The Dof (DNA-binding with one finger) proteins are a class of plant-specific transcription factors that can trigger several processes involved in plant growth and development, as well as in stress responses. Here, we ...The Dof (DNA-binding with one finger) proteins are a class of plant-specific transcription factors that can trigger several processes involved in plant growth and development, as well as in stress responses. Here, we performed a systematic bioinformatics analysis to characterize all Dof genes in common bean, which included analysis of the genome sequence, conserved protein domains, chromosomal locations, subcellular locations, phylogenetic relationships, gene duplications, and gene expression profiles in different tissues. Bioinformatics analysis revealed 36 putative genes related to PvDof that were classified into seven subfamilies (A, B1, B2, C1, C2, D1, and, D2) by comparative phylogenetic analysis. Based on our genome duplication analysis, a total of 36 genes were found to be distributed on all 11 chromosomes, and they expanded through gene duplication in tandem, suggesting the involvement of segmental duplication events in the evolutionary process. Synteny events and phylogenetic comparisons of the Dof proteins of common bean with those of A. thaliana, O. sativa, and G. max L. led to the identification of several orthologous and paralogous genes, which provided further insight into the diversity of the evolutionary characteristics of genes of this family in other plant species. Expression profiles revealed that most of the PvDof genes were expressed in different tissues, indicating that PvDof genes may be involved in various physiological functions during plant development. The results of this study provide additional information and potential biotechnological resources for further understanding the molecular basis of this gene family and consequently improvement of common bean crops.展开更多
Background: Adolescents are disproportionally affected by sexually transmitted infections (STI). Chlamydia trachomatis (CT) and Trichomonas vaginalis (TV) are the most frequent curable STI in adolescents, causing seri...Background: Adolescents are disproportionally affected by sexually transmitted infections (STI). Chlamydia trachomatis (CT) and Trichomonas vaginalis (TV) are the most frequent curable STI in adolescents, causing serious consequences for their reproductive health. Therefore, we aimed to determine the prevalence and incidence of CT and TV, as well as their risk factors in pregnant adolescents from Belém, northern Brazilian Amazon. Methods: This prospective study enrolled 199 adolescents up to 20 weeks of pregnancy. They were scheduled for follow-up visit between 28 and 29 weeks of pregnancy. Sociodemographic and behavioral data were obtained by interview. Cervicovaginal samples were taken to test for TV, CT, Neisseria gonorrhoeae and bacterial vaginosis. Univariate and multivariate analyses were performed to test the association of prevalent/incident CT and TV with the variables. Results: Prevalence of cervical CT infection was 33.7% (n = 67/ 199), and for trichomoniasis it was 4.0% (n = 8/199). Cervical ectopy increased the risk for prevalent CT (OR, 1.93;95% CI, 1.01 - 3.70), while having treated vaginal discharge in the past (OR, 0.51;95% CI, 0.26 - 0.98) and being married (OR, 0.10;95% CI, 0.01 - 0.83) were protective against current CT and TV, respectively. Among the 95 (47.7%) adolescents who completed follow-up, 15 cases of incident CT were identified. Incident CT was associated with having a formal or informal job (OR, 28.4;95% CI, 2.1 - 391.6) and bacterial vaginosis treatment at the baseline (OR, 0.08;95% CI, 0.01 - 0.69). Conclusion: Prevalence and incidence rates of TV and CT are high in this population devoid of STI routine screening. Treatment of bacterial vaginosis may benefit this population by reducing risk for CT acquisition.展开更多
