“Features of two proteins of Leptospira interrogans with potential role in host-pathogen interactions”

Abstract Background Leptospirosis is considered a re-emerging infectious disease caused by pathogenic spirochaetes of the genus Leptospira. Pathogenic leptospires have the ability to survive and disseminate to multiple organs after penetrating the host. Leptospires were shown to express surface proteins that interact with the extracellular matrix (ECM) and to plasminogen (PLG). This study examined the interaction of two putative leptospiral proteins with laminin, collagen Type I, collagen Type IV, cellular fibronectin, plasma fibronectin, PLG, factor H and C4bp. Results We show that two leptospiral proteins encoded by LIC11834 and LIC12253 genes interact with laminin in a dose - dependent and saturable mode, with dissociation equilibrium constants (KD) of 367.5 and 415.4 nM, respectively. These proteins were named Lsa33 and Lsa25 (Leptospiral surface adhesin) for LIC11834 and LIC12253, respectively. Metaperiodate - treated laminin reduced Lsa25 - laminin interaction, suggesting that sugar moieties of this ligand participate in this interaction. The Lsa33 is also PLG - binding receptor, with a KD of 23.53 nM, capable of generating plasmin in the presence of an activator. Although in a weak manner, both proteins interact with C4bp, a regulator of complement classical route. In silico analysis together with proteinase K and immunoflorescence data suggest that these proteins might be surface exposed. Moreover, the recombinant proteins partially inhibited leptospiral adherence to immobilized laminin and PLG. Conclusions We believe that these multifunctional proteins have the potential to participate in the interaction of leptospires to hosts by mediating adhesion and by helping the bacteria to escape the immune system and to overcome tissue barriers. To our knowledge, Lsa33 is the first leptospiral protein described to date with the capability of binding laminin, PLG and C4bp in vitro.

TUBERCULOSIS AMONG HIV-1-INFECTED SUBJECTS IN A TERTIARY OUT-PATIENT SERVICE IN SÃO PAULO CITY, BRAZIL

TB is currently considered to be the most important infectious disease among HIV-1-infected subjects in developing countries, such as Brazil. A retrospective analysis of TB cases was performed, occurring from January 1995 to December 2010 in our cohort of 599 HIV positive patients. The primary outcome was the occurrence of active TB. Forty-one TB cases were diagnosed over this period of 16 years, among 599 HIV positive patients in an open cohort setting in the city of Sao Paulo, Brazil. All-time lowest mean CD4 T cell count at the time of TB diagnosis was 146 and 186 cells/mm3, respectively. The mean HIV viral load was 5.19 log10 copies/mL, and 59% of the patients were on HAART. TB incidence was 1.47 per 100 person-years, for a total follow-up time of 2775 person-years. The probability of surviving up to 10 years after diagnosis was 75% for TB patients as opposed to 96% for patients with other, non-TB opportunistic diseases (p = 0.03). TB can be considered a public health problem among people living with HIV in Brazil despite of the widespread use of antiretrovirals for the treatment of HIV infection/AIDS.

Antibody levels to hantavirus in inhabitants of western Santa Catarina State, Brazil

Hantavirus cardiopulmonary syndrome (HCPS) is an infectious disease caused by hantaviruses of the family Bunyaviridae, and is transmitted by aerosols of excreta of infected rodents. The aim of the present study was to determine antibody levels to hantavirus in the population that lives at frontier of Brazil and Argentina. Participated of the study 405 individuals living in the municipalities of Bandeirante, Santa Helena, Princesa and Tunapolis, state of Santa Catarina, Brazil. IgG antibodies to hantavirus were analyzed in sera by an ELISA that uses a recombinant N protein of Araraquara hantavirus as antigen. The results were also confirmed by immunofluorescent test. Eight individuals showed antibodies to hantavirus (1.97% positivity), with serum titers ranging from 100 to 800. Six seropositives were males, older than 30 years and farmers. Our results reinforce previous data on hantavirus circulation and human infections in the southern border of Brazil with Argentina.

