Publications by authors named "Alejandro Escobar-Gutiérrez"

38 Publications

Interleukin 4 deficiency limits the development of a lupus-like disease in mice triggered by phospholipids in a non-bilayer arrangement.

Scand J Immunol 2021 Mar 25;93(3):e13002. Epub 2020 Dec 25.

Laboratorio de Biomembranas, Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México.

Non-bilayer phospholipids arrangements (NPAs) are transient molecular associations different from lipid bilayers. When they become stable, they can trigger a disease in mice resembling human lupus, which is mainly characterized by the production of anti-NPA IgG antibodies. NPAs are stabilized on liposomes or cell bilayers by the drugs procainamide or chlorpromazine, which produce drug-induced lupus in humans. Here, we evaluated the participation of the T 2 response, through its hallmark cytokine IL-4, on the development of the lupus-like disease in mice. Wild-type or IL-4 knockout BALB/c mice received liposomes bearing drug-induced NPAs, the drugs alone, or an anti-NPA monoclonal antibody (H308) to induce the lupus-like disease (the last two procedures stabilize NPAs on mice cells). IL-4 KO mice showed minor disease manifestations, compared to wild-type mice, with decreased production of anti-NPA IgG antibodies, no anti-cardiolipin, anti-histones and anticoagulant antibodies, and no kidney or skin lesions. In these mice, H308 was the only inducer of anti-NPA IgG antibodies. These findings indicate that IL-4 has a central role in the development of the murine lupus-like disease induced by NPA stabilization.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/sji.13002DOI Listing
March 2021

The First exploratory spatial distribution analysis of tuberculosis and associated factors in Tonala, Mexico.

J Infect Dev Ctries 2020 02 29;14(2):207-213. Epub 2020 Feb 29.

Medical and Pharmaceutical Biotechnology, Center for Research and Applied Technology in Jalisco (CIATEJ) Guadalajara, Mexico.

Introduction: The US-Mexico region is at high risk of elevated tuberculosis (TB) incidence due to mobility and migration. Knowledge of how socio-demographic factors varies geographically, provides clues to understanding the determinants of tuberculosis and may provide guidance for regional prevention and control strategies to improve public health in Mexico. The aim of the present study was to describe the epidemiologic characteristics and spatial patterns of the incidence of tuberculosis in Tonala, Jalisco (Mexico) from 2013-2015.

Methodology: The Surveillance System Database from the Health Department, complemented by information from the National Institute of Statistics and Geography, was used to obtain data for a spatial-temporal analysis of TB cases. For the geographical analysis map creation and geoinformation storing, ArcGIS software was used.

Results: This study sought to characterize problem areas and jurisdictional locations of TB via a spatial approach based on analyses of case distributions and individual patient variables. The study found that tuberculosis cases were dispersed throughout Tonala County and were mainly concentrated on the Guadalajara city border. The TB cases were mainly individuals between 31 and 45 years old. Most of the cases reported during the observation period were male patients, and most cases primarily had lung involvement; however, there were quite a few cases with lymph node and intestinal disease.

Conclusion: Our findings show that TB cases are essentially located in areas close to the city of Guadalajara and that most TB cases were pulmonary cases spread throughout the whole jurisdiction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3855/jidc.11873DOI Listing
February 2020

A unique immune signature of serum cytokine and chemokine dynamics in patients with Zika virus infection from a tropical region in Southern Mexico.

Int J Infect Dis 2020 May 17;94:4-11. Epub 2020 Feb 17.

Departamento de Infectología, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.

Objectives: To describe the kinetics of circulating cytokines and chemokines in humans with ZIKAV infection.

Methods: Serum levels of different immune mediators in patients with ZIKAV infection were measured at distinct stages of the disease, as well as in culture supernatants from human monocytes infected with a clinical ZIKAV isolate. We also looked for clinical features associated with specific immune signatures among symptomatic patients.

Results: We evaluated 23 ZIKAV-infected patients. Their mean age was 32 ± 8.3 years and 65% were female. ZIKAV patients showed elevated IL-9, IL-17A, and CXCL10 levels at acute stages of the disease. At day 28, levels of CCL4 and CCL5 were increased, whereas IL-1RA, CXCL8 and CCL2 were decreased. At baseline, IL-7 was increased among patients with headache, whereas CCL2, and CCL3 were decreased in patients with bleeding and rash, respectively. Our clinical ZIKAV isolate induced a broad immune response in monocytes that did not resemble the signature observed in ZIKAV patients.

Conclusions: We showed a unique immune signature in our cohort of ZIKAV-infected patients. Our study may provide valuable evidence helpful to identify immune correlates of protection against ZIKAV.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijid.2020.02.014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7362833PMC
May 2020

Genetic polymorphisms present in IL10, IL23R, NOD2, and ATG16L1 associated with susceptibility to inflammatory bowel disease in Mexican population.

Eur J Gastroenterol Hepatol 2020 01;32(1):10-16

Unidad de Investigación Multidisciplinaria, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México.

