RESUMO
Aedes aegypti chemical control remains an indispensable alternative to prevent dengue, Zika, and chikungunya outbreaks in Havana, Cuba. The city of Havana requires constant surveillance because of its bioecological characteristics that favor the proliferation of mosquito vectors of these viruses, which constitutes a high risk to the health of its inhabitants. The goal of this study was to determine the impact of the stopping of temephos applications during the 2 years of the COVID-19 pandemic on the level of susceptibility of Ae. aegypti in 5 municipalities of Havana, Cuba. Larval susceptibility was evaluated by bioassays as described by the World Health Organization. All Ae. aegypti populations tested showed high resistance to temephos. The National Control Program of Ae. aegypti in Cuba will need to promote insecticide rotation policies to prevent the evolution of temephos resistance in Havana.
Assuntos
Aedes , Resistência a Inseticidas , Inseticidas , Temefós , Animais , Cuba , Inseticidas/farmacologia , Mosquitos Vetores , Larva/crescimento & desenvolvimento , COVID-19/prevenção & controle , Controle de MosquitosRESUMO
Zoonotic human infections with Ancylostoma ceylanicum have recently been reported in the Americas. We used archived human stool samples to study the geographic distribution of human infections with A. ceylanicum and anthropophilic hookworms in different geoclimatic regions (coastal, Andean, and Amazon) of Ecuador. We analyzed retrospectively archived human stool samples from five studies previously screened for hookworm infection by microscopy, of which four included hookworm-positive samples only and one involved hookworm-negative samples to increase geographic distribution of sampling. Stools were analyzed using multi-parallel quantitative polymerase chain reaction (qPCR) assays to detect Necator americanus, Ancylostoma duodenale, A. ceylanicum, Ascaris lumbricoides, Trichuris trichiura, and Strongyloides stercoralis. Sequencing was done for the A. ceylanicum cox1 gene. A total of 132 samples were analyzed, of which 69 (52.3%) were from hookworm-positive and 63 (47.7%) from hookworm-negative individuals by microscopy. Overall, 82.6% of microscopy-positive samples and 33.3% of microscopy-negative samples were positive for hookworm by qPCR. Of microscopy-positive samples, 36.2% were A. ceylanicum, 37.7% A. duodenale, and 33.3% N. americanus, whereas equivalent proportions for microscopy-negative samples were 1.6%, 31.7%, and 1.6%, respectively. Ancylostoma duodenale was the most widely dispersed geographically, followed by N. americanus. Ancylostoma ceylanicum was least dispersed but was detected in coastal and Amazon regions. In conclusion, human infections with A. ceylanicum, A. duodenale, and N. americanus were detected in different geoclimatic regions of Ecuador. Additional studies are required to further define the epidemiology of human A. ceylanicum infections, but the potentially widespread presence of this helminth in human populations in Ecuador has implications for hookworm control strategies.
Assuntos
Ancilostomíase , Infecções por Uncinaria , Animais , Humanos , Ancylostoma/genética , Ancylostomatoidea , Ancilostomíase/epidemiologia , Ancilostomíase/diagnóstico , Estudos Retrospectivos , Equador/epidemiologia , Infecções por Uncinaria/epidemiologia , Zoonoses/epidemiologia , FezesRESUMO
Babesiosis is a protozoan disease acquired by the bite of different species of ticks. More than 100 Babesia spp. infect wild and domestic animals worldwide, but only a few have been documented to infect humans. Generally, babesiosis is asymptomatic in immunocompetent persons; however, in immunocompromised can be life-threatening. A 13-year-old boy from the Amazon region presented with a 3-month evolution of fever, chills, general malaise, and arthralgia accompanied by anemia and jaundice. In the last 4 years was diagnosed with chronic kidney failure. By nested-PCR using 18S RNA ribosomal gene as target and DNA sequencing, the phylogenetic analysis showed Babesia bigemina as the causative agent in the blood. Treatment with oral quinine plus clindamycin for six continuous weeks was effective with no relapse occurring during 12 months of follow-up. This is the second human case in Ecuador but the first caused by the zoonotic B. bigemina which confirms the existence of active transmission that should alert public health decision-making authorities on the emergence of this zoonosis and the need for research to determine strategies to reduce tick exposure.
