Ray Izquierdo Lara

Mr. Ray Izquierdo Lara


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 November 2025 in Nature Communications
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NWNathalie Worp
Nathalie Worp
David NieuwenhuijseDavid Nieuwenhuijse
David Nieuwenhuijse
RLRay Izquierdo Lara
Ray Izquierdo Lara
CSClaudia M. E. Schapendonk
Claudia M. E. Schapendonk
CBChristian Brinch
Christian Brinch
Miranda de GraafMiranda de Graaf
Miranda de Graaf
Understanding global viral dynamics is critical for public health. Traditional surveillance focuses on individual pathogens and symptomatic cases, which may miss asymptomatic infections or newly emerging viruses, delaying detection and response. Wastewater-based epidemiology has been used to track pathogens through targeted molecular assays, but its reliance on predefined targets limits detection of the full viral spectrum. Here, we analyse longitudinal wastewater samples from 62 cities across six continents (2017–2019) using metagenomics and capture-based sequencing with probes targeting viruses associated with gastrointestinal disease. We detect over 2500 viral species spanning 122 families, many with human, animal, or plant health relevance. The bacteriophage family Microviridae and plant virus family Virgaviridae dominate the metagenomic dataset, while Astroviridae and Picornaviridae prevail in the capture-based sequence dataset. Virus distributions are broadly similar across continents at the family and genus levels, yet distinct city-level fingerprints reveal geographical and temporal variation, enabling spatiotemporal surveillance of viruses such as astroviruses and enteroviruses. Global wastewater-based epidemiology enables early detection of emerging viruses, including Echovirus 30 in Europe and Tomato brown rugose fruit virus. These findings highlight the potential of wastewater sequencing for the early detection of emerging viruses and population-wide virome monitoring across diverse hosts.

23 November 2017 in Virology Journal
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ACAna Chumbe
Ana Chumbe
RLRay Izquierdo Lara
Ray Izquierdo Lara
Katherine Ivette Calderón MayoKatherine Ivette Calderón Mayo
Katherine Ivette Calderón Mayo
MFManolo Fernandez
Manolo Fernandez
VVVikram N. Vakharia
Vikram N. Vakharia
Newcastle disease is one of the most important infectious diseases of poultry, caused by Newcastle disease virus (NDV). This virus is distributed worldwide and it can cause severe economic losses in the poultry industry due to recurring outbreaks in vaccinated and unvaccinated flocks. Protection against NDV in chickens has been associated with development of humoral response. Although hemagglutination inhibition (HI) assay and ELISA do not corroborate the presence of neutralizing antibodies (nAbs); they are used to measure protection and immune response against NDV. In this study, we established a system to recover a recombinant NDV (rLS1) from a cloned cDNA, which is able to accept exogenous genes in desired positions. An enhanced green fluorescent protein (eGFP) gene was engineered in the first position of the NDV genome and we generated a recombinant NDV carrying eGFP. This NDV- eGFP reporter virus was used to develop an eGFP-based neutralization test (eGFP-NT), in which nAbs titers were expressed as the reciprocal of the highest dilution that expressed the eGFP. The eGFP-NT gave conclusive results in 24 h without using any additional staining procedure. A total of 57 serum samples were assayed by conventional neutralization (NT) and eGFP-NT. Additionally, HI and a commercial ELISA kit were evaluated with the same set of samples. Although HI (R 2 = 0.816) and ELISA (R 2 = 0.791) showed substantial correlation with conventional NT, eGFP-NT showed higher correlation (R 2 = 0.994), indicating that eGFP-NT is more accurate method to quantify nAbs. Overall, the neutralization test developed here is a simple, rapid and reliable method for quantitation of NDV specific nAbs. It is suitable for vaccine studies and diagnostics.

14 November 2019 in PLOS ONE
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RLRay Izquierdo Lara
Ray Izquierdo Lara
ACAna Chumbe
Ana Chumbe
Katherine Ivette Calderón MayoKatherine Ivette Calderón Mayo
Katherine Ivette Calderón Mayo
MFManolo Fernández-Díaz
Manolo Fernández-Díaz
VVVikram N Vakharia
Vikram N Vakharia
Although typical Newcastle disease virus (NDV) vaccines can prevent mortality, they are not effective in preventing viral shedding. To overcome this, genotype-matched vaccines have been proposed. To date, this approach has never been tested against genotype XII strains. In this study, we generated and assessed the protection against genotype XII challenge of two chimeric NDV vaccine strains (rLS1-XII-1 and rLS1-XII-2). The rLS1-XII-1 virus has the complete fusion protein (F) and the hemagglutinin-neuraminidase (HN) open reading frames replaced with those from genotype XII strain NDV/peacock/Peru/2011 (PP2011) in a recombinant LaSota (rLS1) backbone. In rLS1-XII-2 virus, cytoplasmic tails of F and HN proteins were restored to those of rLS1. In vitro evaluation showed that rLS1-XII-2 and the parental rLS1 strains replicate at higher efficiencies than rLS1-XII-1. In the first vaccine/challenge experiment, SPF chickens vaccinated with rLS1-XII-1 virus showed only 71.3% protection, whereas, rLS1 and rLS1-XII-2 vaccinated chickens were fully protected. In a second experiment, both rLS1-XII-2 and the commercial vaccine strain LaSota induced 100% protection. However, rLS1-XII-2 virus significantly reduced viral shedding, both in the number of shedding birds and in quantity of shed virus. In conclusion, we have developed a vaccine candidate capable of fully protecting chickens against genotype XII challenges. Furthermore, we have shown the importance of cytoplasmic tails in virus replication and vaccine competence.

