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1.
Microbiol Res ; 285: 127739, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38763016

RESUMEN

Clostridioides difficile may have a negative impact on gut microbiota composition in terms of diversity and abundance, thereby triggering functional changes supported by the differential presence of genes involved in significant metabolic pathways, such as short-chain fatty acids (SCFA). This work has evaluated shotgun metagenomics data regarding 48 samples from four groups classified according to diarrhea acquisition site (community- and healthcare facility-onset) and positive or negative Clostridioides difficile infection (CDI) result. The metagenomic-assembled genomes (MAGs) obtained from each sample were taxonomically assigned for preliminary comparative analysis concerning differences in composition among groups. The predicted genes involved in metabolism, transport, and signaling remained constant in microbiota members; characteristic patterns were observed in MAGs and genes involved in SCFA butyrate and acetate metabolic pathways for each study group. A decrease in genera and species, as well as relative MAG abundance with the presence of the acetate metabolism-related gene, was evident in the HCFO/- group. Increased antibiotic resistance markers (ARM) were observed in MAGs along with the genes involved in acetate metabolism. The results highlight the need to explore the role of acetate in greater depth as a potential protector of the imbalances produced by CDI, as occurs in other inflammatory intestinal diseases.


Asunto(s)
Acetatos , Clostridioides difficile , Infecciones por Clostridium , Microbioma Gastrointestinal , Metagenoma , Metagenómica , Clostridioides difficile/genética , Acetatos/metabolismo , Humanos , Infecciones por Clostridium/microbiología , Ácidos Grasos Volátiles/metabolismo , Genoma Bacteriano , Butiratos/metabolismo , Redes y Vías Metabólicas/genética , Heces/microbiología , Diarrea/microbiología
2.
Int J Biol Macromol ; 259(Pt 1): 128944, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38145690

RESUMEN

Self-assembly involves a set of molecules spontaneously interacting in a highly coordinated and dynamic manner to form a specific supramolecular structure having new and clearly defined properties. Many examples of this occur in nature and many more came from research laboratories, with their number increasing every day via ongoing research concerning complex biomolecules and the possibility of harnessing it when developing new applications. As a phenomenon, self-assembly has been described on very different types of molecules (biomolecules including), so this review focuses on what is known about peptide self-assembly, its origins, the forces behind it, how the properties of the resulting material can be tuned in relation to experimental considerations, some biotechnological applications (in which the main protagonists are peptide sequences capable of self-assembly) and what is yet to be tuned regarding their research and development.


Asunto(s)
Biotecnología , Péptidos , Péptidos/química , Biotecnología/métodos , Desarrollo de Vacunas
3.
J Fungi (Basel) ; 9(12)2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-38132750

RESUMEN

Invasive fungal infections (IFIs) caused by Candida species are an emerging threat globally, given that patients at-risk and antifungal resistance are increasing. Antimicrobial peptides (AMPs) have shown good therapeutic capacity against different multidrug-resistant (MDR) microorganisms. This study evaluated the activity of the synthetic peptide, PNR20, against Candida albicans ATCC 10231 and a MDR Colombian clinical isolate of Candida auris. Perturbation of yeast cell surface was evaluated using scanning electron microscopy. Cell viability of Vero cells was determined to assess peptide toxicity. Additionally, survival, fungal burden, and histopathology of BALB/c mice infected intravenously with each Candida species and treated with PNR20 were analyzed. Morphological alterations were identified in both species, demonstrating the antifungal effect of PNR20. In vitro, Vero cells' viability was not affected by PNR20. All mice infected with either C. albicans or C. auris and treated with PNR20 survived and had a significant reduction in the fungal burden in the kidney compared to the control group. The histopathological analysis in mice infected and treated with PNR20 showed more preserved tissues, without the presence of yeast, compared to the control groups. This work shows that the utilization of PNR20 is a promising therapeutic alternative against disseminated candidiasis.

