Antibiofilm activity of bromelain from pineapple against Staphylococcus aureus

Bromelain is a set of proteolytic enzymes usually obtained from pineapple (Ananas comosus). Although bromelain has distinguished therapeutic properties, little is known about its proteolytic potential against opportunistic pathogens related to wound healing complications, such as Staphylococcus aureus. This study aimed toinvestigate the antibiofilm and antibacterial activity of bromelain in 43 clinical strains of S. aureusisolated from chronic wounds and blood cultures. Bromelain's activity against S. aureusbiofilm in vitrowas assessed by analyzing biofilm formation in cultures grownin the presence of 1% bromelain and biofilm destruction after the addition of 1% bromelain to mature biofilms. Proteinase K and sodium metaperiodate were also added to mature biofilms in parallel to compare their activity with that of bromelain and, together with exopolysaccharide and protein production rate assays, to determine the chemical composition of the biofilm extracellular matrix of selected strains of S. aureus. Bromelain was also evaluated for its DNase activity and impact on cellular hydrophobicity and auto-aggregation. Mueller-Hinton agar dilution was used to determine bromelain minimal inhibitory concentration (MIC). Biofilm assays showed that 1% bromelain significantly inhibits S. aureusbiofilm formation (p= 0.0157) by up to 4-fold and destroys its mature biofilms (p < 0.0001) by up to 6.4-fold, both compared to the control grown without bromelain. Biofilms of methicillin-resistant S. aureusstrains isolated from chronic wounds were the most affected by bromelain treatment. No antibacterial activity was detected with bromelain MIC assays and the proteolytic activity of bromelain was identified as the main antibiofilm mechanism of the enzyme, though its DNase activity may also contribute. The epithelial therapeutic properties of bromelain combined with its antibiofilm activity against S. aureusmake it a promising alternative to compose the therapeutic arsenal for the control of S. aureusbiofilms in the context of wound care.(AU)

Exopolysaccharyde production by Cryptococcus laurentii SD7 using molasses and corn steep liquor as substrates

Microbial polysaccharides are of great biotechnological and commercial interest and have wide application in the food, cosmetic and medicine industries. Exopolysaccharide (EPS) production by the yeast Cryptococcus laurentii SD7, isolated from fresh water molluscs, was studied using agro-industrial byproducts as substrates in the submerged fermentation. The Central Composite Design (CCD) 23 was used to study the influence of pH, different concentrations on sugarcane molasses and corn steep liquor (CSL), for 48 hours. According to the results, the highest EPS production occurred at the initial pH 5 and at 8.4% concentration of sugarcane molasses, which were statistically significant variable at 10% (p < 0.1). The concentration of CSL had no influence in the studied range, thus, it can be used lowest concentration (0.3%). The time course of EPS production showed that while cell growth peaked within 48 hours, the highest EPS production (6.61 g L-1) occurred at 168 hours, with a productivity of about 0.04 g L-1 h-1. The pH of the medium remained approximately constant throughout the fermentation process. The yeast C. laurentii SD7 showed great potential for EPS production at a low cost and with sustainable substrates.(AU)

Exopolysaccharyde production by Cryptococcus laurentii SD7 using molasses and corn steep liquor as substrates / Exopolysaccharyde production by Cryptococcus laurentii SD7 using molasses and corn steep liquor as substrates

Microbial polysaccharides are of great biotechnological and commercial interest and have wide application in the food, cosmetic and medicine industries. Exopolysaccharide (EPS) production by the yeast Cryptococcus laurentii SD7, isolated from fresh water molluscs, was studied using agro-industrial byproducts as substrates in the submerged fermentation. The Central Composite Design (CCD) 23 was used to study the influence of pH, different concentrations on sugarcane molasses and corn steep liquor (CSL), for 48 hours. According to the results, the highest EPS production occurred at the initial pH 5 and at 8.4% concentration of sugarcane molasses, which were statistically significant variable at 10% (p < 0.1). The concentration of CSL had no influence in the studied range, thus, it can be used lowest concentration (0.3%). The time course of EPS production showed that while cell growth peaked within 48 hours, the highest EPS production (6.61 g L-1) occurred at 168 hours, with a productivity of about 0.04 g L-1 h-1. The pH of the medium remained approximately constant throughout the fermentation process. The yeast C. laurentii SD7 showed great potential for EPS production at a low cost and with sustainable substrates.

Microbial polysaccharides are of great biotechnological and commercial interest and have wide application in the food, cosmetic and medicine industries. Exopolysaccharide (EPS) production by the yeast Cryptococcus laurentii SD7, isolated from fresh water molluscs, was studied using agro-industrial byproducts as substrates in the submerged fermentation. The Central Composite Design (CCD) 23 was used to study the influence of pH, different concentrations on sugarcane molasses and corn steep liquor (CSL), for 48 hours. According to the results, the highest EPS production occurred at the initial pH 5 and at 8.4% concentration of sugarcane molasses, which were statistically significant variable at 10% (p < 0.1). The concentration of CSL had no influence in the studied range, thus, it can be used lowest concentration (0.3%). The time course of EPS production showed that while cell growth peaked within 48 hours, the highest EPS production (6.61 g L-1) occurred at 168 hours, with a productivity of about 0.04 g L-1 h-1. The pH of the medium remained approximately constant throughout the fermentation process. The yeast C. laurentii SD7 showed great potential for EPS production at a low cost and with sustainable substrates.

Exopolysaccharide production from Bacillus velezensis KY471306 using statistical experimental design

Exopolysaccharide (EPS) biopolymers produced by microorganisms play a crucial role in the environment such as health and bio-nanotechnology sectors, gelling agents in food and cosmetic industries in addition to bio-flocculants in the environmental sector as they are degradable, nontoxic. This study focuses on the improvement of EPS production through manipulation of different culture and environmental conditions using response surface methodology (RSM). Plackett-Burman design indicated that; molasses, yeast extract and incubation temperature are the most effective parameters. Box-Behnken RSM indicated that; the optimum concentration for each parameter was 12% (w/v) for molasses, 6 g/L yeast extract and 30 °C for incubation temperature. The most potent bacterial isolate was identified as Bacillus velezensis KY498625. After production, EPS was extracted, purified using DEAE-cellulose, identified using Fourier transform infrared (FTIR), gel permeation chromatography (GPC) and gas chromatography-mass spectroscopy (GC-MS). The result indicated that; it has molecular weight 1.14 × 105 D consisting of glucose, mannose and galactose.(AU)

Bacterial cellulose to reinforce urethrovesical anastomosis. A translational study

