Rapid Diagnostic Tests for Trypanosoma cruzi Infection: Field Evaluation of Two Registered Kits in a Region of Endemicity and a Region of Nonendemicity in Argentina

ABSTRACT Infection by Trypanosoma cruzi (Chagas disease [ChD]) affects around 7 million people in the Americas, most of whom are unaware of their status due to lack of clinical manifestations and poor access to diagnosis. Rapid diagnostic tests (RDTs) are widely used for screening for different infections (HIV, hepatitis B, and syphilis), and their application for ChD would facilitate access to diagnosis, especially in remote areas where health services have scarce resources. We conducted a prospective intervention study in 2018 to evaluate in the field two in vitro RDTs for ChD, authorized by the National Administration of Medicaments, Aliments, and Medical Technologies of Argentina (ANMAT), in areas of endemicity and nonendemicity in Argentina. We recruited 607 volunteers older than 18 years in Salta province and the city of Buenos Aires. The RDTs Ab Standard Diagnostics SD Bioline (SD) and Check Chagas Wiener Lab (WL) were performed in situ with whole-blood samples, and confirmatory serology was done at a reference center. The rate of infection with T. cruzi was 17.8% (108/607). The SD test showed 97.2% sensitivity (95% confidence interval [CI], 93.5 to 100) and 91.7% specificity (95% CI, 96.2 to 99.2%), and the WL test showed 93.4% sensitivity (95% CI, 88.2 to 98.6%) and 99.1% specificity (95% CI, 91.9 to 100%). The sensitivity and specificity for the two RDTs tested were higher than previously reported. These results encourage the use of the tested RDTs in Salta province and for further field studies for the implementation of these RDTs in other epidemiological scenarios. This will be very important to improve access to diagnosis of Chagas and its clinical management as a neglected disease, especially in remote areas with health access barriers.

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Neurotrophin Receptor TrkC Is an Entry Receptor for Trypanosoma cruzi in Neural, Glial, and Epithelial Cells

Infection and Immunity ◽

10.1128/iai.05403-11 ◽

2011 ◽

Vol 79 (10) ◽

pp. 4081-4087 ◽

Cited By ~ 16

Author(s):

Craig Weinkauf ◽

Ryan Salvador ◽

Mercio PereiraPerrin

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Mammalian Cells ◽

Chinese Hamster ◽

Neuronal Cell ◽

Host Cells ◽

Neurotrophin Receptor ◽

Content Type

ABSTRACTTrypanosoma cruzi, the agent of Chagas' disease, infects a variety of mammalian cells in a process that includes multiple cycles of intracellular division and differentiation starting with host receptor recognition by a parasite ligand(s). Earlier work in our laboratory showed that the neurotrophin-3 (NT-3) receptor TrkC is activated byT. cruzisurfacetrans-sialidase, also known as parasite-derived neurotrophic factor (PDNF). However, it has remained unclear whether TrkC is used byT. cruzito enter host cells. Here, we show that a neuronal cell line (PC12-NNR5) relatively resistant toT. cruzibecame highly susceptible to infection when overexpressing human TrkC but not human TrkB. Furthermore,trkCtransfection conferred an ∼3.0-fold intracellular growth advantage. Sialylation-deficient Chinese hamster ovarian (CHO) epithelial cell lines Lec1 and Lec2 also became much more permissive toT. cruziafter transfection with thetrkCgene. Additionally, NT-3 specifically blockedT. cruziinfection of the TrkC-NNR5 transfectants and of naturally permissive TrkC-bearing Schwann cells and astrocytes, as did recombinant PDNF. Two specific inhibitors of Trk autophosphorylation (K252a and AG879) and inhibitors of Trk-induced MAPK/Erk (U0126) and Akt kinase (LY294002) signaling, but not an inhibitor of insulin-like growth factor 1 receptor, abrogated TrkC-mediated cell invasion. Antibody to TrkC blockedT. cruziinfection of the TrkC-NNR5 transfectants and of cells that naturally express TrkC. The TrkC antibody also significantly and specifically reduced cutaneous infection in a mouse model of acute Chagas' disease. TrkC is ubiquitously expressed in the peripheral and central nervous systems, and in nonneural cells infected byT. cruzi, including cardiac and gastrointestinal muscle cells. Thus, TrkC is implicated as a functional PDNF receptor in cell entry, independently of sialic acid recognition, mediating broadT. cruziinfection bothin vitroandin vivo.

