Selective Pressure by Rifampicin Modulates Mutation Rates and Evolutionary Trajectories of Mycobacterial Genomes

Resistance to the frontline antibiotic rifampicin constitutes a challenge to the treatment and control of tuberculosis. Here, we analyzed the mutational landscape of Mycobacterium smegmatis during long-term evolution with increasing concentrations of rifampicin, using a mutation accumulation assay combined with whole-genome sequencing. Antibiotic treatment enhanced the acquisition of mutations, doubling the genome-wide mutation rate of the wild-type cells. While antibiotic exposure led to extinction of almost all wild-type lines, the hypermutable phenotype of the ΔnucS mutant strain (noncanonical mismatch repair deficient) provided an efficient response to the antibiotic, leading to high rates of survival. This adaptative advantage resulted in the emergence of higher levels of rifampicin resistance, an accelerated acquisition of drug resistance mutations in rpoB (β RNA polymerase), and a wider diversity of evolutionary pathways that led to drug resistance. Finally, this approach revealed a subset of adaptive genes under positive selection with rifampicin that could be associated with the development of antibiotic resistance. IMPORTANCE Rifampicin is the most important first-line antibiotic against mycobacterial infections, including tuberculosis, one of the top causes of death worldwide. Acquisition of rifampicin resistance constitutes a major global public health problem that makes the control of the disease challenging. Here, we performed an experimental evolution assay under antibiotic selection to analyze the response and adaptation of mycobacteria, leading to the acquisition of rifampicin resistance. This approach explored the total number of mutations that arose in the mycobacterial genomes under long-term rifampicin exposure, using whole-genome sequencing. Our results revealed the effect of rifampicin at a genomic level, identifying different mechanisms and multiple pathways leading to rifampicin resistance in mycobacteria. Moreover, this study detected that an increase in the rate of mutations led to enhanced levels of drug resistance and survival. In summary, all of these results could be useful to understand and prevent the emergence of drug-resistant isolates in mycobacterial infections.This research was funded by MCIN/AEI/10.13039/501100011033, grant PID2020-112865RB-I00, and Instituto de Salud Carlos III, grant FIS PI17/00159 (ISCIII/FEDER, UE). E.C.-S. is the recipient of a PFIS predoctoral research fellowship (FI18/00036) cofinanced by the Instituto de Salud Carlos III and the European Social Fund. A.C.-G. acknowledges financial support from the Spanish State Research Agency, AEI/10.13039/501100011033, through the “Severo Ochoa” Program for Centers of Excellence in R&D (SEV-2013-0347, SEV-2017-0712). Editorial assistance was provided by Stuart L. Rulten. Statistical consultancy was provided by Applied Statistical Department-SGAI-CSIC.S

SARS-CoV-2 outbreak on a Spanish mink farm: epidemiological, molecular, and pathological studies

Farmed minks have been reported to be highly susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and may represent a risk to humans. In this study, we describe the first outbreak of SARS-CoV-2 occurred on a mink farm in Spain, between June and July 2020, involving 92,700 animals. The outbreak started shortly after some farm workers became seropositive for SARS-CoV-2. Minks showed no clinical signs compatible with SARS-CoV-2 infection throughout the outbreak. Samples from 98 minks were collected for histopathological, serological, and molecular studies. Twenty out of 98 (20.4%) minks were positive by RT-qPCR and 82 out 92 (89%) seroconverted. This finding may reflect a rapid spread of the virus at the farm with most of the animals overcoming the infection. Additionally, SARS-CoV-2 was detected by RT-qPCR in 30% of brain samples from positive minks. Sequencing analysis showed that the mink sequences were not closely related with the other mink SARS-CoV-2 sequences available, and that this mink outbreak has its probable origin in one of the genetic variants that were prevalent in Spain during the first COVID-19 epidemic wave. Histological studies revealed bronchointerstitial pneumonia in some animals. Immunostaining of viral nucleocapsid was also observed in nasal turbinate tissue. Farmed minks could therefore constitute an important SARS-CoV-2 reservoir, contributing to virus spread among minks and humans. Consequently, continuous surveillance of mink farms is needed

Evolutionary and phenotypic characterization of two spike mutations in European lineage 20E of SARS-CoV-2.

