Symbiont-regulated serotonin biosynthesis modulates tick feeding activity

Author(s):  
Zhengwei Zhong ◽  
Ting Zhong ◽  
Yeqing Peng ◽  
Xiaofeng Zhou ◽  
Zhiqian Wang ◽  
...  
2021 ◽  
Author(s):  
George F. Aranjuez ◽  
Amanda G. Lasseter ◽  
Mollie W. Jewett

Lyme disease is a multi-stage inflammatory disease caused by the spirochete Borrelia burgdorferi transmitted through the bite of an infected Ixodes scapularis tick. We previously discovered a B. burgdorferi infectivity gene, bbk13 , that facilitates mammalian infection by promoting spirochete population expansion in the skin inoculation site. Initial characterization of bbk13 was carried out using an intradermal needle inoculation model of mouse infection, which does not capture the complex interplay of the pathogen-vector-host triad of natural transmission. Herein, we aimed to understand the role of bbk13 in the enzootic cycle of B. burgdorferi . B. burgdorferi lacking bbk13 were unable to be acquired by naive larvae fed on needle inoculated mice. Using a capsule-feeding approach to restrict tick feeding activity to a defined skin site, we determined that delivery by tick bite alleviated the population expansion defect in the skin observed after needle inoculation of Δ bbk13 B. burgdorferi . Despite overcoming the early barrier in the skin, Δ bbk13 B. burgdorferi remained attenuated for distal tissue colonization after tick transmission. Disseminated infection of Δ bbk13 B. burgdorferi was improved in needle inoculated immunocompromised mice. Together, we established that bbk13 is crucial to the maintenance of B. burgdorferi in the enzootic cycle and that bbk13 is necessary beyond early infection in the skin, likely contributing to host immune evasion. Moreover, our data highlight the critical interplay between the pathogen, vector, and host as well as the distinct molecular genetic requirements for B. burgdorferi to survive at the pathogen-vector-host interface and to achieve productive disseminated infection.


Parasitology ◽  
1996 ◽  
Vol 112 (6) ◽  
pp. 571-580 ◽  
Author(s):  
T. R. Barton ◽  
M. P. Harris ◽  
S. Wanless ◽  
D. A. Elston

SUMMARYWe investigated the timing of seasonal activity of the seabird tick Ixodes uriae by examining engorgement rates of off-host ticks and the prevalence of infested common guillemots (Uria aalge) and kittiwakes (Rissa tridactyla) on the Isle of May, Scotland. More than 99% of I. uriae fed during the period late April to early August which coincided with the seabird breeding season. No ticks fed in the autumn and winter, and none over-wintered in the engorged state. Peak tick feeding activity was during the hosts' incubation period in May and early June, when over 70% of birds were parasitized. Few ticks were active when guillemot chicks were being brooded, or during the early part of kittiwake chick-rearing. Adult female tick feeding peaked in the first week of June, while nymphal and larval activity peaked in the third week of May. Adult female ticks fed later than nymphs on guillemots and larvae on both guillemots and kittiwakes; however, there was considerable temporal overlap in the feeding periods of the 3 stages on both hosts. All larvae and nymphs fed in May and early June, but up to 18% of adult females remained unengorged at this time, and probably deferred feeding by 1 year. A small proportion of individuals which fed as larvae in May appeared to feed again as nymphs in July of the same season, thereby shortening their life-cycle by 1 year. The duration of the life-cycle of I. uriae on the Isle of May is typically 3 years but varies from 2 to 4 years. Ticks feeding on guillemots did so significantly earlier than those feeding on kittiwakes, possibly because guillemots start breeding earlier in the year. Breeding of both guillemots and kittiwakes was later in 1994 than in 1993. This delayed the activity of all tick stages on kittiwakes and adult female ticks on guillemots, but did not affect the timing of activity of nymphs or larvae feeding on guillemots.


1998 ◽  
Vol 23 (4) ◽  
pp. 382-387 ◽  
Author(s):  
James O. Ochanda ◽  
Eva A. C. Oduor ◽  
Rachel Galun ◽  
Mabel O. Imbuga ◽  
Kosta Y. Mumcuoglu

SCISCITATIO ◽  
2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Djoko Rahardjo ◽  
Vinsa Cantya Prakasita ◽  
Marlen Aviati Sarah Pepiana

Malaria is known as an endemic disease that often causes death in Indonesia, especially in Papua. The malaria cases control in Papua has not been carried on based on data studies, therefore bionomic of Anopheles sp is important to be studied. Bionomics data are consisted of breeding places, resting places and feeding habits are from direct observation. Interviews and questionnaires were conducted to gain information about respondent behavior. Descriptive and qualitative data were then analyzed. The breeding places of Anopheles sp. were mostly found in swampy areas. Based on the feeding habit, the feeding activity of Anopheles sp. inside the house has only one biting peak at 23.00-02.00 WIT, while outside the house, biting peaks occurred at 21.00-22.00 WIT and 00.00-01.00 WIT. Resting place data shown that Anopheles sp. mostly found in piles of clothes and shoe racks. Recorded factors that affect mosquitos bionomics are temperature, humidity, salinity, pH, community behavior, and the presence of livestock. Environmental factors (temperature, humidity, salinity, and pH), habitual behavior of host (3M action, the habit of using insect repellent, mosquito repellent, and mosquito nets), the presence of livestock, and the type of bait blood type affect mosquito activity.


