RESUMEN
AIMS: The aim of this study was to evaluate the microbiological quality of commercially prepared ready-to-eat (RTE) sushi by enumerating aerobic mesophilic bacteria (AMB) and thermotolerant coliforms (TC) and detecting Escherichia coli and Salmonella ssp. An isolate was identified as E. coli O157:H7 which was evaluated for its virulence and antimicrobial resistance profiling as well as its ability to form biofilms on stainless steel. METHODS AND RESULTS: There were four sampling events in seven establishments, totalling 28 pools of sushi samples. Mean AMB counts ranged between 5·2 and 7·7 log CFU per gram. The enumeration of TC varied between 2·1 and 2·7 log MPN per gram. Salmonella ssp. were not detected, and one sample was positive for E. coli and was identified as E. coli O157:H7. To the best of our knowledge, this is the first report of E. coli O157:H7 in sushi samples in the world literature. This isolate presented virulence genes stx1, stx2, eae and hlyA. It was also susceptible to 14 antimicrobials tested and had the ability to form biofilms on stainless steel. CONCLUSIONS: There is a need to improve the good hygiene practices adopted in establishments selling sushi in the city of Pelotas, Brazil. In addition, the isolated E. coli O157:H7 carries a range of important virulence genes being a potential risk to consumer health, as sushi is a RTE food. This isolate also presents biofilm formation ability, therefore, may trigger a constant source of contamination in the production line of this food. SIGNIFICANCE AND IMPACT OF THE STUDY: The increase in the consumption of sushi worldwide attracts attention regarding the microbiological point of view, since it is a ready-to-eat food. To our knowledge, this was the first time that E. coli O157:H7 was identified in sushi samples.
Asunto(s)
Escherichia coli O157/aislamiento & purificación , Microbiología de Alimentos , Alimentos Marinos/microbiología , Animales , Antibacterianos/farmacología , Biopelículas/crecimiento & desarrollo , Brasil , Recuento de Colonia Microbiana , Escherichia coli O157/efectos de los fármacos , Escherichia coli O157/genética , Escherichia coli O157/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Acero Inoxidable , Termotolerancia , Virulencia/genéticaRESUMEN
Campylobacter is regarded as the most common bacterial cause of gastroenteritis throughout the world and most cases of human campylobacteriosis can be traced back to the consumption of poultry meat. In Brazil, few studies evaluated the genetic relatedness among Campylobacter isolates. The aim of this research was to evaluate the genetic diversity of Campylobacter spp. isolated from poultry meat products sold on the retail market in Southern Brazil. The presumptive identification of Campylobacter was performed using traditional microbiological analysis, followed by molecular confirmation by PCR. The genetic diversity of isolates was analyzed by pulsed-field gel electrophoresis (PFGE). Campylobacter spp. was isolated from 91.7% (33/36) of the samples, totaling 48 isolates. Campylobacter jejuni was the most prevalent species isolated (90.8%). PFGE data revealed 26 pulsotypes and 18 PFGE patterns composed of only 1 isolate. Campylobacter isolates exhibited high genetic diversity; however, some clones were recurrent in the poultry meat products sold on the retail market. As the south region of Brazil is an important producer and exporter of chicken meat, our results highlight the need to control this pathogen in the food chain in this area of the world to reduce the risks of exposing consumers to campylobacteriosis.