Objective: Ulcerative colitis and Crohn's disease are the two clinical forms of inflammatory bowel disease (IBD). Diverse studies have shown the association of single nucleotide polymorphism (SNP) in molecules of the immune system and the occurrence of IBD. Here, several SNPs of the immune system with controversial results for their association with UC and CD were evaluated in a Mexican population.

Methods: SNPs rs1800896, rs3024505 (IL-10); rs11209026 (IL23R); rs2066844, rs2066845 (NOD-2), and rs2241880 (ATG16L1) were assessed in 93 patients with IBD and 200 healthy controls by hybridization probes and quantitative PCR.

Results: The AG genotype for rs1800896 was associated with an increased risk for both UC and CD (P = 0.005 and P = 0.026, respectively); whereas the AA genotype presents a negative association (P = 0.011 for UC, and 0.0038 for CD). For this SNP, G allele was associated with risk of UC (P = 0-043) but not for CD. For the rs3024505 in IL-10, T allele was associated with UC (P = 0.011). Moreover, this allele was associated with early onset of UC (P = 0.033) and with the use of steroid treatment (P = 0.019). No significant differences for NOD2 (rs2066844T and rs2066845C), IL23R (rs11209026), and ATG16L1 (rs22411880) were found between cases and controls and the homozygous TT genotype for rs2066844 and CC for rs2066845 were not observed.

Conclusion: Our results show both genotypic and phenotypic associations of IL-10 SNPs with IBD but not with the other immune-related SNPs studied in this Mexican cohort.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/MEG.0000000000001540DOI Listing
January 2020

Association of Single-Nucleotide Polymorphisms in Immune-Related Genes with Development of Dengue Hemorrhagic Fever in a Mexican Population.

Viral Immunol 2018 04 13;31(3):249-255. Epub 2017 Nov 13.

2 Laboratorio de Inmunobiología de Enfermedades Infecciosas, Unidad de Investigación Multidisciplinaria, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México , Cuautitlán Izcalli, México .

Single-nucleotide polymorphisms (SNPs) occurring in immune-related genes have been associated with risk or protection for development of dengue, depending on ethnicity. Here, we genotyped seven SNPs located in immune response-related genes to identify their association with severe forms of dengue in patients from an endemic region in Mexico. One hundred and thirty-eight patients with dengue fever (DF), thirty-one dengue hemorrhagic fever (DHF) patients, as well as 304 healthy donors were genotyped by using a TaqMan-based approach. SNP analysis, including rs1800629 (TNF), rs4804803 (CD209), rs2780831 (JAK1), rs1801274 (FCGR2A), rs231775 (CTLA4), rs12979860, and rs8099917 (IFNL3), was performed. The rs1800629 A-allele in the TNF gene was associated with an increased risk of DHF (OR = 3.4, CI = 1.235-9.284 p = 0.0212) whereas SNPs rs4804803, rs2780831, rs1801274, rs231775, rs12979860, and rs8099917 showed no association in this cohort. These results show that allelic variations in TNF can play an important role in the development of DHF. However, the lack of association between all remaining SNPs and DHF suggests that the genetic background might directly modify the role of these immune-related molecules, leading to the milder illness often observed in a Mexican population.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/vim.2017.0069DOI Listing
April 2018

Comparison of DOT-ELISA and Standard-ELISA for Detection of the Vibrio cholerae Toxin in Culture Supernatants of Bacteria Isolated from Human and Environmental Samples.

Indian J Microbiol 2016 Sep 27;56(3):379-82. Epub 2016 May 27.

Laboratorio de Producción de Sueros, Instituto de Diagnóstico y Referencia Epidemiológicos, Secretaria de Salud, Ciudad de México, Mexico.

A comparison of DOT-ELISA and Standard-ELISA was made for detection of Vibrio cholerae toxin in culture supernatants of bacteria isolated from human and environmental samples. A total of 293 supernatants were tested in a double blind assay. A correlation of 100 % was obtained between both techniques. The cholera toxin was found in 20 Inaba and 3 Ogawa strains. Positive samples were from seafood (17 samples), potable water (1 sample) and sewage (5 samples). The DOT-ELISA was useful as the standard-ELISA to confirm the presence of cholera toxin in the environmental samples.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12088-016-0596-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4920772PMC
September 2016

The Cellular Bases of Antibody Responses during Dengue Virus Infection.

Front Immunol 2016 6;7:218. Epub 2016 Jun 6.

Department of Cell Biology, Center for Advanced Research, The National Polytechnic Institute, Cinvestav-IPN , Mexico City , Mexico.

