Immunity and physiological changes in adult honey bees (Apis mellifera) infected with Nosema ceranae: The natural colony environment.

Nosema ceranae is a microsporidium that infects Apis mellifera, causing diverse physiological and behavioral alterations. Given the existence of individual and social mechanisms to reduce infection and fungal spread in the colony, bees may respond differently to infection depending on their rearing conditions. In this study, we investigated the effect of N. ceranae in honey bee foragers naturally infected with different fungal loads in a tropical region. In addition, we explored the effects of N. ceranae artificially infected young bees placed in a healthy colony under field conditions. Honey bees naturally infected with higher loads of N. ceranae showed downregulation of genes from Toll and IMD immune pathways and antimicrobial peptide (AMP) genes, but hemolymph total protein amount and Vitellogenin (Vg) titers were not affected. Artificially infected bees spread N. ceranae to the controls in the colony, but fungal loads were generally lower than those observed in cages, probably because of social immunity. Although no significant changes in mRNA levels of AMP-encoding were observed, N. ceranae artificially infected bees showed downregulation of miR-989 (an immune-related microRNA), lower vitellogenin gene expression, and decreased hemolymph Vg titers. Our results demonstrate for the first time that natural infection by N. ceranae suppresses the immune system of honey bee foragers in the field. This parasite is detrimental to the immune system of young and old bees, and disease spread, mitigation and containment will depend on the colony environment.

Methacrylate: An alternative fixing agent for identifying the botanical origin of propolis.

PREMISE: A new technique was developed to identify the botanical origin of propolis, a resin-like material made by bees by mixing saliva and beeswax with plant buds and exudates, using methacrylate for permanent slide preparation. METHODS AND RESULTS: Propolis samples were fixed in methacrylate to produce permanent slides. The anatomical structures of the plant fragments in the methacrylated propolis were compared with propolis slides prepared using conventional techniques that consist of propolis sediment obtained during a series of solvent reactions, filtration, and centrifugations, which cost a similar amount to produce. The techniques resulted in qualitative differences between the slides obtained. The methacrylated propolis sections allowed the detailed observation and identification of plant anatomical structures that were obscured in samples prepared using the conventional procedure. This clarity enabled the detailed evaluation of valuable taxon-diagnostic characters in a permanent slide, which can also be used for histochemical tests. CONCLUSIONS: The methacrylated embedding of propolis is an affordable technique that could be implemented as a routine laboratory procedure. This new technique enables the efficient determination of the botanical origin of propolis.

Spores of Paenibacillus larvae, Ascosphaera apis, Nosema ceranae and Nosema apis in bee products supervised by the Brazilian Federal Inspection Service

ABSTRACT Due to their ecological and economic importance, honey bees have attracted much scientific attention, which has intensified due to the recent population decline of these insects in the several parts of the world. Among the factors related to these patterns, infection by pathogens are the most relevant, mainly because of the easy dissemination of these microorganisms. Although no zoonotic diseases are associated with these insects, the presence of infectious agents in bee products should still be considered because they play a role as disease dispersers, increasing the risk to animal health. Because of the possibility of dispersion of pathogens via bee products, this work aimed to identify the presence of spores of the pathogens Paenibacillus larvae, Ascosphaera apis and Nosema spp. in samples of honey, pollen and royal jelly that are registered with Brazil's Federal Inspection Service (S.I.F.) and commercially available in the state of São Paulo. Of the 41 samples of bee products analyzed, only one showed no contamination by any of these pathogens. N. ceranae and P. larvae had the highest prevalence considering all the samples analyzed (present in 87.80% and 85.37% of the total, respectively), with N. apis present in 26.83% and A. apis present in 73.17% of the samples. These results provide support for the formulation of government regulations for sanitary control of exotic diseases by preventing dispersion of pathogens, including through illegal importation, since local and international trade and the transfer of colonies between regions play important roles in the dispersion of these microorganisms.

Corrigendum to "Antioxidant Activity of a Geopropolis from Northeast Brazil: Chemical Characterization and Likely Botanical Origin".

[This corrects the article DOI: 10.1155/2017/4024721.].

Antioxidant Activity of a Geopropolis from Northeast Brazil: Chemical Characterization and Likely Botanical Origin.