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Nitro/Nitrosyl-Ruthenium Complexes Are Potent and Selective Anti-Trypanosoma cruzi Agents Causing Autophagy and Necrotic Parasite Death

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02765-14 ◽

2014 ◽

Vol 58 (10) ◽

pp. 6044-6055 ◽

Cited By ~ 13

Author(s):

Tanira M. Bastos ◽

Marília I. F. Barbosa ◽

Monize M. da Silva ◽

José W. da C. Júnior ◽

Cássio S. Meira ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Inhibitory Concentration ◽

Content Type ◽

X Ray ◽

X Ray Crystallography ◽

Ruthenium Nitrosyl ◽

Index Analysis ◽

Antiparasitic Drug ◽

Drug Complex

ABSTRACTcis-[RuCl(NO2)(dppb)(5,5′-mebipy)] (complex 1),cis-[Ru(NO2)2(dppb)(5,5′-mebipy)] (complex 2),ct-[RuCl(NO)(dppb)(5,5′-mebipy)](PF6)2(complex 3), andcc-[RuCl(NO)(dppb)(5,5′-mebipy)](PF6)2(complex 4), where 5,5′-mebipy is 5,5′-dimethyl-2,2′-bipyridine and dppb is 1,4-bis(diphenylphosphino)butane, were synthesized and characterized. The structure of complex 2 was determined by X-ray crystallography. These complexes exhibited a higher anti-Trypanosoma cruziactivity than benznidazole, the current antiparasitic drug. Complex 3 was the most potent, displaying a 50% effective concentration (EC50) of 2.1 ± 0.6 μM against trypomastigotes and a 50% inhibitory concentration (IC50) of 1.3 ± 0.2 μM against amastigotes, while it displayed a 50% cytotoxic concentration (CC50) of 51.4 ± 0.2 μM in macrophages. It was observed that the nitrosyl complex 3, but not its analog lacking the nitrosyl group, releases nitric oxide into parasite cells. This release has a diminished effect on the trypanosomal protease cruzain but induces substantial parasite autophagy, which is followed by a series of irreversible morphological impairments to the parasites and finally results in cell death by necrosis. In infected mice, orally administered complex 3 (five times at a dose of 75 μmol/kg of body weight) reduced blood parasitemia and increased the survival rate of the mice. Combination index analysis of complex 3 indicated that itsin vitroactivity against trypomastigotes is synergic with benznidazole. In addition, drug combination enhanced efficacy in infected mice, suggesting that ruthenium-nitrosyl complexes are potential constituents for drug combinations.

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Is Staphylococcus lugdunensis Significant in Clinical Samples?

Journal of Clinical Microbiology ◽

10.1128/jcm.00846-17 ◽

2017 ◽

Vol 55 (11) ◽

pp. 3167-3174 ◽

Cited By ~ 26

Author(s):

Xavier Argemi ◽

Yves Hansmann ◽

Philippe Riegel ◽

Gilles Prévost

Keyword(s):

Pathogenic Bacteria ◽

Clinical Manifestations ◽

Clinical Samples ◽

Opportunistic Pathogens ◽

Coagulase Negative Staphylococci ◽

Staphylococcus Lugdunensis ◽

Content Type ◽

Severe Infections ◽

Microbiological Data

ABSTRACTThe implication of coagulase-negative staphylococci in human diseases is a major issue, particularly in hospital settings wherein these species often act as opportunistic pathogens. In addition, some coagulase-negative staphylococci such asS. lugdunensishave emerged as pathogenic bacteria, implicated in severe infections, particularly, osteoarticular infections, foreign-body-associated infections, bacteremia, and endocarditis.In vitrostudies have shown the presence of several putative virulence factors such as adhesion factors, biofilm production, and proteolytic factors that might explain clinical manifestations. Taken together, the clinical and microbiological data might change the way clinicians and microbiologists look atS. lugdunensisin clinical samples.