4.
Comp Immunol Microbiol Infect Dis ; 102: 102074, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37832162

RESUMEN

INTRODUCTION: Clostridium perfringens is a gram-positive, anaerobic sporulating bacillus which can infect several hosts, thereby being considered the causative agent of many gut illnesses. Some studies have suggested that C. perfringens's virulence factors may negatively affect gut microbiota homeostasis by decreasing beneficial bacteria; however, studies have failed to evaluate the simultaneous presence of other pathogenic bacteria, such as C. difficile (another sporulating bacillus known to play a role in gut microbiota imbalance). Conscious of the lack of compelling data, this work has ascertained how such microorganisms' coexistence can be associated with a variation in gut microbiota composition, compared to that of C. perfringens colonisation. METHODS: PCR was thus used for identifying C. perfringens and C. difficile in 98 samples. Amplicon-based sequencing of 16S- and 18S-rRNA genes' V4 hypervariable region from such samples was used for determining the microbiota's taxonomical composition and diversity. RESULTS: Small differences were observed in bacterial communities' taxonomic composition and diversity; such imbalance was mainly associated with groups having hospital-acquired diarrhoea. CONCLUSION: The alterations reported herein may have been influenced by C. difficile and diarrhoea acquisition site, despite C. perfringens' ability to cause alterations in microbiota due to its virulence factors. Our findings highlight the need for a holistic view of gut microbiota.


Asunto(s)
Clostridioides difficile , Infecciones por Clostridium , Microbioma Gastrointestinal , Animales , Clostridium perfringens/genética , Clostridioides difficile/genética , Clostridioides , Infecciones por Clostridium/microbiología , Infecciones por Clostridium/veterinaria , Bacterias , Diarrea/veterinaria , Factores de Virulencia/genética
5.
Mol Immunol ; 163: 86-103, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37769577

RESUMEN

Plasmodium vivax's biological complexity has restricted in vitro culture development for characterising antigens involved in erythrocyte invasion and their immunological relevance. The murine model is proposed as a suitable alternative in the search for therapeutic candidates since Plasmodium yoelii uses homologous proteins for its invasion. The AMA-1 protein is essential for parasite invasion of erythrocytes as it is considered an important target for infection control. This study has focused on functional PyAMA-1 peptides involved in host-pathogen interaction; the protein is located in regions under negative selection as determined by bioinformatics analysis. It was found that pyama1 has two highly conserved regions amongst species (>70%) under negative selection. Fourteen synthetic peptides spanning both conserved regions were evaluated; 5 PyAMA-1 peptides having high specific binding (HABP) to murine erythrocytes were identified. The parasite's invasion inhibition capability was analysed through in vitro assays, suggesting that peptides 42681 (43-ENTERSIKLINPWDKYMEKY-62), 42903 (206-RYSSNDANNENQPFSFTPEK-225) and 42904 (221-FTPEKIENYKDLSYLTKNLR-240) had greater than 50% inhibition profile and restricted P. yoelii intra-erythrocyte development. This work proposes that the screening of conserved HABPs under negative selective pressure might be good candidates for developing a synthetic anti-malarial vaccine since they share functionally-relevant characteristics, such as interspecies conservation, specific RBC binding profile, invasion and parasite development inhibition capability, and the predicted B-epitopes within were recognised by sera obtained from experimentally-infected mice.


Asunto(s)
Antimaláricos , Animales , Ratones , Antimaláricos/farmacología , Antimaláricos/metabolismo , Secuencia de Aminoácidos , Plasmodium falciparum , Proteínas Protozoarias , Péptidos , Eritrocitos/metabolismo , Antígenos de Protozoos
6.
Antibiotics (Basel) ; 12(8)2023 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-37627654

RESUMEN

Candidiasis is an opportunistic infection affecting immunosuppressed and hospitalized patients, with mortality rates approaching 40% in Colombia. The growing pharmacological resistance of Candida species and the emergence of multidrug-resistant Candida auris are major public health problems. Therefore, different antimicrobial peptides (AMPs) are being investigated as therapeutic alternatives to control candidiasis effectively and safely. This work aimed to evaluate the in vitro antifungal activity of three synthetic AMPs, PNR20, PNR20-1, and 35409, against ATCC reference strains of Candida albicans, Candida glabrata, Candida parapsilosis, Candida krusei, and Candida tropicalis, and clinical isolates of C. auris. Antifungal susceptibility testing, determined by broth microdilution, showed that the AMPs have antifungal activity against planktonic cells of all Candida species evaluated. In C. auris and C. albicans, the peptides had an effect on biofilm formation and cell viability, as determined by the XTT assay and flow cytometry, respectively. Also, morphological alterations in the membrane and at the intracellular level of these species were induced by the peptides, as observed by transmission electron microscopy. In vitro, the AMPs had no cytotoxicity against L929 murine fibroblasts. Our results showed that the evaluated AMPs are potential therapeutic alternatives against the most important Candida species in Colombia and the world.