Geopropolis is a product containing wax, plant resin, and soil particles. It is elaborated by stingless bees of tribe Meliponini. Methanol extracts of sample of geopropolis produced by Scaptotrigona aff. depillis [corrected] ("mandaguari") in the state of Rio Grande do Norte (RN, northeast Brazil) were analyzed for the determination of standard parameters (total phenols, total flavonoids, and radical scavenging activity) and chemical characterization by HPLC-DAD-MS/MS analysis. The sample analyzed has high contents of total phenols and flavonoids, as well as high antioxidant activity. The constituents characterized were mainly flavonols, such as quercetin methyl ethers, and methoxychalcones. Such chemical profile is similar to the composition of a green propolis from the same area of RN, which is produced by Africanized Apis mellifera, using shoot apices of Mimosa tenuiflora, popularly known as "jurema-preta." This finding provides evidence that "mandaguari" geopropolis and honeybee propolis have the same botanical origin in RN. The sharing of a plant resin source by phylogenetically distant bees (Apinae and Meliponinae) suggests that bee genetic factors play little role in the choice of plants for resin collection and that the availability of potential botanical sources plays a decisive role.

New propolis type from north-east Brazil: chemical composition, antioxidant activity and botanical origin.

BACKGROUND: Propolis is a bee product with wide diversity of biological activity. It has a complex composition, which is dependent on its botanical source. The present study aimed to determine the chemical profile, antioxidant activity and botanical origin of two samples of a propolis type from two locations of the state of Rio Grande do Norte (RN, north-east Brazil). RESULTS: The standard chemical characteristics of the RN propolis are similar or superior to the internationally marketed Brazilian green propolis. RN propolis from two locations have high antioxidant activity, corresponding to 10% (municipality of Afonso Bezerra) and 13% (municipality of Alto do Rodrigues) of quercetin activity by the 2,2-diphenyl-1-picrylhydrazyl method and to 15% (both locations) by the ß-carotene discoloration method. High-performance liquid chromatography with diode array detection (HPLC-DAD)-electrospray ionization-tandem mass spectrometry analyses revealed that most constituents of the RN propolis are flavonoids, mainly flavonols and chalcones. HPLC-DAD analysis of ethanol extracts revealed a great similarity between the chemical profile of RN propolis and shoot apices of 'jurema-preta' (Mimosa tenuiflora, Leguminosae, Mimosoideae). CONCLUSION: 'Jurema-preta' shoot apices are likely resin sources of RN propolis. The chemical characteristics and antioxidant property of RN propolis provide promising prospects for the introduction of this type of propolis into the apicultural market. © 2017 Society of Chemical Industry.

Nosema ceranae has been present in Brazil for more than three decades infecting Africanized honey bees.

Until the mid-1990s, the only microsporidium known to infect bees of the genus Apis was Nosema apis. A second species, Nosema ceranae, was first identified in 1996 from Asian honey bees; it is postulated that this parasite was transmitted from the Asian honey bee, Apis cerana, to the European honey bee, Apis mellifera. Currently, N. ceranae is found on all continents and has often been associated with honey bee colony collapse and other reports of high bee losses. Samples of Africanized drones collected in 1979, preserved in alcohol, were analyzed by light microscopy to count spores and were subjected to DNA extraction, after which duplex PCR was conducted. All molecular analyses (triplicate) indicated that the drones were infected with both N. ceranae and N. apis. PCR products were sequenced and matched to sequences reported in the GenBank (Acc. Nos. JQ639316.1 and JQ639301.1). The venation pattern of the wings of these males was compared to those of the current population living in the same area and with the pattern of drones collected in 1968 from Ribeirão Preto, SP, Brazil, from a location close to where African swarms first escaped in 1956. The morphometric results indicated that the population collected in 1979 was significantly different from the current living population, confirming its antiquity. Considering that the use of molecular tools for identifying Nosema species is relatively recent, it is possible that previous reports of infections (which used only light microscopy, without ultrastructural analysis) wrongly identified N. ceranae as N. apis. Although we can conclude that N. ceranae has been affecting Africanized honeybees in Brazil for at least 34 years, the impact of this pathogen remains unclear.

