Ureases (EC 3.5.1.5) são metaloenzimas dependentes de Ni2+que hidrolisam ureia para produzir amônia e CO2. Estas enzimas são encontradas em fungos, bactérias e plantas, compartilhando estruturas similares. Nosso grupo vem demonstrando que ureases possuem propriedades biológicas independentes da atividade ureolítica que potencialmente contribuem para a patogenicidade de micro-organismoss produtores de urease. A presença de urease em bactérias patogênicas (p.e. Helicobacter pylori, Proteus mirabilis) está correlacionada com a patogênese em algumas doenças humanas. Alguns fungos de importância médica também são produtores de urease entre eles Cryptococcus neoformans, Coccidioides immitis, Histoplasma capsulatum, Sporothrix schenckii. Cryptococcus gattii é um dos agentes etiológicos da criptococose em humanos e animais e acomete mais frequentemente indivíduos imunocompetentes. A maioria dos isolados produzem urease e vários autores sugerem que a liberação de amônia pela atividade da urease de Cryptococcus tem papel importante na patogenia da doença favorecendo uma maior permeabilidade que proporciona a transmigração das leveduras para o sistema nervoso central (SNC). No presente trabalho, para analisar o potencial de virulência da urease de C. gattii foram construídos mutantes com inativação do gene estrutural URE (ure1) e dos genes que codificam as proteínas acessórias (URED, UREF – ure4 e ure6 respectivamente). Assim como já descrito para H. pylori, a urease de C. gattii desempenha papel importante na virulência independente da atividade enzimática. Esta função ocorre anterior a invasão do SNC diminuindo a multiplicação da levedura em macrófagos, aumentando a carga infecciosa no sangue e atenuando a mortalidade tanto no mutante ure1Δ como no mutante ure6Δ em camundongos infectados por via intranasal. / Ureases (EC 3.5.1.5) are metalloenzymes Ni2+ dependents that hydrolyze urea to produce ammonia and CO2. These enzymes are found in fungi, bacteria and plants, show very similar structures. Our group has shown that plant and bacterial ureases display biological properties independent of their ureolytic activity that may contribute to the pathogenesis of urease-producing microrganisms. The presence of urease in pathogenic bacteria (e.g. Helicobacter pylori, Proteus mirabilis) strongly correlates with pathogenesis in some human diseases. Many medically important fungi also produce urease, among which are Cryptococcus neoformans, Coccidioides immitis, Histoplasma capsulatum, Sporothrix schenckii. Cryptococcus gattii is one of the etiologic agent that causes criptococcosis in human and animals, which often affects immunocompromised patients. The majority of clinical isolates produce large amounts of urease, and several authors suggest that the ammonia realease from urease activity might introduce a local damage of the endothelium, thus increasing permeability which provides yeast transmigration to central nervous system (CNS). To analyse virulence potential of C. gattii urease, mutants inactivating structural URE (ure1) gene and coding genes for accessory proteins required to assemble the Ni2+-containing active site (URED, UREF – ure4 and ure6 respectively ). As already described to H. pylori urease, the C. gattii urease play important roles in virulence independent of ureolytic activity before CNS invasion, reducing yeast multiplication in macrophage, decreasing blood burden and also attenuating mortality either ure1Δ and accessory ure6Δ mutant in mice intranasal infection.

