Serological detection of Plasmodium vivax malaria using recombinant proteins corresponding to the 19-kDa C-terminal region of the merozoite surface protein-1

Background: Serological tests to detect antibodies specific to Plasmodium vivax could be a valuable tool for epidemiological studies, for screening blood donors in areas where the malaria is not endemic and for diagnosis of infected individuals. Because P. vivax cannot be easily obtained in vitro, ELISA assays using total or semi-purified antigens are rarely used. Based on this limitation, we tested whether recombinant proteins representing the 19 kDa C-terminal region of the merozoite surface protein-1 of P. vivax (MSP1(19)) could be useful for serological detection of malaria infection.Methods: Three purified recombinant proteins produced in Escherichia coli (GST-MSP1(19), His(6)-MSP1(19) and His(6)-MSP1(19)-PADRE) and one in Pichia pastoris (yMSP1(19)-PADRE) were compared for their ability to bind to IgG antibodies of individuals with patent P. vivax infection. the method was tested with 200 serum samples collected from individuals living in the north of Brazil in areas endemic for malaria, 53 serum samples from individuals exposed to Plasmodium falciparum infection and 177 serum samples from individuals never exposed to malaria.Results: Overall, the sensitivity of the ELISA assessed with sera from naturally infected individuals was 95%. the proportion of serum samples that reacted with recombinant proteins GST-MSP1(19), His(6)-MSP1(19), His(6)-MSP1(19)-PADRE and yMSP1(19)-PADRE was 90%, 93.5%, 93.5% and 93.5%, respectively. the specificity values of the ELISA determined with sera from healthy individuals and from individuals with other infectious diseases were 98.3% (GST-MSP1(19)), 97.7% (His(6)-MSP1(19) and His(6)-MSP1(19)-PADRE) or 100% (yMSP1(19)-PADRE).Conclusions: Our study demonstrated that for the Brazilian population, an ELISA using a recombinant protein of the MSP1(19) can be used as the basis for the development of a valuable serological assay for the detection of P. vivax malaria.Univ São Paulo, Dept Anal Clin & Toxicol, Fac Ciencias Farmaceut, BR-05508900 São Paulo, BrazilFed Univ Para, Dept Patol, Ctr Ciencias Biol, BR-66075900 Belem, Para, BrazilMinist Salud, Inst Evandro Chagas, Secretaria Vigilancia Saude, BR-66090000 Belem, Para, BrazilHosp Israelita Albert Einstein, Dept Hemoterapia, BR-05651901 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, BrazilWeb of Scienc

Intrauterine undernutrition - renal and vascular origin of hypertension

A large number of clinical and experimental studies supports the hypothesis that intrauterine undernutrition is an important determinant of hypertension, coronary heart disease and non-insulin-dependent diabetes in the adult offspring. in this review, the renal and vascular repercussions of maternal undernutrition are emphasized, and the physiopatologic mechanisms discussed. the origin of hypertension is detailed based upon the findings of kidney functional parameters and endothelium function studies. A working model linking hypertension to intrauterine undernutrition is proposed. (C) 2003 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.Univ São Paulo, ICB 1, Dept Farmacol, Lab Hipertensao, BR-05508900 São Paulo, SP, BrazilUniversidade Federal de São Paulo, São Paulo, SP, BrazilUniversidade Federal de São Paulo, São Paulo, SP, BrazilWeb of Scienc

Splash!: a prospective birth cohort study of the impact of environmental, social and family-level influences on child oral health and obesity related risk factors and outcomes

