| Full text | |
| Author(s): Show less - |
de Araujo, Flavio Eduardo Saraiva
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Martins, Thiago Fernandes
;
Ramos, Carlos Celso Mendonca
;
Nogueira, Rafael Michael Silva
;
Faccini, Joao Luiz Horacio
;
Tavares, Mariana Avelar
;
de Lima, Nicolas Jalowitzki
;
de Almeida Junior, Eduardo Bezerra
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de Sousa-Paula, Lucas Christian
;
Dantas-Torres, Filipe
;
da Silva Krawczak, Felipe
;
Costa-Junior, Livio Martins
;
Labruna, Marcelo Bahia
;
Dall'Agnol, Leonardo Teixeira
;
Luz, Hermes Ribeiro
Total Authors: 15
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| Document type: | Journal article |
| Source: | PARASITES & VECTORS; v. 16, n. 1, p. 13-pg., 2023-10-27. |
| Abstract | |
Background The tick Amblyomma cajennense sensu stricto (A. cajennense s.s.) frequently parasitizes animals and humans in the Amazon biome, in addition to being a vector of Rickettsia amblyommatis. In the present study, we evaluated both the population dynamics of A. cajennense s.s. in a degraded area of the Amazon biome and the presence of rickettsial organisms in this tick population.Methods The study was carried out in a rural area of the Santa Ines municipality (altitude: 24 m a.s.l.), Maranhao state, Brazil. Ticks were collected from the environment for 24 consecutive months, from June 2021 to May 2023. The region is characterized by two warm seasons: a rainy season (November-May) and a dry season (June-October). We characterized the temporal activity of A. cajennense s.s. on the vegetation by examining questing activity for each life stage (larvae, nymphs, adults [males and females]) in relation to the dry and rainy season. Ticks collected in this study were randomly selected and individually tested by a TaqMan real-time PCR assay that targeted a 147-bp fragment of the rickettsial gltA gene.Results Overall, 1843 (62.4%) adults (52.6% females, 47.4% males), 1110 (37.6%) nymphs and 398 larval clusters were collected. All adult females and nymphs were morphologically identified as A. cajennense s.s. Larval activity was observed from April to December, with a peak from June to September (dry season); nymph abundance peaked from September to November (transition period between dry and rainy seasons); and adult ticks were abundant from October to May (spring/summer/early autumn). The infection rate by R. amblyommatis in A. cajennense s.s. ticks was at least 7% (7/99).Conclusion Our data suggest a 1-year generation pattern for A. cajennense s.s., with a well-defined seasonality of larvae, nymphs and adults in the Amazon biome. Larvae predominate during the dry season, nymphs are most abundant in the dry-rainy season transition and adults are most abundant in the rainy season. The presence of R. amblyommatis in adult ticks suggests that animals and humans in the study region are at risk of infection by this species belonging to the spotted fever group of Rickettsia. (AU) | |
| FAPESP's process: | 19/03167-0 - Dichotomic and pictorial taxonomic key for larvae of the genus Amblyomma (Parasitiformes: Ixodidae) that occur in Brazil, using optical and scanning electron microscopy for description and morphological redescription of the larval stage |
| Grantee: | Thiago Fernandes Martins |
| Support Opportunities: | Research Grants - Young Investigators Grants |
| FAPESP's process: | 20/05987-1 - Dichotomic and pictorial taxonomic key for larvae of the genus Amblyomma (Parasitiformes: Ixodidae) that occur in Brazil, using optical and scanning electron microscopy for description and morphological redescription of the larval stage |
| Grantee: | Thiago Fernandes Martins |
| Support Opportunities: | Scholarships in Brazil - Young Researchers |