Evaluating low and high vitamin D levels in Ecuadorian cities from 2018 to 2022: interrupted time series and a cross-sectional study.

OBJECTIVES: To identify differences in the mean vitamin D concentrations in samples obtained from a private laboratory in Quito and to explore their relationship with the pre-pandemic and pandemic periods spanning from 2018 to 2022. DESIGN: A combination of an interrupted time series design and a retrospective cross-sectional approach. SETTING AND PARTICIPANTS: The study involved 9285 participants who had their 25-hydroxyvitamin D (25(OH)D) levels tested at a well-known private laboratory in Quito, Ecuador, from 2018 to 2022. PRIMARY AND SECONDARY OUTCOME MEASURES: The 25(OH)D levels were analysed and assessed for correlations with age, and the year the measurements were taken. RESULTS: The mean 25(OH)D level was 27.53 ng/mL (± 14.11). Approximately 68.8% of participants had serum 25(OH)D levels of less than 30 ng/mL, and 0.6% showed potential harm from excess 25(OH)D, with levels over 100 ng/mL. The analysis indicated a significant monthly increase of 0.133 units in 25(OH)D levels (p=0.006). However, the period after March 2020, compared with before, saw a non-significant decrease of 1.605 units in mean 25(OH)D levels (p=0.477). CONCLUSIONS: The study's findings indicate a significant prevalence of 25(OH)D deficiency, underscoring the necessity for preventative measures. However, the increasing trend in high 25(OH)D levels is concerning, emphasising the importance of prudent vitamin D supplement prescriptions and public education against self-medication. For efficient resource allocation and targeting of those with higher risks, it may be advantageous to concentrate vitamin D testing on specific population groups.

First Report of Antibiotic Resistance Markers cfiA and nim Among Bacteroides fragilis Group Strains in Ecuadorian Patients.

In recent years, increasing resistance of Bacteroides fragilis to several antibiotics has been reported in different countries. The aim of this study was to evaluate the antibiotic resistance profiles of Bacteroides spp. isolated from clinical samples by phenotypic and molecular methods. A total of 40 nonrepetitive isolates of the B. fragilis group were studied from 2018 to 2019. The species was identified by API 20A system. The minimum inhibitory concentrations (MICs) were determined by Sensititre anaerobe MIC plate. The presence of the nim and cfiA genes was checked by conventional PCR. The association between genes and insertion sequence (IS) was performed by whole genome sequencing. Eleven isolates were categorized as metronidazole-resistant and only 2 isolates harbored the nim gene. Five isolates were imipenem-resistant, but cfiA gene was detected in two isolates. cfiA gene was closely related to the cfiA-4 allele and associated with IS614B. The nim gene was not related to any nim gene type and was considered a new variant named nimL. IS612 was found upstream of nimL gene. In view of the scarcity of data on B. fragilis, there is a need to surveil antibiotic resistance levels and molecular mechanisms to implement better antimicrobial therapies against this important group of bacteria.

Mutations associated with Helicobacter pylori antimicrobial resistance in the Ecuadorian population.

AIMS: We described the presence of Helicobacter pylori (HP) and estimated the prevalence of primary and secondary resistance using molecular detection in gastric biopsies of Ecuadorian patients. METHODS AND RESULTS: 66.7% (238/357) of the patients demonstrated the presence of HP using CerTest qPCR. Of these, 69.79% (104/149) were without previous HP eradication treatment and 64.42% (134/208) with prior HP eradication treatment. The mutation-associated resistance rate for clarithromycin was 33.64% (primary resistance) and 32.82% (secondary resistance), whereas that in levofloxacin the primary and secondary resistance was 37.38% and 42%, respectively. For tetracycline and rifabutin, primary and secondary resistance was 0%. Primary and secondary resistance for metronidazole and amoxicillin could not be evaluated by genotypic methods (PCR and sequencing). CONCLUSIONS: The analysis of mutations in gyrA, 23S rRNA and 16S rRNA is useful to detect bacterial resistance as a guide for eradication therapy following failure of the first-line regimen. SIGNIFICANCE AND IMPACT OF THE STUDY: This study carried out in an Ecuadorian population indicates that the resistance of HP to first-line antibiotics is high, which may contribute to the high rates of treatment failure, and other treatment alternatives should be considered.

Evidence of SARS-CoV-2 reinfection within the same clade in Ecuador: A case study.

