Nanotechnology-based pesticides: Environmental fate and ecotoxicity.

The imminent increase in global food demand inevitably leads to an increase in agricultural practices, with an emphasis on pesticide applications. Nanotechnology-based pesticides, or nanopesticides, have gained importance as they are more efficient and, in some cases, less toxic than their conventional counterparts. However, concerns about these novel products have arisen as evidence about their (eco)safety is controversial. This review aims to: (1) introduce the currently applied nanotechnology-based pesticides and their mechanisms of toxic action; (2) describe their fate when released into the environment, with an emphasis on aquatic environments; (3) summarize available research on ecotoxicological studies in freshwater non-target organisms through a bibliometric analysis; and (4) identify gaps in knowledge from an ecotoxicological perspective. Our results show that the environmental fate of nanopesticides is poorly studied and depends on both intrinsic and external factors. There is also a need for comparative research into their ecotoxicity between conventional pesticide formulations and their nano-based counterparts. Among the few available studies, most considered fish species as test organisms, compared to algae and invertebrates. Overall, these new materials generate toxic effects on non-target organisms and threaten the integrity of the environment. Therefore, deepening the understanding of their ecotoxicity is crucial.

In vitro Susceptibility of Human Cell Lines Infection by Bovine Leukemia Virus.

Evidence of the presence of bovine leukemia virus (BLV) in human beings and its association with breast cancer has been published in the literature, proposing it as a zoonotic infection. However, not enough evidence exists about transmission pathways nor biological mechanisms in human beings. This study was aimed at gathering experimental evidence about susceptibility of human cell lines to BLV infection. Malignant and non-malignant human cell lines were co-cultured with BLV-infected FLK cells using a cell-to-cell model of infection. Infected human cell lines were harvested and cultured for 3 to 6 months to determine stability of infection. BLV detection was performed through liquid-phase PCR and visualized through in situ PCR. Seven out of nine cell lines were susceptible to BLV infection as determined by at least one positive liquid-phase PCR result in the 3-month culture period. iSLK and MCF7 cell lines were able to produce a stable infection throughout the 3-month period, with both cytoplasmic and/or nuclear BLV-DNA visualized by IS-PCR. Our results support experimental evidence of BLV infection in humans by demonstrating the susceptibility of human cells to BLV infection, supporting the hypothesis of a natural transmission from cattle to humans.

Risk factor for breast cancer development under exposure to bovine leukemia virus in Colombian women: A case-control study.

Viruses have been implicated in cancer development in both humans and animals. The role of viruses in cancer is typically to initiate cellular transformation through cellular DNA damage, although specific mechanisms remain unknown. Silent and long-term viral infections need to be present, in order to initiate cancer disease. In efforts to establish a causative role of viruses, first is needed to demonstrate the strength and consistency of associations in different populations. The aim of this study was to determine the association of bovine leukemia virus (BLV), a causative agent of leukemia in cattle, with breast cancer and its biomarkers used as prognosis of the severity of the disease (Ki67, HER2, hormonal receptors) in Colombian women. An unmatched, observational case-control study was conducted among women undergoing breast surgery between 2016-2018. Malignant samples (n = 75) were considered as cases and benign samples (n = 83) as controls. Nested-liquid PCR, in-situ PCR and immunohistochemistry were used for viral detection in blood and breast tissues. For the risk assessment, only BLV positive samples from breast tissues were included in the analysis. BLV was higher in cases group (61.3%) compared with controls (48.2%), with a statistically significant association between the virus and breast cancer in the unconditional logistic regression (adjusted-OR = 2.450,95%CI:1.088-5.517, p = 0.031). In this study, BLV was found in both blood and breast tissues of participants and an association between breast cancer and the virus was confirmed in Colombia, as an intermediate risk factor.

Co-Circulation of Bovine Leukemia Virus Haplotypes among Humans, Animals, and Food Products: New Insights of Its Zoonotic Potential.

Bovine leukemia virus (BLV) is the causative agent of leukemia/lymphoma in cattle. It has been found in humans and cattle-derived food products. In humans, it is described as a potential risk factor for breast cancer development. However, the transmission path remains unclear. Here, a molecular epidemiology analysis was performed to identify signatures of genetic flux of BLV among humans, animals, and food products. Sequences obtained from these sources in Colombia were used (n = 183) and compared with reference sequences available in GenBank. Phylogenetic reconstruction was performed in IQ-TREE software with the maximum likelihood algorithm. Haplotype (hap) distribution among the population was carried out with a median-joining model in Network5.0. Recombination events were inferred using SplitsTree4 software. In the phylogenetic analysis, no specific branches were identified for the Colombian sequences or for the different sources. A total of 31 haps were found, with Hap 1, 4, 5 and 7 being shared among the three sources of the study. Reticulation events among the different sources were also detected during the recombination analysis. These results show new insights about the zoonotic potential of BLV, showing evidence of genetic flux between cattle and humans. Prevention and control strategies should be considered to avoid viral dissemination as part of the One Health program policies.