Purpose: To evaluate the efficacy of the cellulosic exopolysaccharide membrane (CEM) as a urethral reinforcement for urethrovesical anastomosis. Methods: Twenty eight rabbits were submitted to urethrovesical anastomosis with or without CEM reinforcement. The animals were divided into 4 groups: C7, CEM7, C14 and CEM14: (C= only anastomosis or CEM = anastomosis + CEM), evaluated after 7 weeks, and 14 weeks. The biointegration and biocompatibility of CEM were evaluated according to stenosis, fistula, urethral wall thickness, urethral epithelium, rate of inflammation and vascularization. Results: Between the two experimental groups, the difference in the number of stenosis or urinary fistula was not statistically significant. The morphometric analysis revealed preservation of urethral lumen, well adhered CEM without extrusion, a controlled inflammatory process and implant vascularization. The urothelium height remained constant over time after CEM reinforcement and the membrane wall was thicker, statistically, after 14 weeks. Conclusion: The absence of extrusion, stenosis or urinary fistula after 14 weeks of urethrovesical anastomosis demonstrates cellulosic exopolysaccharide membrane biocompatibility and biointegration with tendency to a thicker wall.(AU)

Características e propriedades do Kefir / Characteristics and properties of Kefir / Características y propiedades del Kéfir

Pode-se definir kefir como sendo um complexo produto lácteo fermentado produzido por fermentação do leite por bactérias ácido láticas e leveduras contidos dentro de um complexo de exopolissacarídeo e proteínas denominado de grão de kefir. Embora não seja tão popular mundialmente como outros produtos lácteos fermentados ele tem apresentado nos últimos anos um aumento de consumo devido, principalmente, ao seu conteúdo de bactérias probióticas e seus benefícios à saúde. O objetivo desse trabalho foi apresentar as principais características e propriedades do kefir e os benefícios de seu consumo. A composição de microrganismos nos grãos de kefir é muito variável e complexa, uma vez que depende da sua origem, condições de crescimento e manutenção, mas sabe-se que há a predominância de bactérias ácido-láticas, acéticas, leveduras e fungos. O principal polissacarídeo encontrado nos grãos de kefir é o kefirano, um heteropolissacarídeo composto por iguais proporções de glicose e galactose e que possui propriedades antitumorais, antifúngicas, antibacteriana, anti-inflamatória e antioxidante. Devido a essas características, muitos produtos estão sendo desenvolvidos empregando kefir como cultura lática, como queijos, labneh, bebidas à base de extrato de soja e chás fermentados. O uso do kefir como um alimento funcional está aumentando dia a dia em todo o mundo e, assim tendo um maior interesse da comunidade científica por se tratar de um alimento funcional de baixo custo, mas também com várias aplicações na indústria de alimentos sendo desenvolvidas.(AU)

Kefir can be defined as a complex fermented dairy product produced by fermentation of milk by lactic acid bacteria and yeasts contained within a exopolysaccharide and protein complex known as kefir grain. Although it is not as popular worldwide as other fermented dairy products, its consumption has increased in recent years, mainly due to its probiotic bacteria and the health benefits it provides. This work aims at describing the main characteristics and properties of kefir as well as the benefits of its consumption. The microorganism composition in kefir grains is very variable and complex, since it depends on their origin, growth and maintenance conditions, but it is known to present predominantly lactic and acetic acid, as well as yeast and fungal bacteria. The main polysaccharide found in kefir grains is known as kefiran, a heteropolysaccharide comprised of equal proportions of glucose and galactose. It presents antitumor, antifungal, antibacterial, anti-inflammatory and anti-oxidant properties. Due to these characteristics, many products are being developed using kefir as lactic acid culture, such as cheeses, labneh, soy-based drinks and fermented teas. The use of kefir as functional food is increasing worldwide, and therefore, there is a great interest of the scientific community due to it not only being a functional, low-cost food, but also due to several applications in the food industry being developed with it.(AU)

Se puede definir kéfir como un complejo producto lácteo fermentado producido por fermentación de la leche por bacterias ácidos lácticos y levaduras contenidas dentro de un complejo de exopolisacárido y proteínas denominado de grano de kéfir. Aunque no es tan popular mundialmente como otros productos lácteos fermentados, ha presentado en los últimos años un aumento de consumo debido principalmente a su contenido de bacterias probióticas y sus beneficios a la salud que proviene. El objetivo de este estudio fue presentar las principales características y propiedades del kéfir y los beneficios de su consumo. La composición de microorganismos en los granos de kéfir es muy variable y compleja, ya que depende de su origen, condiciones de crecimiento y mantenimiento, pero se sabe que hay predominio de bacterias ácidos lácticos, acéticos, levaduras y hongos. El principal polisacárido encontrado en los granos de kéfir es el kefirano, un heteropolisacárido compuesto por iguales proporciones de glucosa y galactosa y que tiene propiedades antitumorales, anti fúngicas, antibacterianas, antiinflamatorias y antioxidantes. Debido a esas características, muchos productos están siendo desarrollados empleando kéfir como cultura láctica, como quesos, labneh, bebidas a base de extracto de soja y tés fermentados. El uso del kéfir como alimento funcional está aumentando día a día en todo el mundo y así teniendo un mayor interés de la comunidad científica por tratarse de un alimento funcional de bajo costo, así como varias aplicaciones en la industria de alimentos están siendo desarrolladas.(AU)

Características e propriedades do Kefir / Characteristics and properties of Kefir / Características y propiedades del Kéfir

Pode-se definir kefir como sendo um complexo produto lácteo fermentado produzido por fermentação do leite por bactérias ácido láticas e leveduras contidos dentro de um complexo de exopolissacarídeo e proteínas denominado de grão de kefir. Embora não seja tão popular mundialmente como outros produtos lácteos fermentados ele tem apresentado nos últimos anos um aumento de consumo devido, principalmente, ao seu conteúdo de bactérias probióticas e seus benefícios à saúde. O objetivo desse trabalho foi apresentar as principais características e propriedades do kefir e os benefícios de seu consumo. A composição de microrganismos nos grãos de kefir é muito variável e complexa, uma vez que depende da sua origem, condições de crescimento e manutenção, mas sabe-se que há a predominância de bactérias ácido-láticas, acéticas, leveduras e fungos. O principal polissacarídeo encontrado nos grãos de kefir é o kefirano, um heteropolissacarídeo composto por iguais proporções de glicose e galactose e que possui propriedades antitumorais, antifúngicas, antibacteriana, anti-inflamatória e antioxidante. Devido a essas características, muitos produtos estão sendo desenvolvidos empregando kefir como cultura lática, como queijos, labneh, bebidas à base de extrato de soja e chás fermentados. O uso do kefir como um alimento funcional está aumentando dia a dia em todo o mundo e, assim tendo um maior interesse da comunidade científica por se tratar de um alimento funcional de baixo custo, mas também com várias aplicações na indústria de alimentos sendo desenvolvidas.(AU)