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Trypanosoma cruzi Ikiakarora (TcIII) Draft Genome Sequence

Microbiology Resource Announcements ◽

10.1128/mra.00453-20 ◽

2020 ◽

Vol 9 (27) ◽

Author(s):

Inmaculada Gómez ◽

Alberto Rastrojo ◽

Fabián Lorenzo-Díaz ◽

Francisco José Sánchez-Luque ◽

Francisco Macías ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Variability ◽

Trypanosoma Cruzi ◽

Geographical Distribution ◽

Genome Sequence ◽

Draft Genome ◽

Clinical Manifestations ◽

Sylvatic Cycle ◽

Content Type ◽

Discrete Typing Unit

ABSTRACT Trypanosoma cruzi shows a genetic diversity that has been associated with the variability of clinical manifestations, geographical distribution, and preferential parasite-vector interactions. In an effort to better understand this genetic variability, here, the draft genome of T. cruzi strain Ikiakarora (discrete typing unit TcIII), which has been associated with the sylvatic cycle, is reported.

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Field Evaluation of Cholkit Rapid Diagnostic Test for Vibrio Cholerae O1 During a Cholera Outbreak in Malawi, 2018

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa493 ◽

2020 ◽

Vol 7 (11) ◽

Author(s):

Innocent Chibwe ◽

Watipaso Kasambara ◽

Mathews Kagoli ◽

Harry Milala ◽

Charity Gondwe ◽

...

Keyword(s):

Vibrio Cholerae ◽

Diagnostic Test ◽

Rapid Diagnostic Test ◽

Diagnostic Tests ◽

Field Evaluation ◽

Rapid Diagnostic Tests ◽

Cholera Outbreak ◽

Vibrio Cholerae O1

Abstract Rapid diagnostic tests (RDTs) for cholera are an important emerging tool for surveillance, yet the currently available tests have several limitations. We assess the performance of a new RDT, Cholkit, during a cholera outbreak in Malawi compared with culture and find a sensitivity of 93.0% (95% CI, 83.0%–98.1%) and a specificity of 95.7% (95% CI, 78.1%–100.0%).

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Efficacy of Novel Pyrazolone Phosphodiesterase Inhibitors in Experimental Mouse Models of Trypanosoma cruzi

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00414-20 ◽

2020 ◽

Vol 64 (9) ◽

Author(s):

Julianna Siciliano de Araújo ◽

Cristiane França da Silva ◽

Denise da Gama Jaén Batista ◽

Aline Nefertiti ◽

Ludmila Ferreira de Almeida Fiuza ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Phosphodiesterase Inhibitors ◽

Biological Properties ◽

Host Cells ◽

Mammalian Host ◽

Intracellular Camp ◽

Additive Interaction ◽

Content Type

ABSTRACT Pyrazolones are heterocyclic compounds with interesting biological properties. Some derivatives inhibit phosphodiesterases (PDEs) and thereby increase the cellular concentration of cyclic AMP (cAMP), which plays a vital role in the control of metabolism in eukaryotic cells, including the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease (CD), a major neglected tropical disease. In vitro phenotypic screening identified a 4-bromophenyl-dihydropyrazole dimer as an anti-T. cruzi hit and 17 novel pyrazolone analogues with variations on the phenyl ring were investigated in a panel of phenotypic laboratory models. Potent activity against the intracellular forms (Tulahuen and Y strains) was obtained with 50% effective concentration (EC50) values within the 0.17 to 3.3 μM range. Although most were not active against bloodstream trypomastigotes, an altered morphology and loss of infectivity were observed. Pretreatment of the mammalian host cells with pyrazolones did not interfere with infection and proliferation, showing that the drug activity was not the result of changes to host cell metabolism. The pyrazolone NPD-227 increased the intracellular cAMP levels and was able to sterilize T. cruzi-infected cell cultures. Thus, due to its high potency and selectivity in vitro, and its additive interaction with benznidazole (Bz), NPD-227 was next assessed in the acute mouse model. Oral dosing for 5 days of NPD-227 at 10 mg/kg + Bz at 10 mg/kg not only reduced parasitemia (>87%) but also protected against mortality (>83% survival), hence demonstrating superiority to the monotherapy schemes. These data support these pyrazolone molecules as potential novel therapeutic alternatives for Chagas disease.

