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Background: In Mexico, 75% of diabetes mellitus type 2 (DMT2) patients are not in glycaemic control criteria (HbA1c<7%); this entails a significantly variable drug response. Amongst the factors influencing such variability, are genetics, more specifically, single nucleotide polymorphisms (SNPs). Three genes implied in metformin pharmacokinetics are SLC22A1, SLC22A2, and SLC22A3, which are polymorphic. While there have been cross-sectional studies on their SNPs impact over drug response, a longitudinal study would contribute valuable information on their effect over time. Methods: SNPs of SLC22A1 (rs72552763, rs622342, rs12208357, rs2282143, rs594709, rs628031, and rs683369), SLC22A2 (rs316019), and SLC22A3 (rs2076828), were determined through PCR-TR. The clinical records of 69 patients undergoing metformin monotherapy were retrospectively assessed. Metformin is the first line treatment against DMT2. A level of HbA1c <7% (time 0) was considered as an inescapable inclusion criterion. The study's cases were those patients who reported HbA1c ≥ 7% (time1) after time 0 (t0). Kaplan-Meier curves including a Log-Rank test and a Cox multivariate analysis of proportional risks were performed. Aim: Determining clinical, biochemical, and genetic variables which may affect non-control (HbA1c ≥ 7%) survival time spans amongst DMT2 Mexican-Mestizo patients undergoing metformin monotherapy at Hospital Regional de Alta Especialidad de Ixtapaluca (HRAEI) between October 2013 and December 2023. Results: All 69 patients were monitored over a median period of 642 days (273-1,134). A comparison between time 0 and time 1 (t1) revealed differences in weight (p = 0.036), metformin dose mg/kg/day (p = 0.003), plasmatic glucose mg/dL (p = 0.048), and HbA1c (p < 0.001). The median non-control survival rate was different across the 3 genotypes of rs62552763 in SLC22A1 (p = 0.0034) and the dominant genotypic model GAT/GAT vs. GAT/del + del/del (p = 0.009). There were differences between rs622342 genotypes as well (p = 0.041). In GAT/GAT the Cox model found HR = 0.407 (IC95%: 0.202-0.818, p = 0.011) in the univariate analysis and HR = 0.418 (IC95%: 0.204-0.856, p = 0.034) in the multivariate analysis, adjusted by initial metformin dose (mg/kg/day), initial weight (kg), and final metformin dose (mg/kg/day). Genotype A/A of rs622342 in SLC22A1, reported HR = 0.392 (IC95%: 0.169-0.910, p = 0.029) in the multivariate analysis as well. Conclusion: Among DMT2 Mexican-Mestizo patients undergoing metformin monotherapy the minor allele del in rs72552763 and the minor allele C in rs622342 reported a significantly shorter survival median respect to the wild type variant. Patients carrying del in rs72552763 or C in rs622342, both in SLC22A1, will reach non-control in less time with respect to other patients. Therefore these genotypes may constitute a therapeutic response biomarker for this population.
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ABSTRACT Introduction. Data on the prevalence of fungal coinfections/superinfections in patients with COVID-19 are limited. Objective. To describe the prevalence of fungal coinfections/superinfections in patients with COVID-19, as well as risk factors and demographic, clinical, and microbiological characteristics. Material and methods. We included patients with a confirmed COVID-19 diagnosis and a confirmed fungal infection hospitalized in the ICU from March 2020 to December 2021. We collected data on age, sex, comorbidities, hospital length of stay (days), laboratory (ferritin) and microbiological results, treatment for COVID-19, antifungal therapy, and outcomes obtained from the clinical records. Results. Only 11 out of 740 patients met the inclusion criteria. The coinfection rate was 0.3% and the superinfection was 1.2%. The most affected population was male adults. The coinfections/superinfections diagnosed were candiduria and candidemia, caused by Candida albicans, C. tropicalis, C. glabrata, C. lusitaniae, and Kluyveromyces marxianus (C. kefyr). In addition, tracheobronchitis due to Aspergillus fumigatus was found. The most used antifungals were fluconazole and caspofungin. The lethality in patients with fungal coinfections was 50% and superinfections, 22%. The length of hospital stay was 11-65 days. Eight patients required mechanical ventilation and six received corticosteroids. The main comorbidity was diabetes mellitus (81.8%). Conclusions. The rate of fungal coinfections/superinfections in COVID-19 patients was low, but the lethality found urges for routine fungal screening in patients with severe COVID-19 to timely detect fungal infections that may further compromise the patient's life.
