Single-nucleotide polymorphisms in ialB, gltA and rpoB genes of Bartonella bacilliformis isolated from patients in endemic Peruvian regions.

Bartonella bacilliformis is a Gram-negative, aerobic bacterium and the known causal agent of Carrion's disease, still considered a neglected disease. There is limited information about the nucleotide sequences of this bacterium in international databases, and few studies have addressed the genetic diversity of B. bacilliformis. We analyzed a total of 20 isolates of B. bacilliformis from the Peruvian regions of Ancash and Cajamarca. Three genes (ialB, gltA, and rpoB) were sequenced in each isolate and nucleotide sequences retrieved from GenBank (16 B. bacilliformis genomes) were also included in the study. All this information was merged in order to obtain clearer evidence of the phylogenetic relationships of B. bacilliformis. In the phylogenetic analysis conducted with the concatenated markers, four isolates (B.b-1, B. b-3, B. b- 7, B.b-8) from the Ancash region were observed to form a subgroup different from B. bacilliformis type strain KC583, showing dissimilarity levels of 5.96% (ialB), 3.69% (gltA) and 3.04% (rpoB). Our results suggest that B. bacilliformis consists of two different subgroups. Future investigations are needed to establish the taxonomic status of these subgroups.

Polimorfismo en el gen de la catecol o-metil transferasa (COMT) y su asociación con la esquizofrenia en una muestra peruana / Polymorphism in the gen of the catechol O-methyltransferase (COMT) and its association with schizophrenia in a Peruvian sample

La Esquizofrenia es una enfermedad mental crónica y compleja que afecta al 1 por ciento de la población. El gen que codifica a la enzima catecol o-metil transferasa (COMT) es candidato de riesgo porque participa en el catabolismo de la dopamina. El polimorfismo funcional Val/Met (rs4680) en el gen COMT genera actividad enzimática diferencial, es variable en las poblaciones y ha sido asociado a la esquizofrenia. En el Perú, no existen estudios de asociación genética y es necesario implementarlas para la prevención, diagnóstico, pronóstico y farmacogenética de la enfermedad. El objetivo fue establecer la asociación entre el polimorfismo Val/Met en el gen COMT y la esquizofrenia en una muestra peruana. Se ha realizado un estudio tipo casos-controles, previo consentimiento informado, con una muestra de 50 pacientes esquizofrénicos del Hospital Nacional Hermilio Valdizán y 150 personas saludables, sin diagnóstico de la enfermedad, residentes en la ciudad de Lima. El análisis molecular del polimorfismo Val/Met se realizó mediante la técnica PCR-RFLP y confirmado por secuenciamiento automático. En los controles y los pacientes las frecuencias genotípicas fueron similares (Val/Val=40-44 por ciento, Val/Met=46-52 por ciento, Met/Met=8-10 por ciento), y evaluados según el modelo de herencia codominante, no se han encontrado diferencias significativas [p>0.05; Val/Met: OR=0.80 (lC 95 por ciento: 0.41-1.58) y Met/Met: OR=1.14 (lC 95 por ciento: 0.36-3.64)]; la tendencia es similar bajo los modelos de herencia dominante, recesivo, sobredominante y aditivo. Asimismo, las frecuencias alélicas en ambos grupos (Val=66-67 por ciento, Met=33-34 por ciento), no muestran diferencias (p>0.05). Además, el género no interactúa en la asociación con la enfermedad según genotipos Val/Met (p>0.05). Los resultados nos indican que no existe asociación entre el polimorfismo Val/Met en el gen COMT y la susceptibilidad a la esquizofrenia en esta muestra peruana evaluada. En perspectiva, es...

Schizophrenia is a chronic and complex mental disorder that affects 1 per cent of the population. The gene encoding the enzyme catechol o-methyl transferase (COMT) is risk candidate to schizophrenia because of its participation in the dopamine catabolism. The Val/Met polymorphism (rs4680) in the COMT gene generates differential enzymatic activity, it heterogonous in different populations and has been associated with schizophrenia. In Peruvian population, no studies of genetic association with schizophrenia, and is necessary to implement research to assist in the prevention, diagnosis, prognosis and pharmacogenetics of the disease. The aim was to establish the association between of the Val/Met polymorphism in the COMT gene and schizophrenia in a Peruvian sample. We performed a case-control study with a sample of 50 schizophrenic patients from national hospital Hermilio Valdizan and 150 healthy people without disease diagnosis, residents in the city of Lima. The molecular analysis of COMT Val/Met polymorphism was performed by PCR-RFLP and confirmed by automatic sequencing. There were no significant differences in the frequencies of genotypes (Val/Val=40- 44 per cent, Val/Met=46-52 per cent, Met/Met=8-10 per cent) between controls and patients according codominant model [p>0.05; Val/Met: OR=0.80 (IC 95 per cent: 0.41-1.58) and Met/Met: OR=1.14 (IC 95 per cent: 0.36-3.64)]; similar tendencies under dominant, recessive, over dominant, additive models were found. Also, the frequencies of alleles (Val=66-67 per cent, Met=33-34 per cent) in both groups, no showed differences (p>0.05). Furthermore, gender does not interact with the association to disease according to Val/Met genotypes (p>0.05). The results indicate that there is no association between the Val/Met polymorphism in the COMT gene and susceptibility to schizophrenia in this Peruvian sample evaluated. In perspective, it is necessary to study a larger sample, including others Peruvian subpopulations...