7.
Hum Immunol ; 84(9): 484-491, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37380553

RESUMEN

NRAMP1 and VDR gene polymorphisms have been variably associated with susceptibility to tuberculosis (TB) amongst populations having different genetic background. NRAMP1 and VDR gene variants' association with susceptibility to active infection by Mycobacterium tuberculosis (Mtb) was analyzed in the Warao Amerindian population, an ethnic population from Venezuela's Orinoco delta region. Genomic DNA was extracted from individuals with and without TB to evaluate genetic polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Four NRAMP1 gene polymorphisms were analyzed: D543N (rs17235409), 3' UTR (rs17235416), INT4 (rs3731865), and 274C/T (rs2276631), and one VDR gene polymorphism: FokI (rs2228570). The results showed that the genotypes D543N-A/A, 3'UTR-TGTG+/+, INT4-C/C, and 274C/T-T/T of known polymorphism in the NRAMP1 gene, as well as the genotypes FokI-F/f and FokI-f/f in the VDR gene were most often found in indigenous Warao with active TB. Binomial logistic regression was used for evaluating associations between polymorphisms and risk of contracting TB, an association between NRAMP1-D543N-A/A genotype distribution and TB susceptibility was found in Warao Amerindians. Regarding Venezuelan populations having different genetic backgrounds; statistically significant TB associations concerning NRAMP1-D543N-A/A, INT4-C/C and 3'UTR-TGTG+/+ variant genotype distributions in Warao Amerindians (indigenous) compared to Creole (admixed non-indigenous population) individuals were found. In conclusion, the results thus indicated that the association between NRAMP1-D543N-A/A genotype and TB in Warao Amerindians could support such allele's role in host susceptibility to Mtb infection.


Asunto(s)
Proteínas de Transporte de Catión , Tuberculosis , Humanos , Regiones no Traducidas 3'/genética , Venezuela , Predisposición Genética a la Enfermedad , Proteínas de Transporte de Catión/genética , Tuberculosis/genética , Genotipo , Estudios de Casos y Controles
8.
World J Microbiol Biotechnol ; 39(8): 206, 2023 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-37221438

RESUMEN

Tuberculosis is a far-reaching, high-impact disease. It is among the top ten causes of death worldwide caused by a single infectious agent; 1.6 million tuberculosis-related deaths were reported in 2021 and it has been estimated that a third of the world's population are carriers of the tuberculosis bacillus but do not develop active disease. Several authors have attributed this to hosts' differential immune response in which cellular and humoral components are involved, along with cytokines and chemokines. Ascertaining the relationship between TB development's clinical manifestations and an immune response should increase understanding of tuberculosis pathophysiological and immunological mechanisms and correlating such material with protection against Mycobacterium tuberculosis. Tuberculosis continues to be a major public health problem globally. Mortality rates have not decreased significantly; rather, they are increasing. This review has thus been aimed at deepening knowledge regarding tuberculosis by examining published material related to an immune response against Mycobacterium tuberculosis, mycobacterial evasion mechanisms regarding such response and the relationship between pulmonary and extrapulmonary clinical manifestations induced by this bacterium which are related to inflammation associated with tuberculosis dissemination through different routes.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Humanos , Citocinas , Inflamación , Salud Pública
9.
Int J Med Microbiol ; 313(3): 151579, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37030083