Asunto(s)
Campylobacter coli/genética , Campylobacter jejuni/genética , Microbiología de Alimentos , Variación Genética , Productos Avícolas/microbiología , Animales , Brasil , Campylobacter coli/aislamiento & purificación , Campylobacter jejuni/aislamiento & purificación , Pollos , Electroforesis en Gel de Campo Pulsado/veterinaria , Reacción en Cadena de la Polimerasa/veterinariaRESUMEN
UNLABELLED: Listeria monocytogenes is a foodborne pathogen that has become an important cause of human and animal diseases worldwide. The purpose of this study was to evaluate the serotypes, virulence potential, antimicrobial resistance profile, and genetic relationships of 50 L. monocytogenes isolates from food and food environment in southern Brazil. In this study, the majority of L. monocytogenes isolates belonged to the serotypes 1/2b (42%) and 4b (26%), which are the main serotypes associated with human listeriosis. In addition, all isolates harboured internalin genes (inlA, inlC, inlJ), indicating a virulence potential. The isolates were sensitive to most of the antimicrobial compounds analysed, and five isolates (10%) were multi-resistant. Two isolates harboured antimicrobial resistance genes (tetM and ermB) and in one of them, the gene was present in the plasmid. Moreover, according to the pulsed field gel electrophoresis assay, two multi-resistant isolates were a single clone isolated from food and the processing plant. The isolates were susceptible to the most frequently used antibiotics for listeriosis treatment. However, the presence of multidrug-resistant isolates and antimicrobial resistance genes including in the plasmid could even be transferred between bacterial species, suggesting a potential health risk to consumers and a potential risk of spreading multi-resistance genes to other bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: Listeria monocytogenes is an important agent of foodborne diseases. The results of this study suggest a potential capacity of L. monocytogenes isolates from food and food environment to cause human infections. Antimicrobial multi-resistance profiles were detected in 10%, and two isolates harboured tetM and ermB resistance genes. Moreover, the present research can help to build up a better knowledge about antimicrobial resistance of L. monocytogenes. Additionally, we found one isolate carrying tetM resistance gene in a plasmid, that suggests a possible transmission between commensal and/or other pathogenic bacteria of food environment, thereby raising up concerns regarding bacterial resistance.
Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Farmacorresistencia Bacteriana Múltiple/genética , Listeria monocytogenes/genética , Listeria monocytogenes/aislamiento & purificación , Metiltransferasas/genética , Resistencia a la Tetraciclina/genética , Animales , Proteínas Bacterianas/genética , Brasil , Farmacorresistencia Bacteriana/efectos de los fármacos , Electroforesis en Gel de Campo Pulsado , Microbiología de Alimentos , Humanos , Listeria monocytogenes/patogenicidad , Listeriosis/microbiología , Carne/microbiología , Pruebas de Sensibilidad Microbiana , VirulenciaRESUMEN
OBJECTIVE: The antimicrobial action of five drugs incorporated in temporary denture relines on the fungal biofilm was evaluated. MATERIALS AND METHODS: A Candida albicans biofilm (SC5314) was formed on specimens (10 × 1 mm) of materials (Trusoft and Softone) modified or not (control) by the drugs (nystatin, miconazole, ketoconazole, itraconazole, and chlorhexidine diacetate). Cell viability was determined spectrophotometrically by the tetrazolium salt reduction assay (XTT) after 24 h, 48 h, and 7 and 14 days of incubation. The minimum inhibitory concentrations (MICs) were those which inhibited 90% or more of fungal growth. Fungal susceptibility was confirmed by confocal laser scanning microscopy analysis. RESULTS: The MICs of drugs incorporated in the materials were 0.032, 0.256, 0.128, 0.256, and 0.064 g ml(-1) for nystatin, miconazole, ketoconazole, itraconazole, and chlorhexidine, respectively. Images from nystatin, chlorhexidine, and ketoconazole demonstrated no viable cells. CONCLUSIONS: The antimicrobials incorporated in the resilient materials inhibited fungal growth during 14 days, with lower MICs for nystatin and chlorhexidine.
Asunto(s)
Antifúngicos/farmacología , Biopelículas/efectos de los fármacos , Candida albicans/efectos de los fármacos , Alineadores Dentales/microbiología , Biopelículas/crecimiento & desarrollo , Candida albicans/crecimiento & desarrollo , Clorhexidina , Itraconazol/farmacología , Cetoconazol/farmacología , Miconazol/farmacología , Pruebas de Sensibilidad Microbiana , Nistatina/farmacologíaRESUMEN
OBJECTIVE: The aim of this study was to evaluate the composition of the salivary pellicle (SP) and multispecies biofilm developed on titanium nitrided by cold plasma. METHODS: Titanium discs were allocated into a control group (Ti) and an experimental group (TiN - titanium-nitrided by cold plasma). The disc surface topography was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The chemical composition of the disc surface was determined by X-ray photoelectron spectroscopy (XPS). Stimulated, clarified, and filtered saliva was used to form pellicles on the discs. Proteome analysis of the adsorbed SP proteins was performed by liquid chromatography-mass spectrometry (LC-MS). The surface free energy (SFE) was evaluated before and after SP formation. A multispecies biofilm composed of Actinomyces naeslundii, Streptococcus oralis, Streptococcus mutans, Fusobacterium nucleatum, Veillonella dispar, and Candida albicans was developed on the SP-coated discs. Viable microorganism counts were determined. The biomass and average thickness of biofilms were analyzed by confocal laser-scanning microscopy (CLSM) with COMSTAT software. The biofilm organization was visualized by SEM. RESULTS: The surface topography was similar in both groups. The SFE of the TiN group did not differ from that of the Ti group (p>0.05), although the adsorption of pellicle proteins increased the SFE in both pellicle-coated groups (p<0.001). Different proteins were identified on the Ti and TiN surfaces. The amount of biofilm was similar for both groups (p=0.416), but the counts of F. nucleatum and S. oralis were higher in the TiN group (p<0.001). Similar biofilms were characterized by the COMSTAT data, CLSM images, and SEM images. CONCLUSION: The titanium nitrided by cold plasma exhibited differences in SP composition and multispecies microbial biofilm population compared to the control titanium surface.
