Succinyl-CoA Synthetase: New Antigen Candidate of Bartonella bacilliformis

BACKGROUND: Bartonella bacilliformis is the causative agent of Carrion's disease, a neglected illness with mortality rates of 40-85% in the absence of treatment. The lack of a diagnostic technique to overcome misdiagnosis and treat asymptomatic carriers is of note. This study aimed to identify new B. bacilliformis antigenic candidates that could lead to a new diagnostic tool able to be implemented in endemic rural areas. METHODOLOGY/PRINCIPAL FINDINGS: Blood (n = 198) and serum (n = 177) samples were collected in northern Peru. Clinical data were recorded. Specific 16S rRNA amplification by RT-PCR, IFA and ELISA for IgM/IgG with whole cells as antigens was done. Western blot analysis and N-terminal amino acid sequencing detected seroreactive proteins. ELISAs for IgM/IgG for the antigenic candidates were performed. Of the population 33.3% reported at least one symptom compatible with Carrion's disease; 25.4% (IFA), 27.1% (ELISA-IgG), 33.9% (ELISA-IgM) and 38.9% (RT-PCR) of samples were positive. Four proteins were considered potential antigenic candidates, including two new antigenic candidates, succinyl-CoA synthetase subunit alpha (SCS-alpha) and succinyl-CoA synthetase subunit beta (SCS-beta). On Western blot both Pap31 and SCS-alpha interacted with IgM, while GroEL and SCS-beta interacted with IgG. The presence of specific antibodies against the antigenic candidates varied from 34.5% (IgG against SCS-alpha) to 97.2% (IgM against Pap31). CONCLUSIONS/SIGNIFICANCE: RT-PCR and the high levels of positivity for specific ELISAs demonstrate high levels of B. bacilliformis exposure and asymptomatic carriers among inhabitants. The new antigens identified might be used as a new rapid diagnostic tool to diagnose acute Carrion's disease and identify asymptomatic carriers

Cytoadhesion to gC1qR through Plasmodium falciparum Erythrocyte Membrane Protein 1 in Severe Malaria

Cytoadhesion of Plasmodium falciparum infected erythrocytes to gC1qR has been associated with severe malaria, but the parasite ligand involved is currently unknown. To assess if binding to gC1qR is mediated through the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family, we analyzed by static binding assays and qPCR the cytoadhesion and var gene transcriptional profile of 86 P. falciparum isolates from Mozambican children with severe and uncomplicated malaria, as well as of a P. falciparum 3D7 line selected for binding to gC1qR (Pf3D7gC1qR). Transcript levels of DC8 correlated positively with cytoadhesion to gC1qR (rho = 0.287, P = 0.007), were higher in isolates from children with severe anemia than with uncomplicated malaria, as well as in isolates from Europeans presenting a first episode of malaria (n = 21) than Mozambican adults (n = 25), and were associated with an increased IgG recognition of infected erythrocytes by flow cytometry. Pf3D7gC1qR overexpressed the DC8 type PFD0020c (5.3-fold transcript levels relative to Seryl-tRNA-synthetase gene) compared to the unselected line (0.001-fold). DBLbeta12 from PFD0020c bound to gC1qR in ELISA-based binding assays and polyclonal antibodies against this domain were able to inhibit binding to gC1qR of Pf3D7gC1qR and four Mozambican P. falciparum isolates by 50%. Our results show that DC8-type PfEMP1s mediate binding to gC1qR through conserved surface epitopes in DBLbeta12 domain which can be inhibited by strain-transcending functional antibodies. This study supports a key role for gC1qR in malaria-associated endovascular pathogenesis and suggests the feasibility of designing interventions against severe malaria targeting this specific interaction

DETECCIÓN DE Lophomonas blattarum EN MUESTRAS DE ESPUTO TEÑIDAS CON AZUL DE METILENO DE INDIVIDUOS ADULTOS DE UN ÁREA URBANA DE LA PROVINCIA DE CHIRIQUÍ.

Lophomonas is a genus of multi-flagellated protozoans consisting in two species Lophomonas striata and Lophomonas blattarum. Both species are considered endocommensal parasites of some domestic pest insects. While L. striata has no importance in public health, L. blattarum is the causal agent of lophomoniasis, a respiratory tract parasitic infection that mostly affect children and immunocompromised adults. A previous study from our group, reported an important prevalence of L. blattarum in the intestinal tract of American cockroaches (Periplaneta americana), collected in the peridomiciliary zone of houses from an urban area of Panamá. Based on this, we aimed to screen by Methylene Blue-staining the sputum samples from immunocompetent adults (N=80) with bronchopulmonary affections to detect potential carriers of L. blattarum. A total of 53 individuals were included in the analysis. We observed the presence of L. blattarum in 19 out of 53 wet Methylene blue-stained samples. Our results point out a substantial prevalence (35.8%) of L. blattarum positive individuals in an area with high incidence of respiratory problems. In addition, we propose the use of Methylene blue stain as a quick and economic diagnostic tool; this reagent highlights the morphological structures of the parasite making easy its identification.Lophomonas es un género de protozoos flagelados que contiene dos especies, Lophomonas striata y L. blattarum. Ambas son consideras endocomensales parásitos de insectos domésticos. Aunque L. striata no se considera importante en salud pública, L. blattarum es el agente causal de una infección respiratoria llamada lofomoniasis que afecta a niños y a adultos inmunosuprimidos. Un estudio previo, reportó importante prevalencia de L. blattraum en el tracto intestinal de especímenes de Periplaneta americana colectados en el peridomicilio de zonas urbanas de la República de Panamá. Analizamos mediante tinción con azul de metileno muestras de esputos de adultos que presentaban afecciones broncorespiratorias con el objetivo de detectar la presencia de L. blattarum en potenciales portadores. Se analizaron 53 muestras y se observó la presencia de L. blattarum en 19 muestras teñidas con azul de metileno. Nuestros hallazgos señalan una importante prevalencia (35.8%) de L. blattarum en muestras de esputo de individuos que viven en una zona con alta incidencia de problemas respiratorios. Estos resultados basados en tinción con azul de metileno, destacan la utilización de esta técnica rápida y económica como metodología diagnóstica. Este reactivo resalta las estructuras morfológicas del parásito haciendo fácil su identificación y diagnóstico en muestras de esputo