We have detected two mutations in the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at amino acid positions 1163 and 1167 that appeared independently in multiple transmission clusters and different genetic backgrounds. Furthermore, both mutations appeared together in a cluster of 1,627 sequences belonging to clade 20E. This cluster is characterized by 12 additional single nucleotide polymorphisms but no deletions. The available structural information on the S protein in the pre- and postfusion conformations predicts that both mutations confer rigidity, which could potentially decrease viral fitness. Accordingly, we observed reduced infectivity of this spike genotype relative to the ancestral 20E sequence in vitro, and the levels of viral RNA in nasopharyngeal swabs were not significantly higher. Furthermore, the mutations did not impact thermal stability or antibody neutrali- zation by sera from vaccinated individuals but moderately reduce neutralization by convalescent-phase sera from the early stages of the pandemic. Despite multi- ple successful appearances of the two spike mutations during the first year of SARS-CoV-2 evolution, the genotype with both mutations was displaced upon the expansion of the 20I (Alpha) variant. The midterm fate of the genotype investi- gated was consistent with the lack of advantage observed in the clinical and ex- perimental data

The SeqCOVID-Spain consortium: unravelling the dynamics of the COVID-19 first epidemic wave in Spain

Póster presentado a la Applied Bioinformatics and Public Health Microbiology 2021 Virtual Conference, celebrada del 5 al 7 de mayo de 2021.The COVID-19 pandemic has shaken the world since the beginning of 2020. Spain is among the European countries with the highest incidence of the disease during the first pandemic wave. We established a multidisciplinary consortium to monitor and study the evolution of the epidemic, with the aim of contributing to decision making and stopping rapid spreading across the country. We present the results for 2170 sequences from the first wave of the SARS-Cov-2 epidemic in Spain, representing 12% of diagnosed cases until 14th March. This effort allows us to document at least 500 initialintroductions, between early February-March from multiple international sources. Importantly, we document the early raise of two dominant genetic variants in Spain (Spanish Epidemic Clades), named SEC7 and SEC8, likely amplified by superspreading events. In sharp contrast to other non Asian countries those two variants were closely related to the initial variants of SARS-CoV-2 described in Asia and represented 40% of the genome sequences analyzed. The two dominant SECs were widely spread across the country compared to other genetic variants with SEC8 reaching a 60% prevalence just before the lockdown. Employing Bayesian phylodynamic analysis, we inferred a reduction in the effective reproductive number of these two SECs from around 2.5 to below 0.5 after the implementation of strict public-health interventions in mid-March. The effects of lockdown on the genetic variants of the virus are reflected in the general replacement of pre-existing SECs by a new variant at the beginning of the summer season. Our results reveal a significant difference in the genetic makeup of the epidemic in Spain and support the effectiveness of lockdown measures in controlling virus spread even for the most successful genetic variants.This work was funded by the Instituto de Salud Carlos III project COV20/00140, Spanish National Research Council project CSIC-COV19-021, Ministerio de Ciencia PID2019-104477RB-I00 and ERC StG 638553 to IC, and BFU2017-89594R to FGC. MC is supported by Ramón y Cajal program from Ministerio de Ciencia and grants RTI2018-094399-A-I00 and SEJI/2019/011.Peer reviewe

Spread of a SARS-CoV-2 variant through Europe in the summer of 2020.

Following its emergence in late 2019, the spread of SARS-CoV-21,2 has been tracked by phylogenetic analysis of viral genome sequences in unprecedented detail3–5. Although the virus spread globally in early 2020 before borders closed, intercontinental travel has since been greatly reduced. However, travel within Europe resumed in the summer of 2020. Here we report on a SARS-CoV-2 variant, 20E (EU1), that was identified in Spain in early summer 2020 and subsequently spread across Europe. We find no evidence that this variant has increased transmissibility, but instead demonstrate how rising incidence in Spain, resumption of travel, and lack of effective screening and containment may explain the variant’s success. Despite travel restrictions, we estimate that 20E (EU1) was introduced hundreds of times to European countries by summertime travellers, which is likely to have undermined local efforts to minimize infection with SARS-CoV-2. Our results illustrate how a variant can rapidly become dominant even in the absence of a substantial transmission advantage in favourable epidemiological settings. Genomic surveillance is critical for understanding how travel can affect transmission of SARS-CoV-2, and thus for informing future containment strategies as travel resumes. © 2021, The Author(s), under exclusive licence to Springer Nature Limited

