ß-lactams resistance gene quantification in an antibiotic resistant Escherichia coli water suspension treated by advanced oxidation with UV/H2O2.

Water is one of the most important habitats and route for the spread of antibiotic resistance (AR) in the environment and disinfection processes can be a potential barrier to minimise this risk. In this study the effect of UV/H2O2 process on the potential of AR transfer was investigated through cultivation methods vs (polymerase chain reaction) PCR based methods. blaTEM was selected as target antibiotic resistance gene (ARG) and was quantified by qPCR in the survived colonies and the whole suspension (total DNA). The detection limit of residual antibiotic resistant Escherichia coli (E. coli) colonies (5CFUmL-1) was reached after 240min treatment, but blaTEM gene was still present in total DNA after 300min (2.8×106 copies mL-1), and no effect was observed in DNA extracted from cell cultures (3.8×108 copies mL-1 after 90min). Accordingly, the investigated disinfection process may select for unaffected ARGs, therefore contributing to the potential transfer of AR in the environment.

Abordagem de cicatrizes por queimaduras com microagulhamento: revisão da literatura / Microneedling approach in burn scars: literature review / Abordaje con microagujas en la cicatrices por quemaduras: revisión de la literatura

Introdução: Queimaduras são feridas traumáticas causadas por agentes térmicos, químicos, elétricos ou radioativos. Há na literatura diversos estudos que discorrem sobre técnicas que amenizem as sequelas deixadas pelas queimaduras. Dentro dos tratamentos disponíveis, o microagulhamento tem se apresentado como estratégia de importantes resultados. O princípio do microagulhamento é proporcionar um estímulo na produção de colágeno, melhorar a qualidade da cicatriz e construção do tecido cicatricial ao nível da pele normal, preservando a epiderme e modulando os níveis de fatores de crescimento de transformação ß1 e 2, que são considerados pró-inflamatórios, e aumentando os níveis de TGFß 3, reorganizando as fibras colágenas e normalizando o aspecto do tecido, sugerindo uma melhora em cicatrizes fibróticas. Objetivo: Identificar, na literatura, a ação do microagulhamento no tratamento de cicatrizes de pacientes que sofreram queimaduras. Método: O método adotado para a pesquisa foi a revisão do tipo descritiva, com estratégia de busca elaborada, utilizando artigos indexados nas bases de dados LILACS, SciELO, PubMed e Medline no período de 2008 a 2016. Resultados: Foram encontrados sete estudos, sendo selecionados quatro que preencheram os critérios de inclusão. Dentre os selecionados, dois são estudos de caso, uma revisão bibliográfica sobre a técnica, porém não relacionada especificamente a cicatrizes por queimaduras, e um ensaio clínico randomizado. Conclusão: O microagulhamento se mostra como um promissor tratamento nas cicatrizes de queimadura, promovendo melhora do aspecto estético. Ainda há carência de estudos sobre a temática, especialmente os ensaios clínicos randomizados. Recomenda-se que mais estudos nesse padrão sejam realizados.

Introduction: Burns are traumatic wounds caused by thermal, chemical, electrical or radioactive agents. In the literature there are several studies that discuss techniques that mitigate the consequences left by the burns. Among the treatments available, the microneedling has emerged as important strategy results. The principle of microneedling is to provide a stimulation of collagen production, improving scar quality and construction of scar tissue at the level of the normal skin, preserving the epidermis modulating levels ß1 and 2, transforming growth factors that are considered pro-inflammatory, and increasing levels of TGFß 3 reorganizing collagen fibers, and normalizing the appearance of tissue, suggesting an improvement in fibrotic scars. Objective: To identify, in the literature, the action of microneedling in treating scars of patients who suffered burns. Method: The method adopted for the research was a review of descriptive, with elaborate search strategy using articles indexed in the databases LILACS, SciELO, PubMed and Medline from 2008 to 2016. Results: Seven studies were found, and selected four that met the inclusion criteria. Among the selected, two are case studies, a literature review on the technical but not specifically related to scarring from burns and a randomized clinical trial. Conclusion: Microneedling shown as a promising treatment in burn scars, promoting improved aesthetic appearance. There is still a lack of studies on the subject especially randomized clinical trials, so it is recommended that further studies in this standard are met.