Kefir can be defined as a complex fermented dairy product produced by fermentation of milk by lactic acid bacteria and yeasts contained within a exopolysaccharide and protein complex known as kefir grain. Although it is not as popular worldwide as other fermented dairy products, its consumption has increased in recent years, mainly due to its probiotic bacteria and the health benefits it provides. This work aims at describing the main characteristics and properties of kefir as well as the benefits of its consumption. The microorganism composition in kefir grains is very variable and complex, since it depends on their origin, growth and maintenance conditions, but it is known to present predominantly lactic and acetic acid, as well as yeast and fungal bacteria. The main polysaccharide found in kefir grains is known as kefiran, a heteropolysaccharide comprised of equal proportions of glucose and galactose. It presents antitumor, antifungal, antibacterial, anti-inflammatory and anti-oxidant properties. Due to these characteristics, many products are being developed using kefir as lactic acid culture, such as cheeses, labneh, soy-based drinks and fermented teas. The use of kefir as functional food is increasing worldwide, and therefore, there is a great interest of the scientific community due to it not only being a functional, low-cost food, but also due to several applications in the food industry being developed with it.(AU)

Se puede definir kéfir como un complejo producto lácteo fermentado producido por fermentación de la leche por bacterias ácidos lácticos y levaduras contenidas dentro de un complejo de exopolisacárido y proteínas denominado de grano de kéfir. Aunque no es tan popular mundialmente como otros productos lácteos fermentados, ha presentado en los últimos años un aumento de consumo debido principalmente a su contenido de bacterias probióticas y sus beneficios a la salud que proviene. El objetivo de este estudio fue presentar las principales características y propiedades del kéfir y los beneficios de su consumo. La composición de microorganismos en los granos de kéfir es muy variable y compleja, ya que depende de su origen, condiciones de crecimiento y mantenimiento, pero se sabe que hay predominio de bacterias ácidos lácticos, acéticos, levaduras y hongos. El principal polisacárido encontrado en los granos de kéfir es el kefirano, un heteropolisacárido compuesto por iguales proporciones de glucosa y galactosa y que tiene propiedades antitumorales, anti fúngicas, antibacterianas, antiinflamatorias y antioxidantes. Debido a esas características, muchos productos están siendo desarrollados empleando kéfir como cultura láctica, como quesos, labneh, bebidas a base de extracto de soja y tés fermentados. El uso del kéfir como alimento funcional está aumentando día a día en todo el mundo y así teniendo un mayor interés de la comunidad científica por tratarse de un alimento funcional de bajo costo, así como varias aplicaciones en la industria de alimentos están siendo desarrolladas.(AU)

Efficient production of pullulan by Aureobasidium pullulans grown on mixtures of potato starch hydrolysate and sucrose

Pullulan is a natural exopolysaccharide with many useful characteristics. However, pullulan is more costly than other exopolysaccharides, which limits its effective application. The purpose of this study was to adopt a novel mixed-sugar strategy for maximizing pullulan production, mainly using potato starch hydrolysate as a low-cost substrate for liquid-state fermentation by Aureobasidium pullulans. Based on fermentation kinetics evaluation of pullulan production by A. pullulans 201253, the pullulan production rate of A. pullulans with mixtures of potato starch hydrolysate and sucrose (potato starch hydrolysate:sucrose = 80:20) was 0.212 h-¹, which was significantly higher than those of potato starch hydrolysate alone (0.146 h-¹) and mixtures of potato starch hydrolysate, glucose, and fructose (potato starch hydrolysate:glucose:fructose = 80:10:10, 0.166 h-¹) with 100 g L-¹ total carbon source. The results suggest that mixtures of potato starch hydrolysate and sucrose could promote pullulan synthesis and possibly that a small amount of sucrose stimulated the enzyme responsible for pullulan synthesis and promoted effective potato starch hydrolysate conversion effectively. Thus, mixed sugars in potato starch hydrolysate and sucrose fermentation might be a promising alternative for the economical production of pullulan.(AU)

ANÁLISE NA LITERATURA DA AÇÃO PREBIÓTICA DOS EXOPOLISSACARÍDEOS OBTIDOS A PARTIR DE BACTÉRIAS ÁCIDO LÁTICAS

O uso de novos produtos na indústria alimentícia obtidos a partir de microrganismos é crescente, devido especificidade deles e também possibilidade de alterar parâmetros de fermentação otimizando à produção, além da melhoria organolépticas no produto final. As bactérias ácido láticas representam os principais organismos utilizados pela a indústria, com capacidade de converter açúcares, ácidos orgânicos, proteínas ou gorduras em substâncias que agregam sabor, aroma e melhoram a textura e a viscosidade de produtos fermentados devido a produção de Exopolissacarídeos (EPS). O objetivo desse estudo foi analisar na literatura a ação prebiótica dos Exopolissacarídeos obtidos a partir de bactérias ácido láticas. Para isto foi realizado uma revisão sistemática com artigos entre 2011 e 2020, adotando a estratégia PRISMA, usando as bases de dados Web of Science, Science Direct, Scopus e Medline/Pubmed. Para os cruzamentos de dados foram utilizados os operadores or e and e os seguintes descritores: exopolysaccharides, prebiotics, prebiotic potential, prebiotic effects, lactic acid bacteria e probiotics. Como critério de inclusão foram selecionados estudos primários publicados em língua inglesa que associaram a administração de Exopolissacarídeos com ação prebiótica em ensaios in vitro. Dentro dos 7 artigos analisados todos afirmaram que existe uma função prébiótica dos EPS, entretanto precisa-se de estudos mais profundos para verificar os seus efeitos e determinar a duração e dosagens adequadas para o consumo e incorporação do EPS em alimentos tornando-os funcionais.

The use of new products in the food industry obtained from microorganisms is growing, due to their specificity and also the possibility of changing fermentation parameters, optimizing production, in addition to the organoleptic improvement in the final product. Lactic acid bacteria represent the main organisms used by industry, with the ability to convert sugars, organic acids, proteins or fats into substances that add flavor, aroma and improve the texture and viscosity of fermented products due to the production of Exopolysaccharides (EPS) . The aim of this study was to analyze in the literature the prebiotic action of exopolysaccharides obtained from lactic acid bacteria. For this, a systematic review was carried out with articles between 2011 and 2020, adopting the PRISMA strategy, using the Web of Science, Science Direct, Scopus and Medline/Pubmed databases. For data crossings the operators or and and and the following descriptors were used: exopolysaccharides, prebiotics, prebiotic potential, prebiotic effects, lactic acid bacteria and probiotics. As inclusion criteria, primary studies published in English that associated the administration of Exopolysaccharides with prebiotic action in in vitro assays were selected. Within the 7 articles analyzed, all stated that there is a prebiotic function of EPS, however more in-depth studies are needed to verify its effects and determine the appropriate duration and dosages for the consumption and incorporation of EPS in foods, making them functional.

