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1.
Am J Primatol ; : e23654, 2024 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-38922738

RESUMO

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared a pandemic by the World Health Organization in March 2020. Since then, viral spread from humans to animals has occurred worldwide. Nonhuman primates (NHPs) have been found to be susceptible to reverse-zoonosis transmission of SARS-CoV-2, but initial research suggested that platyrrhine primates are less susceptible than catarrhine primates. Here we report the natural SARS-CoV-2 infection of a common woolly monkey (Lagothrix lagothricha) from a wildlife rehabilitation center in Ecuador. The course of the disease, the eventual death of the specimen, and the pathological findings are described. Our results show the susceptibility of a new platyrrhine species to SARS-CoV-2 and provide evidence for the first time of a COVID-19-associated death in a naturally infected NHP. The putative route of transmission from humans, and implications for captive NHPs management, are also discussed. Given that common woolly monkeys are at risk of extinction in Ecuador, further understanding of the potential threat of SARS-CoV-2 to their health should be a conservation priority. A One Health approach is the best way to protect NHPs from a new virus in the same way that we would protect the human population.

2.
J Infect Dis ; 226(7): 1200-1203, 2022 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-35176774

RESUMO

BACKGROUND: We have recently revealed that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Mu variant shows a pronounced resistance to antibodies elicited by natural SARS-CoV-2 infection and vaccination. METHODS: However, it remains unclear which mutations determine the resistance of SARS-CoV-2 Mu to antiviral sera. In addition, it is unclear how SARS-CoV-2 Mu infection induces antiviral immunity. RESULTS: In this study, we reveal that the 2 mutations in the SARS-CoV-2 Mu spike protein, YY144-145TSN and E484K, are responsible for the resistance to coronavirus disease 2019 convalescent sera during early 2020 and vaccine sera. CONCLUSIONS: It is notable that the convalescent sera of SARS-CoV-2 Mu-infected individuals are broadly antiviral against Mu as well as other SARS-CoV-2 variants of concern and interest.


Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Neutralizantes , Anticorpos Antivirais , Antivirais , COVID-19/terapia , Humanos , Imunização Passiva , Glicoproteína da Espícula de Coronavírus/genética , Soroterapia para COVID-19
3.
BMC Microbiol ; 21(1): 17, 2021 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413126

RESUMO

BACKGROUND: Leptospira are shed into the environment via urine of infected animals. Rivers are thought to be an important risk factor for transmission to humans, though much is unknown about the types of environment or characteristics that favor survival. To address this, we screened for Leptospira DNA in two rivers in rural Ecuador where Leptospirosis is endemic. RESULTS: We collected 112 longitudinal samples and recorded pH, temperature, river depth, precipitation, and dissolved oxygen. We also performed a series of three experiments designed to provide insight into Leptospira presence in the soil. In the first soil experiment, we characterized prevalence and co-occurrence of Leptospira with other bacterial taxa in the soil at dispersed sites along the rivers (n = 64). In the second soil experiment, we collected 24 river samples and 48 soil samples at three points along eight transects to compare the likelihood of finding Leptospira in the river and on the shore at different distances from the river. In a third experiment, we tested whether Leptospira presence is associated with soil moisture by collecting 25 soil samples from two different sites. In our river experiment, we found pathogenic Leptospira in only 4 (3.7%) of samples. In contrast, pathogenic Leptospira species were found in 22% of shore soil at dispersed sites, 16.7% of soil samples (compared to 4.2% of river samples) in the transects, and 40% of soil samples to test for associations with soil moisture. CONCLUSIONS: Our data are limited to two sites in a highly endemic area, but the scarcity of Leptospira DNA in the river is not consistent with the widespread contention of the importance of river water for leptospirosis transmission. While Leptospira may be shed directly into the river, onto the shores, or washed into the river from more remote sites, massive dilution and limited persistence in rivers may reduce the environmental load and therefore, the epidemiological significance of such sources. It is also possible that transmission may occur more frequently on shores where people are liable to be barefoot. Molecular studies that further explore the role of rivers and water bodies in the epidemiology of leptospirosis are needed.