RESUMEN Introducción. Los datos sobre la prevalencia de coinfecciones o sobreinfecciones fúngicas en pacientes con COVID-19 son limitados. Objetivo. Describir la prevalencia de coinfecciones o sobreinfecciones fúngicas en pacientes con COVID-19, así como los factores de riesgo y las características demográficas, clínicas y microbiológicas. Material y métodos. Se incluyeron pacientes con diagnóstico confirmado de COVID-19, hospitalizados en la unidad de cuidados intensivos y con infección fúngica confirmada entre marzo del 2020 y diciembre del 2021. Del expediente clínico se obtuvieron datos sobre edad, sexo, comorbilidades, días de estancia hospitalaria, resultados de laboratorio (ferritina) y microbiológicos, tratamiento contra COVID-19, terapia antifúngica y desenlace. Resultados. Once de 740 pacientes cumplieron con los criterios de inclusión. La tasa de coinfección fue del 0,3 % y la de sobreinfección fue del 1,2 %. La población más afectada fue la de hombres adultos. Las coinfecciones o sobreinfecciones diagnosticadas fueron candiduria y candidemia, causadas por Candida albicans, C. tropicalis, C. glabrata, C. lusitaniae y Kluyveromyces marxianus (C. kefyr). Además, se encontró una traqueobronquitis por Aspergillus fumigatus. Los antifúngicos más administrados fueron fluconazol y caspofungina. La letalidad en pacientes con coinfecciones fue del 50 % y con sobreinfecciones fúngicas, del 22 %. El tiempo de estancia intrahospitalaria fue de 11 a 65 días. Ocho de los pacientes requirieron asistencia respiratoria mecánica y seis recibieron corticoides. La principal comorbilidad fue diabetes mellitus (81,8 %). Conclusiones. La tasa de coinfecciones o sobreinfecciones por hongos en pacientes con COVID-19 fue baja, pero la letalidad de estas requiere, con urgencia, la realización de pruebas de rutina para detectar hongos en pacientes con COVID-19 grave para diagnosticar oportunamente infecciones fúngicas que puedan comprometer aún más la vida del paciente.
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Introduction: Data on the prevalence of fungal coinfections/superinfections in patients with COVID-19 are limited. Objective: To describe the prevalence of fungal coinfections/superinfections in patients with COVID-19, as well as risk factors and demographic, clinical, and microbiological characteristics. Material and methods: We included patients with a confirmed COVID-19 diagnosis and a confirmed fungal infection hospitalized in the ICU from March 2020 to December 2021. We collected data on age, sex, comorbidities, hospital length of stay (days), laboratory (ferritin) and microbiological results, treatment for COVID-19, antifungal therapy, and outcomes obtained from the clinical records. Results: Only 11 out of 740 patients met the inclusion criteria. The coinfection rate was 0.3% and the superinfection was 1.2%. The most affected population was male adults. The coinfections/superinfections diagnosed were candiduria and candidemia, caused by Candida albicans, C. tropicalis, C. glabrata, C. lusitaniae, and Kluyveromyces marxianus (C. kefyr). In addition, tracheobronchitis due to Aspergillus fumigatus was found. The most used antifungals were fluconazole and caspofungin. The lethality in patients with fungal coinfections was 50% and superinfections, 22%. The length of hospital stay was 11-65 days. Eight patients required mechanical ventilation and six received corticosteroids. The main comorbidity was diabetes mellitus (81.8%). Conclusions: The rate of fungal coinfections/superinfections in COVID-19 patients was low, but the lethality found urges for routine fungal screening in patients with severe COVID-19 to timely detect fungal infections that may further compromise the patient's life.