Made available in DSpace on 2014-06-11T19:27:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-23Bitstream added on 2014-06-13T19:56:02Z : No. of bitstreams: 1 paiva_jb_me_jabo.pdf: 902974 bytes, checksum: d01d6993a37d78f84e978b7b9def9ecd (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Salmonella enterica sorotipo Typhimurium sintetiza cobalamina (Vitamina B12) apenas sobre condições anaeróbicas. Dois porcento do genoma da S. Typhimurium é dedicado a reações dependentes de vitamina B12 como cofator, sua síntese e absorção. Neste estudo nós preparamos mutantes de Salmonella sorotipos Enteritidis, Gallinarum e Pullorum duplo defectivos na biossintese de cobalamina, cepas ΔcobSΔcbiA. A virulência destes mutantes foi comparada com as respectivas cepas selvagens e, nenhuma deficiência na capacidade de causar doença foi observada para as cepas de S. Enteritidis ΔcobSΔcbiA e S. Pullorum ΔcobSΔcbiA. S. Gallinarum ΔcobSΔcbiA por sua vez, mostrou atenuação total. Posteriormente nós testamos a produção de B12 pelas cepas mutantes e selvagens já descritas, e incluímos neste estudo a cepa de S. Typhimurium ΔcobSΔcbiA, e sua respectiva cepa selvagem. Todas as cepas mutantes não tiveram produção de B12 detectada. As cepas selvagens mostraram produção de vitamina B12 em ambos os ensaios utilizados, com exceção da S. Gallinarum que não apresentou produção de cobalamina in vitro. Como conclusão, a produção de vitamina B12 in vitro diferiu entre os sorotipos de Salmonella testados, a deleção dos genes cbiA e cobS produziu alteração na relação parasita hospedeiro em diferentes níveis entre os sorotipos de Salmonella estudados, sendo que esta foi muito maior entre o sorotipo Gallinarum e as aves. / Salmonella enterica serovar Typhimurium only synthesizes cobalamin (Vitamin B12) during anaerobiosis. Two-percent of the S. Typhimurium genome is devoted to the synthesis and uptake of Vitamin B12 and to B12-dependent reactions. In order to understand the requirement from cobalamin synthesis better, we constructed Salmonella serovar Gallinarum, Salmonella serovar Enteritidis and Salmonella serovar Pullorum mutants that are double-defective in cobalamin biosynthesis (ΔcobSΔcbiA). We compared the virulence of these mutants to that of their respective wild type strains and found no impairment in S. Enteritidis ΔcobSΔcbiA and S. Pullorum ΔcobSΔcbiA ability to cause disease in chickens. S. Gallinarum ΔcobSΔcbiA mutant showed attenuated for chickens. We then assessed B12 production by these mutants and their respective wild type strains, as well as S. Typhimurium ΔcobSΔcbiA, and their respective wild type strain. All mutants were unable to produce detectable B12. B12 was detectable in wild type strains, but, S. Gallinarum demonstrated no in vitro cobalamin production. In conclusion, the production of vitamin B12 in vitro differed across the Salmonella serotypes that were tested. Furthermore, the deletion of the cbiA and cobS genes resulted in an alteration in the relationship between the serotype Gallinarum and the birds more stronger than did to the others serotypes.

Made available in DSpace on 2015-03-26T13:51:47Z (GMT). No. of bitstreams: 1 01 - capa_abstract.pdf: 124558 bytes, checksum: bad84451063512c6789c09aabfdf0fd7 (MD5) Previous issue date: 2009-02-17 / Mutants of Lactobacillus delbrueckii UFV H2b20 were isolated after treatment with ultra violet light, acridine orange, or ethyl methane sulfonate. After the mutagenic treatments, ten colonies were picked randomly from each treatment and were the mutants characterized. Specific growth rate (µ) and survival to successive freeze-thaw cycles were assessed for each isolate along with milk acidification rate and survival to storage at – 20 ºC with different crioprotective agents. Among all 30 isolates, mutants MUV9, MAC6, and MEMS2 displayed higher µ values and better survival after repeated freezethaw cycles. Survival of the mutant strains after 15 days at – 20 ºC, both in the presence and the absence of cryoprotective, was better than survival of the wild type. Reconstituted non fat milk (10 %) proved to be a better cryoprotective agent than saccharose and monosodium glutamate for storage at – 20 ºC. Survival rates were higher for mutants MAC6 and MEMS2, after 15 days at – 20 ºC. Cold shock, at 10 ºC for four-hours, and heat shock, 50 ºC for 30 minutes, enhanced survival of the mutant strains and also of the parental strain as measured after 70 days at – 20 ºC. Cold shock response allowed better survival to all the strains, mutant and parental, when compared to the heat shock. The results reported here show that strain development of L. delbrueckii UFV H2b20 for technological purposes can be achieved by a classical genetic mutation. / Mutantes de Lactobacillus delbrueckii UFV H2b20 foram isolados após procedimento de mutagênese com luz ultravioleta, acridina laranja e etil metano sulfonato. Após este procedimento, foram selecionadas, aleatoriamente, 10 colônias em cada tratamento para serem caracterizadas quanto à velocidade específica de crescimento (µ) e sobrevivência a três ciclos de congelamento e descongelamento. Dentre o total de 30 isolados selecionados os mutantes MUV9, MAC6e MEMS2, sendo estes os que apresentaram maior µ e tolerância a repetidos ciclos de congelamento e descongelamento. A sobrevivência das estirpes mutantes após 15 dias de estocagem a – 20 ºC na ausência e na presença de substâncias crioprotetoras foi maior do que a da estirpe selvagem. Dentre as substâncias crioprotetoras utilizadas, o leite desnatado reconstituído a 10 % foi o que conferiu melhor proteção durante a estocagem a – 20 ºC. Após 15 dias de estocagem a – 20 ºC, os mutantes MAC6 e MEMS2 foram os que apresentaram maior sobrevivência. O choque frio, 10 ºC por 4 horas e o choque térmico, 50 ºC por 30 minutos aumentaram a sobrevivência das estirpes mutantes e da estirpe parental à estocagem de 70 dias a -20 ºC, sendo que o choque frio permitiu maior sobrevivência ao congelamento as estirpes mutantes e parental do que o choque térmico. Os resultados aqui apresentados estimulam a continuidade do trabalho de melhoramento de L. delbrueckii UFV H2b20 para uso tecnológico.

