Preliminary studies on the effect of Anaplasma marginale antibodies ingested by Dermacentor andersoni ticks (Acari:Ixodidae) with their blood meal on infections in salivary glands

1996 ◽  
Vol 20 (6) ◽  
pp. 297-311 ◽  
Author(s):  
Katherine M. Kocan ◽  
Edmour F. Blouin ◽  
Guy H. Palmer ◽  
Inge S. Eriks ◽  
Wanda L. Edwards ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Blood Meal ◽  
Anaplasma Marginale ◽  
Dermacentor Andersoni

Salivary glands of the sand fly Phlebotomus papatasi contain pharmacologically active amounts of adenosine and 5′-AMP

1999 ◽  
Vol 202 (11) ◽  
pp. 1551-1559 ◽  
Author(s):  
J.M. Ribeiro ◽  
O. Katz ◽  
L.K. Pannell ◽  
J. Waitumbi ◽  
A. Warburg
Keyword(s):  
Mass Spectrometry ◽  
Salivary Gland ◽  
Salivary Glands ◽  
Blood Meal ◽  
Protein Phosphatase ◽  
Sand Fly ◽  
Phlebotomus Papatasi ◽  
Pharmacologically Active ◽  
Phosphatase Substrate ◽  
Allosteric Modification

Salivary gland homogenates of the sand fly Phlebotomus papatasi contain large amounts of adenosine and 5′-AMP, of the order of 1 nmol per pair of glands, as demonstrated by liquid chromatography, ultraviolet spectrometry, mass spectrometry and bioassays. These purines, 75–80 % of which are secreted from the glands following a blood meal, have vasodilatory and anti-platelet activities and probably help the fly to obtain a blood meal. Salivary 5′-AMP is also responsible for the previously reported protein phosphatase inhibitor in the salivary glands of P. papatasi, which is shown to be artifactual in nature as a result of allosteric modification by AMP of the phosphatase substrate used (phosphorylase a).

scholarly journals Specific Expression of Anaplasma marginale Major Surface Protein 2 Salivary Gland Variants Occurs in the Midgut and Is an Early Event during Tick Transmission

2002 ◽  
Vol 70 (1) ◽  
pp. 114-120 ◽  
Author(s):  
Christiane V. Löhr ◽  
Fred R. Rurangirwa ◽  
Terry F. McElwain ◽  
David Stiller ◽  
Guy H. Palmer
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Surface Protein ◽  
Anaplasma Marginale ◽  
Mammalian Host ◽  
Early Event ◽  
Variant Selection ◽  
Specific Expression ◽  
Major Surface Protein ◽  
Major Surface

ABSTRACT Infectivity of Anaplasma spp. develops when infected ticks feed on a mammalian host (transmission feed). Specific Anaplasma marginale major surface protein 2 (MSP2) variants are selected for within the tick and are expressed within the salivary glands. The aims of this study were to determine when and where MSP2 variant selection occurs in the tick, how MSP2 expression is regulated in salivary glands of transmission-feeding ticks, and whether the number of A. marginale organisms per salivary gland is significantly increased during transmission feeding. The South Idaho strain of A. marginale was used, as MSP2 expression is restricted to two variants, SGV1 and SGV2, in Dermacentor andersoni. Using Western blot, real-time PCR, and DNA sequencing analyses it was shown that restriction and expression of MSP2 occurs early in the midgut within the first 48 h of the blood meal, when ticks acquire infection. A. marginale is present in the tick salivary glands before transmission feeding is initiated, but the msp2 mRNA and MSP2 protein levels per A. marginale organism increase only minimally and transiently in salivary glands of transmission-feeding ticks compared to that of unfed ticks. A. marginale numbers per tick increase gradually in salivary glands of both transmission-fed and unfed ticks. It is concluded that MSP2 variant selection is an early event in the tick and that MSP2 variants SGV1 and SGV2 are expressed both in the midgut and salivary glands. While MSP2 may be required for infectivity, there is no strict temporal correlation between MSP2 expression and the development of infectivity.

scholarly journals Identification of Midgut and Salivary Glands as Specific and Distinct Barriers to Efficient Tick-Borne Transmission of Anaplasma marginale

2007 ◽  
Vol 75 (6) ◽  
pp. 2959-2964 ◽  
Author(s):  
Massaro W. Ueti ◽  
James O. Reagan ◽  
Donald P. Knowles ◽  
Glen A. Scoles ◽  
Varda Shkap ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Disease Outbreaks ◽  
Subsequent Development ◽  
Anaplasma Marginale ◽  
Positive Control ◽  
Midgut Epithelium ◽  
Developmental Cycle ◽  
Infected Blood ◽  
Specific Barriers ◽  
Efficient Transmission

