Corynebacterium striatum, a bacterium that is part of the normal skin microbiota, is also an opportunistic pathogen. In recent years, reports of infections and in-hospital and nosocomial outbreaks caused by antimicrobial multidrug-resistant C. striatum strains have been increasing worldwide. However, there are no studies about the genomic determinants related to antimicrobial resistance in C. striatum. This review updates global information related to antimicrobial resistance found in C. striatum and highlights the essential genomic aspects in its persistence and dissemination. The resistome of C. striatum comprises chromosomal and acquired elements. Resistance to fluoroquinolones and daptomycin are due to mutations in chromosomal genes. Conversely, resistance to macrolides, tetracyclines, phenicols, beta-lactams, and aminoglycosides are associated with mobile genomic elements such as plasmids and transposons. The presence and diversity of insertion sequences suggest an essential role in the expression of antimicrobial resistance genes (ARGs) in genomic rearrangements and their potential to transfer these elements to other pathogens. The present study underlines that the resistome of C. striatum is dynamic; it is in evident expansion and could be acting as a reservoir for ARGs.

Corynebacterium striatum, present in the microbiota of human skin and nasal mucosa, has recently emerged as a causative agent of hospital-acquired infections, notable for its resistance to multiple antimicrobials. Its mobilome comprises several mobile genetic elements, such as plasmids, transposons, insertion sequences and integrons, which contribute to the acquisition of antimicrobial resistance genes. This study analyzes the contribution of the C. striatum mobilome in the transfer and dissemination of resistance genes. In addition, integrative and conjugative elements (ICEs), essential in the dissemination of resistance genes between bacterial populations, whose role in C. striatum has not yet been studied, are examined. This study examined 365 C. striatum genomes obtained from the NCBI Pathogen Detection database. Phylogenetic and pangenome analyses were performed, the resistance profile of the bacterium was recognized, and mobile elements, including putative ICE, were detected. Bioinformatic analyses identified 20 antimicrobial resistance genes in this species, with the Ermx gene being the most predominant. Resistance genes were mainly associated with plasmid sequence regions and class 1 integrons. Although an ICE was detected, no resistance genes linked to this element were found. This study provided valuable information on the geographic spread and prevalence of outbreaks observed through phylogenetic and pangenome analyses, along with identifying antimicrobial resistance genes and mobile genetic elements that carry many of the resistance genes and may be the subject of future research and therapeutic approaches.

Neisseria meningitidis, a bacterium that colonizes in the human nasopharynx, occasionally causes invasive meningococcal disease leading to meningitis or septicemia. Different serogroups and lineages (clonal complexes) are related to the occurrence and epidemiology of N. meningitidis. Despite vaccines for most serogroups, N. meningitidis lineages causing unusual clinical manifestations and a higher fatality rate compared to other lineages have been reported in South America. The present study focused on exploring the diversity of N. meningitidis prophages from South America and their relationship with the epidemiological variables of these strains. We found a high diversity of prophages among the different clonal complexes. By comparing them with previously described N. meningitidis phages and prophages, we revealed groups of prophages sharing similar compositions, which could be useful for prophage comparison in N. meningitidis. Furthermore, we observed a high correlation between the prophage content and epidemiological features, e.g., pathogenicity or clonal complex. Additionally, a distinctive filamentous prophage named here as IMSAR-11 (Invasive Meningococci from South America Related to cc11) was identified. Interestingly, two versions of IMSAR-11, circular and chromosomally integrated, were found. Overall, this study reinforces the importance of the genomic characterization of circulating N. meningitidis lineages to generate new targets for lineage monitoring, diagnosis, or appropriateness of vaccine development. Further studies are necessary to understand the role of these prophages in the persistence, dispersal, and virulence of N. meningitidis in the world.