Conserved residues in protein are crucial for maintaining structure and function, either by direct involvement in chemistry or indirectly, by being essential for folding, stability and oligomerisation and are mostly clustered near active sites. The variability of sequences of the same protein from diverse organisms is a reflection of the selective pressures of evolution. Sequence conservation analysis with 3397 bacterial triosephosphate isomerase (TIM) sequences using Plasmodium falciparum (Pf) TIM as template, showed full conservation of ten residues, K12, T75, H95, E97, C126, E165, P166, G209, G210 and G228. The integrity of the enzyme active site, which lies near the dimer interface, makes TIM an obligatory dimer. Attempts to engineer active monomeric TIM have not been successful. The present study assesses the effects of mutations at fully conserved position 75 (Thr) and the highly conserved position 64 (Q: 3011, E: 383) near the dimer interface, using the recombinant Plasmodial enzyme. Residue 64, Gln in Pf, and T75 interact with the catalytic E97 and K12, respectively. Preliminary analysis of available crystal structures showed that Gln 64 takes part in a single intersubunit interaction and maintains the obligatory strained backbone angles of the catalytic K12 residue, while Thr 75 is involved in four intersusunit hydrogen bond interactions. This led to the hypothesis that mostly, Gln at position 64 is crucial for enzyme activity and Thr at position 75 for the integrity of the dimer. Biophysical and kinetic data are reported for four T75 (T75S/V/C/N) and two Q64 (Q64N/E) mutants. The major findings revealed that the mutations at position 64 have a significant effect on dimer integrity with a 1000 fold increase in the dimer dissociation constant compared to the wild type enzyme, while dimer stability was unimpaired for the T75 mutants. Concentration dependence of activity yielded an estimate of dimer dissociation constant (Kd) values (Q64N 73.7±9.2 nM and Q64E 44.6±8.4 nM). Enzyme activity values of the T75 mutants are comparable to the wild type, except for T75N which shows a 4-fold drop in activity. All four T75 mutants show a dramatic fall in activity between 35 °-45 °C. Crystal structure determination of the T75S/V/N mutant offers insights into the variation in local interactions with T75N showing the largest changes. These results were unanticipated emphasising the uncertainties involved in inferring functional and structural role for individual residues based only on analysis of interactions observed in crystal structures. Nanospray ionisation mass spectrometric studies has also been used to probe the oligomeric properties of the three mutant proteins Q64N, Q64E and T75S and the wild type enzyme in the gas phase. The gas phase distributions of dimeric and monomeric species have been examined under a wild range of collision energies (40 – 160 eV). The order in the gas phase, PfTIM wild type > T75S > Q64E ~ Q64N, together with the solution phase experiments described above establish the importance of Q64 and T75 in influencing stability and activity. Inhibition studies with a 27 residue synthetic dimer interface peptide and the Q64 mutants establish that the interaction between the protein and the peptide was facilitated in the case of monomeric species.

