Biology subjects

Cunha, M. V.

Publications and source records attributed to Cunha, M. V..

7 recordsLinked to original sources

bioRxiv2024

Phylogenetic analysis of Mycobacterium bovis Reveals Evidence Of Animal And Zoonotic Tuberculosis Transmission Between Morocco And European Countries

Livestock production is a fundamental pillar of the Moroccan economy. Infectious diseases of cattle and other species represent a significant threat to the livestock industry, animal health, and food safety and security. Bovine tuberculosis (bTB), mainly caused by Mycobacterium bovis (M. bovis), generates considerable direct and indirect economic losses, in addition to the unknown human health burden caused by zoonotic transmission. Previous studies have suggested likely M. bovis transmission links between Morocco and Southern Europe, however, limitations inherent with the methods used prevented more definitive conclusions from being drawn. In this study, we employed whole genome sequencing analysis of a large set of M. bovis isolates to better define the phylogenetic links between strains from Morocco and neighboring countries. A total of 780 M. bovis sequences representing 36 countries were included in the study. The results of SNP analysis showed a close genetic relationship between M. bovis from Morocco and each of Spain, France, Portugal and Germany, this is supported by animal trade between Morocco and these countries, in addition to the important human migration from Morocco to Europe and North America. Regarding zoonotic tuberculosis (TB) transmission, we were able to find genetic links between M. bovis isolates from cattle in Morocco and humans in Italy, Germany, and the UK. These results support our hypothesis of significant transmission of M. bovis from cattle to humans, which calls for further investigations of zoonotic TB transmission in Morocco and in other countries. The fact that no M. bovis sequences from North Africa in the present database were classified as AF1 or AF2 clonal complexes suggests that the Sahara might play a role in preventing M. bovis transmission between North Africa and Sub-Saharan Africa. Our study benefits from a large sample size and a rich dataset that includes sequences from cattle, wildlife, and humans from Morocco and neighboring countries, enabling the delineation of M. bovis transmission routes within the animal-human interface.

molecular biology↗

bioRxiv2023

The historical ecological background of West Nile virus in Portugal provides One Health opportunities into the future

West Nile (WNV) is a zoonotic arbovirus with an expanding geographical range and epidemic activity in Europe. Not having yet experienced a human-associated epidemic, Portugal remains an outlier in the Mediterranean basin. In this study, we apply ecological niche modelling informed by WNV historical evidence (1969-2022) and a multitude of environmental variables from across Portugal. We identify that ecological backgrounds compatible with WNV historical circulation are mostly restricted to the south, characterized by a warmer and drier climate, high avian diversity, specific avian species and land types. We estimate WNV ecological suitability across the country, identifying overlaps with the distributions of the three relevant hosts (humans, birds, equines) for public and animal health. From this, we propose a category-based spatial framework providing first of a kind valuable insights for future WNV surveillance under the One Health nexus. We also forecast that climate trends alone will contribute to pushing adequate WNV ecological suitability northwards, toward regions with higher human density. This unique perspective on the past, present and future ecology of WNV addresses existing national knowledge gaps, enhances our understanding of the evolving emergence of WNV, and offers opportunities to prepare and respond to the first human-associated epidemic in Portugal.

ecology↗

bioRxiv2023

Population structure and history of Mycobacterium bovis European 3 clonal complex reveal transmission across ecological corridors of unrecognised importance in Portugal

