Technological Applications of Macrococcus caseolyticus and its Impact on Food Safety.

Macrococcus spp. are Gram-positive cocci that belong to the Staphylococcaceae family; they are closely related to staphylococci, but, unlike staphylococci, they are not considered as human pathogens. Macrococcus spp. are recognized as relevant veterinary pathogens, and their presence has been reported in food products of animal origin. Macrococcus caseolyticus, the most studied species of the Macrococcus genus, is associated with the development of aroma and flavor in fermented foods and is, thus, used as starter cultures in fermentations. However, certain important issues regarding food safety must be taken into account when employing these microorganisms in fermentations. Recent studies have reported the presence of genes associated with resistance to methicillin and other antibiotics in M. caseolyticus. This can be harmful to human health as these genes can be transferred to other bacteria present in the food, mainly staphylococcal species. This work, therefore, aims to highlight the importance of a more critical view on the presence of macrococci in foods and the possible indirect risks to human health.

Circulating miRNAs as biomarkers in cardiovascular diseases.

Cardiovascular diseases (CVDs) have shown a high prevalence every year, presenting arterial hypertension as prime factor for their development, also driven by population growth, the aging of population and epidemiologic changes in disease. One of the main challenges in the study of CVD is the identification of reliable biomarkers that can be used in clinical practice and, in this context, microRNAs (miRNAs) have attracted much attention recently. MiRNAs are small non-coding RNAs, identified as post-transcriptional regulators of the expression of several genes both in physiologic and pathologic conditions. They have been studied as possible biomarkers, since they are highly expressed in the vascular system and are crucial modulators for the differentiation, contraction, migration and apoptosis of vascular cells, so modifications in their expression can cause several vascular alterations. Thus, this review aimed to compile the main studies regarding the role of miRNAs in the development of cardiac diseases, their potential applicability in the diagnosis, prognosis and treatment of these disorders. It was possible to verify that alterations in miRNAs expression are present in almost all cardiovascular diseases, such as the development of cardiac hypertrophy, coronary heart disease, heart failure and other conditions. Furthermore, growing evidence indicates that circulating miRNAs may become a potential tool for rapid and easy tests, since they are detected in peripheral blood, also allowing new therapeutic possibilities.

MicroRNA profiling identifies miR-7-5p and miR-26b-5p as differentially expressed in hypertensive patients with left ventricular hypertrophy.

Recent evidence suggests that cell-derived circulating miRNAs may serve as biomarkers of cardiovascular diseases. However, a few studies have investigated the potential of circulating miRNAs as biomarkers for left ventricular hypertrophy (LVH). In this study, we aimed to characterize the miRNA profiles that could distinguish hypertensive patients with LHV, hypertensive patients without LVH and control subjects, and identify potential miRNAs as biomarkers of LVH. LVH was defined by left ventricular mass indexed to body surface area >125 g/m2 in men and >110 g/m2 in women and patients were classified as hypertensive when presenting a systolic blood pressure of 140 mmHg or more, or a diastolic blood pressure of 90 mmHg or more. We employed miRNA PCR array to screen serum miRNAs profiles of patients with LVH, essential hypertension and healthy subjects. We identified 75 differentially expressed miRNAs, including 49 upregulated miRNAs and 26 downregulated miRNAs between LVH and control patients. We chose 2 miRNAs with significant differences for further testing in 59 patients. RT-PCR analysis of serum samples confirmed that miR-7-5p and miR-26b-5p were upregulated in the serum of LVH hypertensive patients compared with healthy subjects. Our findings suggest that these miRNAs may play a role in the pathogenesis of hypertensive LVH and may represent novel biomarkers for this disease.

Effect of sodium reduction and flavor enhancer addition on probiotic Prato cheese processing.

The effect of partial substitution of NaCl with KCl and the flavor enhancers addition (arginine, yeast extract and oregano extract) on Probiotic Prato cheese processing with (L. casei 01, 7logCFU/mL) was investigated. Microbiological (lactic acid bacteria and probiotic counts), physicochemical (proximate composition, pH, proteolysis), bioactivity (antioxidant and angiotensin I-converting enzyme inhibitory activity), rheological (uniaxial compression and creep tests), water mobility (time domain low field magnetic resonance), microstructure (scanning electron microscopy) and sensory evaluation (consumer test) were performed. Sodium reduction and flavor enhancers addition did not constitute an obstacle to the survival of lactic and probiotic bacteria. Proximate composition, antioxidant and angiotensin I-converting enzyme inhibitory activity, and the rheological parameters were affected by the addition of flavor enhancer. No change in the fatty acid profile of cheeses was observed while good performance in the consumer test was obtained by the addition of yeast extract and oregano extract. Prato cheese can be an adequate carrier of probiotics and the addition of different flavor enhancers can contribute developing this functional product in the cheese industry.