Assuntos
Leptospira/classificação , Leptospirose/epidemiologia , Rios/microbiologia , Análise de Sequência de DNA/métodos , Solo/química , Animais , DNA Bacteriano , DNA Ribossômico/genética , Equador , Doenças Endêmicas , Humanos , Leptospira/genética , Leptospira/isolamento & purificação , Filogenia , Prevalência , RNA Ribossômico 16S/genética , População Rural , Microbiologia do Solo
4.
Appl Environ Microbiol ; 83(19)2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28754706

RESUMO

Exposure to soil or water contaminated with the urine of Leptospira-infected animals is the most common way in which humans contract leptospirosis. Entire populations can be at high risk of leptospirosis while working in inundated fields, when engaging in aquatic sports, or after periods of heavy rainfall. The risk of infection after contact with these environmental sources depends on the ability of Leptospira bacteria to survive, persist, and infect new hosts. Multiple variables such as soil and water pH, temperature, and even environmental microbial communities are likely to shape the environmental conditions needed by the pathogen to persist. Here we review what is known about the environmental phase of the infectious Leptospira transmission cycle and identify knowledge gaps that will serve as a guide for future research.


Assuntos
Leptospira/fisiologia , Leptospirose/transmissão , Leptospirose/veterinária , Animais , Humanos , Leptospira/genética , Leptospira/isolamento & purificação , Leptospirose/microbiologia , Microbiologia do Solo , Microbiologia da Água , Zoonoses/microbiologia , Zoonoses/transmissão
5.
Emerg Infect Dis ; 21(12): 2141-7, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26583534

RESUMO

Leptospira spp., which comprise 3 clusters (pathogenic, saprophytic, and intermediate) that vary in pathogenicity, infect >1 million persons worldwide each year. The disease burden of the intermediate leptospires is unclear. To increase knowledge of this cluster, we used new molecular approaches to characterize Leptospira spp. in 464 samples from febrile patients in rural, semiurban, and urban communities in Ecuador; in 20 samples from nonfebrile persons in the rural community; and in 206 samples from animals in the semiurban community. We observed a higher percentage of leptospiral DNA-positive samples from febrile persons in rural (64%) versus urban (21%) and semiurban (25%) communities; no leptospires were detected in nonfebrile persons. The percentage of intermediate cluster strains in humans (96%) was higher than that of pathogenic cluster strains (4%); strains in animal samples belonged to intermediate (49%) and pathogenic (51%) clusters. Intermediate cluster strains may be causing a substantial amount of fever in coastal Ecuador.


Assuntos
Surtos de Doenças , Febre de Causa Desconhecida/diagnóstico , Leptospira/patogenicidade , Leptospirose/diagnóstico , Animais , Equador/epidemiologia , Febre de Causa Desconhecida/epidemiologia , Febre de Causa Desconhecida/virologia , Humanos , Leptospira/genética , Leptospira/virologia , Leptospirose/epidemiologia , Prevalência , População Rural , Análise de Sequência de DNA/métodos , População Urbana
6.
RNA ; 19(12): 1711-25, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24129493

RESUMO

MicroRNAs (miRNAs) have been widely studied in order to elucidate their biological functions. MicroRNA microarrays or miRNA overexpression libraries generated by synthesis and cloning of individual miRNAs have been used to study their different roles. In this work, we have developed a novel methodology to express mature miRNAs and other small RNAs from a double convergent RNA polymerase III promoter. We show that the generated miRNAs function similarly to those processed from primary transcripts or pri-miRNAs. This system allowed us to produce a lentiviral library expressing the whole population of small RNAs present in a metastatic cell line. A functional screening using this library led to the identification of hsa-miR-30b and hsa-miR-30c as negative regulators of cell death induced by loss of attachment (anoikis). Importantly, we demonstrated that the acquisition of anoikis resistance via these miRNAs is achieved through down-regulation of caspase 3 expression. Moreover, overexpression of these miRNAs resulted in a decrease of other types of caspase 3-dependent cell death and enhanced the survival of MCF10A acinar cells in morphogenesis assays, suggesting a putative role as oncomirs. In summary, this novel methodology provides a powerful and effective way for identifying novel small RNAs involved in a particular biological process.