Industrial wastewater as raw material for exopolysaccharide production by Rhizobium leguminosarum

The objective of this study was to evaluate the exopolysaccharide (EPS) production by Rhizobium leguminosarum cultivated in wastewater generated by oil companies (WWOC1 and WWOC2) and fish processing industry (WWFP). The results obtained in Erlenmeyer flasks indicated that the rhizobial strain grew well in industrial wastewater. Generally, wastewater composition affected the growth and the EPS production. WWFP allowed good bacterial growth similar to that obtained with the standard medium (YMB). During growth, various quantities of EPS were produced and yields varied depending on the media. Growing in YMB, EPS production did not exceed 9.7 g/L obtained after 72 h of growth. In wastewater, the maximum EPS value reached 11.1 g/L obtained with the fish processing wastewater, after 72 h of growth. The use of a mixture of the oil company wastewater (WWOC2) and the fish processing wastewater (WWFP) as culture medium affected not only the rhizobial strain growth, but also EPS production. The highest EPS (42.4 g/L, after 96 h of culture) was obtained using a ratio of WWFP and WWOC2 of 50:50 (v:v). Therefore, this work shows the ability of Rhizobium leguminosarum, growing in industrial wastewater as new economic medium, to produce EPS. This biopolymer could be applied in enormous biotechnological areas.(AU)

EFEITO BACTERICIDA DE DIFERENTES SOLUÇÕES PARA Staphylococcus aureus e Staphylococcus epidermidis EM ESTADO SÉSSIL E PLANCTÔNICO UM ESTUDO IN VITRO

Infecções dos sítios cirúrgicos são comuns, mesmo em pacientes utilizando antibioticoterapia profilática. As infecções do sítio cirúrgico são um dos principais contribuintes para a morbidade e mortalidade nos cuidados pós-operatórios. Os biofilmes são um grupo complexo de células microbianas que aderem a matriz de exopolissacarídeos presente na superfície de dispositivos médicos. As infecções associadas ao biofilme nos dispositivos médicos representam um grave problema para a saúde pública e afetam a função do dispositivo. A infecção no implante mamário de silicone ocorre em 7 a 24% das reconstruções mamárias. Estas infecções ocasionam morbidade e possível diminuição de qualidade de vida para os pacientes, além de altos custos com seu tratamento. Os anestésicos locais são utilizados comumente como agente para analgesia pós-operatória e tem um baixo custo, porém sua ação como agente microbicida ainda é controversa. Objetivo: Avaliar o efeito bactericida de diferentes soluções para Staphylococcus aureus e Staphylococcus epidermidis associadas infecção de feridas cirúrgicas e próteses de silicone in vitro. Material e métodos: Para este estudo, foram avaliados os seguintes microrganismos: S. aureus e S. epidermidis. Foi realizada análise com suspensões em solução salina estéril com os microrganismos. O estudo foi realizado em duas etapas: primeiro o teste de difusão em ágar e posterirormente a análise das próteses de silicone. Na primeira etapa, para o teste de difusão em ágar (avaliação das bactérias em estado planctônico), as suspensões com os microrganismos foram inoculadas com auxílio de swab estéril na superfície do ágar sangue. Na sequência, foram confeccionados orifícios equidistantes medindo 3mm de diâmetro e 3mm de profundidade no ágar sangue. Um orifício foi preenchido apenas com 1 gota da solução salina, outro com 1 gota da solução de com antisséptico, outro com 1 gota de Lidocaína pura, outro com 1 gota de solução de Lidocaína e outro com 1 gota da solução com antibiótico. Na segunda etapa, foram utilizadas 36 próteses de silicones (avaliação das bactérias em estado séssil), as quais foram divididos em 3 grupos: próteses contaminadas pelas bactérias e que não receberam tratamento; próteses contaminadas pelas bactérias que receberam tratamento antes da contaminação; e próteses contaminadas pelas bactérias que receberam tratamento após a contaminação. Os tratamentos foram realizados com clorexidina, solução de lidocaína, lidocaína pura e com solução de antibióticos (cefazolina e gentamicina). A incubação foi de 1 semana. As próteses foram semeadas por rolamento em meio de cultura ágar sangue, o qual foi incubado por 48 horas e avaliada a área com formação de colônias através de programa de análise de imagem. Resultados: As placas testadas com solução de lidocaína e a lidocaína pura não apresentaram halo de inibição. A solução de antibióticos apresentou os maiores halos de inibição em todas as bactérias testadas. Na pré-lavagem, não houve crescimento de S. epidermidis com solução de antibióticos. Na lavagem pós-contaminação, não houve crescimento de nenhuma das bactérias com a solução de antibióticos. Na lavagem pós-contaminação, houve diminuição da densidade de colonização com a clorexidina e ausência de crescimento de S. aureus com lidocaína pura e solução de lidocaína. Conclusão: A solução de antibióticos se mostrou uma boa alternativa para o controle, principalmente S. epidermidis, na lavagem pré e pós-contaminação nas próteses de silicone. A lidocaína (pura ou em solução) embora não tenham inibido o crescimento bacteriano nas placas com meio de cultura, foi capaz de diminuir a colonização por S. aureus na lavagem pós-contaminação, mostrando que pode ser utilizada como tratamento adjuvante nestes casos.

Surgical site infections are common, even in patients using prophylactic antibiotic therapy. Surgical site infections are a major contributor to morbidity and mortality in postoperative care. Biofilms are a complex group of microbial cells that adhere to the exopolysaccharide matrix present on the surface of medical devices. Infections associated with biofilm in medical devices pose a serious public health problem and affect the function of the device. Infection in the silicone breast implant occurs in 7 to 24% of breast reconstructions. These infections cause morbidity and possible decrease in quality of life for patients, in addition to high costs with their treatment. Local anesthetics are commonly used as an agent for postoperative analgesia and have a low cost, but their action as a microbicidal agent is still controversial. Objective: To evaluate the bactericidal effect of different solutions for Staphylococcus aureus and Staphylococcus epidermidis associated with surgical wound infection and silicone prostheses in vitro. Material and methods: For this study, the following microrganisms were evaluated: S. aureus and S. epidermidis. Analysis was carried out with suspensions in sterile saline solution with the microrganisms. The study was carried out in two stages: first the agar diffusion test and then the analysis of silicone prostheses. In the first stage, for the agar diffusion test (evaluation of bacteria in planktonic state), the suspensions with the microrganisms were inoculated with the aid of a sterile swab on the surface of the blood agar. Then, equidistant holes were made measuring 3mm in diameter and 3 mm deep in the blood agar. One orifice was filled with 1 drop of saline only, another with 1 drop of antiseptic solution, another with 1 drop of pure Lidocaine, another with 1 drop of Lidocaine solution and another with 1 drop of the antibiotic solution. In the second stage, 36 silicone prostheses (assessment of bacteria in sessile state) were used, which were divided into 3 groups: prostheses contaminated by the bacteria and which did not receive treatment; prostheses contaminated by bacteria and which received treatment before contamination; and prostheses contaminated by bacteria and which received treatment after contamination. Treatments were performed with chlorhexidine, lidocaine solution, pure lidocaine and antibiotics solution (cefazolin and gentamicin). The incubation was 1 week. The prostheses were sown by rolling in a blood agar culture medium, which was incubated for 48 hours and the area with colony formation was evaluated using an image analysis program. Results: The plates tested with lidocaine solution and pure lidocaine did not present an inhibition halo. The antibiotic solution showed the greatest inhibition halos in all the tested bacteria. In the prewash, there was no growth of S. epidermidis with antibiotic solution. In the post-contamination wash, none of the bacteria grew with the antibiotic solution. In post-contamination washing, there was a decrease in the density of colonization with chlorhexidine and absence of growth of S. aureus with pure lidocaine and lidocaine solution. Conclusion: The antibiotic solution proved to be a good alternative for the control, mainly S. epidermidis, in the pre and post-contamination washing in silicone prostheses. Lidocaine (pure or in solution) although it did not inhibit bacterial growth on plates with culture medium, was able to decrease colonization by S. aureus in post-contamination washing, showing that it can be used as an adjuvant treatment in these cases.