2005 ◽  
Vol 40 (2) ◽  
pp. 191-201 ◽  
Author(s):  
Nadia Berday ◽  
Driss Zaoui ◽  
Abdeljaouad Lamrini ◽  
Mustapha Abi

Abstract The effect of silver carp (Hypophthalmichthys molitrix Val.) feeding activity on the plankton communities in a high-rate pond technology system (HRPTS) effluent was investigated over a period of 100 days. The experiment was conducted at the experimental wastewater treatment plant of the Agronomic and Veterinary Medicine Institute (AVI) of Rabat, Morocco, using a HRPTS in a fish pond receiving the plant effluent. The effluent was highly dominated by phytoplankton (99.95%). Silver carp could survive and grow in the fish pond. Production was 37 kg with a very low mortality rate (12%). The high specific intestine weight (7%) and intake rates of biomass and phytoplankton by silver carp (616 g kg-1 of fish day-1 and 1.6 x 1011 cell kg-1 of fish day-1, respectively) demonstrated the importance of the feeding activity of the fish. Zooplankton intake rates were lower (2 x 107 bodies kg-1 of fish day-1). The high intestine index (3 to 4.3 for fish sizes of 14 to 22 cm) and the dominance of phytoplankton in the gut contents (99.95%) confirmed an omnivorous/ phytoplanctivorous diet. Silver carp were efficient in removing plankton from the HRPTS effluent. The net removal yields of biomass were 285 g m-3 day-1 and 322 g kg-1 of fish day-1, 7 x 1010 algal cells kg-1 of fish day-1 and 8.7 x 107 zooplankton bodies kg-1 of fish day-1, with net removal rates of 47, 64 and 62%, respectively. The total suspended solids concentration decreased from 211 in the inflow to 112 mg L-1 in the fish pond.


1995 ◽  
Vol 31 (10) ◽  
pp. 29-40 ◽  
Author(s):  
J. E. Thorpe ◽  
C. Young Cho

Most species in aquaculture are new to cultivation and so behave like wild animals. They are products of evolution, with adaptations to specific habitat conditions. In the wild, food is not available uniformly throughout the day or the year, or in space, and rarely exceeds the fishes needs. Competition is energetically expensive, reducing growth efficiency. Consequently, feeding activity patterns have evolved, implying internal appetite rhythms, which optimise food intake under these various constraints. Salmonids can adapt quickly to short term variation in food availability, but show seasonal genetically determined anorexia. Rational feeding regimes in culture should take all such features into account. When appetite is high naturally, food should be presented so that it is economically indefensible - where every individual can eat, and where fighting does not pay. At periods of anorexia it will be prudent to offer no food. Manufacturers' feed tables are usually regimes devised to meet the bioenergetic needs of fishes, as they are understood in a physico-chemical sense. While useful first approximations, they do not take into account these evolutionary features of the fishes, and can lead to waste. Methods of presentation are described which allow the fish to determine when food shall be available, and in ways which, by diminishing the advantages of social dominance, ensure relatively even opportunities to feed for all individuals in the population. Allowing the fish to set the time-table reduces the likelihood of waste.


Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 701
Author(s):  
Lorenzo Tonina ◽  
Giulia Zanettin ◽  
Paolo Miorelli ◽  
Simone Puppato ◽  
Andrew G. S. Cuthbertson ◽  
...  

The strawberry blossom weevil (SBW), Anthonomus rubi, is a well-documented pest of strawberry. Recently, in strawberry fields of Trento Province (north-east Italy), new noteworthy damage on fruit linked to SBW adults was observed, combined with a prolonged adult activity until the autumn. In this new scenario, we re-investigated SBW biology, ecology, monitoring tools, and potential control methods to develop Integrated Pest Management (IPM) strategies. Several trials were conducted on strawberry in the laboratory, field and semi-natural habitats. The feeding activity of adult SBW results in small deep holes on berries at different stages, causing yield losses of up to 60%. We observed a prolonged survival of newly emerged adults (>240 days) along with their ability to sever flower buds without laying eggs inside them in the same year (one generation per year). SBW adults were present in the strawberry field year-round, with movement between crop and no crop habitats, underlying a potential role of other host/feeding plants to support its populations. Yellow sticky traps combined with synthetic attractants proved promising for both adult monitoring and mass trapping. Regarding control, adhesive tapes and mass trapping using green bucket pheromone traps gave unsatisfactory results, while the high temperatures provided by the black fabric, the periodic removal of severed buds or adults and Chlorpyrifos-methyl application constrained population build-up. The findings are important for the development of an IPM strategy.


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