Asunto(s)
Biopelículas , Película Dental/química , Película Dental/microbiología , Titanio/química , Microscopía de Fuerza Atómica , Microscopía Confocal , Microscopía Electrónica de Rastreo , Espectroscopía de Fotoelectrones , Gases em Plasma , Proteínas y Péptidos Salivales/química , Programas Informáticos , Propiedades de SuperficieRESUMEN
Crotalus durissus terrificus, C. d. collilineatus, C. d. cascavella and C. d. marajoensis are responsible minor but severe snake bites in Brazil. The venoms of these snakes share the presence of crotoxin, a neurotoxin comprising of two associated components, crotapotin and phospholipase A2 (PLA2). Treatment of the victims with specific antiserum is the unique effective therapeutic measure. The ability of anti-Crotalus antisera produced by the routine using crude venom to immunize horses or purified crotoxin and PLA2 as individual immunogens was compared. Antisera obtained from horses immunized with C. durissus terrificus crude venom were able to recognize and neutralize not only the toxins presents in C. durissus terrificus, but also the ones present in the venoms from C. d. collilineatus, C. d. cascavella and C. d. marajoensis. Antisera from horses immunized with individual crotoxin or PLA2, although in lesser titers, were also able of recognizing the toxins in all four Crotalus species and neutralize the lethality of the C. d. terrificus venom.
Asunto(s)
Antivenenos/biosíntesis , Antivenenos/farmacología , Venenos de Crotálidos/toxicidad , Mordeduras de Serpientes/tratamiento farmacológico , Animales , Antivenenos/inmunología , Bioensayo , Venenos de Crotálidos/inmunología , Crotoxina/inmunología , Modelos Animales de Enfermedad , Caballos/inmunología , Dosificación Letal Mediana , Masculino , Ratones , Neurotoxinas/inmunología , Pruebas de Neutralización , Fosfolipasas A2/inmunología , Mordeduras de Serpientes/inmunología , Mordeduras de Serpientes/mortalidad , Análisis de SupervivenciaRESUMEN
A mastite bovina é uma doença importante na exploração leiteira, não apenas pelas perdas econômicas diretas que promove, mas também pelas perdas indiretas e o potencial risco à saúde pública. Dentre as principais causas de infecções intramamárias, destacam-se as bactérias do gênero Staphylococcus spp., sendo que Staphylococcus aureus é o agente etiológico predominante em mastite subclínica. O objetivo desse trabalho foi verificar a frequência de mastite subclínica em oito rebanhos localizados na região Sul do Rio Grande do Sul (Brasil) e a relação da enfermidade com a presença de S. aureus. Adicionalmente, pesquisou-se a presença de S. intermedius e S. hyicus nas amostras de leite obtidas. Para identificação da doença, utilizou-se o California Mastitis Test (CMT). A identificação da espécie de Staphylococcus spp. foi feita em meio de cultura ágar Baird-Parker, com posterior confirmação das colônias suspeitas em coloração de gram, prova de catalase, pesquisa de coagulase livre e pesquisa de termonuclease. A mastite subclínica foi constatada em 53,6% dos animais testados. A presença de Staphylococcus coagulase positiva foi identificada em 12,6% dos animais com mastite subclínica. Nesses mesmos animais, a bactéria identificada como S. aureus foi o agente etiológico presente em 17,6% dos casos. Adicionalmente, pode-se perceber que, dentre o grupo identificado como coagulase positiva, 85,7% corresponderam a S. aureus, enquanto8,5% mostraram características bioquímicas compatíveis com S. intermedius e 5,8% foram consideradas S. hyicus...
