Leptospirosis disproportionately affects residents of urban slums. To understand the knowledge, attitudes, and practices regarding leptospirosis, we conducted a cross-sectional study among residents of an urban slum community in Salvador, Brazil. Of the 257 residents who were interviewed, 225 (90%) were aware of leptospirosis and more than two-thirds of respondents correctly identified the modes of disease transmission and ways to reduce exposure. However, study participants who performed risk activities such as cleaning open sewers had limited access to protective clothing such as boots (33%) or gloves (35%). Almost all respondents performed at least one activity to prevent household rat infestation, which often included use of an illegal poison. Our findings support the need for interventions targeted at the individual and household levels to reduce risk of leptospirosis until large-scale structural interventions are available to residents of urban slum communities.
Fetal skin has the intrinsic capacity for wound healing, which is not correlated with the intrauterine environment. This intrinsic ability requires biochemical signals, which start at the cellular level and lead to secretion of transforming factors and expression of receptors, and specific markers that promote wound healing without scar formation. The mechanisms and molecular pathways of wound healing still need to be elucidated to achieve a complete understanding of this remodeling system. The aim of this paper is to discuss the main biomarkers involved in fetal skin wound healing as well as their respective mechanisms of action.
Hematological analysis has limited applications for disease diagnosis in Leishmania infantum–infected dogs, but it can be very important in evaluating the clinical forms of the disease and in understanding the evolution of canine visceral leishmaniasis (CVL) pathogenesis. Recently, we demonstrated that alterations in leucopoiesis and erythropoiesis are related to clinical status and bone marrow parasite density in dogs naturally infected by L. infantum. To further characterize these alterations, we evaluated the association between the hematological parameters in bone marrow and peripheral blood alterations in groups of L. infantum–infected dogs: asymptomatic I (AD-I: serum negative/PCR+), asymptomatic II (AD-II: serum positive), oligosymptomatic (OD), and symptomatic (SD). Results were compared with those from noninfected dogs (NID). The SD group was found to present a decrease in erythropoietic lineage with concomitant reductions in erythrocytes, hemoglobin, and hematocrit parameters, resulting in anemia. The SD group also had increased neutrophils and precursors and decreased band eosinophils and eosinophils, leading to peripheral blood leucopenia. In the AD-II group, lymphocytosis occurred in both the peripheral blood and the bone marrow compartments. The SD group exhibited lymphocytosis in the bone marrow, with lymphopenia in the peripheral blood. In contrast, the AD-I group, showed no significant changes suggestive of CVL, presenting normal counts in bone marrow and peripheral blood. Our results showed for the first time that important changes in hematopoiesis and hematological parameters occur during ongoing CVL in naturally infected dogs, mainly in symptomatic disease. Taken together, our results based on myelogram and hemogram parameters enable better understanding of the pathogenesis of the anemia, lymphocytosis, and lymphopenia, as well as the leucopenia (eosinopenia and monocytopenia), that contribute to CVL prognosis.
Brazil remains the country in the Americas with the highest prevalence of schistosomiasis. A combination of control efforts and development, however, has sharply reduced its intensity and distribution. The acquisition of specific schistosome populations may be dependent on host characteristics such as sex, age, geography, work, habits and culture. How these and other host characteristics align with parasite subpopulations may guide approaches to improve control.
A cohort of more than 90% of the residents in two rural communities in Brazil participated in an epidemiologic survey of demographic, socio-economic and behavioral characteristics. The variables sex, age, intensity of infection, socio-economic index, % lifetime spent on site, previous infection, and trips outside the district were used to group parasites infecting individuals. Schistosoma mansoni infection status was determined by examination of stools submitted on 3 different days. The aggregate of eggs collected from the whole stool was used to determine degree of population differentiation from allele frequencies for 15 microsatellites.
Infection prevalence was 41% for these communities, and the epidemiologic characteristics were similar to many of the endemic areas of Brazil and the world. Parasite population structuring was observed between the two communities (Jost's D 0.046, CI95% 0.042–0.051), although separated by only 8 km and connected by a highway. No structuring was observed when infected individuals were stratified by host's biologic, demographic or epidemiologic characteristics. Those most heavily infected best reflected the communities' overall parasite diversity. The lack of differentiation within villages suggests that individuals are likely to get infected at the same sites or that the same parasite multilocus genotypes can be found at most sites. The geographic structuring between villages and the lack of structuring by age of the host further supports the impression of a population little affected by migration or drift.