Fornecimento de substituto de pólen na redução da mortalidade de Apis mellifera L. causada pela Cria Ensacada Brasileira / Pollen substitute on the reduction of Apis mellifera L. mortality caused by Brazilian Sac Brood

A cria ensacada brasileira é uma das piores enfermidades de abelhas Apis mellifera L. africanizadas, principalmente do Sudeste do Brasil. Ela afeta o desenvolvimento das larvas, após serem alimentadas pelas abelhas nutrizes com o pólen do barbatimão (Stryphnodendron polyphyllum e Stryphnodendron adstringens), ocasionando a morte entre os estágios de pré-pupa e pupa. O objetivo deste trabalho foi verificar o efeito do substituto de pólen na redução da mortalidade da cria ensacada brasileira durante o florescimento do Stryphnodendron adstringens. Foram utilizados dois tratamentos: as colmeias do tratamento 1 receberam semanalmente substituto de pólen (mistura de farinha de soja, fubá e farinha de trigo em proporções iguais). As colmeias do tratamento 2 não receberam o substituto de pólen, tendo como único alimento o pólen que encontravam na natureza. As colmeias alimentadas apresentaram diferença significativa de 93,5 por cento de viabilidade de sobrevivência de cria em relação às não alimentadas, que apresentaram 80,4 por cento de sobrevivência. A frequência de pólen S. adstringens nos coletores de pólen, no tratamento 1, foi 0,21. Entretanto, no Tratamento 2, foi de 4,38, indicando que as colmeias que não se alimentaram com o substituto apresentaram maior frequência do pólen dessa planta, quando comparadas com as que dispunham da dieta artificial. Esse manejo sugere que a oferta do substituto de pólen, antes e durante a florada do Stryphnodendron adstringens, é importante na redução dos efeitos da cria ensacada brasileira em enxames de abelhas africanizadas.

Brazilian sac brood is one of the worst diseases of Apis mellifera L. mainly in southeast Brazil. This disease affects the larval development after having been fed with "barbatimão" pollen (Stryphnodendron polyphyllum and Stryphnodendron adstringens); the workers become intoxicated and die between the prepupae and pupae stages. This study verified the effect of pollen substitute on the reduction of Apis mellifera L. mortality, caused by Brazilian sac brood during Stryphnodendron adstringens flowering. Two treatments were used: in treatment one, colonies received pollen substitute weekly (a blend of a soy flour, maize flour and wheat flour of equal proportions). The hives of treatment 2 didn´t receive the replacement of pollen substitute, receiving only the pollen found in nature. The hives which were fed with the pollen substitute had significant difference of 93.5 percent of brood survival viability when compared to non-fed which had 80.4 percent of survival. The frequency of pollen S. adstringens in pollen traps, in treatment 1, was of 0.21. However, in treatment 2, the frequency was of 4.38, indicating that the hives that were not fed with the substitute showed a higher frequency of pollen of this plant when compared with those who had the artificial diet. The results suggest that supplying with pollen substitute, before and during Stryphnodendron adstringens flowering, is important in reducing the effects of Brazilian sac brood disease.

Seasonal variation, chemical composition and antioxidant activity of Brazilian propolis samples.

Total phenolic contents, antioxidant activity and chemical composition of propolis samples from three localities of Minas Gerais state (southeast Brazil) were determined. Total phenolic contents were determined by the Folin-Ciocalteau method, antioxidant activity was evaluated by DPPH, using BHT as reference, and chemical composition was analyzed by GC/MS. Propolis from Itapecerica and Paula Cândido municipalities were found to have high phenolic contents and pronounced antioxidant activity. From these extracts, 40 substances were identified, among them were simple phenylpropanoids, prenylated phenylpropanoids, sesqui- and diterpenoids. Quantitatively, the main constituent of both samples was allyl-3-prenylcinnamic acid. A sample from Virginópolis municipality had no detectable phenolic substances and contained mainly triterpenoids, the main constituents being α- and ß-amyrins. Methanolic extracts from Itapecerica and Paula Cândido exhibited pronounced scavenging activity towards DPPH, indistinguishable from BHT activity. However, extracts from Virginópolis sample exhibited no antioxidant activity. Total phenolic substances, GC/MS analyses and antioxidant activity of samples from Itapecerica collected monthly over a period of 1 year revealed considerable variation. No correlation was observed between antioxidant activity and either total phenolic contents or contents of artepillin C and other phenolic substances, as assayed by CG/MS analysis.

Saprophytic fungus collection by Africanized bees in Brazil.

Cladosporium sp. collection by bees (Apis mellifera L.) was observed in Brazil at an apiary located in Minas Gerais, during November 10-23, 2005, characterized by high air relative humidity and low availability of food resources (pollen and nectar).The nutritional composition of the fungi pellets presented high protein value, ethereal extract and organic matter.

Analysis of pollen load based on color, physicochemical composition and botanical source.