Leite de cabras fermentado com Enterococcus hirae como potencial probiótico em cães

Na nutrição canina, o uso de produtos lácteos oriundos de cabras é uma proposta inovadora, assim, objetivou-se elaborar um leite de cabras fermentado com potencial probiótico para cães. Para tanto, Bactérias Ácido Láticas foram isoladas de leite caprino cru (CAP) e de fezes de cães neonatos (CAN), coletados nos municípios de Petrolina PE e Casa Nova BA. Para seleção dos isolados foram realizados dois testes de simulação in vitro: a tolerância ao Trato Gastrintestinal (TGI) de cães e capacidade de acidificação. A partir desta primeira triagem, os demais testes foram conduzidos: presença da enzima -galactosidase; quantificação da produção de exopolissacarídeo (EPS) e produção de diacetil; detecção dos genes codificadores das proteínas de adesão: MapA e Mub; teste de hidrofobicidade na superfície celular; capacidade de eliminação de radicais livres DPPH e caracterização dos fatores de virulência dos isolados de BAL. Posteriormente, os isolados CAP 10, 22, 27 e 28 foram selecionados e identificados como Enterococcus hirae, sendo utilizados para produção do leite de cabra fermentado. Dois tipos de leite fermentado (tratamento e controle) foram elaborados, em triplicata, e suas análises foram conduzidas nos tempos 0, 12, 24 e 36 dias de estocagem, sendo elas microbiológicas e físico-químicas. Para seleção dos isolados, a análise estatística foi feita por análise de variância e as médias comparadas pelo teste Scott-Knott utilizando software SISVAR®. Para avaliações dos leites de cabras fermentados, as análises de variância e teste Tukey a 5% foram feitos por meio do programa estatístico SAS Statistic Analysis System. No estudo, o produto elaborado com as cepas de E. hirae apresentou menor acidez titulável e maior pH (p <0,05) quando comparado com o leite fabricado com fermento comercial (ambos com os valores dentro do estabelecido pela legislação). No entanto, apresentou maior quantidade (p <0,05) de células viáveis, permanecendo em 8 ciclos log10 (UFC / g) em todos os tempos de armazenamento. Diante dos achados, o leite de cabras fermentado com Enterococcus hirae apresenta potencial probiótico para ser incluso na alimentação de cães.

In canine nutrition, the use of dairy products from goats is an innovative proposal, so it was aimed to elaborate a fermented goat's milk with probiotic potential for dogs. For this purpose, Lactic Acid Bacteria were isolated from raw goat milk (CAP) and feces from newborn dogs (CAN), collected in the municipalities of Petrolina - PE and Casa Nova - BA. Two in vitro simulation tests were performed for the selection of the isolates: tolerance to the GI tract of dogs and acidification capacity. From this first screening, the other tests were conducted: presence of the enzyme -galactosidase; quantification of exopolysaccharide (EPS) production and diacetyl production; detection of genes encoding adhesion proteins: MapA and Mub; cell surface hydrophobicity test; capacity of elimination of DPPH free radicals and characterization of the virulence factors of BAL isolates. Subsequently, isolates CAP 10, 22, 27 and 28 were selected and identified as Enterococcus hirae, being used to produce fermented goat milk. Two types of fermented milk (treatment and control) were prepared in triplicate and their analyzes were conducted at 0, 12, 24 and 36 days of storage, being microbiological and physicochemical. For the selection of the isolates, the statistical analysis was performed by analysis of variance and the means compared by the Scott-Knott test using SISVAR® software. For evaluations of fermented goat milks, analyzes of variance and Tukey test at 5% were done using the statistical program SAS - Statistic Analysis System. In the study, the product elaborated with the strains of E. hirae presented lower titratable acidity and higher pH (p <0.05) when compared to the milk produced with commercial yeast (both with values as established by legislation). However, it presented a higher amount (p <0.05) of viable cells, remaining in 8 log10 cycles (CFU / g) at all storage times. In view of the findings, goat's milk fermented with Enterococcus hirae presents probiotic potential to be included in the feeding of dogs.

Quick stimulation of Alcanivorax sp. by bioemulsificant EPS2003 on microcosm oil spill simulation

Oil spill microcosms experiments were carried out to evaluate the effect of bioemulsificant exopolysaccharide (EPS2003) on quick stimulation of hydrocarbonoclastic bacteria. Early hours of oil spill, were stimulated using an experimental seawater microcosm, supplemented with crude oil and EPS2003 (SW+OIL+EPS2003); this system was monitored for 2 days and compared to control microcosm (only oil-polluted seawater, SW+OIL). Determination of bacterial abundance, heterotrophic cultivable and hydrocarbon-degrading bacteria were carried out. Community composition of marine bacterioplankton was determined by 16S rRNA gene clone libraries. Data obtained indicated that bioemulsificant addition stimulated an increase of total bacterial abundance and, in particular, selection of bacteria related to Alcanivorax genus; confirming that EPS2003 could be used for the dispersion of oil slicks and could stimulate the selection of marine hydrocarbon degraders thus increasing bioremediation process.

Extraction and in vitro antioxidant activity of exopolysaccharide by Pleurotus eryngii SI-02

The extraction parameters for Pleurotus eryngii SI-02 exopolysaccharide (EPS) produced during submerged culture were optimized using response surface methodology (RSM). The optimum conditions for EPS extraction were predicted to be, precipitation time 20.24 h, ethanol concentration 89.62% and pH 8.17, and EPS production was estimated at 7.27 g/L. The actual yield of EPS under these conditions was 7.21 g/L. The in vitro antioxidant results of the EPS showed that the inhibition effects of EPS at a dosage of 400 mg/L on hydroxyl, superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals were 59.63 ± 3.72%, 38.69 ± 2.59%, and 66.36 ± 4.42%, respectively, which were 12.74 ± 1.03%, 8.01 ± 0.56%, and 12.19 ± 1.05% higher than that of butylated hydroxytoluene (BHT), respectively. The reducing power of EPS of P. eryngii SI-02 was 0.98 ± 0.05, 60.66 ± 5.14% higher than that of BHT. The results provide a reference for large-scale production of EPS by P. eryngii SI-02 in industrial fermentation and the EPS can be used as a potential antioxidant which enhances adaptive immune responses.