<strong>Introduction:</strong> Simultaneous exposure to certain chemical agents and noise may cause synergistic, additive or potentiating effects on the auditory and vestibular system. However, there is st...<strong>Introduction:</strong> Simultaneous exposure to certain chemical agents and noise may cause synergistic, additive or potentiating effects on the auditory and vestibular system. However, there is still a lack of studies investigating simultaneous exposure to pesticides and noise in the vestibular system. <strong>Purpose: </strong>To analyze the findings of the vestibular evaluation of endemic diseases combat agents when simultaneously exposed to pesticides and noise. <strong>Method: </strong>Thirty-three male pesticide-exposed and noise-fighting endemic diseases combat agents participated in the study. The age range was 48 to 67 years (mean = 56 years). All participants underwent vestibular examinations, such as positional nystagmus research, spontaneous nystagmus with open and closed eyes, semi-spontaneous nystagmus, optokinetic nystagmus, pendular screening, per rotatory, caloric tests and tonal audiometry. Data were analyzed by descriptive statistics. <strong>Results: </strong>Altered exams were presented in 36.4% of the cases. There was no statistically significant relationship between pesticide handling time and test results (p = 0.2825). The results of pure tone audiometry correlated significantly (p = 0.0494) with the vestibular exams, as participants who presented with worse hearing thresholds at the frequency of 4000 Hz in the right ear also presented altered results in the vestibular exam.<strong> Conclusion: </strong>The present study concluded that more than 1/3 of the studied population presented with vestibular dysfunction, which was related to anterior and posterior labyrinth alteration (Cochlear-Vestibular Syndrome). No central vestibular alteration was noted in this population.展开更多
The aim of this study was to investigate the level of evolutionary divergence among five isofemale lineages of Metopolophium dirhodum Walker (Hemiptera: Aphididae) using sequences of the Internal Transcribed Spacer (I...The aim of this study was to investigate the level of evolutionary divergence among five isofemale lineages of Metopolophium dirhodum Walker (Hemiptera: Aphididae) using sequences of the Internal Transcribed Spacer (ITS) of ribosomal DNA (rDNA). These isofemalelineages were derived from parthenogenetic females, previously genetically characterized by having strong association of RAPD (Random Amplified Polymorphic DNA) molecular markers and host plant preference. Out of 25 sequences, only 17 containing ITS2 (the second spacer) were used for analysis due to their quality. Within 250 nucleotide sites originated by multiple alignments, 10.4% were variable, with the predominance of indels over substitutions. The average of nucleotide diversity (π) within isofemale lineages was similar to the diversity found among all isofemale lineages. The topology inferred by the Neighbor-Joining method showed that no evolutionary divergence inferred by ITS2 sequences among isofemale lineages typified by RAPD could be associated with host preference. The ITS2 sequence differences found within lineages and their causes are discussed.展开更多
Objective:To evaluate the frequency of anti-Toxocara spp.antibodies in an adult healthy population.Methods:The study was performed by interviewing 253 blood donors,from 19 to65 years of age,in a hematological centre i...Objective:To evaluate the frequency of anti-Toxocara spp.antibodies in an adult healthy population.Methods:The study was performed by interviewing 253 blood donors,from 19 to65 years of age,in a hematological centre in Presidente Prudente,S(?)o Paulo,southeast Brazil.A survey was applied to blood donors in order to evaluate the possible factors associated to the presence of antibodies,including individual(gender and age),socioeconomic(scholarship,familial income and sanitary facilities)and habit information(contact with soil,geophagy,onycophagy and intake of raw/undercooked meat)as well as the presence of dogs or cats in the household.ELISA test was run for detection of the anti-Toxocara spp.IgG antibodies.Bivariate analysis followed by logistic regression was performed to evaluate the potential risk factors associated to seropositivity.Results:The overall prevalence observed in this study was 8.7%(22/253).Contact with soil was the unique risk factor associated with the presence of antibodies(P=0.0178;0R=3.52;95%CI=1.244-9.995).Conclusions:The results of this study reinforce the necessity in promoting preventive public health measures,even for healthy adult individual,particularly those related to the deworming of pets to avoid the soil contamination,and hygiene education of the population.展开更多
