Ana Cláudia Calchi

Dr. Ana Cláudia Calchi


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

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

Representative Publications

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14 March 2022 in Microorganisms
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AMAnna Mongruel
Anna Mongruel
EMEmília Patrícia Medici
Emília Patrícia Medici
ACAriel da Costa Canena
Ariel da Costa Canena
ACAna Cláudia Calchi
Ana Cláudia Calchi
RMRosangela Machado
Rosangela Machado
MAMarcos André
Marcos André
The lowland tapir (Tapirus terrestris) is the largest land mammal in Brazil and classified as a vulnerable species, according to the assessment of the risk of extinction. The present study aimed at investigating the occurrence and genetic diversity of hemoplasmas in free-ranging T. terrestris from the Brazilian Pantanal and Cerrado biomes. Blood samples were collected from 94 living and eight road-killed tapirs, totalizing 125 samples Conventional PCR targeting four different genes (16S rRNA, 23S rRNA, RNAse P, and dnaK) were performed, and the obtained sequences were submitted for phylogenetic, genotype diversity, and distance analyses. The association between hemoplasma positivity and possible risk variables (age, gender, and origin) was assessed. Out of 122 analyzed samples, 41 (41/122; 33.61% CI: 25.84–42.38%) were positive in the 16S rRNA-based PCR assay for hemoplasmas. Positivity for hemoplasmas did not differ between tapirs’ gender and age. Tapirs from Pantanal were 5.64 times more likely to present positive results for hemoplasmas when compared to tapirs sampled in Cerrado. BLASTn, phylogenetic, genotype diversity, and distance analyses performed herein showed that the sampled lowland tapirs might be infected by two genetically distinct hemoplasmas, namely ‘Candidatus Mycoplasma haematoterrestris’ and ‘Candidatus Mycoplasma haematotapirus’. While the former was positioned into “Mycoplasma haemofelis group” and closely related to ‘Candidatus Mycoplasma haematoparvum, the latter was positioned into “Mycoplasma suis group” and closely related to ‘Candidatus Mycoplasma haematobos’. The impact of both putative novel species on tapir health status should be investigated.

16 January 2022 in Pathogens
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MAMarcos André
Marcos André
ACAna Cláudia Calchi
Ana Cláudia Calchi
MFMaria Eduarda Furquim
Maria Eduarda Furquim
IAIsabela de Andrade
Isabela de Andrade
PAPaulo Vitor Cadina Arantes
Paulo Vitor Cadina Arantes
RMRosangela Machado
Rosangela Machado
Even though the epidemiology of tick-borne agents (TBA) in dogs has been extensively investigated around the world, the occurrence, vectors involved, and molecular identity of these agents in cats remains elusive in many regions. Among TBA, Ehrlichia, Anaplasma, Babesia, Cytauxzoon, and Hepatozoon are responsible for diseases with non-specific clinical signs in cats, making essential the use of molecular techniques for accurate diagnosis and proper treatment. The present work aimed to investigate the occurrence and molecular identity of tick-borne agents (Ehrlichia, Anaplasma, Babesia/Theileria, Cytauxzoon, and Hepatozoon) in cats from southeastern (states of São Paulo (SP) and Minas Gerais (MG)) and northern (state of Rondônia (RO)) Brazil. For this purpose, 390 blood samples were collected from domiciled cats in MG (n = 155), SP (n = 151), and RO(n = 84) states, submitted to DNA extraction and PCR assays for Ehrlichia spp. (dsb gene), Anaplasma spp. (rrs gene), piroplasmids (18S rRNA gene), and Hepatozoon spp. (18S rRNA gene), sequencing, and phylogenetic inferences. The overall positivity for Anaplasma spp., Ehrlichia spp., Babesia/Theileria spp., Cytauxzoon spp., and Hepatozoon spp. were 7.4% (12.3% (MG) and 6.6% (SP)), 2% (4.5% (MG) and 0.6% (SP)), 0.7% (0.6% (MG), 0.6% (SP) and 1.2% (RO)), 27.2% (41.9% (MG), 24.5% (SP) and 4.8% (RO), and 0%, respectively. The phylogenetic analysis grouped the obtained sequences with ‘Candidatus Anaplasma amazonensis’, A. platys, B. vogeli, and Cytauxzoon sp. previously detected in wild felids from Brazil. qPCR specific for E. canis based on the dsb gene confirmed the molecular identity of the detected ehrlichial agent. The present study expanded the list and geographical distribution of hemoparasites in cats. ‘Candidatus Anaplasma amazonensis’, recently detected in sloths from northern Brazil, was described for the first time in cats. This is the first report of piroplasmids infecting cats in northern Brazil. Coinfection by Cytauxzoon and other TBA (Ehrlichia, Anaplasma, and B. vogeli) reported in the present study raises the need for veterinary practitioners’ awareness of cats parasitized by multiple TBA.