Pollen load samples from 10 hives of Apis mellifera (L.) were analyzed based on their physicochemical composition and botanical source, considering color as a parameter for quality control. In seven samples it was possible to establish the occurrence of more than 80% of a single pollen type, characterizing them as unifloral but with protein content variation. One of the samples was exclusively composed of saprophytic fungi (Cladosporium sp.). Comparing the mean results of the fungi loads with those of the nutritional components of pollen load, the former presented higher protein, mineral matter and dry matter and lower organic matter, ethereal extract and total carbohydrate values. The monochromatic samples met the physicochemical specifications regulating pollen load quality. The results showed that homogeneous coloration of the pollen load was not found to be a good indication of unifloral pollen, confirming the importance of physicochemical analysis and melissopalynological analysis for characterization of the quality of commercial pollen load.

Analysis of pollen load based on color, physicochemical composition and botanical source

Pollen load samples from 10 hives of Apis mellifera (L.) were analyzed based on their physicochemical composition and botanical source, considering color as a parameter for quality control. In seven samples it was possible to establish the occurrence of more than 80 percent of a single pollen type, characterizing them as unifloral but with protein content variation. One of the samples was exclusively composed of saprophytic fungi (Cladosporium sp.). Comparing the mean results of the fungi loads with those of the nutritional components of pollen load, the former presented higher protein, mineral matter and dry matter and lower organic matter, ethereal extract and total carbohydrate values. The monochromatic samples met the physicochemical specifications regulating pollen load quality. The results showed that homogeneous coloration of the pollen load was not found to be a good indication of unifloral pollen, confirming the importance of physicochemical analysis and melissopalynological analysis for characterization of the quality of commercial pollen load.

Amostras de cargas de pólen de 10 colméias de Apis mellifera (L.) foram analisadas quanto a sua composição físico-química e origem botânica, tomando-se a coloração como parâmetro para o controle de qualidade. Em sete amostras foi possível estabelecer a ocorrência de mais de 80 por cento de um único tipo polínico, caracterizando-as como monoflorais, porém com variações nos valores protéicos. Uma das amostras era composta exclusivamente por fungos saprofíticos (Cladosporium sp.). Comparando-se as bolotas de fungos com os resultados médios dos componentes nutricionais das bolotas de pólen, as primeiras apresentaram maior valor protéico, matéria mineral e matéria seca e menores valores de matéria orgânica, extrato etéreo ecarboidratos totais. As amostras monocromáticas estiveram de acordo com as especificações físico-químicas reguladoras da qualidade de pólen apícola. Os resultados demonstram que a coloração homogênea das cargas de pólen não se apresentou como um bom indicativo de pólen monofloral e confirma a importância das análises físico-químicas e melissopalinológicas para a caracterização da qualidade do pólen apícola a ser comercializado.

Saprophytic fungus collection by africanized bees in Brazil / Coleta de fungos saprofíticos por abelhas africanizadas no Brasil

Cladosporium sp. collection by bees (Apis mellifera L.) was observed in Brazil at an apiary located in Minas Gerais, during November10-23, 2005, characterized by high air relative humidity and low availability of food resources (pollen and nectar).The nutritional composition of the fungi pellets presented high protein value, ethereal extract and organic matter.

A coleta de Cladosporium sp. por abelhas (Apis mellifera L.) foi observada no Brasil em um apiário localizado em Minas Gerais, no período de 10 a 23/11/05, caracterizado pela alta umidade relativa do ar e escassez de recurso alimentar (pólen e néctar). A composição nutricional das bolotas de fungos apresentou alto valor protéico, extrato etéreo e matéria orgânica.

Virus infections in Brazilian honey bees.

This work describes the first molecular-genetic evidence for viruses in Brazilian honey bee samples. Three different bee viruses, Acute bee paralysis virus (ABPV), Black queen cell virus (BQCV), and Deformed wing virus (DWV) were identified during a screening of RNAs from 1920 individual adult bees collected in a region of southeastern Brazil that has recently shown unusual bee declines. ABPV was detected in 27.1% of colony samples, while BQCV and DWV were found in 37% and 20.3%, respectively. These levels are substantially lower than the frequencies found for these viruses in surveys from other parts of the world. We also developed and validated a multiplex RT-PCR assay for the simultaneous detection of ABPV, BQCV, and DWV in Brazil.

Widespread dispersal of the microsporidian Nosema ceranae, an emergent pathogen of the western honey bee, Apis mellifera.