Schistosomiasis is one of the world's most important parasitic infections. Its elimination has proved difficult even in countries such as Brazil where access to treatment is readily available. Infection is the result of human contact with surface water where there are infected snails, so that human biology and habits may bring different individuals in contact with different groups of parasites. Identification of schistosome subpopulations may assist understanding transmission patterns and guide control efforts. We compared microsatellite allele frequencies from all of the infections in 2 small villages and determined that the movement of parasites between them was limited. Individual infections were distinct composites of parasites, but if infected humans were grouped by demographic and epidemiologic characteristics, there was no evidence that specific parasite subpopulations were being selected in these types of hosts. Infections were also not differentiated when stratified by host's age indicating that the populations were stable over time. Since the infection cycle requires human fecal contamination of water, local human behavior can to some degree be inferred from the patterns of schistosome subpopulation distribution.
Rapid urbanization in Brazil has meant that many persons from rural areas where Schistosoma mansoni is endemic have migrated to cities. Discovery of a focus of active transmission in the city of Salvador prompted a citywide survey for active and potential transmission sites. Cercariae shed from infected snails collected from four locations were used to determine how these samples were related and if they were representative of the parasite population infecting humans. Each cercarial collection was greatly differentiated from the others, and diversity was significantly lower when compared with eggs from natural human infections in one site. Egg samples collected 7 years apart in one neighborhood showed little differentiation (Jost's D = 0.01–0.03). Given the clonal nature of parasite reproduction in the snail host and the short-term acquisition of parasites, cercariae from collections at one time point are unlikely to be representative of the diversity in the human population.
Bullous pemphigoid is an autoimmune subepidermal blistering dermatosis that is
uncommon in childhood. We report a case of a female infant, 3 months old, which
presented clinical and laboratory data for the confirmatory diagnosis of bullous
pemphigoid. The authors used immunohistochemical staining for collagen type IV that
allowed the differentiation of bullous pemphigoid from other subepidermal bullous
diseases. Opportunely we review the clinical, immunological, therapeutic and
prognostic features of this pathology in children.
Child; Collagen type IV; Pemphigoid, bullous; Skin diseases, vesiculobullous
The role of the immune response in influencing leptospirosis clinical outcomes is not yet well understood. We hypothesized that acute-phase serum cytokine responses may play a role in disease progression, risk for death, and severe pulmonary hemorrhage syndrome (SPHS).
We performed a case-control study design to compare cytokine profiles in patients with mild and severe forms of leptospirosis. Among patients hospitalized with severe disease, we compared those with fatal and nonfatal outcomes. During active outpatient and hospital-based surveillance we prospectively enrolled 172 patients, 23 with mild disease (outpatient) and 149 with severe leptospirosis (hospitalized). Circulating concentrations of pro- and anti-inflammatory cytokines at the time of patient presentation were measured using a multiplex bead array assay. Concentrations of IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-17A, and TNF-α were significantly higher (P<0.05) in severe disease compared to mild disease. Among severe patients, levels of IL-6 (P<0.001), IL-8 (P = 0.0049) and IL-10 (P<0.001), were higher in fatal compared to non-fatal cases. High levels of IL-6 and IL-10 were independently associated (P<0.05) with case fatality after adjustment for age and days of symptoms. IL-6 levels were higher (P = 0.0519) among fatal cases who developed SPHS than among who did not.
This study shows that severe cases of leptospirosis are differentiated from mild disease by a “cytokine storm” process, and that IL-6 and IL-10 may play an immunopathogenic role in the development of life-threatening outcomes in human leptospirosis.
Leptospirosis is a tropical bacterial disease that is transmitted to humans from infected animals. Leptospirosis symptoms can range from mild fever to fatal disease forms, such as massive bleeding into the lungs, called Severe Pulmonary Hemorrhage Syndrome (SPHS). It is not known what determines the severity of leptospirosis, but we hypothesized that it may be influenced by differences in the type and concentration of signaling proteins called cytokines that are produced by the immune system in response to infection. We collected blood from patients with mild and severe leptospirosis, and compared the concentration of eight different cytokines circulating in the blood. We found that patients with severe leptospirosis had higher levels of most cytokines. Among patients who had severe forms, higher levels of specific cytokines called IL-6 and IL-8 were predictive of death even after statistical adjustment for age and number of days of symptoms prior to hospitalization. IL-6 was higher in patients who died from SPHS compared to those who died of other leptospirosis complications. This knowledge suggests that severe forms of leptospirosis may be due to a specific kind of immune response, which may lead to targeted therapies to reduce the impact of this disease.
