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1.
Ecotoxicol Environ Saf ; 275: 116244, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38537480

RESUMO

A risk assessment on the aquatic toxicity of the plant biostimulant strigolactone mimic (2-(4-methyl-5-oxo-2,5-dihydro-furan-2-yloxy)-benzo[de]isoquinoline-1,3-dione (SL-6) was performed using a suite of standardised bioassays representing different trophic groups and acute and chronic endpoints. In freshwater, three trophic groups of algae, crustacea and fish were used. Whilst in seawater, algae (unicellular and macroalgae), Crustacea and Mollusca were employed. In addition, the genotoxicity of SL-6 was determined with the comet assessment performed on unicellular marine algae, oysters, and fish embryos. This was the first time ecotoxicity tests have been performed on SL-6. In freshwater, the lowest LOEC was measured in the unicellular algae at 0.31 mg/L SL-6. Although, similar LOEC values were found for embryo malformations and impacts on hatching rate in zebrafish (LOEC 0.31-0.33 mg/L). Consistent malformations of pericardial and yolk sac oedemas were identified in the zebrafish embryos at 0.31 mg/L. In marine species, the lowest LOEC was found for both Tisbe battagliai mortality and microalgae growth at an SL-6 concentration of 1.0 mg/L. Significant genotoxicity was observed above control levels at 0.0031 mg/L SL-6 in the unicellular algae and 0.001 mg/L SL-6 in the oyster and zebrafish larvae. When applying the simple risk assessment, based on the lowest NOECs and appropriate assessment factors, the calculated predicted no effect concentration (PNEC), for the ecotoxicity and the genotoxicity tests were 1.0 µg/L and 0.01 µg/L respectively.


Assuntos
Compostos Heterocíclicos com 3 Anéis , Lactonas , Poluentes Químicos da Água , Peixe-Zebra , Animais , Larva , Crustáceos , Testes de Mutagenicidade , Poluentes Químicos da Água/toxicidade
2.
Ecotoxicol Environ Saf ; 273: 116134, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38387143

RESUMO

The leaching of additives from plastics and elastomers (rubbers) has raised concerns due to their potential negative impacts on the environment and the development of antibiotic resistance. In this study, we investigated the effects of chemicals extracted from two types of rubber on microbiomes derived from a benthic sea urchin and two pelagic fish species. Additionally, we examined whether bacterial communities preconditioned with rubber-associated chemicals displayed adaptations to antibiotics. At the highest tested concentrations of chemicals, we observed reduced maximum growth rates and yields, prolonged lag phases, and increased alpha diversity. While the effects on alpha and beta diversity were not always conclusive, several bacterial genera were significantly influenced by chemicals from the two rubber sources. Subsequent exposure of sea urchin microbiomes preconditioned with rubber chemicals to the antibiotic ciprofloxacin resulted in decreased maximum growth rates. This indicates a more sensitive microbiome to ciprofloxacin when preconditioned with rubber chemicals. Although no significant interaction effects between rubber chemicals and ciprofloxacin exposure were observed in bacterial alpha and beta diversity, we observed log-fold changes in two bacterial genera in response to ciprofloxacin exposure. These findings highlight the structural and functional alterations in microbiomes originating from various marine species when exposed to rubber-associated chemicals and underscore the potential risks posed to marine life.


Assuntos
Microbiota , Borracha , Animais , Antibacterianos/toxicidade , Plásticos , Ciprofloxacina/toxicidade
3.
Environ Sci Technol ; 57(8): 3198-3205, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36799527

RESUMO

While adverse biological effects of acute high-dose ionizing radiation have been extensively investigated, knowledge on chronic low-dose effects is scarce. The aims of the present study were to identify hazards of low-dose ionizing radiation to Daphnia magna using multiomics dose-response modeling and to demonstrate the use of omics data to support an adverse outcome pathway (AOP) network development for ionizing radiation. Neonatal D. magna were exposed to γ radiation for 8 days. Transcriptomic analysis was performed after 4 and 8 days of exposure, whereas metabolomics and confirmative bioassays to support the omics analyses were conducted after 8 days of exposure. Benchmark doses (BMDs, 10% benchmark response) as points of departure (PODs) were estimated for both dose-responsive genes/metabolites and the enriched KEGG pathways. Relevant pathways derived using the BMD modeling and additional functional end points measured by the bioassays were overlaid with a previously published AOP network. The results showed that several molecular pathways were highly relevant to the known modes of action of γ radiation, including oxidative stress, DNA damage, mitochondrial dysfunction, protein degradation, and apoptosis. The functional assays showed increased oxidative stress and decreased mitochondrial membrane potential and ATP pool. Ranking of PODs at the pathway and functional levels showed that oxidative damage related functions had relatively low PODs, followed by DNA damage, energy metabolism, and apoptosis. These were supportive of causal events in the proposed AOP network. This approach yielded promising results and can potentially provide additional empirical evidence to support further AOP development for ionizing radiation.