Bovine mastitis is an important disease in dairy farming, not only by promoting direct economic losses, but also for indirect losses and the potential risk to public health. The main causes of intramammary infections include the bacteria of the genus Staphylococcus spp., Staphylococcus aureus being the predominant etiologic agent in subclinical mastitis. The aim of this study was to determine the frequency of subclinical mastitis in eight herds from southern Rio Grande do Sul (Brazil) and the relationship of the disease with the presence of S. aureus. In addition, we checked for the presence of S. intermedius and S. hyicus in the milk samples obtained. For identification of the disease, we used the California Mastitis Test (CMT). Identification of Staphylococcus spp. species was made in Barid-Parker agar culture medium, with subsequent confirmation of suspected colonies by way of Gram stain and catalase test along with free-coagulase and thermonuclease research. Subclinical mastitis was identified in 53.6% of animals tested. The presence of coagulase-positive Staphylococcus was identified in 12.6% of animals with subclinical mastitis. In these same animals, bacteria identified as S. aureus were the etiologic agent present in 17.6% of cases. Additionally, it was revealed that among the group identified as coagulase positive, 85.7% corresponded to S. aureus, while 8.5% had biochemical characteristics consistent with S. intermedius and 5.8% were considered S. hyicus...
Asunto(s)
Animales , Coagulasa/química , Industria Agropecuaria/estadística & datos numéricos , Mastitis Bovina/patología , Salud Pública , Staphylococcus aureus/patogenicidadRESUMEN
Although the effect of acidulated phosphate fluoride gel (APF gel) on caries reduction in permanent teeth is based on evidence, the relevance of the clinical application time is still under debate. Also, the effect of 4- versus 1-min application has not been evaluated in deciduous enamel. In a blind, crossover, in situ study of 14 days, 16 adult volunteers wore palatal appliances containing slabs of human permanent and deciduous enamel. At the beginning of each phase, the slabs were submitted to one of the following treatments: no APF application (negative control); APF gel (1.23% F) application for 1 or 4 min. Biofilm accumulation on the slab surface was allowed and the slabs were subjected eight times a day to 20% sucrose, simulating a high cariogenic challenge condition. On the 15th day of each phase, fluoride retained as CaF(2) and fluorapatite (FAp) was determined on the enamel of the slabs and demineralization was assessed by cross-sectional microhardness. Fluoride as CaF(2) and FAp, formed by APF gel application on the enamel slabs not subjected to the cariogenic challenge, was also determined. APF gel reduced demineralization in both enamel types (p < 0.05), but the difference between 1 and 4 min was not statistically significant (p > 0.05). CaF(2) and FAp formed and retained on deciduous and permanent enamel was significantly higher in APF gel groups (p < 0.05), but no significant difference was found between 1 and 4 min (p > 0.05). The findings suggest that 1 min of APF gel application provides a similar effect on inhibition of demineralization as 4 min, for both permanent and deciduous enamel.
Asunto(s)
Fluoruro de Fosfato Acidulado/uso terapéutico , Cariostáticos/uso terapéutico , Esmalte Dental/efectos de los fármacos , Fluoruros Tópicos/uso terapéutico , Desmineralización Dental/prevención & control , Diente Primario/efectos de los fármacos , Fluoruro de Fosfato Acidulado/administración & dosificación , Adolescente , Adulto , Apatitas/análisis , Apatitas/farmacocinética , Biopelículas/efectos de los fármacos , Fluoruro de Calcio/análisis , Fluoruro de Calcio/farmacocinética , Cariogénicos/farmacología , Cariostáticos/administración & dosificación , Estudios Cruzados , Esmalte Dental/metabolismo , Sacarosa en la Dieta/farmacología , Fluoruros Tópicos/administración & dosificación , Geles , Dureza , Humanos , Método Simple Ciego , Factores de Tiempo , Desmineralización Dental/metabolismo , Diente Primario/metabolismo , Adulto JovenRESUMEN
OBJECTIVE: To analyze the clinical variants, outcomes, and prognosis of Guillain-Barré syndrome (GBS) in a Brazilian population. MATERIALS AND METHODS: Clinical and laboratory data of 149 cases of GBS diagnosed from 1994 to 2007 were analyzed. RESULTS: Acute inflammatory demyelinating polyneuropathy (AIDP) was the most frequent variant (81.8%) of GBS, followed by acute motor axonal neuropathy (AMAN) (14.7%) and acute motor and sensory axonal neuropathy (AMSAN) (3.3%). The incidence of GBS was 0.3/100,000 for the state of Rio Grande do Norte and cases occurred at a younger age. GBS was preceded by infections, with the axonal variant associated with episodes of diarrheas (P = 0.025). Proximal weakness was more frequent in AIDP, and distal weakness predominant in the axonal variant. Compared to 42.4% of cases with AIDP (P < 0.0001), 84.6% of cases with the axonal variant had nadir in <10 days. Individuals with the axonal variant took longer to recover deambulation (P < 0.0001). The mortality of GBS was 5.3%. CONCLUSION: A predominance of the AIDP variant was seen, and the incidence of the disease decreased with age. As expected, the distribution of weakness correlated with the clinical variants, and individuals with the axonal variant had a poorer prognosis.
