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Antimicrobial resistance (AMR) is a major global public health threat, which has been largely driven by the excessive use of antimicrobials. Control measures are urgently needed to slow the trajectory of AMR but are hampered by an incomplete understanding of the interplay between pathogens, AMR encoding genes, and mobile genetic elements at a microbial level. These factors, combined with the human, animal, and environmental interactions that underlie AMR dissemination at a population level, make for a highly complex landscape. Whole-genome sequencing (WGS) and, more recently, metagenomic analyses have greatly enhanced our understanding of these processes, and these approaches are informing mitigation strategies for how we better understand and control AMR. This review explores how WGS techniques have advanced global, national, and local AMR surveillance, and how this improved understanding is being applied to inform solutions, such as novel diagnostic methods that allow antimicrobial use to be optimised and vaccination strategies for better controlling AMR. We highlight some future opportunities for AMR control informed by genomic sequencing, along with the remaining challenges that must be overcome to fully realise the potential of WGS approaches for international AMR control.

Typhoid fever epidemiology was investigated rigorously in Santiago, Chile during the 1980s, when Salmonella enterica serovar Typhi ( S . Typhi) caused seasonal, hyperendemic disease. Targeted interventions reduced the annual typhoid incidence rates from 128–220 cases/10 5 population occurring between 1977–1984 to <8 cases/10 5 from 1992 onwards. As such, Santiago represents a contemporary example of the epidemiologic transition of an industrialized city from amplified hyperendemic typhoid fever to a period when typhoid is no longer endemic. We used whole genome sequencing (WGS) and phylogenetic analysis to compare the genotypes of S . Typhi cultured from acute cases of typhoid fever occurring in Santiago during the hyperendemic period of the 1980s (n = 74) versus the nonendemic 2010s (n = 80) when typhoid fever was rare. The genotype distribution between “historical” (1980s) isolates and “modern” (2011–2016) isolates was similar, with genotypes 3.5 and 2 comprising the majority of isolations, and 73/80 (91.3%) of modern isolates matching a genotype detected in the 1980s. Additionally, phylogenomically ‘ancient’ genotypes 1.1 and 1.2.1, uncommon in the global collections, were also detected in both eras, with a notable rise amongst the modern isolates. Thus, genotypes of S . Typhi causing acute illness in the modern nonendemic era match the genotypes circulating during the hyperendemic 1980s. The persistence of historical genotypes may be explained by chronic typhoid carriers originally infected during or before the 1980s.

The emergence of XDR Salmonella Typhi in Pakistan has left azithromycin as the only viable oral treatment option. Here, we report the detection of an azithromycin resistance-associated mutation in one S. Typhi isolate. This finding is important because any possible spread of azithromycin resistance in S. Typhi isolates would make it nearly impossible to treat in outpatient settings due to the need of injectable antibiotics. Our findings also signify the importance of introduction of typhoid conjugate vaccine in regions of endemicity such as Pakistan. Antimicrobial resistance is an ongoing issue in the treatment of typhoid fever. Resistance to first-line antimicrobials and extensively drug resistant (XDR) Salmonella Typhi isolates in Pakistan have left azithromycin as the only remaining effective oral treatment. Here, we report the emergence of organisms with a single point mutation in acrB gene, implicated in azithromycin resistance, in a S. Typhi isolate from Pakistan. The isolation of this organism is worrisome and highlights the significance of the introduction of typhoid conjugate vaccine in South Asia. IMPORTANCE The emergence of XDR Salmonella Typhi in Pakistan has left azithromycin as the only viable oral treatment option. Here, we report the detection of an azithromycin resistance-associated mutation in one S. Typhi isolate. This finding is important because any possible spread of azithromycin resistance in S. Typhi isolates would make it nearly impossible to treat in outpatient settings due to the need of injectable antibiotics. Our findings also signify the importance of introduction of typhoid conjugate vaccine in regions of endemicity such as Pakistan.

Little is known about the genetic diversity of Salmonella enterica serovar Typhi ( S . Typhi) circulating in Latin America. It has been observed that typhoid fever is still endemic in this part of the world; however, a lack of standardized blood culture surveillance across Latin American makes estimating the true disease burden problematic. The Colombian National Health Service established a surveillance system for tracking bacterial pathogens, including S . Typhi, in 2006. Here, we characterized 77 representative Colombian S . Typhi isolates collected between 1997 and 2018 using pulse field gel electrophoresis (PFGE; the accepted genotyping method in Latin America) and whole genome sequencing (WGS). We found that the main S . Typhi clades circulating in Colombia were clades 2.5 and 3.5. Notably, the sequenced S . Typhi isolates from Colombia were closely related in a global phylogeny. Consequently, these data suggest that these are endemic clades circulating in Colombia. We found that AMR in S . Typhi in Colombia was uncommon, with a small subset of organisms exhibiting mutations associated with reduced susceptibility to fluoroquinolones. This is the first time that S . Typhi isolated from Colombia have been characterized by WGS, and after comparing these data with those generated using PFGE, we conclude that PFGE is unsuitable for tracking S . Typhi clones and mapping transmission. The genetic diversity of pathogens such as S . Typhi is limited in Latin America and should be targeted for future surveillance studies incorporating WGS.