Sheep Milk: Physicochemical Characteristics and Relevance for Functional Food Development.

Sheep milk has a high nutritional value and high concentrations of proteins, fats, minerals, and vitamins, as compared to the milks of other domestic species. The physicochemical and nutritional characteristics of sheep milk can be advantageous for the manufacture of products containing prebiotic ingredients and/or probiotic bacteria, which are major categories in the functional food market. Following this technological trend, this review will address the characteristics and advantages of sheep milk as a potentially functional food, as well as the development of sheep milk dairy products containing prebiotics and/or probiotics.

Short communication: Multidrug-resistant Acinetobacter baumannii-calcoaceticus complex isolated from infant milk formula and utensils in a nursery in Rio de Janeiro, Brazil.

Infant milk formulas are not sterile products, and pathogenic bacteria can survive and multiply in these products. This study was performed, initially, to detect the presence of Salmonella spp. in reconstituted infant milk formula and on utensils previously sanitized used in their preparation or distribution in a nursery of a public hospital in Rio de Janeiro. None of the samples tested carried Salmonellaspp. However, further identification of colonies growing on the selective media revealed the presence of several other gram-negative bacteria. Seventeen isolates were identified as belonging to Acinetobacter baumannii-calcoaceticus complex. Fourteen isolates presented a multidrug-resistance profile, by disc diffusion assays, and one of them--JE4--was also resistant to imipenem. The detection of Acinetobacter isolates in this work demonstrates inadequate hygiene practices in the preparation or distribution of infant milk formula.

Ação do fungo metarhizium anisopliae sobre desenvolvimento do díptero muscina stabulans em laboratório / Action of metarhizium anisopliae fungi over the development of muscina stabulans dipteran in laboratory

Avaliou-se o desenvolvimento de Muscina stabulans (Diptera, Muscidae) após exposição ao fungo Metarhizium anisopliae (isolado CG34), sob condições de laboratório. Suspensões de esporos foram preparadas nas concentrações de 10(5), 10(6), 10(7) e 10(8)conídeos/mL-1. Noventa larvas pós-alimentar por tratamento, distribuídas em cinco tratamentos e três repetições, foram mergulhadas por um segundo nas respectivas suspensões, transferidas para placas de Petri com papel filtro umedecido e mantidas em estufa BOD à temperatura de 25ºC, umidade relativa de 80 por cento e fotoperíodo de 12:12 horas até a emergência dos adultos. Foram avaliados a taxa de mortalidade pupal e o período de desenvolvimento pupal. As larvas apresentaram suscetibilidade à ação de M. anisopliae em diferentes concentrações. A mortalidade pupal assim como o tempo de desenvolvimento das pupas (de 8,8 a 10 dias) aumentaram conforme o aumento da concentração de conídios (de zero a 47 por cento). A aplicação de M. anisopliae nesta fase do ciclo biológico comprometeu o desenvolvimento de M. stabulans e interferiu no controle natural de pragas que se desenvolvem no mesmo ambiente.

The development of Muscina stabulans (Diptera, Muscidae) after exposure to Metarhizium anisopliae (CG34 isolated) fungi under laboratory conditions was evaluated. Suspensions of spores were prepared in concentrations of 10(5), 10(6), 10(7), and 10(8)conidia/mL-1. Ninety postfeeding larvae per treatment, divided into five treatments and three repetitions, were dived for one second in the respective suspensions, and transferred to Petri dishes with humidified filter paper and maintained in BOD at 25 ºC with 80 percent relative humidity and a 12:12h photoperiod, until the emergency of adults. The rate of pupal mortality and the period of pupal development were evaluated. The larvae showed susceptibility to the action of M. anisopliae in different levels of concentration. The pupal mortality increased accordingly to the increase in the conidia concentration (from zero to 47 percent), as well as prolonged the time of development of the pupae (from 8.8 to 10 days). The application of M. anisopliae in this phase of the biological cycle compromised the development of M. stabulans and interfered in the natural control of pests that develop in the same environment.