Introducción: Las quemaduras son heridas traumáticas causadas por agentes térmicos, químicos, eléctricos o radioactivos. En la literatura varios estudios que tratan sobre las técnicas que mitiguen las consecuencias dejadas por las quemaduras. Entre los tratamientos disponibles, las microagujas han presentado una estrategia con resultados importantes. El principio de microagujas es proporcionar una estimulación de la producción de colágeno, mejorando la calidad de la cicatriz y la construcción de tejido de la cicatriz en el nivel de la piel normal, preservando la epidermis modulación de los niveles ß1e2 factores de crecimiento transformante que se consideran pro-inflamatoria, y aumentar niveles de TGF 3 reorganización de las fibras de colágeno normalizar la apariencia de tejido que sugiere una mejora de cicatrices fibróticas. Objetivo: Identificar, en la literatura, la acción de microagujas en el tratamiento de cicatrices de pacientes que sufrieron quemaduras. Método: El método adoptado para la investigación fue una revisión descriptiva, con estrategia de búsqueda elaborada, utilizando artículos indexados en las bases de datos LILACS, SciELO, PubMed y Medline desde 2008 hasta 2016. Resultados: Fueron encontrados siete artículos, entre los cuales se seleccionaron cuatro que cumplían los criterios de inclusión. Entre los seleccionados, dos son estudios de casos, una revisión de la literatura en la técnica, pero no específicamente relacionadas con la cicatrización de quemaduras y un ensayo clínico aleatorizado. Conclusión: Microagujas se muestra como un tratamiento prometedor en las cicatrices de quemaduras, promoviendo una mejor apariencia estética. Todavía hay una falta de estudios sobre el tema ensayos clínicos aleatorizados sobre todo, se recomienda que se cumplan otros estudios en esta norma.

Antibiotic resistance spread potential in urban wastewater effluents disinfected by UV/H2O2 process.

Urban wastewater treatment plants (UWTPs) are among the main hotspots of antibiotic resistance (AR) spread into the environment and the role of conventional and new disinfection processes as possible barrier to minimise the risk for AR transfer is presently under investigation. Accordingly, the aim of this work was to evaluate the effect of an advanced oxidation process (AOP) (specifically UV/H2O2) on AR transfer potential. UV/H2O2 disinfection experiments were carried out on real wastewater samples to evaluate the: i) inactivation of total coliforms, Escherichia coli and antibiotic resistant E. coli as well as ii) possible removal of target antibiotic resistance genes (ARGs) (namely, blaTEM, qnrS and tetW). In particular, DNA was extracted from both antibiotic resistant E. coli bacterial cells (intracellular DNA), grown on selective culture media, and the whole water suspension (total DNA) collected at different treatment times. Polymerase chain reaction (PCR) assay was performed to detect the absence/presence of the selected ARGs. Real Time quantitative Polymerase Chain Reaction (qPCR) was used to quantify the investigated ARGs in terms of copiesmL(-1). In spite of the bacterial inactivation and a decrease of ARGs in intracellular DNA after 60min treatment, UV/H2O2 process was not effective in ARGs removal from water suspension (total DNA). Particularly, an increase up to 3.7×10(3)copiesmL(-1) (p>0.05) of blaTEM gene was observed in total DNA after 240min treatment, while no difference (p>0.05) was found for qnrS gene between the initial (5.1×10(4)copiesmL(-1)) and the final sample (4.3×10(4)copiesmL(-1)). On the base of the achieved results, the investigated disinfection process may not be effective in minimising AR spread potential into the environment. The death of bacterial cells, which results in DNA release in the treated water, may pose a risk for AR transfer to other bacteria present in the receiving water body.

Cross-Contamination of Residual Emerging Contaminants and Antibiotic Resistant Bacteria in Lettuce Crops and Soil Irrigated with Wastewater Treated by Sunlight/H2O2.

