In this study, we conducted an in-depth analysis to characterize potential () proteins capable of recognizing fungal β-1,3-glucans. specifically anchors curdlan or laminarin, indicating the presence of surface β-1,3-glucan-binding molecules. Using optical tweezers, strong adhesion of laminarin- or curdlan-coated beads to was observed, highlighting their adhesive properties compared to controls (characteristic time τ of 46.
View Article and Find Full Text PDFCryptosporidiosis is a disease caused by the Cryptosporidium spp parasite. As some species of Cryptosporidium have a wide host spectrum, the characterization of the pathogen at the species or genotype level is of great importance to define the sources of infection for humans and the potential for public health. This study investigated the diversity of the genus Cryptosporidium spp.
View Article and Find Full Text PDFUnlabelled: Fungal infections have increased in the last years, particularly associated to an increment in the number of immunocompromised individuals and the emergence of known or new resistant species, despite the difficulties in the often time-consuming diagnosis. The controversial efficacy of the currently available strategies for their clinical management, apart from their high toxicity and severe side effects, has renewed the interest in the research and development of new broad antifungal alternatives. These encompass vaccines and passive immunization strategies with monoclonal antibodies (mAbs), recognizing ubiquitous fungal targets, such as fungal cell wall β-1,3-glucan polysaccharides, which could be used in early therapeutic intervention without the need for the diagnosis at species level.
View Article and Find Full Text PDFFront Cell Infect Microbiol
June 2022
() is a species of free-living amoebae (FLAs) that has been widely applied as a model for the study of host-parasite interactions and characterization of environmental symbionts. The sharing of niches between and potential pathogens, such as fungi, favors associations between these organisms. Through predatory behavior, enhances fungal survival, dissemination, and virulence in their intracellular milieu, training these pathogens and granting subsequent success in events of infections to more evolved hosts.
View Article and Find Full Text PDFBackground: Cryptosporidium spp. are pathogenic protozoans that play an important role in developing diseases in the elderly, children, and immunosuppressed individuals.
Methods: The objective of this study was to detect and genetically characterize Cryptosporidium spp.
Acute schistosomiasis (AS) manifests with a broad spectrum of clinical features in pediatric populations. Diagnosis may be difficult in the absence of detectable numbers of eggs. As a result, new approaches may be required to achieve an accurate diagnosis.
View Article and Find Full Text PDFIntroduction: Cerebrospinal fluid analysis contributes to the diagnosis and neuropathogenesis of neuroinvasive arboviruses. Neurological complications caused by dengue, Zika, and chikungunya infections have high clinical relevance because of their high potential to cause death or neurological deficits. We aimed to evaluate the use of cerebrospinal fluid assays for diagnostic support in neurological disorders associated with dengue, chikungunya, and Zika infections.
View Article and Find Full Text PDFOptochin susceptibility testing is a major assay used for presumptive identification of Streptococcus pneumoniae. Still, atypical optochin-resistant (Opt) pneumococci have been reported and this phenotype has been attributed to nucleotide substitutions in the genes coding for the FFATPase. While substitutions in the atpC gene (c-subunit of ATPase) are more common and better characterized, data on mutations in the atpA (a-subunit) are still limited.
View Article and Find Full Text PDFThe cell wall is a ubiquitous structure in the fungal kingdom, with some features varying depending on the species. Additional external structures can be present, such as the capsule of (), its major virulence factor, mainly composed of glucuronoxylomannan (GXM), with anti-phagocytic and anti-inflammatory properties. The literature shows that other cryptococcal species and even more evolutionarily distant species, such as the , and can produce GXM-like polysaccharides displaying serological reactivity to GXM-specific monoclonal antibodies (mAbs), and these complex polysaccharides have similar composition and anti-phagocytic properties to cryptococcal GXM.
View Article and Find Full Text PDFObjective: To detect the frequency of (DENV), (CHIKV), and (ZIKV) in adult patients with suspected viral infection of the CNS or postinfectious syndromes living in the state of Rio de Janeiro, Brazil.
Methods: DENV, CHIKV, and ZIKV RNA by reverse transcription PCR (RT-PCR) and specific IgM antibodies were investigated in 47 CSF and serum samples of 36 adult patients suspected with viral infection or postinfectious neurologic diseases. In addition, intrathecal synthesis of anti-DENV and anti-CHIKV IgG antibodies was also evaluated using a specific antibody index.
The influence of chronic immunosuppression on the course of chikungunya virus (CHIKV) infection in recipients of solid organ transplantation (SOT) is still unsettled. Scarce data suggest that the course of CHIKV infection is generally benign in this population. In addition, the occurrence of severe atypical manifestations associated with CHIKV has not been well documented among SOT recipients.
View Article and Find Full Text PDFAspergillosis cases by have increased, along with fungal resistance to antifungals, urging the development of new therapies. Passive immunization targeting common fungal antigens, such as chitin and β-glucans, are promising and would eliminate the need of species-level diagnosis, thereby expediting the therapeutic intervention. However, these polysaccharides are poorly immunogenic.
View Article and Find Full Text PDFUnlabelled: Herpes simplex virus (HSV) is a cause of a severe disease of the central nervous system (CNS) in humans. The demonstration of specific antibodies in the cerebrospinal fluid (CSF) may contribute to the retrospective neurological diagnosis. However, the commercial immunological tests for HSV infection are for use in serum samples.
