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Caracas, Venezuela

Camacho E.,Venezuelan Institute for Scientific Research | Leon-Navarro I.,Venezuelan Institute for Scientific Research | Rodriguez-Brito S.,Venezuelan Institute for Scientific Research | Mendoza M.,Institute Biomedicina | Nino-Vega G.A.,Venezuelan Institute for Scientific Research
BMC Infectious Diseases | Year: 2015

Background: Sporotrichosis is a cutaneous and subcutaneous fungal disease of humans and other mammals, known to be caused by the Sporothrix schenckii species complex, which comprises four species of clinical importance: S. brasiliensis, S. globosa, S. luriei, and S. schenckii sensu stricto. Of them, S. globosa and S. schenckii s. str. show global distribution and differences in global frequency as causal agents of the disease. In the Americas, only three species are present: S. schenckii s. str., S. brasiliensis (so far, only reported in Brazil), and S. globosa. In Venezuela, since the first case of sporotrichosis reported in 1935, S. schenckii have been considered its unique etiological agent. In the present work, the presence of more than one species in the country was evaluated. Methods: By phenotypic key features and molecular phylogeny analyses, we re-examined 30 isolates from diverse Venezuelan regions belonging to the fungi collection of Instituto de Biomedicina, Caracas, Venezuela, and national reference center for skin diseases. All isolates were collected between 1973 and 2013, and maintained in distilled water. Results: Sporotrichosis in Venezuela is mainly caused by S. schenckii s. str. (70%). However, a significant proportion (30%) of sporotrichosis cases in the country can be attributable to S. globosa. A correlation between intraspecific genotypes and clinical presentation is proposed. Conclusions: Our data suggest that sporotrichosis various clinical forms might be related to genetic diversity of isolates, and possibly, to diverse virulence profiles previously reported in the S. schenckii species complex. Sporothrix globosa was found to be the causative agent of 30% of sporotrichosis for the Venezuelan cases re-examined, the highest frequency of this species so far reported in the Americas. The high genetic variability presented by S. schenckii s. str. indicates that species distinction based on phenotypic key features could be a challenging and uncertain task; molecular identification should be always employed. © 2015 Camacho et al.; licensee BioMed Central. Source

Cortesia C.,Venezuelan Institute for Scientific Research | Lopez G.J.,Venezuelan Institute for Scientific Research | de Waard J.H.,Institute Biomedicina | Takiff H.E.,Venezuelan Institute for Scientific Research
Journal of Antimicrobial Chemotherapy | Year: 2010

Background: Non-tuberculous mycobacteria (NTM) are increasingly important as opportunistic infections after major and minor surgical procedures, likely because they are ubiquitous and not effectively killed by many commonly used disinfectants. Outbreaks of soft tissue infections with NTM appeared related to the use of commercial disinfectants based on quaternary ammonium compounds (QACs). Methods: We studied the survival of clinical and environmental isolates of Mycobacterium abscessus, Mycobacterium massiliense, Mycobacterium chelonae and Mycobacterium fortuitum after 20 min, 60 min or 24 h exposures to different QACs, and the surviving bacteria were then re-exposed to QACs to see if the percentage of surviving bacteria had increased. The bacteria were labelled with a dnaA-gfp fusion and their level of QAC resistance monitored as increasing fluorescence. The QAC-resistant bacteria were then serially restreaked onto non-selective medium and retested for QAC survival. Results: The frequency of survivors was <1 in 105 bacteria with Mycobacterium smegmatis, but >1 in 100 with the other mycobacteria studied. Different environmental and clinical isolates had similar QAC MICs, but QAC survivors of each strain were resistant. The QAC-surviving strains reverted to the original, non-resistant phenotype after several passages on non-selective medium. Conclusions: QACs should not be used in settings where even minimally invasive procedures are performed, as they select for a non-genetically determined reversible resistant phenotype that appears at high frequency with several rapidly growing mycobacterial species associated with healthcare-related infections. M. smegmatis behaves differently and is not an adequate model for testing the activity of disinfectants against NTM. © The Author 2010. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. Source

