Plant-Origin Components: New Players to Combat Antibiotic Resistance in Klebsiella pneumoniae.

Klebsiella pneumoniae (Kpn) is an opportunistic pathogen that causes intrahospital complications such as pneumonia, liver abscesses, soft tissue infections, urinary infections, bacteraemia, and, in some cases, death. Since this bacterium has a higher frequency than other Gram-negative pathogens, it has become an important pathogen to the health sector. The adaptative genome of Kpn likely facilitates increased survival of the pathogen in diverse situations. Therefore, several studies have been focused on developing new molecules, synergistic formulations, and biomaterials that make it possible to combat and control infections with and dispersion of this pathogen. Note that the uncontrolled antibiotic administration that occurred during the pandemic led to the emergence of new multidrug-resistant strains, and scientists were challenged to overcome them. This review aims to compile the latest information on Kpn that generates intrahospital infections, specifically their pathogenicity-associated factors. Furthermore, it explains the natural-product-based treatments (extracts and essential oils) developed for Kpn infection and dispersion control.

Immunized mice naturally process in silico-derived peptides from the nucleocapsid of SARS-CoV-2.

BACKGROUND: The nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is an excellent immunogen that promotes the production of high-titer antibodies. N protein-derived peptides identified using a bioinformatics approach can potentially be used to develop a new generation of vaccines or diagnostic methods for detecting SARS-CoV-2 and its variants. However, further studies must demonstrate their capacity to be naturally processed by the immune system. OBJECTIVE: We aimed to examine the in vivo processing and recognition of in silico-identified peptides using the serum of immunized animals with the complete protein. METHODS: Recombinant N (Nrec) protein was subcutaneously administered to six Balb/c mice. Enzyme-linked immunosorbent assay (ELISA), western blotting, dot blotting, and immunoprecipitation were performed to evaluate the recognition of the complete protein and in silico-derived peptides. RESULTS: The serum of immunized mice recognized ~ 62.5 ng/µL of Nrec with high specificity to linear and conformational epitopes. Dot blot analysis showed that peptides Npep2 and Npep3 were the most reactive. CONCLUSION: Our data confirm the high immunogenicity of the SARS-CoV-2 N protein and provide evidence on the antigenicity of two peptides located in the N-arm/RNA-binding domain (Npep2) and oligomerization domain/C-tail (Npep3), considered the biologically active site of the N protein.

A Potential Role for Neuroinflammation in ADHD.

Attention deficit hyperactivity disorder (ADHD) is a neurobehavioural disorder in children and adolescents. Although increases in oxidative stress and disturbances of neurotransmitter system such as the dopaminergic and abnormalities in several brain regions have been demonstrated, the pathophysiology of ADHD is not fully understood. Nevertheless, ADHD involves several factors that have been associated with an increase in neuroinflammation. This chapter presents an overview of factors that may increase neuroinflammation and play a potential role in the development and pathophysiology of ADHD. The altered immune response, polymorphisms in inflammatory-related genes, ADHD comorbidity with autoimmune and inflammatory disorders and prenatal exposure to inflammation are associated with alterations in offspring brain development and are a risk factor; genetic and environmental risk factors that may increase the risk for ADHD and medications can increase neuroinflammation. Evidence of an association between these factors has been an invaluable tool for research on inflammation in ADHD. Therefore, evidence studies have made it possible to generate alternative therapeutic interventions using natural products as anti-inflammatories that could have great potential against neuroinflammation in ADHD.

Technical Implications of the Chicken Embryo Chorioallantoic Membrane Assay to Elucidate Neuroblastoma Biology.

The chorioallantoic membrane (CAM) can be used as a valuable research tool to examine tumors. The CAM can be used to investigate processes such as migration, invasion, and angiogenesis and to assess novel antitumor drugs. The CAM can be used to establish tumors in a straightforward, rapid, and cost-effective manner via xenotransplantation of cells or tumor tissues with reproducible results; furthermore, the use of the CAM adheres to the three "R" principle, i.e., replace, reduce, and refine. To achieve successful tumor establishment and survival, several technical aspects should be taken into consideration. The complexity and heterogeneity of diseases including neuroblastoma and cancers in general and their impact on human health highlight the importance of preclinical models that help us describe tumor-specific biological processes. These models will not only help in understanding tumor biology, but also allow clinicians to explore therapeutic alternatives that will improve current treatment strategies. In this review, we summarize the technical characteristics as well as the main findings regarding the use of this model to study neuroblastoma for angiogenesis, metastasis, drug sensitivity, and drug resistance.