Assuntos
Anoikis/genética , Caspase 3/genética , MicroRNAs/genética , Regiões 3' não Traduzidas , Sequência de Bases , Sítios de Ligação , Caspase 3/metabolismo , Técnicas de Cultura de Células , Forma Celular , Repressão Enzimática , Feminino , Expressão Gênica , Biblioteca Gênica , Células HCT116 , Células HEK293 , Humanos , Glândulas Mamárias Humanas/citologia , MicroRNAs/metabolismo , Morfogênese , Interferência de RNA
7.
Plant Cell ; 24(3): 1127-42, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22438021

RESUMO

Intracellular NHX proteins are Na(+),K(+)/H(+) antiporters involved in K(+) homeostasis, endosomal pH regulation, and salt tolerance. Proteins NHX1 and NHX2 are the two major tonoplast-localized NHX isoforms. Here, we show that NHX1 and NHX2 have similar expression patterns and identical biochemical activity, and together they account for a significant amount of the Na(+),K(+)/H(+) antiport activity in tonoplast vesicles. Reverse genetics showed functional redundancy of NHX1 and NHX2 genes. Growth of the double mutant nhx1 nhx2 was severely impaired, and plants were extremely sensitive to external K(+). By contrast, nhx1 nhx2 mutants showed similar sensitivity to salinity stress and even greater rates of Na(+) sequestration than the wild type. Double mutants had reduced ability to create the vacuolar K(+) pool, which in turn provoked greater K(+) retention in the cytosol, impaired osmoregulation, and compromised turgor generation for cell expansion. Genes NHX1 and NHX2 were highly expressed in guard cells, and stomatal function was defective in mutant plants, further compromising their ability to regulate water relations. Together, these results show that tonoplast-localized NHX proteins are essential for active K(+) uptake at the tonoplast, for turgor regulation, and for stomatal function.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de Transporte de Cátions/metabolismo , Estômatos de Plantas/fisiologia , Potássio/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , Vacúolos/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Transporte de Cátions/genética , DNA Bacteriano/genética , Regulação da Expressão Gênica de Plantas , Teste de Complementação Genética , Homeostase , Mutagênese Insercional , Transpiração Vegetal , Isoformas de Proteínas , Sódio/metabolismo , Trocadores de Sódio-Hidrogênio/genética
8.
PLoS Negl Trop Dis ; 18(4): e0011671, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38568912

RESUMO

BACKGROUND: Leptospirosis is the world's most common zoonotic disease. Mitigation and control rely on pathogen identification and understanding the roles of potential reservoirs in cycling and transmission. Underreporting and misdiagnosis obscure the magnitude of the problem and confound efforts to understand key epidemiological components. Difficulties in culturing hamper the use of serological diagnostics and delay the development of DNA detection methods. As a result, especially in complex ecosystems, we know very little about the importance of different mammalian host species in cycling and transmission to humans. METHODOLOGY/PRINCIPAL FINDINGS: We sampled dogs from five indigenous Kichwa communities living in the Yasuní National Park in the Ecuadorian Amazon basin. Blood and urine samples from domestic dogs were collected to assess the exposure of these animals to Leptospira and to identify the circulating species. Microscopic Agglutination Tests with a panel of 22 different serovars showed anti-leptospira antibodies in 36 sampled dogs (75%), and 7 serogroups were detected. Two DNA-based detection assays revealed pathogenic Leptospira DNA in 18 of 19 dog urine samples (94.7%). Amplicon sequencing and phylogenetic analysis of 16S rRNA and SecY genes from 15 urine samples revealed genetic diversity within two of three different Leptospira species: noguchii (n = 7), santarosai (n = 7), and interrogans (n = 1). CONCLUSIONS/SIGNIFICANCE: The high prevalence of antibodies and Leptospira DNA provides strong evidence for high rates of past and current infections. Such high prevalence has not been previously reported for dogs. These dogs live in the peridomestic environment in close contact with humans, yet they are free-ranging animals that interact with wildlife. This complex web of interactions may explain the diverse types of pathogenic Leptospira observed in this study. Our results suggest that domestic dogs are likely to play an important role in the cycling and transmission of Leptospira. Future studies in areas with complex ecoepidemiology will enable better parsing of the significance of genotypic, environmental, and host characteristics.


