Revista De Microbiologia最新文献

{"title":"Low cost production and purification of polyclonal antibodies to staphylococcal enterotoxin A","authors":"T. Oliveira, E. Y. Hirooka","doi":"10.1590/S0001-37141999000200006","DOIUrl":"https://doi.org/10.1590/S0001-37141999000200006","url":null,"abstract":"ABSTRACTAn immunization scheme for production of antiserum to staphylococcal enterotoxinA (SEA) is proposed. The reference method of Robbins and Bergdoll was modified toreduce the number of doses and the amount of toxin used per animal. The bestimmunization scheme used injections in days 0, 8, 24, 59, 62 and 67. The amount oftoxin at each injection was 5, 6, 20, 50, 100 and 200 µg, respectively. The total amountof toxin was 381µg, which corresponded to a reduction of 107µg in the amount oftoxin for each animal when compared to the reference method. The average antiserumtiter using the Optimum Sensitivity Plate - OSP was 1:60 and using ELISA the titerwas 1:100.000. The lack of cross-reactivity with other staphylococcal enterotoxinsindicated high specificity of the antibody to SEA. The proposed immunization schemewas adequate to produce specific SEA antisera, with high titers and the aditionaladvantage of reducing the amount of purified SEA required for immunization.Key words: Staphylococcus aureus, enterotoxins, detection, immunizationINTRODUCTIONStaphylococcal food poisoning is a worldwideintoxication caused by the ingestion ofstaphylococcal enterotoxins (SEs), preformed in foodby some Staphylococcus aureus strains. AlthoughS. aureus can be easily detected in foods, neither itspresence necessarily indicates enterotoxinproduction nor the absence of viable staphylococciassures food safety (4).The organism looses viability rapidly after thestationary phase, being replaced by harmlesssaprophytic bacteria. However, the toxins resistboth heat treatment and proteolytic enzymes actionand they can be detected in precooked, pasteurizedand manufactured foods. The direct detection ofenterotoxins in foods requires development ofpractical, rapid and sensitive assays. Currently, thebest methods for enterotoxin identification andquantification depend on the availability of specificantibodies for each enterotoxin type.Immunological methods with monoclonal andpolyclonal antibodies for the enterotoxin detectionat the level of 1 - 2 ng g","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"110 1","pages":"120-124"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87703698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occorrence of Pseudomicrodochium suttonii in Brazil","authors":"Amanda Torres Nunes, M. Cavalcanti, L. A. Queiroz","doi":"10.1590/S0001-37141999000100010","DOIUrl":"https://doi.org/10.1590/S0001-37141999000100010","url":null,"abstract":"Pseudomicrodochium suttonii was isolated from the soil of Derby Square, a leisure area in Recife city, Pernambuco, Brazil. For the isolation, suspensions were made in distilled sterile water. According to the literature, this is probably the first occurrence reported in South America.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"4 1","pages":"52-53"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80809253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Filtration enrichment method for isolation of auxotrophic mutants of Trichoderma harzianum rifai","authors":"A. M. R. Cassiolato, I. S. Melo","doi":"10.1590/S0001-37141999000100008","DOIUrl":"https://doi.org/10.1590/S0001-37141999000100008","url":null,"abstract":"ABSTRACTThe isolation of genetic markers, like drug resistance and auxotrophy, is a laborious butimportant step in genetic research. The isolation of auxotrophic mutants of Trichodermaharzianum using the filtration enrichment technique was more effective than using thetotal isolation technique. Most of 12 auxotrophic mutants exhibited similar growth rateand higher sporulation when compared with the wild type, but only two mutants (TWS-410 and TW5-523) could grow in 500µg/L of benomyl.Key-words: Filtration enrichment technique, auxotrophic mutants, Trichodermaharzianum, benomyl Revista de Microbiologia (1999) 30:43-46ISSN 0001-3714* Corresponding author. Mailing address: EMBRAPA Œ Meio Ambiente, Caixa Postal 69, CEP 13820-000, Jaguariœna, SP, Brasil. Fax: ( +5519)867-8740. INTRODUCTIONTrichoderma spp. Rifai are the most promisingproducers of cellulolytic and chitinolytic enzymes, andalso are currently investigated as biological controlagents of plant pathogens. Their sexual state is unknown,but parasexual cycle has been studied with auxotrophicmarkers permitting selection of heterokaryons and ofpossible diploids (5). The classical method used, totalisolation following mutagenic treatment, is laboriousand yields a low frequency of auxotrophics amongtested survivors (6). Several methods have beendescribed for the selection of auxotrophic mutants offungi. These include biotin-starvation methods that havebeen used for Aspergillus nidulans and comparablemethods have been used in other fungi (6). To inducemutants of Aspergillus niger, Bos et al. (4) used lowdoses of the mutagen ultraviolet light (UV) in order