Quality of life of patients with paucibacillary leprosy

BACKGROUND: Leprosy, an infectious disease caused by Mycobacterium leprae, can affect the skin and the peripheral nervous system and, depending on the level of involvement, it can lead to severe deformities. Leprosy is classified into two major groups: paucibacillary (up to five lesions) and multibacillary (more than five lesions). The deformities that appear during the progress of the disease can affect the quality of life. OBJECTIVE: To assess quality of life of patients with paucibacillary leprosy diagnosed and treated early in the outpatients' clinic. METHODS: The Dermatology Life Quality Index questionnaire and ShortForm36 were applied to 49 outpatients undergoing treatment at the Leprosy Multidisciplinary Group of the Hospital das Clínicas of the Faculdade de Medicina of the Universidade de São Paulo. RESULTS: The majority of the patients (63%) did not show impairment of the quality of life, according to the results obtained by the Dermatology Life Quality Index questionnaire. In the questionnaire Short Form-36, the scores assessed showed slight impairment of the quality of life. CONCLUSION: On this study, we can conclude that this group of patients, with paucibacillary leprosy, did not show important impairment of the quality of life. Therefore we can conclude that the earlier the diagnosis and the treatment the lesser the influence on the quality of life.

Assessment of depression in medical patients: a systematic review of the utility of the beck depression inventory-II

To perform a systematic review of the utility of the Beck Depression Inventory for detecting depression in medical settings, this article focuses on the revised version of the scale (Beck Depression Inventory-II), which was reformulated according to the DSM-IV criteria for major depression. We examined relevant investigations with the Beck Depression Inventory-II for measuring depression in medical settings to provide guidelines for practicing clinicians. Considering the inclusion and exclusion criteria seventy articles were retained. Validation studies of the Beck Depression Inventory-II, in both primary care and hospital settings, were found for clinics of cardiology, neurology, obstetrics, brain injury, nephrology, chronic pain, chronic fatigue, oncology, and infectious disease. The Beck Depression Inventory-II showed high reliability and good correlation with measures of depression and anxiety. Its threshold for detecting depression varied according to the type of patients, suggesting the need for adjusted cut-off points. The somatic and cognitive-affective dimension described the latent structure of the instrument. The Beck Depression Inventory-II can be easily adapted in most clinical conditions for detecting major depression and recommending an appropriate intervention. Although this scale represents a sound path for detecting depression in patients with medical conditions, the clinician should seek evidence for how to interpret the score before using the Beck Depression Inventory-II to make clinical decisions

MyD88 signaling is directly involved in the development of murine placental Malaria

Malaria is a widespread infectious disease caused by the parasite Plasmodium. During pregnancy, malaria infection leads to a range of complications that can affect both the mother and fetus, including stillbirth, infant mortality, and low birth weight. In this study, we utilized a mouse model of placental malaria (PM) infection to determine the importance of the protein MyD88 in the host immune response to Plasmodium during pregnancy. Initially, we demonstrated that Plasmodium berghei NK65GFP adhered to placental tissue via chondroitin sulfate A and induced PM in mice with a C57BL/6 genetic background. To evaluate the involvement of MyD88 in the pathology of PM, we performed a histopathological analysis of placentas obtained from MyD88(-/-) and wild-type (WT) mice following infection on the 19th gestational day. Our data demonstrated that the detrimental placental alterations observed in the infected mice were correlated with the expression of MyD88. Moreover, in the absence of this protein, production of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) was significantly reduced in the infected mice. More importantly, in contrast to fetuses from infected WT mice, which exhibited a reduction in body weight, the fetuses from infected MyD88(-/-) mice did not display significant weight loss compared to their noninfected littermates. In addition, we observed a decrement of maternal care associated with malaria infection, which was attenuated in the MyD88-deficient mice. Collectively, the results of this study illustrate the pivotal importance of the MyD88 signaling pathway in the pathogenesis of placental malaria, thus presenting new possibilities for targeting MyD88 in therapeutic interventions.

