Prevalence and phenotypic characterization of Enterococcus spp. isolated from food in Brazil

We evaluated the frequency of enterococci from food and found 95.2% of positivity, being E. faecium and E. faecalis the most frequent species. High-level streptomycin resistance was observed, as well as gelatinase and hemolysis activity, showing the potential role of environmental strains as reservoir of virulence and resistance traits.

Avaliação da efetividade de sanitizantes alcalino-clorados contra Listeria monocytogenes / Evaluation of the effectiveness of alkaline-chlorinated sanitizers against Listeria monocytogenes

Listeria monocytogenes é uma crescente preocupação para a indústria devido à sua capacidade de crescer em temperatura de refrigeração durante o armazenamento de alimentos. Falhas na erradicação dessa bactéria podem resultar em grandes perdas econômicas e sérios problemas de saúde pública. Este trabalho teve por objetivo analisar 32 cepas de L. monocytogenes isoladas de diferentes alimentos frente a dois sanitizantes alcalino clorados em diferentes concentrações e tempos de exposição. Os resultados mostraram que o produto A, na concentração recomendada pelo fabricante, eliminou 46,8% das cepas no tempo mediano de 30 minutos. Já o produto B, eliminou 50% das cepas no tempo mediano de 15 minutos. Concluímos que apesar de estar em suspensão a bactéria mostrou certa resistência ao produto alcalino clorado e o tempo de exposição representa um fator determinante para eficácia do produto.

Listeria monocytogenes is a growing concern for the industry due to its ability to grow at refrigeration temperature for food storage. Failures in the eradication of this bacterium can result in large economic losses and serious problems in public health. This study aimed to analyze 32 strains of L. monocytogenes isolated from different foods in front of two chlorinated alkaline sanitizers at different concentrations and exposure times. The results showed that the product A at the concentration recommended by the manufacturer, removed 46.8% of the strains in the median time of 30 '. Have the product B, eliminated 50% of the strains at the median of 15 '. We conclude that despite being in the suspended bacteria showed some resistance to the chlorinated alkaline product and exposure time is the determining factor for product effectiveness.

Produção in vitro de biofilme por Staphylococcus spp. isolados de salgadinhos e lanches / In vitro biofilm production by Staphylococcus spp. strains isolated from finger-foods and snacks

Staphylococcus aureus is one of the most important food-borne pathogens, and although BrazilianSanitation Surveillance Agency (ANVISA) does not specifically regards for coagulase-negativeStaphylococcus (CNS) isolation from foods, it is known that this group of bacteria possesses genesassociated with biofilm formation and enterotoxins production. In this context, the present study aimedat identifying the S. aureus and CNS in finger-foods and snacks samples, and to evaluate the ability ofthese strains to produce biofilm in vitro by means of two methodologies: Congo Red agar and polystyrenemicroplates cultures. Twenty-two staphylococcal isolates belonging to eight species were obtainedfrom 122 finger-foods, sandwiches and ready-to-eat (RTE) food products. S. aureus, S. warneri and S.haemolyticus were the most frequent isolates. Biofilm production by Staphylococcus spp. was observedin seven (31.8 %) isolates by Congo Red agar technique and three (13.6 %) by polyestirene microplatemethodology. There was no positive isolate biofilm producer by both methodologies. Despite the lownumber of isolates, a concordance of 59.1 % between the tests was found. The ability to produce biofilmis an important virulence factor in Staphylococcus spp., and it can support to define the role of CNS asfood-borne pathogen.

Qualidade microbiológica de lanches e salgados / Microbiological quality of finger food and snacks

Although finger food is convenient, it may be easily contaminated from the stage of preparation to themoment of consumption. This study aimed at evaluating the microbiological quality of finger food and sandwiches sold in Botucatu – SP, Brazil, by following the standards established by the Brazilian Health Surveillance Agency, ANVISA. The analysis was conducted according to APHA. A hundred and twenty two samples of meat, chicken, shrimp, cheese, and vegetable finger food and sandwiches were tested fromAugust 2008 to March 2009. Seventeen (13.9 %) samples of meat, cheese, vegetables and chicken were indisagreement with the ANVISA standards — some of them in more than one parameter. High counting of thermotolerant coliforms and coagulase-positive staphylococci were found in ten (8.2 %) and eight(6.5 %) samples, respectively. Salmonella spp. was detected in two samples (1.6 %). No Bacillus cereus andsulfite-reducing clostridia were isolated. Although only 10 samples (8.2 %) showed pathogenic bacteriacontamination, these results are relevant, since they indicate that the population is generally exposedto risks of acquiring foodborne diseases. Thus, the sanitary authorities might implement actions forsupervising the quality of the food sold in Botucatu, and to strengthen the food sellers to improve thehygienic conditions and be aware of the risks of food contamination.