Asunto(s)
Síndrome de Guillain-Barré/diagnóstico , Síndrome de Guillain-Barré/epidemiología , Adolescente , Adulto , Anciano , Brasil/epidemiología , Femenino , Síndrome de Guillain-Barré/etiología , Humanos , Incidencia , Masculino , Persona de Mediana EdadRESUMEN
The non-classical human leukocyte antigen (HLA) class I genes present a very low rate of variation. So far, only 10 HLA-E alleles encoding three proteins have been described, but only two are frequently found in worldwide populations. Because of its historical background, Brazilians are very suitable for population genetic studies. Therefore, 104 bone marrow donors from Brazil were evaluated for HLA-E exons 1-4. Seven variation sites were found, including two known single nucleotide polymorphisms (SNPs) at positions +424 and +756 and five new SNPs at positions +170 (intron 1), +1294 (intron 3), +1625, +1645 and +1857 (exon 4). Haplotyping analysis did show eight haplotypes, three of them known as E*01:01:01, E*01:03:01 and E*01:03:02:01 and five HLA-E new alleles that carry the new variation sites. The HLA-E*01:01:01 allele was the predominant haplotype (62.50%), followed by E*01:03:02:01 (24.52%). Selective neutrality tests have disclosed an interesting pattern of selective pressures in which balancing selection is probably shaping allele frequency distributions at an SNP at exon 3 (codon 107), sequence diversity at exon 4 and the non-coding regions is facing significant purifying pressure. Even in an admixed population such as the Brazilian one, the HLA-E locus is very conserved, presenting few polymorphic SNPs in the coding region.
Asunto(s)
Alelos , Sitios Genéticos , Genoma Humano/fisiología , Antígenos de Histocompatibilidad Clase I/genética , Polimorfismo de Nucleótido Simple , Brasil , Exones/genética , Femenino , Frecuencia de los Genes/genética , Haplotipos , Humanos , Masculino , Sistemas de Lectura Abierta/genética , Antígenos HLA-ERESUMEN
The availability of inorganic nutrients and certain microbiological agents indicates the quality of the water where this availability is found, and is thus a key indicator for monitoring aquatic life. In this context, the present study was aimed to to evaluate the bathing waters of the Veneza Resort located in the Itapecuru river basin in Caxias, state of Maranhão, Brazil, according to physical, chemical and microbiological parameters. The study was conducted from July to December 2010. The parameters studied were determined by titrimetric chemical analysis and the physical method of spectrophotometric analysis. The microbiological parameters for identification of fecal coliforms were determined using the multiple tubes method. During this period there were levels of phosphorus (phosphate and total phosphorus) above the maximum allowed, thus causing low levels of dissolved oxygen in the water, beginning the process of eutrophication, disequilibrium with the metabolism of the ecosystem.