Assuntos
Rotas de Resultados Adversos , Multiômica , Radiação Ionizante , Raios gama , Estresse Oxidativo
4.
Ecotoxicol Environ Saf ; 245: 114074, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36137423

RESUMO

Fish embryos can bioaccumulate and are particularly sensitive to a wide range of contaminants, which makes them suitable sentinels for environmental biomonitoring. However, fish embryos are very rarely utilized in environmental monitoring surveys, possibly due to their fragility and seasonality. In the present work, we assessed the applicability of caged lumpfish (Cyclopterus lumpus) eggs for in situ biomonitoring of exposure and effects of organic contaminants focusing on polyaromatic hydrocarbons and phenolic compounds. Fertilized eggs (1 dpf) were transplanted for 17-19 days at different locations that differed in terms of contaminant load, depths and weather conditions, namely at three stations close to the city of Trondheim (two harbour areas and a one in the Fjord) and three stations at a coastal aquaculture facility. High survival upon retrieval after deployment showed that lumpfish eggs are relatively robust and survive encaging in different environments. Bioaccumulation of organic contaminants (PAHs and phenolic compounds) was measured and potential effects on hatching, development, survival and larvae morphometry were determined. Chemical analyses showed that especially PAHs were effectively accumulated in eggs in contaminated sites, with concentrations of Æ©PAHs being 15 - 25 times higher in harbour areas compared to those at the aquaculture facility. A higher incidence of embryonic deformations was observed in the most polluted deployment location, but larvae morphometry revealed no evidence of toxicity related to pollutant body burden. In conclusion, the in-situ exposure method was proven to work well, making it attractive for implementations in environmental monitoring programs.


Assuntos
Poluentes Ambientais , Doenças dos Peixes , Perciformes , Animais , Bioacumulação , Peixes , Hidrocarbonetos , Oceanos e Mares , Qualidade da Água , Óvulo
5.
Appl Environ Microbiol ; 87(16): e0074321, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34085857

RESUMO

Extraintestinal pathogenic Escherichia coli (ExPEC) is a leading cause of human and animal infections worldwide. The utilization of selective and differential media to facilitate the isolation and identification of E. coli from complex samples, such as water, food, sediment, and gut tissue, is common in epidemiological studies. During a surveillance study, we identified an E. coli strain isolated from human blood culture that displayed atypical light cream-colored colonies in chromogenic agar and was unable to produce ß-glucuronidase and ß-galactosidase in biochemical tests. Genomic analysis showed that the strain belongs to sequence type 59 (ST59) and phylogroup F. The evaluation in silico of 104 available sequenced lineages of ST59 complex showed that most of them belong to serotype O1:K1:H7, are ß-glucuronidase negative, and harbor a virulent genotype associated with the presence of important virulence markers such as pap, kpsE, chuA, fyuA, and yfcV. Most of them were isolated from extraintestinal human infections in diverse countries worldwide and could be clustered/subgrouped based on papAF allele analysis. Considering that all analyzed strains harbor a virulent genotype and most do not exhibit biochemical behavior typical of E. coli, we report that they could be misclassified or underestimated, especially in epidemiological studies where the screening criteria rely only on typical biochemical phenotypes, as happens when chromogenic media are used. IMPORTANCE The use of selective and differential media guides presumptive bacterial identification based on specific metabolic traits that are specific to each bacterial species. When a bacterial specimen displays an unusual phenotype in these media, this characteristic may lead to bacterial misidentification or a significant delay in its identification, putting a patient at risk depending on the infection type. In the present work, we describe a virulent E. coli sequence type (ST59) that does not produce beta-glucuronidase (GUS negative), production of which is the metabolic trait widely used for E. coli presumptive identification in diverse differential media. The recognition of this unusual metabolic trait may help in the proper identification of ST59 isolates, the identification of their reservoir, and the evaluation of the frequency of these pathogens in places where automatic identification methods are not available.


Assuntos
Infecções por Escherichia coli/microbiologia , Escherichia coli/patogenicidade , Idoso de 80 Anos ou mais , Escherichia coli/classificação , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Fezes/microbiologia , Feminino , Proteínas de Fímbrias/genética , Proteínas de Fímbrias/metabolismo , Genótipo , Humanos , Filogenia , Virulência
6.
Ecotoxicol Environ Saf ; 222: 112553, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34325198