The Use of Natural Compounds as a Strategy to Counteract Oxidative Stress in Animal Models of Diabetes Mellitus.

Diabetes mellitus (DM) is a chronic metabolic disease characterised by insulin deficiency, resulting in hyperglycaemia, a characteristic symptom of type 2 diabetes mellitus (DM2). DM substantially affects numerous metabolic pathways, resulting in ß-cell dysfunction, insulin resistance, abnormal blood glucose levels, impaired lipid metabolism, inflammatory processes, and excessive oxidative stress. Oxidative stress can affect the body's normal physiological function and cause numerous cellular and molecular changes, such as mitochondrial dysfunction. Animal models are useful for exploring the cellular and molecular mechanisms of DM and improving novel therapeutics for their safe use in human beings. Due to their health benefits, there is significant interest in a wide range of natural compounds that can act as naturally occurring anti-diabetic compounds. Due to rodent models' relatively similar physiology to humans and ease of handling and housing, they are widely used as pre-clinical models for studying several metabolic disorders. In this review, we analyse the currently available rodent animal models of DM and their advantages and disadvantages and highlight the potential anti-oxidative effects of natural compounds and their mechanisms of action.

Neuroprotective Effects of Quercetin in Pediatric Neurological Diseases.

Oxidative stress is a crucial event underlying several pediatric neurological diseases, such as the central nervous system (CNS) tumors, autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). Neuroprotective therapy with natural compounds used as antioxidants has the potential to delay, ameliorate or prevent several pediatric neurological diseases. The present review provides an overview of the most recent research outcomes following quercetin treatment for CNS tumors, ASD and ADHD as well as describes the potential in vitro and in vivo ameliorative effect on oxidative stress of bioactive natural compounds, which seems like a promising future therapy for these diseases. The neuroprotective effects of quercetin against oxidative stress can also be applied in the management of several neurodegenerative disorders with effects such as anti-cancer, anti-inflammatory, anti-viral, anti-obesity and anti-microbial. Therefore, quercetin appears to be a suitable adjuvant for therapy against pediatric neurological diseases.

Validity and reliability of the Mexican resilience measurement scale in families of children with chronic conditions.

BACKGROUND: The resilience to face disease is a process of positive adaptation despite the loss of health. It involves developing vitality and skills to overcome the negative effects of adversity, risks, and vulnerability caused by disease. In Mexico, the Mexican Resilience Measurement Scale (RESI-M) has been validated with a general population and has a five-factor structure. However, this scale does not allow evaluation of resilience in specific subpopulations, such as caregivers. METHOD: This study investigated the psychometric properties of RESI-M in 446 family caregivers of children with chronic diseases. A confirmatory factor analysis (CFA) was performed, internal consistency values were calculated using Cronbach's alpha coefficient, and mean comparisons were determined using t-tests. RESULTS: The expected five-factor model showed an adequate fit with the data based on a maximum likelihood test. The internal consistency for each factor ranged from .76 to .93, and the global internal consistency was .95. No average difference in RESI-M and its factors was found between women and men. CONCLUSION: The RESI-M showed internal consistency and its model of five correlated factors was valid among family caregivers of children with chronic diseases.

Human Heart Morphogenesis: A New Vision Based on In Vivo Labeling and Cell Tracking.

Despite the extensive information available on the different genetic, epigenetic, and molecular features of cardiogenesis, the origin of congenital heart defects remains unknown. Most genetic and molecular studies have been conducted outside the context of the progressive anatomical and histological changes in the embryonic heart, which is one of the reasons for the limited knowledge of the origins of congenital heart diseases. We integrated the findings of descriptive studies on human embryos and experimental studies on chick, rat, and mouse embryos. This research is based on the new dynamic concept of heart development and the existence of two heart fields. The first field corresponds to the straight heart tube, into which splanchnic mesodermal cells from the second heart field are gradually recruited. The overall aim was to create a new vision for the analysis, diagnosis, and regionalized classification of congenital defects of the heart and great arteries. In addition to highlighting the importance of genetic factors in the development of congenital heart disease, this study provides new insights into the composition of the straight heart tube, the processes of twisting and folding, and the fate of the conus in the development of the right ventricle and its outflow tract. The new vision, based on in vivo labeling and cell tracking and enhanced by models such as gastruloids and organoids, has contributed to a better understanding of important errors in cardiac morphogenesis, which may lead to several congenital heart diseases.