Antibody-mediated rejection (AMR) is highly detrimental to the prolonged survival of transplanted kidneys. C4d has been regarded as a footprint of AMR tissue damage, and the introduction of C4d staining in daily clinical practice aroused an ever-increasing interest in the role of antibody-mediated mechanisms in allograft rejection. Despite the general acceptance of the usefulness of C4d in the identification of acute AMR, the data for C4d staining in chronic AMR is variable. The presence of C4d in the majority of the biopsies with features of chronic antibody-mediated rejection is reported, but this rejection without C4d staining is observed as well, suggesting that C4d is specific but not sensitive. Further studies on AMR with positive C4d staining in biopsy specimens are really important, as well as the study of novel routine markers that may participate in the pathogenesis of this process.
The increasing in the number of kidney transplant recipients has favored, more frequently than before, the emergence of dermatoses and warranted their study through subsequent publications.
to evaluate the frequency of dermatoses in kidney transplant recipients.
kidney transplant recipients with suspected dermatoses between March 1st 2009 and June 30th 2010.
53 patients (28 males and 25 females), aged between 22 and 69 (mean age = 45 years) were evaluated. Most of them came from the cities of Ceilândia, Samambaia and São Sebastião/DF, and had already been transplanted for 5 to 10 years before (37.7%); 62.3% were recipients of living donors and 83% were prednisone-treated. The most prevalent dermatoses were of fungal (45.3%) and viral (39.6%) etiologies. Among the non-melanoma malignant neoplasms, the basal cell carcinoma prevailed (six cases), in spite of the low incidence. Concerning fungal dermatoses, 12 cases of onychomycosis, five of pityriasis versicolor and four of pityrosporum folliculitis were reported. For diagnosis, in most cases (64.2%), laboratory examinations (mycological and histopathological) were performed.
cutaneous manifestations in kidney transplant recipients are generally secondary to immunosuppression. The infectious dermatoses, especially those of fungal origin, are frequently found in kidney transplant recipients and their occurrence increases progressively according to the time elapsed from the transplantation, which makes follow-up important.
Immunosuppression; Kidney transplantation; Onychomycosis; Prednisone
Several forebrain and brainstem neurochemical circuitries interact with
peripheral neural and humoral signals to collaboratively maintain both the
volume and osmolality of extracellular fluids. Although much progress has been
made over the past decades in the understanding of complex mechanisms underlying
neuroendocrine control of hydromineral homeostasis, several issues still remain
to be clarified. The use of techniques such as molecular biology, neuronal
tracing, electrophysiology, immunohistochemistry, and microinfusions has
significantly improved our ability to identify neuronal phenotypes and their
signals, including those related to neuron-glia interactions. Accordingly,
neurons have been shown to produce and release a large number of chemical
mediators (neurotransmitters, neurohormones and neuromodulators) into the
interstitial space, which include not only classic neurotransmitters, such as
acetylcholine, amines (noradrenaline, serotonin) and amino acids (glutamate,
GABA), but also gaseous (nitric oxide, carbon monoxide and hydrogen sulfide) and
lipid-derived (endocannabinoids) mediators. This efferent response, initiated
within the neuronal environment, recruits several peripheral effectors, such as
hormones (glucocorticoids, angiotensin II, estrogen), which in turn modulate
central nervous system responsiveness to systemic challenges. Therefore, in this
review, we shall evaluate in an integrated manner the physiological control of
body fluid homeostasis from the molecular aspects to the systemic and integrated
Hypothalamus; Gaseous neuromodulators; Neuropeptides; Endocannabinoids; Glial cells; Neurotransmitters
Although cerebrospinal fluid (CSF) culture is the diagnostic reference standard for bacterial meningitis, its sensitivity is limited, particularly when antibiotics were previously administered. CSF Gram staining and real-time PCR are theoretically less affected by antibiotics; however, it is difficult to evaluate these tests with an imperfect reference standard.