Assuntos
Leptospira , Leptospirose , Animais , Cães , Humanos , Ecossistema , Filogenia , RNA Ribossômico 16S/genética , Leptospirose/epidemiologia , Leptospirose/veterinária , Animais Selvagens , DNA , Mamíferos
9.
Microbiol Spectr ; 12(4): e0274123, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38364080

RESUMO

Human populations can be affected in unpredictable ways by the emergence and spread of zoonotic diseases. The COVID-19 (coronavirus disease of 2019) pandemic was a reminder of how devastating these events can be if left unchecked. However, once they have spread globally, the impact of these diseases when entering non-exposed wildlife populations is unknown. The current study reports the infection of brown-headed spider monkeys (Ateles fusciceps) at a wildlife rescue center in Ecuador. Four monkeys were hospitalized, and all tested positive for SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) by RT-qPCR (Quantitative Reverse Transcription PCR). Fecal samples (n = 12) from monkeys at the rescue center also tested positive; three zookeepers responsible for feeding and deworming the monkeys also tested positive, suggesting human-animal transmission. Whole genome sequencing identified most samples' omicron clade 22B BA.5 lineage. These findings highlight the threat posed by an emerging zoonotic disease in wildlife species and the importance of preventing spillover and spillback events during epidemic or pandemic events.IMPORTANCEAlthough COVID-19 (coronavirus disease of 2019) has been primarily contained in humans through widespread vaccination, the impact and incidence of SARS-CoV-2 (Severe acute respiratory syndrome coronavirus) and its transmission and epidemiology in wildlife may need to be addressed. In some natural environments, the proximity of animals to humans is difficult to control, creating perfect scenarios where susceptible wildlife can acquire the virus from humans. In these places, it is essential to understand how transmission can occur and to develop protocols to prevent infection. This study reports the infection of brown-headed spider monkeys with SARS-CoV-2, a red-listed monkey species, at a wildlife recovery center in Ecuador. This study reports the infection of brown-headed spider monkeys with SARS-CoV-2, indicating the potential for transmission between humans and wildlife primates and the importance of preventing such events in the future.


Assuntos
Atelinae , COVID-19 , Animais , Humanos , Animais Selvagens , COVID-19/epidemiologia , COVID-19/veterinária , Equador/epidemiologia , SARS-CoV-2/genética , Zoonoses/epidemiologia , América do Sul , Pandemias
10.
bioRxiv ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38915728

RESUMO

Leptospirosis (caused by pathogenic bacteria in the genus Leptospira ) is prevalent worldwide but more common in tropical and subtropical regions. Transmission can occur following direct exposure to infected urine from reservoir hosts, such as rats, or a urine-contaminated environment, which then can serve as an infection source for additional rats and other mammals, including humans. The brown rat, Rattus norvegicus , is an important reservoir of leptospirosis in urban settings. We investigated leptospirosis among brown rats in Boston, Massachusetts and hypothesized that rat dispersal in this urban setting influences the movement, persistence, and diversity of Leptospira . We analyzed DNA from 328 rat kidney samples collected from 17 sites in Boston over a seven-year period (2016-2022); 59 rats representing 12 of 17 sites were positive for Leptospira . We used 21 neutral microsatellite loci to genotype 311 rats and utilized the resulting data to investigate genetic connectivity among sampling sites. We generated whole genome sequences for 28 Leptospira isolates obtained from frozen and fresh tissue from some of the 59 Leptospira -positive rat kidneys. When isolates were not obtained, we attempted Leptospira genomic DNA capture and enrichment, which yielded 14 additional Leptospira genomes from rats. We also generated an enriched Leptospira genome from a 2018 human case in Boston. We found evidence of high genetic structure and limited dispersal among rat populations that is likely influenced by major roads and/or other unknown dispersal barriers, resulting in distinct rat population groups within the city; at certain sites these groups persisted for multiple years. We identified multiple distinct phylogenetic clades of L. interrogans among rats, with specific clades tightly linked to distinct rat populations. This pattern suggests L. interrogans persists in local rat populations and movement of leptospirosis in this urban rat community is driven by rat dispersal. Finally, our genomic analyses of the 2018 human leptospirosis case in Boston suggests a link to rats as the source. These findings will be useful for guiding rat control and human leptospirosis mitigation efforts in this and other urban settings.