Dengue virus (DENV) is one of the most significant human viral pathogens transmitted by mosquitoes and can cause from an asymptomatic disease to mild undifferentiated fever, classical dengue, and severe dengue. Neutralizing memory antibody (Ab) responses are one of the most important mechanisms that counteract reinfections and are therefore the main aim of vaccination. However, it has also been proposed that in dengue, some of these class-switched (IgG) memory Abs might worsen the disease. Although these memory Abs derive from B cells by T-cell-dependent processes, we know rather little about the (acute, chronic, or memory) B cell responses and the complex cellular mechanisms generating these Abs during DENV infections. This review aims to provide an updated and comprehensive perspective of the B cell responses during DENV infection, starting since the very early events such as the cutaneous DENV entrance and the arrival into draining lymph nodes, to the putative B cell activation, proliferation, and germinal centers (GCs) formation (the source of affinity-matured class-switched memory Abs), till the outcome of GC reactions such as the generation of plasmablasts, Ab-secreting plasma cells, and memory B cells. We discuss topics very poorly explored such as the possibility of B cell infection by DENV or even activation-induced B cell death. The current information about the nature of the Ab responses to DENV is also illustrated.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2016.00218DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4893500PMC
July 2016

Multiregion deep sequencing of hepatitis C virus: An improved approach for genetic relatedness studies.

Infect Genet Evol 2016 Mar 28;38:138-145. Epub 2015 Dec 28.

Department of Biology, Institute of Bioscience, Language and Exact Science, São Paulo State University, São José do Rio Preto, Sao Paulo, Brazil.

Hepatitis C virus (HCV) is a major public health problem that affects more than 180 million people worldwide. Identification of HCV transmission networks is of critical importance for disease control. HCV related cases are often difficult to identify due to the characteristic long incubation period and lack of symptoms during the acute phase of the disease, making it challenging to link related cases to a common source of infection. Additionally, HCV transmission chains are difficult to trace back since viral variants from epidemiologically linked cases are genetically related but rarely identical. Genetic relatedness studies primarily rely on information obtained from the rapidly evolving HCV hypervariable region 1 (HVR1). However, in some instances, the rapid divergence of this region can lead to loss of genetic links between related isolates, which represents an important challenge for outbreak investigations and genetic relatedness studies. Sequencing of multiple and longer sub-genomic regions has been proposed as an alternative to overcome the limitations imposed by the rapid molecular evolution of the HCV HVR1. Additionally, conventional molecular approaches required to characterize the HCV intra-host genetic variation are laborious, time-consuming, and expensive while providing limited information about the composition of the viral population. Next generation sequencing (NGS) approaches enormously facilitate the characterization of the HCV intra-host population by detecting rare variants at much lower frequencies. Thus, NGS approaches using multiple sub-genomic regions should improve the characterization of the HCV intra-host population. Here, we explore the usefulness of multiregion sequencing using a NGS platform for genetic relatedness studies among HCV cases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.meegid.2015.12.020DOI Listing
March 2016

Influence of levamisole and Freund's adjuvant on mouse immunisation with antigens of adults of the liver fluke Fasciola hepatica Linnaeus, 1758.

Folia Parasitol (Praha) 2015 Aug 28;62. Epub 2015 Aug 28.

Instituto de Diagnostico y Referencia Epidemiologicos, Secretaria de Salud, Mexico D. F., Mexico;

We have studied the influence of both levamisole (AL) and Freund's adjuvant (AF) on the immunisation of mice with the secretory antigens of adults of the liver fluke Fasciola hepatica Linnaeus, 1758. Total IgG antibodies were detected in all groups where the F. hepatica antigen was administered, been levels of IgG1 increased respect to IgG2a antibodies. During immunisation, IL-4 and IFN-γ were only detected in AL and AF groups, but after infection, IL-4 boosted in all groups. IFN-γ increased two fold in AF and AL groups compared to the saline solution (AS) group. Worm recovering was of 32-35% in groups administered without antigen whereas in AS, AL and AF groups recovering was of 25%, 12% and 8%, respectively. Macroscopical lesions in the liver were scarce in AL and AF groups. Our data suggest that immunisation of mice with antigens of F. hepatica enhances the immune response avoiding both liver damage and worm establishment after challenge infection. The murine model of fasciolosis has appeared to be useful to elucidate the mechanism by which the parasite modulates immune responses toward a Th2 type but also the development of Th1 type-inducing vaccines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.14411/fp.2015.047DOI Listing
August 2015

Human multidrug-resistant Mycobacterium bovis infection in Mexico.

Tuberculosis (Edinb) 2015 Dec 13;95(6):802-809. Epub 2015 Aug 13.

Instituto de Diagnóstico y Referencia Epidemiológicos, Secretaría de Salud, Mexico City, Mexico.

Here, we describe the molecular characterization of six human Mycobacterium bovis clinical isolates, including three multidrug resistant (MDR) strains, collected in Mexico through the National Survey on Tuberculosis Drug Resistance (ENTB-2008), a nationally representative survey conducted during 2008-2009 in nine states with a stratified cluster sampling design. The genetic background of bovine M. bovis strains identified in three different states of Mexico was studied in parallel to assess molecular relatedness of bovine and human strains. Additionally, resistance to first and second line anti-tuberculosis (TB) drugs and molecular identification of mutations conferring drug resistance was also performed. All strains were characterized by spoligotyping and 24-loci MIRU-VNTRs, and analyzed using the SITVIT2 (n = 112,000 strains) and SITVITBovis (n = 25,000 strains) proprietary databases of Institut Pasteur de la Guadeloupe. Furthermore, data from this study (n = 55 isolates), were also compared with genotypes recorded for M. bovis from USA (n = 203), Argentina (n = 726), as well as other isolates from Mexico (independent from the present study; n = 147), to determine any evidence for genetic relatedness between circulating M. bovis strains. The results showed that all human M. bovis cases were not genetically related between them or to any bovine strain. Interestingly, a high degree of genetic variability was observed among bovine strains. Several autochthonous and presumably imported strains were identified. The emergence of drug-resistant M. bovis is an important public health problem that jeopardizes the success of TB control programs in the region.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tube.2015.07.010DOI Listing
December 2015

Advanced molecular surveillance of hepatitis C virus.

Viruses 2015 Mar 13;7(3):1153-88. Epub 2015 Mar 13.

Department of Biology, Institute of Bioscience, Language and Exact Science, Sao Paulo State University, Sao Jose do Rio Preto, SP 15054-000, Brazil.

Hepatitis C virus (HCV) infection is an important public health problem worldwide. HCV exploits complex molecular mechanisms, which result in a high degree of intrahost genetic heterogeneity. This high degree of variability represents a challenge for the accurate establishment of genetic relatedness between cases and complicates the identification of sources of infection. Tracking HCV infections is crucial for the elucidation of routes of transmission in a variety of settings. Therefore, implementation of HCV advanced molecular surveillance (AMS) is essential for disease control. Accounting for virulence is also important for HCV AMS and both viral and host factors contribute to the disease outcome. Therefore, HCV AMS requires the incorporation of host factors as an integral component of the algorithms used to monitor disease occurrence. Importantly, implementation of comprehensive global databases and data mining are also needed for the proper study of the mechanisms responsible for HCV transmission. Here, we review molecular aspects associated with HCV transmission, as well as the most recent technological advances used for virus and host characterization. Additionally, the cornerstone discoveries that have defined the pathway for viral characterization are presented and the importance of implementing advanced HCV molecular surveillance is highlighted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/v7031153DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4379565PMC
March 2015

Hepatitis C virus molecular evolution: transmission, disease progression and antiviral therapy.

World J Gastroenterol 2014 Nov;20(43):15992-6013

Maria Victoria Preciado, Pamela Valva, Laboratorio de Biología Molecular, División Patología, Hospital de Niños "Ricardo Gutiérrez", Buenos Aires C1425EFD, Argentina.

Hepatitis C virus (HCV) infection represents an important public health problem worldwide. Reduction of HCV morbidity and mortality is a current challenge owned to several viral and host factors. Virus molecular evolution plays an important role in HCV transmission, disease progression and therapy outcome. The high degree of genetic heterogeneity characteristic of HCV is a key element for the rapid adaptation of the intrahost viral population to different selection pressures (e.g., host immune responses and antiviral therapy). HCV molecular evolution is shaped by different mechanisms including a high mutation rate, genetic bottlenecks, genetic drift, recombination, temporal variations and compartmentalization. These evolutionary processes constantly rearrange the composition of the HCV intrahost population in a staging manner. Remarkable advances in the understanding of the molecular mechanism controlling HCV replication have facilitated the development of a plethora of direct-acting antiviral agents against HCV. As a result, superior sustained viral responses have been attained. The rapidly evolving field of anti-HCV therapy is expected to broad its landscape even further with newer, more potent antivirals, bringing us one step closer to the interferon-free era.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3748/wjg.v20.i43.15992DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4239486PMC
November 2014

Vertical transmission of hepatitis C virus: a tale of multiple outcomes.

Infect Genet Evol 2013 Dec 18;20:465-70. Epub 2013 Oct 18.

Instituto de Diagnóstico y Referencia Epidemiológicos, Mexico City, Mexico.

Globally, hepatitis C virus (HCV) infection affects approximately 130 million people and 3 million new infections occur annually. HCV is also recognized as an important cause of chronic liver disease in children. The absence of proofreading properties of the HCV RNA polymerase leads to a highly error prone replication process, allowing HCV to escape host immune response. The adaptive nature of HCV evolution dictates the outcome of the disease in many ways. Here, we investigated the molecular evolution of HCV in three unrelated children who acquired chronic HCV infection as a result of mother-to-child transmission, two of whom were also coinfected with HIV-1. The persistence of discrete HCV variants and their population structure were assessed using median joining network and Bayesian approaches. While patterns of viral evolution clearly differed between subjects, immune system dysfunction related to HIV coinfection or persistent HCV seronegativity stand as potential mechanisms to explain the lack of molecular evolution observed in these three cases. In contrast, treatment of HCV infection with PegIFN, which did not lead to sustained virologic responses in all 3 cases, was not associated with commensurate variations in the complexity of the variant spectrum. Finally, the differences in the degree of divergence suggest that the mode of transmission of the virus was not the main factor driving viral evolution.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.meegid.2013.10.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5042690PMC
December 2013

Participation of CD161(+) and invariant natural killer T cells in pediatric asthma exacerbations.

Allergy Asthma Proc 2013 Jan-Feb;34(1):84-92

Departamento de Investigaciones Inmunológicas, Instituto de Diagnóstico y Referencia Epidemiológicos, Mexico City, Mexico.

Asthma has been defined as a disease of chronic airway inflammation in which many cells and cellular products participate with variable degrees of airflow obstruction and hyperresponsiveness that lead to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing. Prominent among these cellular elements are two cell types referred to as the invariant natural killer T (iNKT) cells and a subpopulation of T cells expressing the molecule CD161, which are both thought to play a role in the pathogenesis of asthma. Although the presence of iNKT and other CD161(+) cells in murine models has been associated with asthma, relatively few studies have been performed in the adult patient with asthma that have been often conflicting and even fewer studies are available in children. The present study was performed to investigate the peripheral blood frequencies of iNKT and CD161(+) T cells in children with asthma. A total of 35 children, 19 stable asthmatic patients, 6 who had experienced an asthmatic attack within 24 hours and had not received any treatment, and 10 healthy controls, aged 6-12 years, were enrolled in the study. iNKT and CD161(+) T-cell frequencies in blood were measured together with quantitative levels of IL-4 and interferon (IFN) γ using a cytofluorimetric approach. The results show that iNKT cells are increased in pediatric asthmatic patients undergoing exacerbations of asthma. These cells also produced less IFN-γ and more IL-4 than children with stable asthma and in healthy control children. These results suggest that iNKT cells might participate in the development of the asthmatic exacerbations. The increased production of IL-4 in conjunction with the decrease of IFN-γ may be mechanistically responsible, at least partially, for the heightening of the immunologic response leading to the asthmatic attack in children. Knowledge of these interactive mechanisms involving the iNKT cell and our understanding of its role in the exacerbation of asthma hold great promise in the development of better diagnostic predictive markers of disease progression as well as new forms of therapeutic interventions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2500/aap.2013.34.3619DOI Listing
August 2013

Genetic diversity among multidrug-resistant Mycobacterium tuberculosis strains in Mexico.

Infect Genet Evol 2013 Mar 16;14:434-43. Epub 2013 Jan 16.

Instituto de Diagnóstico y Referencia Epidemiológicos, Secretaría de Salud, Mexico City, Mexico.

Tuberculosis is an important public health problem in Mexico. However, limited information about the genetic diversity of Mycobacterium tuberculosis strains circulating in the country is available. In this work, 109 multidrug-resistant (MDR) M. tuberculosis isolates collected in 23 different states of Mexico in 2003 were retrospectively characterized by spoligotyping and MIRU-VNTRs. All isolates, except for a single cluster containing two strains (subcluster E1), were split when information from the 12-loci MIRUs and spoligo-pattern was simultaneously analyzed. The discriminative power of 12-loci MIRU-VNTR and spoligotyping, by the Hunter-Gaston index, were 0.9998 and 0.9011, respectively. These findings suggest that almost all cases were epidemiologically unrelated. Instead, the genetic variations observed among these strains are suggestive of emergence of acquired drug-resistance during the course of treatment. The results suggest a high degree of genetic variability and a high frequency of SIT53 (T1 family) spoligotype among the MDR M. tuberculosis isolates included in the study.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.meegid.2012.12.024DOI Listing
March 2013

Rapid hepatitis C virus divergence among chronically infected individuals.

J Clin Microbiol 2013 Feb 5;51(2):629-32. Epub 2012 Dec 5.

Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.

Here, we analyze the viral divergence among hepatitis C virus (HCV) chronic cases infected with genotype 1. The intrahost viral evolution was assessed by deep sequencing using the 454 Genome Sequencer platform. The results showed a rapid nucleotide sequence divergence. This notorious short-term viral evolution is of the utmost importance for the study of HCV transmission, because direct links between related samples were virtually lost. Thus, rapid divergence of HCV significantly affects genetic relatedness studies and outbreak investigations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/JCM.03042-12DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3553878PMC
February 2013

Skin biopsy: a pillar in the identification of cutaneous Mycobacterium tuberculosis infection.

J Infect Dev Ctries 2012 Aug 21;6(8):626-31. Epub 2012 Aug 21.

Facultad de Medicina, UNAM, Hospital General de México, Mexico.

Introduction: The present study aimed to establish the frequency and clinical characteristics of cutaneous tuberculosis among Mexican adult patients.

Methodology: Ninety-five patients with clinically compatible lesions to cutaneous tuberculosis participated in the study. All patients were HIV negative and none of them had previous anti-TB treatment. A skin biopsy was taken from every patient suspected of having tuberculosis, and a histopathologic examination was performed as follows: Ziehl-Neelsen staining; culturing of mycobacteria by Löwenstein-Jensen (L-J) medium; Mycobacteria Growth Indicator Tube detection via BACTEC (MGIT-360); and polymerase chain reaction (PCR) with the sequence of insertion IS6110 for Mycobacterium tuberculosis complex.

Results: Tuberculosis was confirmed in 65 out of 95 cases (68.4%). Identified lesions were scrofuloderma (42 cases, 64.6%); lupus vulgaris (12 cases, 18.4%); warty tuberculosis (six cases, 9.2%); and papulonecrotic tuberculoid (five cases; 7.7%). The Ziehl-Neelsen staining was positive for acid fast bacilli in nine cases (13.8%) and 48 patients were positive for the PCR amplification (73.8%). All skin biopsies resulted positive for tuberculosis. A positive clinical response to the specific treatment was considered a confirmation for tuberculosis. The noninfectious etiology corresponded to 30 cases (31.6%).

Conclusions: Tuberculosis in developing countries is still an important cause of skin lesions which must be studied via histopathological examination and culture due to their low bacillary load. A PCR test is necessary to obtain faster confirmation of the disease and to establish an early, specific and effective treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3855/jidc.2729DOI Listing
August 2012

Comparative effects of levamisole, Staphylococcus, and Freund's adjuvant on rat immunization with excretory and secretory antigens of Trichinella spiralis muscle larvae.

Parasitol Res 2012 Oct 30;111(4):1599-605. Epub 2012 Jun 30.

Instituto de Diagnóstico y Referencia Epidemiológicos, Secretaria de Salud, México D.F., Mexico 11340.

A comparison was made of the effects of levamisole, the bacterial fractions of Staphylococcus, and Freund's adjuvant on the immunization of rats with the excretory and secretory antigens of Trichinella spiralis muscle larvae. Wistar rats were immunized with the antigen and a saline solution, levamisole (LV), Staphylococcus (ST), or Freund's adjuvant (FA). After immunization, rats were infected, and the parasite burden at muscular phase was calculated for each group. Levels of IgG1 and IgG2 antibodies, as well as levels of two cytokines, IL-4 and IFN-γ, were evaluated during the immunization and postinfection periods. Differences were found in the kinetics of antibody production between groups (p < 0.01). In all cases, there was reactivity with the main 45-, 50-, and 55-kDa antigens of Trichinella muscle larvae. Immunization with FA and ST enhanced the production of IgG1, but only FA showed a significant increase in the production of IFN-γ (p < 0.01), resulting in 86% protection against the infection. In contrast, only 60-70% protection was attained in the ST and LV groups (p < 0.01). These data support the idea that levamisole and Staphylococcus can be used as adjuvant to enhance the humoral response and, at the same time, demonstrate that IFN-γ could be involved in protection against Trichinella.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00436-012-2998-3DOI Listing
October 2012

Epidemiology of varicella in Mexico.

J Clin Virol 2012 Sep 30;55(1):51-7. Epub 2012 Jun 30.

Universidad Nacional Autónoma de México, México City, Mexico.

Background: The epidemiological patterns of varicella-zoster virus (VZV) infection, which are strongly associated with climate, are characterized by more frequent infections occurring among children in temperate regions than in the tropics. In temperate regions, varicella exhibits a seasonal cyclic behavior in which the number of cases increases significantly during the winter and spring seasons, further supporting the role of environmental factors in disease transmission. However, the underlying mechanisms responsible for this distinctive behavior are not fully understood. In Mexico, information regarding the epidemiology of varicella is scarce, and the distribution of VZV infection has not been analyzed.

Objectives: In this article we investigate the epidemiological patterns of varicella in Mexico and their relationship with different environmental and demographic factors.

Study Design: A retrospective study was conducted using the data reported by the National Center of Epidemiological Surveillance and Disease Control. The overall varicella incidence was calculated and associated with temperature, overcrowding, age, gender and population density.

Results: The epidemiology of varicella showed an intriguing pattern, in which warmer regions were characterized by higher incidences than in temperate regions. Young children were the most affected age group. There was no correlation between varicella incidence and overcrowding or population density.

Conclusions: The epidemiology of varicella in Mexico significantly departs from the characteristic patterns observed in other tropical latitudes, with some features resembling those commonly associated with temperate regions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcv.2012.06.004DOI Listing
September 2012

Identification of hepatitis C virus transmission using a next-generation sequencing approach.

J Clin Microbiol 2012 Apr 1;50(4):1461-3. Epub 2012 Feb 1.

Instituto de Diagnóstico y Referencia Epidemiológicos, Secretaría de Salud, Mexico City, Mexico.

Here, we describe a transmission event of hepatitis C virus (HCV) among injection drug users. Next-generation sequencing (NGS) was used to assess the intrahost viral genetic variation. Deep amplicon sequencing of HCV hypervariable region 1 allowed for a detailed analysis of the structure of the viral population. Establishment of the genetic relatedness between cases was accomplished by phylogenetic analysis. NGS is a powerful tool with applications in molecular epidemiology studies and outbreak investigations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/JCM.00005-12DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3318530PMC
April 2012

Specific detection of naturally occurring hepatitis C virus mutants with resistance to telaprevir and boceprevir (protease inhibitors) among treatment-naïve infected individuals.

J Clin Microbiol 2012 Feb 23;50(2):281-7. Epub 2011 Nov 23.

Universidad Nacional Autónoma de México, Mexico City, Mexico.

The use of telaprevir and boceprevir, both protease inhibitors (PI), as part of the specifically targeted antiviral therapy for hepatitis C (STAT-C) has significantly improved sustained virologic response (SVR) rates. However, different clinical studies have also identified several mutations associated with viral resistance to both PIs. In the absence of selective pressure, drug-resistant hepatitis C virus (HCV) mutants are generally present at low frequency, making mutation detection challenging. Here, we describe a mismatch amplification mutation assay (MAMA) PCR method for the specific detection of naturally occurring drug-resistant HCV mutants. MAMA PCR successfully identified the corresponding HCV variants, while conventional methods such as direct sequencing, endpoint limiting dilution (EPLD), and bacterial cloning were not sensitive enough to detect circulating drug-resistant mutants in clinical specimens. Ultradeep pyrosequencing was used to confirm the presence of the corresponding HCV mutants. In treatment-naïve patients, the frequency of all resistant variants was below 1%. Deep amplicon sequencing allowed a detailed analysis of the structure of the viral population among these patients, showing that the evolution of the NS3 is limited to a rather small sequence space. Monitoring of HCV drug resistance before and during treatment is likely to provide important information for management of patients undergoing anti-HCV therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/JCM.05842-11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3264164PMC
February 2012

Is ultra-violet radiation the main force shaping molecular evolution of varicella-zoster virus?

Virol J 2011 Jul 27;8:370. Epub 2011 Jul 27.

Departamento de Investigaciones Inmunológicas, Instituto de Diagnóstico y Referencia Epidemiológicos, Secretaría de Salud, México City, México.

Background: Varicella (chickenpox) exhibits a characteristic epidemiological pattern which is associated with climate. In general, primary infections in tropical regions are comparatively less frequent among children than in temperate regions. This peculiarity regarding varicella-zoster virus (VZV) infection among certain age groups in tropical regions results in increased susceptibility during adulthood in these regions. Moreover, this disease shows a cyclic behavior in which the number of cases increases significantly during winter and spring. This observation further supports the participation of environmental factors in global epidemiology of chickenpox. However, the underlying mechanisms responsible for this distinctive disease behavior are not understood completely. In a recent publication, Philip S. Rice has put forward an interesting hypothesis suggesting that ultra-violet (UV) radiation is the major environmental factor driving the molecular evolution of VZV.

Discussion: While we welcomed the attempt to explain the mechanisms controlling VZV transmission and distribution, we argue that Rice's hypothesis takes lightly the circulation of the so called "temperate VZV genotypes" in tropical regions and, to certain degree, overlooks the predominance of such lineages in certain non-temperate areas. Here, we further discuss and present new information about the overwhelming dominance of temperate VZV genotypes in Mexico regardless of geographical location and climate.

Summary: UV radiation does not satisfactorily explain the distribution of VZV genotypes in different tropical and temperate regions of Mexico. Additionally, the cyclic behavior of varicella does not shown significant differences between regions with different climates in the country. More studies should be conducted to identify the factors directly involved in viral spreading. A better understanding of the modes of transmissions exploited by VZV and their effect on viral fitness is likely to facilitate the implementation of preventive measures for disease control.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/1743-422X-8-370DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3162543PMC
July 2011

Molecular epidemiology of autochthonous dengue virus strains circulating in Mexico.

J Clin Microbiol 2011 Sep 20;49(9):3370-4. Epub 2011 Jul 20.

Departamento de Virología, Instituto de Diagnóstico y Referencia Epidemiológicos, Secretaría de Salud, Mexico City, Mexico.

Dengue virus (DENV) is the most important arthropod-borne viral infection in humans. Here, the genetic relatedness among autochthonous DENV Mexican isolates was assessed. Phylogenetic and median-joining network analyses showed that viral strains recovered from different geographic locations are genetically related and relatively homogeneous, exhibiting limited nucleotide diversity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/JCM.00950-11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3165623PMC
September 2011

Interleukin-28B genotyping by melt-mismatch amplification mutation assay PCR analysis using single nucleotide polymorphisms rs12979860 and rs8099917, a useful tool for prediction of therapy response in hepatitis C patients.

J Clin Microbiol 2011 Jul 25;49(7):2706-10. Epub 2011 May 25.

Unidad de Investigación Multidisciplinaria, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Mexico City, Mexico.

Several studies have identified associations between single nucleotide polymorphisms (SNPs) occurring near the interleukin-28B (IL-28B) gene and response to antiviral treatment among hepatitis C virus (HCV) patients. Here, we describe a reliable melt-mismatch amplification mutation assay (melt-MAMA) PCR-based genotyping method for IL-28B which can be used in the management of HCV patients, helping to better define the course of therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/JCM.00877-11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3147879PMC
July 2011

Simultaneous cocirculation of both European varicella-zoster virus genotypes (E1 and E2) in Mexico city.

J Clin Microbiol 2010 May 10;48(5):1712-5. Epub 2010 Mar 10.

Departamento de Genoma de Patógenos, Instituto de Diagnóstico y Referencia Epidemiológicos, Secretaría de Salud, Carpio 470, Mexico City 11340, Mexico.

