Resistance phenotype and virulence potential of Leclercia adecarboxylata strains isolated from different sources.

Introduction. Leclercia adecarboxylata is a member of Enterobacterales, often considered an opportunistic pathogen. Recent reports have highlighted L. adecarboxylata as an emerging pathogen harbouring virulence and resistance determinants.Gap statement. Little information exists on virulence and resistance determinants in L. adecarboxylata strains isolated from environmental, food, and clinical samples.Aim. To determine the presence of resistance and virulence determinants and plasmid features in L. adecarboxylata strains isolated from environmental, food, and clinical samples, as well as their phylogenetic relationship.Results. All strains tested showed resistance to ß-lactams and quinolones but were sensitive to aminoglycosides and nitrofurans. However, even though fosfomycin resistance is considered a characteristic trait of L. adecarboxylata, the resistance phenotype was only observed in 50 % of the strains; bla TEM was the most prevalent BLEE gene (70 %), while the quinolone qnrB gene was observed in 60 % of the strains. Virulence genes were differentially observed in the strains, with adhesion-related genes being the most abundant, followed by toxin genes. Finally, all strains carried one to seven plasmid bands ranging from 7 to 125 kbps and harboured several plasmid addiction systems, such as ParDE, VagCD, and CcdAB in 80 % of the strains.Conclusions. L. adecarboxylata is an important emerging pathogen that may harbour resistance and virulence genes. Additionally, it has mobilizable genetic elements that may contribute to the dissemination of genetic determinants to other bacterial genera.

[Mixed analysis of the satisfaction survey of the Primary Health Care course of the Institute of Health for Well-being]. / Análisis mixto de la encuesta de satisfacción del curso de Atención Primaria de Salud del Instituto de Salud para el Bienestar.

Background: Describing the perception towards the online course on Primary Health Care (PHC) of the Institute of Health for Well-being (INSABI) will allow to establish improvement actions. Objective: Describe the factors that contribute to satisfaction with the PHC course offered online by INSABI. Material and methods: 620 records of the Health Education System for Well-being were studied. Satisfaction was determined using a Likert-type questionnaire with three dimensions: virtual environment, cognitive area, and measurement of learning. A deductive analysis of the open opinions was carried out. Results: 70% of the health personnel approved the course in less than a week, with an initial score of 5.41 ±1.9 points and final score of 7.8 ± 1.2. More than 65% had scores above the average in the three dimensions. Satisfaction with the virtual environment was 15.57 ± 3.4 points, and 15.73 ± 3.3 with the cognitive dimension. Age and gender were associated with dissatisfaction with the virtual environment and in the cognitive dimension, age was associated with dissatisfaction; 27.7% expressed negative comments, 28.5% related to course extension; 15.5% about the didactic techniques, 10.9% about the speakers and 10.4% about the final exam. Conclusions: The course generates significant learning, 62.4% of the students have a positive or neutral opinion. However, 27.8% expressed dissatisfaction, the majority related to the extension of the course.

Introducción: describir la percepción hacia el curso en línea de Atención Primaria de Salud (APS) del Instituto de Salud para el Bienestar (INSABI) permitirá establecer acciones de mejora. Objetivo: conocer el grado de satisfacción con el curso sobre APS que el INSABI ofrece en línea mediante un análisis mixto. Material y métodos: se estudiaron 620 registros del Sistema Educativo de Salud para el Bienestar. La satisfacción se determinó mediante un cuestionario tipo Likert con tres dimensiones: ambiente virtual, área cognitiva y medición del aprendizaje. Se realizó un análisis deductivo de las opiniones abiertas. Resultados: el 70% de los trabajadores de la salud aprobaron el curso en menos de una semana con una calificación inicial de 5.41 ± 1.9 puntos y la final de 7.8 ± 1.2. Más del 65% tuvieron puntuaciones por arriba de la media en las tres dimensiones. La satisfacción con el ambiente virtual fue de 15.57 ± 3.4 puntos, y de 15.73 ± 3.3 con la dimensión cognitiva. La edad y el sexo se asociaron a insatisfacción con el ambiente virtual y en la dimensión cognitiva, la edad se asoció con insatisfacción; el análisis cualitativo mostró que 27.7% expresaron comentarios negativos, 28.5% relacionadas con la extensión del curso; 15.5% sobre las técnicas didácticas, 10.9% acerca de los ponentes y 10.4% sobre el examen final. Conclusiones: el curso genera aprendizaje significativo, el 62.4% de los educandos tienen una opinión positiva o neutra. Sin embargo, 27.8% manifestaron insatisfacción, la mayoría relacionada con la extensión del curso.