A disponibilidade de alguns nutrientes inorgânicos e certos agentes microbiológicos em água indica o nível de qualidade em que ela se encontra, sendo um indicador fundamental para o monitoramento da vida em meios aquáticos. Com o presente estudo objetivou-se avaliar a balneabilidade das águas do Balneário Veneza pertencente à Bacia Hidrográfica do Rio Itapecuru na Cidade de Caxias, MA, por meio dos parâmetros físicos, químicos e microbiológicos. O estudo foi desenvolvido no período de julho a dezembro de 2010. Os parâmetros estudados foram determinados pelo método químico de análise titrimétrica e pelo método físico de análise espectrofotométrica. Os parâmetros microbiológicos de identificação de coliformes fecais e totais foram realizados pela técnica dos tubos múltiplos. Nesse período observaram-se níveis de fósforo (fosfato e fósforo total) acima dos valores máximos permitidos, ocasionando assim baixos níveis de oxigênio dissolvido na água desencadeando o processo de eutrofização, com desequilíbrio para o metabolismo do ecossistema.
RESUMEN
In an attempt to clarify the issue of genetic predisposition to leprosy, we examined the distribution of class II human leucocyte antigen variants (DR and DQ) in 70 patients from around the city of Goiânia, Brazil. Only two of the patients presented the tuberculoid form of the disease, whereas 17 fell into the lepromatous category; 51 were intermediate. The allele frequencies found were compared with those in a group of 77 healthy controls. We found an increased frequency of the HLA-DRB1*11 allele in patients with lepromatous leprosy compared with healthy controls (P=0.0132; RR=4.130, 95% Cl: 1.338 to 12.747). These results suggest that the DRB1*11 allele could be related with susceptibility to lepromatous leprosy in Brazil.
Asunto(s)
Alelos , Frecuencia de los Genes , Antígenos de Histocompatibilidad Clase II/genética , Lepra/genética , Adulto , Brasil , Femenino , Frecuencia de los Genes/genética , Predisposición Genética a la Enfermedad , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Cadenas HLA-DRB1 , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
The aim of this study was to evaluate the correlation between patients' and dentist's assessment of dentures and to correlate these variables with objective measures of masticatory function. A sample of 28 edentulous individuals was selected, all wearing both complete dentures for at least 6 months and with no signs or symptoms of temporomandibular joint disorders. They rated their level of satisfaction with their dentures from 0 to 100 by means of a visual analogue scale, and dentures were scored by a dentist from 0 to 9 considering functional aspects. Tooth wear was evaluated on the posterior teeth of dentures considering the lack of occlusal anatomy. Masticatory performance and swallowing threshold tests were performed with an artificial test food (Optocal), and the median particle size was determined by the sieving method. The results showed that the mean satisfaction value of volunteers with their dentures was 49·1 and the median score of dentist's evaluation was 6. The Spearman correlation coefficient revealed no significant correlation between patients' and dentist's assessment of dentures (P>0·05). The median particle size for masticatory performance and swallowing thresholds was 5·5 ± 1·0 and 4·9 ± 1·2 mm, respectively. Data of both masticatory tests showed no significant correlation with patients' satisfaction or with dentist's evaluation of dentures. There was no difference of food comminution between subjects with and without excessive posterior tooth wear. It can be concluded that dentist's and patients' assessment of dentures were not correlated, and no correlation was observed between these variables and masticatory function.
Asunto(s)
Actitud del Personal de Salud , Deglución/fisiología , Dentadura Completa/psicología , Masticación/fisiología , Satisfacción del Paciente , Anciano , Anciano de 80 o más Años , Alisadura de la Restauración Dental , Odontólogos/psicología , Femenino , Alimentos , Humanos , Masculino , Persona de Mediana Edad , Boca Edéntula/fisiopatología , Evaluación de Resultado en la Atención de Salud , Tamaño de la Partícula , Estadísticas no ParamétricasRESUMEN
Anastrepha serpentina (Wiedemann) is recorded for the first time in citrus (Rutaceae) in Brazil. Specimens were obtained from sweet orange (Citrus sinensis) sampled in the municipalities of Belém and Capitão Poço, and from mandarin orange (Citrus reticulata) from Tomé-Açu, state of Pará, Brazil.