Amniochorion membranes were collected from 25 pregnant women at preterm labor, in the presence or not of Preterm Premature Rupture of Membranes (PPROM) and 27 pregnant women at term in the presence at labor, in order ...Amniochorion membranes were collected from 25 pregnant women at preterm labor, in the presence or not of Preterm Premature Rupture of Membranes (PPROM) and 27 pregnant women at term in the presence at labor, in order to quantify the expression and to evaluate the immunoreactivity of human beta defensins (HBD)1, HBD2, HBD3 and HBD4 in amniochorion membranes from pregnancies complicated by spontaneous prematurity. The HBDs were evaluated by immunohistochemistry, real time quantitative PCR and ELISA. Statistical analyses were performed using Chi-squared and Mann Whitney tests. There was no significant difference in HBDs expression between study and control groups: HBD1 (Md = 0.62 (0.0 - 105.0) vs Md = 0.80 (0.02 - 25.0);p = 0.85), HBD2 (Md = 0.17 (0.0 - 5.2) vs Md = 0.0 (0.0 - 43.2);p = 0.16), HBD3 (Md = 0.11 (0.0 - 140.5) vs Md = 0.06 (0.0 - 972.1);p = 0.91). Also, HBD1, HBD2 and HBD3 protein expression was not significant different between the groups: HBD1 (1.32 pg/mL (0.0 - 1.85) vs 1.08 pg/mL (0.04 - 2.22);p = 0.67), HBD2 (0.00 pg/mL (0.0 - 1.74) vs 0.02 pg/mL (0.0 - 1.24);p = 0.69), HBD3 (0.04 pg/mL (0.0 - 1.05) vs 0.09 pg/mL (0.0 - 1.05);p = 0.63). The immunoreactivity of HBD1, HBD2 and HBD3 was observed in amnion, chorion and decidua cells from preterm and term pregnancies. Amniochorion membranes are sources of HBD1, HBD2 and HBD3 and their expressions are similar in term and preterm pregnancies.展开更多
Antibiotic resistance represents a widespread problem in milk production.The identification of compounds for a topically applied ointment used in mastitis therapy remains elusive.Compounds from the genus Hymenaea can ...Antibiotic resistance represents a widespread problem in milk production.The identification of compounds for a topically applied ointment used in mastitis therapy remains elusive.Compounds from the genus Hymenaea can be administered in cases of multi-drugresistant Staphylococcus aureus infection for ruminant species,but the protective properties are not well known.Wi this research the aim is verify the protective effects of H.martiana against S.aureus infection in bovine mammary epithelial cell line(MAC-T)and to obtain an antioxidant profile evaluation in vitro.The MAC-T cells were challenged with S.aureus after being exposed to the extract of the H.martiana in the protective assay.For the verification of the viability of the MAC-T cells,the MTT assay was performed,and was used dilutions of the plant extract,starting at 2.5%.The extract of H.martiana was evaluated for antioxidant aspect in different dilutions by FRAP,ORAC and DPPH.A variety of flavonoids(quercetin,luteolin,etc.)have been identified as the main components by using mass spectrometry,reinforcing our in vitro findings that flavonoids,especially quercetin,have a medicinal profile capable of killing mastitis-causing bacteria.An excellent antioxidant pattern was observed in the 2.5%solution;however,membrane integrity in MAC-T cells was compromised.Those findings suggest low dilutions of H.martiana extract has a desirable protective effect from S.aureus pathogenesis.Our in vitro studies can be gleaned upon for further in vivo studies.展开更多
This study investigated the effects of yerba mate consumption, a South American beverage, on cardiac remodeling in rats. For this purpose, 24 male Wistar rats were divided into Control Group (CG) which received filter...This study investigated the effects of yerba mate consumption, a South American beverage, on cardiac remodeling in rats. For this purpose, 24 male Wistar rats were divided into Control Group (CG) which received filtered water and a standard diet, and Yerba Mate Group (YM), 6 g of Ilex paraguariensis in 100 ml water and the same diet, for 30 days. The YM group showed a reduction in final body weight and food consumption without altering weight gain. Regarding cardiac remodeling, the YM group exhibited a decrease in the right ventricle weight/final body weight ratio, suggesting cardiac atrophy, without affecting the atria and left ventricle. There was no change in cardiomyocyte area or nuclear fractal dimension in both groups. However, animals that consumed yerba mate showed increased collagen deposition and a smaller fractal dimension in the left ventricle. The consumption of yerba mate at room temperature for 30 days induced changes in cardiac remodeling, as evidenced by increased collagen deposition and alterations in fractal dimension in the left ventricle.展开更多