Introducción: Los datos sobre la prevalencia de coinfecciones o sobreinfecciones fúngicas en pacientes con COVID-19 son limitados. Objetivo: Describir la prevalencia de coinfecciones o sobreinfecciones fúngicas en pacientes con COVID-19, así como los factores de riesgo y las características demográficas, clínicas y microbiológicas. Material y métodos: Se incluyeron pacientes con diagnóstico confirmado de COVID-19, hospitalizados en la unidad de cuidados intensivos y con infección fúngica confirmada entre marzo del 2020 y diciembre del 2021. Del expediente clínico se obtuvieron datos sobre edad, sexo, comorbilidades, días de estancia hospitalaria, resultados de laboratorio (ferritina) y microbiológicos, tratamiento contra COVID-19, terapia antifúngica y desenlace. Resultados: Once de 740 pacientes cumplieron con los criterios de inclusión. La tasa de coinfección fue del 0,3 % y la de sobreinfección fue del 1,2 %. La población más afectada fue la de hombres adultos. Las coinfecciones o sobreinfecciones diagnosticadas fueron candiduria y candidemia, causadas por Candida albicans, C. tropicalis, C. glabrata, C. lusitaniae y Kluyveromyces marxianus (C. kefyr). Además, se encontró una traqueobronquitis por Aspergillus fumigatus. Los antifúngicos más administrados fueron fluconazol y caspofungina. La letalidad en pacientes con coinfecciones fue del 50 % y con sobreinfecciones fúngicas, del 22 %. El tiempo de estancia intrahospitalaria fue de 11 a 65 días. Ocho de los pacientes requirieron asistencia respiratoria mecánica y seis recibieron corticoides. La principal comorbilidad fue diabetes mellitus (81,8 %). Conclusiones: La tasa de coinfecciones o sobreinfecciones por hongos en pacientes con COVID-19 fue baja, pero la letalidad de estas requiere, con urgencia, la realización de pruebas de rutina para detectar hongos en pacientes con COVID-19 grave para diagnosticar oportunamente infecciones fúngicas que puedan comprometer aún más la vida del paciente.
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COVID-19 , Coinfección , Sobreinfección , Centros de Atención Terciaria , Humanos , Masculino , Coinfección/epidemiología , México/epidemiología , COVID-19/epidemiología , COVID-19/complicaciones , Sobreinfección/epidemiología , Femenino , Persona de Mediana Edad , Adulto , Anciano , Antifúngicos/uso terapéutico , Micosis/epidemiología , Micosis/tratamiento farmacológico , Micosis/diagnóstico , Prevalencia , Factores de Riesgo , Comorbilidad , Tiempo de Internación/estadística & datos numéricos , SARS-CoV-2 , Estudios RetrospectivosRESUMEN
In the present study, we evaluated the influence of maternal and neonatal factors on the efficiency of the placental transfer of neutralizing antibodies against SARS-CoV-2. Vaccination during pregnancy provides fetal and neonatal protection through the passive transplacental transfer of maternal neutralizing antibodies. To date, little information is available regarding the factors that affect the transfer of antibodies against SARS-CoV-2. A retrospective, cross-sectional, observational, and analytical study was carried out. It was found that several biological factors could be altering transplacental passive immunity after vaccination against COVID-19. In our study population, type 2 diabetes mellitus and chronic hypertension tended to decrease efficiency, while data from women with pre-eclampsia showed better indices compared to those from women with healthy pregnancies. Neonates born prematurely showed lower transfer rates when compared to healthy neonates. The premature rupture of membranes significantly decreased antibody transfer. Taken together, the data suggest that vaccination against COVID-19 during pregnancy is effective even under certain unfavorable clinical conditions for the mother, fetus, and neonate. It is important to create and disseminate immunization strategies in vulnerable populations to reduce maternal and perinatal morbidity and mortality associated with infections preventable by vaccination.
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The protection of the neonate against pathogens depends largely on the antibodies transferred placentally from the mother; for this reason, maternal vaccination against emerging viruses, such as SARS-CoV-2, is of vital importance. Knowing some of the immunogenic factors that could alter the placental transfer of antibodies could aid in understanding the immune response and neonatal protection after maternal vaccination. In this study, we analyzed the efficiency of the placental transfer of binding and neutralizing antibodies, as well as some factors that could alter the passive immune response, such as the trimester of gestation at the time of immunization, the number of doses received by the mother and the type of vaccine. Binding IgG antibodies were detected by ELISA, and the detection of neutralizing antibodies was carried out using flow cytometry. Our results show efficient transfer rates (>1), which are higher when maternal vaccination occurs during the third trimester of gestation. Antibodies are detectable in mothers and their neonates after 12 months of maternal immunization, suggesting than the vaccination against COVID-19 before and during pregnancy in the Mexican population induces a lasting neutralizing response in mothers and their newborns.