RESUMO

Pharmaceuticals are produced to inflict a specific physiological response in organisms. However, as only partially metabolized after administration, these types of compounds can also originate harmful side effects to non-target organisms. Additionally, there is still a lack of knowledge on the toxicological effects of legacy pharmaceuticals such as the antibiotic azithromycin. This macrolide occurs at high concentrations in the aquatic environment and can constitute a threat to aquatic organisms that are at the basis of the aquatic food chain, namely microalgae. This study established a high-throughput methodology to study the toxicity of azithromycin to the freshwater microalga Raphidocelis subcapitata. Flow cytometry and pulse amplitude modulated (PAM) fluorometry were used as screening tools. General toxicity was shown by effects in growth rate, cell size, cell complexity, cell viability and cell cycle. More specific outcomes were indicated by the analysis of mitochondrial and cytoplasmatic membrane potentials, DNA content, formation of ROS and LPO, natural pigments content and photosystem II performance. The specific mode of action (MoA) of azithromycin to crucial components of microalgae cells was revealed. Azithromycin had a negative impact on the regulation of energy dissipation at the PSII centers, along with an insufficient protection by the regulatory mechanisms leading to photodamage. The blockage of photosynthetic electrons led to ROS formation and consequent oxidative damage, affecting membranes and DNA. Overall, the used methodology exhibited its high potential for detecting the toxic MoA of compounds in microalgae and should be considered for future risk assessment of pharmaceuticals.


Assuntos
Clorofíceas , Microalgas , Poluentes Químicos da Água , Azitromicina/toxicidade , Água Doce , Poluentes Químicos da Água/toxicidade
7.
Int J Med Microbiol ; 309(1): 66-72, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30559068

RESUMO

Typical enteropathogenic Escherichia coli strains (tEPEC) cause attaching/effacing lesions in eukaryotic cells and produce the bundle-forming pilus (BFP), which interweaves and aggregates bacteria, resulting in the localized adherence (LA) pattern on eukaryotic cells. Previously, we identified tEPEC strains (serotype O119:H6) that exhibited LA simultaneously with an aggregative adherence (AA)-like pattern (LA/AA-like+). Remarkably, AA is characteristically produced by strains of enteroaggregative E. coli (EAEC), another diarrheagenic E. coli pathovar. In one LA/AA-like + strain (Ec404/03), we identified a conjugative plasmid containing the pil operon, which encodes the Pil fimbriae. Moreover, a pil operon associated with an AA pattern and plasmid transfer had been previously described in the EAEC C1096 strain. In this study, we investigated the occurrence of the two pilS alleles (pilSEc404 and pilSC1096) in tEPEC strains of different serotypes, origins and years of isolation. We also examined the potential relationship of pilS with the AA-like phenotype, its ability to be transferred by conjugation, and occurrence among strains of the other E. coli pathovars. The pilS alleles were found in 90 (55.2%) of 163 tEPEC strains, with pilSEc404 occurring more often (30.7%) than pilSC1096 (25.1%). About 21 tEPEC serotypes carried pilS. The pilS alleles were found in tEPEC strains from Chile, Peru and different Brazilian cities, with the oldest strain being isolated in 1966. No absolute correlation was found between the presence of pilS and the AA-like pattern. Conjugative pilS transfer was detected in 26.2% of pilSEc404+ strains and in 65.1% of pilSC1096+ strains, but only pilSEc404+ transconjugants were AA-like+, thus suggesting that the latter allele might need a different genetic background to express this phenotype. pilS was found in all other E. coli pathovars, where it was most prevalent in enterotoxigenic E. coli. More studies are needed to understand the mechanisms involved in the regulation of Pil expression and production.


Assuntos
Aderência Bacteriana/genética , Proteínas de Bactérias/genética , Escherichia coli Enteropatogênica/genética , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Fatores de Transcrição/genética , Alelos , Brasil , Chile , Conjugação Genética/genética , Escherichia coli Enteropatogênica/isolamento & purificação , Fímbrias Bacterianas/genética , Células HeLa , Humanos , Óperon , Peru , Plasmídeos , Sorogrupo , Virulência/genética
8.
Bull Environ Contam Toxicol ; 102(3): 341-346, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30600390

RESUMO

Effects of copper oxide nanoparticles (CuO NPs) were investigated in the midgut and fat body of Galleria mellonella. Fourth instar larvae were exposed to 10 µg Cu/L of CuO until becoming last instar larvae, and catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione-s-transferase (GST) and acetylcholinesterase (AChE) and metal accumulation were evaluated. Copper accumulation was observed in midgut and fat body tissues of G. mellonella larvae exposed to CuO NPs. CuO NPs increased CAT activities in midgut and fat body, while SOD activities were decreased. CuO NPs exhibited significant increases in GST activity in fat body, while no significant differences were observed in the midgut of G. mellonella larvae. AChE activity significantly decreased in the midgut of G. mellonella whereas there is no significant effect on fat body in CuO NPs exposed larvae. In overall, these findings demonstrate that tissue accumulation and oxidative stress that is countered by antioxidant enzymes occur when G. mellonella larvae exposed to environmental concentration of CuO nanoparticles.


