Essential oils as antibacterial agents against food-borne pathogens: Are they really as useful as they are claimed to be?

Most studies evaluating the use of essential oils (EO) as antibacterial agents focus mainly on minimal inhibitory concentrations (MIC) rather than minimal bactericidal concentrations (MBC). In this work, we compared MICs and MBCs of EO from condiment plants commonly used in Mediterranean Europe, namely Origanum vulgare, Salvia lavandulaefolia, Salvia officinalis, Salvia sclarea and Rosmarinus officinalis, aiming to evaluate their application as disinfecting agents in minimally processed produce. Outbreaks-related pathogens such as Listeria monocytogenes, Pseudomonas aeruginosa and Yarrowia lipolytica were used. Results showed that all EO were able to reduce bacterial growth in all bacterial strains tested, particularly O. vulgare. However, fewer EO exhibited bactericidal activities, and were only effective against one or two bacterial strains, hence eliminating the possibility to use them as broad range disinfectants. Furthermore, the necessary concentrations were too high for food application. Hence, our work suggests the need to evaluate MBC rather than MIC and questions EO usefulness in controlling undesired microorganisms. Overall, and despite the large volume of data published on EO, results obtained were not very encouraging for a realistic application on produce and question the viability of EOs as disinfecting agents in food.

Molecular typing of Salmonella from Sergipe, Northeastern Brazil, showing the epidemiological relationship between poultry and human infection.

Randomly amplified polymorphic DNA (RAPD) has been widely used for epidemiological and phylogenetic purposes ow-ing to its rapidity and efficiency. The aim of this study was to perform genome typing of Salmonella samples isolated from different sources by RAPD profiling. Thirty-three Salmonella samples from the bacterial collection of the Laboratório de Virologia Comparada, Departamento de Morfologia, Universidade Federal de Sergipe, Brazil, and two standard samples were used. RAPD profiling was conducted using six primers of the Ready-To-Go RAPD system. The amplified products were electro-phoresed on 5% polyacrylamide gel and silver-stained. RAPD analysis resulted in reproducible and stable banding patterns and showed high genetic diversity among the isolated strains. The Primer P1-generated dendrogram showed an epidemiologic relationship between the human and poultry isolated samples, highlighting the usefulness of RAPD for molecular typing and epidemiological studies.

[Intranodal myofibroblastoma: a case report]. / Miofibroblastoma intraganglionar: a propósito de un caso.

INTRODUCTION: Myofibroblastomas are part of the heterogeneous group of myofibroblastic tumours, having first been described in 1989. They may be malignant or present a benign behaviour. Clinically they appear as a painless progressively growing mass in the soft tissue. CASE REPORT: A 12-year-old female teenager was referred to our hospital with a 1-year history of a painless growing mass in the inguinal region. A surgical excision was performed; its histological study revealed a proliferation of spindle cells arrayed in a fascicular pattern and with nuclear palisading, occupying the lymph nodes. Immunohistochemichal analysis demonstrated reactivity for vimentin, focally positive for CD34 and smooth muscle actin. She was then diagnosed with intranodal myofibroblastoma. Two years after the surgical excision there was a local recurrence followed by another resection. There have been no new recurrences 3 years after the second intervention. CONCLUSION: The intranodal myofibroblastoma is a rare benign mesenchymal neoplasm, without known pediatric cases and presenting differential diagnosis with other soft tissue tumours. Immunohistochemical studies are essential to establish its myofibroblastic nature.

Miofibroblastoma intraganglionar: a propósito de un caso / Intranodal myofibroblastoma: A case report