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Anticuerpos Neutralizantes , COVID-19 , Recién Nacido , Embarazo , Femenino , Humanos , Vacunas contra la COVID-19 , SARS-CoV-2 , COVID-19/prevención & control , Placenta , Vacunación , Madres , Anticuerpos AntiviralesRESUMEN
Coccidioidomycosis, caused by Coccidioides immitis and C. posadasii, causes significant morbidity and mortality, both in immunocompetent and immunocompromised people, mainly in endemic areas. The present work analyzed its epidemiology, diagnostic methods, and treatment by reviewing clinical cases published from 1950 to 2021. Fifty-nine articles were included, corresponding to 275 clinical cases. The results showed a higher incidence of coccidioidomycosis in the male gender than the female gender. The most affected age group was 31-40 years, and the most reported clinical presentation was disseminated with greater involvement in cutaneous and subcutaneous tissue, followed by the CNS, bone system, and peritoneum. The species most frequently reported was C. immitis. The most used treatment was azoles, followed by their combination with amphotericin B, monotherapy with amphotericin B, and alternative medicine. This work shows that epidemiological data outside the USA are still scarce. Serological tests are the preferred diagnostic method in daily medical practice, and cultures remain the gold standard. The treatment for coccidioidomycosis is ketoconazole and amphotericin B, individually or in combination.
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Brachybacterium conglomeratum, traditionally considered an environmental bacterium, has recently garnered attention for its potential involvement in human health. While prior research hinted at its pathogenic role in humans, our study aims to determine its prevalence and associations in diverse clinical contexts. We examined vaginal swabs from three distinct patient groups: patients with low-grade squamous intraepithelial lesions (LSIL), patients with cervicovaginal infections, and patients with a history of precancerous lesions undergoing follow-up. B. conglomeratum was present in all three patient groups, with the highest prevalence observed in the LSIL group. Statistically significant associations were primarily identified in the LSIL group, where B. conglomeratum was present in 60% of cases. Notably, the LSIL group exhibited coinfections with multiple high-risk oncogenotypes of human papillomavirus (HPV), suggesting potential synergistic effects, and understanding these microbial relationships and their influence on viral persistence, particularly with HPV, holds promise for mitigating HPV-related carcinogenesis. Furthermore, Gardnerella vaginalis and Atopobium vaginae were frequently detected in this group, along with Ureaplasma parvum as the predominant sexually transmitted bacterium. In all cases, B. conglomeratum was found in association with these microorganisms rather than as a sole pathogen. This coexistence underscores the intricate microbial interactions within cervicovaginal infections and precancerous lesions. This study marks the first report of B. conglomeratum prevalence in women with these clinical conditions.
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HIV-associated hemophagocytic lymphohistiocytosis (HLH) is mainly due to infections caused by viruses, fungi, and, to a lesser extent, bacteria, often with fatal results. Case presentation: A 15-year-old pediatric patient from another institution was admitted to our hospital with a fever of unknown origin (FUO). Clinical analysis and laboratory studies diagnosed HIV infection. The approach to an FUO in a patient with AIDS is much more complex due to the search for common etiologies and opportunistic infections. In this case, disseminated histoplasmosis, pulmonary tuberculosis, pneumocystosis, and ehrlichiosis were diagnosed, prompting an urgent and comprehensive approach to prevent mortality. Due to the multiple infections, HLH was triggered. An early intervention with trimethoprim (TMP)-sulfamethoxazole (SMX), liposomal amphotericin B, doxycycline, and quadruple antiphimic therapy to suppress infections, in conjunction with the early administration of HLH treatment, favored the survival of this patient.