Embryonic Hyperglycemia Disrupts Myocardial Growth, Morphological Development, and Cellular Organization: An In Vivo Experimental Study.

Hyperglycemia during gestation can disrupt fetal heart development and increase postnatal cardiovascular disease risk. It is therefore imperative to identify early biomarkers of hyperglycemia during gestation-induced fetal heart damage and elucidate the underlying molecular pathomechanisms. Clinical investigations of diabetic adults with heart dysfunction and transgenic mouse studies have revealed that overexpression or increased expression of TNNI3K, a heart-specific kinase that binds troponin cardiac I, may contribute to abnormal cardiac remodeling, ventricular hypertrophy, and heart failure. Optimal heart function also depends on the precise organization of contractile and excitable tissues conferred by intercellular occlusive, adherent, and communicating junctions. The current study evaluated changes in embryonic heart development and the expression levels of sarcomeric proteins (troponin I, desmin, and TNNI3K), junctional proteins, glucose transporter-1, and Ki-67 under fetal hyperglycemia. Stage 22HH Gallus domesticus embryos were randomly divided into two groups: a hyperglycemia (HG) group, in which individual embryos were injected with 30 mmol/L glucose solution every 24 h for 10 days, and a no-treatment (NT) control group, in which individual embryos were injected with physiological saline every 24 h for 10 days (stage 36HH). Embryonic blood glucose, height, and weight, as well as heart size, were measured periodically during treatment, followed by histopathological analysis and estimation of sarcomeric and junctional protein expression by western blotting and immunostaining. Hyperglycemic embryos demonstrated delayed heart maturation, with histopathological analysis revealing reduced left and right ventricular wall thickness (-39% and -35% vs. NT). Immunoexpression levels of TNNI3K and troponin 1 increased (by 37% and 39%, respectively), and desmin immunofluorescence reduced (by 23%). Embryo-fetal hyperglycemia may trigger an increase in the expression levels of TNNI3K and troponin I, as well as dysfunction of occlusive and adherent junctions, ultimately inducing abnormal cardiac remodeling.

In vivo biocompatibility testing of nanoparticle-functionalized alginate-chitosan scaffolds for tissue engineering applications.

Background: There is a strong interest in designing new scaffolds for their potential application in tissue engineering and regenerative medicine. The incorporation of functionalization molecules can lead to the enhancement of scaffold properties, resulting in variations in scaffold compatibility. Therefore, the efficacy of the therapy could be compromised by the foreign body reaction triggered after implantation. Methods: In this study, the biocompatibilities of three scaffolds made from an alginate-chitosan combination and functionalized with gold nanoparticles (AuNp) and alginate-coated gold nanoparticles (AuNp + Alg) were evaluated in a subcutaneous implantation model in Wistar rats. Scaffolds and surrounding tissue were collected at 4-, 7- and 25-day postimplantation and processed for histological analysis and quantification of the expression of genes involved in angiogenesis, macrophage profile, and proinflammatory (IL-1ß and TNFα) and anti-inflammatory (IL-4 and IL-10) cytokines. Results: Histological analysis showed a characteristic foreign body response that resolved 25 days postimplantation. The intensity of the reaction assessed through capsule thickness was similar among groups. Functionalizing the device with AuNp and AuNp + Alg decreased the expression of markers associated with cell death by apoptosis and polymorphonuclear leukocyte recruitment, suggesting increased compatibility with the host tissue. Similarly, the formation of many foreign body giant cells was prevented. Finally, an increased detection of alpha smooth muscle actin was observed, showing the angiogenic properties of the elaborated scaffolds. Conclusion: Our results show that the proposed scaffolds have improved biocompatibility and exhibit promising potential as biomaterials for elaborating tissue engineering constructs.

Behavior of immunoglobulin G antibodies for SARS-COV-2 in Mexican pediatric patients with comorbidities: a prospective comparative cohort study.

