Gestational malaria associated to Plasmodium vivax and Plasmodium falciparum placental mixed-infection followed by foetal loss: a case report from an unstable transmission area in Brazil

Gestational malaria is a multi-factorial syndrome leading to poor outcomes for both the mother and foetus. Although an unusual increasing in the number of hospitalizations caused by Plasmodium vivax has been reported in Brazil, mortality is rarely observed. This is a report of a gestational malaria case that occurred in the city of Manaus (Amazonas State, Brazil) and resulted in foetal loss. The patient presented placental mixed-infection by Plasmodium vivax and Plasmodium falciparum after diagnosis by nested-PCR, however microscopic analysis failed to detect P. falciparum in the peripheral blood. Furthermore, as the patient did not receive proper treatment for P. falciparum and hospitalization occurred soon after drug treatment, it seems that P. falciparum pathology was modulated by the concurrent presence of P. vivax. Collectively, this case confirms the tropism towards the placenta by both of these species of parasites, reinforces the notion that co-existence of distinct malaria parasites interferes on diseases' outcomes, and opens discussions regarding diagnostic methods, malaria treatment during pregnancy and prenatal care for women living in unstable transmission areas of malaria, such as the Brazilian Amazon

Proteomic analysis of Chromobacterium violaceum and its adaptability to stress

Chromobacterium violaceum (C. violaceum) occurs abundantly in a variety of ecosystems, including ecosystems that place the bacterium under stress. This study assessed the adaptability of C. violaceum by submitting it to nutritional and pH stresses and then analyzing protein expression using bi-dimensional electrophoresis (2-DE) and Maldi mass spectrometry. Chromobacterium violaceum grew best in pH neutral, nutrient-rich medium (reference conditions); however, the total protein mass recovered from stressed bacteria cultures was always higher than the total protein mass recovered from our reference culture. The diversity of proteins expressed (repressed by the number of identifiable 2-DE spots) was seen to be highest in the reference cultures, suggesting that stress reduces the overall range of proteins expressed by C. violaceum. Database comparisons allowed 43 of the 55 spots subjected to Maldi mass spectrometry to be characterized as containing a single identifiable protein. Stress-related expression changes were noted for C. violaceum proteins related to the previously characterized bacterial proteins: DnaK, GroEL-2, Rhs, EF-Tu, EF-P; MCP, homogentisate 1,2-dioxygenase, Arginine deiminase and the ATP synthase β-subunit protein as well as for the ribosomal protein subunits L1, L3, L5 and L6. The ability of C. violaceum to adapt its cellular mechanics to sub-optimal growth and protein production conditions was well illustrated by its regulation of ribosomal protein subunits. With the exception of the ribosomal subunit L3, which plays a role in protein folding and maybe therefore be more useful in stressful conditions, all the other ribosomal subunit proteins were seen to have reduced expression in stressed cultures. Curiously, C. violeaceum cultures were also observed to lose their violet color under stress, which suggests that the violacein pigment biosynthetic pathway is affected by stress. Analysis of the proteomic signatures of stressed C. violaceum indicates that nutrient-starvation and pH stress can cause changes in the expression of the C. violaceum receptors, transporters, and proteins involved with biosynthetic pathways, molecule recycling, energy production. Our findings complement the recent publication of the C. violeaceum genome sequence and could help with the future commercial exploitation of C. violeaceum

Development of an antibody against EtpA from enterotoxigenic Escherichia coli and evaluation of its use for bacterial isolation using magnetic beads

Abstract The enterotoxigenic Escherichia coli (ETEC) strain is one of the most frequent causative agents of childhood diarrhea and travelers’ diarrhea in low-and middle-income countries. Among the virulence factors secreted by ETEC, the exoprotein EtpA has been described as an important. In the present study, a new detection tool for enterotoxigenic E. coli bacteria using the EtpA protein was developed. Initially, antigenic sequences of the EtpA protein were selected via in silico prediction. A chimeric recombinant protein, corresponding to the selected regions, was expressed in an E. coli host, purified and used for the immunization of mice. The specific recognition of anti-EtpA IgG antibodies generated was evaluated using flow cytometry. The tests demonstrated that the antibodiesdeveloped were able to recognize the native EtpA protein. By coupling these antibodies to magnetic beads for the capture and detection of ETEC isolates, cytometric analyses showed an increase in sensitivity, specificity and the effectiveness of the method of separation and detection of these pathogens. This is the first report of the use of this methodology for ETEC separation. Future trials may indicate their potential use for isolating these and other pathogens in clinical samples, thus accelerating the diagnosis and treatment of diseases