11.
Vet World ; 16(10): 2110-2119, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38023277

RESUMO

Background and Aim: Leptospirosis is considered a neglected tropical zoonosis in low-income countries due to surveillance system limitations and non-specificity of symptoms. Humans become infected through direct contact with carrier animals or indirectly through Leptospira-contaminated environments. Conventionally, equines have been considered an uncommon source of leptospirosis, but recent publications in Latin America suggest that their role in the maintenance and dispersion of the bacteria could be more relevant than expected, as horses are susceptible to a wide variety of zoonotic Leptospira spp. from domestic and wild animals with which they share the environment. A systematic review of the published literature was conducted to compile the available information on Leptospira spp. in Ecuador, with a special focus on equine leptospirosis, to better understand the epidemiology of the bacterium and identify possible knowledge gaps. Materials and Methods: A systematic review of the published literature was conducted in PubMed, SciELO and Web of Science databases to compile the available information on Leptospira spp. in Ecuador, with a special focus on equine leptospirosis, to better understand the epidemiology of the bacterium. We used a combination of the terms (Leptospira OR Leptospirosis) AND Ecuador, without restrictions on language or publication date. Results: Our literature review reveals that published scientific information is very scarce. Eighteen full-text original scientific articles related to Leptospira or leptospirosis cases in Ecuador were included in the systematic review. Most of the studies reported data obtained from one of the four regions (Coast), and specifically from only one of the 24 Provinces of Ecuador (Manabí), which evidence a large information bias at the geographical level. Furthermore, only the studies focused on humans included clinical signs of leptospirosis and there is only one study that analyzes the presence of Leptospira spp. in water or soil as a risk factor for pathogen transmission. Finally, only one study investigated Leptospira in horses. Conclusion: Since sentinel species can provide useful data on infectious diseases when epidemiologic al information is lacking, and horses could be considered excellent sentinel species to reveal circulating serovars, we propose developing a nationwide surveillance system using horses. This cost-effective epidemiological survey method provides a baseline for implementing specific prevention and control programs in Ecuador and neighboring developing countries.

12.
Animals (Basel) ; 13(23)2023 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-38067007

RESUMO

BACKGROUND: The emblematic Galapagos sea lion (GSL-Zalophus wollebaeki) has faced an important population decline over the last four decades. There are multiple environmental and biological factors that might be implied in this decrease. Recently, evidence of various zoonotic infectious diseases that can be potential threats has been reported. Considering that in some islands of the archipelago the risk of transmission of infectious diseases may be promoted by the increasing population of domestic dogs, epidemiological vigilance and search of new pathogens are essential. The canine distemper virus (CDV), one of the viral pathogens that generate the most concern for the agencies responsible for the management and conservation of the Galapagos pinnipeds, was detected in the GSL in 2010. However, there is scarce information about its impact on GSL health and about its epidemiology. METHODS: In this study, 110 GSL serum samples were collected during the summer of 2016 and 2017. All samples were exposed to VERO dog SLAM cells expressing the canine SLAM receptor. RESULTS: Our results showed a significative increase (p = 0.04) in the frequency of neutralizing antibodies to CDV in the 2017 (53.1%) samples compared to the 2016 samples (19.6%). CONCLUSIONS: Our work confirmed the continuous and increasing circulation of the CDV in the GSL and highlights the importance of monitoring emerging diseases that can be transmitted from domestic to wildlife species. Vigilance of CDV is essential to understand the role of this virus in GSL mortality and to take informed decisions for wildlife conservation.