Mycobacterium bovis causes animal tuberculosis in livestock and wildlife, with an impact on animal health and production, wildlife management, and public health. In this work, we sampled a multi-host tuberculosis community from the official hotspot risk area of Portugal over 16 years, generating the largest available dataset in the country. Using phylogenetic and ecological modelling, we aimed to reconstruct the history of circulating lineages across the livestock-wildlife interface to inform intervention and the implementation of genomic surveillance within the official eradication plan. We find evidence for the co-circulation of M. bovis European 1 (Eu1), Eu2, and Eu3 clonal complexes, with Eu3 providing sufficient temporal signal for further phylogenetic investigation. The Eu3 most recent common ancestor (bovine) was dated in the 90s, subsequently transitioning to wildlife (red deer and wild boar). Isolate clustering based on sample metadata was used to inform phylogenetic inference, unravelling frequent transmission between two clusters that represent an ecological corridor of previously unrecognised importance in Portugal. The latter was associated with transmission at the livestock-wildlife interface towards locations with higher temperature and precipitation, lower agriculture and road density, and lower host densities. This is the first analysis of M. bovis Eu3 complex in Iberia, shedding light on background ecological factors underlying long-term transmission, and informing where efforts could be focused within the larger hotspot risk area of Portugal. IMPORTANCEEfforts to strengthen surveillance and control of animal tuberculosis (TB) are ongoing worlwide. Here, we developed an eco-phylodynamic framework based on discrete phylogenetic approaches informed by M. bovis whole genome sequence data representing a multi-host transmission system at the livestock-wildlife interface, within a rich ecological landscape in Portugal, to understand transmission processes and translate this knowledge into disease management benefits. We find evidence for the co-circulation of several M. bovis clades, with frequent transmission of the Eu3 lineage among cattle and wildlife populations. Most transition events between different ecological settings took place toward host, climate and land use gradients, underscoring animal TB expansion and a potential corridor of unrecognised importance for M. bovis maintenance. Results stress that animal TB is an established wildlife disease without ecological barriers, showing that control measures in place are insufficient to prevent long-distance transmission and spillover across multi-host communities, demanding new interventions targeting livestock-wildlife interactions.

genomics↗

bioRxiv2023

Rescue of Mycobacterium bovis DNA obtained from cultured strains during official surveillance of animal TB: key steps for robust whole genome sequence data generation

Epidemiological surveillance of animal tuberculosis (TB) based on whole genome sequencing (WGS) of Mycobacterium bovis has recently gained track due to its high resolution to identify infection sources, characterize the pathogen population structure, and for contact tracing. However, the workflow from bacterial isolation to sequence data analyses has several technical challenges that may severely impact the power to understand the epidemiological scenario and inform outbreak response. While trying to use archived DNA from cultured strains obtained during routine official surveillance of animal TB in Portugal, we struggled against three major challenges: the low amount of M. bovis DNA obtained from routinely processed animal samples; the lack of purity of M. bovis DNA, i.e. high levels of contamination with DNA from other organisms; and the co-occurrence of more than one M. bovis strain per sample (within-host mixed infection). The loss of an isolates genome is a missed link in transmission chain reconstruction, hampering the biological and epidemiological interpretation of data as a whole. Upon identification of these challenges, we implemented an integrated solution framework, based on whole genome amplification and a dedicated computational pipeline, to minimize their effects and recover as many genomes as possible. With the approaches described herein, we were able to recover 62 out of 100 samples that would have otherwise been lost. Based on these results, we discuss adjustments that should be made in official and research laboratories to facilitate sequential implementation of bacteriological culture, PCR, downstream genomics and computational-based methods. All of this in a time frame supporting data-driven intervention.

genomics↗

bioRxiv2021

Phylogenomics Sheds Light on the population structure of Mycobacterium bovis from a Multi-Host Tuberculosis System

Molecular analyses of Mycobacterium bovis based on spoligotyping and Variable Number Tandem Repeat (MIRU-VNTR) brought insights into the epidemiology of animal tuberculosis (TB) in Portugal, showing high genotypic diversity of circulating strains that mostly cluster within the European 2 clonal complex. The genetic relatedness of M. bovis isolates from cattle and wildlife have also suggested sustained transmission within this multi-host system. However, while previous surveillance highlighted prevalent genotypes in areas where livestock and wild ungulates are sympatric and provided valuable information on the prevalence and spatial occurrence of TB, links at the wildlife-livestock interfaces were established mainly via genotype associations. Therefore, evidence at a local fine scale of transmission events linking wildlife hosts and cattle remains lacking. Here, we explore the advantages of whole genome sequencing (WGS) applied to cattle, red deer and wild boar isolates to reconstruct the evolutionary dynamics of M. bovis and to identify putative pathogen transmission events. Whole genome sequences of 44 representative M. bovis isolates, obtained between 2003 and 2015 from three TB hotspots, were compared through single nucleotide polymorphism (SNP) variant calling analyses. Consistent with previous results combining classical genotyping with Bayesian population admixture modelling, SNP-based phylogenies support the branching of this M. bovis population into five genetic clades, three with geographic specificities, as well as the establishment of a SNPs catalogue specific to each clade, which may be explored in the future as phylogenetic markers. The core genome alignment of SNPs was integrated within a spatiotemporal metadata framework to reconstruct transmission networks, which together with inferred secondary cases, further structured this M. bovis population by host species and geographic location. WGS of M. bovis isolates from Portugal is reported for the first time, refining the spatiotemporal context of transmission events and providing further support to the key role of red deer and wild boar on the persistence of animal TB in this Iberian multi-host system.

