Bioprospecting the antimicrobial, antibiofilm and antiproliferative activity of Symplocos racemosa Roxb. Bark phytoconstituents along with their biosafety evaluation and detection of antimicrobial components by GC-MS.

BACKGROUND: Plants provide a ray of hope to combat the ever increasing antibiotic resistance and Symplocos racemosa is a valuable medicinal plant. The study focused on highlighting the importance of this plant's phytoconstituents as potential source of novel antimicrobials against planktonic as well as biofilm forming microorganisms, along with their antiproliferative activity. The biosafety of the phytoconstituents was also established, followed by detection of probable antimicrobial components. METHODS: The best organic extractant and major groups of phytoconstituents were tested for their antimicrobial activity against reference microbial strains and drug-resistant clinical isolates. The anti-proliferative potential of the most active group of phytoconstituents was evaluated against cancerous cell lines. The in vitro biosafety of phytoconstituents was evaluated by Ames and MTT assay, while in vivo biosafety of the most active phytoconstituents, i.e., flavonoids was determined by acute oral toxicity. Further, the probable antimicrobial components in the flavonoids were detected by TLC and GC-MS. RESULTS: Ethyl acetate extract was the most effective among various organic extracts, whereas phytoconstituents such as flavonoids, cardiac glycosides, saponins, tannins, triterpenes and phytosterols were the major groups present, with flavonoids being the most potent antimicrobials. The phytoconstituents displayed a significant antibiofilm potential, as exhibited by inhibition of initial cell attachment, disruption of the pre-formed biofilms and reduced metabolic activity of biofilms. The phytoconstituents were significantly active against the drug-resistant strains of E.coli, MRSA and Salmonella spp. Further, flavonoids showed significant cytotoxic effect against the cancerous cell lines but were non-cytotoxic against Vero (normal) cell line. All the test preparations were biosafe, as depicted by the Ames test and MTT assay. Also, flavonoids did not induce any abnormality in body weight, clinical signs, biochemical parameters and organs' histopathology of the Swiss albino mice during in vivo acute oral toxicity studies. The flavonoids were resolved into 4 bands (S1-S4), where S3 was the most active and its GC-MS analysis revealed the presence of a number of compounds, where Bicyclo [2.2.1]heptan-2-one,1,7,7-trimethyl-, (1S)- was the most abundant. CONCLUSIONS: These findings suggest that the phytoconstituents from Symplocos racemosa bark could act as potential source of antimicrobial as well as antiproliferative metabolites.

Odontologia em Tempos de COVID-19: Revisão Integrativa e Proposta de Protocolo para Atendimento nas Unidades de Saúde Bucal da Polícia Militar do Estado do Rio de Janeiro - PMERJ / Dentistry During the COVID-19 Pandemic: Integrative Review and Proposed Protocol for the Rio de Janeiro State Military Police Dental Care Units

Objetivo: sistematizar a produção bibliográfica sobre as recomendações, práticas e cuidados adotados no atendimento odontológico em tempos de COVID-19, assim como, propor um protocolo de atendimento odontológico nas unidades de saúde bucal da Polícia Militar do Estado do Rio de Janeiro a partir das evidências encontradas na literatura. Material e Métodos: foi realizada uma busca bibliográfica no dia 11 de abril de 2020 em bases bibliográficas eletrônicas brasileiras e internacionais (Portal Regional da Biblioteca Virtual em Saúde, Web of Science e Pubmed), a partir da estratégia de busca ("COVID-19" AND "dentistry"), entre estudos publicadas nos anos de 2019 e 2020. Após aplicados os critérios de inclusão e exclusão dos documentos, 18 estudos foram considerados elegíveis para a realização da revisão. Resultados: a partir das evidências científicas encontradas nos estudos, foi construída uma proposta de protocolo para o atendimento odontológico nas unidades de saúde da Polícia Militar do Estado do Rio de Janeiro, assim como em qualquer outra unidade de saúde bucal. Conclusão: durante o período de surto epidêmico os atendimentos devem restringir-se às urgências e emergências odontológicas. O Cirurgião-Dentista deve redobrar a atenção à rotina de biossegurança como: lavagem rigorosa das mãos com água e sabão e/ou 'álcool gel a 70%', uso correto de todo equipamento de proteção individual e sua troca a cada paciente. Recomenda-se o tempo de 3 horas entre os atendimentos quando houver produção de aerossol, a higienização de todas as superfícies do consultório com hipoclorito de sódio a 0,1% ou 'álcool 70%', esterilização de todo instrumental e o descarte adequado dos resíduos.