Brazilian industry produces huge amounts of tannery sludge as residues,which is often disposed by landfilling or land application.However,consecutive amendment of such composted industrial wastes may cause shifts in s...Brazilian industry produces huge amounts of tannery sludge as residues,which is often disposed by landfilling or land application.However,consecutive amendment of such composted industrial wastes may cause shifts in soil microbial biomass(SMB) and enzyme activity.This study aimed to evaluate SMB and enzyme activity after 3-year consecutive composted tannery sludge(CTS) amendment in tropical sandy soils.Different amounts of CTS(0.0,2.5,5.0,10.0,and 20.0 t ha^(-1)) were applied to a sandy soil.The C and N contents of SMB,basal and substrate-induced respiration,respiratory quotient(qCO_2),and enzyme activities were determined in the soil samples collected after CTS amendment for 60 d at the third year.After 3 years,significant changes were found in soil microbial properties in response to different CTS amounts applied.The organic matter and Cr contents significantly increased with increasing CTS amounts.SMB and soil respiration peaked following amendment with 10.0 and 20.0 t ha-1 of CTS,respectively,while qCO_2was not significantly affected by CTS amendment.However,soil enzyme activity decreased significantly with increasing CTS amounts.Consecutive CTS amendment for 3 years showed inconsistent and contrasting effects on SMB and enzyme activities.The decrease in soil enzyme activities was proportional to a substantial increase in soil Cr concentration,with the latter exceeding the permitted concentrations by more than twofold.Thus,our results suggest that a maximum CTS quantity of 5.0 t ha^(-1) can be applied annually to tropical sandy soil,without causing potential risks to SMB and enzyme activity.展开更多
文摘The Dof (DNA-binding with one finger) proteins are a class of plant-specific transcription factors that can trigger several processes involved in plant growth and development, as well as in stress responses. Here, we performed a systematic bioinformatics analysis to characterize all Dof genes in common bean, which included analysis of the genome sequence, conserved protein domains, chromosomal locations, subcellular locations, phylogenetic relationships, gene duplications, and gene expression profiles in different tissues. Bioinformatics analysis revealed 36 putative genes related to PvDof that were classified into seven subfamilies (A, B1, B2, C1, C2, D1, and, D2) by comparative phylogenetic analysis. Based on our genome duplication analysis, a total of 36 genes were found to be distributed on all 11 chromosomes, and they expanded through gene duplication in tandem, suggesting the involvement of segmental duplication events in the evolutionary process. Synteny events and phylogenetic comparisons of the Dof proteins of common bean with those of A. thaliana, O. sativa, and G. max L. led to the identification of several orthologous and paralogous genes, which provided further insight into the diversity of the evolutionary characteristics of genes of this family in other plant species. Expression profiles revealed that most of the PvDof genes were expressed in different tissues, indicating that PvDof genes may be involved in various physiological functions during plant development. The results of this study provide additional information and potential biotechnological resources for further understanding the molecular basis of this gene family and consequently improvement of common bean crops.
基金This study was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq),Grant#551245/2007-7.