RESUMEN

Plasmodium falciparum-related malaria represents a serious worldwide public health problem due to its high mortality rates. P. falciparum expresses rhoptry neck protein 4 (PfRON4) in merozoite and sporozoite rhoptries, it participates in tight junction-TJ formation via the AMA-1/RON complex and is refractory to complete genetic deletion. Despite this, which PfRON4 key regions interact with host cells remain unknown; such information would be useful for combating falciparum malaria. Thirty-two RON4 conserved region-derived peptides were chemically synthesised for determining and characterising PfRON4 regions having high host cell binding affinity (high activity binding peptides or HABPs). Receptor-ligand interaction/binding assays determined their specific binding capability, the nature of their receptors and their ability to inhibit in vitro parasite invasion. Peptides 42477, 42479, 42480, 42505 and 42513 had greater than 2% erythrocyte binding activity, whilst peptides 42477 and 42480 specifically bound to HepG2 membrane, both of them having micromolar and submicromolar range dissociation constants (Kd). Cell-peptide interaction was sensitive to treating erythrocytes with trypsin and/or chymotrypsin and HepG2 with heparinase I and chondroitinase ABC, suggesting protein-type (erythrocyte) and heparin and/or chondroitin sulphate proteoglycan receptors (HepG2) for PfRON4. Erythrocyte invasion inhibition assays confirmed HABPs' importance during merozoite invasion. PfRON4 800-819 (42477) and 860-879 (42480) regions specifically interacted with host cells, thereby supporting their inclusion in a subunit-based, multi-antigen, multistage anti-malarial vaccine.


Asunto(s)
Malaria , Plasmodium falciparum , Animales , Humanos , Plasmodium falciparum/genética , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo , Proteínas Portadoras/metabolismo , Péptidos , Eritrocitos/parasitología , Unión Proteica , Merozoítos/metabolismo , Hepatocitos/metabolismo , Antígenos de Protozoos
10.
Int J Mol Sci ; 24(6)2023 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-36982294

RESUMEN

Bovine babesiosis is caused by the Apicomplexa parasites from the genus Babesia. It is one of the most important tick-borne veterinary diseases worldwide; Babesia bovis being the species associated with the most severe clinical signs of the disease and causing the greatest economic losses. Many limitations related to chemoprophylaxis and the acaricides control of transmitting vectors have led to the adoption of live attenuated vaccine immunisation against B. bovis as an alternative control strategy. However, whilst this strategy has been effective, several drawbacks related to its production have prompted research into alternative methodologies for producing vaccines. Classical approaches for developing anti-B. bovis vaccines are thus discussed in this review and are compared to a recent functional approach to highlight the latter's advantages when designing an effective synthetic vaccine targeting this parasite.


Asunto(s)
Babesia bovis , Babesia , Enfermedades de los Bovinos , Enfermedades por Picaduras de Garrapatas , Animales , Bovinos , Vacunas Atenuadas , Vacunas Sintéticas
11.
Immunobiology ; 228(2): 152346, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36805110

RESUMEN

Mycobacterium tuberculosis is one of the most successful pathogens affecting humans, being the main cause of tuberculosis. It accounts for most infectious agent-related deaths worldwide; it has been estimated that a third of the world's population are bacillus carriers. This pathogen's evolutionary adaptation is mainly due to its ability to block a host's immune system by preventing it using an effective immune response in cases of active tuberculosis. Peptide-based synthetic vaccines represent an alternative for counteracting tuberculosis; however, although peptide antigens can be identified, they are not recognised by a host's immune system. An approach using dendritic cells as immunomodulating agents for increasing synthetic peptides' antigenic capacity has thus been advanced. Dendritic cells obtained from IL to 4- and GM-CSF-treated peripheral blood mononuclear cells were pulsed with synthetic Mtb protein peptides which have been reported as participating in mycobacteria-host interactions; their amino acid sequences were modified to improve MHC-II coupling and thus increase their recognition by a host's immune system. pMHC-II/TCR interaction triggered a lymphocyte response which controlled Mtb intracellular growth in infected macrophages. This work has been aimed at contributing to understanding dendritic cells' role in Mycobacterium tuberculosis protein peptide antigen presentation, thereby increasing individuals' immune response as a means of controlling the disease.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Humanos , Leucocitos Mononucleares , Péptidos/química , Macrófagos , Células Dendríticas
12.
Viruses ; 14(12)2022 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-36560678