The role of the NadR regulator during infection and its implication for the coverage of a new Meningococcus B vaccine

Background: Neisseria meningitides represents a major cause of meningitis and sepsis. The meningococcal regulator NadR was previously shown to repress the expression of the Neisserial Adhesin A (NadA) and play a major role in its phase-variation. NadA is a surface exposed protein involved in epithelial cell adhesion and colonization and a major component of 4CMenB, a novel vaccine to prevent meningococcus serogroup B infection. The NadR mediated repression of NadA is attenuated by 4-HPA, a natural molecule released in human saliva. Results: In this thesis we investigated the global role of NadR during meningogoccal infection, identifying through microarray analysis the NadR regulon. Two distinct types of NadR targets were identified, differing in their promoter architectures and 4HPA responsive activities: type I are induced, while type II are co-repressed in response to the same 4HPA signal. We then investigate the mechanism of regulation of NadR by 4-HPA, generating NadR mutants and identifying classes or residues involved in either NadR DNA binding or 4HPA responsive activities. Finally, we studied the impact of NadR mediated repression of NadA on the vaccine coverage of 4CMenB. A selected MenB strains is not killed by sera from immunized infants when the strain is grown in vitro, however, in an in vivo passive protection model, the same sera protected infant rats from bacteremia. Finally, using bioluminescent reporters, nadA expression in the infant rat model was induced in vivo at 3 h post-infection. Conclusions: Our results suggest that NadR coordinates a broad transcriptional response to signals present in the human host, enabling the meningococcus to adapt to the relevant host niche. During infectious disease the effect of the same signal on NadR changes between different targets. In particular NadA expression is induced in vivo, leading to efficient killing of meningococcus by anti-NadA antibodies elicited by the 4CMenB vaccine.

Valutazione della proteinuria e del follow-up clinico e clinicopatologico in cani affetti da Leishmaniosi canina

Introduzione: la leishmaniosi canina (CanL) è una malattia infettiva, trasmessa da vettore e sostenuta da un protozoo, la Leishmania infantum. La CanL ha assunto sempre più importanza sia in medicina veterinaria che in medicina umana. La leishmaniosi è fortemente associata allo sviluppo di una nefropatia cronica. Disegno dello studio: studio di coorte retrospettivo. Obiettivo: individuare le alterazioni clinico-patologiche prevalenti al momento dell’ammissione e durante il follow-up del paziente, per identificare quelle con un valore prognostico maggiore. Materiali e metodi: 167 cani, per un totale di 187 casi trattati, con diagnosi sierologica e/o citologica di Leishmaniosi e dati ematobiochimici completi, elettroforesi sierica, analisi delle urine e biochimica urinaria comprensiva di proteinuria (UPC) ed albuminuria (UAC), profilo coagulativo (ATIII, d-Dimeri, Fibrinogeno) e marker d’infiammazione (CRP). Dei pazienti inclusi è stato seguito il follow-up clinico e clinicopatologico per un periodo di tempo di due anni e sono stati considerati. Risultati: Le alterazione clinicopatologiche principali sono state anemia (41%), iperprotidemia (42%), iperglobulinemia (75%), ipoalbuminemia (66%), aumento della CRP (57%), incremento dell’UAC (78%), aumento dell’UPC (70%), peso specifico inadeguato (54%) e riduzione dell’ATIII (52%). Il 37% dei pazienti non era proteinurico e di questi il 27% aveva già un’albuminuria patologica. Il 38% dei pazienti aveva una proteinuria nefrosica (UPC>2,5) e il 22% era iperazotemico. I parametri clinicopatologici hanno mostrato una tendenza a rientrare nella normalità dopo il 90° giorno di follow-up. La creatinina sierica, tramite un analisi multivariata, è risultata essere il parametro correlato maggiormente con l’outcome del paziente. Conclusione: i risultati ottenuti in funzione dell’outcome dei pazienti hanno mostrato che i soggetti deceduti durante il follow-up, al momento dell’ammissione avevano valori di creatinina, UPC e UAC più elevati e ingravescenti. Inoltre l’UAC può venire considerato un marker precoce di nefropatia e la presenza di iperazotemia all’ammissione, in questi pazienti, ha un valore prognostico negativo.