Assuntos
Antioxidantes/metabolismo , Cobre/metabolismo , Mariposas/efeitos dos fármacos , Nanopartículas/toxicidade , Acetilcolinesterase/metabolismo , Animais , Catalase/metabolismo , Cobre/toxicidade , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Larva/efeitos dos fármacos , Larva/metabolismo , Nanopartículas Metálicas , Mariposas/metabolismo , Estresse Oxidativo , Óxidos , Superóxido Dismutase/metabolismo
9.
Ecotoxicol Environ Saf ; 154: 19-26, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29453161

RESUMO

The biological effects of gamma radiation may exert damage beyond that of the individual through its deleterious effects on reproductive function. Impaired reproductive performance can result in reduced population size over consecutive generations. In a continued effort to investigate reproductive and heritable effects of ionizing radiation, we recently demonstrated adverse effects and genomic instability in progeny of parents exposed to gamma radiation. In the present study, genotoxicity and effects on the reproduction following subchronic exposure during a gametogenesis cycle to 60Co gamma radiation (27 days, 8.7 and 53 mGy/h, total doses 5.2 and 31 Gy) were investigated in the adult wild-type zebrafish (Danio rerio). A significant reduction in embryo production was observed one month after exposure in the 53 mGy/h exposure group compared to control and 8.7 mGy/h. One year later, embryo production was significantly lower in the 53 mGy/h group compared only to control, with observed sterility, accompanied by a regression of reproductive organs in 100% of the fish 1.5 years after exposure. Histopathological examinations revealed no significant changes in the testis in the 8.7 mGy/h group, while in 62.5% of females exposed to this dose rate the oogenesis was found to be only at the early previtellogenic stage. The DNA damage determined in whole blood, 1.5 years after irradiation, using a high throughput Comet assay, was significantly higher in the exposed groups (1.2 and 3-fold increase in 8.7 and 53 mGy/h females respectively; 3-fold and 2-fold increase in 8.7 and 53 mGy/h males respectively) compared to controls. A significantly higher number of micronuclei (4-5%) was found in erythrocytes of both the 8.7 and 53 mGy/h fish compared to controls. This study shows that gamma radiation at a dose rate of ≥ 8.7 mGy/h during gametogenesis causes adverse reproductive effects and persistent genotoxicity (DNA damage and increased micronuclei) in adult zebrafish.


Assuntos
Dano ao DNA , Gametogênese/efeitos da radiação , Raios gama/efeitos adversos , Reprodução/efeitos dos fármacos , Peixe-Zebra/genética , Animais , Ensaio Cometa , Relação Dose-Resposta à Radiação , Feminino , Gametogênese/genética , Instabilidade Genômica/efeitos da radiação , Masculino , Óvulo/efeitos da radiação , Reprodução/genética , Testículo/efeitos da radiação , Peixe-Zebra/crescimento & desenvolvimento
10.
Environ Res ; 159: 564-578, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28892785

RESUMO

Gamma radiation represents a potential health risk to aquatic and terrestrial biota, due to its ability to ionize atoms and molecules in living tissues. The effects of exposure to 60Co gamma radiation in zebrafish (Danio rerio) were studied during two sensitive life stages: gametogenesis (F0: 53 and 8.7mGy/h for 27 days, total doses 31 and 5.2Gy) and embryogenesis (9.6mGy/h for 65h; total dose 0.62Gy). Progeny of F0 exposed to 53mGy/h showed 100% mortality occurring at the gastrulation stage corresponding to 8h post fertilization (hpf). Control and F0 fish exposed to 8.7mGy/h were used to create four lines in the first filial generation (F1): control, G line (irradiated during parental gametogenesis), E line (irradiated during embryogenesis) and GE line (irradiated during parental gametogenesis and embryogenesis). A statistically significant cumulative mortality of GE larva (9.3%) compared to controls was found at 96 hpf. E line embryos hatched significantly earlier compared to controls, G and GE (48-72 hpf). The deformity frequency was higher in G and GE, but not E line compared to controls at 72 hpf. One month after parental irradiation, the formation of reactive oxygen species (ROS) was increased in the G line, but did not significantly differ from controls one year after parental irradiation, while at the same time point it was significantly increased in the directly exposed E and GE lines from 60 to 120 hpf. Lipid peroxidation (LPO) was significantly increased in the G line one year after parental irradiation, while significant increase in DNA damage was detected in both the G and GE compared to controls and E line at 72 hpf. Radiation-induced bystander effects, triggered by culture media from tissue explants and observed as influx of Ca2+ ions through the cellular membrane of the reporter cells, were significantly increased in 72 hpf G line progeny one month after irradiation of the parents. One year after parental irradiation, the bystander effects were increased in the E line compared to controls, but not in progeny of irradiated parents (G and GE lines). Overall, this study showed that irradiation of parents can result in multigenerational oxidative stress and genomic instability in irradiated (GE) and non-irradiated (G) progeny of irradiated parents, including increases in ROS formation, LPO, DNA damage and bystander effects. The results therefore highlight the necessity for multi- and transgenerational studies to assess the environmental impact of gamma radiation.