RESUMEN

The cervical microbiota is essential in female sexual health, and its altered states seem to have a central role in the dynamic of high-risk papillomavirus (hrHPV) infections. This study aimed to evaluate the variation in bacterial communities' compositions according to hrHPV. We collected two samples per woman, with a difference of 12 ± 1 months between them, and performed a follow-up on 66 of these women. The viral load (VL) of the hrHPV was estimated by quantitative PCR (qPCR), then it was normalized (using the HMBS gene as reference) and transformed to the Log10 scale to facilitate the interpretation. The VL was categorized as Negative, without hrHPV copies; Low, less than 100 hrHPV copies; Medium, between 100 to 102 hrHPV copies; and High, >102 hrHPV copies. The microbiota composition was described through the Illumina Novaseq PE250 platform. The diversity analyses revealed changes regarding the hrHPV VL, where women with low VL (<100 hrHPV copies) presented high diversity. The community state type (CST) IV was the most common. However, in women with high VL, a lower association with Lactobacillus depletion was found. Lactobacillus gallinarum and L. iners were the most abundant species in women with high VL, whereas women with low VL had a 6.06 greater probability of exhibiting Lactobacillus dominance. We identified conspicuous differences in the abundance of 78 bacterial genera between women with low and high VL, where 26 were depleted (e.g., Gardnerella) and 52 increased (e.g., Mycoplasma). A multilevel mixed-effects linear regression showed changes in the diversity due to the interaction between the measurement time and the VL, with a decrease in diversity in the second follow-up in women with low VL (Coeff. = 0.47), whereas the women with medium VL displayed an increase in diversity (Coeff. = 0.58). Here, we report for the first time that the cervical microbiota is influenced by the number of copies of hrHPV, where a decrease in the abundance of Lactobacillus, greater diversity, and enrichment of bacterial taxa is relevant in women with low VL.


Asunto(s)
Microbiota , Infecciones por Papillomavirus , Neoplasias del Cuello Uterino , Femenino , Humanos , Virus del Papiloma Humano , Vagina , Cuello del Útero/microbiología , Microbiota/genética , Papillomaviridae/genética , Bacterias/genética
13.
Front Immunol ; 13: 926680, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36341338

RESUMEN

Major histocompatibility class II molecule-peptide-T-cell receptor (MHCII-p-TCR) complex-mediated antigen presentation for a minimal subunit-based, multi-epitope, multistage, chemically-synthesised antimalarial vaccine is essential for inducing an appropriate immune response. Deep understanding of this MHCII-p-TCR complex's stereo-electronic characteristics is fundamental for vaccine development. This review encapsulates the main principles for achieving such epitopes' perfect fit into MHC-II human (HLADRß̞1*) or Aotus (Aona DR) molecules. The enormous relevance of several amino acids' physico-chemical characteristics is analysed in-depth, as is data regarding a 26.5 ± 2.5Å distance between the farthest atoms fitting into HLA-DRß1* structures' Pockets 1 to 9, the role of polyproline II-like (PPIIL) structures having their O and N backbone atoms orientated for establishing H-bonds with specific HLA-DRß1*-peptide binding region (PBR) residues. The importance of residues having specific charge and orientation towards the TCR for inducing appropriate immune activation, amino acids' role and that of structures interfering with PPIIL formation and other principles are demonstrated which have to be taken into account when designing immune, protection-inducing peptide structures (IMPIPS) against diseases scourging humankind, malaria being one of them.


