Incidence of human and free-ranging wild rodent infections with Leishmania (Viannia) braziliensis, aetiological agent of cutaneous Leishmaniasis

Background. Human and wild rodent infection rates with Leishmania (Viannia) braziliensis are needed to differentiate transmission pathways in anthropogenically altered habitats. Methods. Human participants in northeast Brazil were tested by the leishmanin skin test (LST) and inspected for lesions/scars characteristic of American clinical leishmaniasis (ACL). Molecular (PCR/qPCR) test records of free-ranging rodents were available from a concurrent capture–mark–recapture study. Force of Infection (λ) and recovery (ρ) rates were estimated from cross-sectional and longitudinal datasets. Results. Cumulative prevalences of human LST+ves and ACL scar+ves were 0.343–0.563 (n = 503 participants) and 0.122–0.475 (n = 503), respectively. Active ACL lesions were not detected. Annual rates of LST conversions were λ = 0.03–0.15 and ρ = 0.02–0.07. The probability of infection was independent of sex and associated with increasing age in addition to the period of exposure. Rodents (n = 596 individuals of 6 species) showed high rates of exclusively asymptomatic infection (λ = 0.222/month) and potential infectiousness to the sand fly vector. Spatially concurrent rodent and household human infection prevalences were correlated. Conclusions. Human exposure to L. (V.) braziliensis continues to be high despite the substantial drop in reported ACL cases in recent years. Spill-over transmission risk to humans from rodents in peridomestic habitats is likely supported by a rodent infection/transmission corridor linking houses, plantations, and the Atlantic Forest

The compositional landscape of minicircle sequences isolated from active lesions and scars of American cutaneous leishmaniasis

Submitted by sandra infurna ([email protected]) on 2016-07-14T15:41:26Z No. of bitstreams: 1 octavio_fernandes_etal_IOC_2013.pdf: 998508 bytes, checksum: e842184f76aed4b07fa8930601e0bbe3 (MD5)Approved for entry into archive by sandra infurna ([email protected]) on 2016-07-14T15:51:04Z (GMT) No. of bitstreams: 1 octavio_fernandes_etal_IOC_2013.pdf: 998508 bytes, checksum: e842184f76aed4b07fa8930601e0bbe3 (MD5)Made available in DSpace on 2016-07-14T15:51:04Z (GMT). No. of bitstreams: 1 octavio_fernandes_etal_IOC_2013.pdf: 998508 bytes, checksum: e842184f76aed4b07fa8930601e0bbe3 (MD5) Previous issue date: 2013Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Departamento de Imunologia. Laboratório de Imunopatalogia e Biologia Molecular. Recife, PE, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Departamento de Imunologia. Laboratório de Imunopatalogia e Biologia Molecular. Recife, PE, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Departamento de Imunologia. Laboratório de Imunopatalogia e Biologia Molecular. Recife, PE, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Departamento de Imunologia. Laboratório de Imunopatalogia e Biologia Molecular. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório Interdisciplinar de Pesquisas Médicas. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Departamento de Imunologia. Laboratório de Imunopatalogia e Biologia Molecular. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório Interdisciplinar de Pesquisas Médicas. Rio de Janeiro, RJ, Brasil.American cutaneous leishmaniasis (ACL) is characterized by cutaneous lesions that heal spontaneously or after specific treatment. This paper reports on the analysis of kDNA minicircle sequences from clinical samples (typical lesions and scars) that were PCR-amplified with specific primers for Leishmania species of the subgenus Viannia

Design, Construction, and Evaluation of a Specific Chimeric Antigen To Diagnose Chagasic Infection