OBJECTIVES: To date, reported SARS-CoV-2 reinfection cases are mainly from strains belonging to different clades. As the pandemic advances, a few lineages have become dominant in certain areas leading to reinfections by similar strains. Here, we report a reinfection case within the same clade of the initial infection in a symptomatic 28-year-old-male in Quito-Ecuador. METHODS: Infection was detected by reverse transcription-polymerase chain reaction, and immune response evaluated by antibody testing. Whole-genome sequencing was performed and phylogenetic analysis conducted to determine relatedness. RESULTS: Both the infection and the reinfection strains were assigned as Nextstrain 20B, Pangolin lineage B.1.1 and GISAID clade O. Our analysis indicated 4-6 fold more nucleotide changes than are expected for reactivation or persistence compared with the natural rate of SARS-CoV-2 mutation (∼2-3 nucleotide changes per month), thus supporting reinfection. Furthermore, approximately 3 months after the second infection, COVID-19 antibodies were not detectable in the patient, suggesting potential vulnerability to a third infection. CONCLUSIONS: Our results showed evidence of SARS-CoV-2 reinfection within the same clade in Ecuador, indicating that previous exposure to SARS-CoV-2 does not guarantee immunity in all cases.

A functional ABCA1 gene variant is associated with low HDL-cholesterol levels and shows evidence of positive selection in Native Americans.

It has been suggested that the higher susceptibility of Hispanics to metabolic disease is related to their Native American heritage. A frequent cholesterol transporter ABCA1 (ATP-binding cassette transporter A1) gene variant (R230C, rs9282541) apparently exclusive to Native American individuals was associated with low high-density lipoprotein cholesterol (HDL-C) levels, obesity and type 2 diabetes in Mexican Mestizos. We performed a more extensive analysis of this variant in 4405 Native Americans and 863 individuals from other ethnic groups to investigate genetic evidence of positive selection, to assess its functional effect in vitro and to explore associations with HDL-C levels and other metabolic traits. The C230 allele was found in 29 of 36 Native American groups, but not in European, Asian or African individuals. C230 was observed on a single haplotype, and C230-bearing chromosomes showed longer relative haplotype extension compared with other haplotypes in the Americas. Additionally, single-nucleotide polymorphism data from the Human Genome Diversity Panel Native American populations were enriched in significant integrated haplotype score values in the region upstream of the ABCA1 gene. Cells expressing the C230 allele showed a 27% cholesterol efflux reduction (P< 0.001), confirming this variant has a functional effect in vitro. Moreover, the C230 allele was associated with lower HDL-C levels (P = 1.77 x 10(-11)) and with higher body mass index (P = 0.0001) in the combined analysis of Native American populations. This is the first report of a common functional variant exclusive to Native American and descent populations, which is a major determinant of HDL-C levels and may have contributed to the adaptive evolution of Native American populations.

Collagen turnover is diminished by different clones of skin fibroblasts from early- but not late-stage systemic sclerosis.

To investigate collagen turnover and proliferation in dermal fibroblasts from patients with systemic sclerosis (SSc) and their relationship with disease duration and cellular subpopulations, SSc patients were grouped by disease duration (less than 2.5 years or more than 7 years). Control and SSc fibroblasts were obtained from skin biopsies. Collagen biosynthesis was determined by [14C]-proline uptake. Type I/III collagens, gelatinolytic activity, and tissue inhibitors of metalloproteinases (TIMP)-1 and -2 were evaluated by electrophoresis, zymography, and enzyme-linked immunosorbent assay, respectively. Total collagen synthesis and the levels of alpha1(I), alpha2(I), and alpha1(III) chains, as well as TIMP-1 and proliferation were increased in fibroblasts only from patients with early-stage SSc. Gelatinolytic activity did not vary among the groups. This metabolic condition favors a higher local fibroblast population and is characterized by a heterogeneous clonal response in which the majority exhibited higher levels of collagen and TIMP-1 synthesis as well as an increase in their proliferation patterns involving hyper-reactive fibroblast subsets.

Producción y caracterización de anticuerpos monoclonales específicos para la toxina de vibrio cholerae 01: informe preliminar

El vibrio cholerae es el agente causal de la enfermedad del cólera. El serotipo 01 puede ser subdividido en los biotipos el tor y clásico. En el diagnóstico de la enfermedad del cólera se utilizan kits comerciales con el uso de anticuerpos monoclonales (AM), éstos existen a nivel mundial, pero el país no cuenta todavía con un centro de elaboración y mantenimiento de producción de AM, por lo que se propuso la creación de un centro de elaboración de anticuerpos monoclonales. En este informe preliminar mencionamos la producción y caracterización de AM contra la toxina colérica (TC) para lo que se utilizó como antígeno el extracto total del V. cholerae 01 (AC). La purificación se realizó mediante cromatografía de afinidad...