Ecotoxicity of silica nanoparticles in aquatic organisms: An updated review.

This review aims to (i) provide a current overview of the main characteristics of SiNP (physical and chemical properties, applications, and emissions), (ii) evaluate the scientific production up to date concerning SiNP, with focus on their toxic effects, through a bibliometric analysis, (iii) describe the main toxic mechanisms of SiNP, (iv) assess the current knowledge about ecotoxicity of SiNP on aquatic organisms (marine and freshwater), and (v) identify the main gaps in the knowledge of SiNP toxicity from an environmentally point of view. The scientific production of SiNP concerning their chemical and physical characteristics has increased exponentially. However, little information is available regarding their ecotoxicity. Particle functionalization is a key factor that reduces SiNP toxicity. Most of the studies employed standard species as test organisms, being the local/native ones poorly represented. Further studies employing long-term exposures and environmentally relevant concentrations are needed to deepen the knowledge about this emergent pollutant.

Water and sediment quality assessment in the Colastiné-Corralito stream system (Santa Fe, Argentina): impact of industry and agriculture on aquatic ecosystems.

The present study focuses on the evaluation of metal (chromium, copper, and lead), arsenic, and pesticide (atrazine and endosulfan) contamination in freshwater streams of one of the most important agricultural and industrial areas of central-eastern Argentina, which has not been reported earlier. The environmental fate of inorganic microcontaminants and pesticides was assessed. Samples were collected monthly for a year. Pesticide concentrations were measured in water; metal and arsenic concentrations were measured in water and sediments, and physicochemical variables were analyzed. In most cases, metals and arsenic in water exceeded the established guideline levels for the protection of aquatic biota: 98 and 56.25% of the samples showed higher levels of Cr and Pb, while 81.25 and 85% of the samples presented higher values for Cu and As, respectively. Cr, Pb, Cu, and As exceeded 181.5 times, 41.6 times, 57.5 times, and 12.9 times, respectively, the guideline level values. In sediment samples, permitted levels were also surpassed by 40% for Pb, 15% for As, 4% for Cu, and 2% for Cr. Geoaccumulation Index (Igeo) demonstrated that most of the sediment samples were highly polluted by Cr and Cu and very seriously polluted by Pb, which indicates progressive deterioration of the sediment quality. Atrazine never exceeded them, but 27% of the 48 water samples contained total endosulfan that surpassed the guidelines. The findings of this study suggest risk to the freshwater biota over prolong periods and possible risk to humans if such type of contaminated water is employed for recreation or human use. Improper disposal of industrial effluents and agricultural runoffs need to be controlled, and proper treatment should be done before disposal to avoid further deterioration of the aquifers of this area.

Phylogenetic analysis of complete genome sequences of hepatitis B virus from an Afro-Colombian community: presence of HBV F3/A1 recombinant strain.

BACKGROUND: Hepatitis B virus (HBV) infection is one of the most prevalent viral infections in humans and represents a serious public health problem. In Colombia, our group reported recently the presence of subgenotypes F3, A2 and genotype G in Bogotá. The aim of this study was to characterize the HBV genotypes circulating in Quibdó, the largest Afro-descendant community in Colombia. Sixty HBsAg-positive samples were studied. A fragment of 1306 bp (S/POL) was amplified by nested PCR. Positive samples to S/POL fragment were submitted to PCR amplification of the HBV complete genome. FINDINGS: The distribution of HBV genotypes was: A1 (52.17%), E (39.13%), D3 (4.3%) and F3/A1 (4.3%). An HBV recombinant strain subgenotype F3/A1 was found for the first time. CONCLUSIONS: This study is the first analysis of complete HBV genome sequences from Afro-Colombian population. It was found an important presence of HBV/A1 and HBV/E genotypes. A new recombinant strain of HBV genotype F3/A1 was reported in this population. This fact may be correlated with the introduction of these genotypes in the times of slavery.

Frequency and genotypic distribution of GB virus C (GBV-C) among Colombian population with Hepatitis B (HBV) or Hepatitis C (HCV) infection.