Introducción. Los miofiobroblastomas pertenecen a un grupo heterogéneo de tumores fusocelulares que fueron descritos por primera vez en 1989. Pueden tener un comportamiento más agresivo o tratarse de tumores benignos. Clínicamente se presentan como masas en los tejidos blandos, con crecimiento progresivo y no doloroso. Descripción del caso. Adolescente de 12 años, de sexo femenino, acudió a nuestro hospital con una masa inguinal no dolorosa de 1 año de evolución y crecimiento progresivo. Se hizo la escisión quirúrgica del nódulo, cuya histología reveló una proliferación densa de células fusiformes, con haces entrecruzados o en paralelo y con núcleos en empalizada, que ocupaban los ganglios linfáticos. El estudio inmunohistoquímico evidenció una expresión intensa y difusa de vimentina, focalmente positiva para CD34 y actina de músculo liso. El diagnóstico fue de miofiobroblastoma intraganglionar. Hubo una recidiva local, 2 años después con nueva resección. No hay recurrencias tras 3 años de la segunda intervención. Conclusión. El miofiobroblastoma intraganglionar es una neoplasia mesenquimal benigna rara, sin casos conocidos en edad pediátrica y que hace diagnóstico diferencial con otros tumores de partes blandas. Los estudios inmunohistoquímicos son indispensables para establecer su naturaleza miofiobroblástica (AU)

Introduction. Myofiobroblastomas are part of the heterogeneous group of myofiobroblastic tumours, having first been described in 1989. They may be malignant or present a benign behaviour. Clinically they appear as a painless progressively growing mass in the soft tissue. Case Report. A 12-year-old female teenager was referred to our hospital with a 1-year history of a painless growing mass in the inguinal region. A surgical excision was performed; its histological study revealed a proliferation of spindle cells arrayed in a fascicular pattern and with nuclear palisading, occupying the lymph nodes. Immunohistochemichal analysis demonstrated reactivity for vimentin, focally positive for CD34 and smooth muscle actin. She was then diagnosed with intranodal myofibroblastoma. Two years after the surgical excision there was a local recurrence followed by another resection. There have been no new recurrences 3 years after the second intervention. Conclusion. The intranodal myofibroblastoma is a rare benign mesenchymal neoplasm, without known pediatric cases and presenting differential diagnosis with other soft tissue tumours. Immunohistochemical studies are essential to establish its myofibroblastic nature (AU)

Comparative study of the cephalic index of the population from the regions of the north and south of Brazil / Estudio comparativo de índice cefálico de la población de las regiones norte y sur de Brasil

Since the beginning of the century in various countries, investigations to determine the anthropometric characteristics of a population were carried out. The issue of miscegenation in Brazil is of great importance in this study to define a population representative data on the cranial anthropometry. The large size of Brazil, with 8.514.876 km2 leads to an investigation between the two extreme regions of the country: North and South, because of the ethnic composition of their colonizers. This study aims to investigate, compare and rank possible differences in cephalic index of the populations from these regions of Brazil. Therefore, an anthropometric study was performed at the School of Aeronautics Expert (single training center for graduates of Brazilian Air Force), measurements were performed in 110 male students, divided by regions, and also the parents of these students who came from the same region of Brazil. The average width of the head shown in the Northern region is 15.80 +/- 0.69 and 15.75 +/- 0.53 in the Southern region, with significant difference (P <0.05). The average length of the head lodged in the Northern region is 19.54 +/- 0.61 and 19.94 and in the South +/- 0.67, significant difference (P <0.05). With respect to the cephalic index the average in the North is 80.93 +/- 3.84 and in the South 79.06 +/- 3.60, significant difference (P <0.05). In the Northern region, for the classification, mesocephalic is predominant, but with a tendency to brachycephalic and hyperbrachycephalic, dolichocephalic type was rare in the South and the opposite occurs with respect to the rare type, the classification is to mesocephalic predominantly the second type is also brachycephalic, dolichocephalic but it is the third most common, often presented as the brachycephalic type.