Methods and findings
CSF from patients with suspected meningitis from Salvador, Brazil were tested with culture, Gram stain, and real-time PCR using S. pneumoniae, N. meningitidis, and H. influenzae specific primers and probes. An antibiotic detection disk bioassay was used to test for the presence of antibiotic activity in CSF. The diagnostic accuracy of tests were evaluated using multiple methods, including direct evaluation of Gram stain and real-time PCR against CSF culture, evaluation of real-time PCR against a composite reference standard, and latent class analysis modeling to evaluate all three tests simultaneously.
Among 451 CSF specimens, 80 (17.7%) had culture isolation of one of the three pathogens (40 S. pneumoniae, 36 N. meningitidis, and 4 H. influenzae), and 113 (25.1%) were real-time PCR positive (51 S. pneumoniae, 57 N. meningitidis, and 5 H. influenzae). Compared to culture, real-time PCR sensitivity and specificity were 95.0% and 90.0%, respectively. In a latent class analysis model, the sensitivity and specificity estimates were: culture, 81.3% and 99.7%; Gram stain, 98.2% and 98.7%; and real-time PCR, 95.7% and 94.3%, respectively. Gram stain and real-time PCR sensitivity did not change significantly when there was antibiotic activity in the CSF.
Real-time PCR and Gram stain were highly accurate in diagnosing meningitis caused by S. pneumoniae, N. meningitidis, and H. influenzae, though there were few cases of H. influenzae. Furthermore, real-time PCR and Gram staining were less affected by antibiotic presence and might be useful when antibiotics were previously administered. Gram staining, which is inexpensive and commonly available, should be encouraged in all clinical settings.
Bacterial meningitis; Diagnostic test evaluation; Real-time PCR; Streptococcus pneumoniae; Neisseria meningitidis; Haemophilus influenzae
Objective. To analyze the cytokines of the innate immune pulmonary response and the capacity for local response to melatonin according to the perinatal stress. Methods. 49 cases of pediatric autopsies were evaluated, divided according to cause of death, perinatal stress, gestational age, and birth weight. The percentages of IL-6, C-reactive protein (CRP), IL-1β, TNF-α, and melatonin receptor were evaluated by immunohistochemistry. Results. The IL-6 expression was higher in the children showing chronic stress, anoxia, and infection. The IL-6 expression showed a progressive increase according to the relation between weight and GA. There was no significant difference in the expression of IL-1β and TNF-α. The CRP expression was higher in the cases showing chronic stress and premature cases. The expression of melatonin receptors was significantly higher in the cases showing chronic stress, being more evident in the cases showing infection. Conclusion. The cause of death and the type of stress influence the expression in situ of melatonin and cytokines of the innate immune pulmonary response. The evaluation of IL-6 and CRP may contribute to the understanding of the evolution of neonates with chronic stress. The greater sensitivity of the lung to melatonin in these cases may indicate an attempt at controlling the immunological response, in an attempt to diminish the harmful effects of stress.
The regular practice of physical exercise has been associated with beneficial effects on various pulmonary conditions. We investigated the mechanisms involved in the protective effect of exercise in a model of lipopolysaccharide (LPS)-induced acute lung injury (ALI).
Mice were divided into four groups: Control (CTR), Exercise (Exe), LPS, and Exercise + LPS (Exe + LPS). Exercised mice were trained using low intensity daily exercise for five weeks. LPS and Exe + LPS mice received 200 µg of LPS intratracheally 48 hours after the last physical test. We measured exhaled nitric oxide (eNO); respiratory mechanics; neutrophil density in lung tissue; protein leakage; bronchoalveolar lavage fluid (BALF) cell counts; cytokine levels in BALF, plasma and lung tissue; antioxidant activity in lung tissue; and tissue expression of glucocorticoid receptors (Gre).
LPS instillation resulted in increased eNO, neutrophils in BALF and tissue, pulmonary resistance and elastance, protein leakage, TNF-alpha in lung tissue, plasma levels of IL-6 and IL-10, and IL-1beta, IL-6 and KC levels in BALF compared to CTR (P ≤0.02). Aerobic exercise resulted in decreases in eNO levels, neutrophil density and TNF-alpha expression in lung tissue, pulmonary resistance and elastance, and increased the levels of IL-6, IL-10, superoxide dismutase (SOD-2) and Gre in lung tissue and IL-1beta in BALF compared to the LPS group (P ≤0.04).