Asunto(s)
Vacunas contra la Malaria , Animales , Humanos , Péptidos , Aotidae/metabolismo , Receptores de Antígenos de Linfocitos T , Electrónica , Aminoácidos
14.
Heliyon ; 8(9): e10674, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36164515

RESUMEN

Insect cell lines represent a promising and expanding field as they have several research applications including biotechnology, virology, immunity, toxicology, cell signalling mechanisms and evolution. They constitute a powerful tool having a direct impact on human and veterinary medicine and agriculture. Although more than 1000 cell lines have currently been established from various insect species, Calliphora vicina-derived fly cell lines are lacking. This study was aimed at establishing a new C. vicina embryonic tissue-derived cell line. Adult flies were collected and embryonated eggs were mechanically homogenised and seeded in four types of culture media (L15, Grace's insect medium, Grace's/L15 and DMEM). Cell growth and morphological characteristics were recorded and cytogenetic and molecular patterns were determined. The CV-062020-PPB cell line was established and was shown to have optimal growth in Grace's/L15 medium. CV-062020-PPB cell monolayers that had been sub-cultured over 16 times consisted of firmly adhering cells having different morphologies; a fibroblast-like shape dominated and the karyotype had a 12-chromosome diploid number. RAPD-PCR analysis of the CV-062020-PPB cell line revealed a high similarity index and strong intraspecific relationship with C. vicina adult flies and a weaker relationship with the Lutzomyia longipalpis-derived cell line (Lulo). The CV-062020-PPB cell line constitutes the first cell line obtained from C. vicina embryonic tissues and represents an important basic and applied research tool.

15.
Microbiol Spectr ; 10(5): e0050222, 2022 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-36154277

RESUMEN

Clostridioides difficile infection (CDI) creates an imbalance in the intestinal microbiota due to the interaction of the components making up this ecosystem, but little is known about the impact of this disease on other microbial members. This work has thus been aimed at evaluating the taxonomic composition, potential gene-associated functions, virulence factors, and antimicrobial resistance profiles of gut microbiomes. A total of 48 DNA samples obtained from patients with health care facility-acquired (HCFO) and community-onset (CO) diarrhea were distributed in the following four groups according to CDI status: HCFO/+ (n = 13), HCFO/- (n = 8), CO/+ (n = 13), and CO/- (n = 14). These samples were subjected to shotgun metagenomics sequencing. Although the CDI groups' microbiota had microbiome alterations, the greatest imbalance was observed in the in the HCFO+/- groups, with an increase in common pathogens and phage populations, as well as a decrease in beneficial microorganisms that leads to a negative impact on some intestinal homeostasis-related metabolic processes. A reduction in the relative abundance of butyrate metabolism-associated genes was also detected in the HCFO groups (P < 0.01), with an increase in some virulence factors and antibiotic-resistance markers. A set of 51 differentially abundant species in the groups with potential association to CDI enabled its characterization, leading to their spatial separation by onset. Strong correlations between phages and some archaeal and bacterial phyla were identified. This highlighted the need to study the microbiota's various components since their imbalance is multifactorial, with some pathogens contributing to a greater or lesser extent because of their interaction with the ecosystem they inhabit. IMPORTANCE Clostridioides difficile infection represents a serious public health problem in different countries due to its high morbi-mortality and the high costs it represents for health care systems. Studies have shown the impact of this infection on intestinal microbiome homeostasis, mainly on bacterial populations. Our research provides evidence of the impact of CDI at both the compositional (bacteria, archaea, and viruses), and functional levels, allowing us to understand that the alterations of the microbiota occur systemically and are caused by multiple perturbations generated by different members of the microbiota as well as by some pathogens that take advantage of the imbalance to proliferate. Likewise, the 51 differentially abundant species in the study groups with potential association to CDI found in this study could help us envisage future treatments against this and other inflammatory diseases, improving future therapeutic options for patients.


Asunto(s)
Antiinfecciosos , Clostridioides difficile , Infecciones por Clostridium , Microbiota , Humanos , Clostridioides difficile/genética , Infecciones por Clostridium/microbiología , Bacterias , Antibacterianos , Homeostasis , Factores de Virulencia/genética , Butiratos
16.
Front Immunol ; 13: 859905, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35693819