Rizóbios isolados de leguminosas forrageiras do semiárido: Biodiversidade e Eficiência Simbiótica

A fixação biológica de nitrogênio é um processo natural que ocorre entre associações de plantas e bactérias diazotróficas. A maioria das fabáceas forrageiras encontradas na Caatinga possuem alto valor econômico, podendo ser usadas para aumentar o aporte de nitrogênio e matéria orgânica no solo, através da fixação biológica de nitrogênio e ciclagem de nutrientes. Assim o objetivo deste trabalho foi caracterizar morfofisiologicamente isolados de rizóbios nativos das espécies forrageiras Desmanthus pernambucanus (L.) Thellung., Mimosa caesalpiniifolia Benth. e Mimosa tenuiflora (Wild) Poir. Avaliar a resistência ao estresse salino, acidez, toxidade por alumínio e capacidade de solubilização do fosfato de cálcio in vitro, bem como testar a aficiencia simbiótica dos isolados. Autenticar os isolados de rizóbios nativos através da amplificação simultânea de fragmentos dos genes nifH e nodC por meio da técnica duplex PCR. Determinar a diversidade genética dos isolados pela técnica de análise de restrição do DNA ribossomal amplificado (PCR-RFLP) utilizando as endonucleases HhaI, MspI e HinfI e quantificar a produção de compostos indólicos in vitro. O solo usado como substrato para o cultivo das fabáceas foi coletado em pontos específicos dos municípios de Boa Vista, São Sebastião de Lagoa de Roça e Pocinhos no estado da Paraíba. Os nódulos foram obtidos do cultivo de planta isca em casa de vegetação. As bactérias, provenientes dos nódulos, foram isoladas e purificadas em laboratório e após o protocolo de isolamento as bactérias foram avaliadas culturalmente e submetidas aos testes de: Tolerância ao baixo pH + Al3+, diferentes meios salinos e solubilização do fosfato de cálcio in vitro. Em seguida foi realizado um experimento para a avaliação da enficiencia simbiótica dos isolados, inoculados em Vigna unguigulata (L.) Walp. sob condições estéries em casa de vegetação. Após o isolamento e purificação dos isolados, o DNA bacteriano foi extraído e submetido à amplificação dos fragmentos dos genes simbióticos nifH e nodC para posterior avaliação da diversidade genética acessada por PCR-RFLP. Para tal, o gene 16S rRNA foi amplificado, empregando os iniciadores universais 27F (AGAGTTTGATCMTGGCTCAG) e 1492R (TACGGYTACCTTGT TACGACTT). As reações de restrição foram realizadas utilizando as endonucleases HhaI, MspI e HinfI. O produto da digestão foi submetido à eletroforese horizontal em gel de agarose a 3%, em tampão TAE 1% por 80 min a 100 Volts. Para a quantificação dos Compostos Indólicos foi utilizado o método colorimétrico na avaliação das colônias acrescidas com L-triptofano (3,5 mg) e sem L-triptofano em meio de cultira YM. Todos os isolados foram avaliados como bactérias acidificantes de crescimento rápido com principais características morfológicas de colônias irregulares com elevação umbiculada, superfície lisa e produção de exopolissacarídeos moderada. Os isolados DPBV41 e DPBV53 não tiveram crescimento visível, na placa de petri, quando submetidos a um pH 4,5 com e sem alumínio, caracterizando-se como isolados não tolerantes. Os isolados mais afetados pela variação do pH do meio de cultura e toxidade por alumínio foram as bactérias isoladas da fabácea Desmanthus pernambucanus. As colônias de rizóbios que tiveram maiores probabilidades de tolerar os meios de cultura com alto teor de salinidade foram: MTBV77, MTP72, MTP37, DPBV42 e DPBV53 com crescimento máximo em todas as zonas de repicagem da placa de petri. Nas xv avaliações de amplificação simultânea dos genes simbióticos, dentre os 80 isolados de rizóbios testados, 16 amplificaram apenas o gene nifH e cinco isolados amplificaram ambos os genes nifH+nodC simultaneamente. O padrão de bandeamento dos 21 isolados de rizóbios variou de acordo com cada enzima de restrição (HinfI, HhaI e MspI) e resultou em diferentes perfis de restrição transformados em dados binários e avaliados através de matriz de dissimilaridade genética pelo complemento do coeficiente de Jaccard. A partir da matriz de dissimilaridade foi construído um dendrograma pelo método de Ward, com o número de grupos definido pelo método de Mojena, resultando em IV grupos. Em média, a distância entre os pares de genótipos foi de 0,56. Destacaram-se como os pares mais divergentes os isolados DPP1 e MTP44, com distancia de 0,89 e os mais similares MTP72 e MTBV77 com distância de 0,10. A produção de Compostos Indólicos foi maior nas amostras onde houve acréscimo de L-triptofano, precursor do ácido-indol-acético, pelas bactérias MTBV12, MTBV77, MTP78 e MTP37. Os isolados de rizóbios nativos, avaliados nesse estudo, tem alta diversidade genética e se agrupam com base na planta isca da qual são isolados. A produção de Compostos indólicos é variável entre os isolados selecionados e é potencializada na presença do precursor L-Triptofano. Os isolados nativos de Mimosa tenuiflora são mais tolerantes ao estresse salino, acidez, e toxidade por alumínio, em comparação as demais bactérias nativas isoladas de Desmanthus pernambucanus e Mimosa caesalpinifollia. A maioria dos isolados de rizóbios nativos, avaliados neste trabalho, tem baixa capacidade de solubilização do complexo fosfato de cálcio. Todas as bactérias isoladas foram capazes de nodular a espécie Vigna unguigulata.