Identifizierung chemischer Transportinhibitoren zur Modulation (patho)biologischer Genprodukte

Die intrazelluläre Lokalisation von Proteinen und Makromolekülen unterliegt in Eukaryoten einer strengen Regulation. Insbesondere erlaubt die Kompartimentierung eukaryotischer Zellen in Zellkern und Zytoplasma den simultanen Ablauf räumlich getrennter biochemischer Reaktionen, und damit die unabhängige Regulation zellulärer Programme. Da trotz intensiver Forschungsbemühungen bis dato die molekularen Details sowie die (patho)biologische Bedeutung von Kern-Zytoplasma-Transportprozessen noch immer nicht vollkommen verstanden sind, wurde im Rahmen der vorliegenden Arbeit ein Fokus auf die Identifizierung von chemischen Transportinhibitoren gelegt. Das zu diesem Zweck entwickelte Translokations-Biosensor-System basiert auf der Kombination von autofluoreszierenden Proteinen, sowie spezifisch ausgewählten Kernexport- und Kernimportsignalen. Nach Etablierung geeigneter Zellmodelle, die effizient und stabil die Translokations-Biosensoren exprimieren, wurde die 17 000 Substanzen umfassende Bibliothek der ChemBioNet-Initiative nach Kernexportinhibitoren mittels einer Fluoreszenzmikroskopie-basierten Hochdurchsatzanalyse-Plattform durchmustert. Zunächst wurden Translokations-Algorithmen, welche eine zuverlässige automatisierte Erkennung von Zellkern und Zytoplasma erlauben, optimiert. Im Folgenden konnten acht neue niedermolekulare Kernexport-Inhibitoren identifiziert werden, die sich in der Stärke, der Geschwindigkeit, sowie in der Beständigkeit der vermittelten Inhibition unterscheiden. Die Aktivität der Inhibitoren konnte auf den isolierten nukleären Exportsignalen (NES) von HIV-1 Rev und Survivin als auch auf den entsprechenden Volllängeproteinen mittels Mikroinjektionsexperimenten sowie durch umfassende in vitro und biochemische Methoden bestätigt werden. Zur Untersuchung der funktionellen Einheiten der Inhibitoren wurden homologe Substanzen auf Ihre Aktivität hin getestet. Dabei konnten für die Aktivität wichtige chemische Gruppen definiert werden. Alle Substanzen stellen neue Inhibitoren des Crm1-abhängigen Exports dar und zeigen keine nachweisbare NES-Selektivität. Interessanterweise konnte jedoch eine zytotoxische und Apoptose-induzierende Wirkung auf verschiedene Krebszellarten festgestellt werden. Da diese Wirkung unabhängig vom p53-Status der Tumorzellen ist und die Inhibitoren C3 und C5 die Vitalität nicht-maligner humaner Zellen signifikant weniger beeinträchtigen, wurden diese Substanzen zum internationalen Patent angemeldet. Da der nukleäre Export besonders für Tumorzellen einen wichtigen Überlebenssignalweg darstellt, könnte dessen reversible Hemmung ausgenutzt werden, um besonders in Kombination mit gängigen Krebstherapien eine therapeutisch relevante Tumorinhibition zu erzeugen. Eine weitere Anwendungsmöglichkeit der neuen Exportinhibitoren ist auf dem Gebiet der Infektionskrankheiten zu sehen, da auch die Aktivität des essentiellen HIV-1 Rev-Proteins inhibiert wird. Zusätzlich konnte in der Arbeit gezeigt werden, dass der zelluläre Kofaktor des Crm1-abhängigen Exports des HIV-1 Rev-Proteins, die RNA-Helikase DDX3, ein eigenes NES enthält. Der Nachweis einer direkten Interaktion des HIV-1 Rev- mit dem DDX3-Protein impliziert, dass multiple Angriffstellen für chemische Modulatoren hinsichtlich einer antiviralen Therapie gegeben sind. Da die Vielfalt des chemischen Strukturraums es unmöglich macht diesen experimentell vollständig zu durchmustern, wurden im Rahmen dieser Arbeit auch Naturstoffe als vielversprechende Wirkstoffquelle untersucht. Um zukünftig umfassend bioaktive Substanzen aus diesen hochkomplexen Stoffgemischen experimentell identifizieren zu können, wurde eine Fluoreszenzmikroskopie-basierte Hochdurchsatzanalyse-Plattform am Mainz Screening Center (MSC) etabliert. Damit konnte bereits ein weiterer, bisher unbekannter Exportinhibitor aus Cyphellopsis anomala identifiziert werden. Neben einer Anwendung dieser Substanz als chemisches Werkzeug zur Aufklärung der Regulation von Transportvorgängen, stellt sich auch die evolutionsbiologisch relevante Frage, wie es dem Pilzproduzenten gelingt die Blockierung des eigenen Kernexports zu umgehen. Weiterführende Projekte müssen sich neben der Aufklärung der molekularen Wirkmechanismen der gefundenen Substanzen mit der Identifizierung spezifischer chemischer „Funktionseinheiten“ beschäftigen. Neben einem verbesserten mechanistischen Verständnis von Transportvorgängen stellen die erarbeiteten Transportinhibitoren Vorstufen zur Weiterentwicklung möglicher Wirkstoffe dar. Die im Rahmen dieser Arbeit etablierte Technologie-Plattform und molekularen Werkzeuge stellen darüber hinaus eine wichtige Voraussetzung dar, um eine systematische Suche nach möglichen Wirkstoffen im Forschungsfeld der „Chemischen Biomedizin“ voranzutreiben.