Ureases (EC 3.5.1.5) são metaloenzimas dependentes de Ni2+que hidrolisam ureia para produzir amônia e CO2. Estas enzimas são encontradas em fungos, bactérias e plantas, compartilhando estruturas similares. Nosso grupo vem demonstrando que ureases possuem propriedades biológicas independentes da atividade ureolítica que potencialmente contribuem para a patogenicidade de micro-organismoss produtores de urease. A presença de urease em bactérias patogênicas (p.e. Helicobacter pylori, Proteus mirabilis) está correlacionada com a patogênese em algumas doenças humanas. Alguns fungos de importância médica também são produtores de urease entre eles Cryptococcus neoformans, Coccidioides immitis, Histoplasma capsulatum, Sporothrix schenckii. Cryptococcus gattii é um dos agentes etiológicos da criptococose em humanos e animais e acomete mais frequentemente indivíduos imunocompetentes. A maioria dos isolados produzem urease e vários autores sugerem que a liberação de amônia pela atividade da urease de Cryptococcus tem papel importante na patogenia da doença favorecendo uma maior permeabilidade que proporciona a transmigração das leveduras para o sistema nervoso central (SNC). No presente trabalho, para analisar o potencial de virulência da urease de C. gattii foram construídos mutantes com inativação do gene estrutural URE (ure1) e dos genes que codificam as proteínas acessórias (URED, UREF – ure4 e ure6 respectivamente). Assim como já descrito para H. pylori, a urease de C. gattii desempenha papel importante na virulência independente da atividade enzimática. Esta função ocorre anterior a invasão do SNC diminuindo a multiplicação da levedura em macrófagos, aumentando a carga infecciosa no sangue e atenuando a mortalidade tanto no mutante ure1Δ como no mutante ure6Δ em camundongos infectados por via intranasal. / Ureases (EC 3.5.1.5) are metalloenzymes Ni2+ dependents that hydrolyze urea to produce ammonia and CO2. These enzymes are found in fungi, bacteria and plants, show very similar structures. Our group has shown that plant and bacterial ureases display biological properties independent of their ureolytic activity that may contribute to the pathogenesis of urease-producing microrganisms. The presence of urease in pathogenic bacteria (e.g. Helicobacter pylori, Proteus mirabilis) strongly correlates with pathogenesis in some human diseases. Many medically important fungi also produce urease, among which are Cryptococcus neoformans, Coccidioides immitis, Histoplasma capsulatum, Sporothrix schenckii. Cryptococcus gattii is one of the etiologic agent that causes criptococcosis in human and animals, which often affects immunocompromised patients. The majority of clinical isolates produce large amounts of urease, and several authors suggest that the ammonia realease from urease activity might introduce a local damage of the endothelium, thus increasing permeability which provides yeast transmigration to central nervous system (CNS). To analyse virulence potential of C. gattii urease, mutants inactivating structural URE (ure1) gene and coding genes for accessory proteins required to assemble the Ni2+-containing active site (URED, UREF – ure4 and ure6 respectively ). As already described to H. pylori urease, the C. gattii urease play important roles in virulence independent of ureolytic activity before CNS invasion, reducing yeast multiplication in macrophage, decreasing blood burden and also attenuating mortality either ure1Δ and accessory ure6Δ mutant in mice intranasal infection.

No description available.

Ureases (EC 3.5.1.5) são metaloenzimas dependentes de Ni2+que hidrolisam ureia para produzir amônia e CO2. Estas enzimas são encontradas em fungos, bactérias e plantas, compartilhando estruturas similares. Nosso grupo vem demonstrando que ureases possuem propriedades biológicas independentes da atividade ureolítica que potencialmente contribuem para a patogenicidade de micro-organismoss produtores de urease. A presença de urease em bactérias patogênicas (p.e. Helicobacter pylori, Proteus mirabilis) está correlacionada com a patogênese em algumas doenças humanas. Alguns fungos de importância médica também são produtores de urease entre eles Cryptococcus neoformans, Coccidioides immitis, Histoplasma capsulatum, Sporothrix schenckii. Cryptococcus gattii é um dos agentes etiológicos da criptococose em humanos e animais e acomete mais frequentemente indivíduos imunocompetentes. A maioria dos isolados produzem urease e vários autores sugerem que a liberação de amônia pela atividade da urease de Cryptococcus tem papel importante na patogenia da doença favorecendo uma maior permeabilidade que proporciona a transmigração das leveduras para o sistema nervoso central (SNC). No presente trabalho, para analisar o potencial de virulência da urease de C. gattii foram construídos mutantes com inativação do gene estrutural URE (ure1) e dos genes que codificam as proteínas acessórias (URED, UREF – ure4 e ure6 respectivamente). Assim como já descrito para H. pylori, a urease de C. gattii desempenha papel importante na virulência independente da atividade enzimática. Esta função ocorre anterior a invasão do SNC diminuindo a multiplicação da levedura em macrófagos, aumentando a carga infecciosa no sangue e atenuando a mortalidade tanto no mutante ure1Δ como no mutante ure6Δ em camundongos infectados por via intranasal. / Ureases (EC 3.5.1.5) are metalloenzymes Ni2+ dependents that hydrolyze urea to produce ammonia and CO2. These enzymes are found in fungi, bacteria