Assuntos
Gametogênese/efeitos da radiação , Raios gama/efeitos adversos , Instabilidade Genômica/efeitos da radiação , Reprodução/efeitos da radiação , Peixe-Zebra/fisiologia , Animais , Embrião não Mamífero/efeitos da radiação , Peixe-Zebra/genética
11.
Infect Immun ; 84(4): 1112-1122, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26831466

RESUMO

The expression of flagella correlates with different aspects of bacterial pathogenicity, ranging from adherence to host cells to activation of inflammatory responses by the innate immune system. In the present study, we investigated the role of flagella in the adherence of an atypical enteropathogenic Escherichia coli (aEPEC) strain (serotype O51:H40) to human enterocytes. Accordingly, isogenic mutants deficient in flagellin (FliC), the flagellar structural subunit; the flagellar cap protein (FliD); or the MotAB proteins, involved in the control of flagellar motion, were generated and tested for binding to differentiated Caco-2 cells. Binding of the aEPEC strain to enterocytes was significantly impaired in strains with the fliCa nd fliD genes deleted, both of which could not form flagella on the bacterial surface. A nonmotile but flagellated MotAB mutant also showed impaired adhesion to Caco-2 cells. In accordance with these observations, adhesion of a EPEC strain 1711-4 to Caco-2 cells was drastically reduced after the treatment of Caco-2 cells with purified FliD. In addition, incubation of a EPEC bacteria with specific anti-FliD serum impaired binding to Caco-2 cells. Finally, incubation of Caco-2 cells with purified FliD, followed by immunolabeling, showed that the protein was specifically bound to the microvillus tips of differentiated Caco-2 cells. The a EPEC FliD or anti-FliD serum also reduced the adherence of prototype typical enteropathogenic, enterohemorrhagic, and enterotoxigenic E. coli strains to Caco-2 cells. In conclusion, our findings further strengthened the role of flagella in the adherence of a EPEC to human enterocytes and disclosed the relevant structural and functional involvement of FliD in the adhesion process.


Assuntos
Aderência Bacteriana/fisiologia , Proteínas de Bactérias/metabolismo , Enterócitos/microbiologia , Escherichia coli Enteropatogênica/fisiologia , Microvilosidades/fisiologia , Animais , Anticorpos , Proteínas de Bactérias/genética , Células CACO-2 , Enterócitos/fisiologia , Escherichia coli Enteropatogênica/genética , Humanos , Imuno-Histoquímica , Camundongos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Mutação , Coelhos , Proteínas Recombinantes
12.
Int J Med Microbiol ; 306(3): 152-64, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27083266

RESUMO

Enteropathogenic Escherichia coli (EPEC) induce attaching and effacing (A/E) lesions in enterocytes and produce the bundle-forming pilus (BFP) contributing to the localized adherence (LA) pattern formation on HeLa cells. Enteroaggregative E. coli (EAEC) produce aggregative adherence (AA) on HeLa cells and form prominent biofilms. The ability to produce LA or AA is an important hallmark to classify fecal E. coli isolates as EPEC or EAEC, respectively. E. coli strains of serotype O119:H6 exhibit an LA+ phenotype and have been considered as comprising a clonal group of EPEC strains. However, we have recently identified O119:H6 EPEC strains that produce LA and an AA-like pattern concurrently (LA/AA-like+). In this study, we evaluated the relatedness of three LA/AA-like+ and three LA+ O119:H6 strains by comparing their virulence and genotypic properties. We first found that the LA/AA-like+ strains induced actin accumulation in HeLa cells (indicative of A/E lesions formation) and formed biofilms on abiotic surfaces more efficiently than the LA+ strains. MLST analysis showed that the six strains all belong to the ST28 complex. All strains carried multiple plasmids, but as plasmid profiles were highly variable, this cannot be used to differentiate LA/AA-like+ and LA+ strains. We further obtained their draft genome sequences and the complete sequences of four plasmids harbored by one LA/AA-like+ strain. Analysis of these sequences and comparison with 37 fully sequenced E. coli genomes revealed that both O119:H6 groups belong to the E. coli phylogroup B2 and are very closely related with only 58-67 SNPs found between LA/AA-like+ and LA+ strains. Search of the draft sequences of the six strains for adhesion-related genes known in EAEC and other E. coli pathotypes detected no genes specifically present in LA/AA-like+ strains. Unexpectedly however, we found that a large plasmid distinct from pEAF is responsible for the AA-like phenotype of the LA/AA-like+ strains. Although we have not identified any plasmid genes specifically present in all LA/AA-like+ strains and absent in the LA+ strains, these results suggest the presence of an unknown mechanism to promote the AA-like pattern production and biofilm formation by the LA/AA-like+ strains. Because their ability to produce A/E lesions and biofilm concomitantly could exacerbate the clinical condition of the patient and lead to persistent diarrhea, the mechanism underlying the enhanced biofilm formation by the LA/AA-like+ O119:H6 strains and their spread and involvement in severe diarrheal diseases should be more intensively investigated.