13.
bioRxiv ; 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37786682

RESUMO

Background: Leptospirosis is the world's most common zoonotic disease. Mitigation and control rely on pathogen identification and understanding the roles of potential reservoirs in cycling and transmission. Underreporting and misdiagnosis obscure the magnitude of the problem and confound efforts to understand key epidemiological components. Difficulties in culturing hamper the use of serological diagnostics and delay the development of DNA detection methods. As a result, especially in complex ecosystems, we know very little about the importance of different mammalian host species in cycling and transmission to humans. Methodology/Principal Findings: We sampled five indigenous Kichwa communities living in the Yasuní National Park in the Ecuadorian Amazon basin. Blood and urine samples from domestic dogs were collected to assess the exposure of these animals to Leptospira, and to identify the circulating species. Microscopic Agglutination Tests with a panel of 22 different serovars showed anti-leptospira antibodies in 36 sampled dogs (75%), and 10 serotypes were detected. Two DNA-based detection assays revealed pathogenic Leptospira DNA in 18 of 19 dog urine samples (94.7%). Amplicon sequencing and phylogenetic analysis of 16s rDNA and SecY genes from 15 urine samples revealed genetic diversity within two of three different Leptospira species: noguchii (n=7), santarosai (n=7), and interrogans (n=1). Conclusions/Significance: The high prevalence of antibodies and Leptospira DNA provides strong evidence for high rates of past and current infections. Such high prevalence has not been previously reported for dogs. These dogs live in the peridomestic environment in close contact with humans, yet they are free-ranging animals that interact with wildlife. This complex web of interactions may explain the diverse types of pathogenic Leptospira observed in this study. Our results suggest that domestic dogs are likely to play an important role in the cycling and transmission of Leptospira. Future studies in areas with complex ecoepidemiology will enable better parsing of the significance of genotypic, environmental, and host characteristics.

14.
PLoS One ; 17(9): e0274362, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36129918

RESUMO

BACKGROUND: Leptospirosis causes significant economic losses and is an occupational risk in the swine industry, especially in developing tropical regions where social and geoclimatic conditions are favorable for the transmission of this disease. Although vaccination can reduce infection risk, efficacy is diminished if local genetic and antigenic variants of the pathogen are not accounted for in the vaccine. Identifying and characterizing strains hosts, and potential mechanisms of transmission is therefore critical for public health mitigation practices. METHODOLOGY/PRINCIPAL FINDINGS: Our study was conducted on a rural breeding farm in Ecuador, where we used a PCR assay that targets lipL32 to detect Leptospira spp. and targeted gene sequencing to identify Leptospira santarosai in the kidneys, testicles, and ejaculate of a vaccinated boar. MAT results showed low titers against serovars found in the vaccine, but the MAT panel did not include serovars of L. santarosai. The boar showed no symptoms of leptospirosis but did show blood in the semen. However, no postmortem histopathological lesions were observed tissue samples. Vaccinated sows that were artificially inseminated with the semen from this boar had reproductive problems, suggesting that transmission had occurred. This is the first documented case of Leptospira santarosai in the reproductive tract of a boar. CONCLUSIONS/SIGNIFICANCE: As L. santarosai is pathogenic in other livestock species and humans, our finding highlights the need to evaluate the prevalence and epidemiological significance of this pathogen in livestock and consider the possibility of venereal transmission. In addition, further studies are needed to identify and characterize local serovars that may impact diagnosis and vaccination programs to better control leptospirosis in livestock and spillover into the human population.


