Carlos Fuertes Muñoz

High prevalence of subtype 4 among isolates of Blastocystis hominis from symptomatic patients of a health district of Valencia (Spain)

In order to know the genetic diversity of Blastocystis hominis from a health district of Valencia (Spain) 51 clinical isolates from symptomatic patients,31 axenic and 20 monoxenic, were ribotyped by analysing the restriction fragment length polymorphism (RFLP) of amplicons obtained by polymerase chain reaction (PCR) of small-subunit of ribosomal DNA genes (SSU-rDNA). For this purpose, DNA was subjected to two independent PCR (RD3-RD5, F1-R1) and to three independent treatments with restrictases (AluI, HinfI and RsaI). The digested DNA was separated electrophoretically, the isolates were clustered into ribotypes (ribodemes, RD3-RD5; subgroups, F1-R1) according to their profiles and the results were translated into genetic subtypes (ST) proposed by a consensus terminology. The results show that the isolates studied are an heterogeneous population and that both PCR-RFLP SSU-rDNA protocols have a similar discriminative power, since it allowed the ribotyping of all isolates and their clustering into four demes: ribodemes 1, 3 and 3-r and 6, which include isolates belonging to subgroup III, IV, V and V-r, respectively; which were assigned to ST1 (2%), ST2 (3.9%) and ST4 (94.1%). The most common of which is a zoonotic subtype (Blastocystis ratti) which includes, according to recent studies, non-pathogenic and pathogenic variants.

Search of Chemical Scaffolds for Novel Antituberculosis Agents

A method to identify chemical scaffolds potentially active against Mycobacterium tuberculosis is presented. The molecular features of a set of structurally heterogeneous antituberculosis drugs were coded by means of structural invariants. Three techniques were used to obtain equations able to model the antituberculosis activity: linear discriminant analysis, multilinear regression, and shrinkage estimation–ridge regression. The model obtained was statistically validated through leave-n-out test, and an external set and was applied to a database for the search of new active agents. The selected compounds were assayed in vitro, and among those identified as active stand reserpine, N,N,N′,N′-tetrakis-(2-pyridylmethyl)-ethylenediamine (TPEN), trifluoperazine, pentamidine, and 2-methyl-4,6-dinitro-phenol (DNOC). They show activity comparable to or superior to ethambutol, used in combination with other drugs for the prevention and treatment of Mycobacterium avium complex and drug-resistant tuberculosis.