Assuntos
Adesinas de Escherichia coli/metabolismo , Escherichia coli Enteropatogênica/genética , Escherichia coli Enteropatogênica/patogenicidade , Virulência , Adesinas de Escherichia coli/genética , Biofilmes , DNA Bacteriano/genética , Escherichia coli Enteropatogênica/classificação , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Fezes/microbiologia , Genes Bacterianos , Células HeLa , Humanos , Tipagem de Sequências Multilocus , Filogenia , Plasmídeos/genética , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Sorogrupo
13.
Environ Sci Technol ; 50(21): 11994-12003, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27704796

RESUMO

Emamectin benzoate (EMB) is an antisea lice chemical widely used in the aquaculture that may also unintentionally affect nontarget crustaceans in the environment. Although the adverse effects of this compound are well documented in various species, the full modes of action (MoAs) are still not well characterized. The current study was therefore conducted to characterize the MoAs of EMB and link perturbations of key toxicological pathways to adverse effects in the model freshwater crustacean Daphnia magna. Effects on molting and survival were determined after 48 h exposure to EMB, whereas global transcriptional changes and the ecdysone receptor (EcR) binding potency was determined to characterize the MoA. The results showed that the molting frequency and survival of D. magna decreased in a concentration-dependent manner, and the observed changes could not be attributed to direct interactions with the EcR. Major MoAs such as activation of glutamate-gated chloride channels and gamma-aminobutyric acid signaling, disruption of neuroendocrine regulation of molting, perturbation of energy homeostasis, suppression of DNA repair and induction of programmed cell death were observed by transcriptional analysis and successfully linked to the adverse effects. This study has demonstrated that acute exposure to intermediate and high pM levels of EMB may pose hazards to nontarget crustaceans in the aquatic environment.


Assuntos
Daphnia/efeitos dos fármacos , Ivermectina/análogos & derivados , Poluentes Químicos da Água/toxicidade , Animais , Ivermectina/toxicidade , Muda/efeitos dos fármacos , Transcriptoma , Ácido gama-Aminobutírico
14.
BMC Microbiol ; 14: 299, 2014 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-25527183

RESUMO

BACKGROUND: Attachment is essential to maintain bacteria at their preferential intestinal colonization sites. There is little information on the influence of different environmental conditions in the interaction of atypical enteropathogenic Escherichia coli (aEPEC) strains with epithelial cells. In this study, we evaluated the effect of different glucose (5 and 25 mM) and CO2 (0.03 and 5%) concentrations and presence of bile salts on the adhesiveness of the aEPEC strain 1551-2. RESULTS: We found that a CO2-enriched atmosphere enhanced the adhesiveness of the aEPEC 1551-2 strain independently of glucose concentrations or presence of bile salts. Conversely, the presence of high glucose concentration altered the original localized adherence (LA) pattern observed at 5 mM glucose, which is characterized by the formation of compact bacterial clusters, to a hybrid adherence pattern (LA and an aggregative adherence-like pattern). In addition, at high glucose concentration, there was increased expression of the fimA gene, which encodes the major subunit of type 1 pilus (T1P), and an isogenic fimA mutant displayed only LA. The presence of bile salts did not interfere with the adhesion properties of the 1551-2 strain to HeLa cells. CONCLUSIONS: Our data suggest that a CO2-enriched atmosphere could favor aEPEC adhesion to the host cells, whereas enhanced T1P production under high glucose concentration could allow bacteria to access more extensive intestinal colonization sites in the host at the beginning of the infectious process.


Assuntos
Aderência Bacteriana , Escherichia coli Enteropatogênica/fisiologia , Exposição Ambiental , Células Epiteliais/microbiologia , Interações Hospedeiro-Patógeno , Ácidos e Sais Biliares/metabolismo , Dióxido de Carbono/metabolismo , Glucose/metabolismo , Células HeLa , Humanos
15.
Radiol Case Rep ; 19(7): 2891-2894, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38721390

RESUMO

Aortic coarctation is a rare cause of secondary hypertension (<1% cases) and can be challenging to detect due to its few clinical manifestations. Early diagnosis and treatment are important because patients with unmanaged aortic coarctation are at increased risk of cardiovascular complications and have a reduced life expectancy. We describe a case of secondary hypertension in a young adult female caused by aortic coarctation, first detected in a general practitioner setting, resulting in the need for a left subclavian-carotid bypass vascular surgery and a descending aortic stent vascular surgery. This case highlights the critical role that proximity medicine in general practice can have in improving the early detection of clinically silent conditions by routinely monitoring blood pressure and other vital parameters, and the increasing importance of medical imaging in assisting early diagnosis and guiding the surgical management of complex cases.