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Dermatophytes are fungi included in the genera Trichophyton, Microsporum, Epidermophyton, Nannizzia, Paraphyton, Lophophyton, and Arthroderma. Molecular techniques have contributed to faster and more precise identification, allowing significant advances in phylogenetic studies. This work aimed to identify clinical isolates of dermatophytes through phenotypic (macro- and micromorphology and conidia size) and genotypic methods (sequences of ITS regions, genes of ß tubulin (BT2), and elongation factor α (Tef-1α)) and determine the phylogenetic relationships between isolates. Ninety-four dermatophyte isolates from Costa Rica, Guatemala, Honduras, Mexico, and the Dominican Republic were studied. The isolates presented macro- and micromorphology and conidia size described for the genera Trichophyton, Microsporum, and Epidermophyton. Genotypic analysis classified the isolates into the genera Trichophyton (63.8%), Nannizzia (25.5%), Arthroderma (9.6%), and Epidermophyton (1.1%). The most frequent species were T. rubrum (26 isolates, 27.6%), T. interdigitale (26 isolates, 27.6%), and N. incurvata (11 isolates, 11.7%), N. gypsea and A. otae (nine isolates, 9.6%), among others. The genotypic methods clarified the taxonomic status of closely related species. For instance, the ITS and BT2 markers of T. rubrum/T. violaceum did not differ but the Tef-1α gene did. On the other hand, the three markers differed in T. equinum/T. tonsurans. Therefore, the ITS, BT2, and Tef-1α genes are useful for typing in phylogenetic analyses of dermatophytes, with Tef-1α being the most informative locus. It should be noted that isolate MM-474 was identified as T. tonsurans when using ITS and Tef-1α, but when using BT2, it was identified as T. rubrum. On the other hand, no significant difference was found when comparing the methods for constructing phylogenies, as the topologies were similar.
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COVID-19-associated pulmonary aspergillosis (CAPA) has had a high incidence. In addition, it has been associated with prolonged hospital stays, as well as several predisposing risk factors, such as fungal factors (nosocomial organism, the size of the conidia, and the ability of the Aspergillus spp. of colonizing the respiratory tract), environmental factors (remodeling in hospitals, use of air conditioning and negative pressure in intensive care units), comorbidities, and immunosuppressive therapies. In addition to these factors, SARS-CoV-2 per se is associated with significant dysfunction of the patient's immune system, involving both innate and acquired immunity, with reduced CD4+ and CD8+ T cell counts and cytokine storm. Therefore, this review aims to identify the factors influencing the fungus so that coinfection with SARS-CoV-2 can occur. In addition, we analyze the predisposing factors in the fungus, host, and the immune response alteration due to the pathogenicity of SARS-CoV-2 that causes the development of CAPA.
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The COVID-19 pandemic has been a main concern over the last two years and has become one of the most important crises in the history of human health. Today, there is still a need for affordable and reliable diagnostic tests for massive disease monitoring. Previously, a set of highly specific DNA-aptamers (C7/C9) binding to the SARS-CoV-2 Spike (S) protein were isolated but its performance in clinical samples remained to be tested. Here, 242 samples were collected through three different methods and subjected to florescence-linked aptamer assays (FLAA) based on C7/C9 aptamers through two readout protocols. Then, a step-by-step statistical approach which included agreement tests, proportion comparisons and binomial and multinomial logistic regressions was used to predict optimal conditions for the novel C7/C9 FLAA test. RTqPCR threshold cycles, symptoms onset and processing time were influential factors on FLAA test results. Naturally occurring mutations on S were also detected and analyzed. Aminoacidic substitutions D614G and T732A appeared relevant for aptamer recognition although further studies are necessary. The methodology presented here is the first step to determine the performance and diagnosis across a range of clinical contexts and it might serve as a base for a complete analysis applicable to other designs of new diagnostic tests.