23 November 2022 in Microorganisms
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Journal Article
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AMAnna Mongruel
Anna Mongruel
EMEmília Patrícia Medici
Emília Patrícia Medici
ACAriel da Costa Canena
Ariel da Costa Canena
ACAna Cláudia Calchi
Ana Cláudia Calchi
LPLívia Perles
Lívia Perles
MAMarcos André
Marcos André
The low-land tapir (Tapirus terrestris) is the largest wild terrestrial mammal found in Brazil. Although T. terrestris has been already reported as a host of hemoparasites, the occurrence and genetic identity of Piroplasmida agents in this species is still cloudy. Although it is reported that Theileria equi, an endemic equid-infective agent in Brazil, is occurring in lowland tapirs, these reports are probably misconceived diagnoses since they are solely based on small fragments of 18S rRNA that may not achieve accurate topologies on phylogenetic analyses. The present study aimed to detect and investigate the identity of Theileria spp. in tapirs from Pantanal and Cerrado biomes. Blood-DNA samples from tapirs were screened for a partial (~800 bp) 18S rRNA gene fragment from Piroplasmida and 64 (64/122; 52.46% CI: 43.66–61.11%) presented bands of expected size. Samples were submitted to different protocols for molecular characterization, including near-full length 18S rRNA gene (~1500 bp), and the ema-1 gene from T. equi. Eight sequences were obtained for extended fragments (1182–1473 bp) from the 18S rRNA gene. Moreover, three sequences from partial cox-1 and five from partial hsp70 gene were obtained. None of the samples presented amplifications for the ema-1 gene. Phylogenetic and distance analyses from the 18S rRNA sequences obtained demonstrated a clear separation from tapirs’ Theileria spp. and T. equi. Phylogenetic analyses of cox-1 and hsp70 sequences obtained herein also showed a unique clade formed by tapir’s Theileria spp. Theileria terrestris sp. nov. is positioned apart from all other Theileria species in 18S rRNA, cox-1, and hps70 phylogenetic analyses. This novel proposed species represents a new Piroplasmida clade, yet to be characterized regarding biological features, vectors involved in the transmission cycles, additional vertebrate hosts, and pathogenicity.

30 November 2022 in Microorganisms
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LPLívia Perles
Lívia Perles
HHHeitor Herrera
Heitor Herrera
WBWanessa T. G. Barreto
Wanessa T. G. Barreto
GMGabriel Macedo
Gabriel Macedo
ACAna Cláudia Calchi
Ana Cláudia Calchi
MAMarcos André
Marcos André
The Anaplasmataceae family encompasses obligate intracellular α-proteobacteria of human and veterinary medicine importance. This study performed multi-locus sequencing to characterize Ehrlichia and Anaplasma in coati’s blood samples in Midwestern Brazil. Twenty-five samples (25/165—15.1%) were positive in the screening PCR based on the dsb gene of Ehrlichia spp. and were characterized using 16S rRNA, sodB, groEL, and gltA genes and the 23S-5S intergenic space region (ITS). Phylogenetic analyses based on all six molecular markers positioned the sequences into a new clade, with a common origin of Ehrlichia ruminantium. Haplotype analyses of 16S RNA sequences revealed the presence of two distinct Ehrlichia genotypes. Six samples (6/165, 3.6%) were positive in the screening nPCR for the 16S rRNA gene of Anaplasma spp. and were submitted to an additional PCR targeting the ITS for molecular characterization. Phylogenetic analyses based on both 16S rRNA gene and ITS positioned the Anaplasma sp. detected in the present study in a large clade with other Anaplasma sp. previously detected in ticks and wild animals and in a clade with ‘Candidatus Anaplasma brasiliensis’, respectively. Based on distinct molecular markers, the present work described a putative novel Anaplasmataceae agent, namely ‘Candidatus Ehrlichia dumleri’, and Anaplasma sp. closely related to the previously described ‘Candidatus Anaplasma brasiliensis’.