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Inhibition of Host Cell Lysosome Spreading by Trypanosoma cruzi Metacyclic Stage-Specific Surface Molecule gp90 Downregulates Parasite Invasion

Infection and Immunity ◽

10.1128/iai.00302-17 ◽

2017 ◽

Vol 85 (9) ◽

Cited By ~ 8

Author(s):

João Paulo Ferreira Rodrigues ◽

Guilherme Hideki Takahashi Sant'ana ◽

Maria Aparecida Juliano ◽

Nobuko Yoshida

Keyword(s):

Trypanosoma Cruzi ◽

Hela Cell ◽

Specific Surface ◽

Host Cell ◽

Cell Invasion ◽

Target Cell ◽

Content Type ◽

Terminal Domain ◽

Successful Infection

ABSTRACT Successful infection by Trypanosoma cruzi, the agent of Chagas' disease, is critically dependent on host cell invasion by metacyclic trypomastigote (MT) forms. Two main metacyclic stage-specific surface molecules, gp82 and gp90, play determinant roles in target cell invasion in vitro and in oral T. cruzi infection in mice. The structure and properties of gp82, which is highly conserved among T. cruzi strains, are well known. Information on gp90 is still rather sparse. Here, we attempted to fill that gap. gp90, purified from poorly invasive G strain MT and expressing gp90 at high levels, inhibited HeLa cell lysosome spreading and the gp82-mediated internalization of a highly invasive CL strain MT expressing low levels of a diverse gp90 molecule. A recombinant protein containing the conserved C-terminal domain of gp90 exhibited the same properties as the native G strain gp90: it counteracted the host cell lysosome spreading induced by recombinant gp82 and exhibited an inhibitory effect on HeLa cell invasion by CL strain MT. Assays to identify the gp90 sequence associated with the property of downregulating MT invasion, using synthetic peptides spanning the gp90 C-terminal domain, revealed the sequence GVLYTADKEW. These data, plus the findings that lysosome spreading was induced upon HeLa cell interaction with CL strain MT, but not with G strain MT, and that in mixed infection CL strain MT internalization was inhibited by G strain MT, suggest that the inhibition of target cell lysosome spreading is the mechanism by which the gp90 molecule exerts its downregulatory role.

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Naegleria fowleri: Pathogenesis, Diagnosis, and Treatment Options

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01293-15 ◽

2015 ◽

Vol 59 (11) ◽

pp. 6677-6681 ◽

Cited By ~ 66

Author(s):

Eddie Grace ◽

Scott Asbill ◽

Kris Virga

Keyword(s):

Case Reports ◽

Treatment Options ◽

Clinical Manifestations ◽

Naegleria Fowleri ◽

Content Type ◽

High Profile ◽

Free Living Amoeba ◽

Nægleria Fowleri ◽

Amoebic Meningoencephalitis

ABSTRACTNaegleria fowlerihas generated tremendous media attention over the last 5 years due to several high-profile cases. Several of these cases were followed very closely by the general public.N. fowleriis a eukaryotic, free-living amoeba belonging to the phylum Percolozoa.Naegleriaamoebae are ubiquitous in the environment, being found in soil and bodies of freshwater, and feed on bacteria found in those locations. WhileN. fowleriinfection appears to be quite rare compared to other diseases, the clinical manifestations of primary amoebic meningoencephalitis are devastating and nearly always fatal. Due to the rarity ofN. fowleriinfections in humans, there are no clinical trials to date that assess the efficacy of one treatment regimen over another. Most of the information regarding medication efficacy is based on either case reports orin vitrostudies. This review will discuss the pathogenesis, diagnosis, pharmacotherapy, and prevention ofN. fowleriinfections in humans, including a brief review of all survivor cases in North America.

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Enantiomers of Nifurtimox Do Not Exhibit Stereoselective Anti-Trypanosoma cruzi Activity, Toxicity, or Pharmacokinetic Properties

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.05139-14 ◽

2015 ◽

Vol 59 (6) ◽

pp. 3645-3647 ◽

Cited By ~ 1

Author(s):

Carolina B. Moraes ◽

Karen L. White ◽

Stéphanie Braillard ◽

Catherine Perez ◽

Junghyun Goo ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Murine Model ◽

Therapeutic Benefit ◽

Racemic Mixture ◽

Content Type ◽

Pharmacokinetic Properties

ABSTRACTWith the aim of improving the available drugs for the treatment of Chagas disease, individual enantiomers of nifurtimox were characterized. The results indicate that the enantiomers are equivalent in theirin vitroactivity against a panel ofTrypanosoma cruzistrains;in vivoefficacy in a murine model of Chagas disease;in vitrotoxicity and absorption, distribution, metabolism, and excretion characteristics; andin vivopharmacokinetic properties. There is unlikely to be any therapeutic benefit of an individual nifurtimox enantiomer over the racemic mixture.

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