文摘Background: Adolescents are disproportionally affected by sexually transmitted infections (STI). Chlamydia trachomatis (CT) and Trichomonas vaginalis (TV) are the most frequent curable STI in adolescents, causing serious consequences for their reproductive health. Therefore, we aimed to determine the prevalence and incidence of CT and TV, as well as their risk factors in pregnant adolescents from Belém, northern Brazilian Amazon. Methods: This prospective study enrolled 199 adolescents up to 20 weeks of pregnancy. They were scheduled for follow-up visit between 28 and 29 weeks of pregnancy. Sociodemographic and behavioral data were obtained by interview. Cervicovaginal samples were taken to test for TV, CT, Neisseria gonorrhoeae and bacterial vaginosis. Univariate and multivariate analyses were performed to test the association of prevalent/incident CT and TV with the variables. Results: Prevalence of cervical CT infection was 33.7% (n = 67/ 199), and for trichomoniasis it was 4.0% (n = 8/199). Cervical ectopy increased the risk for prevalent CT (OR, 1.93;95% CI, 1.01 - 3.70), while having treated vaginal discharge in the past (OR, 0.51;95% CI, 0.26 - 0.98) and being married (OR, 0.10;95% CI, 0.01 - 0.83) were protective against current CT and TV, respectively. Among the 95 (47.7%) adolescents who completed follow-up, 15 cases of incident CT were identified. Incident CT was associated with having a formal or informal job (OR, 28.4;95% CI, 2.1 - 391.6) and bacterial vaginosis treatment at the baseline (OR, 0.08;95% CI, 0.01 - 0.69). Conclusion: Prevalence and incidence rates of TV and CT are high in this population devoid of STI routine screening. Treatment of bacterial vaginosis may benefit this population by reducing risk for CT acquisition.
文摘<strong>Introduction:</strong> Simultaneous exposure to certain chemical agents and noise may cause synergistic, additive or potentiating effects on the auditory and vestibular system. However, there is still a lack of studies investigating simultaneous exposure to pesticides and noise in the vestibular system. <strong>Purpose: </strong>To analyze the findings of the vestibular evaluation of endemic diseases combat agents when simultaneously exposed to pesticides and noise. <strong>Method: </strong>Thirty-three male pesticide-exposed and noise-fighting endemic diseases combat agents participated in the study. The age range was 48 to 67 years (mean = 56 years). All participants underwent vestibular examinations, such as positional nystagmus research, spontaneous nystagmus with open and closed eyes, semi-spontaneous nystagmus, optokinetic nystagmus, pendular screening, per rotatory, caloric tests and tonal audiometry. Data were analyzed by descriptive statistics. <strong>Results: </strong>Altered exams were presented in 36.4% of the cases. There was no statistically significant relationship between pesticide handling time and test results (p = 0.2825). The results of pure tone audiometry correlated significantly (p = 0.0494) with the vestibular exams, as participants who presented with worse hearing thresholds at the frequency of 4000 Hz in the right ear also presented altered results in the vestibular exam.<strong> Conclusion: </strong>The present study concluded that more than 1/3 of the studied population presented with vestibular dysfunction, which was related to anterior and posterior labyrinth alteration (Cochlear-Vestibular Syndrome). No central vestibular alteration was noted in this population.
文摘The aim of this study was to investigate the level of evolutionary divergence among five isofemale lineages of Metopolophium dirhodum Walker (Hemiptera: Aphididae) using sequences of the Internal Transcribed Spacer (ITS) of ribosomal DNA (rDNA). These isofemalelineages were derived from parthenogenetic females, previously genetically characterized by having strong association of RAPD (Random Amplified Polymorphic DNA) molecular markers and host plant preference. Out of 25 sequences, only 17 containing ITS2 (the second spacer) were used for analysis due to their quality. Within 250 nucleotide sites originated by multiple alignments, 10.4% were variable, with the predominance of indels over substitutions. The average of nucleotide diversity (π) within isofemale lineages was similar to the diversity found among all isofemale lineages. The topology inferred by the Neighbor-Joining method showed that no evolutionary divergence inferred by ITS2 sequences among isofemale lineages typified by RAPD could be associated with host preference. The ITS2 sequence differences found within lineages and their causes are discussed.