Oropharyngeal lesions and cervical lymphadenopathy: syphilis is a differential diagnosis that is still relevant

Syphilis (lues), a chronic infectious disease caused by Treponema pallidum, has been increasing in incidence during the last few years. Therefore, while clinically it is often not suspected, syphilis is increasingly becoming a differential diagnosis in routine pathology.

Heterogeneity in vaccination coverage explains the size and occurrence of measles epidemics in German surveillance data

The objective of this study was to characterize empirically the association between vaccination coverage and the size and occurrence of measles epidemics in Germany. In order to achieve this we analysed data routinely collected by the Robert Koch Institute, which comprise the weekly number of reported measles cases at all ages as well as estimates of vaccination coverage at the average age of entry into the school system. Coverage levels within each federal state of Germany are incorporated into a multivariate time-series model for infectious disease counts, which captures occasional outbreaks by means of an autoregressive component. The observed incidence pattern of measles for all ages is best described by using the log proportion of unvaccinated school starters in the autoregressive component of the model.

Retinitis and optic neuritis in a child with chickenpox: case report and review of literature

In immunocompetent individuals, necrotizing retinopathy is a rare complication of chickenpox. Herein, we report on a 3-year-old immunocompetent boy who developed retinitis and optic neuritis 3 days after the onset of chickenpox and compare the findings to published cases. Since macula and optic nerve were affected, visual acuity remained poor. An early diagnosis and treatment of ocular manifestations in chickenpox is imperative for the preservation of a residual visual function and prevention of blinding secondary complications.