Objective: to collate the literature that contains recommendations, best practices, and infection control measures for dental health care during the COVID-19 pandemic and, based on this evidence, to propose a protocol for use at the Rio de Janeiro State Military Police dental health care units. Materials and Methods: search of the regional VHL Network Portal, Web of Science, and Pubmed databases using the search query ("covid19" AND "dentistry") to retrieve studies published in 2019 and 2020. After applying the inclusion and exclusion criteria, 18 were found to be eligible for the review. Results: from the scientific evidence reported in the retrieved documents, an infection control protocol was proposed for use at the Rio de Janeiro State Military Police dental care units, which could be applied to any dental health setting. Conclusion: while the epidemic continues, only urgent and emergency dental care should be provided. The dental surgeon should adopt enhanced biosecurity measures, namely: rigorous hand sanitizing with soap and water and/or 70% alcohol hand sanitizer; correct use of complete personal protective equipment (PPE), and discarding of PPE after each patient; allowing three hours to elapse between patients after aerosol-generating procedures; cleaning of all surfaces with 0.1% sodium hypochlorite or 70% ethanol; sterilization of all instruments; and adequate disposal of all waste.

Abordando la problemática de las armas biológicas en el siglo XXI: el papel de una red de prevención 2.0 / No disponible

El uso estratégico de la enfermedad en la guerra ha demostrado ser una amenaza para la humanidad desde hace mucho tiempo; sin embargo, la naturaleza cambiante tanto de la ciencia como de Ia seguridad tiene, al combinarse, el potencial idóneo para estimular la adopción de nuevas (y clásicas) armas biológicas. Este breve artículo se inicia con la descripcion de algunos de estos cambios antes de considerar los medios y las medidas establecidas para hacer frente al desafío de las armas biológicas. Posteriormente, se procederá a delinear una red de prevención 2.0, compuesta por hebras que se refuerzan mutuamente, con la que se pretende formar un marco para un enfoque más holistico que sirva para hacer frente al desafío de las armas biológicas en el siglo XXI (AU)

The strategic use of disease in Warfare has long proven a menace to humankind; however, the changing nature of both science and security has the potential to encourage the assimilation of new (and old) biological weapons. This short article begins by outlining some of these changes before considering the means and measures in place to deal with the challenge of biological weapons. It proceeds to outline a Web of Prevention 2.0, comprised of mutually reinforcing strands that are intended to form a framework for a more holistic approach to dealing with the challenge of biological Weapons around the globe ln the 21st century (AU)

Development of a high-throughput replicon assay for the identification of respiratory syncytial virus inhibitors.

Respiratory syncytial virus (RSV) drug discovery has been hindered by the lack of good chemistry starting points and would benefit from robust and convenient assays for high-throughput screening (HTS). In this paper, we present the development and optimization of a 384-well RSV replicon assay that enabled HTS for RSV replication inhibitors with a low bio-containment requirement. The established replicon assay was successfully implemented for high-throughput screening. A validation screen was performed which demonstrated high assay performance and reproducibility. Assay quality was further confirmed via demonstration of appropriate pharmacology for different classes of RSV replication tool inhibitors. RSV replicon and cytotoxicity assays were further developed into a multiplexed format that measured both inhibition of viral replication and cytotoxicity from the same well. This provided a time and cost efficient approach to support lead optimization. In summary, we have developed a robust RSV replicon assay to help expedite the discovery of novel RSV therapeutics.

Keeping the genie in the bottle: transgene biocontainment by excision in pollen.

Gene flow from transgenic plants is an environmental and regulatory concern. While biocontainment might be achieved using male sterility or transgenic mitigation tools, we believe that perhaps the optimal solution might be simply to remove transgenes from pollen. Male sterility might not be ideal for many pollinators, and might not be implementable using standardized genes. Transgenic mitigation might not be useful to control conspecific gene flow (e.g. crop to crop), and relies on competition and not biocontainment per se. Site-specific recombination systems could allow highly efficient excision of transgenes in pollen to eliminate, or at least minimize, unwanted transgene movement via pollen dispersal. There are other potential biotechnologies, such as zinc finger nucleases, that could be also used for transgene excision.

Evaluating biological containment strategies for pollen-mediated gene flow.

Several biological containment methods have been developed to reduce pollen dispersal; many of them only have a proof of concept in a model plant species. This review focuses on biological containment measures which were tested for their long-term efficiency at the greenhouse or field scale level, i.e. plastid transformation, transgene excission, cleistogamy and cytoplasmic male sterility (CMS). Pollen-mediated gene transfer in transplastomic tobacco could occur at very low frequencies if the predominant mode of inheritance is maternal. Transgene excision from tobacco pollen can be made highly efficient by coexpression of two recombinases. For cleistogamous oilseed rape it was shown that some flowers were partially open depending on genotypes, environment and recording dates. Reports on the stability of CMS in maize and sunflower indicated that there is a high variability for different genotypes under different environmental conditions and over successive years. But for both crop types some stable lines could be selected. These data demonstrate that the biological containment methods discussed are very promising for reducing gene flow but that no single containment strategy provides 100% reduction. However, the necessary efficiency of biological containment methods depends on the level of containment required. The containment level may need to be higher for safety purposes (e.g. production of special plant-made pharmaceuticals), while much lower containment levels may already be sufficient to reach coexistence goals. It is concluded that where pollen-mediated gene flow must be prevented altogether, combinations of complementary containment systems will be required.