Aerobic exercise plays important roles in protecting the lungs from the inflammatory effects of LPS-induced ALI. The effects of exercise are mainly mediated by the expression of anti-inflammatory cytokines and antioxidants, suggesting that exercise can modulate the inflammatory-anti-inflammatory and the oxidative-antioxidative balance in the early phase of ALI.
Paracoccidioides brasiliensis is the etiologic agent of paracoccidioidomycosis (PCM), one of the most prevalent mycosis in Latin America. P. brasiliensis cell wall components interact with host cells and influence the pathogenesis of PCM. Cell wall components, such as glycosylphosphatidylinositol (GPI)-proteins play a critical role in cell adhesion and host tissue invasion. Although the importance of GPI-proteins in the pathogenesis of other medically important fungi is recognized, little is known about their function in P. brasiliensis cells and PCM pathogenesis. We cloned the PbPga1 gene that codifies for a predicted GPI-anchored glycoprotein from the dimorphic pathogenic fungus P. brasiliensis. PbPga1 is conserved in Eurotiomycetes fungi and encodes for a protein with potential glycosylation sites in a serine/threonine-rich region, a signal peptide and a putative glycosylphosphatidylinositol attachment signal sequence. Specific chicken anti-rPbPga1 antibody localized PbPga1 on the yeast cell surface at the septum between the mother cell and the bud with stronger staining of the bud. The exposure of murine peritoneal macrophages to rPbPga1 induces TNF-α release and nitric oxide (NO) production by macrophages. Furthermore, the presence of O-glycosylation sites was demonstrated by β-elimination under ammonium hydroxide treatment of rPbPga1. Finally, sera from PCM patients recognized rPbPga1 by Western blotting indicating the presence of specific antibodies against rPbPga1. In conclusion, our findings suggest that the PbPga1gene codifies for a cell surface glycoprotein, probably attached to a GPI-anchor, which may play a role in P. brasiliensis cell wall morphogenesis and infection. The induction of inflammatory mediators released by rPbPga1 and the reactivity of PCM patient sera toward rPbPga1 imply that the protein favors the innate mechanisms of defense and induces humoral immunity during P. brasiliensis infection.
The allergic test of mallein is one of the most frequently used tests, together with the Complement Fixation Test (CFT), for the diagnosis of glanders in endemic areas. Mallein, a purified protein derivative (PPD), is produced similarly to PPD tuberculin and the end product is a primarily proteic antigen, which is only poorly purified. The immuno-allergic activity of mallein is believed to be due to a high molecular weight group of proteins present in the antigen. To improve the quality of the antigen, in terms of sensitivity and specificity, a new method of mallein production was developed, in which purification was accomplished by ultrafiltration in a Tangential Flow Filtration system (TFF).
The TFF methodology efficiently separated the high and low molecular weight protein groups of mallein. The five TFF-purified malleins, produced from Burkholderia mallei strains isolated from clinical cases of glanders in Brazil, proved to be more potent than standard mallein in the induction of an allergic reaction in sensitized animals. Regarding specificity, two of the purified malleins were equivalent to the standard and three were less specific.
Some of the TFF-purified malleins showed considerable potential to be used as an auxiliary test in the diagnosis of glanders.
Equine; Glanders; Mallein; Antigen; Diagnosis; Purification
Praziquantel has been used to treat schistosome infections since 1979 and currently is the only chemotherapeutic agent in production for this purpose, raising concerns about the potential for the emergence of drug resistance. In practice, 10–20% of infected patients will continue to excrete eggs after treatment. It is not understood to what degree this represents selection of a resistant population or incomplete elimination due to the presence of immature worms at the time of treatment. We used a population genetics approach to test whether or not persistent Schistosoma mansoni parasites were drawn from the same population as susceptible parasites. In this study, stool samples were collected from 96% of individuals in two small Brazilian communities (populations 482 and 367) and examined for S. mansoni eggs. The combined prevalence of S. mansoni infections in the villages was 41%. Total egg DNA was extracted from each sample and was genotyped at 15 microsatellite markers. Day-to-day variation of the infrapopulation from an individual human host was low (median differentiation using Jost’s D = 0.010), so that a single stool was representative of the genotypes present in stool eggs, at least in the short term. Average pairwise analysis of D among all pre-treatment infrapopulations suggested moderate differentiation (mean D = 0.082 and 0.122 for the two villages), whereas the pre-treatment component population differentiation between the two communities was 0.047. The differentiation of the component population remaining after treatment from the fully susceptible component population was low (mean D = 0.007 and 0.020 for the two villages), suggesting that the persistent parasites were not selected by praziquantel treatment. We will continue to follow these communities for evidence of selection or changes in population structure.