and plants, show very similar structures. Our group has shown that plant and bacterial ureases display biological properties independent of their ureolytic activity that may contribute to the pathogenesis of urease-producing microrganisms. The presence of urease in pathogenic bacteria (e.g. Helicobacter pylori, Proteus mirabilis) strongly correlates with pathogenesis in some human diseases. Many medically important fungi also produce urease, among which are Cryptococcus neoformans, Coccidioides immitis, Histoplasma capsulatum, Sporothrix schenckii. Cryptococcus gattii is one of the etiologic agent that causes criptococcosis in human and animals, which often affects immunocompromised patients. The majority of clinical isolates produce large amounts of urease, and several authors suggest that the ammonia realease from urease activity might introduce a local damage of the endothelium, thus increasing permeability which provides yeast transmigration to central nervous system (CNS). To analyse virulence potential of C. gattii urease, mutants inactivating structural URE (ure1) gene and coding genes for accessory proteins required to assemble the Ni2+-containing active site (URED, UREF – ure4 and ure6 respectively ). As already described to H. pylori urease, the C. gattii urease play important roles in virulence independent of ureolytic activity before CNS invasion, reducing yeast multiplication in macrophage, decreasing blood burden and also attenuating mortality either ure1Δ and accessory ure6Δ mutant in mice intranasal infection.

The circadian clock regulates a wide range of biological processes, allowing plants to be prepared for predictable daily diurnal changes in environmental cues such as light and temperature. Recent studies have suggested that the circadian clock may also control plant immunity. The exact nature of the interaction between the circadian clock and plant pathogens remains unknown. Our focus in this study is on the elucidation of the role of the biological clock in plant immunity against the necrotrophic pathogen to Botrytis cinerea. In order to do this we tested the level of susceptibility to B. cinerea in Arabidopsis thaliana wild type and transgenic plants: toc1, cca1/lhy, cca1/toc1, lhy/toc1, cca1/lhy/toc1, GLK1 OE, GLK2 OE, glk1, glk2, and glk1/glk2. We demonstrated that the time of infection plays a role in susceptibility to B. cinerea. Specifically, we found that plants are more susceptible to infection in the subjective morning. We also found that genetic mutations in core clock components or in GLK genes leads to changes in susceptibility to B. cinerea. Our data suggests that clock genes are not solely responsible for plant immune responses to B. cinerea but rather the ways in which the biological clock system regulates outcome pathways. Furthermore, when we entrain the biological clock by changing the photoperiod (day length) in normal earth conditions LD 24h and SD 24h, we observed that short day plants had higher susceptibility to B. cinerea than long day plants. In addition, when we entrain the biological clock in different photoperiods, the LD 30h photoperiod plants displayed similar responses as those in the SD 24h photoperiod. The data indicates that day length is not responsible for the control of plant immunity; it is the ability of light to entrain the biological clock that is important. Together, the data strongly support the conclusion that the circadian clock plays a role in plant defense regulation.

In this thesis, we specifically focus on testing non-functional proprieties. We target the Worst-Case Execution Time (WCET), which is very important for real-time tasks. This thesis applies the concept of targeted mutation, where the mutations are applied to the parts of the code that are most likely to significantly affect the execution time. Moreover, program slicing is used to direct the mutations to the code parts that are likely to have the strongest influence on execution time. The main contribution of the thesis is to implement the method for the experimental evaluation of the targeted mutation testing. This thesis confirms the relevance of the concept of targeted mutation by showing that targeted mutation enables the design of effective test suites for WCET estimation and improves the efficiency of this process by reducing the number of mutants. To experiment the method, we used two C benchmarks from Mälardalen University benchmarks, The first benchmark is Janne-complex code, it consists of 20 line of code and 10 test cases, This benchmark contains two loops, where the inner loop max number of iterations depends on the outer loop current iterations. The results correspond to something Janne flow-analysis should produce. Where the second benchmark is Ludcmp, it consists of 50 lines of code and 9 test cases. This benchmark is a simultaneous linear equation by LU decomposition; it contains two arrays for input and one array for output. However, the number of equations determined by the variable (n). However, both benchmarks LOC decreased after slicing, and each test case applied ten times against each mutant to eliminate the effect of cache and other applications currently running since our experiments depend on estimation of the WCET. The thesis confirms the relevance of the concept of targeted mutation by showing that targeted mutation (i) encourages the design of effective test suites for WCET estimation and (ii) improves the efficiency of this process by reducing the number of mutants.