The economically most important honey bee species, Apis mellifera, was formerly considered to be parasitized by one microsporidian, Nosema apis. Recently, [Higes, M., Martín, R., Meana, A., 2006. Nosema ceranae, a new microsporidian parasite in honeybees in Europe, J. Invertebr. Pathol. 92, 93-95] and [Huang, W.-F., Jiang, J.-H., Chen, Y.-W., Wang, C.-H., 2007. A Nosema ceranae isolate from the honeybee Apis mellifera. Apidologie 38, 30-37] used 16S (SSU) rRNA gene sequences to demonstrate the presence of Nosema ceranae in A. mellifera from Spain and Taiwan, respectively. We developed a rapid method to differentiate between N. apis and N. ceranae based on PCR-RFLPs of partial SSU rRNA. The reliability of the method was confirmed by sequencing 29 isolates from across the world (N =9 isolates gave N. apis RFLPs and sequences, N =20 isolates gave N. ceranae RFLPs and sequences; 100% correct classification). We then employed the method to analyze N =115 isolates from across the world. Our data, combined with N =36 additional published sequences demonstrate that (i) N. ceranae most likely jumped host to A. mellifera, probably within the last decade, (ii) that host colonies and individuals may be co-infected by both microsporidia species, and that (iii) N. ceranae is now a parasite of A. mellifera across most of the world. The rapid, long-distance dispersal of N. ceranae is likely due to transport of infected honey bees by commercial or hobbyist beekeepers. We discuss the implications of this emergent pathogen for worldwide beekeeping.

Origin and Chemical Variation of Brazilian Propolis.

Propolis is a hive product containing chiefly beeswax and plant-derived substances such as resin and volatile compounds. Propolis has been used as an antiseptic and wound healer since ancient times and interest for the product has increased recently. Probably few plant species contribute as major resin sources. Green propolis derives mainly from vegetative apices of Baccharis dracunculifolia (alecrim plants). However, wide variation detected in the chemical composition suggests contributions from alternative resin plant sources. Predominant components of the resin of green propolis are cinnamic acids, chiefly compounds bearing prenyl groups. Terpenoid compounds, such as sesqui, di and pentacyclic triterpenoids, have been detected in many, but not all, samples investigated. Propolis research has uncovered potentialities of substances previously isolated from plants and has detected constituents of plant origin that would hardly be known otherwise.

Plant Origin of Green Propolis: Bee Behavior, Plant Anatomy and Chemistry.

Propolis, a honeybee product, has gained popularity as a food and alternative medicine. Its constituents have been shown to exert pharmacological effects, such as anti-microbial, anti-inflammatory and anticancer. Shoot apices of Baccharis dracunculifolia (alecrim plant, Asteraceae) have been pointed out as sources of resin for green propolis. The present work aimed (i) to observe the collecting behavior of bees, (ii) to test the efficacy of histological analysis in studies of propolis botanical origin and (iii) to compare the chemistries of alecrim apices, resin masses and green propolis. Bee behavior was observed, and resin and propolis were microscopically analyzed by inclusion in methacrylate. Ethanol extracts of shoot apices, resin and propolis were analyzed by gas chromatography/mass spectroscopy. Bees cut small fragments from alecrim apices, manipulate and place the resulting mass in the corbiculae. Fragments were detected in propolis and identified as alecrim vestiges by detection of alecrim structures. Prenylated and non-prenylated phenylpropanoids, terpenoids and compounds from other classes were identified. Compounds so far unreported for propolis were identified, including anthracene derivatives. Some compounds were found in propolis and resin mass, but not in shoot apices. Differences were detected between male and female apices and, among apices, resin and propolis. Alecrim apices are resin sources for green propolis. Chemical composition of alecrim apices seems to vary independently of season and phenology. Probably, green propolis composition is more complex and unpredictable than previously assumed.

Curva de sobrevivência de bactérias isoladas do leite de vacas com mastite a três extratos etanólicos de própolis

