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Zenteno-Cuevas R.,University of Veracruz | Silva-Hernandez F.X.,University of Veracruz | Mendoza-Damian F.,Laboratorio Estatal Of Salud Publica Del Estado Of Mexico | Ramirez-Hernandez M.D.,Laboratorio Estatal Of Salud Publica Del Estado Of Mexico | And 7 more authors.
Memorias do Instituto Oswaldo Cruz | Year: 2013

Tuberculosis (TB) is an infectocontagious respiratory disease caused by members of the Mycobacterium tuberculosis complex. A 7 base pair (bp) deletion in the locus polyketide synthase (pks)15/1 is described as polymorphic among members of the M. tuberculosis complex, enabling the identification of Euro-American, Indo-Oceanic and Asian lineages. The aim of this study was to characterise this locus in TB isolates from Mexico. One hundred twenty clinical isolates were recovered from the states of Veracruz and Estado de Mexico. We determined the nucleotide sequence of a ± 400 bp fragment of the locus pks15/1, while genotypic characterisation was performed by spoligotyping. One hundred and fifty isolates contained the 7 bp deletion, while five had the wild type locus. Lineages X (22%), LAM (18%) and T (17%) were the most frequent; only three (2%) of the isolates were identified as Beijing and two (1%) EAI-Manila. The wild type pks15/1 locus was observed in all Asian lineage isolates tested. Our results confirm the utility of locus pks15/1 as a molecular marker for identifying Asian lineages of the M. tuberculosis complex. This marker could be of great value in the epidemiological surveillance of TB, especially in countries like Mexico, where the prevalence of such lineages is unknown. Source


Pfeiler E.,Research Center en Alimentacion y Desarrollo | Flores-Lopez C.A.,University of Maryland University College | Mada-Velez J.G.,Institute Seguridad Y Servicios Sociales Of Los Trabajadores Del Estado Of Sonora Isssteson | Escalante-Verdugo J.,Laboratorio Estatal Of Salud Publica | And 2 more authors.
The Scientific World Journal | Year: 2013

The population genetics and phylogenetic relationships of Culex mosquitoes inhabiting the Sonoran Desert region of North America were studied using mitochondrial DNA and microsatellite molecular markers. Phylogenetic analyses of mitochondrial cytochrome c oxidase subunit I (COI) from mosquitoes collected over a wide geographic area, including the Baja California peninsula, and mainland localities in southern Arizona, USA and Sonora, Mexico, showed several well-supported partitions corresponding to Cx. quinquefasciatus, Cx. tarsalis, and two unidentified species, Culex sp. 1 and sp. 2. Culex quinquefasciatus was found at all localities and was the most abundant species collected. Culex tarsalis was collected only at Tucson, Arizona and Guaymas, Sonora. The two unidentified species of Culex were most abundant at Navojoa in southern Sonora. Haplotype and nucleotide diversities in the COI gene segment were substantially lower in Cx. quinquefasciatus compared with the other three species. Analysis of molecular variance revealed little structure among seven populations of Cx. quinquefasciatus, whereas significant structure was found between the two populations of Cx. tarsalis. Evidence for an historical population expansion beginning in the Pleistocene was found for Cx. tarsalis. Possible explanations for the large differences in genetic diversity between Cx. quinquefasciatus and the other species of Culex are presented. © 2013 Edward Pfeiler et al. Source


Bolado-Martinez E.,University of Sonora | Perez-Mendoza A.,University of Sonora | Alegria-Morquecho F.M.,University of Sonora | Candia-Plata M.C.,University of Sonora | And 2 more authors.
Salud Publica de Mexico | Year: 2012