基金Supported by Universidade do Oeste Paulista (Unoeste)(Grant No.184/2009)
文摘Objective:To evaluate the frequency of anti-Toxocara spp.antibodies in an adult healthy population.Methods:The study was performed by interviewing 253 blood donors,from 19 to65 years of age,in a hematological centre in Presidente Prudente,S(?)o Paulo,southeast Brazil.A survey was applied to blood donors in order to evaluate the possible factors associated to the presence of antibodies,including individual(gender and age),socioeconomic(scholarship,familial income and sanitary facilities)and habit information(contact with soil,geophagy,onycophagy and intake of raw/undercooked meat)as well as the presence of dogs or cats in the household.ELISA test was run for detection of the anti-Toxocara spp.IgG antibodies.Bivariate analysis followed by logistic regression was performed to evaluate the potential risk factors associated to seropositivity.Results:The overall prevalence observed in this study was 8.7%(22/253).Contact with soil was the unique risk factor associated with the presence of antibodies(P=0.0178;0R=3.52;95%CI=1.244-9.995).Conclusions:The results of this study reinforce the necessity in promoting preventive public health measures,even for healthy adult individual,particularly those related to the deworming of pets to avoid the soil contamination,and hygiene education of the population.
文摘Amniochorion membranes were collected from 25 pregnant women at preterm labor, in the presence or not of Preterm Premature Rupture of Membranes (PPROM) and 27 pregnant women at term in the presence at labor, in order to quantify the expression and to evaluate the immunoreactivity of human beta defensins (HBD)1, HBD2, HBD3 and HBD4 in amniochorion membranes from pregnancies complicated by spontaneous prematurity. The HBDs were evaluated by immunohistochemistry, real time quantitative PCR and ELISA. Statistical analyses were performed using Chi-squared and Mann Whitney tests. There was no significant difference in HBDs expression between study and control groups: HBD1 (Md = 0.62 (0.0 - 105.0) vs Md = 0.80 (0.02 - 25.0);p = 0.85), HBD2 (Md = 0.17 (0.0 - 5.2) vs Md = 0.0 (0.0 - 43.2);p = 0.16), HBD3 (Md = 0.11 (0.0 - 140.5) vs Md = 0.06 (0.0 - 972.1);p = 0.91). Also, HBD1, HBD2 and HBD3 protein expression was not significant different between the groups: HBD1 (1.32 pg/mL (0.0 - 1.85) vs 1.08 pg/mL (0.04 - 2.22);p = 0.67), HBD2 (0.00 pg/mL (0.0 - 1.74) vs 0.02 pg/mL (0.0 - 1.24);p = 0.69), HBD3 (0.04 pg/mL (0.0 - 1.05) vs 0.09 pg/mL (0.0 - 1.05);p = 0.63). The immunoreactivity of HBD1, HBD2 and HBD3 was observed in amnion, chorion and decidua cells from preterm and term pregnancies. Amniochorion membranes are sources of HBD1, HBD2 and HBD3 and their expressions are similar in term and preterm pregnancies.
基金The student was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil(CAPES)with the doctoral scholarship(2017)The student has the support of the scholarship grant number 2017/22041-1,Sao Paulo Research Foundation(FAPESP)+1 种基金The plant analysis is supported by the Facepe Pronem(APQ-0741106/2014)We want to thank Dr.Magna Coroa Lima(UNIVIÇOSA/MG)for providing the bacteria from cases of caprine mastitis used in our study and Dr.Aberlado Silva Júnior(UFV/MG)for the opportunity to use the facilities.