View Article and Find Full Text PDFCryptosporidium spp. is a pathogenic protozoan present in the gastrointestinal tract of several hosts. This protozoan was originally classified as within the Coccidia Class and has recently been reclassified to gregarine based on studies that observed the evolutionary phases from the process of excision and sequencing of the 18S rRNA gene.
View Article and Find Full Text PDFLike soil-transmitted helminth infections, schistosomiasis is an important neglected tropical disease (NTD) related to poverty with a major impact on public health in developing countries. Diagnosis of active infection is crucial for surveillance of controlled or post-elimination schistosomiasis areas. In addition, the use of conventional diagnostic tools in non-exposed populations (such as travelers) results in misdiagnoses in the prepatent period of infection.
View Article and Find Full Text PDFCell Microbiol
October 2019
Free-living amoebae (FLAs) are major reservoirs for a variety of bacteria, viruses, and fungi. The most studied mycophagic FLA, Acanthamoeba castellanii (Ac), is a potential environmental host for endemic fungal pathogens such as Cryptococcus spp., Histoplasma capsulatum, Blastomyces dermatitides, and Sporothrix schenckii.
View Article and Find Full Text PDFFront Immunol
July 2020
Techniques with high sensitivity and specificity are required for an accurate diagnosis in low-transmission settings, where the conventional parasitological methods are insensitive. We determined the accuracy of an up-converting phosphor-lateral flow circulating anodic antigen (UCP-LF CAA) assay in urine and serum for diagnosis in low-prevalence settings in Ceará, Brazil, before and after praziquantel treatment. Clinical samples of a total of 258 individuals were investigated by UCP-LF CAA, point-of-care-circulating cathodic antigen (POC-CCA), soluble worm antigen preparation (SWAP)-ELISA and Kato-Katz (KK); a selection of 128 stools by real-time PCR technique.
View Article and Find Full Text PDFFront Microbiol
March 2019
is a major cause of community-acquired pneumonia and meningitis, and it is also found as a commensal, colonizing the human upper respiratory tract of a portion of the human population. Its polysaccharide capsule allows the recognition of more than 90 capsular types and represents the target of the currently available pneumococcal conjugate vaccines (PCVs), such as the 10-valent (PCV10) and the 13-valent (PCV13). Penicillin non-susceptible pneumococci (PNSP) have been listed as one of the current major antimicrobial-resistant pathogen threats.
View Article and Find Full Text PDFThe taeniasis/cysticercosis complex is a zoonosis caused by the presence of the parasite Taenia solium in humans. It is considered a neglected disease that causes serious public health and economic problems in developing countries. In humans, the most common locations for the larval form are the skeletal muscles, ocular system, and the central nervous system, which is the most clinically important.
View Article and Find Full Text PDFVirulence
December 2018
Acanthamoeba castellanii (Ac) are ubiquitously distributed in nature, and by contaminating medical devices such as heart valves and contact lenses, they cause a broad range of clinical presentations to humans. Although several molecules have been described to play a role in Ac pathogenesis, including parasite host-tissue invasion and escaping of host-defense, little information is available on their mechanisms of secretion. Herein, we describe the molecular components secreted by Ac, under different protein availability conditions to simulate host niches.
View Article and Find Full Text PDFBackground: Intestinal parasitic infections are considered a serious public health problem and widely distributed worldwide, mainly in urban and rural environments of tropical and subtropical countries. Globally, soil-transmitted helminths and protozoa are the most common intestinal parasites. Blastocystis sp.
View Article and Find Full Text PDFThe majority of therapeutic strategies for mycosis require the protracted administration of antifungals, which can result in significant toxicities and have unacceptable failure rates. Hence, there is an urgent need for the development of improved therapeutic approaches, and monoclonal antibody-based drugs are potentially a powerful alternative to standard antifungals. To develop a broad antibody-like reagent against mycosis, wheat germ agglutinin (WGA) was linked to the effector Fc region of murine IgG2a.
View Article and Find Full Text PDFDengue virus (DENV) causes immune-mediated diseases. Neurological involvement represents a severe condition that is rarely observed in DENV-1 infection. Neuromyelitis optica (NMO)/NMO spectrum disorders (NMOSD) are idiopathic immune-mediated demyelinating syndromes of the central nervous system.
View Article and Find Full Text PDFStreptococcus pneumoniae can be classified in more than 90 capsular types, as traditionally determined by serological methods and more recently by PCR-based techniques. Such methods, however, can be expensive, laborious or unable to accurately discriminate among certain serotypes. Therefore, determination of capsular types, although extremely important for epidemiological purposes and for estimating the impact of pneumococcal conjugate vaccines, is mainly restricted to research laboratories, being rarely performed in the clinical setting.
View Article and Find Full Text PDFDengue, Zika and Chikungunya are emerging arboviruses and important causes of acute febrile disease in tropical areas. Although dengue does not represent a new condition, a geographic expansion over time has occurred with the appearance of severe neurological complications. Neglect has allowed the propagation of the vector (Aedes spp), which is also responsible for the transmission of other infections such as Zika and Chikungunya throughout the world.
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