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21 pages, 3203 KiB

Open AccessArticle

Identification of Putative Neuropeptides That Alter the Behaviour of Schistosoma mansoni Cercariae

by Conor E. Fogarty, Saowaros Suwansa-ard, Phong Phan, Donald P. McManus, Mary G. Duke, Russell C. Wyeth, Scott F. Cummins and Tianfang Wang

Biology 2022, 11(9), 1344; https://doi.org/10.3390/biology11091344 - 12 Sep 2022

Cited by 1 | Viewed by 2008

Abstract

Elucidating the infectivity of Schistosoma mansoni, one of the main etiological agents of human schistosomiasis, requires an improved understanding of the behavioural mechanisms of cercariae, the non-feeding mammalian infective stage. This study investigated the presence and effect of cercariae-derived putative neuropeptides on [...] Read more.

Elucidating the infectivity of Schistosoma mansoni, one of the main etiological agents of human schistosomiasis, requires an improved understanding of the behavioural mechanisms of cercariae, the non-feeding mammalian infective stage. This study investigated the presence and effect of cercariae-derived putative neuropeptides on cercarial behaviour when applied externally. Cercariae were peptidomically analysed and 11 neuropeptide precursor proteins, all of which were specific to the Schistosoma genus and most of which highly expressed in the cercarial stage, were identified in cercariae for the first time. Protein–protein interaction analysis predicted the interaction of various neuropeptide precursors (e.g., Sm-npp-30, Sm-npp-33, Sm-npp-35) with cercarial structural proteins (e.g., myosin heavy chain and titin). In total, nine putative neuropeptides, selected based on their high hydrophobicity and small size (~1 kilodalton), were tested on cercariae (3 mg/mL) in acute exposure (1 min) and prolonged exposure (360 min) behavioural bioassays. The peptides AAYMDLPW-NH₂, NRKIDQSFYSYY-NH₂, FLLALPSP-OH, and NYLWDTRL-NH₂ stimulated acute increases in cercarial spinning, stopping, and directional change during active states. However, only NRKIDQSFYSYY-NH₂ caused the same behavioural changes at a lower concentration (0.1 mg/mL). After prolonged exposure, AAYMDLPW-NH₂ and NYLWDTRL-NH₂ caused increasing passive behaviour and NRKIDQSFYSYY-NH₂ caused increasing body-first and head-pulling movements. These findings characterise behaviour-altering novel putative neuropeptides, which may inform future biocontrol innovations to prevent human schistosomiasis. Full article

(This article belongs to the Special Issue Host-Parasite Interactions: Trends in Molecular Ecology)

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11 pages, 1588 KiB

Open AccessArticle

Morphological and Molecular Description of Sarcocystis myodes n. sp. from the Bank Vole (Clethrionomys glareolus) in Lithuania

by Eglė Rudaitytė-Lukošienė, Marius Jasiulionis, Linas Balčiauskas, Petras Prakas, Vitalijus Stirkė and Dalius Butkauskas

Biology 2022, 11(4), 512; https://doi.org/10.3390/biology11040512 - 26 Mar 2022

Cited by 4 | Viewed by 1760

Abstract

Numerous rodent species have been broadly examined for Sarcocystis parasites. Nevertheless, recent investigations on Sarcocystis spp. in voles are lacking. As many as 45 bank voles (Clethrionomys glareolus) captured in several locations in Lithuania were examined in the present study. [...] Read more.

Numerous rodent species have been broadly examined for Sarcocystis parasites. Nevertheless, recent investigations on Sarcocystis spp. in voles are lacking. As many as 45 bank voles (Clethrionomys glareolus) captured in several locations in Lithuania were examined in the present study. Based on morphological, genetic, and phylogenetic results, sarcocysts detected in one bank vole were described as Sarcocystis myodes n. sp. Using light microscopy analysis, the observed sarcocysts were ribbon-shaped, 6000–3000 × 70–220 µm in size. Sarcocysts were characterized by a relatively thin (about 1 μm) and apparently smooth cyst wall. The lancet-shaped bradyzoites were 9.6–12.0 × 3.1–4.6 μm in size. By transmission electron microscopy, the sarcocyst wall was up to 1 μm thick, parasitophorous vacuolar membrane had small knob-like blebs. Based on 18S rDNA, 28S rDNA, cox1, rpoB, and ITS1 loci, S. myodes showed highest similarity with S. ratti from the black rat (Rattus rattus). According to phylogenetic placement, S. myodes was most closely related to Sarcocystis spp. that employ predatory mammals as their definitive hosts. Morphologically, sarcocysts of S. myodes have similar features to those of S. cernae, S. dirumpens, and S. montanaensis described in voles, however, they use birds of prey or snakes as their definitive hosts. Full article