16.
Front Public Health ; 12: 1330370, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38596518

RESUMO

Introduction: Many of the essential practices in palliative care (PC) had to be adapted to the COVID-19 pandemic. This global spread of the infectious respiratory disease, caused by SARS-CoV-2, created unprecedented obstacles. The aim of this research was to comprehensively assess the experiences and perceptions of healthcare professionals, individuals, and families in palliative and end-of-life situations during the COVID-19 pandemic. Methods: A scoping review was conducted using the databases CINAHL Complete, MEDLINE, Scopus, SciELO, Cochrane Central Register of Controlled Trials, Psychology and Behavioral Sciences, MEDIClatina, and Portugal's Open Access Scientific Repository. The review followed the JBI® methodological approach for scoping reviews. Results: Out of the initially identified 999 articles, 22 studies were included for analysis. The deprivation of relationships due to the safety protocols required to control the spread of COVID-19 was a universally perceived experience by healthcare professionals, individuals in PC, and their families. Social isolation, with significant psychological impact, including depersonalization and despair, was among the most frequently reported experiences by individuals in palliative situation. Despite healthcare professionals' efforts to mitigate the lack of relationships, the families of these individuals emphasized the irreplaceability of in-person bedside contact. Systematic review registration: https://osf.io/xmpf2/.


Assuntos
COVID-19 , Cuidados Paliativos , Humanos , Cuidados Paliativos/psicologia , COVID-19/terapia , COVID-19/epidemiologia , Pandemias , SARS-CoV-2 , Pessoal de Saúde/psicologia
17.
bioRxiv ; 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38352511

RESUMO

Atypical enteropathogenic Escherichia coli (aEPEC) is a significant cause of diarrhea in developing countries. Some aEPEC strains, including the Brazilian representative strain of serotype O51:H40 called aEPEC 1711-4, can use flagella to attach to, invade, and persist in T84 and Caco-2 intestinal cells. They can even translocate from the gut to extraintestinal sites in a rat model. Although various aspects of the virulence of this strain were studied and the requirement of the T3SS for the efficiency of the invasion process was demonstrated, the expression of the LEE genes during the invasion and intracellular persistence remains unclear. To address this, the expression of flagella and the different LEE operons was evaluated during kinetic experiments of the interaction of aEPEC 1711-4 with enterocytes in vitro. The genome of the strain was also sequenced. The results showed that flagella expression remained unchanged, but the expression of eae and escJ increased during the early interaction and invasion of aEPEC 1711-4 into Caco-2 cells, and there was no change 24 hours post-infection during the persistence period. The number of pedestal-like structures formed on HeLa cells also increased during the 24-hour analysis. No known gene related to the invasion process was identified in the genome of aEPEC 1711-4, which was shown to belong to the global EPEC lineage 10. These findings suggest that LEE components and the intimate adherence promoted by intimin are necessary for the invasion and persistence of aEPEC 1711-4, but the detailed mechanism needs further study.

18.
Chemosphere ; 357: 141918, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38614394

RESUMO

Aeromonas spp. are frequently encountered in aquatic environments, with Aeromonas veronii emerging as an opportunistic pathogen causing a range of diseases in both humans and animals. Recent reports have raised public health concerns due to the emergence of multidrug-resistant Aeromonas spp. This is particularly noteworthy as these species have demonstrated the ability to acquire and transmit antimicrobial resistance genes (ARGs). In this study, we report the genomic and phenotypic characteristics of the A. veronii TR112 strain, which harbors a novel variant of the Vietnamese Extended-spectrum ß-lactamase-encoding gene, blaVEB-28, and two mcr variants recovered from an urban river located in the Metropolitan Region of São Paulo, Brazil. A. veronii TR112 strain exhibited high minimum inhibitory concentrations (MICs) for ceftazidime (64 µg/mL), polymyxin (8 µg/mL), and ciprofloxacin (64 µg/mL). Furthermore, the TR112 strain demonstrated adherence to HeLa and Caco-2 cells within 3 h, cytotoxicity to HeLa cells after 24 h of interaction, and high mortality rates to the Galleria mellonella model. Genomic analysis showed that the TR112 strain belongs to ST257 and presented a range of ARGs conferring resistance to ß-lactams (blaVEB-28, blaCphA3, blaOXA-912) and polymyxins (mcr-3 and mcr-3.6). Additionally, we identified a diversity of virulence factor-encoding genes, including those encoding mannose-sensitive hemagglutinin (Msh) pilus, polar flagella, type IV pili, type II secretion system (T2SS), aerolysin (AerA), cytotoxic enterotoxin (Act), hemolysin (HlyA), hemolysin III (HlyIII), thermostable hemolysin (TH), and capsular polysaccharide (CPS). In conclusion, our findings suggest that A. veronii may serve as an environmental reservoir for ARGs and virulence factors, highlighting its importance as a potential pathogen in public health.