Spontaneous cytokine gene expression by cultured skin fibroblasts of systemic sclerosis. Correlation with collagen synthesis

Objetivo. Investigar la expresión espóntanea de los genes de citocinas en fibroblastos de pacientes con esclerosis generalizada progresiva y correlacionarla con la producción de colágena. Métodos. Los fibroblastos se obtuvieron de biopsias de piel de nueve pacientes con diagnóstico de esclerosis generalizada progresiva (duración de la enfermedad, media 16 ñ 8.7 años) y diez sujetos controles. La expresión de los genes de citocinas fue detectada mediante transcriptasa reversa seguida de la reacción en cadena de polimerasa para las interleucinas (IL) IL-1 beta, IL-6, IL-8, factor de necrosis tumoral-alfa, factor transformador de crecimiento-beta. Además, se midió la síntesis de colágena mediante incorporación de prolina [14C] en los cultivos de fibroblastos. Resultados. Todos los fibroblastos de pacientes expresaron el gen de la IL-8 (p=0.02 comparado con los controles). Cuatro de ellos expresaron el gen del factor transformador de crecimiento-beta y dos expresaron débilmente el gen del factor de necrosis tumoral-alfa. Solamente un paciente expresó el gen de la IL-1 beta. La producción de colágena fue mayor en fibroblastos de pacientes con esclerosis generalizada progresiva (p=0.028) comparados con los controles. Hubo correlación entre la expresión de los genes de la IL-6 y la producción de colágena (rs=1). Conclusiones. La mayor expresión constitutiva de los genes de la IL-6 y de la IL-8 por los fibroblastos puede desempeñar un papel importante en la perpetuación de la regulación inmune alterada y en la activación permanente del fibroblasto en sitio de lesión de los pacientes con esclerosis generalizada progresiva de larga evolución

Apoptosis en infección bacteriana in vitro / Apoptosis in in vivo bacterial infection

La muerte celular programada o apoptosis es un mecanismo importante en la homeostasis y desarrollo de organismos multicelulares. La necrosis y la apoptosis son dos formas de muerte celular; la primera es un proceso pasivo, en contrarse con la segunda, que es un proceso activo, resultado de un programa genético; estos dos tipos de muerte también se distinguen por cambios morfológicos. Hay evidencias de que existe un programa genético de la muerte celular programada, y el nematodo Caenorhabditis elegans ha sido el instrumento para demostrarlo. Hay genes que son necesarios para inhibir o bloquear la apoptosis y se han identificado por lo menos doce. También otras moléculas son indispensables para inducir la apoptosis y, recientemente, se ha demostrado que las bacterias puedan provocar la apoptosis. A pesar de que en las células huésped no se ha demostrado la expresión o inhibición de algún gen, se han propuesto cuatro modelos hipotéticos para que las bacterias y/o toxinas induzcan apoptosis en las células huésped, a saber: activación o mimetización de segundos mensajeros, efecto directo tóxico y que el microorganismo interfiera con señales constitutivas de sobrevivencia. La primera bacteria implicada fue la Shigella flexneri, causante de disentería, cuyos mecanismos de activación no se conocen, aunque se han propuesto por lo menos tres. También se ha demostrado que la Bordetella pertussis, patógeno de la tor ferina, considerada inicialmente como una bacteria extracelular, es capaz de invadir a macrófagos alveolares y otras células. Esta invasión intracelular es mediada por la expresión del gen vir; esta bacteria también induce apoptosis. Por otro lado, las bacterias extracelulares liberan toxinas, que, dentro de la célula huésped, inducen apoptosis. Hay por lo menos tres mecanismos por medio de los cuales las exotoxinas ingresan a las células. La forma como producen apoptosis es desconocida, pero se ha especulado que la ADP ribosilación del factor 2 de elongación (EF-2) es requerida para la fragmentación del ADN, como es el caso de la toxina diftérica (TXD) y la toxina A de la Pseudomonas aeruginosa (PEA). Otras toxinas, como son la leucotoxina del Actinobacillus actinomycetemcomitans y la toxina Shiga de la Shigella dysenteriae, también producen fragmentación del ADN y cambios morfológicos de la Célula huésped. Recientemente se ha reportado que la toxina A de Clostridium difficile induce apoptosis en células cebadas de rata. Así mismo, lipopéptidos sintéticos bacterianos y superantígenos bacterianos son capaces de inducir apoptosis (este último in vivo). La inducción de apoptosis por microorganismos intracelulares puede ser un mecanismo importante de citotoxicidad y una vía efectiva para que éstos combatan eficazmente a las células del sistema inmune, lo que podría contribuir a la patogénesis de las enfermedades causadas por estos microorganismos.