Zara Assis-Silva

Mrs. Zara Assis-Silva


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 July 2023 in Veterinary Sciences
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Journal Article
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JSJuliana Bruno Borges Souza
Juliana Bruno Borges Souza
ZAZara Assis-Silva
Zara Assis-Silva
BABruna Samara Alves-Ribeiro
Bruna Samara Alves-Ribeiro
IMIago de Sá Moraes
Iago de Sá Moraes
AAAna Vitória Alves-Sobrinho
Ana Vitória Alves-Sobrinho
Dirceu Guilherme de Souza RamosDirceu Guilherme de Souza Ramos
Dirceu Guilherme de Souza Ramos
Gastrointestinal diseases caused by parasites are frequently diagnosed in the clinical routine of domestic animals, especially dogs and cats. In general, they trigger factors that can affect human health due to zoonoses. Therefore, this study aims to identify the main intestinal parasites obtained from the fecal samples of dogs and cats in the municipality of Jata, Brazil, and their associated risk factors. Between October 2020 and March 2022, fecal samples were collected from 359 dogs and 55 cats through spontaneous defecation and subsequently subjected to coproparasitological analyses using the Willis fluctuation and Hoffman spontaneous sedimentation techniques. The following parasitic species were identified: Ancylostoma spp., Toxocara spp., Trichuris vulpis, Dipylidium caninum; Giardia spp., Entamoeba spp., Cystoisospora spp., and Platynosomum fastosum. The risk factors associated with parasitism include age, average income of owners, access to garbage, sewage, waste, outdated deworming, and contact with animals. The results demonstrate the need to establish public policies and implement preventive and control measures to reduce the occurrence of parasites in animals and the exposure of humans to pathogenic agents

5 December 2024 in Veterinary Sciences
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Journal Article
Open access
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BABruna Samara Alves-Ribeiro
Bruna Samara Alves-Ribeiro
RDRaiany Borges Duarte Raiany Borges Duarte
Raiany Borges Duarte Raiany Borges Duarte
ZAZara Assis-Silva
Zara Assis-Silva
AGAna Paula Carvalho Gomes
Ana Paula Carvalho Gomes
YSYasodaja Assis Silva
Yasodaja Assis Silva
ÍBÍsis Assis Braga
Ísis Assis Braga
Canine monocytic ehrlichiosis (CME) is an infectious disease caused by Ehrlichia canis, a globally recognized obligate intracellular bacterium. In addition to dogs, other animals, including humans, may be affected. Despite its epidemiological importance and impact on public health, there is currently no commercial vaccine against E. canis. This study aimed to present relevant aspects of the challenges and advances encountered in the development of vaccines for CME and highlight perspectives for future investigations. High genetic variability, along with the various evasion mechanisms employed by E. canis, has hindered the identification of an antigen that targets Th1 cells and is immunogenic to most E. canis isolates, considering their genotypic and phenotypic characteristics. The vaccine must predominantly confer cellular and humoral immunity to achieve robust immune responses. Early production efforts have been challenging due to low immunogenicity, difficulties in establishing long-term protection, and limitations of the techniques used. However, with the refinement of bioinformatic tools, research in this area will be facilitated, thereby accelerating the development of effective vaccines for CME. According to these authors, this vaccine should consist of multiple epitopes.

30 May 2024 in Animals
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Journal Article
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IMIago de Sá Moraes
Iago de Sá Moraes
VSVictória Luiza de Barros Silva
Victória Luiza de Barros Silva
BSBeatriz Elise Andrade Silva
Beatriz Elise Andrade Silva
AGAna Paula Gomes
Ana Paula Gomes
NUNicoly Ferreira de Urzedo
Nicoly Ferreira de Urzedo
Dirceu Guilherme de Souza RamosDirceu Guilherme de Souza Ramos
Dirceu Guilherme de Souza Ramos
Environmental changes in the Brazilian Pantanal and Cerrado facilitate the spread of parasitic diseases in wildlife, with significant implications for public health owing to their zoonotic potential. This study aimed to examine the occurrence and diversity of gastrointestinal parasites in wild felids within these regions to assess their ecological and health impacts. We collected and analyzed helminth-positive samples from 27 wild felids using specific taxonomic keys. Diverse parasitic taxa were detected, including zoonotic helminths, such as Ancylostoma braziliense, Ancylostoma caninum, Ancylostoma pluridentatum, Toxocara cati, Toxocara canis, Dipylidium caninum, Taenia spp., Echinococcus spp., and Spirometra spp. Other nematodes, such as Physaloptera praeputialis and Physaloptera anomala, were identified, along with acanthocephalans from the genus Oncicola and a trematode, Neodiplostomum spp. (potentially the first record of this parasite in wild felids in the Americas). Human encroachment into natural habitats has profound effects on wild populations, influencing parasitic infection rates and patterns. This study underscores the importance of continuous monitoring and research on parasitic infections as a means of safeguarding both wildlife and human populations and highlights the role of wild felids as bioindicators of environmental health.