文摘Antibiotic resistance represents a widespread problem in milk production.The identification of compounds for a topically applied ointment used in mastitis therapy remains elusive.Compounds from the genus Hymenaea can be administered in cases of multi-drugresistant Staphylococcus aureus infection for ruminant species,but the protective properties are not well known.Wi this research the aim is verify the protective effects of H.martiana against S.aureus infection in bovine mammary epithelial cell line(MAC-T)and to obtain an antioxidant profile evaluation in vitro.The MAC-T cells were challenged with S.aureus after being exposed to the extract of the H.martiana in the protective assay.For the verification of the viability of the MAC-T cells,the MTT assay was performed,and was used dilutions of the plant extract,starting at 2.5%.The extract of H.martiana was evaluated for antioxidant aspect in different dilutions by FRAP,ORAC and DPPH.A variety of flavonoids(quercetin,luteolin,etc.)have been identified as the main components by using mass spectrometry,reinforcing our in vitro findings that flavonoids,especially quercetin,have a medicinal profile capable of killing mastitis-causing bacteria.An excellent antioxidant pattern was observed in the 2.5%solution;however,membrane integrity in MAC-T cells was compromised.Those findings suggest low dilutions of H.martiana extract has a desirable protective effect from S.aureus pathogenesis.Our in vitro studies can be gleaned upon for further in vivo studies.
文摘This study investigated the effects of yerba mate consumption, a South American beverage, on cardiac remodeling in rats. For this purpose, 24 male Wistar rats were divided into Control Group (CG) which received filtered water and a standard diet, and Yerba Mate Group (YM), 6 g of Ilex paraguariensis in 100 ml water and the same diet, for 30 days. The YM group showed a reduction in final body weight and food consumption without altering weight gain. Regarding cardiac remodeling, the YM group exhibited a decrease in the right ventricle weight/final body weight ratio, suggesting cardiac atrophy, without affecting the atria and left ventricle. There was no change in cardiomyocyte area or nuclear fractal dimension in both groups. However, animals that consumed yerba mate showed increased collagen deposition and a smaller fractal dimension in the left ventricle. The consumption of yerba mate at room temperature for 30 days induced changes in cardiac remodeling, as evidenced by increased collagen deposition and alterations in fractal dimension in the left ventricle.
基金Supported by the Conselho Nacional de Desenvolvimento Cientifico e Tecnológico,Brazil(No.302999/2011-6)the Fundacao de Amparo a Pesquisa do Estado do Piaui,Brazil(No.032/2011)
文摘Brazilian industry produces huge amounts of tannery sludge as residues,which is often disposed by landfilling or land application.However,consecutive amendment of such composted industrial wastes may cause shifts in soil microbial biomass(SMB) and enzyme activity.This study aimed to evaluate SMB and enzyme activity after 3-year consecutive composted tannery sludge(CTS) amendment in tropical sandy soils.Different amounts of CTS(0.0,2.5,5.0,10.0,and 20.0 t ha^(-1)) were applied to a sandy soil.The C and N contents of SMB,basal and substrate-induced respiration,respiratory quotient(qCO_2),and enzyme activities were determined in the soil samples collected after CTS amendment for 60 d at the third year.After 3 years,significant changes were found in soil microbial properties in response to different CTS amounts applied.The organic matter and Cr contents significantly increased with increasing CTS amounts.SMB and soil respiration peaked following amendment with 10.0 and 20.0 t ha-1 of CTS,respectively,while qCO_2was not significantly affected by CTS amendment.However,soil enzyme activity decreased significantly with increasing CTS amounts.Consecutive CTS amendment for 3 years showed inconsistent and contrasting effects on SMB and enzyme activities.The decrease in soil enzyme activities was proportional to a substantial increase in soil Cr concentration,with the latter exceeding the permitted concentrations by more than twofold.Thus,our results suggest that a maximum CTS quantity of 5.0 t ha^(-1) can be applied annually to tropical sandy soil,without causing potential risks to SMB and enzyme activity.