scholarly journals Assessment of Associations between Malaria Parasites and Avian Hosts—A Combination of Classic System and Modern Molecular Approach

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 636
Author(s):  
Xi Huang

Avian malaria and related haemosporidian parasites are responsible for fitness loss and mortality in susceptible bird species. This group of globally distributed parasites has long been used as a classical system for investigating host–parasite associations. The association between a parasite and its hosts can be assessed by the prevalence in the host population and infection intensity in a host individual, which, respectively, reflect the ability of the parasite to infect the host and reproduce within the host. However, the latter has long been poorly investigated due to numerous challenges, such as lack of general molecular markers and limited sensitivity of traditional methods, especially when analysing naturally infected birds. The recent development of genetic databases, together with novel molecular methodologies, has shed light on this long-standing problem. Real-time quantitative PCR has enabled more accurate quantification of avian haemosporidian parasites, and digital droplet PCR further improved experimental sensitivity and repeatability of quantification. In recent decades, parallel studies have been carried out all over the world, providing great opportunities for exploring the adaptation of haemosporidian parasites to different hosts and the variations across time and space, and further investigating the coevolutionary history between parasites and their hosts. I hereby review the most important milestones in diagnosis techniques of avian haemosporidian parasites and illustrate how they provide new insights for understanding host–parasite associations.

2021 ◽  
Author(s):  
Luz Garcia-Longoria ◽  
Jaime Muriel ◽  
Sergio Magallanes ◽  
Zaira Hellen Villa-Galarce ◽  
Leonila Ricopa ◽  
...  

Abstract Characterizing the diversity and structure of host-parasite communities is crucial to understanding their eco-evolutionary dynamics. Malaria and related haemosporidian parasites are responsible for fitness loss and mortality in bird species worldwide. However, despite exhibiting the greatest ornithological biodiversity, avian haemosporidians from Neotropical regions are quite unexplored. Here, we analyse the genetic diversity of bird haemosporidian parasites (Plasmodium and Haemoproteus) in 1,336 individuals belonging to 206 bird species to explore for differences in diversity of parasite lineages and bird species across five well-differentiated Peruvian ecoregions. We detected 70 different haemosporidian lineages infecting 74 bird species. We showed that 25 out of the 70 haplotypes had not been previously recorded. Moreover, we also identified 81 new host – parasite interactions representing new host records for these haemosporidian parasites. Our outcomes revealed that the effective diversity (as well as the richness, abundance, and Shannon-Weaver index) for both birds and parasite lineages was higher in Amazon basin ecoregions. Furthermore, we also showed that ecoregions with greater diversity of bird species also had high parasite richness, hence suggesting that host community is crucial in explaining parasite richness. Generalist parasites were found in ecoregions with lower bird diversity, implying that the abundance and richness of hosts may shape the exploitation strategy followed by haemosporidian parasites. These outcomes reveal that Neotropical region is a major reservoir of unidentified haemosporidian lineages. Further studies analysing host distribution and specificity of these parasites in the tropics will provide important knowledge about phylogenetic relationships, phylogeography, and patterns of evolution and distribution of haemosporidian parasites.


Parasitology ◽  
2009 ◽  
Vol 136 (10) ◽  
pp. 1121-1131 ◽  
Author(s):  
L. MARIA ◽  
E. SVENSSON ◽  
ROBERT E. RICKLEFS

SUMMARYCommon bird species were screened during May and June 2007 on Barbados for haemosporidian parasites (Haemosporida) of the genera Haemoproteus and Plasmodium to determine whether the low parasite diversity reported in previous studies might have reflected limited sampling. PCR screening and DNA sequencing revealed a single predominant lineage of Haemoproteus identified as H. coatneyi. Sixty-two out of 257 birds were infected with Haemoproteus spp. on Barbados in 2007. Fifty-nine of the infections were identified as H. coatneyi (lineage HC), the only lineage recovered in the previous study in 1993. Two of the infections recovered from the bananaquit (Coereba flaveola) were identified as Haemoproteus spp. (lineage HD), which is the prevalent haemosporidian parasite in C. flaveola on Grenada. We discuss the possibility of infrequent colonization events and absence of vectors as explanations for Barbados's low avian haemosporidian diversity. In our study, the parasites were absent from the southeast of the island, whereas they were abundant in several host species in the northwest. Accordingly, environmental and host population genetic differences were also investigated between the areas with and without parasites. No host genetic differences were found between the parasite-free and the parasite-afflicted regions. However, the parasite-free region is slightly warmer and drier, and it supports less vegetation than the parasite-afflicted region. The influence that this harsher environment may have on vector survival is discussed.