Biological nitrogen fixation is a natural process that occurs in associations of plants with diazotrophic bacteria. Most of the fodder fabaceae found in the Caatinga have high economic value and can be used to increase the nitrogen and organic matter input in the soil through biological nitrogen fixation and nutrient cycling. Thus the objective of this work was to characterize morphophysiologically isolated of rhizobia native to the forage species Desmanthus pernambucanus (L.) Thellung., Mimosa caesalpiniifolia Benth. and Mimosa tenuiflora (Wild) Poir. To evaluate the resistance to saline stress, acidity, aluminum toxicity and solubilization capacity of calcium phosphate, as well as to test the symbiotic affectivity of the isolates. Authenticate the native rhizobia isolates through the simultaneous amplification of fragments of the nifH and nodC genes by means of the duplex PCR technique. To determine the genetic diversity of the isolates by the amplified ribosomal ADN restriction analysis (PCR-RFLP) technique using the HhaI, MspI and HinfI endonucleases and quantify the production of in vitro indole compounds. The soil used as substrate for the cultivation of the fabaceae was collected at specific points in the municipalities of Pocinhos, São Sebastião de Lagoa de Roça and Boa Vista in the state of Paraíba. The nodules were obtained from the cultivation of a bait plant in a greenhouse. Bacteria from the nodules were isolated and purified in the laboratory and after the isolation protocol the bacteria were culturally evaluated and submitted to the tests of: Tolerance to low pH + Al3+, different saline media and solubilization of calcium phosphate in vitro. An experiment was then carried out to evaluate the symbiotic efficiency of the isolates inoculated in Vigna unguigulata (L.) Walp. under sterile conditions in a greenhouse. After isolation and purification of the isolates, ADN was extracted and subjected to the amplification of the fragments of symbiotic genes nifH and nodC for further evaluation of the genetic diversity accessed by PCR-RFLP. For this, the 16S rRNA gene was amplified using the 27F universal primers (AGAGTTTGATCMTGGCTCAG) and 1492R (TACGGYTACCTTGT TACGACTT). Restriction reactions were performed using the HhaI, MspI and HinfI endonucleases. The digestion product was subjected to horizontal electrophoresis in 3% agarose gel in 1% TAE buffer for 80 min at 100 Volts. For the quantification of Indolic Compounds, the colorimetric method was used to evaluate the colonies added with L-tryptophan (3.5 mg) and without L-tryptophan in YM culture medium. All isolates were evaluated as fast growing acidifying bacteria with the main morphological characteristics of irregular colonies with umbiculate elevation, smooth surface and moderate exopolysaccharide production. The DPBV41 and DPBV53 isolates did not show visible growth in the petri dish when submitted to pH 4.5 with and without aluminum, characterizing as non-tolerant isolates. The isolates most affected by the pH variation of the culture medium and aluminum toxicity were the bacteria isolated from the Desmanthus pernambucanus. The rhizobia colonies that were most likely to tolerate high salinity culture media were: MTBV77, MTP72, MTP37, DPBV42 and DPBV53 with maximum growth in all of the petri dishes. In the simultaneous amplification evaluations of symbiotic genes, among the 80 rhizobia isolates tested, 16 amplified only the nifH gene and five isolates amplified both nifH + nodC genes simultaneously. The xvii genetic variability of the 21 rhizobia isolates varied according to each restriction enzyme (HinfI, HhaI and MspI) and resulted in different restriction profiles transformed into binary data and evaluated through genetic dissimilarity matrix by the complement of the Jaccard coefficient. From the dissimilarity matrix a dendrogram was constructed by the Ward method, with the number of groups defined by the Mojena method, resulting in IV groups. On average, the distance between pairs of genotypes was 0.56. The most divergent pairs were the DPP1 and MTP44 isolates, with a distance of 0.89 and the most similar MTP72 and MTBV77 with a distance of 0.10. The production of Indole Compounds was higher in the samples where there was an increase of L-tryptophan, precursor of indole-acetic acid, by bacteria MTBV12, MTBV77, MTP78 and MTP37. The isolates of native rhizobia have high genetic diversity and are grouped based on the bait plant from which they are isolated. The production of Indole Compounds is variable among the selected isolates and is potentiated in the presence of the L-Tryptophan precursor. The native isolates of Mimosa tenuiflora are more tolerant to saline stress, acidity, and aluminum toxicity compared to other native bacteria isolated from Desmanthus pernambucanus and Mimosa caesalpinifollia. Most of the native rhizobia isolates, evaluated in this work, have low solubilization capacity of the calcium phosphate complex. All the bacteria isolated were able to nodulate the species Vigna unguigulata.

Bacterial exopolysaccharide and biofilm formation stimulate chickpea growth and soil aggregation under salt stress

To compensate for stress imposed by salinity, biofilm formation and exopolysaccharide production are significant strategies of salt tolerant bacteria to assist metabolism. We hypothesized that two previously isolated salt-tolerant strains Halomonas variabilis (HT1) and Planococcus rifietoensis (RT4) have an ability to improve plant growth, These strains can form biofilm and accumulate exopolysacharides at increasing salt stress. These results showed that bacteria might be involved in developing microbial communities under salt stress and helpful in colonizing of bacterial strains to plant roots and soil particles. Eventually, it can add to the plant growth and soil structure. We investigated the comparative effect of exopolysacharide and biofilm formation in two bacterial strains Halomonas variabilis (HT1) and Planococcus rifietoensis (RT4) in response to varying salt stress. We found that biofilm formation and exopolysaccharide accumulation increased at higher salinity. To check the effect of bacterial inoculation on the plant (Cicer arietinum Var. CM-98) growth and soil aggregation, pot experiment was conducted by growing seedlings under salt stress. Inoculation of both strains increased plant growth at elevated salt stress. Weight of soil aggregates attached with roots and present in soil were added at higher salt concentrations compared to untreated controls. Soil aggregation was higher at plant roots under salinity. These results suggest the feasibility of using above strains in improving plant growth and soil fertility under salinity.

PRODUÇÃO E AVALIAÇÃO DE TOXICIDADE DE NANONOMATERIAIS COM POTENCIAL APLICAÇÃO NA MEDICINA VETERINÁRIA

A mastite é uma das principais doenças que acomete os rebanhos leiteiros mundialmente, e tem como principal agente etiológico o Staphylococcus aureus; que recentemente entrou para a lista da Organização mundial de saúde como uma das 12 bactérias multirresistentes que representam as maiores ameaças para a saúde e, portanto, necessitam de amplo esforço de pesquisa e desenvolvimento para novos medicamentos e vacinas mais eficazes. Um importante fator de virulência produzido por esta bactéria é o biofilme, que tem como principal componente o poli-N-acetilglicosamina (PNAG). Dessa forma, o presente trabalho propõe o estudo por espectroscopia vibracional do PNAG de S. aureus e sua aplicação como alternativa não destrutiva para determinação do grau de desacetilação deste polímero, bem como avaliação da toxicidade celular. A caracterização do polissacarídeo foi realizada pelos métodos de ressonância magnética nuclear, raman, infravermelho e espalhamento de luz dinâmico. Testes biológicos foram realizados com células mononucleares de sangue periférico bovino para avaliar a toxicidade aguda do composto. O PNAG mostrou-se tóxico apenas para linfócitos na maior concentração testada (7,5mg/mL) sugerindo assim que quanto maior o grau de desacetilação maior será a taxa de facocitose. Este é um estudo com potencial aplicação para o desenvolvimento de imunoestimuladores para o tratamento da mastite bovina.

Mastitis is one of the principal diseases that affects dairy herds around word. According WHO, Staphylococcus aureus, the main etiological agent of this disease, was recently included in global priority list of antibiotic-resistant bacteria. This pathogen causes extreme threats to health and therefore, requires extensive research and efforts for development of new and effective drugs and vaccines. The biofilm, an important factor of virulence produced by this bacteria, has as the main component the exopolysaccharide (PNAG). Thus, the present research proposes the vibrational spectroscopy evaluation of S. aureus PNAG and its application as non - destructive alternative to determine the degree of polymer deacetylation, and the possible polymer cellular toxicity. The PNAG characterization was performed by nuclear magnetic resonance, Raman, infrared and dynamic light scattering. Biological tests were accomplished using bovine peripheral blood mononuclear cells to evaluate the compound acute toxicity. The polysaccharide was toxic to lymphocytes only at highest concentration (7.5 mg / mL), suggesting that the higher degree of deacetylation, higher the rate of fagocytosis. This study has potential application for the development of immunostimulators for bovine mastitis treatment.