Background: More than two years after the pandemic of COVID-19 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) there is a great lack of information. The presence of immunoglobulin G (IgG) have been related with disease severity. Patients with comorbidities could develop more severe infection; however, the evaluation of the humoral response in pediatric population are needed especially in patients with comorbidities. Our aim was to describe the behavior of IgG in pediatric patients and to know if there is a difference between patients with comorbidities. Methods: A prospective comparative cohort study was carried out in a single center from June 2020 to January 2021, with a follow-up of 6 months. The study included all the subjects with confirmatory test for SARS-CoV-2 from 1 month to 17 years 11 months, the follow-up of the disease's evolution and measurement of IgG antibodies was collected. We obtained the clinical data, and comorbidities like arterial hypertension, diabetes, obesity, and cancer, the initial symptoms were recorded as well as the evolution regarding the severity of COVID-19 and the need for hospitalization, intensive care unit or mechanical ventilation. The follow up was carried out through medical consultation with an appointment every month that included direct interrogation, examination, and peripheral blood collection for the IgG quantification. The antibodies detection was done through peripheral blood and chemiluminescence microparticle immunoassay. Results: A total of 237 patients with positive polymerase chain reaction (PCR) for SARS-COV-2 were included, of which 147 presented IgG antibodies (62%), 112 (76%) without comorbidity and 35 (24%) with comorbidities, by the sixth month only 2.7% continue with positive antibody measurements. Patients with comorbidities reach higher IgG levels than patients without comorbidities the basal titters were: 5.17 for patients without comorbidities vs. 6.96 for the group with comorbidities (P<0.001). Conclusions: We found an association between the presence of comorbidities and high levels of IgG units in pediatric patients with COVID-19. Additionally, patients with more severe course of the disease have higher levels of IgG and by the third month less than 35% have immunity.

Frequency of respiratory virus-associated infection among children and adolescents from a tertiary-care hospital in Mexico City.

Acute respiratory infections (ARIs) are a major cause of morbidity and mortality among children. The causative pathogens show geographic and seasonal variations. We retrospectively evaluated the frequency and seasonality of respiratory pathogens in children and adolescents (age: 0-19 years) with ARIs treated between January 1, 2021, and March 31, 2022, at a single center in Mexico. Out of 2400 patients, 1,603 were diagnosed with SARS-CoV-2 infection and 797 were diagnosed with other common respiratory pathogens (CRPs). Of the 797 patients, 632 were infected with one CRP and 165 with > 2 CRPs. Deaths occurred only in SARS-CoV-2-infected patients. Rhinovirus/Enterovirus, respiratory syncytial virus B, and parainfluenza virus 3 were the most prevalent in cases with single and multiple infections. CRP showed a high frequency between autumn and winter of 2021, with higher incidence of hospitalization compared to COVID-19. The main comorbidities were immunosuppression, cardiovascular disease (CD), and asthma. The frequency of CRPs showed a downward trend throughout the first half of 2021. CRPs increased in single- and co-infection cases between the fourth and fifth waves of COVID-19, probably due to decreased nonpharmaceutical interventions and changes in diagnostic tests. Age, cyanosis (symptom), and immunosuppression (comorbidity) were found to differentiate between SARS-CoV-2 infection and CRP infection.

Clinical Characteristics of Coronavirus Disease (COVID-19) in Mexican Children and Adolescents.

BACKGROUND: We analyzed the demographic, clinical, and diagnostic data of children and adolescents in Mexico, from the first case of coronavirus disease (COVID-19) to 28 February 2022. METHODS: Using the open databases of the Ministry of Health and a tertiary pediatric hospital, we obtained demographic and clinical data from the beginning of the COVID-19 pandemic until 28 February 2022. In addition, quantitative reverse-transcription polymerase chain reaction outputs were used to determine the viral load, and structural protein-based serology was performed to evaluate IgG antibody levels. RESULTS: Of the total 437,832 children and adolescents with COVID-19, 1187 died. Of these patients, 1349 were admitted to the Hospital Infantil de Mexico Federico Gómez, and 11 died. Obesity, asthma, and immunosuppression were the main comorbidities, and fever, cough, and headache were the main symptoms. In this population, many patients have a low viral load and IgG antibody levels. CONCLUSION: During the first 2 years of the COVID-19 pandemic in Mexico, children and adolescents had low incidence and mortality. They are a heterogeneous population, but many patients had comorbidities such as obesity, asthma, and immunosuppression; symptoms such as fever, cough, and headache; and low viral load and IgG antibodies.

Clinical features and severe acute respiratory syndrome-coronavirus-2 structural protein-based serology of Mexican children and adolescents with coronavirus disease 2019.

Severe acute respiratory syndrome (SARS)-coronavirus (CoV)-2 infection in children and adolescents primarily causes mild or asymptomatic coronavirus disease 2019 (COVID-19), and severe illness is mainly associated with comorbidities. However, the worldwide prevalence of COVID-19 in this population is only 1%-2%. In Mexico, the prevalence of COVID-19 in children has increased to 10%. As serology-based studies are scarce, we analyzed the clinical features and serological response (SARS-CoV-2 structural proteins) of children and adolescents who visited the Hospital Infantil de México Federico Gómez (October 2020-March 2021). The majority were 9-year-old children without comorbidities who were treated as outpatients and had mild-to-moderate illness. Children aged 6-10 years and adolescents aged 11-15 years had the maximum number of symptoms, including those with obesity. Nevertheless, children with comorbidities such as immunosuppression, leukemia, and obesity exhibited the lowest antibody response, whereas those aged 1-5 years with heart disease had the highest levels of antibodies. The SARS-CoV-2 spike receptor-binding domain-localized peptides and M and E proteins had the best antibody response. In conclusion, Mexican children and adolescents with COVID-19 represent a heterogeneous population, and comorbidities play an important role in the antibody response against SARS-CoV-2 infection.

HP0953 - hypothetical virulence factor overexpresion and localization during Helicobacter pylori infection of gastric epithelium.

BACKGROUND: The high prevalence and persistence of Helicobacter pylori (H. pylori) infection, as well as the diversity of pathologies related to it, suggest that the virulence factors used by this microorganism are varied. Moreover, as its proteome contains 340 hypothetical proteins, it is important to investigate them to completely understand the mechanisms of its virulence and survival. We have previously reported that the hypothetical protein HP0953 is overexpressed during the first hours of adhesion to inert surfaces, under stress conditions, suggesting its role in the environmental survival of this bacterium and perhaps as a virulence factor. AIM: To investigate the expression and localization of HP0953 during adhesion to an inert surface and against gastric (AGS) cells. METHODS: Expression analysis was performed for HP0953 during H. pylori adhesion. HP0953 expression at 0, 3, 12, 24, and 48 h was evaluated and compared using the Kruskal-Wallis equality-of-populations rank test. Recombinant protein was produced and used to obtain polyclonal antibodies for immunolocalization. Immunogold technique was performed on bacterial sections during adherence to inert surfaces and AGS cells, which was analyzed by transmission electron microscopy. HP0953 protein sequence was analyzed to predict the presence of a signal peptide and transmembrane helices, both provided by the ExPASy platform, and using the GLYCOPP platform for glycosylation sites. Different programs, via, I-TASSER, RaptorX, and HHalign-Kbest, were used to perform three-dimensional modeling. RESULTS: HP0953 exhibited its maximum expression at 12 h of infection in gastric epithelium cells. Immunogold technique revealed HP0953 localization in the cytoplasm and accumulation in some peripheral areas of the bacterial body, with greater expression when it is close to AGS cells. Bioinformatics analysis revealed the presence of a signal peptide that interacts with the transmembrane region and then allows the release of the protein to the external environment. The programs also showed a similarity with the Tip-alpha protein of H. pylori. Tip-alpha is an exotoxin that penetrates cells and induces tumor necrosis factor alpha production, and HP0953 could have a similar function as posttranslational modification sites were found; modifications in turn require enzymes located in eukaryotic cells. Thus, to be functional, HP0953 may necessarily need to be translocated inside the cell where it can trigger different mechanisms producing cellular damage. CONCLUSION: The location of HP0953 around infected cells, the probable posttranslational modifications, and its similarity to an exotoxin suggest that this protein is a virulence factor.

Pseudotyped Vesicular Stomatitis Virus-Severe Acute Respiratory Syndrome-Coronavirus-2 Spike for the Study of Variants, Vaccines, and Therapeutics Against Coronavirus Disease 2019.

World Health Organization (WHO) has prioritized the infectious emerging diseases such as Coronavirus Disease (COVID-19) in terms of research and development of effective tests, vaccines, antivirals, and other treatments. Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2), the etiological causative agent of COVID-19, is a virus belonging to risk group 3 that requires Biosafety Level (BSL)-3 laboratories and the corresponding facilities for handling. An alternative to these BSL-3/-4 laboratories is to use a pseudotyped virus that can be handled in a BSL-2 laboratory for study purposes. Recombinant Vesicular Stomatitis Virus (VSV) can be generated with complementary DNA from complete negative-stranded genomic RNA, with deleted G glycoprotein and, instead, incorporation of other fusion protein, like SARS-CoV-2 Spike (S protein). Accordingly, it is called pseudotyped VSV-SARS-CoV-2 S. In this review, we have described the generation of pseudotyped VSV with a focus on the optimization and application of pseudotyped VSV-SARS-CoV-2 S. The application of this pseudovirus has been addressed by its use in neutralizing antibody assays in order to evaluate a new vaccine, emergent SARS-CoV-2 variants (delta and omicron), and approved vaccine efficacy against variants of concern as well as in viral fusion-focused treatment analysis that can be performed under BSL-2 conditions.

Unusual Inflammatory Tinea Infections: Majocchi's Granuloma and Deep/Systemic Dermatophytosis.

PURPOSE OF REVIEW: Inflammatory tinea is an uncommon group of dermatophyte entities that predominantly cause fungal infection of the skin and hair. This review intends to present all of the available evidence regarding its epidemiology, etiopathogenesis, clinical features, and diagnostic methods as well as treatments recommended for various inflammatory tinea infections. This article provides a review of Majocchi's granuloma and dermatophytic or Hadida's disease. RECENT FINDINGS: The new phylogenetic classification of dermatophytes includes nine genera, and those that affect humans are Trichophyton, Microsporum, Epidermophyton, and Nannizzia. Furthermore, molecular advancements have revealed impaired antifungal immune responses caused by inflammatory tinea, which are detailed in this article. SUMMARY: The common denominator in these pathologies is the presence of impaired immune responses and, consequently, an impaired inflammatory response by the host. It is necessary to be familiar with these immunological characteristics in order to use the appropriate diagnostic methods and to provide adequate treatment.

Antitumor Effects of Natural Compounds Derived from Allium sativum on Neuroblastoma: An Overview.

Garlic (Allium sativum) has been used in alternative medicine to treat several diseases, such as cardiovascular and neurodegenerative diseases, cancer, and hepatic diseases. Several publications have highlighted other features of garlic, including its antibacterial, antioxidative, antihypertensive, and antithrombotic properties. The properties of garlic result from the combination of natural compounds that act synergistically and cause different effects. Some garlic-derived compounds have been studied for the treatment of several types of cancer; however, reports on the effects of garlic on neuroblastoma are scarce. Neuroblastoma is a prevalent childhood tumor for which the search for therapeutic alternatives to improve treatment without affecting the patients' quality of life continues. Garlic-derived compounds hold potential for the treatment of this type of cancer. A review of articles published to date on some garlic compounds and their effect on neuroblastoma was undertaken to comprehend the possible therapeutic role of these compounds. This review aimed to analyze the impact of some garlic compounds on cells derived from neuroblastoma.

Analysis of the Behaviour of Immunoglobulin G Antibodies in Children and Adults Convalescing From Severe Acute Respiratory Syndrome-Coronavirus-2 Infection.

The pandemic caused by SARS CoV-2 (COVID-19) has affected millions of people since 2020. There are clinical differences and in mortality between the adult and paediatric population. Recently, the immune response through the development of antibodies has gained relevance due to the risk of reinfection and vaccines' development. Objective: Was to compare the association of clinical history and the clinical presentation of the disease with the development of IgG antibodies against SARS-CoV-2 in paediatric and adult patients with a history of positive reverse transcriptase-polymerase chain reaction (RT-PCR) results. Methods: Cross-sectional observational study carried out in a Paediatric Hospital in Mexico City included patients under 18 years of age and health personnel with positive RT-PCR for COVID-19 comparing antibody expression. The development of specific IgG antibodies was measured, the presence of comorbidities, duration, and severity of symptoms was determined. Results: Sixty-one subjects (20 < 18 years and 41 > 18 years) were analysed. The median sample collection was 3 weeks. There were no differences in the expression of specific antibodies; no differences were shown according to the symptoms' severity. A positive correlation (r = 0.77) was demonstrated between the duration of symptoms and antibody levels. Conclusions: In conclusion, there is a clear association between the duration of the symptoms associated with SARS-CoV-2 infection and the IgG units generated in paediatric and adult patients convalescing from COVID-19.