BACKGROUND: GB virus C (GBV-C) is an enveloped positive-sense ssRNA virus belonging to the Flaviviridae family. Studies on the genetic variability of the GBV-C reveals the existence of six genotypes: genotype 1 predominates in West Africa, genotype 2 in Europe and America, genotype 3 in Asia, genotype 4 in Southwest Asia, genotype 5 in South Africa and genotype 6 in Indonesia. The aim of this study was to determine the frequency and genotypic distribution of GBV-C in the Colombian population. METHODS: Two groups were analyzed: i) 408 Colombian blood donors infected with HCV (n = 250) and HBV (n = 158) from Bogotá and ii) 99 indigenous people with HBV infection from Leticia, Amazonas. A fragment of 344 bp from the 5' untranslated region (5' UTR) was amplified by nested RT PCR. Viral sequences were genotyped by phylogenetic analysis using reference sequences from each genotype obtained from GenBank (n = 160). Bayesian phylogenetic analyses were conducted using Markov chain Monte Carlo (MCMC) approach to obtain the MCC tree using BEAST v.1.5.3. RESULTS: Among blood donors, from 158 HBsAg positive samples, eight 5.06% (n = 8) were positive for GBV-C and from 250 anti-HCV positive samples, 3.2%(n = 8) were positive for GBV-C. Also, 7.7% (n = 7) GBV-C positive samples were found among indigenous people from Leticia. A phylogenetic analysis revealed the presence of the following GBV-C genotypes among blood donors: 2a (41.6%), 1 (33.3%), 3 (16.6%) and 2b (8.3%). All genotype 1 sequences were found in co-infection with HBV and 4/5 sequences genotype 2a were found in co-infection with HCV. All sequences from indigenous people from Leticia were classified as genotype 3. The presence of GBV-C infection was not correlated with the sex (p = 0.43), age (p = 0.38) or origin (p = 0.17). CONCLUSIONS: It was found a high frequency of GBV-C genotype 1 and 2 in blood donors. The presence of genotype 3 in indigenous population was previously reported from Santa Marta region in Colombia and in native people from Venezuela and Bolivia. This fact may be correlated to the ancient movements of Asian people to South America a long time ago.

Evolution of naturally occurring 5'non-coding region variants of Hepatitis C virus in human populations of the South American region.

BACKGROUND: Hepatitis C virus (HCV) has been the subject of intense research and clinical investigation as its major role in human disease has emerged. Previous and recent studies have suggested a diversification of type 1 HCV in the South American region. The degree of genetic variation among HCV strains circulating in Bolivia and Colombia is currently unknown. In order to get insight into these matters, we performed a phylogenetic analysis of HCV 5' non-coding region (5'NCR) sequences from strains isolated in Bolivia, Colombia and Uruguay, as well as available comparable sequences of HCV strains isolated in South America. METHODS: Phylogenetic tree analysis was performed using the neighbor-joining method under a matrix of genetic distances established under the Kimura-two parameter model. Signature pattern analysis, which identifies particular sites in nucleic acid alignments of variable sequences that are distinctly representative relative to a background set, was performed using the method of Korber & Myers, as implemented in the VESPA program. Prediction of RNA secondary structures was done by the method of Zuker & Turner, as implemented in the mfold program. RESULTS: Phylogenetic tree analysis of HCV strains isolated in the South American region revealed the presence of a distinct genetic lineage inside genotype 1. Signature pattern analysis revealed that the presence of this lineage is consistent with the presence of a sequence signature in the 5'NCR of HCV strains isolated in South America. Comparisons of these results with the ones found for Europe or North America revealed that this sequence signature is characteristic of the South American region. CONCLUSION: Phylogentic analysis revealed the presence of a sequence signature in the 5'NCR of type 1 HCV strains isolated in South America. This signature is frequent enough in type 1 HCV populations circulating South America to be detected in a phylogenetic tree analysis as a distinct type 1 sub-population. The coexistence of distinct type 1 HCV subpopulations is consistent with quasispecies dynamics, and suggests that multiple coexisting subpopulations may allow the virus to adapt to its human host populations.