Asunto(s)
Citrus/parasitología , Tephritidae/fisiología , Distribución Animal , Animales , BrasilRESUMEN
A method to obtain polyvalent anti-Bitis and polyvalent-anti-Naja antibodies was developed by immunizing horses with B. arietans, B. nasicornis, B. rhinoceros, N. melanoleuca and N. mossambicacrude venoms. Antibody production was followed by the ELISA method during the immunization procedure. Once the desired anti-venom antibody titers were attained, horses were bled and theimmunoglobulins were separated from the sera by (NH4)2SO4 precipitation, cleaved with pepsin and filtered through a 30 kDa ultrafiltration membrane. F(ab´)2 fragments were further purified by Q-Fast Flow chromatography, concentrated by molecular ultrafiltration and sterilized by filtration through 0.22 m membranes. The resulting F(ab´)2 preparations were rich in intact L and in pieces of H IgG(T) chains, as demonstrated by electrophoresis and Western blot and exhibited high antibody titers, as assayed bythe ELISA method. In addition, the preparations possess a significant capacity to neutralize the lethalityof venoms, as estimated by ED50 determination in mouse assay and are free of toxic substances, pyrogen and bacterial or fungal contaminations.
Asunto(s)
Animales , Ratones , Antivenenos/inmunología , Mordeduras de Serpientes , Venenos de Serpiente/clasificación , InmunoterapiaRESUMEN
Atomic force spectroscopy (AFS) was used to measure interaction forces between the tip and nanostructured layers of poly(o-ethoxyaniline) (POEA) in pure water and CuSO4 solutions. When the tip approach and retraction were carried out at low speeds, POEA chains could be physisorbed onto the Si3N4 tip via nonspecific interactions. We conjecture that while detaching, POEA chains were stretched and the estimated chain lengths were consistent with the expected values from the measured POEA molecular weight. The effects from POEA doping could be investigated directly by performing AFS measurements in a liquid cell, with the POEA film exposed to liquids of distinct pH values. For pH > or = 6.0, the force curves normally displayed an attractive region for POEA, but at lower pH values-where POEA is protonated-the repulsive double-layer forces dominated. Measurements in the liquid cell could be further exploited to investigate how the film morphology and the force curve are affected when impurities are deliberately introduced in the liquid. The shape of the force curves and the film morphology depended on the concentration of heavy metal in the liquid cell. AFS may therefore be used to study the interaction between film and analyte, with important implications for the understanding of mechanisms governing the sensing ability of taste sensors.
RESUMEN
Memory consolidation involves a sequence of temporally defined and highly regulated changes in the activation state of several signaling pathways that leads to the lasting storage of an initially labile trace. Despite appearances, consolidation does not make memories permanent. It is now known that upon retrieval well-consolidated memories can become again vulnerable to the action of amnesic agents and in order to persist must undergo a protein synthesis-dependent process named reconsolidation. Experiments with genetically modified animals suggest that some PKC isoforms are important for spatial memory and earlier studies indicate that several PKC substrates are activated following spatial learning. Nevertheless, none of the reports published so far analyzed pharmacologically the role played by PKC during spatial memory processing. Using the conventional PKC and PKCmu inhibitor 12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo[2,3-a]pyrrollo[3,4-c]carbazole (Gö6976) we found that the activity of these kinases is required in the CA1 region of the rat dorsal hippocampus for acquisition and consolidation of spatial memory in the Morris water maze learning task. Our results also show that when infused into dorsal CA1 after non-reinforced retrieval, Gö6976 produces a long-lasting amnesia that is independent of the strength of the memory trace, suggesting that post-retrieval activation of hippocampal PKC is essential for persistence of spatial memory.
Asunto(s)
Hipocampo/enzimología , Aprendizaje por Laberinto/fisiología , Recuerdo Mental/fisiología , Proteína Quinasa C/metabolismo , Percepción Espacial/fisiología , Animales , Reacción de Prevención/efectos de los fármacos , Reacción de Prevención/fisiología , Carbazoles/administración & dosificación , Esquema de Medicación , Inhibidores Enzimáticos/administración & dosificación , Hipocampo/efectos de los fármacos , Indoles/administración & dosificación , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Recuerdo Mental/efectos de los fármacos , Microinyecciones , Proteína Quinasa C/antagonistas & inhibidores , Ratas , Ratas Wistar , Percepción Espacial/efectos de los fármacosRESUMEN
ABSTRACT This work was carried out to establish the association of the fruit flies species, their host plants and their parasitoids in Ilha de Santana, Amapá State, Brazil. Forty four samples from 13 vegetable species were collected, totalizing 4,177 fruits and 78,753 grams. The fruits were collected in 2005, from January to July, and from them 608 puparia were obtained, from which emerged 225 fruit flies of Anastrepha genus and 42 Braconidae parasitoids. Fruit flies emergence were only verified on Spondias mombin L., Psidium guajava L. and Pouteria caimito Radlk samples. The recorded species were A. obliqua Macquart, A. striata Schiner and A. leptozona Hendel. Three species of parasitoids emerged from samples of S. mombin and P. guajava: Doryctobracon areolatus (Szépligeti), Opius sp. and Asobara anatrephae (Muesebeck).