Background: Dental caries (decay) is the most prevalent disease of childhood. It is often left untreated and can impact negatively on general health, and physical, developmental, social and learning outcomes. Similar to other health issues, the greatest burden of dental caries is seen in those of low socio-economic position. In addition, a number of diet-related risk factors for dental caries are shared risk factors for the development of childhood obesity. These include high and frequent consumption of refined carbohydrates (predominately sugars), and soft drinks and other sweetened beverages, and low intake of (fluoridated) water. The prevalence of childhood obesity is also at a concerning level in most countries and there is an opportunity to determine interventions for addressing both of these largely preventable conditions through sustainable and equitable solutions. This study aims to prospectively examine the impact of drink choices on child obesity risk and oral health status.Methods/Design: This is a two-stage study using a mixed methods research approach. The first stage involves qualitative interviews of a sub-sample of recruited parents to develop an understanding of the processes involved in drink choice, and inform the development of the Discrete Choice Experiment analysis and the measurement instruments to be used in the second stage. The second stage involves the establishment of a prospective birth cohort of 500 children from disadvantaged communities in rural and regional Victoria, Australia (with and without water fluoridation). This longitudinal design allows measurement of changes in the child&rsquo;s diet over time, exposure to fluoride sources including water, dental caries progression, and the risk of childhood obesity.Discussion: This research will provide a unique contribution to integrated health, education and social policy and program directions, by providing clearer policy relevant evidence on strategies to counter social and environmental factors which predispose infants and children to poor health, wellbeing and social outcomes; and evidence-based strategies to promote health and prevent disease through the adoption of healthier lifestyles and diet. Further, given the absence of evidence on the processes and effectiveness of contemporary policy implementation, such as community water fluoridation in rural and regional communities it&rsquo;s approach and findings will be extremelyinformative.<br /

Amoxicillin / Clavulanic Acid and Cefotaxime Resistance in Salmonella Minnesota and Salmonella Heidelberg from Broiler Chickens

This study investigated the resistance of various Salmonella strains to beta-lactam antibiotics. Salmonella Minnesota (36 strains) and Salmonella Heidelberg (24 strains) were isolated from broiler chickens and carcasses by the Disk Diffusion Test and resistance genes blaCTX-M-8, blaACC-1 and blaCMY-2 were detected by PCR. Of the 60 strains tested, 80% were resistant to at least one antibiotic. Specifically, 66.7% were resistant to amoxicillin/clavulanic acid and 75% were resistant to cefotaxime. Among the amoxicillin/clavulanic acid resistant strains, the blaCMY-2 gene was detected in 40%, blaACC-1 in 37.5% and blaCTX-M-8 in 7.5%. Among the cefotaxime resistant strains, we detected the genes blaCTX-M-8 in 13.3%, blaACC-1 in 33.3%, and blaCMY-2 in 31.1%. The presence of cefotaxime- and amoxicillin/clavulanic acid-resistant Salmonella in poultry, and the prevalence of extended spectrum betalactamases and AmpC-betalactamases in these strains are of huge concern to public health and economy

Serotyping and Genotyping of Salmonella Strains Isolated From Broilers, Chicken Carcasses Before and After Chilling, and Frozen Chicken Breasts Produced in The States of Mato Grosso do Sul and Santa Catarina, Brazil

ABSTRACT The present study investigated the effectiveness of a single Salmonella prevention and control program applied in two different processing plants, located in the states of Mato Grosso do Sul (plant A) and Santa Catarina (Plant B), belonging to the same company, and identified Salmonella strain subtypes isolated from broilers, carcasses before and after chilling, and frozen chicken breasts. The Salmonella prevention and control program was 90% effective in plant A and 100% in plant B, considering a level of 10% positive samples per frozen chicken breast batch acceptable. A total of 128 strains were serotyped, being 10 from drag swabs, 31 from cloacal swabs, 83 from carcasses, and 4 from frozen chicken breasts. After serotyping analysis, 30 strains isolated at different processing steps and drag swabs, and three Salmonella Minnesota strains isolated in 2012 in plant A, were genotyped by PFGE. In plant A, the most frequently strain isolated was Salmonella Minnesota (90.35%), followed by Salmonella Newport (8.77%), and in Plant B, Salmonella Senftenberg (80%). Salmonella Minnesota strains were differentiated by PFGE into 19 pulsotypes distributed in three clusters. The phenotypic identification by serotyping of four strains diverged from their PFGE genotypic results. Most Salmonella Minnesota strains genotyped in plant A and the strains isolated from environmental samples in 2012 in the same broiler processing plant belong to a single cluster, confirming the dominance and persistence of this clone over time