Routine clinical microbiology data are widely used for antimicrobial resistance (AMR) surveillance, but data availability and quality vary. In this Perspective, we explore the technical challenges of utilising routine data to inform action at various levels, and summarise emerging open-source technical solutions for hospital-level data collection, aggregation, and sharing. We highlight a need for agreed-upon data standards, and tools that support both facility-level and public health surveillance.

Antimicrobial resistance (AMR) poses a serious threat to the clinical management of typhoid fever. AMR in Salmonella Typhi ( S . Typhi) is commonly associated with the H58 lineage, a lineage that arose comparatively recently before becoming globally disseminated. To better understand when and how H58 emerged and became dominant, we performed detailed phylogenetic analyses on contemporary genome sequences from S . Typhi isolated in the period spanning the emergence. Our dataset, which contains the earliest described H58 S . Typhi organism, indicates that ancestral H58 organisms were already multi-drug resistant (MDR). These organisms emerged spontaneously in India in 1987 and became radially distributed throughout South Asia and then globally in the ensuing years. These early organisms were associated with a single long branch, possessing mutations associated with increased bile tolerance, suggesting that the first H58 organism was generated during chronic carriage. The subsequent use of fluoroquinolones led to several independent mutations in gyrA . The ability of H58 to acquire and maintain AMR genes continues to pose a threat, as extensively drug-resistant (XDR; MDR plus resistance to ciprofloxacin and third generation cephalosporins) variants, have emerged recently in this lineage. Understanding where and how H58 S . Typhi originated and became successful is key to understand how AMR drives successful lineages of bacterial pathogens. Additionally, these data can inform optimal targeting of typhoid conjugate vaccines (TCVs) for reducing the potential for emergence and the impact of new drug-resistant variants. Emphasis should also be placed upon the prospective identification and treatment of chronic carriers to prevent the emergence of new drug resistant variants with the ability to spread efficiently. A phylogenetic analysis of Salmonella Typhi isolated from returning travelers to the United Kingdom between 1980 and 1995 suggests that H58 emerged from a chronic carrier in India in 1987 before spreading globally and was already multidrug resistant.

[Display omitted] Rotavirus disease is a leading global cause of mortality and morbidity in children under 5years of age. The effectiveness of the two globally used oral rotavirus vaccines quickly became apparent when introduced into both developed and developing countries, with significant reductions in rotavirus-associated mortality and hospitalizations. However, the effectiveness and impact of the vaccines is reduced in developing country settings, where the burden and mortality is highest. New rotavirus vaccines, including live oral rotavirus candidates and non-replicating approaches continue to be developed, with the major aim to improve the global supply of rotavirus vaccines and for local implementation, and to improve vaccine effectiveness in developing settings. This review provides an overview of the new rotavirus vaccines in development by developing country manufacturers and provides a rationale why newer candidates continue to be explored. It describes the new live oral rotavirus vaccine candidates as well as the non-replicating rotavirus vaccines that are furthest along in development.

The Antimicrobial Resistance - Genomes, Big Data and Emerging Technologies Conference explored key topics including measuring the burden of AMR, global public health pathogen genomics infrastructure and surveillance, translation and implementation of genomics for AMR control, use of techniques such as wastewater surveillance, mathematical and statistical modelling, and Artificial Intelligence (AI) to aid understanding of AMR. This report describes research presented during plenary sessions and discussions, keynote presentations and posters.

The Typhoid Surveillance in Africa Program (TSAP) and the Severe Typhoid Fever in Africa (SETA) program have refined our understanding of age and geographic distribution of typhoid fever and other invasive salmonelloses in Africa and will help inform future typhoid control strategies, namely, introduction of typhoid conjugate vaccines.

Yersinia pestis is the causative agent of plague – the archetypal bacterial pandemic disease. Plague remains endemic in several countries in Africa, South America, and Asia, posing high risks of zoonotic spill-over and epidemic spread or threat of deliberate release. Plague vaccine development remains a priority for pandemic preparedness initiatives but generating sufficient field data for vaccine licensure is challenging. Controlled human infection studies have been deployed to test candidate vaccines against diseases with low and sporadic incidences of outbreaks where field trials are difficult. Typically, such studies use live attenuated or vaccine-type strains to measure clinical or microbiological end points of interest. To assess the feasibility of conducting a human vaccine-challenge study for Y. pestis, we hosted a one-day expert consultation workshop in January 2025. The aim was to discuss the practical, regulatory landscape and future use-case of such a model. We invited attendees from academia, industry, regulatory bodies, funders, and other stakeholders with expertise in Y. pestis biology and infection. The workshop combined presentations with breakout discussions and was divided into five sessions: i) Introduction to live attenuated Y. pestis vaccines; ii) Update of the contemporary plague vaccine landscape; iii) Assessment of biosafety and bio-security considerations; iv) Clinical and ethical considerations and v) public perceptions. Several challenges were identified, and potential strategies to address them were discussed. This perspective builds on this workshop and lays the foundation for a collaborative consortium to develop a Y. pestis vaccine challenge model. Next steps include early-stage public engagement, strain characterization, and regulatory discussions to define how data from these studies could be used for assessing vaccine efficacy. Our vision is to establish a global network dedicated to advancing new vaccine technologies for an ancient disease.