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of SARS-CoV-2 genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three available genomic nomenclature systems for SARS-CoV-2 to all sequence data from the WHO European Region available during the COVID-19 pandemic until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation. We provide a comparison of the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2.Peer reviewe

Spread of a SARS-CoV-2 variant through Europe in the summer of 2020

[EN] Following its emergence in late 2019, the spread of SARS-CoV-21,2 has been tracked by phylogenetic analysis of viral genome sequences in unprecedented detail3,4,5. Although the virus spread globally in early 2020 before borders closed, intercontinental travel has since been greatly reduced. However, travel within Europe resumed in the summer of 2020. Here we report on a SARS-CoV-2 variant, 20E (EU1), that was identified in Spain in early summer 2020 and subsequently spread across Europe. We find no evidence that this variant has increased transmissibility, but instead demonstrate how rising incidence in Spain, resumption of travel, and lack of effective screening and containment may explain the variant’s success. Despite travel restrictions, we estimate that 20E (EU1) was introduced hundreds of times to European countries by summertime travellers, which is likely to have undermined local efforts to minimize infection with SARS-CoV-2. Our results illustrate how a variant can rapidly become dominant even in the absence of a substantial transmission advantage in favourable epidemiological settings. Genomic surveillance is critical for understanding how travel can affect transmission of SARS-CoV-2, and thus for informing future containment strategies as travel resumes.S

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three genomic nomenclature systems to all sequence data from the World Health Organization European Region available until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation, compare the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2

The first wave of the COVID-19 epidemic in Spain was associated with early introductions and fast spread of a dominating genetic variant