Assuntos
Babesia , Babesiose , Carrapatos , Animais , Masculino , Humanos , Adolescente , Babesia/genética , Babesiose/diagnóstico , Equador , FilogeniaRESUMO
Microbial bioemulsifiers are molecules of amphiphilic nature and high molecular weight that are efficient in emulsifying two immiscible phases such as water and oil. These molecules are less effective in reducing surface tension and are synthesized by bacteria, yeast and filamentous fungi. Unlike synthetic emulsifiers, microbial bioemulsifiers have unique advantages such as biocompatibility, non-toxicity, biodegradability, efficiency at low concentrations and high selectivity under different conditions of pH, temperature and salinity. The adoption of microbial bioemulsifiers as alternatives to their synthetic counterparts has been growing in ongoing research. This article analyzes the production of microbial-based emulsifiers, the raw materials and fermentation processes used, as well as the scale-up and commercial applications of some of these biomolecules. The current trend of incorporating natural compounds into industrial formulations indicates that the search for new bioemulsifiers will continue to increase, with emphasis on performance improvement and economically viable processes.
Assuntos
Bactérias , Emulsificantes , Bactérias/genética , Fermentação , Peso Molecular , TensoativosRESUMO
Oil spills in aquatic ecosystems cause irreparable damage to marine life and the coastal populations of affected areas. In recent years, chemical dispersants have been extensively used to remedy these impacted ecosystems, although these agents have been increasingly restricted due to their toxic potential. In this context, biosurfactants are emerging as a promising alternative to chemical dispersants, which have some advantages including low toxicity, high biodegradability and good ecological acceptability. Thus, this study aimed to the production of biosurfactant by the bacteria Serratia marcescens UCP 1549 for application as biodispersant. The experiment was carried out using wheat bran as substrate in solid-state fermentation (SSF) as low-cost technology. Biosurfactant production was verified by the reduction of surface tension (28.4 mN/m) and interfacial tension (4.1 mN/m) with n-hexadecane. Also, promising result of emulsification (94%) with burned motor oil was obtained. Acid precipitation yielded 52.0â g/kg dry substrate of biosurfactant, that was identified as an anionic compound of a lipopeptide nature by the Zeta potential and FTIR spectrum, respectively. The biomolecule showed stability under extreme conditions of temperature, pH and salinity, as well as low toxicity against the microcrustacean Artemia salina. In addition, the biosurfactant demonstrated excellent properties to dispersing burned motor oil in water (ODA = 50.24 cm2) and to washing of marine stones (100% removal of burned motor oil). Therefore, these results confirm SSF as a sustainable technology for the production of biodispersant by S. marcescens UCP 1549, promising in the bioremediation of marine ecosystems impacted by petroderivatives.
Assuntos
Poluição por Petróleo , Petróleo , Biodegradação Ambiental , Ecossistema , Fermentação , Serratia marcescens , Tensoativos/químicaRESUMO
This work aimed to investigate the production of prodigiosin by S. marcescens UCP 1549 in solid-state fermentation (SSF), as a sustainable alternative for reducing the production costs and environmental impact. Thus, different agro-industrial substrates were used in the formulation of the prodigiosin production medium, obtaining the maximum yield of pigment (119.8 g/kg dry substrate) in medium consisting of 5 g wheat bran, 5% waste soybean oil and saline solution. The pigment was confirmed as prodigiosin by the maximum absorbance peak at 535 nm, Rf 0.9 in TLC, and the functional groups by infrared spectrum (FTIR). Prodigiosin demonstrated stability at different values of temperature, pH and NaCl concentrations and antimicrobial properties, as well as not show any toxicity. These results confirm the applicability of SSF as a sustainable and promising technology and wheat bran as potential agrosubstrate to produce prodigiosin, making the bioprocess economic and competitive for industrial purposes.
Assuntos
Microbiologia Industrial , Prodigiosina , Serratia marcescens , Antibacterianos/biossíntese , Meios de Cultura/química , Fermentação , Microbiologia Industrial/métodos , Prodigiosina/biossíntese , Serratia marcescens/metabolismoRESUMO
BACKGROUND: The present study describes the production of biosurfactant (BS) and emulsifier (BE) by the filamentous fungus Mucor hiemalis UCP 0039, as well as the characterization and stability of the both biomolecules for environmental or industrial applications. RESULTS: Biosurfactants and bioemulsifiers are amphiphilic compounds and are produced as extracellular molecules. The results showed that bioproduct obtained by shaker condition reduced the water surface tension of 72 to 32 mN/m and reached an emulsification index of 96%, while the static cultivation resulted in a biomolecule with a surface tension of 40 mN/m and an emulsification index of 96%, suggesting the production of a biosurfactant and bioemulsifier, respectively. The compounds showed glycolipid nature but the biosurfactant presented cationic charge, while the bioemulsifier, anionic charge. Thus, the results confirmed that M. hiemalis produced two distinct biomolecules under different parameters and in the same culture medium. CONCLUSIONS: It is the first time that biosurfactant and emulsifier production has been described in the same medium and under different physical conditions by Mucor hiemalis. Both biomolecules showed thermal stability, as well as have significant effect on the viscosity of hydrophobic compounds, indicating the excellent potential for environmental safety or industrial applications to improve the efficiency of sustainable and economic technologies.