Praziquantel; Resistance; Microsatellite; Population genetics; Sampling; Genetic differentiation; Selection
Prognosis of prostate cancer (PCa) is based mainly in histological aspects together with PSA serum levels that not always reflect the real aggressive potential of the neoplasia. The micro RNA (miRNA) mir-21 has been shown to regulate invasiveness in cancer through translational repression of the Metaloproteinase (MMP) inhibitor RECK. Our aim is to investigate the levels of expression of RECK and miR-21 in PCa comparing with classical prognostic factors and disease outcome and also test if RECK is a target of miR-21 in in vitro study using PCa cell line.
Materials and methods
To determine if RECK is a target of miR-21 in prostate cancer we performed an in vitro assay with PCa cell line DU-145 transfected with pre-miR-21 and anti-miR-21. To determine miR-21 and RECK expression levels in PCa samples we performed quantitative real-time polymerase chain reaction (qRT-PCR).
The in vitro assays showed a decrease in expression levels of RECK after transfection with pre-miR-21, and an increase of MMP9 that is regulated by RECK compared to PCa cells treated with anti-miR-21. We defined three profiles to compare the prognostic factors. The first was characterized by miR-21 and RECK underexpression (N = 25) the second was characterized by miR-21 overexpression and RECK underexpression (N = 12), and the third was characterized by miR-21 underexpression and RECK overexpression (N = 16). From men who presented the second profile (miR-21 overexpression and RECK underexpression) 91.7% were staged pT3. For the other two groups 48.0%, and 46.7% of patients were staged pT3 (p = 0.025).
Our results demonstrate RECK as a target of miR-21. We believe that miR-21 may be important in PCa progression through its regulation of RECK, a known regulator of tumor cell invasion.
Prostate cancer; Prognosis; RECK; Micro RNA; Metaloproteinases
This study describes the serotype distribution and antibiotic resistance patterns among 397 S. pneumoniae meningitis case isolates recovered in Salvador, Brazil, during the period of 2000-2007, before introduction of the 10-valent pneumococcal conjugate vaccine.
The active hospital-based surveillance showed a decline in the annual incidence rates of pneumococcal meningitis during the period of study, from 1.12 cases to 0.83 cases/100,000 persons for all age groups (P <0.001), with an overall case-fatality rate of 28.6 % (113 of 395) for all patients and 41.9% (57 of 136) for those <5 years of age. Serotypes 14 (n= 55; 13.9%), 3 (n= 32; 8.1 %), 23F (n=32; 8.1 %), 19F (n=31; 7.8%), 6B (n=30; 7.6%), 18C (n=28; 7.1 %), and 6A (n=20; 5%) were the most prevalent serotypes. In patients < 5 years the estimated projected coverage of 7-, 10- and 13-valent conjugate vaccines was 74.3%, 75.7% and 83.1%, respectively. Antimicrobial susceptibility testing revealed that 22.1% (n=88) of isolates were non-susceptible to penicillin, 56% were non-susceptible to trimethoprim/sulfamethoxazole, and 29.6% were non-susceptible to tetracycline. Nonsusceptibility to penicillin and cefotaxime was detected solely among serotype 14 isolates (n=4; 1%). This study provides an important baseline to assess the impact of conjugate vaccine implantation on the epidemiology of meningitis due to Streptococcus pneumoniae in Salvador, Brazil.
Streptococcus pneumoniae; Vaccine; Antimicrobial resistance; Meningitis; Children
Prior to the availability of generic third-generation cephalosporins, penicillins were widely used for treatment of pneumococcal meningitis in developing countries despite concerns about rising levels of penicillin resistance among pneumococcal isolates. We examined the impact of penicillin resistance on outcomes of pneumococcal meningitis over a ten year period in an infectious diseases hospital in Brazil.