21 February 2025 in Pathogens
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Journal Article
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AMAna Julia De Almeida Martins
Ana Julia De Almeida Martins
ARAlice Silva Rocha
Alice Silva Rocha
ZAZara Assis-Silva
Zara Assis-Silva
GMGuilherme Oliveira Maia
Guilherme Oliveira Maia
BABruna Samara Alves-Ribeiro
Bruna Samara Alves-Ribeiro
ÍBÍsis Assis Braga
Ísis Assis Braga
The risk of zoonotic parasitic infections is closely linked to direct and indirect interactions between animals and humans. The mutual coexistence of species in public spaces predisposes individuals to gastrointestinal parasitosis owing to various social and hygienic-sanitary factors. This study aimed to assess the risk of environmental contamination by gastrointestinal parasites in fecal samples collected from parks and public squares in 18 municipalities located in a microregion of the central plateau of Brazil, correlating the collection with the population size of each municipality. We collected 536 soil fecal samples from 117 randomly selected public areas across a 56,111.874 km2 region. Eggs, cysts, and oocysts were detected using the Willis flotation technique and the Hoffman’s spontaneous sedimentation method. The Hoffman’s analysis revealed that 70.3% of the fecal samples were infected across 91.5% of the sampled areas. Identified parasites included the members of the family Ancylostomatidae (56.5%), Toxocara spp. (6.2%), Trichuris spp. (1.7%), Strongyloides spp. (0.2%), Dipylidium caninum (25.8%), Spirometra spp. (0.4%), Taeniidae (0.2%), Platynosomum fastosum (0.6%), Trematoda (0.2%), Giardia spp. (3.2%), Cystoisospora spp. (5.6%), Sarcocystis spp. (0.2%), and Entamoeba spp. (2.4%). The presence of positive fecal samples in public areas and municipalities correlated with populations of up to 10,000 inhabitants (p = 0.023). Areas contaminated with feces were 63.4% more likely to contain parasites than other areas (odds ratio 1.6336). Favorable environmental factors combined with inadequate sanitary management contribute to a high risk of environmental contamination, representing a significant zoonotic potential and highlighting the need for improved public health policies and preventive measures.

29 October 2024 in Preprints.org
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Preprint
Open access
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BABruna Samara Alves-Ribeiro
Bruna Samara Alves-Ribeiro
RDRaiany Borges Duarte
Raiany Borges Duarte
ZAZara Assis-Silva
Zara Assis-Silva
AGAna Paula Carvalho Gomes
Ana Paula Carvalho Gomes
YSYasodaja Assis Silva
Yasodaja Assis Silva
ÍBÍsis Assis Braga
Ísis Assis Braga
Canine monocytic ehrlichiosis (CME) is an infectious disease caused by Ehrlichia canis, a globally recognized obligate intracellular bacterium. In addition to dogs, other animals, including humans, may be affected. Despite its epidemiological importance and impact on public health, there is currently no commercial vaccine against E. canis. This study aimed to present relevant aspects of the challenges and advances encountered in the development of vaccines for CME and highlight perspectives for future investigations. High genetic variability, along with the various evasion mechanisms employed by E. canis, has hindered the identification of an antigen that targets Th1 cells and is immunogenic to most E. canis isolates, considering their distinct antigenic characteristics. To achieve robust immunity, the vaccine must predominantly confer cellular and humoral immunity. Early production efforts have been challenging owing to low immunogenicity, difficulties in establishing long-term protection, and limitations of the techniques used. However, with the refinement of bioinformatic tools, research in this area will be facilitated, thereby accelerating the development of effective vaccines for CME. According to these authors, a vaccine should consist of multiple epitopes.

6 June 2025 in Preprints.org
Verified
Preprint
Open access
PDF file
LZLetícia Caetano Zaiden
Letícia Caetano Zaiden
LFLizandra Fernandes-Silva
Lizandra Fernandes-Silva
ZAZara Assis-Silva
Zara Assis-Silva
NUNicoly Ferreira de Urzedo
Nicoly Ferreira de Urzedo
VSVictória Luiza de Barros Silva
Victória Luiza de Barros Silva
Dirceu Guilherme de Souza RamosDirceu Guilherme de Souza Ramos
Dirceu Guilherme de Souza Ramos
Brazil has a high abundance of monkey species, including Mico melanurus. In general, primates are vulnerable to parasites owing to their behavior. We aimed to identify the occurrence of gastrointestinal parasites in M. melanurus in the Brazilian Cerrado and to perform morphometric and morphological analyses of these helminths. Helminths of 21 M. melanurus were collected from Cuiabá in the Brazilian Cerrado. The animals were found dead within the urban perimeter, necropsied, and tested for parasites. Parasites found in the gastrointestinal tract were fixed in 70% ethanol for morphological identification. We identified Trypanoxyuris spp. in two samples (mean intensity of 63 and mean abundance of 6.3) and Primasubulura jacchi in the other 18 samples (mean intensity of 34.22 and mean abundance of 30.8). One sample was deteriorated; therefore, it was not necropsied. P. jacchi infections in same cases are asymptomatic or have gastrointestinal signs such as diarrhea. Trypanoxyuris spp. are commonly found in the primates of Mato Grosso. Only these two parasites were identified, provided by a small parasite richness, and were associated with the impact of habitat fragmentation in an anthropized area, indicating an imbalance in the environment in which they lived.