Objective: The aim of this study was to evaluate the antibacterial and cytotoxic effect of the methanol extract of the seed and pulp of Myrciaria dubia (camu camu) against Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC 10556). Materials and Methods: For the present in vitro experimental study two methanolic extracts were prepared from the seed and pulp of Myrciaria dubia (camu camu) to be tested against Streptococcus mutans and Streptococcus sanguinis. Ten independents tests were prepared for each type of extract, using Clorhexidine at 0.12% solution as a positive control. The method used was agar diffusion test preparing wells with the experimental solutions cultivated in anaerobic conditions for 48 hours at 37°C, after this time the growth inhibition halo was analysed in millimeters using a vernier. Meanwhile, the Minimum Inhibitory Concentration (MIC) and the cytotoxic effect (CC50) over Jurkat T cell line was found. Results: The methanolic seed extract had more antibacterial effect over Streptococcus mutans with an inhibitory halo of 21.36mm ± 6.35, while the pulp had 16.20mm ± 2.08. For the Streptococcus sanguinis group the inhibitory halo were 19.21mm ± 5.18 and 19.34mm ± 2.90 for the methanolic seed and pulp extract respectively. The MIC for the pulp extract was 125µg/ml for both strains, whereas for the seed antibacterial activity was observed even at low concentrations. Finally the CC50 for the seed extract was at a higher concentration than 800 µg/ml and 524.37µg/ml for the pulp exactract. Conclusions: The methanolic seed and pulp extract of Myrciaria dubia (camu camu) had antibacterial effect against Streptococcus mutans and Streptococcus sanguinis. These extracts were not cytotoxic. / Objetivo: evaluar in vitro el efecto antibacteriano y citotóxico del extracto metanólico de semilla y pulpa de la Myrciaria dubia (camu camu) sobre cepas de Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC 10556). Materiales y métodos: el estudio fue experimental in vitro. Se utilizaron los extractos metanólicos de la semilla y pulpa de Myrciaria dubia (camu camu) sobre las cepas de Streptococcus mutans y Streptococcus sanguinis. Para cada extracto se realizaron 10 pruebas independientes y como control positivo se utilizó la Clorhexidina al 0.12%. Se utilizó el método de difusión en agar con pocillos con las soluciones experimentales en condiciones de anaerobiosis por 48 horas a 37°C, para luego proceder a la lectura de los diámetros del halo de inhibición con un vernier. Asimismo, se halló la concentración mínima inhibitoria (CMI) de los extractos y se determinó el efecto citotóxico (CC50) sobre la línea celular Jurkat. Resultados: el extracto metanólico de la semilla tuvo mayor efecto antibacteriano sobre el Streptococcus mutans con halos de 21.36mm ± 6.35, mientras que la pulpa tuvo 16.20mm ± 2.08. Para el grupo de Streptococcus sanguinis, se observó que los halos de inhibición fueron de 19.21mm ± 5.18 y 19.34mm ± 2.90 para los extractos de semilla y pulpa respectivamente. La CMI del extracto de la pulpa se encontró en la concentración de 125µg/ml para ambas cepas, mientras que para el caso de la semilla se pudo observar actividad antibacteriana aún en bajas concentraciones. Finalmente, la CC50 del extracto de la semilla fue en una concentración mayor a 800 µg/ml y de la pulpa fue 524.37µg/ml. Conclusiones: se determinó que existe efecto antibacteriano del extracto metanólico de la semilla y pulpa de la Myrciaria dubia (camu camu) sobre cepas de Streptococcus mutans y Streptococcus sanguinis. Los extractos metánolicos de este fruto no fueron citotóxicos. / Tesis