Assuntos
Tensoativos/metabolismo , Emulsificantes/metabolismo , Mucor/metabolismo , Solo , Tensoativos , Óleo de SojaRESUMO
We investigated the influence of corn steep liquor (CSL) and cassava waste water (CWW) as carbon and nitrogen sources on the morphology and production of biomass and chitosan by Mucor subtilissimus UCP 1262 and Lichtheimia hyalospora UCP 1266. The highest biomass yields of 4.832 g/L (M. subtilissimus UCP 1262) and 6.345 g/L (L. hyalospora UCP 1266) were produced in assay 2 (6% CSL and 4% CWW), factorial design 22, and also favored higher chitosan production (32.471 mg/g) for M. subtilissimus. The highest chitosan production (44.91 mg/g) by L. hyalospora (UCP 1266) was obtained at the central point (4% of CWW and 6% of CSL). The statistical analysis, the higher concentration of CSL, and lower concentration of CWW significantly contributed to the growth of the strains. The FTIR bands confirmed the deacetylation degree of 80.29% and 83.61% of the chitosan produced by M. subtilissimus (UCP 1262) and L. hyalospora (UCP 1266), respectively. M. subtilissimus (UCP 1262) showed dimorphism in assay 4-6% CSL and 8% CWW and central point. L. hyalospora (UCP 1266) was optimized using a central composite rotational design, and the highest yield of chitosan (63.18 mg/g) was obtained in medium containing 8.82% CSL and 7% CWW. The experimental data suggest that the use of CSL and CWW is a promising association to chitosan production.
Assuntos
Quitosana/metabolismo , Mucor/crescimento & desenvolvimento , Mucorales/crescimento & desenvolvimento , Acetilação , Biomassa , Carbono/metabolismo , Manihot/química , Mucor/metabolismo , Mucorales/metabolismo , Nitrogênio/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Águas Residuárias/química , Zea mays/químicaRESUMO
BACKGROUND: The use of agro-industrial wastes to produce high value-added biomolecules such as biosurfactants is a promising approach for lowering the total costs of production. This study aimed to produce biosurfactants using Rhizopus arrhizus UCP 1607, with crude glycerol (CG) and corn steep liquor (CSL) as substrates. In addition, the biomolecule was characterized, and its efficiency in removing petroderivatives from marine soil was investigated. RESULTS: A 22 factorial design was applied, and the best condition for producing the biosurfactant was determined in assay 4 (3% CG and 5% CSL). The biosurfactant reduced the surface tension of water from 72 to 28.8 mN/m and produced a yield of 1.74 g/L. The preliminary biochemical characterization showed that the biosurfactant consisted of proteins (38.0%), carbohydrates (35.4%), and lipids (5.5%). The compounds presented an anionic character, nontoxicity, and great stability for all conditions tested. The biomolecule displayed great ability in dispersing hydrophobic substrates in water, thereby resulting in 53.4 cm2 ODA. The best efficiency of the biosurfactant in removing the pollutant diesel oil from marine soil was 79.4%. CONCLUSIONS: This study demonstrated the ability of R. arrhizus UCP1607 to produce a low-cost biosurfactant characterized as a glycoprotein and its potential use in the bioremediation of the hydrophobic diesel oil pollutant in marine soil
Assuntos
Rhizopus/metabolismo , Tensoativos/metabolismo , Gasolina , Solo , Tensoativos/toxicidade , Tensão Superficial , Biodegradação Ambiental , Ambiente Marinho , Zea mays , Agroindústria , Interações Hidrofóbicas e Hidrofílicas , Glicerol , Resíduos Industriais , Micelas , Mucorales/metabolismoRESUMO
BACKGROUND: Biosurfactants are surface-active agents produced by microorganisms that have higher efficiency and stability, lower toxicity and higher biocompatibility and biodegradability than chemical surfactants. Despite its properties and potential application in a wide range of environmental and industrial processes, biosurfactants are still not cost-competitive when compared to their synthetic counterparts. Cost effective technologies and renewable raw substrates as agro-industrial and regional waste from northeast of Brazil as cassava flour wastewater, supplemented with lactose and corn oil are mainly the chemically media for growing microorganism and in turn the production of the biosurfactant of quality. This study aimed to obtained biosurfactant by Serratia marcescens UCP 1549 containing cassava flour wastewater (CWW), by application of a full-factorial design, as sustainable practices in puts the production process in promising formulation medium. The characterization of the biomolecule was carried out, as well as the determination of its