Search bioRxiv⌕ Search

Biology subjects

Ceapa, C. D.

Publications and source records attributed to Ceapa, C. D..

4 recordsLinked to original sources

Comparative genomics of clinical isolates of Pseudomonas aeruginosa from cystic fibrosis patients in Mexico

Pseudomonas aeruginosa (P. aeruginosa) is the primary pathogen responsible for morbidity and mortality in patients with cystic fibrosis (CF). Its genomic plasticity and constant selective pressure from antimicrobial treatments have favored the emergence of multidrug-resistant clones. This study conducted a comparative genomic analysis of 41 P. aeruginosa isolated from pediatric patients with CF in Mexico from 2015 to 2024, with the aim of characterizing their evolutionary dynamics, resistome, and virulome. Whole-genome sequencing (MGI, Illumina, and PacBio platforms) was used, with de novo assemblies performed using Unicycler v0.4.8 on the BV-BRC platform. The databases used for the resistome were CARD and NDARO, and for the virulome, VFDB. Phylogenetic reconstruction was based on core-genome alignments generated with Roary v3.13.0, with maximum likelihood reconstruction performed in IQ-TREE v2.1.2. The statistical significance of the segregation of resistance and virulence patterns was evaluated using PERMANOVA analysis. The results revealed a significant clonal prevalence of sequence types (ST) 307 and ST 167. Phylogenomic analysis grouped the isolates into three main clades; Clade 1 stood out for having the highest resistance gene load (mean of 75 genes/genome), establishing itself as the main reservoir of multidrug-resistant profiles. Genotype-phenotype concordance reached 65.5% overall, with high accuracy for aminoglycosides (87.8%) and fluoroquinolones (82.9%). Furthermore, virulome analysis identified 67 distinct patterns that were significantly segregated among the clades (PERMANOVA: R2=0.31, p=0.001). These findings demonstrate that the evolution of P. aeruginosa lineages in the pediatric clinical setting involves parallel and coordinated adaptations in both their resistance potential and their virulence arsenal. This study underscores the need to adopt a multidisciplinary approach to the clinical management of chronic P. aeruginosa infections in pediatric patients. The persistence of extensively drug-resistant (XDR) strains calls for the integration of genomic surveillance and functional diagnostics, as well as the search for therapeutic alternatives for the clinical management of patients with cystic fibrosis.

microbiology↗

Resistome, Virulome, Mobilome, And Biosynthetic Gene Clusters Adaptations of Acinetobacter Baumannii Mexican Strains Across the Pre- and of the COVID-19 Period: Insights from Whole-Genome Sequencing

BackgroundAcinetobacter baumannii is a critical multidrug-resistant pathogen whose genomic landscape in Mexico has been reshaped by the COVID-19 pandemic. While global studies have highlighted distinctive sequence type distributions, systematic analyses in Mexico remain limited. MethodsWe analyzed 194 genomes, including 47 newly sequenced post-COVID isolates (MIQ), alongside 147 publicly available genomes (HPG). Whole-genome sequencing was combined with phylogenetic reconstruction, resistome and virulome profiling based on gene presence and absence, mobilome analysis, and biosynthetic gene cluster (BGC) characterization. ResultsTwo major clades dominated by Oxford STs 758, 208, 417, and 369 were identified. Resistome profiling uncovered 128 distinct resistome profiles (combinations of genes) and 44 emerging antimicrobial resistance genes (ARGs), with an increased number of resistance genes in the strains obtained during the pandemic. Virulome analysis revealed enrichment of metabolic adaptation genes (argG, carA, ilvC) in MIQ strains. Mobilome profiling demonstrated enrichment of ISAbA1 and ISAbA3 elements, known to mobilize carbapenemase genes. BGC analysis showed conserved siderophores involved in virulence, alongside diversification of the secondary metabolite repertoires in MIQ genomes. Additional observations included geographic mixing of clades across Jalisco, Aguascalientes, and Mexico City and referral bias toward carbapenemase-positive isolates. ConclusionThe genomic landscape of A. baumannii in Mexico has diversified post-COVID, with evidence of inter-regional transmission, referral bias, virulome expansion, mobilome-driven ARG dissemination, and metabolic adaptation. These findings underscore the urgent need for coordinated genomic surveillance, functional and clinical validation of adaptation signals, and regionally integrated infection control strategies to mitigate resistance trajectories. Graphical abstractIntegrative genomic profiling of A. baumannii isolates from Mexico. Workflow summarizing the analysis of 194 genomes (147 historic public genomes, 47 novel MIQ strains). Clinical isolates were identified by MALDI Biotyper and tested with BD Phoenix M50. Whole genome sequencing enabled phylogenetic and MLST analyses, resistome and virulome profiling, mobilome characterization, and BGC identification using BIGSCAPE and antiSMASH. Outputs include phylogenetic clustering, resistance/virulence gene distributions, and biosynthetic potential across Mexican regions. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=84 SRC="FIGDIR/small/712163v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@74c87borg.highwire.dtl.DTLVardef@1160aa7org.highwire.dtl.DTLVardef@1564c1org.highwire.dtl.DTLVardef@89e91b_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

MORTALITY-ASSOCIATED SARS-COV-2 GENOMIC VARIANTS FROM PATIENTS HOSPITALIZED FOR SEVERE PNEUMONIA IN AGUASCALIENTES, MEXICO FROM 2020 TO 2023