[Development of the INSABI educational strategy: a lesson learned from the COVID-19 epidemic]. / Desarrollo de la estrategia educativa del INSABI: una lección aprendida a partir de la epidemia de COVID-19.

The Institute for Health for Well-being (INSABI according to its initials in Spanish), in collaboration with the National Institute of Medical Sciences and Nutrition Salvador Zubirán (INCMNSZ), instituted the Continuous Training on clinical management "Mexico against COVID-19" in 2020, with the purpose of training the frontline health personnel in the care for patients with COVID-19 in the context of hospital reconversion through the COVIDUTI platform. Virtual conferences were held for medical personnel from all over the country with the possibility of interacting with various specialists. In 2020, 215 sessions were held and 158 in 2021. That year educational content was expanded and included topics for other health categories, such as nursing and social work. In October 2021, it was established the Health Educational System for Well-being (SIESABI), with the aim of promoting continuous and permanent education for health workers. It currently offers face-to-face and virtual courses, permanent seminars, and telementoring, with the possibility of providing academic follow-up to its subscribers and linking priority courses that are on other platforms. The educational platform is an opportunity to unify the efforts of the health system in Mexico in the continuous and permanent education of professionals who care for people without social security and thereby contribute to the implementation of a model of care based on primary health care (PHC).

El Instituto de Salud para el Bienestar (INSABI), en colaboración con el Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ), instituyó el entrenamiento continuo sobre manejo clínico "México contra COVID-19" en 2020, con el propósito de capacitar al personal de salud de primera línea en la atención de pacientes con COVID-19 en el contexto de la reconversión hospitalaria mediante la plataforma COVIDUTI. Se realizaron conferencias virtuales dirigidas a personal médico de todo el país con la posibilidad de interactuar con diversos especialistas. En 2020 se realizaron 215 sesiones y 158 en 2021. Ese año se ampliaron contenidos educativos y se incluyeron temas para otras categorías de salud, como enfermería y trabajo social. En octubre de 2021 se estableció el Sistema Educativo de Salud para el Bienestar (SIESABI), con el objetivo de promover la educación continua y permanente para los trabajadores de la salud. Actualmente ofrece cursos presenciales, virtuales, seminarios permanentes y telementorías, con la posibilidad de dar seguimiento académico a sus suscriptores y vincular cursos prioritarios que están en otras plataformas. La plataforma educativa es una oportunidad para unificar los esfuerzos del sistema de salud en México en la educación continua y permanente de los profesionales que atienden a personas sin seguridad social y, con ello, contribuir en la implementación de un modelo de atención basado en Atención Primaria de Salud (APS).

Genomic insights of Leclercia adecarboxylata strains linked to an outbreak in public hospitals in Mexico.

BACKGROUND: Leclercia adecarboxylata is a bacteria closely related to Escherichia coli according to its biochemical characteristics and is commonly considered non-pathogenic although a growing number of publications classify it as an emerging pathogen. Fosfomycin resistance is a common trait for L. adecarboxylata encoded by fosALA gene. OBJECTIVE: To analyze genomic traits of sixteen L. adecarboxylata strains isolated from blood culture and a bottle of total parenteral nutrition. METHODS: Twenty-eight L. adecarboxylata strains isolated from blood culture and a bottle of total parenteral nutrition were identified biochemically with a Vitek ® automated system. The strains were phenotyped by their growth on Eosin Methylene Blue agar or MacConkey agar plates. Additionally, Pulsed field gel electrophoresis (PFGE) was performed to establish the clonal relationship. The genomic DNA of sixteen strains was obtained using a Qubit ® dsDNA HS Assay Kit and sequenced on an Illumina ® MiSeq instrument. Draft genomes were assembled using PROKKA and Rast. Assemblies were submitted to Resfinder and PathogenFinder from the Center for Genomic Epidemiology in order to find resistance genes and pathogenic potential. IslandViewer4 was also used to find Pathogenicity and Phage Islands. For identification of the fosA gene, manual curation and Clustal analysis was performed. A novel FosA variant was identified. Finally, phylogenetic analysis was performed using VAMPhyRE software and Mega X. RESULTS: In this paper, we report the genomes of sixteen strains of Leclercia adecarboxylata causing an outbreak associated with parenteral nutrition in public hospitals in Mexico. The genomes were analyzed for genetic determinants of virulence and resistance. A high pathogenic potential (pathogenicity index 0.82) as well as multiple resistance genes including carbapenemics, colistin and efflux pumps were determined. Based on sequence analysis, a new variant of the fosALA gene was described. Finally, the outbreak was confirmed by establishing the clonal relationship among the sixteen genomes obtained. CONCLUSIONS: Commensal strains of L. adecarboxylata may acquire genetic determinants that provide mechanisms of host damage and go unnoticed in clinical diagnosis. L. adecarboxylata can evolve in a variety of ways including the acquisition of resistance and virulence genes representing a therapeutic challenge in patient care.