11 December 2024 in Pathogens
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ACAna Cláudia Calchi
Ana Cláudia Calchi
CMCharlotte Moore
Charlotte Moore
LBLillianne Rae Bartone
Lillianne Rae Bartone
EKEmily Marie Kingston
Emily Marie Kingston
MAMarcos André
Marcos André
RMRicardo G Maggi
Ricardo G Maggi
More than one-hundred Babesia species that affect animals and humans have been described, eight of which have been associated with emerging and underdiagnosed zoonoses. Most diagnostic studies in humans have used serology or molecular assays based on the 18S rRNA gene. Because the 18S rRNA gene is highly conserved, obtaining an accurate diagnosis at the species level is difficult, particularly when the amplified DNA fragment is small. Also, due to its low copy number, sequencing of the product is often unsuccessful. In contrast, because the Babesia internal transcribed regions (ITS), between 18S rRNA and 5.8S rRNA, and between 5.8S rRNA and 28S rRNA, contain highly variable non-coding regions, the sequences in these regions provide a good option for developing molecular assays that facilitate differentiation at the species level. In this study, the complete ITS1 and ITS2 intergenic regions of different Piroplasmida species were sequenced to add to the existing GenBank database. Subsequently, ITS1 and ITS2 sequences were used to develop species-specific PCR assays and specific single-plex and multiplex conventional (c)PCR, quantitative real-time (q)PCR, and digital (d)PCR assays for four zoonotic Babesia species (Babesia divergens, Babesia odocoilei, Babesia duncani, and Babesia microti). The efficacy of the assay protocols was confirmed by testing DNA samples extracted from human blood or enrichment blood cultures. Primers were first designed based on the 18S rRNA-5.8S rRNA and 5.8S rRNA-28S rRNA regions to obtain the ITS1 and ITS2 sequences derived from different Piroplasmida species (B. odocoilei, Babesia vulpes, Babesia canis, Babesia vogeli, Babesia gibsoni, Babesia lengau, Babesia divergens-like, B. duncani, B. microti, Babesia capreoli, Babesia negevi, Babesia conradae, Theileria bicornis, and Cytauxzoon felis). Subsequently, using these sequences, single-plex or multiplex protocols were optimized targeting the ITS1 region of B. divergens, B. microti, and B. odocoilei. Each protocol proved to be sensitive and specific for the four targeted Babesia sp., detecting 10−2 (for B. microti and B. odocoilei) and 10−1 (for B. divergens and B. duncani) DNA copies per microliter. There was no cross-amplification among the Babesia species tested. Using 226 DNA extractions from blood or enrichment blood cultures obtained from 82 humans, B. divergens (seven individuals), B. odocoilei (seven individuals), and B. microti (two individuals) were detected and identified as a single infection, whereas co-infection with more than one Babesia sp. was documented by DNA sequencing in six (7.3%) additional individuals (representing a 26.8% overall prevalence). These newly developed protocols proved to be effective in detecting DNA of four Babesia species and facilitated documentation of co-infection with more than one Babesia sp. in the same individual.

6 August 2023 in Microorganisms
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FKFelipe Krawczak
Felipe Krawczak
ACAna Cláudia Calchi
Ana Cláudia Calchi
LNLucianne Cardoso Neves
Lucianne Cardoso Neves
SDSarah Alves Dias
Sarah Alves Dias
BSBianca Fonseca da Silva
Bianca Fonseca da Silva
MAMarcos André
Marcos André
Piroplasmids (order Piroplasmida) are a diverse group of tick-borne protozoa that may cause disease in animals and occasionally in humans. Novel Piroplasmida clades and species have been found in wild animals from Brazil based on the phylogenetic assessment of near-complete 18S rRNA, mitochondrial and heat-shock protein genes. For instance, a putative novel Babesia species has been detected in capybaras and Amblyomma ticks in three Brazilian states. The present work aimed to describe, using phylogenetic assessments based on distinct molecular markers, this novel Babesia species in capybaras and associated ticks (Amblyomma sculptum and Amblyomma dubitatum) sampled in Goiânia city, Goiás state, midwestern Brazil. While the phylogenetic analysis based on both near-complete 18S rRNA and hsp-70 genes positioned the sequences obtained from capybara blood samples into a new clade sister to the Babesia sensu stricto clade, the phylogenetic inference based on the COX-3 amino acid positioned the obtained sequences from capybara blood samples and A. sculptum ticks also into a clade sister to the Theileria sensu stricto clade, highlighting the inappropriateness of this marker inferring evolutionary relationships among piroplasmids. Pairwise distance analysis demonstrated that the divergence rates between the 18S rRNA sequences detected in capybaras and other Piroplasmida already described were very high and ranged from 9.4 to 12.9%. Genotype analysis based on the near-full 18S rRNA sequences of the Piroplasmida detected in capybaras and associated ticks demonstrated the occurrence of high genotype diversity at an intra-species level. In conclusion, phylogenetic analyses based on distinct molecular markers supported the description of Babesia goianiaensis nov. sp. in capybaras and associated Amblyomma ticks. Additionally, a novel phylogenetic clade, apart from the previously described ones, was described in the present study and contributed to untangling the complex evolutionary history of the Piroplasmida.