Assuntos
Leptospira , Leptospirose , Animais , Feminino , Leptospira/genética , Leptospirose/epidemiologia , Leptospirose/prevenção & controle , Leptospirose/veterinária , Gado , Masculino , Saúde Pública , Sorogrupo , Suínos
15.
Front Cell Infect Microbiol ; 12: 951383, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36164552

RESUMO

SARS-CoV-2 reinfection is defined as a new infection with a different virus variant in an individual who has already recovered from a previous episode of COVID-19. The first case of reinfection in the world was described in August 2020, since then, reinfections have increased over time and their incidence has fluctuated with specific SARS-CoV-2 variant waves. Initially, reinfections were estimated to represent less than 1% of total COVID-19 infections. With the advent of the Omicron variant, reinfections became more frequent, representing up to 10% of cases (based on data from developed countries). The frequency of reinfections in Latin America has been scarcely reported. The current study shows that in Ecuador, the frequency of reinfections has increased 10-fold following the introduction of Omicron, after 22 months of surveillance in a single center of COVID-19 diagnostics. Suspected reinfections were identified retrospectively from a database of RT-qPCR-positive patients. Cases were confirmed by sequencing viral genomes from the first and second infections using the ONT MinION platform. Monthly surveillance showed that the main incidence peaks of reinfections were reached within four to five months, coinciding with the increase of COVID-19 cases in the country, suggesting that the emergence of reinfections is related to higher exposure to the virus during outbreaks. This study performed the longest monitoring of SARS-CoV-2 reinfections, showing an occurrence at regular intervals of 4-5 months and confirming a greater propensity of Omicron to cause reinfections.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , COVID-19/epidemiologia , Equador/epidemiologia , Humanos , Reinfecção , Estudos Retrospectivos , SARS-CoV-2/genética
16.
Plant J ; 61(3): 495-506, 2010 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-19912566

RESUMO

NHX-type antiporters in the tonoplast have been reported to increase the salt tolerance of various plants species, and are thought to mediate the compartmentation of Na(+) in vacuoles. However, all isoforms characterized so far catalyze both Na(+)/H(+) and K(+)/H(+) exchange. Here, we show that AtNHX1 has a critical involvement in the subcellular partitioning of K(+), which in turn affects plant K(+) nutrition and Na(+) tolerance. Transgenic tomato plants overexpressing AtNHX1 had larger K(+) vacuolar pools in all growth conditions tested, but no consistent enhancement of Na(+) accumulation was observed under salt stress. Plants overexpressing AtNHX1 have a greater capacity to retain intracellular K(+) and to withstand salt-shock. Under K(+)-limiting conditions, greater K(+) compartmentation in the vacuole occurred at the expense of the cytosolic K(+) pool, which was lower in transgenic plants. This caused the early activation of the high-affinity K(+) uptake system, enhanced K(+) uptake by roots, and increased the K(+) content in plant tissues and the xylem sap of transformed plants. Our results strongly suggest that NHX proteins are likely candidates for the H(+)-linked K(+) transport that is thought to facilitate active K(+) uptake at the tonoplast, and the partitioning of K(+) between vacuole and cytosol.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Potássio/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , Solanum lycopersicum/metabolismo , Vacúolos/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Transporte de Cátions/genética , Regulação da Expressão Gênica de Plantas , Solanum lycopersicum/genética , Plantas Geneticamente Modificadas , Trocadores de Sódio-Hidrogênio/genética
17.
Curr Microbiol ; 62(6): 1802-6, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21479795

RESUMO

Leptospires can persist for months in nutrient-poor aqueous environments prior to transmission to a mammalian host. Interactions with environmental bacteria and biofilm formation are possible mechanisms of persistence of leptospires in the environment. Bacteria isolated from rivers in the Ecuadorian rainforest were tested for their ability to support leptospiral viability. We found that co-culture with Sphingomonas spp., but not Flavobacterium spp. or Delftia spp., enabled survival of L. biflexa and L. meyeri for up to a year in distilled water. We also found that L. interrogans biofilms formed in distilled water contained viable organisms that rapidly dispersed into the planktonic phase in the presence of nutrients in serum or EMJH medium. These data inform our understanding of leptospiral survival strategies that enable long-term persistence in nutrient-poor conditions yet allow rapid mobilization when nutrients become available.