BackgroundThe SARS-CoV-2 virus has caused a global health crisis, resulting in a significant loss of human lives. It is essential to report disease and mutation associations to provide ideas for public health interventions and preventive measures. MethodsIn this study, to determine the association between genomic variants and the severity of pneumonia caused by SARS-CoV-2, a sequencing analysis of 150 patient samples with confirmed COVID-19 was conducted. These samples were collected between 2021 and 2023 and isolated in Aguascalientes, Mexico. ResultsThe patient cohort had males and females ranging from 0 to 91 years old. Males accounted for 66% of the population analyzed. The Delta variant was the most prevalent lineage associated with deaths in 2021-2022, while the B.1.1.529 lineages emerged in mid-2022. Currently, the XBB lineage is the most commonly identified in Mexico. New mutations L95M and L46M in ORF 8 and ORF 9 were discovered in 30% and 20% of the sequences and are uniquely present in the studied population. These mutations are positively associated with patient death. ConclusionsThis study provides valuable data to aid in understanding the evolution of SARS-CoV-2 in specific populations and explores the severity of the disease and mutation correlations.

molecular biology↗

Genome mining of Streptomyces for the discovery of low-resistance antibiotics

2.Antimicrobial resistance is considered one of the top ten global health crises, which requires discovering and developing antibiotics with low resistance. Historically, Streptomyces bacteria are well-known for adapting to their complex environment by accumulating numerous clusters of specialized metabolites, some of which remain inactive in laboratory settings. The genomic revolution significantly increased their potential, complementing laboratory practices, and allowing for the discovery of antimicrobials associated with this biosynthetic machinery that are not constitutively produced. In the current study, we used the latest bioinformatics analyses to improve upon these predictions for Streptomyces genomes, and to identify low-resistance novel antimicrobial candidates. Our integrated pipeline used antiSMASH, BiG- SCAPE/EFI-EST, BiG-FAM, and additional tools and identified 326 novel BGCs and 67 peptides with antimicrobial potential. Further exploration of ribosomally synthesized and post-translationally modified peptides (RiPPs) revealed diverse chemical structures and suggested new mechanisms of action. Artificial intelligence platforms, such as MACREL, predicted the antimicrobial activity of the identified peptides, offering a comprehensive strategy for discovering bioactive compounds. Their low-resistance potential was estimated on a case-by-case basis. This study showcases the extensive genomic potential of Streptomyces, providing valuable insights for future antibiotic discovery efforts. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=118 SRC="FIGDIR/small/573565v1_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@1d8e6c6org.highwire.dtl.DTLVardef@116fa1eorg.highwire.dtl.DTLVardef@17edca5org.highwire.dtl.DTLVardef@1c7e6d7_HPS_FORMAT_FIGEXP M_FIG C_FIG 3. Impact statementExploring the potential applications of microorganisms is essential in fields like medicine, ecology, and biotechnology. Genomics is an invaluable tool that can uncover secondary metabolites with various applications in these fields. To this end, we conducted a detailed analysis of 388 complete genomes of Streptomyces, with a focus on identifying new biosynthetic gene clusters (BGCs) and antimicrobial peptides. Our analysis involved the use of various tools, including AntiSMASH, BiG-SCAPE, and reference databases like MiBIG and BiG-FAM, to unravel the diversity of these biosynthetic systems. We established a manually curated database and a robust pipeline for identifying valuable compounds, which allowed us to prioritize 326 BGCs with novel and diverse biosynthetic machinery. These unique insights into the genomic richness of Streptomyces will serve as a valuable guide for future antibiotic discovery efforts, facilitating the selection of strains that can produce new natural products. Moreover, our approach also helped us identify 67 potential antimicrobial peptides, including some belonging to the newly discovered Class V lanthipeptides, highlighting the diversity and promise of these compounds. Our work offers a glimpse into the potential of genomics in identifying important molecules and provides a framework for future studies in this field. Data summaryBig tables and special files can be found in Zenodo, under the following link In there, the following objects are included: O_LISupplementary Table 1: a spreadsheet with nine tables: (Table S1) Accession numbers and genomic characteristics of the genomes used in this study; (Table S2) summary of predicted Biosynthetic Gene Clusters (BGCs) for each genome; (Table S3) summary of the distribution of BGC types present in Streptomyces genomes; (Table S4) IDs and strains of MiBIG BGCs; (Table S5) All information regarding the database of peptides with antimicrobial activity; (Table S6) Data of BGCs recovered after the analysis of MiBIG and BiG-FAM; (Table S7) Complete and potentially novel BGC data used for the creation of the SSN with EFI-EST; (Table S8) Data predicting potential antimicrobial activity using MACREL v1.2.0; (Table S9) Data of predicted peptides with positive antimicrobial activity. These data were used to create the graph showing the distribution of RiPPs classes within these peptides. C_LIO_LISupplementary Data 1: a folder containing all .gbk files for the BGCs predicted by antiSMASH and MiBIG. These files were used as input for BiG-SCAPE (https://drive.google.com/file/d/1VGWJo9rsF429IUFf2g-tqs_NfBicNX91/view?usp=drive_link). C_LIO_LISupplementary Data 2: amino acid sequences of the mined and reference peptides (from the database built into this work) in .fasta format. C_LIO_LISupplementary Table 2: a spreadsheet with five tables: Data from the evaluation of the prediction of antimicrobial activity with five different AIs through five comparisons of the created database (Table S1-Macrel); (Table S2-CAMPR3); (Table S3-AMP Scanner); (Table S4-AmPEP); (Table S5-AL4AMP). C_LIO_LISupplementary Figure 1: results of the predictive performance analysis (script: https://github.com/Bert-IQ/ripps-classification). C_LI

genomics↗