scholarly journals Tick Saliva and the Alpha-Gal Syndrome: Finding a Needle in a Haystack

Author(s):  
Surendra Raj Sharma ◽  
Shahid Karim

Ticks and tick-borne diseases are significant public health concerns. Bioactive molecules in tick saliva facilitate prolonged blood-feeding and transmission of tick-borne pathogens to the vertebrate host. Alpha-gal syndrome (AGS), a newly reported food allergy, is believed to be induced by saliva proteins decorated with a sugar molecule, the oligosaccharide galactose-⍺-1,3-galactose (α-gal). This syndrome is characterized by an IgE antibody-directed hypersensitivity against α-gal. The α-gal antigen was discovered in the salivary glands and saliva of various tick species including, the Lone Star tick (Amblyomma americanum). The underlying immune mechanisms linking tick bites with α-gal-specific IgE production are poorly understood and are crucial to identify and establish novel treatments for this disease. This article reviews the current understanding of AGS and its involvement with tick species.

2021 ◽  
Vol 2 ◽  
Author(s):  
Patricia Román-Carrasco ◽  
Wolfgang Hemmer ◽  
Alejandro Cabezas-Cruz ◽  
Adnan Hodžić ◽  
José de la Fuente ◽  
...  

The α-Gal syndrome is a complex allergic disease characterized by the development of specific IgE antibodies against the carbohydrate galactose-α-1,3-galactose (α-Gal), an oligosaccharide present in cells and tissues of non-primate mammals. Individuals with IgE antibodies to α-Gal suffer from a delayed form of anaphylaxis following red meat consumption. There are several features that make the α-Gal syndrome such a unique allergic disease and distinguish it from other food allergies: (1) symptoms causing IgE antibodies are directed against a carbohydrate moiety, (2) the unusual delay between the consumption of the food and the onset of the symptoms, and (3) the fact that primary sensitization to α-Gal occurs via tick bites. This review takes a closer look at the immune response against α-Gal, in healthy and in α-Gal allergic individuals. Furthermore, the similarities and differences between immune response against α-Gal and against the other important glycan moieties associated with allergies, namely cross-reactive carbohydrate determinants (CCDs), are discussed. Then different mechanisms are discussed that could contribute to the delayed onset of symptoms after consumption of mammalian meat. Moreover, our current knowledge on the role of tick bites in the sensitization process is summarized. The tick saliva has been shown to contain proteins carrying α-Gal, but also bioactive molecules, such as prostaglandin E2, which is capable of stimulating an increased expression of anti-inflammatory cytokines while promoting a decrease in the production of proinflammatory mediators. Together these components might promote Th2-related immunity and trigger a class switch to IgE antibodies directed against the oligosaccharide α-Gal. The review also points to open research questions that remain to be answered and proposes future research directions, which will help to get a better understanding and lead to a better management of the disease.


2018 ◽  
Author(s):  
Gary Crispell ◽  
Scott P. Commins ◽  
Stephanie A. Archer-Hartman ◽  
Shailesh Choudhary ◽  
Guha Dharmarajan ◽  
...  

AbstractDevelopment of specific IgE antibodies to the oligosaccharide galactose-α-1, 3-galactose (α-gal) following tick bites has been shown to be the source of red meat allergy. In this study, we investigated the presence of α-gal in four tick species: the lone-star tick (Amblyomma americanum), the Gulf-Coast tick (Amblyomma maculatum), the American dog tick (Dermacentor variabilis), and the black-legged tick (Ixodes scapularis) by using a combination of immunoproteome, carbohydrate analysis, and basophil activation approaches. Using anti-α-gal antibodies, α-gal was identified in the salivary glands of bothAm. americanumandIx. scapularis, whileAm. maculatumandDe. variabilisappeared to lack the sugar. PNGase F treatment confirmed the deglycosylation of N-linked α-gal-containing proteins in tick salivary glands. Immunolocalization of α-gal moieties to the salivary secretory vesicles of the salivary acini also confirmed the secretory nature of α-gal-containing antigens in ticks.Am. americanumticks were fed human blood (lacks α-gal) using an artificial membrane feeding system to determine the source of α-gal. N-linked glycan analysis revealed thatAm. americanumandIx. scapularishave α-gal in their saliva and salivary glands, butAm. maculatumcontains no detectable quantity. Salivary samples fromAm. americanumandIx. scapularisstimulated activation of basophils primed with plasma from α-gal allergic subjects. Together, our data support the idea that bites from certain tick species may specifically create a risk for the development of α-gal-specific IgE and hypersensitivity reactions in humans. Alpha-Gal syndrome challenges the current food allergy paradigm and broadens opportunities for future research.