SeqCOVID-Spain consortium: Álvaro Chiner-Oms, Irving Cancino-Muñoz, Mariana G. López, Manuela Torres-Puente, Inmaculada Gómez-Navarro, Santiago Jiménez-Serrano, Jordi Pérez-Tur, Darío García de Viedma, Laura Pérez-Lago, Marta Herranz, Jon Sicilia, Pilar Catalán-Alonso, Julia Suárez González, Patricia Muñoz, Mireia Coscolla, Paula Ruiz-Rodríguez, Fernando González-Candelas, Iñaki Comas, Lidia Ruiz-Roldán, María Alma Bracho, Neris García-González, Llúcia Martínez Priego, Inmaculada Galán-Vendrell, Paula Ruiz-Hueso, Griselda De Marco, María Loreto Ferrús-Abad, Sandra Carbó-Ramírez, Giuseppe D’Auria, Galo Adrian Goig, Juan Alberola, Jose Miguel Nogueira, Juan José Camarena, David Navarro, Eliseo Albert, Ignacio Torres, Maitane Aranzamendi Zaldumbide, Óscar Martínez Expósito, Nerea Antona Urieta, María de Toro, María Pilar Bea-Escudero, Jose Antonio Boga, Cristian Castelló-Abietar, Susana Rojo-Alba, Marta Elena Álvarez-Argüelles, Santiago Melón, Elisa Martró, Antoni E. Bordoy, Anna Not, Adrián Antuori, Anabel Fernández-Navarro, Andrés Canut-Blasco, Silvia Hernáez Crespo, Maria Luz Cordón Rodríguez, Maria Concepción Lecaroz Agara, Carmen Gómez-González, Amaia Aguirre-Quiñonero, José Israel López-Mirones, Marina Fernández-Torres, Maria Rosario Almela-Ferrer, Ana Carvajal, Juan Miguel Fregeneda-Grandes, Héctor Argüello, Gustavo Cilla Eguiluz, Milagrosa Montes Ros, Luis Piñeiro Vázquez, Ane Sorarrain, José María Marimón, José J. Costa-Alcalde, Rocío Trastoy, Gema Barbeito Castiñeiras, Amparo Coira, María Luisa Pérez del Molino, Antonio Aguilera, Begoña Palop-Borrás, Inmaculada de Toro Peinado, Maria Concepción Mediavilla Gradolph, Mercedes Pérez-Ruiz, Mirian Fernández-Alonso, Jose Luis del Pozo, Oscar González-Recio, Mónica Gutiérrez-Rivas, Jovita Fernández-Pinero, Miguel Ángel Jiménez Clavero, Begoña Fuster Escrivá, Concepción Gimeno Cardona, María Dolores Ocete Mochón, Rafael Medina-Gonzalez, José Antonio Lepe, Verónica González Galán, Ángel Rodríguez-Villodres, Nieves Gonzalo Jiménez, Jordi Reina, Carla López-Causapé, Maria Dolores Gómez-Ruiz, Eva M. Gonzalez-Barbera, José Luis López-Hontangas, Vicente Martín, Antonio J. Molina, Tania Fernandez-Villa, Ana Milagro Beamonte, Nieves Felisa Martínez-Cameo, Yolanda Gracia-Grataloup, Rosario Moreno-Muñoz, Maria Dolores Tirado Balaguer, José María Navarro-Marí, Irene Pedrosa-Corral, Sara Sanbonmatsu-Gámez, Antonio Oliver, Mónica Parra Grande, Bárbara Gómez Alonso, Francisco José Arjona Zaragozí, Maria Carmen Pérez González, Francisco Javier Chamizo López, Ana Bordes-Benítez, Núria Rabella, Ferran Navarro, Elisenda Miró, Antonio Rezusta, Alexander Tristancho, Encarnación Simarro Córdoba, Julia Lozano-Serra, Lorena Robles Fonseca, Álex Soriano, Francisco Javier Roig Sena, Hermelinda Vanaclocha Luna, Isabel Sanmartín, Daniel García-Souto, Ana Pequeño-Valtierra, Jose M. C. Tubio, Javier Temes, Jorge Rodríguez-Castro, Martín Santamarina García, Manuel Rodríguez-Iglesias, Fátima Galán-Sanchez, Salud Rodríguez-Pallares, José Manuel Azcona-Gutiérrez, Miriam Blasco-Alberdi, Alfredo Mayor, Alberto L. García-Basteiro, Gemma Moncunill, Carlota Dobaño, Pau Cisteró, Oriol Mitjà, Camila González-Beiras, Martí Vall-Mayans, Marc Corbacho-Monné, Andrea Alemany, Cristina Muñoz-Cuevas, Guadalupe Rodríguez-Rodríguez, Rafael Benito, Sonia Algarate, Jessica Bueno, Andrea Vergara-Gómez, Miguel J. Martínez, Jordi Vila, Elisa Rubio, Aida Peiró-Mestres, Jessica Navero-Castillejos, David Posada, Diana Valverde, Nuria Estévez, Iria Fernández-Silva, Loretta de Chiara, Pilar Gallego-García, Nair Varela, Ulises Gómez-Pinedo, Mónica Gozalo-Margüello, Maria Eliecer Cano García, José Manuel Méndez-Legaza, Jesus Rodríguez-Lozano, María Siller, Daniel Pablo-Marcos, Maria Montserrat Ruiz-García, Antonio Galiana, Judith Sánchez-Almendro, Maria Isabel Gascón Ros, Cristina Juana Torregrosa-Hetland, Eva María Pastor Boix, Paloma Cascales Ramos, Pedro Luis Garcinuño Enríquez, Salvador Raga Borja, Julia González Cantó, Olalla Martínez Macias, Adolfo de Salazar, Laura Viñuela González, Natalia Chueca, Federico García, Cristina Gómez-Camarasa, Amparo Farga