Author(s):  
Yvonne R. Schumm ◽  
Dimitris Bakaloudis ◽  
Christos Barboutis ◽  
Jacopo G. Cecere ◽  
Cyril Eraud ◽  
...  

AbstractDiseases can play a role in species decline. Among them, haemosporidian parasites, vector-transmitted protozoan parasites, are known to constitute a risk for different avian species. However, the magnitude of haemosporidian infection in wild columbiform birds, including strongly decreasing European turtle doves, is largely unknown. We examined the prevalence and diversity of haemosporidian parasites Plasmodium, Leucocytozoon and subgenera Haemoproteus and Parahaemoproteus in six species of the order Columbiformes during breeding season and migration by applying nested PCR, one-step multiplex PCR assay and microscopy. We detected infections in 109 of the 259 screened individuals (42%), including 15 distinct haemosporidian mitochondrial cytochrome b lineages, representing five H. (Haemoproteus), two H. (Parahaemoproteus), five Leucocytozoon and three Plasmodium lineages. Five of these lineages have never been described before. We discriminated between single and mixed infections and determined host species-specific prevalence for each parasite genus. Observed differences among sampled host species are discussed with reference to behavioural characteristics, including nesting and migration strategy. Our results support previous suggestions that migratory birds have a higher prevalence and diversity of blood parasites than resident or short-distance migratory species. A phylogenetic reconstruction provided evidence for H. (Haemoproteus) as well as H. (Parahaemoproteus) infections in columbiform birds. Based on microscopic examination, we quantified parasitemia, indicating the probability of negative effects on the host. This study provides a large-scale baseline description of haemosporidian infections of wild birds belonging to the order Columbiformes sampled in the northern hemisphere. The results enable the monitoring of future changes in parasite transmission areas, distribution and diversity associated with global change, posing a potential risk for declining avian species as the European turtle dove.


2008 ◽  
Vol 68 (3) ◽  
pp. 611-615 ◽  
Author(s):  
LA. Anjos ◽  
WO. Almeida ◽  
A. Vasconcellos ◽  
EMX. Freire ◽  
CFD. Rocha

From January to April 2006, 37 specimens of Hemidactylus mabouia were collected in houses, in the municipality of Barbalha (7° 20' S and 39° 18' W), Ceará State, Northeast Brazil. Among the individuals captured, 17 were infected with pentastomids, totalling a prevalence of 45.9%, which did not differ between sexes. Host size did not influence the infection intensity. Two species of pentastomids were found: Raillietiella frenatus and R. mottae. The prevalence of R. frenatus (43.2%) was higher than R. mottae (2.7%), whereas the infection intensity of R. frenatus was comparatively lower (1.8 ± 1.4) than R. mottae (36 parasites in a single host). Overall mean intensity of infection was 3.8 ± 8.4 pentastomids. We found no pentastomid infecting juvenile geckos. The parameters of infection in this host population are in accordance to the findings of other studies, in which the high parasitism rate was associated to the feeding habits of geckos living in houses and buildings. Hemidactylus mabouia is a new host to R. mottae and the infection by R. frenatus is the first record of the occurrence this pentastomid species in Brazil.