Clinical presentation, antimicrobial therapy and outcomes were reviewed for 548 patients with culture-confirmed pneumococcal meningitis from December, 1995, to November, 2005. Pneumococcal isolates from meningitis patients were defined as penicillin-resistant if Minimum Inhibitory Concentrations for penicillin were greater than 0.06 μg/ml. Proportional hazards regression was used to identify risk factors for fatal outcomes.
During the ten-year period, ceftriaxone replaced ampicillin as first-line therapy for suspected bacterial meningitis. In hospital case-fatality for pneumococcal meningitis was 37%. Of 548 pneumococcal isolates from meningitis cases, 92 (17%) were resistant to penicillin. After controlling for age and severity of disease at admission, penicillin resistance was associated with higher case-fatality (Hazard Ratio [HR], 1.62; 95% Confidence Interval [CI], 1.08-2.43). Penicillin-resistance remained associated with higher case-fatality when initial therapy included ceftriaxone (HR, 1.68; 95% CI 1.02-2.76).
Findings support the use of third generation cephalosporin antibiotics for treatment of suspected pneumococcal meningitis even at low prevalence of pneumococcal resistance to penicillins.
Following introduction of Haemophilus influenzae type b (Hib) conjugate vaccines, meningitis caused by serotypes other than Hib has gained importance. We conducted active hospital-based surveillance for meningitis over an 11-year period in Salvador, Brazil. H. influenzae isolates were serotyped and analyzed by PCR, pulsed-field gel electrophoresis and DNA sequencing to identify strains with a specific deletion (IS1016) in the bexA gene (IS1016-bexA). We identified 43 meningitis cases caused by non-type b H. influenzae: 28 (65%) were caused by type a (Hia), 9 (21%) by non-capsulated strains and 3 (7%) each by types e and f. Hia isolates clustered in two clonal groups; clonal group A strains (n=9) had the IS1016-bexA deletion. Among children <5 years, meningitis caused by Hia from clonal group A had higher case-fatality than clonal group B. Despite small numbers, these results indicate that the presence of IS1016-bexA deletion is associated with enhanced virulence in non-type b H. influenzae.
Haemophilus influenzae; non-type b H. influenzae; meningitis; Hib conjugate vaccine; virulence; IS1016-bexA deletion; molecular epidemiology
To identify genes associated with the clinical presentation of dengue, 50 cases of probable or possible dengue hemorrhagic fever (DHF), 236 dengue fever (DF), and 236 asymptomatic infections were genotyped for 593 single-nucleotide polymorphisms (SNPs) in 56 genes across the type 1 interferon (IFN) response pathway as well as other important candidate genes. By single locus analysis comparing DHF with DF, 11 of the 51 markers with P<0.05 were in the JAK1 gene. Five markers were significantly associated by false discovery rate criteria (q<0.20 when P<6 × 10−4). The JAK1 SNPs showed differential distribution by ethnicity and ancestry consistent with epidemiologic observations in the Americas. The association remained significant after controlling for ancestry and income. No association was observed with markers in the gene encoding CD209 (DC-SIGN). An association between DHF and JAK1 polymorphisms is in agreement with expression profiles showing generalized decreased type 1 IFN-stimulated gene expression in these patients.
flavivirus; population structure; interferon; genetic association; Brazil
The endoplasmic reticulum (ER) is a major signaling organelle, which integrates a variety of responses against physiological stresses. In plants, one such stress-integrating response is the N-rich protein (NRP)-mediated cell death signaling pathway, which is synergistically activated by combined ER stress and osmotic stress signals. Despite the potential of this integrated signaling to protect plant cells against different stress conditions, mechanistic knowledge of the pathway is lacking, and downstream components have yet to be identified.
In the present investigation, we discovered an NAC domain-containing protein from soybean, GmNAC6 (Glycine max NAC6), to be a downstream component of the integrated pathway. Similar to NRP-A and NRP-B, GmNAC6 is induced by ER stress and osmotic stress individually, but requires both signals for full activation. Transient expression of GmNAC6 promoted cell death and hypersensitive-like responses in planta. GmNAC6 and NRPs also share overlapping responses to biotic signals, but the induction of NRPs peaked before the increased accumulation of GmNAC6 transcripts. Consistent with the delayed kinetics of GmNAC6 induction, increased levels of NRP-A and NRP-B transcripts induced promoter activation and the expression of the GmNAC6 gene.