Entomofauna associada ao cultivo de Pleurotus sajor-caju (Fr) Singer (Agaricales: Agaricaceae) no município do Capão do Leão, RS, Brasil / Insects associated with the Pleurotus sajor-caju (Fr) Singer (Agaricales: Agaricaceae) crop in the county of Capão do Leão, RS, Brazil

O objetivo deste trabalho foi conhecer a diversidade de artrópodes associada ao cultivo de Pleurotus sajor-caju em palha de arroz pasteurizada em ambiente semicontrolado, localizado no sul do Rio Grande do Sul. A captura dos espécimes foi realizada no período de abril a maio de 2007, durante a fase de frutificação da cultura, compreendendo 45 dias. Foram realizadas nove coletas com intervalos de 5 dias, utilizando armadilhas INTRAL AL 012 (12 volts). Capturou-se um total de 3.129 indivíduos divididos em cinco ordens com predominância de Diptera (2.874), Hymenoptera (152), Ortoptera (69), Colembola (59) e Coleoptera (38). A ordem Diptera foi a que apresentou o maior número de famílias, sendo Mycetophilidae (2.530), Sciaridae (264), Cecidomyiidae (10), Phoridae (46), Muscidae (4), Calliphoridae (1) e Culicidae (19).

The objective of this research was to know the diversity of arthropods associated to the Pleurotus sajor-caju crop in rice straw pasteurized in a semicontrolled environment, located in the south of the state of Rio Grande do Sul, Brazil. The capture of specimens was carried out in the period of April through May 2007, during the phase of fruit bodies of the crop, lasting 45 days. Nine collections with intervals of 5 days were carried out, using INTRAL AL 012 (12 volt) traps. A total of 3129 individuals divided into five orders with predominance of Diptera (2874), Hymenoptera (152), Ortoptera (69), Colembola (59) and Coleoptera (38) was captured. The Diptera order was the one that presented the biggest number of families, being Mycetophilidae (2530), Sciaridae (264), Cecidomyiidae (10), Phoridae (46), Muscidae (4), Calliphoridae (1) and Culicidae (19).

Staphylococcal antimicrobial peptides: relevant properties and potential biotechnological applications.

Bacteriocins are bacterial antimicrobial peptides with bactericidal activity against other bacteria. Staphylococcins are bacteriocins produced by staphylococci, which are Gram-positive bacteria with medical and veterinary importance. Most bacteriocins produced by staphylococci are either lantibiotics (e.g., Pep5, epidermin, epilancin K7, epicidin 280, staphylococcin C55/BacR1, and nukacin ISK-1) or class II bacteriocins (e.g., aureocins A70 and 53). Only one staphylococcin belonging to class III, lysostaphin, has been described so far. Production of staphylococcins is a self-protection mechanism that helps staphylococci to survive in their natural habitats. However, since these substances generally have a broad spectrum of activity, inhibiting several human and animal pathogens, they have potential biotechnological applications either as food preservatives or therapeutic agents. Due to the increasing consumer awareness of the risks derived not only from food-borne pathogens, but also from the artificial chemical preservatives used to control them, the interest in the discovery of natural food preservatives has increased considerably. The emergence and dissemination of antibiotic resistance among human and animal pathogens and their association with the use of antibiotics constitute a serious problem worldwide requiring effective measures for controlling their spread. Staphylococcins may be used, solely or in combination with other chemical agents, to avoid food contamination or spoilage and to prevent or treat bacterial infectious diseases. The use of combinations of antimicrobials is common in the clinical setting and expands the spectrum of organisms that can be targeted, prevents the emergence of resistant organisms, decreases toxicity by allowing lower doses of both agents and can result in synergistic inhibition.

Bacteriocins as alternative agents for control of multiresistant staphylococcal strains.