Desde el comienzo del siglo en varios países, se llevaron a cabo investigaciones para determinar las características antropométricas de la población. El tema del mestizaje en Brasil es de gran importancia en este estudio para definir una base de datos representativa de la población en la antropometría craneal. El gran tamaño de Brasil, con 8.514.876 km2 nos lleva a realizar una investigación en individuos pertenecientes a las dos regiones extremas del país: Norte y Sur, debido a la composición étnica de sus colonizadores. Este estudio tiene como objetivo investigar, comparar y clasificar las posibles diferencias en el índice cefálico de las poblaciones de estas regiones de Brasil. Por anterior, se llevó a cabo un estudio antropométrico en la Escuela de Aeronáutica de expertos (centro de entrenamiento único para los graduados de la Fuerza Aérea de Brasil). Las mediciones se realizaron en 110 estudiantes de sexo masculino, divididos por regiones, y también en los padres de estos estudiantes que vinieron de la misma región de Brasil. El ancho medio de la cabeza en los individuos de la región Norte fue 15,80 +/- 0,69 cm y 15,75 +/- 0.53 cm en la Región Sur, con diferencias significativas (P <0,05). La longitud media de la cabeza en los individuos de la Región Norte fue 19,54 +/- 0,61cm y 19,94 +/- 0,67 cm en los individuos del Sur, diferencia significativa (P <0,05). Con respecto al índice cefálico en el Norte fue 80,93 +/- 3,84 y emn el Sur 79,06 +/- 3,60, diferencia significativa (P <0,05). En la región Norte, la mesocefalia es predominante, pero con tendencia a la braquicefalia y hiperbraquicefalia. El tipo mesocefálico predominaba en los individuos del Sur pero con distribución más hacia la braquicefalia que hacia la dolicocefalia.

Physical properties and biocompatibility of chitosan/soy blended membranes.

Blends of polysaccharides and proteins are a source for the development of novel materials with interesting and tailorable properties, with potential to be used in a range of biomedical applications. in this work a series of blended membranes composed by chitosan and soy protein isolate was prepared by solvent casting methodology. in addition, cross-linking was performed in situ with glutaraldehyde solutions in the range 5x10(-3)-0.1 M. Furthermore, the influence of the composition and cross-linking on the degradation behaviour, water uptake and cell adhesion was investigated. The obtained results showed that the incorporation of chitosan, associated to network formation by cross linking, promoted a slight decrease of water absorption and a slower degradability of the membranes. Moreover, direct contact biocompatibility studies, with L929 cells, indicate that the cross-linking enhances the capability of the material to support cell growth.

Characterization and cytochemical localization of an ATP diphosphohydrolase from Leishmania amazonensis promastigotes.

An ATP diphosphohydrolase was identified in the plasma membranes isolated from promastigote forms of Leishmania amazonensis. Both ATP and ADP were hydrolysed at similar rates by the enzyme. Other nucleotides such as UTP, GTP and CTP were also degraded, revealing a broad substrate specificity. Adding ATP and ADP simultaneously, the amount of hydrolysis achieved was compatible with the presence of a single enzyme. ATPase activity was not affected by addition of vanadate, ouabain, thapsigargin, dicyclohexylcarbodiimide, oligomycin and bafilomycin A, thus excluding involvement of P-, F- and V-type ATPases. The effects of pH in the range 6.5-8.5 were examined using ATP or p-NPP as substrate. At pH 7.4, the phosphatase activity decreased, and did not show a significant contribution to ATP hydrolysis. In addition, the enzyme was not inhibited by levamisole and ammonium molybdate, excluding alkaline phosphatase and nucleotidase activities, respectively. Sodium azide (5-10 mM) caused inhibition of the ATP and ADP hydrolysis in a dose-dependent manner. Calcium was the best activating metal ion for both ATPase and ADPase activities. Ultrastructural cytochemical microscopy showed ATP diphosphohydrolase on the surface and flagellar pocket of the parasite. We have proposed that L. amazonensis ATP diphosphohydrolase may participate in the salvage pathway of nucleosides.

Coexistence of an unusual form of scabies and lepromatous leprosy. A case report.

A case of unusual crusted (Norwegian) scabies involving the entire skin of a 26 year old Brazilian patient with lepromatous leprosy is reported. The more prominent histopathological findings were acanthosis, hyperkeratosis and crusting with many mites of Sarcoptes scabiei. In the dermis, numerous foamy histiocytes filled with abundant acid-fast bacilli were seen.

Demonstration of mycobacterial antigens in skin biopsies fron suspected leprosy cases in the absence of bacilli.