Levan from Bacillus subtilis Natto: its effects in normal and in streptozotocin-diabetic rats

Levan is an exopolysaccharide of fructose primarily linked by β-(2→6) glycosidic bonds with some β-(2→1) branched chains. Due to its chemical properties, levan has possible applications in both the food and pharmaceutical industries. Bacillus subtilis is a promising industrial levan producer, as it ferments sucrose and has a high levan-formation capacity. A new strain of B. subtilis was recently isolated from Japanese food natto, and it has produced levan in large quantities. For future pharmaceutical applications, this study aimed to investigate the effects of levan produced by B. subtilis Natto, mainly as potential hypoglycemic agent, (previously optimized with a molecular weight equal to 72.37 and 4,146 kDa) in Wistar male rats with diabetes induced by streptozotocin and non-diabetic rats and to monitor their plasma cholesterol and triacylglycerol levels. After 15 days of experimentation, the animals were sacrificed, and their blood samples were analyzed. The results, compared using analysis of variance, demonstrated that for this type of levan, a hypoglycemic effect was not observed, as there was no improvement of diabetes symptoms during the experiment. However, levan did not affect any studied parameters in normal rats, indicating that the exopolysaccharide can be used for other purposes.(AU)

Identificação e caracterização de bactérias patogênicas em Tilápias do Nilo (Oreochromis niloticus) comercializadas em feiras livres de Petrolina-PE

O leite e o queijo caprino artesanal em muitos casos são manipulados inadequadamente, propiciando o crescimento de Staphylococcus aureus. Assim, este estudo objetivou a identificação com análise de genes de virulência e o perfil de resistência antimicrobiana de S. aureus provenientes de leite e queijo artesanal caprino. A colheita das amostras ocorreu em sete municípios do semiárido: Petrolina-PE, Santa Filomena-PE, Santa Maria da Boa Vista-PE, Dormentes-PE, Afrânio-PE, Juazeiro-BA e Uauá-BA (totalizando 70 amostras de leite e 30 de queijo). Subsequente, fez-se as análises microbiológicas e a caracterização bioquímica dos isolados. Determinou-se também, o Índice de Resistência Múltipla aos Antimicrobianos (IRMA). Em seguida, foram realizados testes para qualificação e quantificação de formação de biofilmes, assim como produção de exopolissacarídeos (EPS) e hidrofobicidade. Para a confirmação da espécie, foi realizada a análise molecular seguida do sequenciamento. A fim de identificar os isolados com resistência antimicrobiana, utilizou-se os genes mecA e blaZ. E para a detecção dos genes de virulência foi conduzida Reação em Cadeia de Polimerase (PCR) com genes icaA ,icaD, SEA a SEE. No leite e queijo caprino, as médias encontradas para S. aureus nas amostras foram de 4,53 log10 Unidades Formadoras de Colônia/grama (UFC/g) e 6,47 log10 UFC/g, respectivamente. Vinte isolados foram caracterizados fenotipicamente e molecularmente como S. aureus. Estes isolados apresentaram múltipla resistência aos antimicrobianos, tanto no teste com antimicrobianos em disco como também no de microdiluição. No teste de produção de biofilme, os 20 isolados foram classificados como produtores, e dois como fortes produtores. Na análise de produção de EPS, todos foram produtores. Para o teste de hidrofobicidade, todos isolados foram considerados hidrofóbicos, sendo sete isolados identificados como altamente hidrofobicos. Em relação ao gene mecA todos isolados foram negativos. Para o gene blaZ, apenas três isolados foram positivos. Para os genes de virulência como o icaA, nenhum isolado foi positivo, entretanto para icaD, apenas um isolado apresentou positividade. Com relação às enterotoxinas, 12 e 14 isolados foram positivos para a SEC e SED, respectivamente. S. aureus são responsáveis pela intoxicação alimentar. Além disso, sua capacidade diferenciada na propagação genes de resistência antimicrobiana provoca preocupação global pelo aumento de seus fatores de virulência, dificultando seu controle e a eficácia nos tratamentos.

Milk and goat cheese in many cases are handled improperly, leading to the growth of Staphylococcus aureus. Thus, this study aimed at the identification with virulence gene analysis and antimicrobial resistance profile of S. aureus from goat milk and artisanal cheese. Samples were collected in seven municipalities of Petrolina-PE, Santa Filomena-PE, Santa Maria da Boa Vista-PE, Dormentes-PE, Afrânio-PE, Juazeiro-BA and Uauá-BA (totaling 70 samples of milk and 30 of cheese). Subsequently, the microbiological analyzes and biochemical characterization of the isolates were carried out. The Multiple Antimicrobial Resistance Index (IRMA) was also determined. Subsequently, tests were carried out for the qualification and quantification of biofilm formation, as well as exopolysaccharide (EPS) production and hydrophobicity.For the confirmation of the species, the molecular analysis followed the sequencing. In order to identify isolates with antimicrobial resistance, the mecA and blaZ genes were used. And for the detection of virulence genes, Polymerase Chain Reaction (PCR) with icaA, icaD, SEA and SEE genes was conducted. In the milk and goats, the mean values found for S. aureus in the samples were 4.53 log10 colony forming units / gram (CFU / g) and 6.47 log10 CFU / g, respectively. Twenty isolates were characterized phenotypically and molecularly as S. aureus. These isolates showed multiple antimicrobial resistance, both in the antimicrobial test as well as in the microdilution test. In the biofilm production test, the 20 isolates were classified as producers, and two as strong producers. In the analysis of EPS production, all were producers. For the hydrophobicity test, all isolates were considered hydrophobic, with seven isolates identified as highly hydrophobic. Regarding the mecA gene, all isolates were negative. For the blaZ gene, only three isolates were positive. For virulence genes such as icaA, no isolates were positive, however for icaD, only one isolate showed positivity. For enterotoxins, 12 and 14 isolates were positive for SEC and SED, respectively. S. aureus are responsible for food poisoning. In addition, its differentiated capacity in the propagation of antimicrobial resistance genes causes global concern for the increase of its virulence factors, hindering its control and effectiveness in the treatments.

Lignin degradation, ligninolytic enzymes activities and exopolysaccharide production by Grifola frondosa strains cultivated on oak sawdust

Fourteen strains of Grifola frondosa (Dicks.) S. F. Gray, originating from different regions (Asia, Europe and North America) were tested for lignin degradation, ligninolytic enzyme activities, protein accumulation and exopolysaccharide production during 55 days of cultivation on oak sawdust. Lignin degradation varied from 2.6 to7.1 % of dry weight of the oak sawdust substrate among tested strains. The loss of dry matter in all screened fungi varied between 11.7 and 33.0%, and the amount of crude protein in the dry substrate varied between 0.94 to 2.55%. The strain, MBFBL 596, had the highest laccase activity (703.3 U/l), and the maximum peroxidase activity of 22.6 U/l was shown by the strain MBFBL 684. Several tested strains (MBFBL 21, 638 and 662) appeared to be good producers of exopolysaccharides (3.5, 3.5 and 3.2 mg/ml respectively).