Inmunogenicidad y reactogenicidad de la vacuna cubana Quimiohib en lactantes sanos. Cárdenas. 2005 / Immunogenicity and reactogenecity of the cuban vaccine Quimiohib in health breastfed children. Cardenas. 2005

Las infecciones por el Haemophilus Influenzae Tipo B (Hib) son frecuentes en edades pediátricas, causando infecciones graves que llevan a la muerte. Al iniciarse la aplicación de la vacuna cubana contra este germen realizamos un estudio prospectivo, de corte longitudinal, con los lactantes sanos del policlínico “José A. Echeverría”, Cárdenas, para determinar la inmunogenicidad y reactogenicidad de esta vacuna. Nuestro universo fueron los niños nacidos entre el 1º. de septiembre y el 31 de octubre del 2004, quedando como muestra sólo 32 lactantes sanos. Para seleccionarlos aplicamos criterios de inclusión y exclusión; a los lactantes reclutados, previo consentimiento informado de sus padres, se les aplicó tres dosis de la vacuna cubana QuimiHib® según el esquema 2-4-6 meses, por vía intramuscular, en la cara anterolateral del muslo izquierdo. Los eventos adversos ocurridos en los tres días consecutivos a la vacuna, a los 7 y 30 días después de la administración de cada dosis se siguieron estrechamente por un médico especialista en Pediatría y la enfermera de vacunación. Calculamos los porcentajes de presentación de éstas, clasificándolas en leves, moderadas y severas.Determinamos a qué tiempo después de administradas las vacunas aparecieron con mayor frecuencia. La inmunogenicidad del producto se evaluó a los 30 días de culminada la serie completa de inmunización por las determinaciones de los títulos de anticuerpos IgG contra el Hib. Obtuvimos que las reacciones adversas en su mayoría leves se resolvieron sin aplicar medicamentos. Todos los niños que concluyeron el estudio adquirieron el nivel de anticuerpos requeridos

Inmunogenicidad y reactogenicidad de la vacuna cubana Quimiohib en lactantes sanos. Cárdenas. 2005 / Immunogenicity and reactogenecity of the cuban vaccine Quimiohib in health breastfed children. Cardenas. 2005

Las infecciones por el Haemophilus Influenzae Tipo B (Hib) son frecuentes en edades pediátricas, causando infecciones graves que llevan a la muerte. Al iniciarse la aplicación de la vacuna cubana contra este germen realizamos un estudio prospectivo, de corte longitudinal, con los lactantes sanos del policlínico “José A. Echeverría”, Cárdenas, para determinar la inmunogenicidad y reactogenicidad de esta vacuna. Nuestro universo fueron los niños nacidos entre el 1º. de septiembre y el 31 de octubre del 2004, quedando como muestra sólo 32 lactantes sanos. Para seleccionarlos aplicamos criterios de inclusión y exclusión; a los lactantes reclutados, previo consentimiento informado de sus padres, se les aplicó tres dosis de la vacuna cubana QuimiHib® según el esquema 2-4-6 meses, por vía intramuscular, en la cara anterolateral del muslo izquierdo. Los eventos adversos ocurridos en los tres días consecutivos a la vacuna, a los 7 y 30 días después de la administración de cada dosis se siguieron estrechamente por un médico especialista en Pediatría y la enfermera de vacunación. Calculamos los porcentajes de presentación de éstas, clasificándolas en leves, moderadas y severas.Determinamos a qué tiempo después de administradas las vacunas aparecieron con mayor frecuencia. La inmunogenicidad del producto se evaluó a los 30 días de culminada la serie completa de inmunización por las determinaciones de los títulos de anticuerpos IgG contra el Hib. Obtuvimos que las reacciones adversas en su mayoría leves se resolvieron sin aplicar medicamentos. Todos los niños que concluyeron el estudio adquirieron el nivel de anticuerpos requeridos.

The infections by Haemophilus Influenzae tipe b (Hib) are very frequent in paediatric ages, causing serious infections leading to death. When the application of the Cuban vaccine against this germ began, we carried out a longitudinal, prospective study with the healthy breastfed children of the Policlinic “José Antonio Echeverría”, Cardenas, to determine the immunogenicity and reactogenecity of this vaccine. Our universe was the children born between September 1 st and October 31 st , 2004, taking as sample only 32 healthy breastfed children. To select them we applied criteria of inclusion and exclusion; to the recruited children, with the previous informed consent of their parents, were applied three doses of the Cuban vaccine QuimiHib®, following the scheme 2-4-6 months, intramuscular way, on the anterior side of the right thigh. A specialist in paediatrics and the vaccinating nurse rigorously followed the adverse events taken place during the three consecutive days after vaccination, and during the 7-to-30 days period after the administration of each doses. We calculated the percentages of presentation of these events by levels, from moderated to severe. We determined at what time they appeared more frequently after vaccination, and we evaluated the immunogenicity of the product at the 30 th day of finishing the complete series of immunization by determination the titles of IgG antibodies against Hib. The adverse reactions, most of them insubstantial, were solved without applying drugs. All the children coming to the end of the treatment acquired the required level of antibodies.