Parasitology ◽  
1974 ◽  
Vol 68 (2) ◽  
pp. 271-284 ◽  
Author(s):  
A. E. Rumpus ◽  
C. R. Kennedy

The respiration rates of individual Gammarus pulex infected by larval Pomphorhynchus laevis were investigated with particular reference to the stage of development of the host and parasite and to the water temperature. At 20°C the oxygen consumption of Gammarus of all sizes was reduced by an average of 19·3 % by the presence of cystacanths of the parasite, but was unaffected by the presence of acanthellae. It is considered that the small size of this larval stage, in relation to that of its host, is responsible for the failure to detect an effect. Multiple infections did not exert any greater effect upon host respiration than single cystacanths, nor did it appear that the parasite had different effects upon hosts of different sexes. At 10°C no significant differences were observed between the respiration rates of infected and uninfected gammarids. The parasite was probably still depressing the host respiration rate at this temperature, but the oxygen uptake of G. pulex is so low that the differences between infected and uninfected individuals were too small to be detected. The parasite has a direct effect upon the physiological processes of the host, but neither the mechanism of this nor the reasons for the different effects found in different host-parasite systems are yet understood. Despite the pronounced effect of P. laevis on respiration of individual hosts, its effect upon the oxygen consumption of a natural host population is small since only a small proportion of the population carries infections and water temperatures remain below 10°C for over half the year.


2001 ◽  
Vol 79 (4) ◽  
pp. 554-561 ◽  
Author(s):  
Shawn Meagher ◽  
Timothy P O'Connor

The effects of parasites on their hosts can vary among host populations, but few studies have examined geographic variation in host-parasite interactions. We examined the effects of Capillaria hepatica (Nematoda) infection on deer mice (Peromyscus maniculatus gracilis) from two different populations. Specifically, we measured the basal metabolic rate (BMR), cold-stress maximum oxygen consumption (MRpeak), metabolic scope (MRpeak/BMR), and thermogenic endurance of infected and uninfected mice from one population with, and a second population without, a history with C. hepatica. Infection had no effect on BMR, but did have effects on cold-stress measures. A previous study documented a significant relationship between survival and MRpeak in wild deer mice; hence, the effects of infection on the parameters that we measured could influence fitness. Only mice that had no historical association with C. hepatica displayed negative consequences of infection, which suggests that the historical host population has evolved mechanisms to cope with infection. Models of the evolution of virulence should include evolutionary responses of both hosts and parasites, particularly when systems involve macroparasites that have long generation times.


Parasitology ◽  
2004 ◽  
Vol 130 (2) ◽  
pp. 169-176 ◽  
Author(s):  
M. BANDILLA ◽  
T. HAKALAHTI ◽  
P. J. HUDSON ◽  
E. T. VALTONEN

By sampling individual rainbow trout, Oncorhynchus mykiss, at a fish farm we showed that Argulus coregoni were aggregated within their host population. The relative significance of susceptibility and exposure generating the observed pattern was tested using experimental infections. We examined, whether rainbow trout developed protective resistance mechanisms against the louse following a challenge infection and if there was variation between individual trout in their susceptibility to A. coregoni metanauplii. Fish were exposed to 20 A. coregoni for 5, 25, 50, 85 or 120 min and the numbers attaching recorded. Three weeks later, developing argulids were removed and the experiment repeated with a standardized exposure of 20 metanauplii. Prior exposure of fish with A. coregoni did not reduce the total infection intensity compared to naïve fish, but fish gained infection more rapidly. We suggest that there is no protective acquired resistance of pre-exposed rainbow trout to subsequent Argulus exposure. The possibility that an immunosuppressive mechanism by argulids was acting enabling the higher attachment rate could be refuted since control individuals, not previously exposed to lice, gained the infection at a similar rate as the fish challenged twice. Our results do not indicate clear differences in susceptibility among individual fish but the transmission of metanauplii on fish seemed to be opportunistic and non-selective. Our results support the view that variation in exposure time, rather than differences in susceptibility of individual hosts, might be the key factor in generating the aggregated distribution of Argulus on their hosts.