stability and toxicity for cabbage seeds. In addition, its ability to stimulate seed germination for agriculture application and oil spill bioremediation were investigated. RESULTS: Serratia marcescens showed higher reduction of surface tension (25.92 mN/m) in the new medium containing 0.2% lactose, 6% cassava flour wastewater and 5% corn waste oil, after 72 h of fermentation at 28 °C and 150 rpm. The substrate cassava flour wastewater showed a promising source of nutrients for biosurfactant production. The isolate biosurfactant exhibited a CMC of 1.5% (w/v) and showed an anionic and polymeric structure, confirmed by infrared spectra. The biomolecule demonstrated high stability under different temperatures, salinity and pH values and non-toxicity against to cabbage seeds. Thus, exploring biosurfactant their potential role in seeds germinations and the promotion and agricultural applications was investigated. In addition, the effectiveness of biosurfactant for removal burned motor oil adsorbed in sand was verified. CONCLUSIONS: The use of medium containing CWW not only reduces the cost of process of biosurfactant production, but also the environmental pollution due to the inappropriate disposal of this residue. This fact, added to the high stability and non-toxicity of the biosurfactant produced by S. marcescens UCP 1549, confirms its high environmental compatibility, make it a sustainable biocompound that can be replace chemical surfactants in diverse industries. In addition, the effectiveness of biosurfactant for stimulate seed germination and removing burned motor oil from sand, suggests its suitability for agriculture and bioremediation applications.
Assuntos
Biodegradação Ambiental , Serratia marcescens/metabolismo , Tensoativos/metabolismo , Reatores Biológicos , Brassica/efeitos dos fármacos , Brassica/crescimento & desenvolvimento , Germinação/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Serratia marcescens/química , Serratia marcescens/crescimento & desenvolvimento , Cloreto de Sódio/química , Poluentes do Solo/química , Poluentes do Solo/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Tensão Superficial , Tensoativos/química , Tensoativos/toxicidade , TemperaturaRESUMO
El año 1994 marcó una línea temporal de avance y desarrollo en la investigación de cierto grupo de linfomas, caracterizados por la afectación, generalmente extranodal, en la línea media facial, la nasofaringe y la piel. La Organización Mundial de la Salud, y su más reciente revisión en el 2016, los agrupó dentro del apartado de neoplasias maduras de células T y natural killer como linfomas extraganglionares. Se presenta a una paciente, blanca, de 71 años de edad, con diagnóstico de un linfoma cutáneo de células T/natural killer tipo nasal, angiocéntrico en estadio avanzado. Se trata de un linfoma poco común, pero con curso clínico agresivo, con múltiples factores de mal pronóstico y escasa respuesta al tratamiento, que ocasionó el desenlace fatal de la paciente.
Assuntos
Linfoma Extranodal de Células T-NKRESUMO
Almost all oleaginous microorganisms are available for biodiesel production, and for the mechanism of oil accumulation, which is what makes a microbial approach economically competitive. This study investigated the potential that the yeast Candida lipolytica UCP0988, in an anamorphous state, has to produce simultaneously a bioemulsifier and to accumulate lipids using inexpensive and alternative substrates. Cultivation was carried out using waste soybean oil and corn steep liquor in accordance with 2² experimental designs with 1% inoculums (107 cells/mL). The bioemulsifier was produced in the cell-free metabolic liquid in the late exponential phase (96 h), at Assay 4 (corn steep liquor 5% and waste soybean oil 8%), with 6.704 UEA, IE24 of 96.66%, and showed an anionic profile. The emulsion formed consisted of compact small and stable droplets (size 0.2-5 µm), stable at all temperatures, at pH 2 and 4, and 2% salinity, and showed an ability to remove 93.74% of diesel oil from sand. The displacement oil (ODA) showed 45.34 cm² of dispersion (central point of the factorial design). The biomass obtained from Assay 4 was able to accumulate lipids of 0.425 g/g biomass (corresponding to 42.5%), which consisted of Palmitic acid (28.4%), Stearic acid (7.7%), Oleic acid (42.8%), Linoleic acid (19.0%), and γ-Linolenic acid (2.1%). The results showed the ability of C. lipopytica to produce both bioemulsifier and biodiesel using the metabolic conversion of waste soybean oil and corn steep liquor, which are economic renewable sources.