In general, it has been reported that rotavirus infection was detected year round in tropical countries. However, studies in Venezuela and Brazil suggest a seasonal behavior of the infection. On the other hand, some studies link infection with climatic variables such as rainfall. This study analyzes the pattern of behavior of the rotavirus infection in Carabobo-Venezuela (2001-2005), associates the seasonality of the infection with rainfall, and according to the seasonal pattern, estimates the age of greatest risk for infection. The analysis of the rotavirus temporal series and accumulated precipitation was performed with the software SPSS. The infection showed two periods: high incidence (November-April) and low incidence (May- October). Accumulated precipitation presents an opposite behavior. The highest frequency of events (73.8% 573/779) for those born in the period with a low incidence of the virus was recorded at an earlier age (mean age 6.5 ± 2.0 months) when compared with those born in the station of high incidence (63.5% 568/870, mean age 11.7 ± 2.2 months). Seasonality of the infection and the inverse relationship between virus incidence and rainfall was demonstrated. In addition, it was found that the period of birth determines the age and risk of infection. This information generated during the pre-vaccine period will be helpful to measure the impact of the vaccine against the rotavirus. © 2015, Instituto de Investigaciones Clinicas. All rights reserved. Source

Torres J.,Instituto Mexicano del Seguro Social | Correa P.,Vanderbilt University | Ferreccio C.,University of Chile | Hernandez-Suarez G.,Instituto Nacional Of Cancerologia | And 4 more authors.
Cancer Causes and Control | Year: 2013

In Latin America, gastric cancer is a leading cancer, and countries in the region have some of the highest mortality rates worldwide, including Chile, Costa Rica, and Colombia. Geographic variation in mortality rates is observed both between neighboring countries and within nations. We discuss epidemiological observations suggesting an association between altitude and gastric cancer risk in Latin America. In the Americas, the burden of gastric cancer mortality is concentrated in the mountainous areas along the Pacific rim, following the geography of the Andes sierra, from Venezuela to Chile, and the Sierra Madre and Cordillera de Centroamérica, from southern Mexico to Costa Rica. Altitude is probably a surrogate for host genetic, bacterial, dietary, and environmental factors that may cluster in the mountainous regions. For example, H. pylori strains from patients of the Andean Nariño region of Colombia display European ancestral haplotypes, whereas strains from the Pacific coast are predominantly of African origin. The observation of higher gastric cancer rates in the mountainous areas is not universal: the association is absent in Chile, where risk is more strongly associated with the age of H. pylori acquisition and socio-economic determinants. The dramatic global and regional variations in gastric cancer incidence and mortality rates offer the opportunity for scientific discovery and focused prevention programs. © 2012 Springer Science+Business Media Dordrecht. Source

Truman R.W.,Louisiana State University | Singh P.,Ecole Polytechnique Federale de Lausanne | Sharma R.,Louisiana State University | Busso P.,Ecole Polytechnique Federale de Lausanne | And 9 more authors.
New England Journal of Medicine | Year: 2011

Background: In the southern region of the United States, such as in Louisiana and Texas, there are autochthonous cases of leprosy among native-born Americans with no history of foreign exposure. In the same region, as well as in Mexico, wild armadillos are infected with Mycobacterium leprae. methods: Whole-genome resequencing of M. leprae from one wild armadillo and three U.S. patients with leprosy revealed that the infective strains were essentially identical. Comparative genomic analysis of these strains and M. leprae strains from Asia and Brazil identified 51 single-nucleotide polymorphisms and an 11-bp insertion-deletion. We genotyped these polymorphic sites, in combination with 10 variable-number tandem repeats, in M. leprae strains obtained from 33 wild armadillos from five southern states, 50 U.S. outpatients seen at a clinic in Louisiana, and 64 Venezuelan patients, as well as in four foreign reference strains. results: The M. leprae genotype of patients with foreign exposure generally reflected their country of origin or travel history. However, a unique M. leprae genotype (3I-2-v1) was found in 28 of the 33 wild armadillos and 25 of the 39 U.S. patients who resided in areas where exposure to armadillo-borne M. leprae was possible. This genotype has not been reported elsewhere in the world. conclusions: Wild armadillos and many patients with leprosy in the southern United States are infected with the same strain of M. leprae. Armadillos are a large natural reservoir for M. leprae, and leprosy may be a zoonosis in the region. Copyright © 2011 Massachusetts Medical Society. All rights reserved. Source

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