Collectively, our results biochemically link GmNAC6 to the ER stress- and osmotic stress-integrating cell death response and show that GmNAC6 may act downstream of the NRPs.
GmNAC6; Cell death; ER stress; osmotic stress; NRPs; N-rich proteins
Various factors contribute to the urbanization of the visceral leishmaniasis (VL), including the difficulties of implementing control measures relating to the domestic reservoir. The aim of this study was to determine the prevalence of canine visceral leishmaniasis in an urban endemic area in Brazil and the factors associated with Leishmania infantum infection among seronegative and PCR-positive dogs.
A cross-sectional study was conducted in Belo Horizonte, Minas Gerais, Brazil. Blood samples were collected from 1,443 dogs. Serology was carried out by using two enzyme-linked immunosorbent assays (Biomanguinhos/FIOCRUZ/RJ and “in house”), and molecular methods were developed, including PCR-RFLP. To identify the factors associated with early stages of infection, only seronegative (n = 1,213) animals were evaluated. These animals were divided into two groups: PCR-positive (n = 296) and PCR-negative (n = 917) for L. infantum DNA. A comparison of these two groups of dogs taking into consideration the characteristics of the animals and their owners was performed. A mixed logistic regression model was used to identify factors associated with L. infantum infection.
Of the 1,443 dogs examined, 230 (15.9%) were seropositive in at least one ELISA, whereas PCR-RFLP revealed that 356 animals (24.7%) were positive for L. infantum DNA. Results indicated that the associated factors with infection were family income
PCR detected a high prevalence of L. infantum infection in dogs in an area under the Control Program of VL intervention. Socioeconomic variables, dog behavior and the knowledge of the owner regarding the vector were factors associated with canine visceral leishmaniasis (CVL). The absence of previous serological examination conducted by the control program was also associated with L. infantum infection. It is necessary to identify the risk factors associated with CVL to understand the expansion and urbanization of VL.
Visceral leishmaniasis (VL) is a disease caused by the parasite Leishmania infantum, and dogs are the most important domestic reservoirs of the agent. During recent decades, VL has expanded to large Brazilian urban centers. In the present work, we have demonstrated by using molecular techniques that the rate of canine infection as detected by serology has been considerably underestimated. Two groups of seronegative dogs (infected and non-infected according to molecular methods) were further evaluated from data obtained through interviews with owners of the animals. The factors associated with Leishmania infection in dogs were a family income of less than two minimum salaries, the knowledge of the owner regarding the vector, the dog spending most of its time in the backyard and the dog never having had a previous serological examination. Awareness regarding the factors associated with canine infection will improve health services and the understanding of the disease's expansion in urban areas.
Group G Streptococcus has been implicated as a causative agent of pharyngitis in outbreak situations, but its role in endemic disease remains elusive. We found an unexpected inverse association of Streptococcus dysgalactiae subsp. equisimilis colonization and sore throat in a study of 2,194 children of 3 to 15 years of age in Salvador, Brazil.
To identify genes associated with the clinical presentation of dengue, 50 cases of probable or possible dengue hemorrhagic fever, 236 dengue fever and 236 asymptomatic infections were genotyped for 593 single nucleotide polymorphisms in 56 genes across the type 1 interferon response pathway as well as other important candidate genes. By single locus analysis comparing dengue hemorrhagic fever with dengue fever, 11 of the 51 markers with p<0.05 were in the JAK1 gene. Five markers were significantly associated by false discovery rate criteria (q<0.20 when p<6 × 10−4). The JAK1 single nucleotide polymorphisms showed differential distribution by ethnicity and ancestry consistent with epidemiologic observations in the Americas. The association remained significant after controlling for ancestry and income. No association was observed with markers in the gene encoding CD209 (DC-SIGN). An association between dengue hemorrhagic fever and JAK1 polymorphisms is in agreement with expression profiles showing generalized decreased type 1 interferon-stimulated gene expression in these patients.
Flavivirus; population structure; interferon; genetic association; Brazil
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