Skin-biopsies from fifty-six patients suspected of early leprosy from Bahia State, Brazil, were examined histopathologically. The Fite-Faraco staining failed to demonstrate acid-fast bacilli in this material. The prominent features of the lesions were inflammation of the neurovascular bundles and sometimes inflammation of the skin appendages. The non-specific infiltrate was predominantly composed of histiocytes and lymphocytes. In 41 cases (73.2%) epidermal atrophy was also present. The avidin-biotin peroxidase technique was used with primary antibodies to detect bacillary antigens (anti-BCG serum) and nerve branches (anti-S-100 protein serum). Immunohistochemical detection of bacillary antigens using the anti-BCG serum was positive in 28 cases (50%). A positive staining for S-100 protein was observed in 40 cases (71.4%) in dendritic antigen-presenting cells of the skin. The detection of bacillary antigens, together with the clear demonstration of nerve bundles enhanced our capacity to fulfill morphologic criteria for the diagnosis of early leprosy. Our observations indicate that the use of immunohistochemical methods represent a useful tool for the early diagnosis of leprosy.

[Prevalence of cryptosporidiosis in diarrheic syndrome in HIV positive patients]. / Prevalência de criptosporidiose na síndrome diarréica do paciente HIV positivo.

During the period February 1987-June 1988, we examined 542 stool samples of 271 HIV positive patients both with and without full-blown AIDS. One hundred patients with either acute or chronic diarrhea and 180 patients without diarrhea were studied. The stool samples were examined for the presence of Cryptosporidium sp., other protozoa, helmints, and pathogenic enterobacteria. We found a prevalence of 14.3% of Cryptosporidium sp. in patients with full-blown disease and diarrhea. We encountered no Cryptosporidium sp. among asymptomatic patients. The occurrence of diarrhea was significantly associated with a CD4/CD8 ratio lower than 0.4, with the finding of Cryptosporidium sp. in the stools, being a CDC group IV, and with a positive stool culture for pathogenic enterobacteria. The diarrhea caused by Cryptosporidium sp. could not be distinguished, on clinical grounds, from diarrhea caused by other etiologic agents.

PIP: During the period February 1987-June 1988, the authors examined 542 stool samples of 271 HIV-positive patients both with and without fullblown AIDS. 100 patients with either acute or chronic diarrhea and 180 without diarrhea were studied. The stool samples were examined for the presence of Cryptosporidium sp., other protozoa, helminths, and pathogenic enterobacteria. A prevalence of 14.3% of Cryptosporidium sp. in patients with fullblown AIDS and diarrhea was found. No Cryptosporidium sp. was seen among asymptomatic patients. The occurrence of diarrhea was significantly associated with a CD4/CD8 ratio lower than 0.4, with the finding of Cryptosporidium sp. in the stools, being a CDC group IV, and with a positive stool culture for pathogenic enterobacteria. The diarrhea caused by Cryptosporidium sp. could not be distinguished on clinical grounds from diarrhea caused by other etiologic agents. (author's modified) (summaries in ENG, POR

A pathway for putrescine catabolism in Escherichia coli.

Escherichia coli mutants able to grow in putrescine have been isolated from gamma-aminobutyrate mutants. These mutants show putrescine-alpha-ketoglutarate transaminase and gamma-aminobutyraldehyde dehydrogenase activities. Both enzymes have been characterized, the first of them showing an apparent Km for putrescine of 22.5 microM and the second an apparent Km of 37 microM for NAD and 18 microM for delta-1-pyrroline; the optimum pH values were 7.2 and 5.4, respectively, for the two enzymes.

Contaminacao da agua e altos indices de giardiase. / Water contamination and high indices of giardiasis

Submetemos a exame parasitologico de fezes pelo metodo de Hoffmann, Pons e Janer 272 criancas de zero a 14 anos de idade da zona de Cambui-MG. Encontramos 73,2% de positividade para protozoarios e (ou) helmintos. Notamos, no entanto, que a parasitose mais encontrada em todas as faixas etarias, ao contrario dos trabalhos ate agora publicados, foi a giardiase a partir de oito meses de idade, com media de incidencia de 70,3%. Analisando laboratorialmente o sedimento da agua do reservatorio e da distribuicao para a cidade, encontramos cistos de Giardia lamblia. Assim sendo apesar de contarmos com rede de esgotos e agua encanada servindo a maior parte da populacao (carca de 90%), continuamos com altos indices de parasitoses intestinais, principalmente giardiase. Concluimos entao que tambem sao fundamentais a educacao sanitaria, as condicoes socio-economicas da populacao e o controle de qualidade da agua distribuida a populacao