Succinil-CoA sintetasa: Nueva antígeno candidato de Bartonella bacilliformis

El estudio fue apoyado por el Programa Nacional de Innovación para la Competitividad y Productividad (Innovar Perú).FONDO: Bartonella bacilliformis es el agente causante de la enfermedad de Carrion, una enfermedad descuidado con tasas de mortalidad de 40 a 85% en ausencia de tratamiento. La falta de una técnica de diagnóstico para superar un mal diagnóstico y el tratamiento de portadores asintomáticos es de nota. Este estudio tuvo como objetivo identificar nuevos candidatos B. bacilliformis antigénicos que podrían dar lugar a una nueva herramienta de diagnóstico capaz de ser implementado en las zonas rurales endémicas

Succinil-CoA sintetasa: Nueva antígeno candidato de Bartonella bacilliformis

El estudio fue apoyado por el Programa Nacional de Innovación para la Competitividad y Productividad (Innovar Perú).FONDO: Bartonella bacilliformis es el agente causante de la enfermedad de Carrion, una enfermedad descuidado con tasas de mortalidad de 40 a 85% en ausencia de tratamiento. La falta de una técnica de diagnóstico para superar un mal diagnóstico y el tratamiento de portadores asintomáticos es de nota. Este estudio tuvo como objetivo identificar nuevos candidatos B. bacilliformis antigénicos que podrían dar lugar a una nueva herramienta de diagnóstico capaz de ser implementado en las zonas rurales endémicas

Succinyl-CoA Synthetase: New Antigen Candidate of Bartonella bacilliformis

BACKGROUND: Bartonella bacilliformis is the causative agent of Carrion's disease, a neglected illness with mortality rates of 40-85% in the absence of treatment. The lack of a diagnostic technique to overcome misdiagnosis and treat asymptomatic carriers is of note. This study aimed to identify new B. bacilliformis antigenic candidates that could lead to a new diagnostic tool able to be implemented in endemic rural areas. METHODOLOGY/PRINCIPAL FINDINGS: Blood (n = 198) and serum (n = 177) samples were collected in northern Peru. Clinical data were recorded. Specific 16S rRNA amplification by RT-PCR, IFA and ELISA for IgM/IgG with whole cells as antigens was done. Western blot analysis and N-terminal amino acid sequencing detected seroreactive proteins. ELISAs for IgM/IgG for the antigenic candidates were performed. Of the population 33.3% reported at least one symptom compatible with Carrion's disease; 25.4% (IFA), 27.1% (ELISA-IgG), 33.9% (ELISA-IgM) and 38.9% (RT-PCR) of samples were positive. Four proteins were considered potential antigenic candidates, including two new antigenic candidates, succinyl-CoA synthetase subunit alpha (SCS-alpha) and succinyl-CoA synthetase subunit beta (SCS-beta). On Western blot both Pap31 and SCS-alpha interacted with IgM, while GroEL and SCS-beta interacted with IgG. The presence of specific antibodies against the antigenic candidates varied from 34.5% (IgG against SCS-alpha) to 97.2% (IgM against Pap31). CONCLUSIONS/SIGNIFICANCE: RT-PCR and the high levels of positivity for specific ELISAs demonstrate high levels of B. bacilliformis exposure and asymptomatic carriers among inhabitants. The new antigens identified might be used as a new rapid diagnostic tool to diagnose acute Carrion's disease and identify asymptomatic carriers

Positive prevalence for the antigenic candidate ELISAs.

<p>Positive prevalence for the antigenic candidate ELISAs.</p

Example of a positive IFA test.

<p>A) 20X objective and 10X oculars. B) 100X objective and 10X oculars.</p

Antigenic candidates of <i>B</i>. <i>bacilliformis</i> selected.

<p>A) SDS gel with sonicated whole cell <i>B</i>. <i>bacilliformis</i>. B) Example of a Western blot with a positive serum by ELISA. The left panel corresponds to IgG and the right panel to IgM.</p

Distribution of the positive individuals for each diagnostic technique used according to the symptoms described.

<p>Distribution of the positive individuals for each diagnostic technique used according to the symptoms described.</p