Identifying the microbial taxa that structure assemblages in response to local disturbances along the Chilean Patagonian coast is critical for understanding community reorganization and ecological risk in this vulnerable marine environment. Here, we examined benthic microbial interactions across sixteen sites spanning 42–44°S in the Inner Sea of Chiloé and adjacent fjord systems. Using co-occurrence network analysis, we characterized spatial interaction patterns and identified keystone taxa whose relationships with environmental variables may serve as ecological indicators. The presence of keystone taxa supports the concept of microbial “seed banks,” which sustain community stability and ecosystem functionality under stress. Networks revealed structured communities dominated by niche-specialist taxa, consistent with ecological processes of niche differentiation and environmental filtering. The benthic environment was found to harbor niche-specialist taxa, including Flavobacteriaceae, Gemmataceae, Humimicrobiaceae, Clostridiaceae, and Sulfurovaceae, typically associated with organic enrichment and anthropogenic influence. These microbial families showed strong correlations with environmental gradients such as nitrate, phosphate, silicate, pH, salinity, and phaeopigments. Alpha-diversity analyses revealed greater microbial richness in FZ compared to the ISC, likely reflecting higher environmental heterogeneity and long-term adaptation to dynamic and fluctuating conditions. Beta-diversity analyses further supported the presence of distinct microbial assemblages between the two zones. Multivariate statistics and co-occurrence network analyses demonstrated that FZ communities display enhanced taxonomic interactions and greater network complexity, suggesting increased ecological stability. In contrast, microbial networks in the ISC exhibited reduced connectivity, potentially indicative of environmental stressors disrupting microbial spatial organization and network resilience. Moreover, the identification of indigenous bacterial isolates provided evidence for the presence of opportunistic host-associated pathogens, highlighting the utility of microbial biomarkers in detecting early ecological responses to human impacts. Microbial co-occurrence patterns in northern Patagonian sediments reveal shifts in community assembly and increased network complexity that may enhance resilience to perturbations. The detection of strains harboring opportunistic pathogen biomarkers highlights risks under intense anthropogenic pressures. Monitoring keystone taxa thus offers early warning of functional decline. Broader spatio-temporal assessments remain essential to clarify microbial dynamics and their implications for ecosystem health and antimicrobial resistance.

Here, we announce the genome sequences of 408 strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) obtained from nasopharyngeal swabs in the Araucanía Region, Southern Chile. The genomes obtained are valuable to expand the availability of useful genomic data for future epidemiological studies of SARS-CoV-2 in Chile and worldwide.

Macroalgae and their associated microbes form tightly integrated holobionts, yet cross‐study comparisons of epiphytic microbiomes remain constrained by heterogeneous sampling designs, primer selection, and analytical pipelines. We performed a harmonized meta‐analysis of publicly available 16S rRNA gene datasets to examine diversity, community structure, and inferred functional profiles within a common analytical framework. A structured search identified 16 studies, totaling 763 samples, from macroalgae and adjacent seawater across four oceanic regions. All datasets were reprocessed using a standardized workflow to ensure cross‐study comparability. The compiled dataset was strongly skewed towards brown macroalgae (Phaeophyceae) and the V4 region of the 16S gene, highlighting both the prominence of Laminariales in current research and the need for methodological harmonization. Within this framework, alpha diversity differed among macroalgal orders, with Fucales hosting the richest epiphytic assemblages, Desmarestiales intermediate diversity, and Laminariales the lowest, while seawater exhibited intermediate values. Community composition was structured by host taxonomic identity and sample type. Within Laminariales, thalli supported assemblages distinct from seawater, sharing a limited taxonomic core and displaying reproducible genus‐level signatures. Trait‐based functional annotation indicated enrichment of aerobic chemoheterotrophy and polysaccharide‐associated metabolisms in Laminariales communities, whereas seawater showed greater representation of nitrogen‐ and sulfur‐related processes. These findings demonstrate that cross‐study reprocessing resolves consistent host‐associated patterns and establishes a quantitative framework for future multi‐omics and experimental investigations.