Neste trabalho foi avaliada a qualidade microbiológica de salgados e sanduíches comercializados emBotucatu-SP, seguindo-se a legislação em vigor. As análises foram realizadas de acordo com APHA. Foramanalisadas 122 amostras de salgados de carne, frango, camarão, queijo e vegetais, e sanduíches no períodode agosto/2008 a março/2009. Dezessete (13,9 %) amostras de carne, queijo, vegetais e frango, e em algumasem mais de um parâmetro, estavam em desacordo com a legislação em vigor. Foram detectadas elevadascontagens de coliformes termotolerantes e estafilococos coagulase-positiva, respectivamente, em dez (8,2 %)e oito (6,5 %) amostras. Salmonella spp. foi isolada em duas amostras (1,6 %). As contagens de Bacillus cereuse de Clostrídio Sulfito Redutor não ultrapassaram os padrões da legislação. A maioria dos salgados mostrouresultados dentro dos padrões estabelecidos pela legislação. A presença de bactérias patogênicas comoS. aureus e Salmonella spp. foi demonstrada em 10 amostras (8,2 %); e este resultado é relevante, pois indicaque a população está exposta a riscos de doenças veiculadas por alimentos. Torna-se necessário colocarem prática a vigilância dos alimentos comercializados em Botucatu, incentivar a melhoria de condiçõesde higiene pelos comerciantes, e ter ciência dos riscos e das implicações da contaminação microbiológicados alimentos.

Inhibitory effect of essential oils against Lactobacillus rhamnosus and starter culture in fermented milk during its shelf-life period

The use of essential oils in foods has attracted great interest, due to their antagonistic action against pathogenic microorganisms. However, this action is undesirable for probiotic foods, as products containing Lactobacillus rhamnosus. The aim of the present study was to measure the sensitivity profile of L. rhamnosus and a yogurt starter culture in fermented milk, upon addition of increasing concentrations of cinnamon, clove and mint essential oils. Essential oils were prepared by steam distillation, and chemically characterised by gas chromatography-mass spectrometry (GC-MS) and determination of density. Survival curves were obtained from counts of L. rhamnosus and the starter culture (alone and in combination), upon addition of 0.04% essential oils. In parallel, titratable acidity was monitored over 28 experimental days. Minimum inhibitory concentration values, obtained using the microdilution method in Brain Heart Infusion medium, were 0.025, 0.2 and 0.4% for cinnamon, clove and mint essential oils, respectively. Cinnamon essential oil had the highest antimicrobial activity, especially against the starter culture, interfering with lactic acid production. Although viable cell counts of L. rhamnosus were lower following treatment with all 3 essential oils, relative to controls, these results were not statistically significant; in addition, cell counts remained greater than the minimum count of 10(8)CFU/mL required for a product to be considered a probiotic. Thus, although use of cinnamon essential oil in yogurt makes starter culture fermentation unfeasible, it does not prevent the application of L. rhamnosus to probiotic fermented milk. Furthermore, clove and mint essential oil caused sublethal stress to L. rhamnosus.

Sinergismo entre óleos essenciais e drogas antimicrobianas sobre linhagens de Staphylococcus aureus e Escherichia coli isoladas de casos clínicos humanos / Synergism between essential oils and antimicrobial drugs against Staphylooccus aureus and Escherichia coli strains from human infections

Estudos com plantas e utilização em terapias combinatórias têm sido estimulados. Verificou-se as possíveis interações entre óleos essenciais de plantas [canela (Cinnamomum zeylanicum Blume Lauraceae), capim-cidreira (Cymbopogon citratus (DC.) Stapf, Poaceae), hortelã-pimenta (Mentha piperita L. Lamiaceae), gengibre (Zingiber officinale Roscoe Zingiberaceae), cravo-da-índia (Caryophillus aromaticus L. Myrtaceae) e alecrim (Rosmarinus officinalis L. Lamiaceae)] combinados a oito drogas antimicrobianas frente a doze linhagens de Staphylococcus aureus e doze de Escherichia coli isoladas de humanos. Após determinação da Concentração Inibitória Mínima (CIM) para os óleos pelo método da diluição foram realizados ensaios para verificação de sinergismo entre os óleos essenciais e os antimicrobianos pela metodologia de Kirby & Bauer. S. aureus foi mais suscetível às interações óleos e drogas, tendo o óleo de capim cidreira apresentado sinergismo com as oito drogas testadas, seguido pelo óleo de hortelã com sete drogas. Nos ensaios com E. coli, houve sinergismo apenas para os óleos de alecrim (três drogas) e capim-cidreira (duas drogas). Não ocorreram casos de antagonismo e os resultados de sinergismo foram influenciados pelos microrganismos estudados.