Antibody response of naturally infected individuals to recombinant Plasmodium vivax apical membrane antigen-1

In the present study, we evaluate the naturally acquired antibody response to the Plasmodium vivax apical membrane antigen 1 (PvAMA-1), a leading vaccine candidate against malaria. the gene encoding the PvAMA-1 ectodomain region (amino acids 43-487) was cloned by PCR using genomic DNA from a Brazilian individual with patent P. vivax infection. the predicted amino acid sequence displayed a high degree of identity (97.3%) with a previously published sequence from the P. viva-v Salvador strain. A recombinant protein representing the PvAMA-1 ectodomain was expressed in Escherichia coli and refolded. By ELISA, this recombinant protein reacted with 85 and 48.5% of the IgG or IgM antibodies, respectively, from Brazilian individuals with patent P. vivax malaria. IgG I was the predominant subclass of IgG. the frequency of response increased according to the number of malaria episodes, reaching 100% in individuals in their fourth malaria episode. the high degree of recognition of PvAMA-1 by human antibodies was confirmed using a second recombinant protein expressed in Pichia pastoris (PV66/AMA-1). the observation that recognition of the bacterial recombinant PvAMA-1 was only slightly lower than that of the highly immunogenic 19 kDa C-terminal domain of the P. vivax Merozoite Surface Protein-1 was also important. DNA sequencing of the PvAMA-1 variable domain from 20 Brazilian isolates confirmed the limited polymorphism of PvAMA-1 suggested by serological analysis. in conclusion, we provide evidence that PvAMA-1 is highly immunogenic during natural infection in humans and displays limited polymorphism in Brazil. Based on these observations, we conclude that PvAMA-1 merits further immunological studies as a vaccine candidate against P. vivax malaria. (C) 2004 Australian Society for Parasitology Inc. Published by Elsevier B.V. All rights reserved.Univ São Paulo, Dept Anal Clin & Toxicol, Fac Ciencias Farmaceut, BR-05508900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, BR-04023062 São Paulo, BrazilBiomed Primate Res Ctr, Dept Parasitol, NL-2280 GH Rijswijk, NetherlandsUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, BR-04023062 São Paulo, BrazilWeb of Scienc

Serotyping and Genotyping of Salmonella Strains Isolated From Broilers, Chicken Carcasses Before and After Chilling, and Frozen Chicken Breasts Produced in The States of Mato Grosso do Sul and Santa Catarina, Brazil

<div><p>ABSTRACT The present study investigated the effectiveness of a single Salmonella prevention and control program applied in two different processing plants, located in the states of Mato Grosso do Sul (plant A) and Santa Catarina (Plant B), belonging to the same company, and identified Salmonella strain subtypes isolated from broilers, carcasses before and after chilling, and frozen chicken breasts. The Salmonella prevention and control program was 90% effective in plant A and 100% in plant B, considering a level of 10% positive samples per frozen chicken breast batch acceptable. A total of 128 strains were serotyped, being 10 from drag swabs, 31 from cloacal swabs, 83 from carcasses, and 4 from frozen chicken breasts. After serotyping analysis, 30 strains isolated at different processing steps and drag swabs, and three Salmonella Minnesota strains isolated in 2012 in plant A, were genotyped by PFGE. In plant A, the most frequently strain isolated was Salmonella Minnesota (90.35%), followed by Salmonella Newport (8.77%), and in Plant B, Salmonella Senftenberg (80%). Salmonella Minnesota strains were differentiated by PFGE into 19 pulsotypes distributed in three clusters. The phenotypic identification by serotyping of four strains diverged from their PFGE genotypic results. Most Salmonella Minnesota strains genotyped in plant A and the strains isolated from environmental samples in 2012 in the same broiler processing plant belong to a single cluster, confirming the dominance and persistence of this clone over time.</p></div