Preliminary Study on Artificial versus Animal-Based Feeding Systems for Amblyomma Ticks (Acari: Ixodidae)

Abstract

Hard ticks pose a threat to animal and human health. Active life stages need to feed on a vertebrate host in order to complete their life cycle. To study processes such as tick-pathogen interactions or drug efficacy and pharmacokinetics, it is necessary to maintain tick colonies under defined laboratory conditions, typically using laboratory animals. The aim of this study was to test a membrane-based artificial feeding system (AFS) applicable for Amblyomma ticks using Amblyomma tonelliae as a biological model. Adult ticks from a laboratory colony were fed in a membrane-based AFS. For comparison, other A. tonelliae adults were fed on calf and rabbit. The proportions of attached (AFS: 76%; calf/rabbit: 100%) and engorged females (AFS: 47.4%; calf/rabbit: 100%) in the AFS were significantly lower compared to animal-based feeding (p = 0.0265). The engorgement weight of in vitro fed ticks (x¯ = 658 mg; SD ± 259.80) did not significantly differ from that of ticks fed on animals (p = 0.3272, respectively 0.0947). The proportion of females that oviposited was 100% for all three feeding methods. However, the incubation period of eggs (x¯ = 54 days; SD ± 7) was longer in the AFS compared to conventional animal-based feeding (p = 0.0014); x¯ = 45 days; SD ± 2 in the rabbit and (p = 0.0144). x¯ = 48 days; SD ± 2 in the calf). Egg cluster hatching (x¯ = 41%; SD ± 44.82) was lower in the AFS than in the other feeding methods (rabbit: x¯ = 74%; SD ± 20; p = 0.0529; calf: x¯ = 81%; SD ± 22; p = 0.0256). Although the attachment, development, and the hatching of AFS ticks were below those from animal-based feeding, the method may be useful in future experiments. Nevertheless, further experiments with a higher number of tick specimens (including immature life stages) and different attractant stimuli are required to confirm the preliminary results of this study and to evaluate the applicability of AFS for Amblyomma ticks as an alternative to animal-based feeding methods.

Optimization of artificial membrane feeding system for lone star ticks, Amblyomma americanum (Acari: Ixodidae), and experimental infection with Rickettsia amblyommatis (Rickettsiales: Rickettsiaceae)

“…Several AFS experimental settings have been described and examined for nearly 20 different tick species ( Waladde et al 1991 , Kröber and Guerin 2007 , Crispell et al 2019 , Vimonish et al 2020 , 2021 , González et al 2021 , Garcia Guizzo et al 2023 , Sebastian et al 2023 ). However, a significant knowledge gap exists in understanding the specific experimental conditions and reagents facilitating efficient attachment and subsequent feeding for individual tick species.…”

“…In contrast, the development of AFS for other medically relevant tick species, in particular Amblyomma spp. ( Sebastian et al 2023 ), has been delayed, partly due to the existing technical difficulties in developing AFS and working with ticks under laboratory conditions. Only 2 prior studies reported AFS applications for A. americanum despite the public health significance of this tick species ( Bullard et al 2016 , Li et al 2019 ).…”

“…Over the last 3 decades, the development of artificial feeding systems (AFS) for ixodid ticks enabled investigators to study tick biology under various experimental conditions ( Waladde et al 1991 , Kröber and Guerin 2007 , Crispell et al 2019 , Vimonish et al 2020 , 2021 , González et al 2021 , Garcia Guizzo et al 2023 , Sebastian et al 2023 ). In particular, the generation of siliconized artificial membranes revolutionized AFS and allowed investigators to use different chemical and biological substances to enhance tick attachment and maintain feeding to repletion ( Kröber and Guerin 2007 , Andrade et al 2014 ).…”

Artificial Feeding Systems for Vector-Borne Disease Studies

“…However, one of the primary concerns with artificial feeding membranes is the potential for altered vector behavior due to variations in vector feeding conditions. Some studies have indicated that feeding behaviors and infection rates might differ between vectors feeding on artificial membranes compared to natural hosts [ 116 , 142 , 143 , 144 ], which could influence the reliability of experimental outcomes [ Table 1 ]. The primary challenge in employing artificial membranes for tick research is mimicking the complex feeding environment encountered by ticks during host attachment, as they secrete a combination of saliva and cement-like substances to facilitate attachment and blood feeding, involving intricate biochemical interactions and structural adaptations [ 145 ].…”