27 September 2016 in Avian Diseases
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ACAna Chumbe
Ana Chumbe
RLRay Izquierdo Lara
Ray Izquierdo Lara
Luis Tataje-LavandaLuis Tataje-Lavanda
Luis Tataje-Lavanda
RGRosa Gonzalez
Rosa Gonzalez
GCGiovana Cribillero
Giovana Cribillero
EIEliana Icochea
Eliana Icochea
SUMMARY Infections of poultry with virulent strains of avian paramyxovirus 1 (APMV-1), also known as Newcastle disease viruses (NDVs), cause Newcastle disease (ND). This highly contagious disease affects poultry and many other species of birds worldwide. In countries where the disease is prevalent, constant monitoring and characterization of isolates causing outbreaks are necessary. In this study, we report the results of pathogenicity testing and phylogenetic analyses of seven NDVs isolated from several regions of Peru between 2004 and 2015. Six viruses had intracerebral pathogenicity indices (ICPIs) of between 1.75 and 1.88, corresponding to a velogenic pathotype. The remaining virus had an ICPI of 0.00, corresponding to a lentogenic pathotype. These results were consistent with amino acid sequences at the fusion protein (F) cleavage site. All velogenic isolates had the polybasic amino acid sequence 112RRQKR↓F117 at the F cleavage site. Phylogenetic analyses of complete F gene sequences showed that all ... RESUMEN Tipificación patológica y caracterización filogenética de los virus de la enfermedad de Newcastle aislados en el Perú: Definición de dos subgenotipos nuevos dentro del genotipo XII. La infección en las aves comerciales con cepas virulentas de paramixovirus aviar 1 (APMV-1), también conocido como virus de la enfermedad de Newcastle (NDV), es la causa de la enfermedad de Newcastle (ND). Esta enfermedad altamente contagiosa afecta aves comerciales y muchas otras especies de aves en todo el mundo. En los países donde la enfermedad es prevalente, es necesario monitorear y caracterizar constantemente los aislamientos que causan brotes. En este estudio se presentan los resultados de las pruebas de patogenicidad y los análisis filogenéticos de siete aislamientos del virus de Newcastle de varias regiones del Perú entre los años 2004 y 2015. Seis virus presentaron índices de patogenicidad intracerebral (con las siglas en inglés: ICPI) de entre 1.75 y 1.88, que corresponden a un patotipo velogénico. El virus...

8 June 2013 in Bioinformation
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David Ruben RequenaDavid Ruben Requena
David Ruben Requena
ACAna Chumbe
Ana Chumbe
MTMichael Torres
Michael Torres
OAOfelia Alzamora
Ofelia Alzamora
MRManuel Ramirez
Manuel Ramirez
MFManolo Fernandez
Manolo Fernandez
Avibacterium paragallinarum, the causative agent of infectious coryza, is a highly contagious respiratory acute disease of poultry, which affects commercial chickens, laying hens and broilers worldwide. In this study, we performed the whole genome sequencing, assembly and annotation of a Peruvian isolate of A. paragallinarum. Genome was sequenced in a 454 GS FLX Titanium system. De novo assembly was performed and annotation was completed with GS De Novo Assembler 2.6 using the H. influenzae str. F3031 gene model. Manual curation of the genome was performed with Artemis. Putative function of genes was predicted with Blast2GO. Virulence factors were identified by comparison with the Virulence Factor Database. The genome obtained has a length of 2.47 Mb with 40.66% of GC content. Seventy five large contigs (>500 nt) were obtained, which comprised 1,204 predicted genes. All the contigs are available in Genbank [GenBank: PRJNA64665]. A total of 103 virulence factors, reported in the Virulence Factor Database, were found in A. paragallinarum. Forty four of them are present in 7 species of Haemophilus, which are related with pathogenesis, virulence and host immune system evasion. A tetracycline-resistance associated transposon (Tn10), was found in A. paragallinarum, possibly acting as a defense mechanism. The availability of A. paragallinarum genome represents an important source of information for the development of diagnostic tests, genotyping, and novel antigens for potential vaccines against infectious coryza. Identification of virulence factors contributes to better understanding the pathogenesis, and planning efforts for prevention and control of the disease.

10 November 2020 in Viruses
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NVNele Villabruna
Nele Villabruna
RLRay Izquierdo Lara
Ray Izquierdo Lara
JSJudit Szarvas
Judit Szarvas
MKMarion P.G. Koopmans
Marion P.G. Koopmans
Miranda de GraafMiranda de Graaf
Miranda de Graaf
Norovirus infections are a leading cause of acute gastroenteritis worldwide, affecting people of all ages. There are 10 norovirus genogroups (GI-GX) that infect humans and animals in a host-specific manner. New variants and genotypes frequently emerge, and their origin is not well understood. One hypothesis is that new human infections may be seeded from an animal reservoir, as human noroviruses have occasionally been detected in animal species. The majority of these sequences were identified as older GII.4 variants, but a variety of other GIIs and GIs have been detected as well. While these sequences share at least 94% nt similarity with human strains, most of them are >98% identical to human strains. The fact that these strains were detected in animals after they had been detected through human surveillance to be already circulating in humans suggests human-to-animal transmission.