Genetic diversity and spatiotemporal dynamics of DENV-1 and DENV-2 infections during the 2012-2013 outbreak in Mexico.

Dengue fever is caused by four related dengue virus serotypes, DENV-1 to DENV-4, where each serotype comprises distinct genotypes and lineages. The last major outbreak in Mexico occurred during 2012 and 2013, when 112,698 confirmed cases were reported (DENV-1 and DENV-2 were predominant). Following partial E, NS2A and NS5 gene sequencing, based on the virus genome variability, we analyzed 396 DENV-1 and 248 DENV-2 gene sequences from serum samples from dengue acute clinical cases from 13 Mexican states, Mutations were identified, and their genetic variability estimated, along with their evolutionary relationship with DENV sequences sampled globally. DENV-1 genotype V and DENV-2 Asian-American genotype V were the only genotypes circulating during the outbreak. Mutations in NS2A and NS5 proteins were widely disseminated and suggested local emergence of new lineages. Phylogeographic analysis suggested viral spread occurred from coastal regions, and tourist destinations, such as Yucatan and Quintana Roo, which played important roles in disseminating these lineages.

Partial in vivo protection against Peruvian spider Loxosceles laeta venom by immunization with a multiepitopic protein (rMEPLox).

Loxoscelism is a serious public health problem in Peru, with approximately 2500 accidents reported per year. To envision alternatives to cope with this health problem, the neutralizing humoral immune response against the lethal effects of Peruvian spider Loxosceles laeta venom was evaluated in a mouse model by immunization with a non-toxic multiepitopic protein (rMEPLox). This immunogen contains epitopes from an astacin-like metalloprotease, a hyaluronidase and a sphingomyelinase-D from Loxosceles intermedia and from SMase-I from L. laeta venoms. In vivo protection assays showed that five out of six mice immunized with rMEPLox (after six injections) resisted to 1.4 LD50 of L. laeta venom, whereas only two animals from a control group survived. The present results indicates that this multiepitopic protein can be a promising candidate for anti-loxoscelic antivenom production and experimental vaccination approaches.

Low Prevalence of ETV6::RUNX1 Fusion Gene in a Hispanic Population.

ETV6::RUNX1 is a genetic rearrangement of good prognosis in children with acute lymphoblastic leukemia (ALL). In Mexico, its prevalence is low in comparison with Caucasian populations. We developed a novel TaqMan one-step RT-qPCR approach to assess the prevalence of four genetic rearrangements in a cohort of Hispanic children with ALL from Mexico City. The prevalence of common fusion gene transcripts was as follows: TCF3::PBX1 7.7%; BCR::ABL1p 190 3.3%; and KMT2A::AFF1 2.8%, and ETV6::RUNX1was observed with low prevalence (10.5%) in comparison to that reported for developed countries. This is consistent with previous findings on Mexican children with ALL and similar to those reported on children from Hispanic populations. The confirmation of a low prevalence of ETV6::RUNX1 in children of a Hispanic origin represents an advancement in the description of genetic factors of ALL in these populations.

Morphological and molecular characterization of a new autochthonous Trichoderma sp. isolate and its biocontrol efficacy against Alternaria sp.