RESUMO Este trabalho objetivou efetuar um levantamento de moscas-das-frutas, suas plantas hospedeiras e seus parasitóides na Ilha de Santana, Estado do Amapá, Brasil. Foram coletadas 44 amostras de frutos de 13 espécies vegetais, totalizando 4.177 frutos e 78.753 g. Os frutos foram coletados no período de janeiro a julho de 2005, sendo obtidos 608 pupários, de onde emergiram 225 moscasdas-frutas pertencentes ao gênero Anastrepha e 42 parasitóides da família Braconidae. Houve emergência de moscas-das-frutas somente de amostras de taperebá (Spondias mombin L.), goiaba (Psidium guajava L.) e abiu (Pouteria caimito Radlk.). As espécies registradas foram A. obliqua Macquart, A. striata Schiner e A. leptozona Hendel. Parasitóides de 3 espécies emergiram de amostras de taperebá e goiaba: Doryctobracon areolatus (Szépligeti), Opius sp. e Asobara anatrephae(Muesebeck).
RESUMEN
Two major memory systems have been recognized over the years (Squire, in Memory and Brain, 1987): the declarative memory system, which is under the control of the hippocampus and related temporal lobe structures, and the procedural or habit memory system, which is under the control of the striatum and its connections (Mishkin et al., in Neurobiology of Learning by G Lynch et al., 1984; Knowlton et al., Science 273:1399, 1996). Most if not all learning tasks studied in animals, however, involve either the performance or the suppression of movement. Animals acquire connections between environmental or discrete sensory cues (conditioned stimuli, CSs) and emotionally or otherwise significant stimuli (unconditioned stimuli, USs). As a result, they learn to perform or to inhibit the performance of certain motor responses to the CS which, when learned well, become what can only be called habits (Mishkin et al., 1984): to regularly walk or swim to a place or away from a place, or to inhibit one or several forms of movement. These responses can be viewed as conditioned responses (CRs) and may sometimes be very complex. This is of course also seen in humans: people learn how to play on a keyboard in response to a mental or written script and perform the piano or write a text; with practice, the performance improves and eventually reaches a high criterion and becomes a habit, performed almost if not completely without awareness. Commuting to school in a big city in the shortest possible time and eschewing the dangers is a complex learning that children acquire to the point of near-perfection. It is agreed that the rules that connect the perception of the CS and the expression of the CR change from their first association to those that take place when the task is mastered. Does this change of rules involve a switch from one memory system to another? Are different brain systems used the first time one plays a sonata or goes to school as compared with the 100th time? Here we will comment on: 1) reversal learning in the Morris water maze (MWM), in which the declarative or spatial component of a task is changed but the procedural component (to swim) persists and needs to be re-linked with a different set of spatial cues; and 2) a series of observations on an inhibitory avoidance task that indicate that the brain systems involved change with further learning.
Asunto(s)
Cuerpo Estriado/fisiología , Hipocampo/fisiología , Memoria , Vías Nerviosas/fisiología , Animales , Reacción de Prevención/fisiología , Humanos , Aprendizaje por LaberintoRESUMEN
In a study of the phlebotomine sandflies (Diptera: Psychodidae) in a forest reserve in Recife, Pernambuco state, north-eastern Brazil, the sandflies landing on human bait between 1.00 and 1.42 h after sunset were collected weekly for 2 years. Although 10,287 sandflies of 10 Lutzomyia species were collected, almost all (96.5%) of the sandflies caught were Lu. umbratilis. This species and several others caught are potential vectors of some of the Leishmania parasites that cause human disease. The recorded landing rate for Lu. umbratilis peaked, at the high level of 333.3 flies/person-hour, during the collections made in May 2003.The relative rarity in the collections of males of some of the species caught probably indicates that these species do not lek on their bloodmeal sources. It is likely that the sizes of the local populations of species that are not very anthrophilic, such as Lu. flaviscutellata, are much larger than indicated by the collections made on human bait.