RESUMEN

Fifty ~20-amino acid (aa)-long peptides were selected from functionally relevant SARS-CoV-2 S, M, and E proteins for trial B-21 and another 53 common ones, plus some new ones derived from the virus' main genetic variants for complementary trial C-21. Peptide selection was based on tremendous SARS-CoV-2 genetic variability for analysing them concerning vast human immunogenetic polymorphism for developing the first supramutational, Colombian SARS-protection (SM-COLSARSPROT), peptide mixture. Specific physicochemical rules were followed, i.e., aa predilection for polyproline type II left-handed (PPIIL) formation, replacing ß-branched, aromatic aa, short-chain backbone H-bond-forming residues, π-π interactions (n→π* and π-CH), aa interaction with π systems, and molecular fragments able to interact with them, disrupting PPIIL propensity formation. All these modified structures had PPIIL formation propensity to enable target peptide interaction with human leukocyte antigen-DRß1* (HLA-DRß1*) molecules to mediate antigen presentation and induce an appropriate immune response. Such modified peptides were designed for human use; however, they induced high antibody titres against S, M, and E parental mutant peptides and neutralising antibodies when suitably modified and chemically synthesised for immunising 61 major histocompatibility complex class II (MHCII) DNA genotyped Aotus monkeys (matched with their corresponding HLA-DRß1* molecules), predicted to cover 77.5% to 83.1% of the world's population. Such chemically synthesised peptide mixture represents an extremely pure, stable, reliable, and cheap vaccine for COVID-19 pandemic control, providing a new approach for a logical, rational, and soundly established methodology for other vaccine development.


Asunto(s)
COVID-19 , Vacunas contra la Malaria , Secuencia de Aminoácidos , Vacunas contra la COVID-19 , Antígenos de Histocompatibilidad Clase II/genética , Humanos , Imidazoles , Péptidos , SARS-CoV-2/genética , Sulfonamidas , Tiofenos
17.
Front Cell Infect Microbiol ; 12: 816574, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35433504

RESUMEN

Plasmodium falciparum is the most lethal human malaria parasite, partly due to its genetic variability and ability to use multiple invasion routes via its binding to host cell surface receptors. The parasite extensively modifies infected red blood cell architecture to promote its survival which leads to increased cell membrane rigidity, adhesiveness and permeability. Merozoites are initially released from infected hepatocytes and efficiently enter red blood cells in a well-orchestrated process that involves specific interactions between parasite ligands and erythrocyte receptors; symptoms of the disease occur during the life-cycle's blood stage due to capillary blockage and massive erythrocyte lysis. Several studies have focused on elucidating molecular merozoite/erythrocyte interactions and host cell modifications; however, further in-depth analysis is required for understanding the parasite's biology and thus provide the fundamental tools for developing prophylactic or therapeutic alternatives to mitigate or eliminate Plasmodium falciparum-related malaria. This review focuses on the cellular and molecular events during Plasmodium falciparum merozoite invasion of red blood cells and the alterations that occur in an erythrocyte once it has become infected.


Asunto(s)
Malaria Falciparum , Malaria , Animales , Eritrocitos/parasitología , Humanos , Malaria/metabolismo , Malaria Falciparum/metabolismo , Merozoítos , Plasmodium falciparum/genética , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo
18.
Front Genet ; 13: 772885, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35186024

RESUMEN

The major histocompatibility complex (MHC) exerts great influence on responses to infectious diseases and vaccination due to its fundamental role in the adaptive immune system. Knowledge about MHC polymorphism distribution among breeds can provide insights into cattle evolution and diversification as well as population-based immune response variability, thus guiding further studies. Colombian Simmental and Simbrah cattle's BoLA-DRB3 genetic diversity was compared to that of taurine and zebuine breeds worldwide to estimate functional diversity. High allele richness was observed for Simmental and Simbrah cattle; nevertheless, high homozygosity was associated with individual low sequence variability in both the ß1 domain and the peptide binding region (PBR), thereby implying reduced MHC-presented peptide repertoire size. There were strong signals of positive selection acting on BoLA-DRB3 in all populations, some of which were poorly structured and displayed common alleles accounting for their high genetic similarity. PBR sequence correlation analysis suggested that, except for a few populations exhibiting some divergence at PBR, global diversity regarding potential MHC-presented peptide repertoire could be similar for the cattle populations analyzed here, which points to the retention of functional diversity in spite of the selective pressures imposed by breeding.