The sunlight/H2O2 process has recently been considered as a sustainable alternative option compared to other solar driven advanced oxidation processes (AOPs) in advanced treatment of municipal wastewater (WW) to be reused for crop irrigation. Accordingly, in this study sunlight/H2O2 was used as disinfection/oxidation treatment for urban WW treatment plant effluent in a compound parabolic collector photoreactor to assess subsequent cross-contamination of lettuce and soil by contaminants of emerging concern (CECs) (determined by QuEChERS extraction and LC-QqLIT-MS/MS analysis) and antibiotic resistant (AR) bacteria after irrigation with treated WW. Three CECs (carbamazepine (CBZ), flumequine (FLU), and thiabendazole (TBZ) at 100 µg L(-1)) and two AR bacterial strains (E. coli and E. faecalis, at 10(5) CFU mL(-1)) were spiked in real WW. A detection limit (DL) of 2 CFU mL(-1) was reached after 120 min of solar exposure for AR E. coli, while AR E. faecalis was more resistant to the disinfection process (240 min to reach DL). CBZ and TBZ were poorly removed after 90 min (12% and 50%, respectively) compared to FLU (94%). Lettuce was irrigated with treated WW for 5 weeks. CBZ and TBZ were accumulated in soil up to 472 ng g(-1) and 256 ng g(-1) and up-taken by lettuce up to 109 and 18 ng g(-1), respectively, when 90 min treated WW was used for irrigation; whereas no bacteria contamination was observed when the bacterial density in treated WW was below the DL. A proper treatment time (>90 min) should be guaranteed in order to avoid the transfer of pathogens from disinfected WW to irrigated crops and soil.

Inactivation and regrowth of multidrug resistant bacteria in urban wastewater after disinfection by solar-driven and chlorination processes.

Solar disinfection and solar-driven advanced oxidation processes (AOPs) (namely H2O2/sunlight, TiO2/sunlight, H2O2/TiO2/sunlight, solar photo-Fenton) were evaluated in the inactivation of indigenous antibiotic-resistant bacteria (ARB) in real urban wastewater. A multidrug resistant (MDR) Escherichia coli strain isolated from the effluent of the biological process of an urban wastewater treatment plant was the target ARB. The higher inactivation rates (residual density under detection limit, 2 CFUm L(-1)) were achieved with H2O2/TiO2/sunlight (cumulative energy per unit of volume (QUV) in the range 3-5 kJ L(-1), depending on H2O2/TiO2 ratio) and H2O2/sunlight (QUV of 8 kJ L(-1)) processes. All investigated processes did not affect antibiotic resistance of survived colonies. Moreover, H2O2/sunlight was compared with conventional chlorination process to evaluate bacterial regrowth potential and particularly the proportion of indigenous MDR E. coli with respect to total indigenous E. coli population. Chlorination (1.0 mg Cl2 L(-1)) was more effective than H2O2/sunlight (50 mg H2O2 L(-1)) to achieve total inactivation of MDR E. coli (15 min Vs 90 min) but less effective in controlling their regrowth (24 h Vs 48 h). Interestingly, the percentage of MDR E. coli in H2O2/sunlight treated samples decreased as incubation time increased; the opposite was observed for chlorinated samples.

Vancomycin resistant enterococci: from the hospital effluent to the urban wastewater treatment plant.

Vancomycin is an important antibiotic to treat serious nosocomial enterococci infections. Human activities, in particular those related with clinical practices performed in hospitals, can potentiate the transfer and selection of clinically-relevant resistant bacteria such as vancomycin resistant enterococci (VRE). Indeed, previous studies demonstrated the occurrence of VRE in urban wastewater treatment plants and related environments (e.g. sewage, rivers). In this study, the occurrence of VRE in a hospital effluent and in the receiving urban wastewater treatment plant was investigated. Vancomycin and ciprofloxacin resistant bacteria occurred in the hospital effluent and in raw municipal inflow at densities of 10(3) to 10(2) CFU mL(-1), being significantly more prevalent in the hospital effluent than in the urban wastewater. Most of the VRE isolated from the hospital effluent belonged to the species Enterococcus faecalis and Enterococcus faecium and presented multidrug-resistance phenotypes to ciprofloxacin, tetracycline, erythromycin, and high-level gentamicin. The same pattern was observed in clinical isolates and in enterococci isolated from the final effluent of the urban wastewater treatment plant. These results show that hospital effluents discharged into urban wastewater treatment plants may be a relevant source of resistance spread to the environment.