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Gestational diabetes (GD), pre-gestational diabetes (PD), and pre-eclampsia (PE) are morbidities affecting gestational health which have been associated with dysbiosis of the mother's gut microbiota. This study aimed to assess the extent of change in the gut microbiota diversity, short-chain fatty acids (SCFA) production, and fecal metabolites profile in a sample of Mexican women affected by these disorders. Fecal samples were collected from women with GD, PD, or PE in the third trimester of pregnancy, along with clinical and biochemical data. Gut microbiota was characterized by high-throughput DNA sequencing of V3-16S rRNA gene libraries; SCFA and metabolites were measured by High-Pressure Liquid Chromatography (HPLC) and (Fourier Transform Ion Cyclotron Mass Spectrometry (FT-ICR MS), respectively, in extracts prepared from feces. Although the results for fecal microbiota did not show statistically significant differences in alfa diversity for GD, PD, and PE concerning controls, there was a difference in beta diversity for GD versus CO, and a high abundance of Proteobacteria, followed by Firmicutes and Bacteroidota among gestational health conditions. DESeq2 analysis revealed bacterial genera associated with each health condition; the Spearman's correlation analyses showed selected anthropometric, biochemical, dietary, and SCFA metadata associated with specific bacterial abundances, and although the HPLC did not show relevant differences in SCFA content among the studied groups, FT-ICR MS disclosed the presence of interesting metabolites of complex phenolic, valeric, arachidic, and caprylic acid nature. The major conclusion of our work is that GD, PD, and PE are associated with fecal bacterial microbiota profiles, with distinct predictive metagenomes.
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Diabetes Gestacional , Microbioma Gastrointestinal , Preeclampsia , Embarazo , Humanos , Femenino , Microbioma Gastrointestinal/genética , ARN Ribosómico 16S/análisis , Disbiosis/microbiología , Heces/microbiología , Ácidos Grasos Volátiles/metabolismo , BacteriasRESUMEN
The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been one of the most catastrophic diseases observed in recent years. It has reported nearly 550 million cases worldwide, with more than 6.35 million deaths. In Mexico, an increased incidence and mortality of this disease were observed, where the immune response has been involved in the magnitude and severity. A critical version of the disease is accompanied by hyperinflammatory responses, with cytokine and defective cellular responses. A detailed understanding of the role of molecules and cells in the immune response during COVID-19 disease may help to generate effective protection mechanisms, improving those we already have. Here we analyzed blood samples obtained from patients at the Hospital Regional de Alta Especialidad de Ixtapaluca (HRAEI), Mexico, which were classified according to living guidance for clinical management of COVID-19 by the World Health Organization: asymptomatic, mild, severe, and critical disease. We observed increased interleukin (IL)-6 levels and a T-CD8+ and T-CD4+ cell reduction correlated with the critical disease version. Importantly, here, we described a significant reduction of CD11b+CD45highCD14low monocytes during severe disease, which displayed a non-classical profile, expressing IL-10, transforming growth factor (TGF)-ß, and indoleamine 2,3-dioxygenase (IDO)1 molecule. Moreover, CD11b+CD45highCD14low monocytes obtained from infected one-dose vaccinated patients (Pfizer® vaccine) who suffered minimal symptoms showed simultaneously a dual classical and no-classical profile expressing pro- and anti-inflammatory cytokines. These results suggest that blood monocytes expressing a dual pro- and anti-inflammatory profile might be a predictive marker for protection in the Mexican population during COVID-19 disease. KEY POINTS : ⢠Exacerbated immune response is associated with COVID-19 severe disease. ⢠Dual monocyte activation profile is crucial for predicting protection during COVID-19. ⢠Vaccination is crucial to induce the dual activation profile in monocytes.
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COVID-19 , Humanos , SARS-CoV-2 , Pandemias/prevención & control , Monocitos/metabolismo , México , Citocinas/metabolismoRESUMEN
As a result of the COVID-19 pandemic, various joint efforts have been made to support the creation of vaccines. Different projects have been under development, of which some are in the clinical evaluation stage and others in are in phase III with positive results. The aim of this paper was to describe the current situation of the development and production of vaccines available to the population to facilitate future research and continue developing and proposing ideas for the benefit of the population. So, we carried out a systematic review using databases such as PubMed, ScienceDirect, SciELO, and MEDLINE, including keywords such as "vaccines," "COVID-19," and "SARS-CoV-2". We reviewed the development and production of the anti-COVID vaccine and its different platforms, the background leading to the massive development of these substances, and the most basic immune aspects for a better understanding of their physiological activity and the immune response in those who receive the vaccine. We also analyzed immunization effects in populations with any medical or physiological conditions (such as immunosuppression, people with comorbidities, and pregnancy), as well as the response to immunization with heterologous vaccines and the hybrid immunity (the combination of natural immunity to SARS-CoV-2 with immunity generated by the vaccine). Likewise, we address the current situation in Mexico and its role in managing the vaccination process against SARS-CoV-2 at the national and international levels. There are still many clinical and molecular aspects to be described, such as the duration of active immunity and the development of immunological memory, to mention some of the most important ones. However, due to the short time since the global vaccination roll-out and that it has been progressive (not counting children and people with medical conditions), it is premature to say whether a second vaccination schedule will be necessary for the near future. Thus, it is essential to continue with health measures.