The studies with plants and combinatory therapy have been stimulated. The interactions between cinnamon (Cinnamomun zeylanicum Blume Lauraceae), lemon grass (Cymbopogon citratus (DC.) Stapf, Poaceae), mint (Mentha piperita L. Lamiaceae), ginger (Zingiber officinale Roscoe Zingiberaceae), clove (Caryophillus aromaticus L. Myrtaceae) and rosemary (Rosmarinus officinalis L. Lamiaceae) and eight antimicrobial drug was carried. It was made against twelve S. aureus and twelve E.coli strains isolated from human specimens. After minimal inhibitory concentration (MIC) values determination of essential oils by dilution agar method, the synergism assays were performed by Kirby and Bauer method. The S. aureus was susceptible to oils and drugs interactions, and the lemon grass oils showed synergism with all drugs tested followed by mint with seven drugs. E.coli assays, synergism was observed only with rosemary (three drugs) and lemon grass (two drugs). No antagonism between drugs and oils tested was observed and the results were variable according to microorganism used.

Effect of naringerin on biochemical parameters in the streptozotocin-induced diabetic rats

Amongst the numerous co-adjuvant therapies which could influence the incidence and progression of diabetic complications, antioxidants and flavonoids are currently being tested in clinical trials. We investigated the effect of naringerin on biochemical parameters in streptozotocin-induced (STZ - 60 mg/kg, i.p.) diabetic rats. Male rats were divided into four groups: G1: untreated controls; G2: normal rats receiving naringerin; G3: untreated diabetics; G4: diabetics rats receiving naringerin. The naringerin (50mg/kg, i.p,) decreased the hyperglycaemia and hyperlipidaemia associated with STZ-diabetes. The concentrations of serum insulin in treated diabetic rats tended to be increased. Naringerin treatment prevents STZ-induced changes in the activities of ALT, AST and LDH in the liver and heart, indicating the protective effect of naringerin against the hepatic and cardiac toxicity caused by STZ. The glycogen level in cardiac and hepatic tissues elevated with naringerin in diabetic rats. The naringerin can improve the glucose and lipid metabolism and is beneficial in preventing diabetic complications.

Dentre as numerosas terapias para minimizar as complicações diabéticas, os antioxidantes e flavonoides são testados na clínica médica. Foi analisado o efeito da naringerina sobre os parâmetros bioquímicos em ratos diabéticos induzidos por estreptozotocina (STZ - 60mg/kg, i.p.). Ratos machos foram divididos em 4 grupos: G1: controle não tratado; G2: ratos normais que receberam naringerina; G3: diabéticos não tratados; G4: ratos diabéticos que receberam naringerina. Naringerina (50mg/kg, i.p.), decresceu a hiperglicemia e a hiperlipidemia em ratos diabéticos. A concentração sérica de insulina em ratos tratados tendeu aumentar. A naringerina preveniu as alterações, provocadas pela estreptozotocina, na atividade hepática e cardíaca de ALT, AST e LDH, indicando o efeito protetor da naringerina sobre estes tecidos, contra toxicidade provocada pela STZ. O nível de glicogênio nos tecidos cardíaco e hepático elevou com a naringerina em ratos diabéticos. A naringerina melhorou o metabolismo da glicose e de lipídios e preveniu as complicações diabéticas.

Antibacterial activity of medicinal plant extracts

The present study aimed at evaluating the in vitro antimicrobial activity of methanolic extracts of some medicinal plants against Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus and Enterococcus sp. The methanolic extract of Caryophyllus aromaticus presented the highest anti-S. aureus activity and was effective against all bacterial strains tested.

Avaliou-se a atividade antimicrobiana in vitro de extratos metanólicos de algumas plantas medicinais frente a Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus e Enterococcus sp. O extrato metanólico de Caryophyllus aromaticus foi o mais eficaz para todas as bactérias testadas e apresentou a melhor atividade anti-S. aureus.