Chagas' disease is routinely diagnosed by detecting specific antibodies (Abs) using serological methods. The methodology has the drawback of potential cross-reactions with Abs raised during other infectious and autoimmune diseases (AID). Fusion of DNA sequences encoding antigenic proteins is a versatile tool to engineer proteins to be used as sensitizing elements in serological tests. A synthetic gene encoding a chimeric protein containing the C-terminal region of C29 and the N-terminal region of TcP2β was constructed. A 236-serum panel, composed of 104 reactive and 132 nonreactive sera to Chagas' disease, was used to evaluate the performance of the chimera. Among the nonreactive sera, 65 were from patients with AID (systemic lupus erythematosus and rheumatoid arthritis) or patients infected with Leishmania brasiliensis, Brucella abortus, Streptococcus pyogenes, or Toxoplasma gondii. The diagnostic performances of the complete TcP2β (TcP2β(FL)) and its N-terminal region (TcP2β(N)) were evaluated. TcP2β(FL) showed unspecific recognition toward leishmaniasis (40%) and AID Abs (58%), while TcP2β(N) showed no unspecific recognition. The diagnostic utility of the chimera was evaluated by analyzing reactivity and comparing the results with those obtained with TcP2β(N). The chimera reactivity was higher than that of the peptide fractions (0.874 versus 0.564 optical density, P = 0.0017). The detectability and specificity were both 100% for the whole serum panel tested. We conclude that the obtained chimera shows an improved selectivity and sensitivity compared with other ones previously reported, therefore displaying an optimized performance for Trypanosoma cruzi infection diagnosis

Identification of divergent Leishmania (Viannia) braziliensis ecotypes derived from a geographically restricted area through whole genome analysis.

Leishmania braziliensis, the main etiological agent of cutaneous leishmaniasis (CL) in Latin America, is characterized by major differences in basic biology in comparison with better-known Leishmania species. It is also associated with a high phenotypic and possibly genetic diversity that need to be more adequately defined. Here we used whole genome sequences to evaluate the genetic diversity of ten L. braziliensis isolates from a CL endemic area from Northeastern Brazil, previously classified by Multi Locus Enzyme Electrophoresis (MLEE) into ten distinct zymodemes. These sequences were first mapped using the L. braziliensis M2904 reference genome followed by identification of Single Nucleotide Polymorphisms (SNPs). A substantial level of diversity was observed when compared with the reference genome, with SNP counts ranging from ~95,000 to ~131,000 for the different isolates. When the genome data was used to infer relationship between isolates, those belonging to zymodemes Z72/Z75, recovered from forested environments, were found to cluster separately from the others, generally associated with more urban environments. Among the remaining isolates, those from zymodemes Z74/Z106 were also found to form a separate group. Phylogenetic analyses were also performed using Multi-Locus Sequence Analysis from genes coding for four metabolic enzymes used for MLEE as well as the gene sequence coding for the Hsp70 heat shock protein. All 10 isolates were firmly identified as L. braziliensis, including the zymodeme Z26 isolate previously classified as Leishmania shawi, with the clustering into three groups confirmed. Aneuploidy was also investigated but found in general restricted to chromosome 31, with a single isolate, from zymodeme Z27, characterized by extra copies for other chromosomes. Noteworthy, both Z72 and Z75 isolates are characterized by a much reduced heterozygosity. Our data is consistent with the existence of distinct evolutionary groups in the restricted area sampled and a substantial genetic diversity within L. braziliensis

Use of Full-Length Recombinant Calflagin and Its C Fragment for Improvement of Diagnosis of Trypanosoma cruzi Infection

Serological diagnosis of Trypanosoma cruzi infection is hampered by issues related to test specificity due to the cross-reactivity of most antigens with proteins of related parasites such as Leishmania spp. The recombinant calflagins are considered relevant antigens for the diagnosis of infection by Trypanosoma cruzi. In the present work, we describe two genes coding for putative calflagins in Leishmania major with the N-terminal moieties presenting high similarity with T. cruzi genes. This fact raised questions about their role in some cross-recognition of this antigen by sera from Leishmania spp.-infected individuals. The complete T. cruzi calflagin and two fragments of the protein, consisting of 146 amino acids of the N-terminal and 65 amino acids of the C-terminal regions, were expressed and evaluated against a panel of sera, which included well-characterized samples from T. cruzi, and Leishmania-infected patients. We were able to show that sera from Leishmania (Viannia) braziliensis-infected individuals recognized the recombinant full-length calflagin. Both the N-terminal and the complete protein presented the same high sensitivity (98.5% of sera from T. cruzi-infected patients was detected) but different specificities (94% and 98%, respectively, when evaluated against sera from people not infected by T. cruzi, including 15 sera from people infected with L. braziliensis). The C-terminal fragment presented low sensitivity (70%) but 100% specificity. We propose the use of these antigens in two sequential assays to optimize the serological diagnosis of T. cruzi infection in humans in geographic areas where Leishmania spp. infection is coendemic