The development of agriculture requires the use of microorganisms in the management of phytopathogens as a way to compensate for the use of chemical pesticides, in order to produce healthy crops. The objective of this study was to characterize a new isolate of Trichoderma sp. based on morphological and molecular features, and its potential ability to control the pathogen Alternaria sp. The antagonistic isolate was isolated from soil samples of potato fields in Guasave Sinaloa, Mexico, whereas the pathogen was collected from infected apple leaves in the orchard "La Escondida" in Guerrero County, Chihuahua, Mexico. For morphological characterization both fungi were grown on solid PDA medium. DNA of Trichoderma sp. was isolated using the CTAB method and PCR analyses were done using ITS1, ITS4 primers resulting in amplified products of 600 bp. These were sequenced, submitted to Genbank (acc. no. MN950427) and used for further phylogenetic analysis through Bayesian inference approach. Five clades were identified and the polytome topography recovered from clade 4 indicates a high genetic similarity with T. asperellum. A BLAST examination of the resulting sequence in GenBank showed 98.11% similarity with T. asperellum. This result together with the morphological and the phylogenetic analyses indicates that the isolate belongs to Trichoderma asperellum Samuels, Lieckfeldt & Nirenberg. Biocontrol tests of this isolate showed inhibition of Alternaria sp. between 50% and 93%. These results are essential for biodiversity research and give some new possibilities for pest management.

A Multimodal Strategy to Reduce the Risk of Hospitalization/death in Ambulatory Patients with COVID-19.

BACKGROUND: Different interventions have been implemented worldwide for the house-hold monitoring of patients with mild COVID-19 to reduce the burden of healthcare systems and guarantee quality of care. Telephone follow up and treatment kits have not been evaluated in the context of a national-wide primary care program. AIM OF THE STUDY: To compare the risk of hospitalization and death for COVID-19 between ambulatory patients who received and those who did not receive a treatment kit and telephone follow-up in a developing country METHODS: A two-group comparative analysis was conducted using data from the medical information systems of the Mexican Institute of Social Security. We included a total of 28,048 laboratory-confirmed SARS-CoV-2 patients: 7,898 (28.2%) received a medical kit and 20,150 (71.8%) did not. The incidence rates of hospitalization and death combined were calculated. To identify significant associations between hospitalization or death and treatment medical kits, we calculated the risk ratios using a multivariate logistic model. RESULTS: The incidence of hospitalization was 6.14% in patients who received a kit and 11.71% in those who did not. Male sex, age, and a medical history of obesity, hypertension, diabetes, immunosuppression, or kidney disease were associated with increased risk of hospitalization or death. The risk rates were reduced in patients who received a medical kit or telephone follow-up. In the multivariate model, receiving a medical kit was associated with a lower risk of hospitalization or death from COVID-19: adjusted risk ratio 0.41 (95% confidence interval 0.36-0.47). CONCLUSION: Use of a multimodal strategy may reduce the risk of hospitalization and death in adult outpatients with mild COVID-19.

Rehabilitation of Marine Turtles and Welfare Improvement by Application of Environmental Enrichment Strategies.

Sea turtles perform various ecological services in several marine environments and are considered architects of the marine landscape. At present, they are endangered species due to anthropogenic threats, pollution and degradation of marine habitats. These impacts make it urgent to increase protection and conservation efforts. Protective actions include the rescue and rehabilitation of injured individuals as a result of their interactions with humans and other threats. Environmental enrichment (EE) is a series of techniques and methods aimed to improve the welfare of animals in captivity and/or under rehabilitation. It uses external stimuli to enhance their psychological and physiological wellbeing to promote natural abilities and behaviors. These may increase the survival chances of rehabilitated animals upon release in the wild. This review presents data of studies where EE has been applied during the rehabilitation processes of different species of sea turtles, and its effect on welfare improvement during captivity/rehabilitation and on survival after release into nature. Technologies such as satellite tags are an important means to determine rehabilitation success and survival of injured individuals from endangered species after release into the wild, as they allow tracking and monitoring of such individuals, and determine their location in areas used by their natural populations for feeding or breeding.

Genomic signatures of pre-resistance in Mycobacterium tuberculosis.