Estudou-se o efeito de extratos etanólicos de própolis obtidos por álcool 70, 80 e 95%, sobre amostras de Staphy/ococcusaureus e Streptococcus agalactiae isoladas do leite de vacas com mastite. Não houve diferença significativa (p>0,01) naatividade antibacteriana entre os três tipos de extratos etanólicos de própolis estudados. As duas concentrações de extratosetanólicos utilizadas na avaliação da sensibilidade do Staphylococcus aureus, 3,0 e 2,0 mg/ml, inibiram, de maneira semelhante,as três amostras bacterianas testadas. Somente em uma amostra foi observada ação bactericida dos extratos etanólicosde própolis, em ambas as concentrações, a partir de 12 horas de exposição. Nas duas amostras de Streptococcus aga/actiae,observou-se o efeito bactericida da própolis ao final do período de 24 horas de exposição às concentrações de 0,43 e 0,3 mg/ml. Verificou-se que, com dosagens cerca de dez vezes menores que as aplicadas para Staphylococcus aureus, houve umacompleta e irreversível inibição do Streptococcus agalactiae, dentro do período estudado. Estes resultados estimulam oprosseguimento de novas investigações sobre a utilização de extratos de própolis, em veículos adequados, com vistas aotratamento da mastite bovina.

Efeito de antocianina e própolis em diabetes induzida em coelhos / Effects of anthocyanin and propolis in diabetic rabbits

A síndrome clínica da diabetes ‚ caracterizada pela redução da capacidade de metabolização de carboidratos e gorduras, resultando em aumento dos níveis séricos de glicose (hiperglicemia) e lipídios (hiperlipidemia), acarretando em degeneração vascular prematura. O objetivo do presente trabalho foi testar os efeitos da antocianina e do própolis ministrados nas doses de 20mg e 150mg, respectivamente, em coelhos diabéticos para a verificação dos efeitos sobre os níveis de glicose e triacilglicerol. Os grupos experimentais de coelhos estudados foram: Grupo 1- grupo controle que somente recebeu ração; Grupo 2- grupo diabético que recebeu ração mais aloxano; Grupo 3- grupo diabético que recebeu ração, aloxano e 1 c psula de antocianina (20mg) diariamente; Grupo 4- grupo diabético que recebeu ração, aloxano e 1 c psula de própolis (150mg) diariamente. Os Grupos 3 e 4 foram submetidos a vinte e oito dias de tratamento, com dosagem semanal dos níveis sanguíneos de glicose e de triacilglicerol. De acordo com os resultados obtidos, pode-se observar que, durante todo o período experimental, a antocianina foi mais eficaz, em induzir a queda dos níveis de glicose, com reduções de 10,78 por cento aos 7 dias, 10,54 por cento aos 14 dias, 17,33 por cento aos 21 dias e 28,09 por cento aos 28 dias. J  o própolis apresentou redução de 22,69 por cento aos 28 dias. Observou-se redução dos percentuais de variação de triacilgliceróis em 22,74 por cento pela antocianina e 22,60 por cento pelo tratamento com própolis aos 28 dias. Ao se compararem os Grupos 3 e 4 com o Grupo 2 (aloxano) durante todo o período experimental, os níveis de triacilgliceróis aumentaram no período de O a 21 dias

Efeito de extratos de própolis verde sobre bactérias patogênicas isoladas do leite de vacas com mastite / Effect of green propolis extracts on patogenic bacteria isolated from milk of cows with mastitis

A sensibilidade, in vitro, de amostras de Staphylococcus aureus, Staphylococcus sp. coagulase negativos, Streptococcus agalactiae e bactérias do grupo dos coliformes, isoladas do leite de vacas com mastite, a diferentes extratos de própolis, na concentraçäo de 100 mg/ml, foi avaliada pela técnica do antibiograma em discos de papel de filtro com sobrecamada de meio de cultura. Os resultados mostraram que o extrato etanólico de própolis comercial, os extratos etanólico e, em menor proporçäo, o metanólico inibiram o crescimento das amostras de bactérias Gram-positivas, Staphylococcus aureus, Staphylococcus sp. coagulase negativos e Streptococcus agalactiae. Os extratos obtidos através da água, do acetato de etila e do clorofórmio näo inibiram nenhuma amostra bacteriana, assim como os veículos etanol e metanol puros utilizados como controle. A bactéria Gram-negativa testada, do tipo coliforme, näo apresentou sensibilidade a nenhum dos extratos. Verificaram-se diferenças significativas (p < 0,05) na sensibilidade aos extratos entre amostras bacterianas de uma mesma espécie, mas de origens diferentes. Nas amostras de Streptococcus agalactiae, os diâmetros dos halos de inibiçäo do crescimento bacteriano ao redor do disco foram maiores que aqueles observados para as amostras de Staphylococcus aureus e Staphylococcus sp. coagulase negativos. Todos estes resultados estimulam o prosseguimento de novas pesquisas sobre a utilizaçäo de extratos de própolis, em veículos adequados, com vistas ao tratamento da mastite bovina