Evaluation of the Diramic system for urine cultures

The use of the Diramic system in microbiological diagnosis of urinary tract infections (UTI) was evaluated. This system was developed at the National Center for Scientific Research of Cuba, and it reads turbidimetric changes of microbial growth in culture media at 37°C incubated for 4 hours. A total of 396 urine specimens were tested in the Laboratory of Microbiology of the School of Medicine - UNESP, Brazil using the Diramic system and the counting of colony forming units per urine millimeter (calibrated loop) as the reference method. The coincidence rate between the two methods was 96.46 percent (382 urine samples), and the differences in results were not significant (p<0.05). Sensitivity and specificity rates were 84.37 percent and 98.80 percent, respectively. False negative and false positive rates were 2.50 percent and 1.01 percent, respectively. The microorganisms isolated from positive urines were: Escherichia coli (68.75 percent); Klebsiella pneumoniae (10.94 percent); yeast (6.25 percent); Pseudomonas aeruginosa (4.69 percent); Enterobacter cloacae (3.12 percent); Proteus mirabilis, coagulase negative Staphylococcus, Morganella morganii, and Citrobacter freundii (1.56 percent each). The Diramic system was effective as screening method for urine cultures, however restrictions in the UTI diagnosis caused by yeasts and patients undergoing antibiotic therapy were negative characteristics of the system.

O sistema Diramic foi avaliado para o diagnóstico das infecções do trato urinário (ITU). O sistema Diramic foi desenvolvido em Cuba e possibilita resultados de diagnóstico das infecções do trato urinário (ITU) em quatro horas e baseia-se na variação da turvação do crescimento microbiano no meio de cultura após incubação a 37°C/4 horas. 396 amostras de urinas provenientes de ambulatórios e enfermarias do HC da FMB-UNESP-Botucatu/SP foram analisadas pelo sistema Diramic. O método da alça calibrada (AC) foi adotado como método de referência. A taxa de coincidência entre os dois métodos foi de 96,46 por cento (382 amostras de urina), não havendo diferença significativa entre os resultados obtidos nos dois métodos. Os resultados para sensibilidade e especificidade foram 84,37 e 98,80 por cento respectivamente e 10 resultados no Diramic foram falsos negativos (2,5 por cento) e 4 falso positivos (1,01 por cento). Os microrganismos identificados nas urinas positivas foram Escherichia coli (68,75 por cento), Klebsiella pneumoniae (10,94 por cento), leveduras (6,25 por cento), Pseudomonas aeruginosa (4,69 por cento), Enterobacter cloacae (3,12 por cento) e Proteus mirabilis, Staphyloccocus coagulase negativo, Morganella morganii e Citrobacter freundii também foram identificadas (1,56 por cento para cada espécie). O método Diramic foi eficiente na triagem das urinoculturas, porém verificou-se algumas restrições quanto ao diagnóstico das infecções do trato urinário quando causadas por leveduras e em pacientes submetidos a antibioticoterapia.

Synergistic effect of propolis and antibiotics on the Salmonella Typhi

O objetivo do presente trabalho foi investigar um possível efeito sinérgico entre extrato alcoólico de própolis do Brasil e Bulgária com alguns antibióticos (Amoxilina, Ampicilina e Cefalexina) utilizados contra Salmonella Typhi. Própolis do Brasil e Bulgária mostraram uma atividade antibacteriana, embora a amostra da Bulgária tenha sido mais eficiente. Ambas as amostras apresentaram um efeito sinérgico com os antibióticos estudados. Pode-se concluir que as amostras de própolis possuem atividade antibacteriana, bem como apresentam efeito sinérgico com antibióticos utilizados contra Salmonella Typhi.

Synergism between plant extract and antimicrobial drugs used on Staphylococcus aureus diseases

Searches for substances with antimicrobial activity are frequent, and medicinal plants have been considered interesting by some researchers since they are frequently used in popular medicine as remedies for many infectious diseases. The aim of this study was to verify the synergism between 13 antimicrobial drugs and 8 plant extracts - "guaco" (Mikania glomerata), guava (Psidium guajava), clove (Syzygium aromaticum), garlic (Allium sativum), lemongrass (Cymbopogon citratus), ginger (Zingiber officinale), "carqueja" (Baccharis trimera), and mint (Mentha piperita) - against Staphylococcus aureus strains, and for this purpose, the disk method was the antimicrobial susceptibility test performed. Petri dishes were prepared with or without dilution of plant extracts at sub-inhibitory concentrations in Mueller-Hinton Agar (MHA), and the inhibitory zones were recorded in millimeters. In vitro anti-Staphylococcus aureus activities of the extracts were confirmed, and synergism was verified for all the extracts; clove, guava, and lemongrass presented the highest synergism rate with antimicrobial drugs, while ginger and garlic showed limited synergistic capacity.