Author(s):  
Heather L Kopsco ◽  
Roland J Duhaime ◽  
Thomas N Mather

Abstract Burgeoning cases of tick-borne disease present a significant public health problem in the United States. Passive tick surveillance gained traction as an effective way to collect epidemiologic data, and in particular, photograph-based tick surveillance can complement in-hand tick specimen identification to amass distribution data and related encounter demographics. We compared the Federal Information Processing Standards (FIPS) code of tick photos submitted to a free public identification service (TickSpotters) from 2014 to 2019 to published nationwide county reports for three tick species of medical concern: Ixodes scapularis Say (Ixodida: Ixodidae), Ixodes pacificus Cooley and Kohls (Ixodida: Ixodidae), and Amblyomma americanum Linneaus (Ixodida: Ixodidae). We tallied the number of TickSpotters submissions for each tick species according to “Reported” or “Established” criteria per county, and found that TickSpotters submissions represented more than half of the reported counties of documented occurrence, and potentially identified hundreds of new counties with the occurrence of these species. We detected the largest number of new county reports of I. scapularis presence in Michigan, North Carolina, and Texas. Tick image submissions revealed potentially nine new counties of occurrence for I. pacificus, and we documented the largest increase in new county reports of A. americanum in Kentucky, Illinois, Indiana, and Ohio. These findings demonstrate the utility of crowdsourced photograph-based tick surveillance as a complement to other tick surveillance strategies in documenting tick distributions on a nationwide scale, its potential for identifying new foci, and its ability to highlight at-risk localities that might benefit from tick-bite prevention education.


2020 ◽  
Vol 57 (5) ◽  
pp. 1532-1538
Author(s):  
Cedar Mitchell ◽  
Megan Dyer ◽  
Feng-Chang Lin ◽  
Natalie Bowman ◽  
Thomas Mather ◽  
...  

Abstract Tick-borne diseases are a growing threat to public health in the United States, especially among outdoor workers who experience high occupational exposure to ticks. Long-lasting permethrin-impregnated clothing has demonstrated high initial protection against bites from blacklegged ticks, Ixodes scapularis Say (Acari: Ixodidae), in laboratory settings, and sustained protection against bites from the lone star tick, Amblyomma americanum (L.) (Acari: Ixodidae), in field tests. However, long-lasting permethrin impregnation of clothing has not been field tested among outdoor workers who are frequently exposed to blacklegged ticks. We conducted a 2-yr randomized, placebo-controlled, double-blinded trial among 82 outdoor workers in Rhode Island and southern Massachusetts. Participants in the treatment arm wore factory-impregnated permethrin clothing, and the control group wore sham-treated clothing. Outdoor working hours, tick encounters, and bites were recorded weekly to assess protective effectiveness of long-lasting permethrin-impregnated garments. Factory-impregnated clothing significantly reduced tick bites by 65% in the first study year and by 50% in the second year for a 2-yr protective effect of 58%. No significant difference in other tick bite prevention method utilization occurred between treatment and control groups, and no treatment-related adverse outcomes were reported. Factory permethrin impregnation of clothing is safe and effective for the prevention of tick bites among outdoor workers whose primary exposure is to blacklegged ticks in the northeastern United States.


Author(s):  
Marvin S Godsey ◽  
Dominic Rose ◽  
Kristin L Burkhalter ◽  
Nicole Breuner ◽  
Angela M Bosco-Lauth ◽  
...  

Abstract Following the recent discovery of Bourbon virus (BRBV) as a human pathogen, and the isolation of the virus from Amblyomma americanum (L.) collected near the location of a fatal human case, we undertook a series of experiments to assess the laboratory vector competence of this tick species for BRBV. Larval ticks were infected using an immersion technique, and transstadial transmission of virus to the nymphal and then to the adult stages was demonstrated. Transstadially infected nymphs transmitted virus to adult ticks at very high rates during cofeeding, indicating the presence of infectious virus in the saliva of engorging ticks. Vertical transmission by transstadially infected females to their progeny occurred, but at a low rate. Rabbits fed on by infected ticks of all active life stages developed high titers of antibody to the virus, demonstrating host exposure to BRBV antigens/live virus during tick blood feeding. These results demonstrate that A. americanum is a competent vector of BRBV and indicate that cofeeding could be critical for enzootic maintenance.