Organically modified low-grade kaolin as a secondary containment material for underground storage tanks.

Batch scale reactions were conducted to evaluate the efficacy of modified low-grade kaolin for the treatment of petroleum contaminants. Low-grade kaolin, which has been unvalued as material in the mining process because of its low quality for commercial products, was modified with HDTMA (hexadecyl-trimethylammonium), and its efficiency was compared with that of HDTMA-modified bentonite, which is used as a secondary containment barrier for underground storage tanks. The sorption capacity and hydraulic conductivity of both the HDTMA-modified bentonite and low-grade kaolin were investigated and showed distribution coefficients in the sorption of benzene, toluene, ethylbenzene and xylene ranging between 45.7 and 583.7 and 57.0 and 525.1, respectively. The hydraulic conductivities were 2.53 x 10(-8) and 5.62 x 10(-8) cm/s for the HDTMA-modified bentonite and low-grade kaolin, respectively. These results suggest that HDTMA-modified low-grade kaolin could be used as a hydraulic barrier against advection migration of petroleum contaminants. Simulation of the one-dimensional transport of benzene through a liner made of either one of the compounds was also performed. These results also showed that HDTMA-modified kaolin more effectively retards the transport of benzene.

Dual system to reinforce biological containment of recombinant bacteria designed for rhizoremediation.

Active biological containment (ABC) systems have been designed to control at will the survival or death of a bacterial population. These systems are based on the use of a killing gene, e.g., a porin-inducing protein such as the one encoded by the Escherichia coli gef gene, and a regulatory circuit that controls expression of the killing gene in response to the presence or absence of environmental signals. An ABC system for recombinant microorganisms that degrade a model pollutant was designed on the basis of the Pseudomonas putida TOL plasmid meta-cleavage regulatory circuit. The system consists of a fusion of the Pm promoter to lacI, whose expression is controlled by XylS with 3-methylbenzoate, and a fusion of a synthetic P(lac) promoter to gef. In the presence of the model pollutant, bacterial cells survived and degraded the target compound, whereas in the absence of the aromatic carboxylic acid cell death was induced. The system had two main drawbacks: (i) the slow death of the bacterial cells in soil versus the fast killing rate in liquid cultures in laboratory assays, and (ii) the appearance of mutants, at a rate of about 10(-8) per cell and generation, that did not die after the pollutant had been exhausted. We reinforced the ABC system by including it in a Deltaasd P. putida background. A P. putida Deltaasd mutant is viable only in complex medium supplemented with diaminopimelic acid, methionine, lysine, and threonine. We constructed a P. putida Deltaasd strain, called MCR7, with a Pm::asd fusion in the host chromosome. This strain was viable in the presence of 3-methylbenzoate because synthesis of the essential metabolites was achieved through XylS-dependent induction. In the P. putida MCR7 strain, an ABC system (Pm::lacI, xylS, P(lac)::gef) was incorporated into the host chromosome to yield strain MCR8. The number of MCR8 mutants that escaped killing was below our detection limit (<10(-9) mutants per cell and generation). The MCR8 strain survived and colonized rhizosphere soil with 3-methylbenzoate at a level similar to that of the wild-type strain. However, it disappeared in less than 20 to 25 days in soils without the pollutant, whereas an asd(+), biologically contained counterpart such as P. putida CMC4 was still detectable in soils after 100 days.

The effect of different oil spill remediation techniques on petroleum hydrocarbon elimination in Australian bass (Macquaria novemaculeata).

Petroleum hydrocarbons were investigated in juvenile Australian bass, Macquaria novemaculeata, following exposure to the water accommodated fraction (WAF) of Bass Strait crude oil, chemically dispersed crude oil, and burnt crude oil. Each treatment was administered for 16 days either through the water column or through the diet (amphipod, Allorchestes compressa). Polycyclic aromatic hydrocarbon (PAH) elimination was determined by measuring biliary benzo(a)pyrene (B(a)P) and naphthalene-type metabolites. Biliary PAH-type metabolite concentrations varied with the type of oil spill remediation technique, route of exposure (food versus water), and exposure concentration. Fish exposed to chemically dispersed crude oil via the water exhibited the highest PAH-type biliary metabolite concentrations, relative to fish exposed to other treatments. In fish exposed via the diet, the highest concentration of both types of biliary metabolites also appeared in the dispersed oil-exposed individuals. The results suggest that chemically dispersing oil may have the greatest effect on bioavailability of hydrocarbons, both through waterborne and food chain exposures.