Atividade antimicrobiana de própolis de Apis mellifera obtidas em três regiões do Brasil / Antimicrobial activity of Apis mellifera propolis from three regions of Brazil

As propriedades biológicas da própolis de Apis mellifera são amplamente relatadas sendo comuns variacões nas mesmas em funcão da região onde foram produzidas. A acão antimicrobiana de própolis obtidas em três regiões do Brasil (Botucatu-SP, Mossoró-RN e Urubici-SC) foi investigada sobre linhagens isoladas de infeccões clínicas humanas (Staphylococcus aureus, Escherichia coli, Enterococcus sp, Pseudomonas aeruginosa e Candida albicans). Foram preparados extratos alcoólicos de própolis (EAP) e determinada a Concentracão Inibitória Mínima (CIM) seguida do cálculo da CIM90 por cento. A própolis de Botucatu foi a mais eficiente sobre S. aureus (0,3 por centov/v), Enterococcus sp (1,1 por centov/v) e C. albicans (2,1 por cento v/v). Para E. coli, a própolis eficiente foi de Urubici (7,0 por centov/v) e para P. aeruginosa a de Mossoró (5,3 por centov/v). Os resultados mostram maior sensibilidade das bactérias Gram positivas e levedura em relacão às Gram negativas. É possível concluir que, para os microrganismos testados e amostras de própolis testadas, há diferencas na atividade antimicrobiana em funcão do local de producão e que isso se explica pela diferenca de composicão química da própolis.

Efeito benéfico da propólis sobre a hipercolesterolemia experimental em coelhos / Benefical effects of propolis on experimental hypercholesterolaemia in rabbits

Propolis (bee glue) is one of the major bee hive products and is rich in flavonoids, which are known for their antioxidant effect. To investigate the possible mechanism of propolis therapeutic action, rabbits were distributed into 4 groups (n=6): GI – control; GII – atherogenic diet; GIII – atherogenic diet and ethanol; GIV – atherogenic diet and ethanolic extracts of propolis (EEP=100mg/kg, day). Atherogenic diet (0.14g cholesterol, daily) induced hyperlipidemia in rabbits (male, body weight 2.500?2g) with significant increase of levels of total cholesterol, low density lipoprotein, very low density lipoprotein and triacylglycerol. Treatment with EEP, for 56 days, significantly reduced the levels of these biochemical parameters. The activities of plasma aspartate aminotransferase, alanine aminotransferase and creatine phosphokinase were increased (p<0.05) by atherogenic diet and these increases were largely inhibited by EEP, whereas the adminitration of EEP produced a marked increase in the levels of high density lipoprotein. Treatment of rabbits with EEP resulted in a decrease of hepatic levels of triglycerides, triacylglycerol and total cholesterol. These results suggest that EEP exerts a hypocholesterolaemic effect in high-cholesterol-fed rabbits, and possesses a protective action against the acute hepatic toxicity caused by administration of atherogenic diet

Propolis: anti-Staphylococcus aureus activity and synergism with antimicrobial drugs

Propolis is a natural resinous substance collected by bees from tree exudates and secretions. Its antimicrobial activity has been investigated and inhibitory action on Staphylococcus aureus growth was evaluated. The in vitro synergism between ethanolic extract of propolis (EEP) and antimicrobial drugs by two susceptibility tests (Kirby and Bauer and E-Test) on 25 S. aureus strains was evaluated. Petri dishes with sub-inhibitory concentrations of EEP were incubated with 13 drugs using Kirby and Bauer method and synergism between EEP and five drugs [choramphenicol (CLO), gentamicin (GEN), netilmicin (NET), tetracycline (TET), and vancomycin (VAN)] was observed. Nine drugs were assayed by the E-test method and five of them exhibited a synergism [CLO, GEN, NET, TET, and clindamycin (CLI)]. The results demonstrated the synergism between EEP and antimicrobial drugs, especially those agents that interfere on bacterial protein synthesis.