Objective: To perform the analysis of specific regions of the major genes associated with resistance to isoniazid or rifampin. Materials and methods: Twenty two M. tuberculosis strains, isolated from human samples obtained in Sonora, Mexico. Specific primers for hotspots of the rpoB, katG, inhA genes and the ahpC-oxyR intergenic region were used. The purified PCR products were sequenced. Results: Mutations in the promoter of inhA, the ahpC-oxyR region, and codon 315 of katG and in 451 or 456 codons of rpoB, were identified. Conclusions: Detection of mutations not previously reported requires further genotypic analysis of Mycobacterium tuberculosis isolates in Sonora. © 2006 INSP. Source


Zenteno-Cuevas R.,University of Veracruz | Cuevas-Cordoba B.,University of Veracruz | Cuellar A.,Laboratorio Estatal Of Salud Publica
Canadian Journal of Microbiology | Year: 2012

Mutations at codons 526 and 531 in the rpoB gene and at 315 in the katG gene are considered diagnostic markers for resistance to rifampin and isoniazid in tuberculosis. The aim of this study was to design and evaluate three Taq- Man probes for the identification of these mutations in 138 respiratory samples positive for acid-fast bacilli, and 32 clinical isolates from a region with considerable levels of drug resistance. The specificities of the probes for the diagnosis of resistance to both drugs were 100%; however, the sensitivities were calculated to be 50% for isoniazid and 56% for rifampin. DNA sequencing of rpoB and katG; and the spoligotyping assay of the clinical isolates, confirmed the diversity of the mutations and the presence of 11 spoligotypes with a shared international type and eight unique spoligotypes. Analysis of the respiratory samples identified 22 (16%) as drug-resistant and 4 (3%) as multidrug-resistant tuberculosis. The diagnostic value of the TaqMan probes was compromised by the diversity of mutations found in the clinical isolates. This highlights the need for better understanding of the molecular mechanisms responsible for drug resistance prior to the use of molecular probes, especially in regions with significant levels of drug-resistant tuberculosis. Source


Vazquez-Garciduenas M.,Universidad Michoacana de San Nicolas de Hidalgo | Romero-Perez N.L.,Universidad Michoacana de San Nicolas de Hidalgo | Figueroa-Aguilar G.A.,Laboratorio Estatal Of Salud Publica | Jaime-Sanchez J.L.,Laboratorio Estatal Of Salud Publica | Vazquez-Marrufo G.,Universidad Michoacana de San Nicolas de Hidalgo
Journal of Infection in Developing Countries | Year: 2014

Introduction: Gastroenteritis outbreaks in prisons represent a public health risk worldwide. Identifying and characterizing the etiological agents of gastroenteritis outbreaks in prisons is important for implementing effective prevention and infection control measures. We present the first studied case of a gastroenteritis outbreak in a Mexican prison. Methodology: Rectal swab samples were obtained from affected inmates. Standard microbiological techniques were used for isolating Salmonella enterica. Isolates were typed by PCR assays of DNA repetitive elements (ERIC, BOX, REP) and RAPD. Antibiotic resistance profiles were performed by the Kirby-Bauer method. Results: S. enterica serotype Oranienburg was responsible for the outbreak affecting 150 inmates. All patients presented diarrhea, and 70% of them also presented vomiting, with no fatal cases. The origin of the outbreak was undetermined due to the difficulty of gathering epidemiological information, but was likely the result of consumption of shrimp broth or a cantaloupe melon beverage. REP, BOX, and ERIC analyses of 26 serotype Oranienburg strains resulted in Simpson discrimination index (D) values of 0, 0.5507, and 0.5661, respectively. The D values from DG93-RAPD analyses and from the combined ERIC-BOX-DG93 markers were 0.7753 and 0.6092, respectively. All strains showed multiresistance to antibiotics. Conclusions: This is the only studied case of a gastroenteritis outbreak in a Mexican prison, and of the first such outbreak caused by serotype Oranienburg. The combined ERIC, BOX, and RAPD markers adequately assessed the genotype diversity of analyzed strains. Penitentiary personnel or inmates involved in outbreaks might spread multiresistant strains outside of the facility. © 2014 Vázquez-Garcidueñas et al. Source

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