genomics↗

bioRxiv2020

Revisiting the expression signature of pks15/1 unveils regulatory patterns controlling phenolphtiocerol and phenolglycolipid production in pathogenic mycobacteria

One of the most relevant and exclusive characteristics of mycobacteria is its cell wall, composed by mycolic acids. Amid these are two related families of glycosylated lipids, diphthioceranates and phthiocerol dimycocerosate (PDIM) and its variant phenolic glycolipids (PGL). PGL have been associated with cell wall impermeability, phagocytosis, defence against nitrosative and oxidative stress and, supposedly, biofilm formation. In bacteria from the Mycobacterium tuberculosis complex, the biosynthetic pathway of the phenolphthiocerol moiety of PGL depends upon the expression of several genes encoding type I polyketide synthases (PKS), namely ppsA-E and pks15/1 constituting the PDIM + PGL locus, highly conserved in PDIM/PGL-producing strains. Consensus has not been achieved regarding the genetic organization of pks15/1 locus and little effort has been put on the disclosure of its transcriptional signature. Here we explore publicly available datasets of transcriptome data (RNA-seq) from more than 100 experiments in 40 growth conditions to outline the transcriptional structure and signature of pks15/1 and use a differential expression approach to infer the regulatory patterns involving these and related genes. We show that pks1 is highly correlated with fadD22, Rv2949c, lppX, fadD29 and, also, pks6 and pks12, with the first three putatively integrating a polycistronic structure. We evidence dynamic heterogeneity of transcription within the genes involved in phenolphtiocerol and phenolglycolipid production, most exhibiting up-regulation upon acidic pH and antibiotic exposure and down-regulation under hypoxia, dormancy, and low/high iron concentration. We finally propose a model based on transcriptome data in which {sigma}D positively regulates pks1, pks15 and fadD22, while {sigma}B and {sigma}E factors exert negative regulation at an upper level.

genomics↗

bioRxiv2018

Yersiniabactin, Colibactin and Wider Resistome Contribute to Enhanced Virulence and Persistence of KPC-2-Producing Klebsiella pneumoniae CG258 in South America

The emergence and dissemination of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKp) is a worrisome public health issue compromising the treatment and outcome of infections caused by this pathogen. We performed a detailed virulome and resistome analysis of representative KPC- and/or CTX-M-producing K. pneumoniae belonging to clonal group (CG) 258 (sequence types ST11, ST258, ST340, ST437), circulating in Argentina, Brazil, Chile, Colombia and Peru; with further evaluation of the virulence behavior using the Galleria mellonella infection model. Genomic analysis of K. pneumoniae strains recovered from the human-animal-environment interface revealed a wide resistome characterized by the presence of genes and mutations conferring resistance to human and veterinary antibiotics, quaternary ammonium compounds (QACs) and heavy metals. Plasmid Inc typing revealed the presence of a wide diversity of replicon types with IncF, IncN, IncR and Col-like being frequently detected. Moreover, KPC-2-producing K. pneumoniae belonging to ST11 (KL-64 andKL-105) and ST340 (KL-15) carried multiple variants of distinct yersiniabactin siderophore (ybt) and/or genotoxic colibactin (clb) genes. In this regard, ICEKp3, ICEKp4 and ICEKp12 were identified in strains belonging to ST11 and ST340, recovered from Argentina, Brazil, Chile and Colombia; whereas ybt 17 and a novel ybt sequence type (YbST346) were identified together with clb in ICEKp10 structures from ST11 and ST258, from Brazil and Colombia, respectively. K. pneumoniae ST11 (ICEKp10/YbST346 and ICEKp4/ybt 10) strains killed 100% of wax moth larvae, in a similar way to hypervirulent K1/ST23 strain (ybt- and clb-negative) carrying the pLVPK-like plasmid, indicating enhanced virulence. In summary, our results indicate that yersiniabactin, colibactin and an expanded resistome have contributed to enhanced virulence and persistence of KPC-2-producing K. pneumoniae CG258 in South America. Therefore, active surveillance of hospital-associated lineages of K. pneumoniae should not only focus on clonal origin and antimicrobial resistance, but also on the virulence factors ybt and clb.

microbiology↗