toavoid background mutations or chromosomalrearrangements. Usually, this procedure results in highsurvival and low frequency of mutants among survivingprototrophics. Consequently, an efficient enrichmentstep can be a prerequisite. In this paper we describe theisolation of auxotrophic mutants of Trichodermaharzianum by a filtration enrichment technique basedon the technique developed by Silveira and Azevedo(8) for Metarhizium anisopliae.MATERIALS AND METHODSMicroorganism Œ T. harzianum TW5, originallyisolated from a soybean field in Brazil, was obtainedfrom the fungi collection of National Research Centerfor Monitoring and Assessment of EnvironmentalImpact, EMBRAPA, Brazil. This strain has been shownto be antagonist to the plant pathogens Sclerotiniasclerotiorum and Sclerotinia minor.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"2 1","pages":"43-46"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87761235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence of H. pylori infection in a population from the rural area of Araçuaí, MG, Brazil","authors":"Andreia M. R. Oliveira, G. Rocha, D. Queiroz, M. T. Barbosa, S. Silva","doi":"10.1590/S0001-37141999000100012","DOIUrl":"https://doi.org/10.1590/S0001-37141999000100012","url":null,"abstract":"The prevalence of Helicobacter pylori infection was evaluated by ELISA in a rural population in Minas Gerais, Brazil. A total of 114 among 131 adults (87.0%) and 54 among 87 children (62.0%) presented anti-H. pylori antibodies and the prevalence of the infection increased with age (p < 0.001).","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"81 1","pages":"59-61"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85527762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bovine S protein (vitronectin) increases phagocytosis of Streptococcus dysgalactiae","authors":"L. F. Filippsen","doi":"10.1590/S0001-37141999000100003","DOIUrl":"https://doi.org/10.1590/S0001-37141999000100003","url":null,"abstract":"The effects of bovine S protein (vitronectin) on phagocytosis of Streptococcus dysgalactiae strains isolated from cattle with mastitis were investigated. Phagocytized streptococci were determined by a fluorometric microassay using glass adherent polymorphonuclear neutrophils (PMN). Preincubation of S. dysgalactiae with bovine S protein significantly increased their phagocytosis by PMN. Bovine S protein had no effect on phagocytic killing of non-S protein binding S. pyogenes cultures. Enzymatic digestion of the bovine S protein binding sites on S. dysgalactiae with pronase resulted in a significative reduction of the effects of S protein on phagocytosis. It could thus be concluded that in addition to its role as a promoter of cellular adhesion and complement inhibitor, bovine S protein may also influence the phagocytosis of S. dysgalactiae during inflammatory processes.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"117 1","pages":"15-18"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85900871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Role of the external mycelial network of arbuscular mycorrhizal fungi: III. a study of nitrogen transfer between plants interconnected by a common mycelium","authors":"M. A. Martins, A. F. Cruz","doi":"10.1590/S0001-37141998000400011","DOIUrl":"https://doi.org/10.1590/S0001-37141998000400011","url":null,"abstract":"An experiment under greenhouse conditions was carried out to evaluate the relative contribuition of arbuscular mycorrhizal fungi (AMF) in the process of nitrogen transfer from cowpea to maize plants, using the isotope 15N. Special pots divided in three sections (A, B and C), were constructed and a nylon mesh screen of two diameters: 40µm (which allowed the AMF hyphae to pass but not the plant roots) or 1µm (which acted as a barrier to AM hyphae and plant roots) was inserted between the sections B and C. Section A had 25.5 mg of N/kg using (15NH4)2SO4 as N source. Two cowpea seedlings inoculated with Rhizobium sp. were transplanted with their root systems divided between the sections A and B. Ten days later, 2 seeds of maize were sown into the section C which was inoculated with Glomus etunicatum. Thirty-five days after transplanting, the maize plants were harvested. AMF inoculation increased dry weight and 15N and P content of maize plant shoots. Direct transfer of 15N via AMF hyphae was 21.2%; indirect transfer of 15N mediated by AMF mycelium network, was 9.6%, and indirect transfer not mediated by AM mycelium network , was 69.2%.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"25 1","pages":"289-294"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81999575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chromium uptake from aqueous effluents by immobilized Baker's yeast","authors":"L. Menezes, Vera Nobre Braz, C. Cordeiro","doi":"10.1590/S0001-37141998000400003","DOIUrl":"https://doi.org/10.1590/S0001-37141998000400003","url":null,"abstract":"Leveduras de panificacao imobilizadas em alginato, foram utilizadas com o objetivo de promover a remocao de cromo presente em efluentes. Trabalhou-se com solucoes de cromo de diferentes concentracoes. A fim de avaliar a viabilidade e eficiencia do uso de leveduras de panificacao na remocao de cromo, tres experimentos foram realizados em dois diferentes sistemas de reatores: o primeiro no sistema 1 com 17,5 ml/s e 10, 20, 25 e 30 mg/l Cr; o segundo no sistema 2 com 38,7 ml/s e 20 mg/l Cr; o terceiro no sistema 2.1 com 6,65 ml/s e 20, 30 e 40 mg/l Cr. A media das eficiencias de retencao do cromo variaram entre 86 e 100%.