19.
Prev Vet Med ; 200: 105591, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35149317

RESUMEN

Chlamydia psittaci is a highly zoonotic bacteria distributed worldwide; it is responsible for psittacosis, one of the most important infectious diseases affecting the Psittacidae, mostly parrots. This work was aimed at determining C. psittaci prevalence and genotype in 177 parrots confiscated in Colombia; cloacal swab (166) and faecal (177) samples were analysed from birds confiscated and housed in a Temporary Wildlife Reception Centre (Centro de Reception de Fauna Temporal). Conventional PCR was run on the samples for amplifying the MOMP gene and then the ompA gene. The C. psittaci genotype A was found in 81.3 % (144/177) of the birds analysed. Cloacal swabs accounted for 129/166 (77.7 %) positive samples and faecal matter for 53/177 (29.9 %), 38 birds proving positive for both types of sample; there was an 8.15 times greater probability of detection for cloacal swabs compared to faecal swabs (p < 0.05). Clinical examination findings were correlated with the animals' positivity for cloacal swabs, faecal matter or both, finding a statistically significant relationship with low respiratory rate (p < 0.05) and broken plumage for cloacal swab sample results (p < 0.1). Even though 85 % seroprevalence has previously been reported in Colombia using indirect ELISA, this study reports for the first time C. psittaci genotype A endemicity in psittacines in captivity in Colombia using molecular techniques, considering the zoonotic risk involved in having these birds as pets.


Asunto(s)
Enfermedades de las Aves , Chlamydophila psittaci , Loros , Psitacosis , Animales , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/microbiología , Chlamydophila psittaci/genética , Colombia/epidemiología , Prevalencia , Psitacosis/epidemiología , Psitacosis/veterinaria , Estudios Seroepidemiológicos
20.
PLoS One ; 17(1): e0262069, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35077465

RESUMEN

BACKGROUND: Cervical cancer (CC) promotion and prevention (P&P) programmes' challenge lies in guaranteeing that follow-up strategies have a real impact on reducing CC-related mortality rates. CC P&P programme compliance and coverage rates are relevant indicators for evaluating their success and good performance; however, such indicators' frequency rates are considerably lower among women living in rural and border areas. This study was aimed at identifying factors associated with CC screening programme attendance for women living in Colombia's Amazon region. METHODS: This study (qualitative and quantitative phases) was carried out between September 2015 and November 2016; women residing in the border towns of Leticia and Puerto Nariño participated in it. The first phase (qualitative) involved interviews and focus group discussions; this led to establishing factors related to CC P&P programme attendance which were used in the quantitative phase for designing a survey for determining the strength of association in a logistic regression model. The terms attendance and compliance were considered to apply to women who had followed the 1-1-3 scheme throughout their lives, i.e. a cytology examination every 3 years after receiving two consecutive negative annual cytology results. RESULTS: Inclusion criteria were met by 309 women (≥18-year-olds having an active sexual life, having resided in the target community for at least one year); 15.2% had suitable P&P programme follow-up. Screening programme attendance was positively associated with first intercourse after becoming 20 years-old (aOR: 3.87; 1.03-9.50 95%CI; p = 0.045), frequent contraceptive use (aOR: 3.11; 1.16-8.33 95%CI; p = 0.023), awareness of the age to participate in P&P programmes (aOR: 2.69; 1.08-6.68 95%CI; p = 0.032), awareness of cytology's usefulness in identifying cervical abnormalities (aOR: 2.43; 1.02-5.77 95%CI; p = 0.043) and considering cytology important (aOR: 2.64; 1.12-6.19 95%CI; p = 0.025). Women living in rural areas had a lower probability (aOR 0.43: 0.24-0.79 95%CI; p = 0.006) of adhering to CC P&P programmes. CONCLUSIONS: This study's findings suggested the need for including novel strategies in screening programmes which will promote CC P&P activities going beyond hospital outpatient attendance to reach the most remote or widely scattered communities, having the same guarantees regarding access, opportunity and quality. Including education-related activities and stimulating the population's awareness regarding knowledge about CC prevention could be one of the main tools for furthering the impact of attendance at and compliance with P&P programmes.


Asunto(s)
Neoplasias del Cuello Uterino , Femenino , Humanos
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