AIMS: To investigate the activity of seven staphylococcins, bacteriocins produced by staphylococci, against multiresistant Staphylococcus aureus and coagulase-negative staphylococci (CNS) involved in human infections. METHODS AND RESULTS: Four bacteriocins produced by Staph. epidermidis (Pep5, epidermin, epilancin K7 and epicidin 280) and three produced by Staph. aureus (aureocins A70, A53 and 215FN) were tested. Sixteen Staph. aureus strains, including a representative strain of the endemic Brazilian methicillin-resistant clone (MRSA), and 57 CNS strains were used as indicators. Among the staphylococcins used, Pep5 was able to inhibit 77.2% of the CNS strains and 87.5% of the Staph. aureus strains tested, including the Brazilian MRSA endemic clone, responsible for a large number of hospital-acquired infections in Brazil. On the other hand, aureocin A53 and epidermin presented a high antagonistic activity only against the Staph. aureus strains, being able to inhibit, respectively, 87.5% and 81.3% of them, including also the Brazilian MRSA endemic clone. The remaining bacteriocins inhibited only a low percentage of the nosocomial staphylococcal strains tested. CONCLUSIONS: Aureocin A53 and epidermin have potential applications against MRSA, whereas Pep5 seems to be an attractive agent against both MRSA and CNS, including mupirocin-resistant strains and the Brazilian endemic clone of MRSA, which is also found disseminated in other countries. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacteriocins may represent alternative agents to control important nosocomial pathogens.

Genetic analysis of the bacteriocin-encoding plasmids pRJ6 and pRJ9 of Staphylococcus aureus by transposon mutagenesis and cloning of genes involved in bacteriocin production.

pRJ6 and pRJ9, small Staphylococcus aureus plasmids which code for bacteriocins, exhibited a bactericidal activity against several lactic acid bacteria and strains of Listeria monocytogenes, an important food-borne pathogen. Filter-mating experiments using plasmid derivatives tagged with either Tn551 or Tn917-lac showed that pRJ6, but not pRJ9, could be mobilized by staphylococcal conjugative plasmids. Transposon mutagenesis of both plasmids was also performed. The bacteriocin and immunity structural genes of pRJ6 are part of the same operon, which is located around co-ordinate 4.0, being transcribed from right to left. However, gene cloning experiments using a staphylococcal vector showed some evidence for the involvement of additional functions of pRJ6 in bacteriocin expression. One function involved in pRJ6 mobilization mapped around co-ordinate 5.2, and it appears to be transcribed from left to right. The bactericidal action exerted by strains harbouring pRJ9 appears to reflect the activity of at least two bacteriocins, whose combined action results in a broader spectrum of activity and in a higher antagonistic activity. Gene cloning experiments also supported these assumptions.

[Nutritive value of sunflower seeds (Helianthus annus) (author's transl)]. / Valor nutritivo da torta da semente de girassol (Helianthus annus).

The nutritive value of sunflower seeds (Helianthus annus) was studied and compared to that of casein. Thirty-six male rats, Wistar strain, aged 23 days, were divided into two groups and fed (a) a sunflower cake meal diet, and (b) a casein diet. The results indicate that due to its high protein level (52.06%) and coefficient of digestibility (95 CD) sunflower can be used as a feeding formula although its PER does not recommend its use as a milk substitute.

[Biological value of a soy-corn-wheat based noodle (macaroni) supplemented with lysine (author's transl)]. / Valor biológico de uma massa alimentícia (macarrão) à base de soja-milho-trigo suplementada com lisina

The biological value of a soy-corn-wheat based noodle (macaroni) prepared by the General Food Corporation was studied. The protein level of the noodle was of 20.5g%. Thirty-six Albino rats were used in this experimental. The animals were divided into sex groups of six animals each. The experimental groups were fed: a) cooked macaroni without lysine; and b) macaroni supplemented with increasing levels of L-lysine HCL. The control group received commercial casein. The protein level of the experimental diets was of 10g%. At the end of the fourth week of the experiment some rats showed a slight difference in the growth curve, specially the animals fed macaroni without lysine. However, statistical analysis did not show a significant difference. The protein efficiency ratio (PER) of the experimental groups was similar to that of the control group, but when the lysine level of the diets increased there was a corresponding increase in the PER. No significant difference was noted too. These results suggest that lysine do not improve the biological value of the noodle.

[Nutritive value of macaçar bean (Vigna unguiculatta L.) Walp (author's transl)]. / Valor nutritivo do feijão maccar

The biological value of dry and immature macaçar bean (Vigna unguiculatta L.) Walp, isolated or associated to manioc flour, was studied. Thirty-six male Albino rats, Wistar strain, aged 23 days, were divided into six groups and fed experimental and control (casein) diets for 28 days. The weight curve and the PER of the animals fed dry and immature macaçar bean either isolated or associated to manioc flour were lower than those of the casein group. The data lead to the conclusion that the macaçar bean is to be used as a food supplement only, due to its low biological value.