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"29 1","pages":"251-253"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74896106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Production of alpha-amylase in acid cheese whey culture media with automatic pH control","authors":"R. Ferreyra, G. Lorda, A. Balatti","doi":"10.1590/S0001-37141998000400005","DOIUrl":"https://doi.org/10.1590/S0001-37141998000400005","url":null,"abstract":"The influence of aeration and automatic pH control on the production of a-amylase by a strain of Bacillus subtilis NRRL 3411 from acid cheese whey was studied. Tests were carried out in a rotary shaker and in mechanically stirred fermenters. a-amylase was analysed according to DUN’s method. Oxygen absorption rate was determined by Cooper’s method. Cell oxygen demand was determined as oxygen consumption in a Warburg respirometer. The level of dissolved oxygen was measured by means of a galvanic silver-lead electrode. Results suggest the possibility of industrial use of acid cheese whey as a carbon source for a-amylase production, since the yield was similar to that produced with lactose. The highest a-amylase levels 10,000 DUN/ml units were not attained at higher aeration rates -431 mLO2/L.h-. The indicated value correspond to a 96 h process with automatic pH control at 7.5. These conditions resulted in double concentration of a-amylase. The enzyme production was directly related to growth in the form of cell aggregates.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"9 1","pages":"259-264"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91373576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of selected strains of mucorales using fatty acid profiles","authors":"Manuela Silva, G. Manfio, V. Canhos","doi":"10.1590/S0001-37141998000400008","DOIUrl":"https://doi.org/10.1590/S0001-37141998000400008","url":null,"abstract":"The fatty acid profiles of several fungi of the order Mucorales (Zygomycetes), including Backusella lamprospora (Lendner) Benny and R.K. Benj., Benjaminiella youngii P.M. Kirk, Circinella simplex van Tieghem, Cunninghamella blakesleeana Lendner, Mortierella ramanniana (Moller) Linnem., Mucor circinelloides f. janssenii (Lendner) Schipper, Mycotypha microspora Fenner, Rhizomucor miehei (Cooney and R. Emerson) Schipper and Rhizomucor pusillus (Lindt) Schipper, and of Volutella sp. Fr., from the class Ascomycetes, were qualitatively analysed by gas-liquid chromatography in order to determine the taxonomic value of these chemotaxonomic markers. The fatty acids present in all strains were palmitic (16:0), oleic (18:1), linoleic (18:2) and g-linolenic (18:3) acid, with the exception that the latter was not found in Volutella sp. Chemotaxonomic markers for some species and genera were obtained, including a non-identified fatty acid, FAME8 (minimum and maximum retention times of 27.92 and 28.28 minutes) for Rhizomucor miehei CCT 2236 and Rhizomucor pusillus CCT 4133, and FAME3 (minimum and maximum of 16.53 and 16.61 minutes) for Benjaminiella youngii CCT 4121. The chemotaxonomic marker of the order Mucorales was the fatty acid 18:3w6, confirming previous data from literature. The results of the present study suggest that qualitative fatty acid analysis can be an important chemotaxonomic tool for the classification of fungi assigned to the order Mucorales (Zygomycetes).","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"19 1","pages":"276-281"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81809055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cervicovaginal aerobic microflora of women with spontaneous abortion or preterm delivery in Araraquara-Brazil","authors":"M. S. Raddi, N. C. Lorencetti","doi":"10.1590/S0001-37141998000400015","DOIUrl":"https://doi.org/10.1590/S0001-37141998000400015","url":null,"abstract":"Rotina bacteriologica do conteudo vaginal e cervical de 22 mulheres com historico de aborto recente ou ruptura precoce das membranas foi realizada. Chlamydia trachomatis, Streptococcus pyogenes, Streptococcus agalactiae, Candida sp e Gardnerella vaginalis foram isolados em 54,5% (12) das pacientes. Apesar de Ureaplasma urealyticum ter sido frequentemente encontrado (45,5%), somente em 5 das 22 mulheres foi o unico microrganismo presente nos materiais analisados. Esses resultados chamam a atencao para a importância de investigacao quantitativa bem como qualitativa da microbiota genital em gestantes, tendo em vista ter consequencias na gestacao.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"11 1","pages":"311-313"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73107606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}