2020 ◽  
Author(s):  
Nayden Chakarov ◽  
Helge Kampen ◽  
Anja Wiegmann ◽  
Doreen Werner ◽  
Staffan Bensch

Abstract Background: The behaviour of blood-sucking arthropods is a crucial determinant of blood protozoan distribution and hence of host-parasite coevolution, but it is very challenging to study in the wild. The molecular identification of parasite lineages in vectors can be a useful key to understand the behaviour and transmission patterns realised by these vectors. Methods: In this study, we collected blackflies around nests of three raptor species in the upper forest canopy in central Europe and examined the presence of vertebrate DNA and haemosporidian parasites in them. We molecularly analysed 156 blackfly individuals, their vertebrate blood meals, and the haemosporidian parasite lineages they carried. Results: We identified nine species of Simulium blackflies, largely belonging to the subgenera Nevermannia and Eusimulium. Only 1% of the collected specimens was visibly engorged, and only 4% contained remains of host DNA. However, in 29% of the blackflies Leucocytozoon lineages were identified, which is evidence of a previous blood meal on an avian host. Based on the known vertebrate hosts of the recorded Leucocytozoon lineages, we can infer that large and/or abundant birds, such as thrushes, crows, pigeons, birds of prey, owls and tits are the main targets of ornithophilic blackflies in the canopy. Blackfly species contained similar proportions of host group-specific parasite lineages and thus do not appear to be associated with particular host groups. Conclusions: The Leucocytozoon clade infecting thrushes, crows, and pigeons present in most represented blackfly species suggests a lack of association between hosts and blackflies, which can increase the probability of host switches of blood parasites. However, the composition of the simuliid species differed between nests of common buzzards, goshawks and red kites. This segregation can be explained by coinciding habitat preferences between host and vector, and may lead to the fast speciation of Leucocytozoon parasites. Thus, subtle ecological preferences and lack of host preference of vectors in the canopy may enable both parasite diversification and host switches, and enforce a habitat-dependent evolution of avian malaria parasites and related haemosporidia.


2018 ◽  
Vol 373 (1745) ◽  
pp. 20170101 ◽  
Author(s):  
David J. Civitello ◽  
Brent E. Allman ◽  
Connor Morozumi ◽  
Jason R. Rohr

Anthropogenic resource supplementation can shape wildlife disease directly by altering the traits and densities of hosts and parasites or indirectly by stimulating prey, competitor or predator species. We first assess the direct epidemiological consequences of supplementation, highlighting the similarities and differences between food provisioning and two widespread forms of nutrient input: agricultural fertilization and aquatic nutrient enrichment. We then review an aquatic disease system and a general model to assess whether predator and competitor species can enhance or overturn the direct effects of enrichment. All forms of supplementation can directly affect epidemics by increasing host population size or altering parasite production within hosts, but food provisioning is most likely to aggregate hosts and increase parasite transmission. However, if predators or competitors increase in response to supplementation, they could alter resource-fuelled outbreaks in focal hosts. We recommend identifying the traits of hosts, parasites or interacting species that best predict epidemiological responses to supplementation and evaluating the relative importance of these direct and indirect mechanisms. Theory and experiments should examine the timing of behavioural, physiological and demographic changes for realistic, variable scenarios of supplementation. A more integrative view of resource supplementation and wildlife disease could yield broadly applicable disease management strategies. This article is part of the theme issue ‘Anthropogenic resource subsidies and host–parasite dynamics in wildlife’.


2009 ◽  
Vol 46 (3) ◽  
pp. 162-167 ◽  
Author(s):  
S. Guagliardo ◽  
D. Tanzola ◽  
C. Schwerdt ◽  
N. Galeano

AbstractLarvae of tetraphyllidean cestodes have been recorded in several species of marine teleosts. However, little is known on parasite-host interactions. In view of this, the present study aims at i) determining the localization sites of a larval type, belonging to the Scolex group, in the digestive tract mucose; ii) describing the anatomo-pathological features of the larval lesions produced; and iii) evaluating the potential effect of parasite intensity on the body condition of the host. Our findings reveal that parasitic charges were more intense in the second portion of the digestive tract. In the area of contact between the parasite and the epithelium a compressive atrophy of the cells was observed with a marked lowering and disappearance of the epithelial layer. The condition factor of the samples analyzed was significantly affected by infection intensity, thus revealing an adverse effect on the growth and physical condition of the host.


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