Adherence and virulence genes of Escherichia colifrom children diarrhoea in the Brazilian Amazon

The bacterial pathogen most commonly associated with endemic forms of childhood diarrhoea is Escherichia coli. Studies of epidemiological characteristics of HEp-2 cell-adherent E. coli in diarrhoeal disease are required, particularly in developing countries. The aim of this study was evaluate the presence and significance of adherent Escherichia coli from diarrhoeal disease in children. The prevalence of LA, AA, and DA adherence patterns were determined in HEp-2 cells, the presence of virulence genes and the presence of the O serogroups in samples obtained from 470 children with acute diarrhoea and 407 controls in Porto Velho, Rondônia, Brazil. E. coli isolates were identified by PCR specific for groups of adherent E. coli. Out of 1,156 isolates obtained, 128 (11.0%) were positive for eae genes corresponding to EPEC, however only 38 (29.6%) of these amplified bfpAgene. EAEC were isolated from 164 (14.1%) samples; of those 41(25%), 32 (19%) and 16 (9.7%) amplified eagg, aggA or aafA genes, respectively and aggA was significantly associated with diarrhoea (P = 0.00006). DAEC identified by their adhesion pattern and there were few isolates. In conclusion, EAEC was the main cause of diarrhoea in children, especially when the aggA gene was present, followed by EPEC and with a negligible presence of DAEC

Immunophenotyping in Saliva as an Alternative Approach for Evaluation of Immunopathogenesis in Chronic Periodontitis

Made available in DSpace on 2015-05-27T13:39:47Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) raquel_ferrazetal_IOC_2014.pdf: 1083647 bytes, checksum: 0cfdc88dfdfe0baee8dc35638525e5b8 (MD5) Previous issue date: 2014Universidade do Estado do Amazonas (UEA). Escola de Ciências da Saúde. Faculdade de Odontologia. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Plataforma de Citometria de Fluxo – Purificação Celular. Laboratório de Imunoparasitologia. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunoparasitologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Leônidas e Maria Deane. Departamento de Biodiversidade em Saúde. Manaus, Am, Brasil.Universidade Federal do Amazonas (UFA). Instituto de Ciências Biológicas. Departamento de Parasitologia. Laboratório de Imunologia. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Plataforma de Citometria de Fluxo – Purificação Celular. Laboratório de Imunoparasitologia. Rio de Janeiro, RJ, Brasil.Universidade Federal do Amazonas (UFA). Instituto de Ciências Biológicas. Departamento de Parasitologia. Laboratório de Imunologia. Manaus, AM, Brasil.Background: To date, flow cytometric immunophenotyping has not been used to investigate immune patterns in saliva samples from individuals with inflammatory processes in the oral cavity, such as chronic periodontitis (CP). Saliva analysis could be a non-invasive method for evaluating oral health. The objective of this study is to determine the phenotype of leukocytes and total immunoglobulin A (IgA), IgG, and IgM titers in the saliva of individuals with CP. Methods: Saliva samples were obtained from patients with CP (n = 12) and from a control group (n = 27) without oral diseases. Flow cytometry was performed to determine the frequency of T cells (CD4+ and CD8+), B cells, and natural killer (NK) cells as well as the total leukocyte population. Immunoglobulin titers were determined by dot enzyme-linked immunosorbent assay. Results: Cell immunophenotyping revealed that patients with CP had a higher frequency of total leukocytes (47.94% ± 5.1%; P < 0.001), B cells (43.93% ± 6.2%; P = 0.006), NK cells (0.16% ± 0.04%; P = 0.03), and CD4+ T cells (38.99% ± 4.4%; P = 0.002) than individuals without oral pathologies (24.75% ± 2.2%, 20.60% ± 2.7%, 0.09% ± 0.03%, and 16.82% ± 3.5%, respectively). No significant differences in salivary total IgA, IgG, and IgM titers were found between the two cohorts studied. Nevertheless, higher total IgG levels were observed in patients with CP, which could indicate a possible correlation between clinical attachment level and salivary IgG (P = 0.07; r2 = 0.08). Conclusion: These results show that cell phenotyping by flow cytometry could be an effective tool for determining leukocyte profiles in saliva samples from patients with CP and healthy individuals