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Systemic candidiasis is a frequent opportunistic mycosis that can be life-threatening. Its main etiological agent is Candida albicans; however, the isolation of non-albicans Candida species has been increasing. Some of these species exhibit greater resistance to antifungals, so the rapid and specific identification of yeasts is crucial for a timely diagnosis and optimal treatment of patients. Multiple molecular assays have been developed, based mainly on polymerase chain reaction (PCR), showing high specificity and sensitivity to detect and identify Candida spp. Nevertheless, its application in diagnosis has been limited due to specialized infrastructure or methodological complexity. The objective of this study was to develop a PCR assay that detects and identifies some of the most common pathogenic Candida species and evaluate their diagnostic utility in blood samples and bronchial lavage. A pair of oligonucleotides was designed, CandF and CandR, based on sequence analysis of the 18S-ITS1-5.8S-ITS2-28S region of the rDNA of Candida spp., deposited in GenBank. The designed oligonucleotides identified C. albicans, C. glabrata, C. tropicalis, C. parapsilosis, C. krusei/Pichia kudriazevii, C. guilliermondii/Meyerozyma guilliermondii, C. lusitaniae/Clavispora lusitaniae, and C. dubliniensis using simplex PCR based on the amplicon size, showing a detection limit of 10 pg/µL of DNA or 103 yeasts/mL. Based on cultures as the gold standard, it was determined that the sensitivity (73.9%), specificity (96.3%), and the positive (94.4%) and negative (81.2%) predictive values of the PCR assay with the designed oligonucleotides justify their reliable use in diagnosis.
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The physiopathologic characteristics of COVID-19 (high levels of inflammatory cytokines and T-cell reduction) promote fungal colonization and infection, which can go unnoticed because the symptoms in both diseases are very similar. The objective of this work was to study the current epidemiology of systemic mycosis in COVID-19 times. A literature search on the subject (January 2020-February 2021) was performed in PubMed, Embase, Cochrane Library, and LILACS without language restrictions. Demographic data, etiological agent, risk factors, diagnostic methods, antifungal treatment, and fatality rate were considered. Eighty nine publications were found on co-infection by COVID-19 and pneumocystosis, candidiasis, aspergillosis, mucormycosis, coccidioidomycosis, or histoplasmosis. In general, the co-infections occurred in males over the age of 40 with immunosuppression caused by various conditions. Several species were identified in candidiasis and aspergillosis co-infections. For diagnosis, diverse methods were used, from microbiological to molecular. Most patients received antifungals; however, the fatality rates were 11-100%. The latter may result because the clinical picture is usually attributed exclusively to SARS-CoV-2, preventing a clinical suspicion for mycosis. Diagnostic tests also have limitations beginning with sampling. Therefore, in the remainder of the pandemic, these diagnostic limitations must be overcome to achieve a better patient prognosis.
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BACKGROUND: The molecular reclassification of the order Trichosporonales placed the medically relevant Trichosporon species into three genera of the family Trichosporonaceae: Cutaneotrichosporon, Trichosporon, and Apiotrichum. From the clinical and epidemiological standpoint, it is important to identify any species of the family Trichosporonaceae because they present different antifungal susceptibility profiles. In Mexico, little is known about trichosporonosis etiology because the fungi are identified through phenotypic methods. AIMS: To identify at a molecular level 12 yeast isolates morfologically compatible with Trichosporon, obtained from patients with superficial infections. METHODS: The yeast isolates were obtained from patients with white piedra, onychomycosis, and hand and foot dermatomycosis, and were identified morphologically and genotypically (sequencing of the IGS1 region and phylogenetic analysis using the Maximum Likelihood Method). The phylogenetic analysis included 40 yeast sequences from the order Trichosporonales and one from Cryptococcus neoformans as outgroup. RESULTS: Based on the molecular analysis, we identified three (25%) Trichosporon inkin isolates, two (16.7%) Trichosporon asteroides, two (16.7%) Cutaneotrichosporon mucoides, and one each (8.3%) of Trichosporon aquatile, Trichosporon asahii, Apiotrichum montevideense, Cutaneotrichosporon cutaneum, and Cutaneotrichosporon jirovecii. CONCLUSIONS: The molecular characterization of the isolates showed a broad diversity of species within the order Trichosporonales, particularly among onychomycosis. It is essential to identify these yeasts at the species level to delve into their epidemiology.