Assuntos
Aeromonas veronii , Antibacterianos , Testes de Sensibilidade Microbiana , Rios , beta-Lactamases , beta-Lactamases/genética , beta-Lactamases/metabolismo , Humanos , Antibacterianos/farmacologia , Rios/microbiologia , Aeromonas veronii/genética , Aeromonas veronii/isolamento & purificação , Aeromonas veronii/efeitos dos fármacos , Brasil , Células HeLa , Células CACO-2 , Animais , Farmacorresistência Bacteriana Múltipla/genética
19.
Vet Res Commun ; 48(3): 1755-1768, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38546809

RESUMO

Escherichia coli (E. coli) are widely related to pyometra and cystitis in dogs, and these infections can occur simultaneously. The goal of this study was to determine genetic and pathogenic insights of 14 E. coli isolated simultaneously from pyometra content and bladder urine of seven bitches. To achieve this, in silico and in vitro comparative analyses were conducted. Whole-genome comparisons demonstrated that E. coli isolated from pyometra and urine of the same animal were predominantly genetic extraintestinal E. coli clones belonging to the same Sequence Type and phylogroup. The E. coli clones identified in this study included ST372, ST457, ST12, ST127, ST646, and ST961. Five isolates (35.7%) belonged to the ST12 complex. Except for two E. coli, all other isolates belonged to the B2 Clermont phylogroup. Interestingly, some genomes of E. coli from urine carried more virulence genes than those E. coli from pyometra. Both pyometra and urine E. coli isolates demonstrated a strong affinity for adhering to HeLa and T24 cells, with a low affinity for invading them. However, certain isolates from urine exhibited a greater tendency to adhere to T24 cells in qualitative and quantitative assays compared to isolates from pyometra. In conclusion, this study revealed the high genomic similarity between pyometra and urine E. coli isolates, as well as the virulent capacity of both to colonize endometrial and urothelial cells. The findings of this study underscore the importance of concurrently managing both infections clinically and could potentially contribute to future resources for the prevention of cystitis and pyometra.


Assuntos
Doenças do Cão , Infecções por Escherichia coli , Escherichia coli , Piometra , Animais , Cães , Piometra/veterinária , Piometra/microbiologia , Piometra/urina , Feminino , Doenças do Cão/microbiologia , Doenças do Cão/urina , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Infecções por Escherichia coli/veterinária , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/urina , Genoma Bacteriano , Filogenia
20.
Infect Immun ; 81(10): 3793-802, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23897608

RESUMO

Atypical enteropathogenic Escherichia coli (aEPEC) strains are diarrheal pathogens that lack bundle-forming pilus production but possess the virulence-associated locus of enterocyte effacement. aEPEC strain 1551-2 produces localized adherence (LA) on HeLa cells; however, its isogenic intimin (eae) mutant produces a diffuse-adherence (DA) pattern. In this study, we aimed to identify the DA-associated adhesin of the 1551-2 eae mutant. Electron microscopy of 1551-2 identified rigid rod-like pili composed of an 18-kDa protein, which was identified as the major pilin subunit of type 1 pilus (T1P) by mass spectrometry analysis. Deletion of fimA in 1551-2 affected biofilm formation but had no effect on adherence properties. Analysis of secreted proteins in supernatants of this strain identified a 150-kDa protein corresponding to SslE, a type 2 secreted protein that was recently reported to be involved in biofilm formation of rabbit and human EPEC strains. However, neither adherence nor biofilm formation was affected in a 1551-2 sslE mutant. We then investigated the role of the EspA filament associated with the type 3 secretion system (T3SS) in DA by generating a double eae espA mutant. This strain was no longer adherent, strongly suggesting that the T3SS translocon is the DA adhesin. In agreement with these results, specific anti-EspA antibodies blocked adherence of the 1551-2 eae mutant. Our data support a role for intimin in LA, for the T3SS translocon in DA, and for T1P in biofilm formation, all of which may act in concert to facilitate host intestinal colonization by aEPEC strains.


Assuntos
Aderência Bacteriana/fisiologia , Biofilmes/crescimento & desenvolvimento , Escherichia coli Enteropatogênica/fisiologia , Fímbrias Bacterianas/fisiologia , Escherichia coli Enteropatogênica/genética , Escherichia coli Enteropatogênica/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica/fisiologia , Células HeLa , Humanos
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