Author(s):  
Ashley P G Dowling ◽  
Sean G Young ◽  
Kelly Loftin

Abstract Tick-borne diseases (TBD) in humans have dramatically increased over recent years and although the bulk of cases are attributable to Lyme Disease in the Northeastern US, TBDs like spotted fever rickettsiosis and ehrlichiosis heavily impact other parts of the country, namely the mid-south. Understanding tick and pathogen distributions and prevalence traditionally requires active surveillance, which quickly becomes logistically and financially unrealistic as the geographic area of focus increases. We report on a community science effort to survey ticks across Arkansas to obtain updated data on tick distributions and prevalence of human tick-borne disease-causing pathogens in the most commonly encountered ticks. During a 20-mo period, Arkansans submitted 9,002 ticks from 71 of the 75 counties in the state. Amblyomma americanum was the most common tick species received, accounting for 76% of total tick submissions. Nearly 6,000 samples were screened for spotted fever group Rickettsia (SFGR) and Ehrlichia, resulting in general prevalence rates of 37.4 and 5.1%, respectively. In addition, 145 ticks (2.5%) were infected with both SFGR and Ehrlichia. Arkansas Department of Health reported 2,281 spotted fever and 380 ehrlichiosis cases during the same period as our tick collections. Since known SFGR vectors Dermacentor variabilis and Amblyomma maculatum were not the most common ticks submitted, nor did they have the highest prevalence rates of SFGR, it appears that other tick species play the primary role in infecting humans with SFGR. Our investigation demonstrated the utility of community science to efficiently and economically survey ticks and identify vector-borne disease risk in Arkansas.


Author(s):  
Muhammad Jamil ◽  
Muhammad Kashif ◽  
Habibullah ◽  
Muhammad Mubeen ◽  
Ghulam Jelani ◽  
...  

Ticks are blood-feeding obligate ectoparasites that belong to order Arachnida with three main families (Ixodidae, Argasidae, and Nuttalleillidae). Ticks transmit viral, bacterial, and zoonotic diseases in humans, and animals (wild and domestic). Ticks directly and indirectly affect the livestock industry which plays an important role in the rural economy of Pakistan. These are the main source of income and a source of food for poor people. The current study was conducted to identify the tick species infesting livestock in Dera Ismail Khan Pakistan. For this purpose, different farms were randomly visited and 130 ticks were collected from 200 scanned animals.  The collected ticks were identified to species level using morphological keys. In the current study, four tick species were identified as Rhipicephalus sanguineus, Hyalomma marginatum, Hyalomma anatolicum, and Dermacentor marginatus were identified. The most dominant species were Hy. anatolicum (35.39%) followed by R. sanguineus (30.00%), Hy. marginatum (23.85%) and D. marginatus (10.77%). Hy. anatolicum was the predominant tick species and accounted for 35.39% of the ticks. Tick infestation was highest in buffaloes followed by cows, sheep, and goats. Tail and ear were the most preferable sites for tick infestation than other body parts.


2016 ◽  
Vol 10 (1) ◽  
pp. e0004323 ◽  
Author(s):  
Tae Kwon Kim ◽  
Lucas Tirloni ◽  
Antônio F. M. Pinto ◽  
James Moresco ◽  
John R. Yates ◽  
...  

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Parisa Soltan-Alinejad ◽  
Zahra Ramezani ◽  
Hamideh Edalat ◽  
Zakkyeh Telmadarraiy ◽  
Farrokh Dabiri ◽  
...  

Abstract Objectives Hard ticks (Acari: Ixodidae) are ectoparasites of medical and veterinary importance. They are obligate blood-feeding vectors with the ability to transmit a wide variety of pathogens. Standard morphological keys are normally used for the identification of tick species. However, considering the importance of accurate species identification and the determination of bio-ecological characteristics of species, relying on morphological keys alone can be questionable. In this study, two DNA fragments (ITS2 and COI) were selected for phylogenetic evaluation of Iranian hard tick species belonging to the genera Dermacentor, Hyalomma, and Rhipicephalus. Results 1229 specimens of Dermacentor marginatus, D. niveus, Hyalomma anatolicum, Rhipicephalus bursa, and R. sanguineuss.l constituting 11 populations were collected from three different climatic and zoogeographical zones in Iran. Morphological studies revealed notable differences in important morphological characteristics between different populations of D. marginatus. The results of ITS2 sequence analysis provided additional evidence which supports the conspecificity of D. niveus and D. marginatus. Contrary to this finding, the sequence analysis of COI and phylogeny favored the separation of the two species. Given the greater importance of COI in identifying and discriminating species, a possibility heterospecificity between the two species should be considered.


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