Assuntos
Fenômenos Fisiológicos Bacterianos , Leptospira/fisiologia , Rios/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biofilmes , Técnicas de Cocultura , Leptospira/genética , Viabilidade Microbiana , Dados de Sequência Molecular
18.
Vet World ; 14(7): 1935-1945, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34475720

RESUMO

BACKGROUND AND AIM: Ecuador is a hugely diverse country, but information on infectious diseases in local wild animals is scarce. The aim of this study was to screen the presence of blood parasites in free-ranging wild animals admitted to the Wildlife Hospital at Universidad San Francisco de Quito, from April 2012 to January 2019. MATERIALS AND METHODS: We identified blood parasites by microscopic observation of blood smears from free-ranging wildlife species that attended the Wildlife Hospital of Universidad San Francisco de Quito (Ecuador) from April 2012 to January 2019. RESULTS: The microscopic evaluations of animals as potential reservoirs for vector-borne zoonotic blood parasites revealed the presence of Anaplasma spp., Babesia spp., Ehrlichia spp., Hepatozoon spp., microfilaria, Mycoplasma spp., and Trypanosoma spp. in previously unreported wildlife species. In addition, we performed a systematic review to understand the current knowledge gaps in the context of these findings. CONCLUSION: Our data contribute to the knowledge of blood parasites in wildlife from Ecuador. Furthermore, the potential transmission of these parasites to humans and domestic animals, current anthropogenic environmental changes in the region, and the lack of information on this suggest the importance of our results and warrant further investigations on infectious diseases in animals and humans and their relationship with environmental health as key domains of the One Health concept.

19.
IDCases ; 25: e01187, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34136351

RESUMO

BACKGROUND: SARS-CoV-2 uses the human cell receptor angiotensin-converting enzyme (ACE2). ACE2 is widely present in the cardiovascular system including the myocardium and the conduction system. COVID-19 patients that present severe symptoms have been reported to have complications involving myocardial injuries caused by the virus. Here we report the detection of SARS-CoV-2 by whole genome sequencing in the endocardium of a patient with severe bradycardia. CASE PRESENTATION: We report a case of a 34-year-old male patient with COVID-19 tested by PCR, he started with gastrointestinal symptoms, however, he quickly deteriorated his hemodynamic state by means of myocarditis and bradycardia. After performing an endocardium biopsy, it was possible to identify the presence of SARS-CoV-2 in the heart tissue and to sequence its whole genome using the ARTIC-Network protocol and a modified tissue RNA extraction method. The patient's outcome was improved after a permanent pacemaker was implanted. CONCLUSIONS: It was possible to identify a SARS-CoV-2 clade 20A in the endocardium of the reported patient.

20.
medRxiv ; 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33791722

RESUMO

SARS-CoV-2, the etiological agent of COVID-19, was first described in Wuhan, China in December 2019 and has now spread globally. Ecuador was the second country in South America to confirm cases and Guayaquil was one of the first cities in the world to experience high mortality due to COVID-19. The aim of this study was to describe the lineages circulating throughout the country and to compare the mutations in local variants, to the reference strain. In this work we used the MinION platform (Oxford Nanopore Technologies) to sequence the whole SARS-CoV-2 genomes of 119 patients from all provinces of Ecuador, using the ARTIC network protocols. Our data from lineage assignment of the one hundred and nineteen whole genomes revealed twenty different lineages. All genomes presented differences in the S gene compared to the Wuhan reference strain, being the D614G amino acid replacement the most common change. The B.1.1.119 lineage was the most frequent and was found in several locations in the Coast and Andean region. Three sequences were assigned to the new B.1.1.7 lineage. Our work is an important contribution to the understanding of the epidemiology of SARS-CoV-2 in Ecuador and South America.

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