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Cryptococcus neoformans , Trichosporon , Basidiomycota , Humanos , Filogenia , Trichosporon/genéticaRESUMEN
Since Candida auris integrates strains resistant to multiple antifungals, research has been conducted focused on knowing which molecular mechanisms are involved. This review aims to summarize the results obtained in some of these studies. A search was carried out by consulting websites and online databases. The analysis indicates that most C. auris strains show higher resistance to fluconazole, followed by amphotericin B, and less resistance to 5-fluorocytosine and caspofungin. In C. auris, antifungal resistance to amphotericin B has been linked to an overexpression of several mutated ERG genes that lead to reduced ergosterol levels; fluconazole resistance is mostly explained by mutations identified in the ERG11 gene, as well as a higher number of copies of this gene and the overexpression of efflux pumps. For 5-fluorocytosine, it is hypothesized that the resistance is due to mutations in the FCY2, FCY1, and FUR1 genes. Resistance to caspofungin has been associated with a mutation in the FKS1 gene. Finally, resistance to each antifungal is closely related to the type of clade to which the strain belongs.
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The CSP (cell surface protein) microsatellite marker is useful for typing Aspergillus fumigatus isolates and determining relationships at the subpopulation level because it has shown high discriminatory power. In the present study, 90 A. fumigatus isolates from Mexico (MX), Argentina (AR), France (FR), and Peru (PE) were identified through a phylogenetic analysis using the benA gene fragment and were typed with the CSP microsatellite, and the types were identified using the nomenclature recommended in the literature. Genetic variability was analyzed through haplotype diversity, nucleotide diversity, polymorphic sites, and nucleotide differences between pairs of sequences. The population structure was evaluated using the Tajima's D statistic. No new CSP types were recorded in the MX, FR, and PE isolates, while in the AR isolates, two new CSP types were identified (t25 and t26). The most common CSP types in the studied populations were t01, t02, t03, and t04A; these results are consistent with findings in other countries. In addition, the genetic diversity parameters we obtained revealed that the greatest genetic diversity was found in the MX population, followed by AR and FR. No population structure was identified among the isolates studied.
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At present, there is no standardized marker that is routinely used in clinical laboratories to diagnose coccidioidomycosis. Thus, the goals of this study were to obtain a sequence characterized amplified region (SCAR) marker for the identification of Coccidioides spp., evaluate its specificity and sensitivity in fungal DNA-spiked blood and sputum samples, and compare it with previously described molecular markers. Specific amplified fragment length polymorphism (AFLP) amplicons for Coccidioides immitis and Coccidioides posadasii were cloned into the vector pGEM® -T Easy vector and sequenced to develop a SCAR marker. Oligonucleotides were designed to identify Coccidioides spp. by polymerase chain reaction (PCR), and the specificity and sensitivity of these oligonucleotides were tested with the DNA from related pathogens. The specificity and sensitivity of the SCAR marker was evaluated with blood and sputum samples spiked with Coccidioides DNA and compared with other previously described markers (621, GAC2, and Ag2/PRA). In addition, the conditions for its use were established using biological samples. A specific marker named SCAR300 was obtained to identify Coccidioides spp. that exhibited good sensitivity and specificity. The results showed that all of the markers tested in this study can identify Coccidioides spp. However, the SCAR300 and 621 markers were the most sensitive, whereas the SCAR300 marker was the most specific. Thus, the SCAR300 marker is a useful tool to identify Coccidioides spp.