Comparison of real-time polymerase chain reaction and DNA-strip technology in microbiological evaluation of periodontitis treatment

The impact of a semiquantitative commercially available test based on DNA-strip technology (microIDent®, Hain Lifescience, Nehren, Germany) on diagnosis and treatment of severe chronic periodontitis of 25 periodontitis patients was evaluated in comparison with a quantitative in-house real-time PCR. Subgingival plaque samples were collected at baseline as well as at 3, 6, and 12 months later. After extracting DNA, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and several other periodontopathogens were determined by both methods. The results obtained by DNA-strip technology were analyzed semiquantitatively and additionally quantitatively by densitometry. The results for the 4 major periodontopathogenic bacterial species correlated significantly between the 2 methods. Samples detecting a high bacterial load by one method and negative by the other were always found in less than 2% of the total samples. Both technologies showed the impact of treatment on microflora. Especially the semiquantitative DNA-strip technology clearly analyzed the different loads of periodontopathogens after therapy and is useful in microbial diagnostics for patients in dental practices.

Experimental Infection of Bats with Geomyces destructans Causes White-nose Syndrome

White-nose syndrome (WNS) has caused recent catastrophic declines among multiple species of bats in eastern North America1, 2. The disease’s name derives from a visually apparent white growth of the newly discovered fungus Geomyces destructans on the skin (including the muzzle) of hibernating bats1, 3. Colonization of skin by this fungus is associated with characteristic cutaneous lesions that are the only consistent pathological finding related to WNS4. However, the role of G. destructans in WNS remains controversial because evidence to implicate the fungus as the primary cause of this disease is lacking. The debate is fuelled, in part, by the assumption that fungal infections in mammals are most commonly associated with immune system dysfunction5, 6, 7. Additionally, the recent discovery that G. destructans commonly colonizes the skin of bats of Europe, where no unusual bat mortality events have been reported8, 9, 10, has generated further speculation that the fungus is an opportunistic pathogen and that other unidentified factors are the primary cause of WNS11, 12. Here we demonstrate that exposure of healthy little brown bats (Myotis lucifugus) to pure cultures of G. destructans causes WNS. Live G. destructans was subsequently cultured from diseased bats, successfully fulfilling established criteria for the determination ofG. destructans as a primary pathogen13. We also confirmed that WNS can be transmitted from infected bats to healthy bats through direct contact. Our results provide the first direct evidence that G. destructans is the causal agent of WNS and that the recent emergence of WNS in North America may represent translocation of the fungus to a region with a naive population of animals8. Demonstration of causality is an instrumental step in elucidating the pathogenesis14 and epidemiology15 of WNS and in guiding management actions to preserve bat populations against the novel threat posed by this devastating infectious disease.

Frequent Arousal from Hibernation Linked to Severity of Infection and Mortality in Bats with White-Nose Syndrome

White-nose syndrome (WNS), an emerging infectious disease that has killed over 5.5 million hibernating bats, is named for the causative agent, a white fungus (Geomyces destructans (Gd)) that invades the skin of torpid bats. During hibernation, arousals to warm (euthermic) body temperatures are normal but deplete fat stores. Temperature-sensitive dataloggers were attached to the backs of 504 free-ranging little brown bats (Myotis lucifugus) in hibernacula located throughout the northeastern USA. Dataloggers were retrieved at the end of the hibernation season and complete profiles of skin temperature data were available from 83 bats, which were categorized as: (1) unaffected, (2) WNS-affected but alive at time of datalogger removal, or (3) WNS-affected but found dead at time of datalogger removal. Histological confirmation of WNS severity (as indexed by degree of fungal infection) as well as confirmation of presence/absence of DNA from Gd by PCR was determined for 26 animals. We demonstrated that WNS-affected bats aroused to euthermic body temperatures more frequently than unaffected bats, likely contributing to subsequent mortality. Within the subset of WNS-affected bats that were found dead at the time of datalogger removal, the number of arousal bouts since datalogger attachment significantly predicted date of death. Additionally, the severity of cutaneous Gd infection correlated with the number of arousal episodes from torpor during hibernation. Thus, increased frequency of arousal from torpor likely contributes to WNS-associated mortality, but the question of how Gd infection induces increased arousals remains unanswered.