ABSTRACT Understanding the determinants of efficient tick-borne microbial transmission is needed to better predict the emergence of highly transmissible pathogen strains and disease outbreaks. Although the basic developmental cycle of Anaplasma and Ehrlichia spp. within the tick has been delineated, there are marked differences in the ability of specific strains to be efficiently tick transmitted. Using the highly transmissible St. Maries strain of Anaplasma marginale in Dermacentor andersoni as a positive control and two unrelated nontransmissible strains, we identified distinct barriers to efficient transmission within the tick. The Mississippi strain was unable to establish infection at the level of the midgut epithelium despite successful ingestion of infected blood following acquisition feeding on a bacteremic animal host. This inability to colonize the midgut epithelium prevented subsequent development within the salivary glands and transmission. In contrast, A. marginale subsp. centrale colonized the midgut and then the salivary glands, replicating to a titer indistinguishable from that of the highly transmissible St. Maries strain and at least 100 times greater than that previously associated with successful transmission. Nonetheless, A. marginale subsp. centrale was not transmitted, even when a large number of infected ticks was used for transmission feeding. These results establish that there are at least two specific barriers to efficient tick-borne transmission, the midgut and salivary glands, and highlight the complexity of the pathogen-tick interaction.

Tick salivary glands: function, physiology and future

Parasitology ◽  
2004 ◽  
Vol 129 (S1) ◽  
pp. S67-S81 ◽  
Author(s):  
A. S. BOWMAN ◽  
J. R. SAUER
Keyword(s):  
Salivary Glands ◽  
Blood Meal ◽  
Cell Biology ◽  
Expressed Sequence Tag ◽  
Extended Period ◽  
Feeding Site ◽  
Route Of Transmission ◽  
The Many ◽  
Vector Competency ◽  
Tick Salivary Glands

The salivary glands are the organs of osmoregulation in ticks and, as such, are critical to the biological success of ticks both during the extended period off the host and also during the feeding period on the host. Absorption of water vapour from unsaturated air into hygroscopic fluid produced by the salivary glands permit the tick to remain hydrated and viable during the many months between blood-meals. When feeding, the tick is able to return about 70% of the fluid and ion content of the blood-meal into the host by salivation into the feeding site. This saliva also contains many bioactive protein and lipid components that aid acquisition of the blood-meal. The salivary glands are the site of pathogen development and the saliva the route of transmission. The importance of the multifunctional salivary glands to tick survival and vector competency makes the glands a potential target for intervention. Here we review the cell biology of tick salivary glands and discuss the application of new approaches such as expressed sequence tag projects and RNA interference to this important area in the field of tick and tick-borne pathogen research.

Transmission of California encephalitis virus by mosquitoes

1968 ◽  
Vol 14 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Max A. Chernesky
Keyword(s):  
Aedes Aegypti ◽  
Salivary Glands ◽  
Blood Meal ◽  
Neutralizing Antibodies ◽  
Animal Species ◽  
Virus Titer ◽  
Virus Detection ◽  
Virus Growth ◽  
Average Maximum ◽  
Subcutaneous Inoculation

Transmission of California encephalitis (CE) virus strain R2929 by groups of Aedes vexans (Meigen) mosquitoes to rabbits was accomplished 7 and 9 days after the insects had imbibed an infective blood meal. Aedes aegypti (L.) mosquitoes transmitted virus to newly hatched chickens by biting them 48, 96, and 144 hours after intrathoracic injection.CE vires was found in gut, thorax, legs, and salivary glands of pools of Aedes triseriatus (Say), Aedes canadensis (Theobald), and A. vexans mosquitoes after intrathoracic injection of 101.3 mouse LD50 per 0.003 ml of virus. Salivary glands contained a maximum virus titer of 105.0 mouse LD50 per anatomical unit 5 days after injection. A. aegypti mosquitoes also supported virus growth after intrathoracic injection but yielded higher virus titers (106.3 mouse LD50) in the salivary glands.The infection threshold of A. vexans fed CE virus was 102.0LD50 per insect. Immediately after ingestion of 102.0 LD50 of virus only the gut washings contained virus. Detection of virus was not accomplished again until 4 days later. Average maximum titers of 104.5 LD50 per salivary glands were found after 8 days of extrinsic incubation. The infection threshold of A. aegypti fed CE virus exceeded 104.5 LD50 per insect.New Zealand white rabbits and Leghorn chickens circulated CE virus in their blood, which attained peak titers of 102.5 mouse LD50 per 0.03 ml 48 and 72 hours respectively after subcutaneous inoculation, but weaned mice did not develop viremia. All three animal species produced neutralizing antibodies to CE virus 21 days after inoculation.

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