Recent advances in bacterial whole-genome sequencing have resulted in a comprehensive catalog of antibiotic resistance genomic signatures in Mycobacterium tuberculosis. With a view to pre-empt the emergence of resistance, we hypothesized that pre-existing polymorphisms in susceptible genotypes (pre-resistance mutations) could increase the risk of becoming resistant in the future. We sequenced whole genomes from 3135 isolates sampled over a 17-year period. After reconstructing ancestral genomes on time-calibrated phylogenetic trees, we developed and applied a genome-wide survival analysis to determine the hazard of resistance acquisition. We demonstrate that M. tuberculosis lineage 2 has a higher risk of acquiring resistance than lineage 4, and estimate a higher hazard of rifampicin resistance evolution following isoniazid mono-resistance. Furthermore, we describe loci and genomic polymorphisms associated with a higher risk of resistance acquisition. Identifying markers of future antibiotic resistance could enable targeted therapy to prevent resistance emergence in M. tuberculosis and other pathogens.

Structural Characterization of Haemophilus influenzae Enolase and Its Interaction with Human Plasminogen by In Silico and In Vitro Assays.

Haemophilus influenzae is the causal agent of invasive pediatric diseases, such as meningitis, epiglottitis, pneumonia, septic arthritis, pericarditis, cellulitis, and bacteremia (serotype b). Non-typeable H. influenzae (NTHi) strains are associated with localized infections, such as otitis media, conjunctivitis, sinusitis, bronchitis, and pneumonia, and can cause invasive diseases, such as as meningitis and sepsis in immunocompromised hosts. Enolase is a multifunctional protein and can act as a receptor for plasminogen, promoting its activation to plasmin, which leads to the degradation of components of the extracellular matrix, favoring host tissue invasion. In this study, using molecular docking, three important residues involved in plasminogen interaction through the plasminogen-binding motif (251EFYNKENGMYE262) were identified in non-typeable H. influenzae enolase (NTHiENO). Interaction with the human plasminogen kringle domains is conformationally stable due to the formation of four hydrogen bonds corresponding to enoTYR253-plgGLU1 (K2), enoTYR253-plgGLY310 (K3), and enoLYS255-plgARG471/enoGLU251-plgLYS468 (K5). On the other hand, in vitro assays, such as ELISA and far-western blot, showed that NTHiENO is a plasminogen-binding protein. The inhibition of this interaction using polyclonal anti-NTHiENO antibodies was significant. With these results, we can propose that NTHiENO-plasminogen interaction could be one of the mechanisms used by H. influenzae to adhere to and invade host cells.

Limitación del esfuerzo terapéutico al final de la vida: una mirada desde la medicina cubana contemporánea / Limitation of the Therapeutic Effort At the End of Life: A View from Contemporary Cuban Medicine

Los dilemas éticos respecto al cuidado al final de la vida son los más delicados e importantes en la práctica médica contemporánea; rebasan el campo de la bioética por sus implicaciones legales, sociales, culturales y religiosas. Independientemente de la universalidad de los postulados bioéticos, estos deben ser contextualizados atendiendo las características propias de cada nación. El panorama demográfico y epidemiológico de Cuba hace que la problemática tenga un comportamiento similar al mundo desarrollado, lo cual nos motivó a realizar un acercamiento teórico a la práctica de la limitación del esfuerzo terapéutico. Para ello partimos de los principios éticos de la nacionalidad cubana, el escenario social-demográfico, el marco legal vigente y la política de salud en el contexto de las transformaciones económicas que vive el país. Esa estrategia terapéutica no guarda relación alguna con la eutanasia y permite retirar del escenario clínico la distanasia. A la vez, constituye un punto de partida hacia los cuidados paliativos con impacto en lo económico y en el ordenamiento eficiente de los servicios de salud potencialmente beneficioso. Existe en la literatura nacional un movimiento favorable respecto a esa práctica médica; pero la principal debilidad en el país es la falta de un marco legal que condene la distanasia y reconozca la limitación del esfuerzo terapéutico como la medida que la evita(AU)

Ethical dilemmas regarding end-of-life care are the most delicate and important in contemporary medical practice; this care goes beyond the field of bioethics due to legal, social, cultural and religious implications. Regardless of the universality of bioethical postulates, they must be contextualized taking into account the characteristics of each nation. The demographic and epidemiological panorama of Cuba makes the problem behave similarly to the developed world, which motivated us to make a theoretical approach to the practice of limiting the therapeutic effort. For this purpose, we start from the ethical principles of Cuban nationality, the social-demographic scenario, the current legal framework and the health policy in the context of the economic transformations that the country is experiencing. This therapeutic strategy is not related to euthanasia and it allows dysthanasia to be removed from the clinical setting. At the same time, it constitutes a starting point towards palliative care with an economic impact and in the efficient organization of potentially beneficial health services. There is a favorable movement in the national literature regarding this medical practice; but the main weakness in the country is the lack of a legal framework that condemns dysthanasia and it recognizes the limitation of therapeutic effort as the measure that avoids it(AU)

Spatial and Temporal Genetic Diversity and Population Structure of Hemileia vastatrix from Peruvian Coffee Plantations.

