Browsing by Author "de Leon, Adalberto A. Perez"

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    Association of Salivary Cholinesterase With Arthropod Vectors of Disease
    Temeyer, Kevin B.; Schlechte, Kristie G.; Olafson, Pia U.; Drolet, Barbara S.; Tidwell, Jason P.; Osbrink, Weste L. A.; Showler, Allan T.; Gross, Aaron D.; de Leon, Adalberto A. Perez (2020-11)
    Acetylcholinesterase (AChE) was previously reported to be present in saliva of the southern cattle tick, Rhipicephalus (Boophilus) microplus (Canestrini), with proposed potential functions to 1) reduce acetylcholine toxicity during rapid engorgement, 2) modulate host immune responses, and 3) to influence pathogen transmission and establishment in the host. Potential modulation of host immune responses might include participation in salivary-assisted transmission and establishment of pathogens in the host as has been reported for a number of arthropod vector-borne diseases. If the hypothesis that tick salivary AChE may alter host immune responses is correct, we reasoned that similar cholinesterase activities might be present in saliva of additional arthropod vectors. Here, we report the presence of AChE-like activity in the saliva of southern cattle ticks, Rhipicephalus (Boophilus) microplus; the lone star tick, Amblyomma americanum (Linnaeus); Asian tiger mosquitoes, Aedes albopictus (Skuse); sand flies, Phlebotomus papatasi (Scopoli); and biting midges, Culicoides sonorensis Wirth and Jones. Salivary AChE-like activity was not detected for horn flies Haematobia irritans (L.), stable flies Stomoxys calcitrans (L.), and house flies Musca domestica L. Salivary cholinesterase (ChE) activities of arthropod vectors of disease-causing agents exhibited various Michaelis-Menten K-M values that were each lower than the K-M value of bovine serum AChE. A lower K-M value is indicative of higher affinity for substrate and is consistent with a hypothesized role in localized depletion of host tissue acetylcholine potentially modulating host immune responses at the arthropod bite site that may favor ectoparasite blood-feeding and alter host defensive responses against pathogen transmission and establishment.
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    Multistate Infestation with the Exotic Disease-Vector Tick Haemaphysalis longicornis - United States, August 2017-September 2018
    Ben Beard, C.; Occi, James; Bonilla, Denise L.; Egizi, Andrea M.; Fonseca, Dina M.; Mertins, James W.; Backenson, Bryon P.; Bajwa, Waheed I.; Barbarin, Alexis M.; Bertone, Matthew A.; Brown, Justin; Connally, Neeta P.; Connell, Nancy D.; Eisen, Rebecca J.; Falco, Richard C.; James, Angela M.; Krell, Rayda K.; Lahmers, Kevin K.; Lewis, Nicole; Little, Susan E.; Neault, Michael; de Leon, Adalberto A. Perez; Randall, Adam R.; Ruder, Mark G.; Saleh, Meriam N.; Schappach, Brittany L.; Schroeder, Betsy A.; Seraphin, Leslie L.; Wehtje, Morgan; Wormser, Gary P.; Yabsley, Michael J.; Halperin, William (Centers for Disease Control and Prevention, 2018-11-30)
    Haemaphysalis longicornis is a tick indigenous to eastern Asia and an important vector of human and animal disease agents, resulting in such outcomes as human hemorrhagic fever and reduction of production in dairy cattle by 25%. H. longicornis was discovered on a sheep in New Jersey in August 2017 (1). This was the first detection in the United States outside of quarantine. In the spring of 2018, the tick was again detected at the index site, and later, in other counties in New Jersey, in seven other states in the eastern United States, and in Arkansas. The hosts included six species of domestic animals, six species of wildlife, and humans. To forestall adverse consequences in humans, pets, livestock, and wildlife, several critical actions are indicated, including expanded surveillance to determine the evolving distribution of H. longicornis, detection of pathogens that H. longicornis currently harbors, determination of the capacity of H. longicornis to serve as a vector for a range of potential pathogens, and evaluation of effective agents and methods for the control of H. longicornis.