Tick Artificial Membrane Feeding for Ixodes scapularis

Summary

Presented here is a method to blood feed ticks in vitro via an artificial membrane system to allow for partial or full engorgement of a variety of tick life stages.

Abstract

Ticks and their associated diseases are an important topic of study due to their public health and veterinary burden. However, the feeding requirements of ticks during both study and rearing can limit experimental questions or the ability of labs to research ticks and their associated pathogens. An artificial membrane feeding system can reduce these problems and open up new avenues of research that may not have been possible with traditional animal feeding systems. This study describes an artificial membrane feeding system that has been refined for feeding and engorgement success for all Ixodes scapularis life stages. Moreover, the artificial membrane feeding system described in this study can be modified for use with other tick species through simple refinement of the desired membrane thickness. The benefits of an artificial membrane feeding system are counterbalanced by the labor intensiveness of the system, the additional environmental factors that may impact feeding success, and the need to refine the technique for each new species and life stage of ticks.

Introduction

Tick-borne diseases strongly impact the health of humans and animals across the world, being responsible for more than two-thirds of all vector-associated illness in the USA from 2004 to 2016¹. Additionally, case numbers have been growing in recent years, with more people and livestock being affected by ticks and their associated diseases^2,3. While there are likely numerous causes for the upward trend in case numbers, the changing climate is an important factor^3,4. The predicted ongoing increase in the number of tick-borne disea....

Protocol

1. Preparing the tick membrane chamber

1. Prepare a flat, non-porous surface such as a plane of glass or ceramic-coated metal base of an arm stand by wiping it down with 70% ethanol and then cover it with a single layer of plastic wrap, making sure that the plastic wrap is flat and without bubbles or wrinkles (see Figure 1A).
2. Tape down 100% rayon lens cleaning paper to the prepared surface. Ensure it is flat and slightly taut with tape across all four sides of the paper. Two pieces of 4 in x 6 in lens paper can be made into membranes using the volumes described in step 1.3.
   NOTE: This is sufficie....

Results

A successful feeding depends on whether a partial or full engorgement is desired. Successfully fed I. scapularis turn a shade of gunmetal grey for adults and detach on their own from the membrane. However, if they are at least pea-sized, they may be detached from the membrane when finishing up the feeding. For immature stages of I. scapularis, the size for fully engorged ticks varies, and because, unlike adults, they do not exhibit a color change, detachment is the best way to determine if a tick is ful.......

Discussion

Artificial membrane feeding of ticks provides a useful tool for a variety of experimental procedures, but is not likely to replace animal feeding for all applications. Maintaining large colonies of ticks at all life stages without animal feeding is generally untenable. Instead, the artificial feeding system is valuable for other purposes such as infecting ticks with pathogens not supported by model hosts, evaluating the impacts of controlled dosages of compounds or microorganisms on the ticks in a simplified feeding envi.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
00-10 Hardness Silicone	Smooth-On	Ecoflex 00-10	Trial size from Smooth-On Store
00-50 Hardness Silicone	Smooth-On	Ecoflex 00-50	Trial size from Smooth-On Store
30 Hardness Silicone	Smooth-On	Mold Star 30	Trial size from Smooth-On Store
6-well cell culture plates	Corning Incorporated	3516
Adenosine triphosphate (ATP)	Millipore Sigma	A1852-1VL	Used to make an aqueous solution of 3 mM ATP that has been filter sterlized via 0.2 micometer filter
Bovine blood	HemoStat	DBB500	Mechanically defibrinated; 500 mL is usually sufficient for one experiment
Clingwrap	Fisherbrand	22-305654
Filter Paper	Fisherbrand	09-790-2C	Autoclave and let cool before using. Can use Fine quality instead of medium too
Fluon (aqueous polytetrafluoroethylene)	Bioquip	2871	Available from other sources such as https://canada-ant-colony.com/products/fluon-ptfe-10ml
Glucose	Millipore Sigma	G8270-100G
Hexane	Millipore Sigma	139386-100ML
Lens paper	Fisherbrand	11-995	100% rayon
Nystatin	Gold Biotechnology	N-750-10
Parafilm	Fisherbrand	S37440
Penicillin/streptomycin/fungizone	Gibco	15240-096	Or equivalent generic with concentration as follows (10,000 units/mL of penicillin, 10,000 µg/mL of streptomycin, and 25 µg/mL of Amphotericin B)
Phagostimulant	Made in House		Collected from prior tick feeds
Polycarbonate Pipe	McMaster-Carr	8585K204	Cut to 45 mm length, 1.25 inch outer diameter, 1 inch inner diameter. Cutting requires a chop saw grinding wheel.
Rubber O-rings	McMaster-Carr	9452K38	5 mm thick, 1.25 inch inner diameter
Soft touch forceps	VWR	470315-238
Super glue			cyanoacrylate glue
Unryu paper	Art supply stores		mulberry fiber 10 g/m2. Purchased at Wet Paint art supply store, St. Paul, MN, USA