Population genetic studies of Hemileia vastatrix have been conducted in order to describe the evolutionary dynamics of the pathogen and the disease epidemiology as consequence of changes in disease management and host distribution occurred in Peru after the 2013 epidemic. These analyses were performed by sequencing the internal transcribed spacers of the nuclear ribosomal DNA (rDNA-ITS) of H. vastatrix collected from two coffee growing areas in 2014 and 2018. H. vastatrix population showed high haplotype diversity (Hd = 0.9373 ± 0.0115) with a low nucleotide diversity (π = 0.00322 ± 0.00018). Likewise, AMOVA indicated that fungus population has behaved as a large population without structuring by geographical origin and sampling years (FST = 0.00180, P = 0.20053 and FST = 0.00241, P = 0.19693, respectively). Additionally, the haplotype network based on intraspecific phylogenetic analysis of H. vastatrix using Peruvian and NCBI sequences revealed that Peruvian ancestral haplotypes, which were maintained in time and space, would correspond to the reported sequences of the races II and XXII. This result suggests that no substantial changes have occurred through time in Peruvian Hemileia vastatrix population.

Mini Review: Virus Interference: History, Types and Occurrence in Crustaceans.

Virus interference is a phenomenon in which two viruses interact within a host, affecting the outcome of infection of at least one of such viruses. The effect of this event was first observed in the XVIII century and it was first recorded even before virology was recognized as a distinct science from microbiology. Studies on virus interference were mostly done in the decades between 1930 and 1960 in viruses infecting bacteria and different vertebrates. The systems included in vivo experiments and later, more refined assays were done using tissue and cell cultures. Many viruses involved in interference are pathogenic to humans or to economically important animals. Thus the phenomenon may be relevant to medicine and to animal production due to the possibility to use it as alternative to chemical therapies against virus infections to reduce the severity of disease/mortality caused by a superinfecting virus. Virus interference is defined as the host resistance to a superinfection caused by a pathogenic virus causing obvious signs of disease and/or mortality due to the action of an interfering virus abrogating the replication of the former virus. Different degrees of inhibition of the superinfecting virus can occur. Due to the emergence of novel pathogenic viruses in recent years, virus interference has recently been revisited using different pathogens and hosts, including commercially important farmed aquatic species. Here, some highly pathogenic viruses affecting farmed crustaceans can be affected by interference with other viruses. This review presents data on the history of virus interference in hosts including bacteria and animals, with emphasis on the known cases of virus interference in crustacean hosts. Life Science Identifiers (LSIDs) Escherichia coli [(Migula 1895) Castellani & Chalmers 1919] Aedes albopictus (Skuse 1894) Liocarcinus depurator (Linnaeus 1758): urn:lsid:marinespecies.org:taxname:107387 Penaeus duorarum (Burkenroad 1939): urn:lsid:marinespecies.org:taxname:158334 Carcinus maenas (Linnaeus 1758): urn:lsid:marinespecies.org:taxname:107381 Macrobrachium rosenbergii (De Man 1879): urn:lsid:marinespecies.org:taxname:220137 Penaeus vannamei (Boone 1931): urn:lsid:zoobank.org:pub:C30A0A50-E309-4E24-851D-01CF94D97F23 Penaeus monodon (Fabricius 1798): urn:lsid:zoobank.org:act:3DD50D8B-01C2-48A7-B80D-9D9DD2E6F7AD Penaeus stylirostris (Stimpson 1874): urn:lsid:marinespecies.org:taxname:584982.

SARS-CoV-2 IgG Antibodies Seroprevalence and Sera Neutralizing Activity in MEXICO: A National Cross-Sectional Study during 2020.

