RESUMO

We evaluated the specificity of the primers OPF-01, P54, and 1253 to identify A. fumigatus, A. flavus, and A. niger, respectively, with the RAPD-PCR method. Eighty-two isolates belonging to the sections Fumigati, Flavi, and Nigri were used. The isolates were identified by phenotypic (macro- and micromorphology) and genotypic (partial sequences of the BenA gene) methods. The RAPD-PCR method was used to obtain polymorphic patterns with the primers OPF-01, P54, and 1253. The specificity of the polymorphic patterns of the isolates of each species was evaluated through the UPGMA clustering method and logistic regression model. All isolates of the genus Aspergillus were identified at the section level by macro- and micromorphology showing the typical morphology of the sections Fumigati, Flavi, and Nigri, and the species were identified by the construction of the phylogeny of the partial sequence of the BenA gene. The patterns' polymorphic strains obtained with the primers OPF-01, P54, and 1253 for the isolates of A. fumigatus, A. flavus, and A niger, respectively, showed the same polymorphic pattern as the reference strains for each species. To verify the specificity of the primers, they were tested with other species from the sections Fumigati, Flavi and Nigri. The results support that the primers OPF-01, P54, and 1253 generate polymorphic patterns by RAPD-PCR species specific to A. fumigatus, A. flavus, and A. niger, respectively.

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In this study, molecular typing using Randomly Amplified Polymorphic DNA (RAPD-PCR) was conducted on 16 original isolates of Metarhizium acridum obtained from locusts (Schistocerca piceifrons ssp. piceifrons.) in Mexico (MX). The analysis included reference strains of the genus Metarhizium sourced from various geographical regions. The isolates were identified by phenotypic (macro and micromorphology) and genotypic methods (RAPD-PCR and Amplified Fragment Length Polymorphisms (AFLP), through a multidimensional analysis of principal coordinates (PCoA) and a minimum spanning network (MST). Subsequently, Sequences-Characterized Amplified Region (SCAR) markers were developed for the molecular detection of M. acridum, these markers were chosen from polymorphic patterns obtained with 14 primers via RAPD-PCR. Phenotypic and genotypic characterization identified the MX isolates as M. acridum. Of all the polymorphic patterns obtained, only OPA04 and OPA05 were chosen, which presented species-specific bands for M. acridum, and further utilized to create SCAR markers through cloning and sequencing of the specific bands. The specificity of these two markers was confirmed via Southern hybridization. The SCAR markers (Ma-160OPA-05 and Ma-151OPA-04) exhibit remarkable sensitivity, detecting down to less than 0.1 ng, as well as high specificity, as evidenced by their inability to cross-amplify or generate amplification with DNAs from other strains of Metarhizium (as Metarhizium anisopliae) or different genera of entomopathogenic fungi (Cordyceps fumosorosea and Akanthomyces lecanii). These SCAR markers yield readily detectable results, showcasing high reproducibility. They serve as a valuable tool, especially in field applications.

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Microsporum canis is a widely distributed dermatophyte, which is among the main etiological agents of dermatophytosis in humans and domestic animals. This fungus invades, colonizes and nourishes itself on the keratinized tissues of the host through various virulence factors. This review will bring together the known information about the mechanisms, enzymes and their associated genes relevant to the pathogenesis processes of the fungus and will provide an overview of those virulence factors that should be better studied to establish effective methods of prevention and control of the disease. Public databases using the MeSH terms "Microsporum canis", "virulence factors" and each individual virulence factor were reviewed to enlist a series of articles, from where only original works in English and Spanish that included relevant information on the subject were selected. Out of the 147 articles obtained in the review, 46 were selected that reported virulence factors for M. canis in a period between 1988 and 2023. The rest of the articles were discarded because they did not contain information on the topic (67), some were written in different languages (3), and others were repeated in two or more databases (24) or were not original articles (7). The main virulence factors in M. canis are keratinases, fungilisins and subtilisins. However, less commonly reported are biofilms or dipeptidylpeptidases, among others, which have been little researched because they vary in expression or activity between strains and are not considered essential for the infection and survival of the fungus. Although it is known that they are truly involved in resistance, infection and metabolism, we recognize that their study could strengthen the knowledge of the pathogenesis of M. canis with the aim of achieving effective treatments, as well as the prevention and control of infection.

Assuntos

RESUMO

BACKGROUND: Infections are a major cause of morbidity and mortality in patients with pemphigus vulgaris (PV). One of the most common infections in these patients is candidiasis. This is probably due to the use of systemic immunosuppressants, including oral and intravenous corticosteroids, mainly in megadoses (pulse therapy), although it is unknown if there are other associated factors, in addition to immunosuppressive treatment. We determine the factors associated with candidiasis in PV patients in two second-care level hospitals in Mexico. METHODS: We reviewed 100 cases with PV. Cases were randomly selected from the databases of two second-care level hospitals between January 2010 and December 2019 (10 years). The primary endpoint was the incidence of candidiasis in patients with PV. RESULTS: One hundred patients with PV were enrolled in this retrospective study. Candidiasis was observed in 79 patients (79%). A maximum corticosteroid dose of 55 mg/day during the last year (p = 0.001) and a higher neutrophil/lymphocyte ratio were associated with candidiasis in patients with PV (p = 0.001). CONCLUSION: Risk factors favoring candidiasis in patients with PV are not only related to the use of corticosteroids, but also to demographic factors, the activity of the disease, and the systemic inflammation associated with autoimmunity.

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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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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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Malnutrition is a public health problem in developing countries, affecting the child population, which favors the appearance of infections such as oral candidiasis. In Mexico, information on the presence of oral colonization by Candida spp. in asymptomatic children is scarce. The present study aimed to determine the presence of Candida spp. in the oral cavity of asymptomatic preschool Mexican children and its association with their nutritional status. A sample of oral mucosa was obtained using a sterile swab and then inoculated in Sabouraud dextrose agar with antibiotics, and the yeast growth was phenotypically identified. The anthropometric profile of children was performed based on the guidelines of the International Society for the Advancement of Kinanthropometry. In addition, eating habits were investigated. The possible associations between the variables were determined through the chi-square test (IC95%, p < 0.05) (GraphPad Prism 8.0). Among the 743 assessed children (403 boys and 340 girls), the average age was 4.6 years, and the average nutritional status was normal (53.7%), followed by undernutrition (28.4%), overweight (12.4%) and obesity (5.5%). In 52 children, Candida was isolated, and the identified species were C. albicans (87.8%), C. glabrata (11.5%), C. krusei (5.8%) and C. parapsilosis (1.9%). The frequency of colonization was greater in males of six years (69.23%). There was no significant association between the colonization by Candida spp. and the nutritional status; however, a relation was observed with a high intake of simple carbohydrates.

RESUMO

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.