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Resumen Antecedentes: Chlamydia trachomatis es la bacteria que se detecta con mayor frecuencia en las infecciones de transmisión sexual. Se han identificado 20 genotipos de C. trachomatis mediante el gen ompA y varias genovariantes mediante el análisis de polimorfismo de un solo nucleótido (SNP). En México, el genotipo F es el más frecuente. Objetivo: Identificar la existencia de subtipos del genotipo F. Método: Se analizaron siete cepas del genotipo F de C. trachomatis aisladas en 2011, mediante secuenciación de nucleótidos y mapeo con enzimas de restricción. Resultados: El análisis de SNP mostró dos cepas con el mismo SNP en el nucleótido 288 (C288T), mientras que con enzimas de restricción se identificó una variante con diferente RFLP (polimorfismo de la longitud de fragmentos de restricción) cuando se tratan con la mezcla de enzimas HinfI y TaqI. Conclusión: En México se encuentran dos subtipos del genotipo F y solo las enzimas de restricción HinfI y TaqI pueden identificar la existencia de uno de estos genotipos F.
Abstract Background: Chlamydia trachomatis is the most frequently identified bacterium in sexually transmitted infections. Twenty C. trachomatis genotypes have been determined using the ompA gene and several genovariants by single nucleotide polymorphism (SNP) analysis. In Mexico, the F genotype is the most frequent. Objective: To identify subtypes of the F genotype. Method: Seven C. trachomatis genotype F strains isolated in 2011 were analyzed by nucleotide sequencing and restriction enzyme mapping. Results: SNP analysis showed two strains with the same SNP at nucleotide 288 (C288T), while with res-triction enzymes, a variant with different RFLP (restriction fragment length polymorphism) was identified when treated with the mixture of HinfI and TaqI enzymes. Conclusion: In Mexico, there are two subtypes of F, and only with restriction enzymes HinfI and TaqI can identify one of the genovariants of the F genotype.
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Objective To analyze genetic characterization of the small hydrophobic and hemagglutinin-neuraminidase genes of mumps virus(MuV)isolated in Yunnan province,China from 2007 to 2009.Methods Fourteen MuV strains were isolated in Yunnan,China from 2007 to 2009.Using RT-PCR,the SH gene fragments contained 316 nucleotides in all strains and HN gene of six strains were sequenced.The sequences were aligned with other mumps virus sequences downloaded from GenBank using Mega 4.1 software.Results Fourteen isolated strains were closely related to other reference strains of F genotypes.In SH gene,the homology of nucleotide and amino acid among the fourteen isolated strains were 98.3%-100.0%and 96.5%-100.0%,respectively,and 92.6%%-99.4%and 87.7%-100.0% of homology when compared with that of strains isolated from other provinces in China,respectively.Wsh1 and Wsh2 strains had less homology when compared to other strains of F genotypes.The fourteen strains had homology of 84.5%-85.1%and 77.2%compared to vaccine strains on nucleotide and amino acid,respectively,and had homology of 83.4%-90.9% and 70.1%-86.0% compared to that of other genotypes.In HN gene,the homology of nucleotide and amino acid among the six isolated strains were 99.3%-99.5% and 99.1%-99.7%,respectively,and also 99.8% and 99.8% of homology respectively when compared to the SP strain in China.All the six strains had homology of 92.4%-93.2% and 95.5%-96.4% when compared to the vaecine strains on nucleotide and amino acid,respectively,and had homology of 94.7%-96.8% and 95.5%-99.1%compared to other genotypes.Conclusion Fourteen strains isolated in Yunnan from 2007 to 2009belonged to F genotype of MuV while the HN gene seemed more conservative than SH gene.