Until recently, the incidence of COVID-19 was primarily estimated using molecular diagnostic methods. However, the number of cases is vastly underreported using these methods. Seroprevalence studies estimate cumulative infection incidences and allow monitoring of transmission dynamics, and the presence of neutralizing antibodies in the population. In February 2020, the Mexican Social Security Institute began conducting anonymous unrelated sampling of residual sera from specimens across the country, excluding patients with fever within the previous two weeks and/or patients with an acute respiratory infection. Sampling was carried out weekly and began 17 days before Mexico's first officially confirmed case. The 24,273 sera obtained were analyzed by chemiluminescent-linked immunosorbent assay (CLIA) IgG S1/S2 and, later, positive cases using this technique were also analyzed to determine the rate of neutralization using the enzyme-linked immunosorbent assay (ELISA). We identified 40 CLIA IgG positive cases before the first official report of SARS-CoV-2 infection in Mexico. The national seroprevalence was 3.5% in February and 33.5% in December. Neutralizing activity among IgG positives patients during overall study period was 86.1%. The extent of the SARS-CoV-2 infection in Mexico is 21 times higher than that reported by molecular techniques. Although the general population is still far from achieving herd immunity, epidemiological indicators should be re-estimated based on serological studies of this type.

Cardiotoxic Effects of Micrurus surinamensis (Cuvier, 1817) Snake Venom.

Micrurus surinamensis is a coral snake from the Elapidae family of wide distribution in Amazonia Forest. Its venom contains neurotoxins that induce muscular and respiratory paralysis; however, its cardiovascular action is not yet characterized. The aim of this study was to investigate the cardiotoxic effects caused by M. surinamensis poisoning in rodents. Twelve guinea pigs (Cavia porcellus) were distributed in two groups (n = 6) named as control and envenomed. The control group received 0.2 ml of PBS/BSA via intramuscular injection (IM), while envenomed animals received 0.75 µg of venom per g of body weight, also via IM. Electrocardiographic examination (ECG) and biochemical serum tests were conducted before and 2 h after inoculation. ECG of the envenomed animals revealed severe progressive arrhythmias including atrioventricular block, supraventricular, and ventricular extrasystoles. Serum biochemistry showed significant increase in CK, CK-MB, and LDH enzymes corroborating the skeletal and cardiac muscle damage. Myonecrosis and degeneration were observed in both skeletal and heart muscle; nevertheless, transmission electron microscopy revealed cardiac muscle fibers fragmentation. In conclusion, M. surinamensis venom has a potent cardiotoxic activity eliciting arrhythmogenic effects and heart damage after only 2 h of envenomation.

Pregnant Women Infected with Zika Virus Show Higher Viral Load and Immunoregulatory Cytokines Profile with CXCL10 Increase.

BACKGROUND: Zika virus (ZIKV) infection during pregnancy usually shows only mild symptoms and is frequently subclinical. However, it can be vertically transmitted to the fetus, causing microcephaly and other congenital defects. During pregnancy, the immune environment modifications can alter the response to viruses in general and ZIKV in particular. OBJECTIVE: To describe the role of pregnancy in the systemic pro- and anti-inflammatory response during symptomatic ZIKV infection. MATERIALS AND METHODS: A multiplex assay was used to measure 25 cytokines, chemokines, and receptors in 110 serum samples from pregnant and nonpregnant women with and without ZIKV infection with and without symptoms. Samples were collected through an epidemiological surveillance system. RESULTS: Samples from pregnant women with ZIKV infection showed a higher viral load but had similar profiles of inflammatory markers as compared with nonpregnant infected women, except for CXCL10 that was higher in infected pregnant women. Notably, the presence of ZIKV in pregnancy favored a regulatory profile by significantly increasing anti-inflammatory cytokines such as interleukin (IL)-10, receptors IL-1RA, and IL-2R, but only those pro-inflammatory cytokines such as IL-6, interferon (IFN)-α, IFN-γ and IL-17 that are essential for the antiviral response. Interestingly, there were no differences between symptomatic and weakly symptomatic ZIKV-infected groups. CONCLUSION: Our results revealed a systemic anti-inflammatory cytokine and chemokine profile that could participate in the control of the virus. The anti-inflammatory response in pregnant women infected with ZIKA was characterized by high CXCL10, a cytokine that has been correlated with congenital malformations.