Full-length genome analysis of varicella-zoster virus (VZV) has shown that viral strains can be classified into seven different genotypes: European (E), Mosaic (M), and Japanese (J), and the E and M genotypes can be further subclassified into E1, E2, and M1 through 4, respectively. The distribution of the main VZV genotypes in Mexico was described earlier, demonstrating the predominance of E genotype, although other genotypes (M1 and M4) were also identified. However, no information regarding the circulation of either E genotype in the country is available. In the present study, we confirm the presence of both E1 and E2 genotypes in the country and explore the possibility of coinfection as the triggering factor for increased virulence among severe cases. A total of 61 different European VZV isolates collected in the Mexico City metropolitan area from 2005 to 2006 were typed by using a PCR method based on genotype-specific primer amplification. Fifty isolates belonged to the E1 genotype, and the eleven remaining samples were classified as E2 genotypes. No coinfection with both E genotypes was identified among these specimens. We provide here new information on the distribution of VZV genotypes circulating in Mexico City.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/JCM.00112-10DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2863930PMC
May 2010

Genetic variation of Varicella-Zoster Virus strains circulating in Mexico City.

J Clin Virol 2009 Dec 13;46(4):349-53. Epub 2009 Oct 13.

Departamento de Genoma de Patógenos, Instituto de Diagnóstico y Referencia Epidemiológicos, Secretaría de Salud, Mexico City, Mexico.

Background: Different studies regarding VZV genotype distribution worldwide have demonstrated that genetic diversity and epidemiology of infection significantly vary from region to region. In Mexico, VZV genotype distribution is largely unknown mostly due to the lack of a surveillance system that monitors accurately the presence of viral strains circulating in the country.

Objective: To identify the main VZV genotypes circulating in the metropolitan area of Mexico City.

Study Design: In this study, 127 different VZV isolates, obtained from residents of the Mexico City Metropolitan area from 2005 to 2008, were identified and genotyped. Viral detection and preliminary genotyping was performed by amplification of the VZV ORF-38 and -54 and RFLP analysis using PstI and BglI endonuclease restriction patterns, respectively. Genotype was confirmed by nucleotide sequence variation along the ORF-22.

Results: RFLP analysis classified 121 viral strains as European and 6 as mosaic genotype. Genotyping scheme based on the ORF-22 sequence variation identified 120 viral strains belonging to the E genotype, 6 M1 and 1 M4 genotype strains.

Conclusions: VZV European genotype appears to predominate in Mexico City. This is the first study addressing VZV genotype distribution in Mexico. The information reported in this paper may be useful for future epidemiological studies conducted in the country and also contributes to understand better the molecular epidemiology of VZV in the Americas.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcv.2009.09.004DOI Listing
December 2009

Seroprevalence of Trypanosoma cruzi among Teenek Amerindian residents of the Huasteca region in San Luis Potosi, Mexico.

Am J Trop Med Hyg 2009 Aug;81(2):219-22

Laboratorio Estatal de Salud Pública de San Luis Potosí, Servicios de Salud de San Luis Potosí, Mexico, San Luis Potosí, Mexico.

Scarce information on the seroprevalence of Trypanosoma cruzi among Amerindians is available, and the distribution of this disease in Mexican Indian populations is unknown. In this study, the presence of specific antibodies against T. cruzi among Teenek Amerindians in nine different communities located in San Luis Potosi State was analyzed. An average seroprevalence of 6.5% was found in these populations, suggesting that active transmission of disease occurs in this relatively isolated population in Mexico, and therefore, further studies should be conducted to identify risk factor associated to Chagas disease in other isolated populations across the country to determine the prevalence of Chagas disease in Mexican Amerindians.
View Article and Find Full Text PDF

Download full-text PDF

Source
August 2009

Monoarthritis of the knee with unusual lesions in adults associated with varicella-zoster virus infection.

Arthroscopy 2009 Jan 26;25(1):106-8. Epub 2007 Nov 26.

Hospital de Ortopedia Victorio de la Fuente Narváez, Unidad de Medicina de Alta Especialidad Magdalena de las Salinas, Instituto Mexicano del Seguro Social, Mexico City, Mexico.

Varicella-zoster virus-associated arthritis has not been well documented in adults. We present the case of a 27-year-old female patient with monoarthritis of the knee associated with clinical symptoms typical of varicella. Arthroscopic examination showed unusual oval and circular lesions in cartilage, some of which measured 5 +/- 3 mm in diameter in weight-supporting zones. Such lesions have not been described previously and were type III-A lesions on the Noyes scale or grade IV on the Outerbridge scale. On microscopic observation, synovial fluid cultures and hemocultures were negative for the presence of bacteria. A biopsy sample and synovial liquid from the affected knee produced a positive polymerase chain reaction for varicella-zoster virus, genotype E. These findings suggest a strong relation between clinical varicella infection and important lesion invasion in the knee articulation of such a young adult, probably related to the virus. However, it remains necessary to corroborate this relation between cartilage destruction and clinical symptoms of varicella associated with monoarthritis of an adult knee. Nevertheless, it is advisable to initiate the appropriate antiviral treatment in adults with varicella-related gonalgia because the lesions produce the most severe effects on exposure to the knee bone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.arthro.2007.08.022DOI Listing
January 2009