Physiological characterization of the hematophagy of Ornithodoros rostratus (Acari: Argasidae) on live hosts.
Ornithodoros rostratus is an argasid tick and its importance is based on its hematophagy and the resulting transmission of pathogens such as Rickettsia rickettsii and Coxiella burnetii to its vertebrate hosts. In the face of a lack of physiological studies related to hematophagy in argasid ticks, this paper aims to identify and characterize the events that occur throughout the feeding by O. rostratus on live hosts. Electrical signals and alterations on the feeding site were monitored using intravital microscopy and electromyography. The analyses allowed for the characterization of four distinct events: suction, salivation, chelicerae movements and inactivity. Feeding was divided into two distinct phases: (1) penetration of mouthparts (when only salivation and chelicerae movements occurred) and the formation of the feeding pool (salivation and chelicerae movements with the first signs of suction) and (2) engorgement, during which chelicerae movements ceased and blood intake took place in feeding complexes (salivation followed by suction). Variations in patterns of the electrical signals, suction frequency and salivation showed four distinct sub-phases: (2a) suction with electrical signals of irregular shape, increased suction frequency and decreased salivation frequency throughout blood feeding; (2b) suction with electrical signals of symmetrical shape, high suction rates (3.8 Hz on average) and feeding complexes lasting for 7.7 s; (2c) suction with electrical signals of irregular shape, high suction frequency and feeding complex lasting 11.5 s; and (2d) electrical signals with no profile and the longest feeding complexes (14.5 s). Blood feeding ended with the withdrawal of the mouthparts from the host's skin.
Physiology of Hematophagous Insects Laboratory, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.
Gabriel Cerqueira Alves
GC
Costa
Physiology of Hematophagous Insects Laboratory, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.
Adriana Coelho
AC
Soares
Physiology of Hematophagous Insects Laboratory, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.|National Institute of Molecular Entomology, Rio de Janeiro 21941-591, Brazil.
Marcos Horácio
MH
Pereira
Physiology of Hematophagous Insects Laboratory, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.|National Institute of Molecular Entomology, Rio de Janeiro 21941-591, Brazil.
Nelder Figueiredo
NF
Gontijo
Physiology of Hematophagous Insects Laboratory, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.
Maurício Roberto Viana
MR
Sant'Anna
Physiology of Hematophagous Insects Laboratory, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil rnaraujo@icb.ufmg.br.|National Institute of Molecular Entomology, Rio de Janeiro 21941-591, Brazil.
Ricardo Nascimento
0000-0002-1272-4386
RN
Araujo
D000818:Animals; D004576:Electromyography; D055724:Electrophysiological Phenomena; D005247:Feeding Behavior / Q000502:physiology*; D006790:Host-Parasite Interactions / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D007814:Larva / Q000502:physiology; D051379:Mice; D026861:Ornithodoros / Q000502:physiology*; D012472:Salivation / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013396:Suction; D013997:Time Factors
Blood feeding; Electromyogram; Intravital microscopy; Ornithodoros rostratus; Pharyngeal pump