecular genotyping studies

Molecular genotyping studies at different levels of the bacillus genome, in order to determine their origin and to establish patterns of transmission in the affected populations, characterizing the different positive isolates of M. leprae.

Studies for the detection of resistance

These are molecular studies for the detection of bacillus resistance against different therapeutic targets. Currently this line of research focuses on observing the possible genetic susceptibility of patients diagnosed in Fontilles, as well as the procedure of our international projects and determining the risk of possible relapses or therapeutic failures in our work envirement.

Laboratory

Since 1922, Fontilles has a laboratory where, in addition to serving resident and ambulatory patients, Fontilles had developed its research. The laboratory has been equipped with the latest technologies of every moment, and it covers the areas of hematology, biochemistry, immunology and microbiology.

Conventional diagnosis

Ziehl-Neelsen stain (smear microscopy). The differential stain allows the detection of acid-fast bacilli (BAAR) in the sample. Generally, in the case of the diagnosis of M. leprae this sample will be a lymph or nasal mucosa smear that will be observed at the optical microscope at 1,000 magnifications.

This technique allows, on the one hand, to quantify the bacterial load (bacteriological index) and on the other hand, to observe the microbial viability (morphological index), very useful both in the diagnosis and in the follow-up of the patient.

The drawback of this technique is that, due to its lack of sensitivity, less than 100 bacilli cannot be observed in the sample.

Molecular diagnosis

The use of molecular techniques to confirm the diagnosis ofMycobacterium leprae is very useful, especially in cases of paucibacillary leprosy where the smear microscopy is negative.

With the molecular biology techniques (PCR) we managed to improve the sensitivity until achieving the DNA detection of a single bacillus in the sample. This technique allows the analysis of a great variety of biological samples, although generally the sample of choice is usually a skin biopsy (preserved in 70% ethanol).

Apart from PCR for diagnosis, Fontilles has techniques for the analysis of resistance to antibiotics (rifampicin, dapsone and ofloxacin) according to the guidelines established by the WHO.