Martí, Rocío Falcón, Victoria Domínguez-Márquez, Anna M. Planas, Israel Fernández-Cádenas, Maria Ángeles Marcos, Carmen Ezpeleta, Ana Navascués, Ana Miqueleiz Zapatero, Manuel Segovia, Antonio Moreno-Docón, Esther Viedma, Raúl Recio Martínez, Irene Muñoz-Gallego, Sara Gonzalez-Bodi, Maria Dolores Folgueira, Jesús Mingorance, Elias Dahdouh, Fernando Lázaro-Perona, María Rodríguez-Tejedor, María Pilar Romero-Gómez, Julio García-Rodríguez, Juan Carlos Galán, Mario Rodríguez-Dominguez, Laura Martínez-García, Melanie Abreu Di Berardino, Manuel Ponce-Alonso, Jose Maria González-Alba, Ivan Sanz-Muñoz, Diana Pérez San José, Maria Gil Fortuño, Juan B. Bellido-Blasco, Alberto Yagüe Muñoz, Noelia Hernández Pérez, Helena Buj Jordá, Óscar Pérez Olaso, Alejandro González Praetorius, Nora Mariela Martínez Ramírez, Aida Ramírez Marinero, Eduardo Padilla León, Alba Vilas Basil, Mireia Canal Aranda, Albert Bernet Sánchez, Alba Bellés Bellés, Eric López González, Iván Prats Sánchez, Mercè García-González, Miguel José Martínez-Lirola, Manuel Ángel Rodríguez Maresca, Maria Teresa Cabezas Fernández, María Eugenia Carrillo Gil, Maria Paz Ventero Martín, Carmen Molina Pardines, Nieves Orta Mira, María Navarro Cots, Inmaculada Vidal Catalá, Isabel García Nava, Soledad Illescas Fernández-Bermejo, José Martínez-Alarcón, Marta Torres-Narbona, Cristina Colmenarejo, Lidia García-Agudo, Jorge A. Pérez García, Martín Yago López, María Ángeles Goberna Bravo, Victoria Simón García, Gonzalo Llop Furquet, Agustín Iranzo Tatay, Sandra Moreno-Marro, Noelia Lozano Rodríguez, Amparo Broseta Tamarit, Juan José Badiola Díez, Amparo Martínez-Ramírez, Ana Dopazo, Sergio Callejas, Alberto Benguría, Begoña Aguado, Antonio Alcamí, Marta Bermejo Bermejo, Ricardo Ramos-Ruíz, Víctor Manuel Fernández Soria, Fernando Simón Soria & Mercedes Roig CardellsThe coronavirus disease 2019 (COVID-19) pandemic has affected the world radically since 2020. Spain was one of the European countries with the highest incidence during the first wave. As a part of a consortium to monitor and study the evolution of the epidemic, we sequenced 2,170 samples, diagnosed mostly before lockdown measures. Here, we identified at least 500 introductions from multiple international sources and documented the early rise of two dominant Spanish epidemic clades (SECs), probably amplified by superspreading events. Both SECs were related closely to the initial Asian variants of SARS-CoV-2 and spread widely across Spain. We inferred a substantial reduction in the effective reproductive number of both SECs due to public-health interventions (Re < 1), also reflected in the replacement of SECs by a new variant over the summer of 2020. In summary, we reveal a notable difference in the initial genetic makeup of SARS-CoV-2 in Spain compared with other European countries and show evidence to support the effectiveness of lockdown measures in controlling virus spread, even for the most successful genetic variants.This work was mainly funded by the Instituto de Salud Carlos III project COV20/00140, with additional funding by Spanish National Research Council project CSIC-COV19-021, Ministerio de Ciencia project PID2019-104477RB-100, ERC StG 638553 and ERC CoG 101001038 to I.C., and BFU2017-89594R to F.G.C. M.C. is supported by Ramón y Cajal program from Ministerio de Ciencia and grants RTI2018-094399-A-I00 and Generalitat Valenciana (Regional Government) project SEJI/2019/011. We gratefully acknowledge Hospital Universitari Vall d’Hebron, Instituto de Salud Carlos III, IrsiCaixa AIDS Research Lab and all the international researchers and institutions that submitted sequenced SARS-CoV-2 genomes to the GISAID’s EpiCov Database (Supplementary Table 1), as an important part of our analyses has been made possible by the sharing of their work. We also thank Unidad de Bioinformática y Estadística, Centro de Investigación Príncipe Felipe, for allowing us to use the Computer Cluster to perform some of the bioinformatic analysis.Peer reviewe

The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes

Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics