Susceptibility of the leech Batracobdella picta (Verrill) to Trypanosoma andersoni Reilly and Woo and Trypanosoma grylli Nigrelli (Kinetoplastida)

1982 ◽  
Vol 60 (6) ◽  
pp. 1441-1445 ◽  
Author(s):  
Brian O. Reilly ◽  
P. T. K. Woo
Keyword(s):  
Digestive Tract ◽  
Binary Fission ◽  
Hyla Versicolor ◽  
Infected Blood ◽  
Tree Frogs ◽  
Blood Meals

Laboratory-raised grey tree frogs, Hyla versicolor LeConte, infected with either Trypanosoma andersoni Reilly and Woo or Trypanosoma grylli Nigrelli were fed on by laboratory-raised leeches, Batracobdella picta (Verrill). Trypanosoma andersoni multiplied by binary fission as sphaeromastigotes and epimastigotes in the gut of B. picta at 22 ± 1 °C. Some sphaeromastigotes and epimastigotes contained yellow granules. Two types of metatrypanosomes were found in the digestive tract of the leech at 24 days. Trypanosomes from leeches which had infected blood meals 35 days earlier were not infective when inoculated intraperitoneally or by the leeches feeding on laboratory raised H. versicolor. Trypanosoma grylli did not develop in B. picta at 22 ± 1 °C

scholarly journals Experimental Assessment of Zika Virus Mechanical Transmission by Aedes aegypti

Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 695 ◽  
Author(s):  
Antoine Boullis ◽  
Nadège Cordel ◽  
Cécile Herrmann-Storck ◽  
Anubis Vega-Rúa
Keyword(s):  
Experimental Design ◽  
Aedes Aegypti ◽  
Zika Virus ◽  
Infectious Virus ◽  
Viral Rna ◽  
Mechanical Transmission ◽  
Experimental Assessment ◽  
Infected Blood ◽  
Virus Titration ◽  
Blood Meals

The pandemic emergence of several mosquito-borne viruses highlights the need to understand the different ways in which they can be transmitted by vectors to human hosts. In this study, we evaluated the propensity of Aedes aegypti to transmit mechanically Zika virus (ZIKV) using an experimental design. Mosquitoes were allowed to feed on ZIKV-infected blood and were then rapidly transferred to feed on ZIKV-free blood until they finished their meal. The uninfected blood meals, the mosquito abdomens, as well as the mouthparts dissected from fully and partially engorged mosquitoes were analyzed using RT-qPCR and/or virus titration. All the fully engorged mosquito abdomens were ZIKV-infected, whereas their mouthparts were all ZIKV-negative. Nonetheless, one of the partially engorged mosquitoes carried infectious particles on mouthparts. No infectious virus was found in the receiver blood meals, while viral RNA was detected in 9% of the samples (2/22). Thus, mechanical transmission of ZIKV may sporadically occur via Ae. aegypti bite. However, as the number of virions detected on mouthparts (2 particles) is not sufficient to induce infection in a naïve host, our results indicate that mechanical transmission does not impact ZIKV epidemiology.

The leech as a vector of a fish piroplasm

1980 ◽  
Vol 58 (9) ◽  
pp. 1631-1637 ◽  
Author(s):  
R. A. Khan
Keyword(s):  
Marine Fish ◽  
Blood Meal ◽  
Gadus Morhua ◽  
Infected Fish ◽  
Binary Fission ◽  
Gut Contents ◽  
Pseudopleuronectes Americanus ◽  
Infected Blood ◽  
Fish Blood ◽  
Anarhichas Lupus

A piroplasm, Haemohormidium beckeri, is redescribed from two marine fish, Lycodes lavalaei and Lycodes vahlii (Zoarcidae). The parasite divided by both binary fission and schizogony. In the latter process, up to eight merozoites were produced and these developed within mature erythrocytes. Infections were prevalent among fish from areas off the Labrador coast. Parasitemias, which varied from light infections to estimates of 60 parasites/1000 erythrocytes, were recorded in 15 fish for about 6 months. Subinoculation of infected blood initiated infections in two perciform fish, Myoxocephalus octodecemspinosus and Anarhichas lupus, but not in a pleuronectiform, Pseudopleuronectes americanus, or a gadiform, Gadus morhua. Natural infections were present in three leeches, Platybdella olriki, that had fed on an infected L. lavalaei. Piroplasms were also observed in the gastrointestinal content of all 94 laboratory-reared leeches, Johanssonia arctica, dissected 7 through 109 days after engorgement on infected fish blood. Inoculations of gut contents from leeches after digestion of a blood meal produced infections in uninfected fish. Natural transmission occurred when leeches were fed again on susceptible fish, whereas pipetting entire leeches into the stomach of fish did not initiate infections. This is the first evidence that leeches transmit piroplasms in nature to fish.

scholarly journals Malaria parasite immune evasion and adaptation to its mosquito host is influenced by the acquisition of multiple blood meals

2019 ◽  
Author(s):  
Hyeogsun Kwon ◽  
Rebekah A. Reynolds ◽  
Maria L. Simões ◽  
George Dimopoulos ◽  
Ryan C. Smith
Keyword(s):  
Blood Meal ◽  
Blood Feeding ◽  
Parasite Development ◽  
Protein Meal ◽  
Infected Blood ◽  
Adult Lifespan ◽  
Multiple Blood ◽  
The Impact ◽  
Immune Detection ◽  
Blood Meals

AbstractA minimum of two blood meals are required for a mosquito to acquire and transmit malaria, yet Anopheles mosquitoes frequently obtain additional blood meals during their adult lifespan. To determine the impact of subsequent blood-feeding on parasite development in Anopheles gambiae, we examined rodent and human Plasmodium parasite infection with or without an additional non-infected blood meal. We find that an additional blood meal significantly reduces P. berghei immature oocyst numbers, yet does not influence mature oocysts that have already begun sporogony. This is in contrast to experiments performed with the human parasite, P. falciparum, where an additional blood meal does not affect oocyst numbers. These observations are reproduced when mosquitoes were similarly challenged with an artificial protein meal, suggesting that parasite losses are due to the physical distension of the mosquito midgut. We provide evidence that feeding compromises the integrity of the midgut basal lamina, enabling the recognition and lysis of immature P. berghei oocysts by the mosquito complement system. Moreover, we demonstrate that additional feeding promotes P. falciparum oocyst growth, suggesting that human malaria parasites exploit host resources provided with blood-feeding to accelerate their growth. This contrasts experiments with P. berghei, where the size of surviving oocysts is independent of an additional blood meal. Together, these data demonstrate differences in the ability of Plasmodium species to evade immune detection and adapt to utilize host resources at the oocyst stage, representing an additional, yet unexplored component of vectorial capacity that has important implications for transmission of malaria.

scholarly journals Parallel changes in mate-attracting calls and female preferences in autotriploid tree frogs

2011 ◽  
Vol 279 (1733) ◽  
pp. 1583-1587 ◽  
Author(s):  
Mitch A. Tucker ◽  
H. C. Gerhardt
Keyword(s):  
Pulse Rate ◽  
Parental Species ◽  
Diploid Species ◽  
Sympatric Speciation ◽  
Hyla Versicolor ◽  
Hyla Chrysoscelis ◽  
Female Preferences ◽  
The Mean ◽  
Tree Frogs ◽  
Different Origins

For polyploid species to persist, they must be reproductively isolated from their diploid parental species, which coexist at the same time and place at least initially. In a complex of biparentally reproducing tetraploid and diploid tree frogs in North America, selective phonotaxis—mediated by differences in the pulse-repetition (pulse rate) of their mate-attracting vocalizations—ensures assortative mating. We show that artificially produced autotriploid females of the diploid species ( Hyla chrysoscelis ) show a shift in pulse-rate preference in the direction of the pulse rate produced by males of the tetraploid species ( Hyla versicolor ). The estimated preference function is centred near the mean pulse rate of the calls of artificially produced male autotriploids. Such a parallel shift, which is caused by polyploidy per se and whose magnitude is expected to be greater in autotetraploids, may have facilitated sympatric speciation by promoting reproductive isolation of the initially formed polyploids from their diploid parental forms. This process also helps to explain why tetraploid lineages with different origins have similar advertisement calls and freely interbreed.

The life cycle of Trypanosoma murmanensis Nikitin

1976 ◽  
Vol 54 (11) ◽  
pp. 1840-1849 ◽  
Author(s):  
R. A. Khan
Keyword(s):  
Life Cycle ◽  
Digestive Tract ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Maximum Size ◽  
Yellow Pigment ◽  
Infected Blood ◽  
Parasitic Copepods ◽  
Average Maximum

Trypanosoma murmanensis from the blood of the Atlantic cod, Gadus morhua, undergoes multiplicative development in the digestive tract of a marine leech Johanssonia sp. as the amastigote and sphaeromastigote stages. Epimastigotes, which apparently do not divide, migrate later to the proboscis of the leech and subsequently transform to metatrypomastigotes that are transmitted during engorgement. Fine granules of yellow pigment, observed in all stages, eventually disappear in the metatrypomastigotes. The cycle in the leech is completed in 62 days at 0–1 °C but is more rapid (42 days) at 4–6 °C. Cod-fed infected leeches remained aparasitemic. Trypomastigotes did not develop in two species of parasitic copepods, Lerneocera branchialis and Clavella adunca.Small, slender trypomastigotes, which appear from 3 days after infection, grow into larger forms that subsequently acquire myonemes. The average maximum size occurs about 55 days after infection. There is always a range of sizes, which becomes more apparent as the parasitemia declines from about 29 days. Parasitemias vary from 105 per millilitre to numbers too few to estimate accurately. No divisional forms were observed in cod and increased parasitemias do not apparently occur after inoculations of infected blood.

Comparative morphology of the digestive tract of two Neotropical tree frogs (Genus Boana)

2019 ◽  
Vol 281 ◽  
pp. 44-52 ◽  
Author(s):  
Bruno S.L. Valverde ◽  
Lara Zácari Fanali ◽  
Lilian Franco-Belussi ◽  
Classius de Oliveira
Keyword(s):  
Digestive Tract ◽  
Comparative Morphology ◽  
Neotropical Tree ◽  
Tree Frogs

Developmental abnormalities in triploid hybrids between tetraploid and diploid tree frogs (genus Hyla)

1992 ◽  
Vol 70 (10) ◽  
pp. 2072-2076
Author(s):  
Barbara K. Mable ◽  
Leslie A. Rye
Keyword(s):  
Parental Species ◽  
Eye Development ◽  
Developmental Differences ◽  
Hyla Versicolor ◽  
Diploid Males ◽  
Cross Combination ◽  
Hyla Cinerea ◽  
Developmental Abnormalities ◽  
Tree Frogs ◽  
Eye Formation

Crosses between tetraploid female grey tree frogs, Hyla versicolor, and diploid males of the same genus may provide information on developmental differences between the parental species. Crosses with Hyla cinerea males in 1988 produced a large number of vigorous offspring, but abnormalities in eye development indicated some incompatibility of the parental genomes. The degree of eye development of the hybrids varied, ranging from completely absent to fully functional. Repetition of this cross combination in 1989 resulted in similar variation in eye formation. Histological sections through developing eyes indicated that the abnormalities may be related to improper formation of the cornea, improper orientation of the lens, or lack of lens induction. This may reflect differences in the timing of development between the two parental species.

scholarly journals The Extrinsic Incubation Period of Zika Virus in Florida Mosquitoes Aedes aegypti and Ae. albopictus

Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1252
Author(s):  
Rebecca A. Zimler ◽  
Barry W. Alto
Keyword(s):  
Aedes Aegypti ◽  
Incubation Period ◽  
Health Risks ◽  
Zika Virus ◽  
Mosquito Vectors ◽  
Zikv Infection ◽  
Infected Blood ◽  
Extrinsic Incubation Period ◽  
Asian Lineage ◽  
Blood Meals

The Asian genotype of Zika virus (ZIKV) emerged in Brazil in 2015 and subsequently spread throughout the Americas. In July 2016, Florida experienced its first locally acquired ZIKV infection in the continental U.S. Concerns about health risks from ZIKV infection have increased the need to investigate the interactions between potential mosquito vectors and ZIKV. The time it takes for an arbovirus to propagate within a mosquito, and become transmissible, is the extrinsic incubation period (EIP). The EIP for potential mosquito vectors in Florida is unknown. To address this gap in the understanding of ZIKV epidemiology, Florida Aedes aegypti (L.) and Ae. albopictus (Skuse) were orally exposed to ZIKV infected blood meals and fully engorged mosquitoes were held at a constant temperature of 28 °C through the duration of the experiment. Saliva expectorates were collected from cohorts of mosquitoes and tested for the presence of ZIKV at three-day intervals over a period of 24 days to allow for an evaluation of the EIP of the emergent Asian lineage of ZIKV. High rates of infected bodies in Ae. albopictus (75–94%) and Ae. aegypti (68–86%) were observed throughout the incubation period, which did not differ by species. Higher rates of disseminated infection were observed later during the incubation period but did not differ between species. We calculated the 50% EIP to be shorter in Ae. albopictus than Ae. aegypti (16.2 and 18.2 days post infection, respectively). The competence for ZIKV observed in both species may contribute to high rates of ZIKV transmission in Florida populations.

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