Secretory activity and endocrine regulation of male accessory glands in the blood-sucking bug Panstrongylus megistus (Hemiptera: Reduviidae)

The epithelial cells of Panstrongylus megistus male accessory glands (MAG) present ultrastructural characteristics of a secretory cell. Their secretory products are accumulated in the lumen of the four MAG lobes. During the first 8 days of adult life a strong secretion activity occurs, accumulating enough material to produce the first spermatophore. Cerebral neurosecretions as well as juvenile hormone are both involved in MAG secretory activity regulation. Juvenile hormone seems to be the responsible for the stimulation of most protein synthesis in male accessory glands. Cerebral neurosecretion seems to be necessary to stimulate juvenile hormone production and release by the corpus allatum. Furthermore, neurosecretion is required for some polypeptides synthesis by MAG. Although topic application of precocene II to adult males does not reproduce the same effects on MAG as does allatectomy, this compound causes strong reduction on male reproductive capacity

Species diversity of Leishmania (Viannia) parasites circulating in an endemic area for cutaneous leishmaniasis located in the Atlantic rainforest region of northeastern Brazil

OBJECTIVES To identify the aetiological agents of cutaneous leishmaniasis and to investigate the genetic polymorphism of Leishmania (Viannia) parasites circulating in an area with endemic cutaneous leishmaniasis (CL) in the Atlantic rainforest region of northeastern Brazil. METHODS Leishmania spp. isolates came from three sources: (i) patients diagnosed clinically and parasitologically with CL based on primary lesions, secondary lesions, clinical recidiva, mucocutaneous leishmaniasis and scars; (ii) sentinel hamsters, sylvatic or synanthropic small rodents; and (iii) the sand fly species Lutzomyia whitmani. Isolates were characterised using monoclonal antibodies, multilocus enzyme electrophoresis (MLEE) and polymerase chain reaction-restriction fragment length polymorphism of the internal transcribed spacer region rDNA locus. RESULTS Seventy-seven isolates were obtained and characterised. All isolates were identified as Leishmania (Viannia) braziliensis serodeme 1 based on reactivity to monoclonal antibodies. MLEE identified 10 zymodemes circulating in the study region. Most isolates were classified as zymodemes closely related to L. (V.) braziliensis, but five isolates were classified as Leishmania (Viannia) shawi. All but three of the identified zymodemes have so far been observed only in the study region. Enzootic transmission and multiclonal infection were observed. CONCLUSIONS Our results confirm that transmission cycle complexity and the co-existence of two or more species in the same area can affect the level of genetic polymorphism in a natural Leishmania population. Although it is not possible to make inferences as to the modes of genetic exchange, one can speculate that some of the zymodemes specific to the region are hybrids of L. (V.) braziliensis and L. (V.) shawi.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)[410481/2006-8]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco (FACEPE)Fundacao de Amparo a Ciencia e Tecnologia de Pernambuco (FACEPE)Fundacao Oswaldo Cruz[400135/2006-0]Fundação Oswaldo Cruz (Fiocruz)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Fundacao de Amparo a Pesquisa do Rio de Janeiro Carlos Chagas Filho (FAPERJ)European UnionEuropean Union[EU-FP6: INCO-CT2005-015407]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Amparo a Pesquisa de Sao Paulo (FAPESP