(This article belongs to the Special Issue Host-Parasite Interactions: Trends in Molecular Ecology)

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13 pages, 1387 KiB

Open AccessArticle

Evaluation of Clove Extract for Drug Therapy of Ciliate Infection in Coral (Goniopora columna)

by Tah-Wei Chu, Chiu-Min Cheng, Yu-Rong Cheng, Cheng-Di Dong, Chih-Hung Chuang, Chih-Hung Pan, Wei-Ting Sun and De-Sing Ding

Biology 2022, 11(2), 280; https://doi.org/10.3390/biology11020280 - 10 Feb 2022

Cited by 3 | Viewed by 2520

Abstract

In recent years, ciliate infections have caused serious casualties to corals in the ocean. Infected corals die within a short period of time, which not only poses a threat to wild coral reefs, but also has a major impact on large scale aquaculture [...] Read more.

In recent years, ciliate infections have caused serious casualties to corals in the ocean. Infected corals die within a short period of time, which not only poses a threat to wild coral reefs, but also has a major impact on large scale aquaculture of coral. Clove is a kind of Chinese medicine with antifungal, antibacterial, antiviral, insecticidal, and other functions. Clove is a natural product. If it can be used in the treatment of coral ciliates, it will reduce this threat to the environment. The clove extract was diluted with sterile seawater to 500 ppm, 1500 ppm, 2500 ppm, 5000 ppm, 7500 ppm, and 10,000 ppm to carry out virulence test on ciliates. The results show that the LC₅₀ value is 1500 ppm, which can cause the death of ciliates in 10 min without causing significant changes in G. columna SOD, CAT, chlorophyll a, and zooxanthellae. In addition, observation of tissue slices revealed that no ciliates and vacuum were found in the G. columna tissue after 10 min of medicated bathing. In summary, 1500 ppm of clove extract can be used for the treatment of coral ciliates. Full article

(This article belongs to the Special Issue Host-Parasite Interactions: Trends in Molecular Ecology)

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13 pages, 1313 KiB

Open AccessArticle

Effects of Ciliate Infection on the Activities of Two Antioxidant Enzymes (SOD and CAT) in Captive Coral (Goniopora columna) and Evaluation of Drug Therapy

by Chiu-Min Cheng, Yu-Rong Cheng, De-Sing Ding, Ya-Ting Chen, Wei-Ting Sun and Chih-Hung Pan

Biology 2021, 10(11), 1216; https://doi.org/10.3390/biology10111216 - 21 Nov 2021

Cited by 8 | Viewed by 2989

Abstract

Ciliate infection is a serious parasitic disease of coral. Infected coral rots and dies in a short time. In addition to killing corals by infecting them in the oceans, ciliate infection also poses a threat to corals farmed on a large scale. In [...] Read more.

Ciliate infection is a serious parasitic disease of coral. Infected coral rots and dies in a short time. In addition to killing corals by infecting them in the oceans, ciliate infection also poses a threat to corals farmed on a large scale. In this study, two antioxidant enzymes (SOD and CAT) were used to judge the stress response in Goniopora columna after infection, and KCl and H₂O₂ were used to evaluate the therapeutic effect. The results showed that SOD and CAT increased during the early stage of infection but decreased with the extension of infection time. In terms of drug therapy, it was found that the treatment of ciliate infection with 1.5% of KCl had no significant effect on SOD and CAT of G. columna. The morphological changes of zooxanthellae, chlorophyll a, and coral were not significant. H₂O₂ leads to a stress response and polyp contraction. In conclusion, 1.5% of KCl can be used in the selection of drugs to treat ciliate infection. Full article

(This article belongs to the Special Issue Host-Parasite Interactions: Trends in Molecular Ecology)

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24 pages, 29369 KiB

Open AccessArticle

Contrasting Host-Parasite Population Structure: Morphology and Mitogenomics of a Parasitic Flatworm on Pelagic Deepwater Cichlid Fishes from Lake Tanganyika

by Nikol Kmentová, Christoph Hahn, Stephan Koblmüller, Holger Zimmermann, Jiří Vorel, Tom Artois, Milan Gelnar and Maarten P. M. Vanhove

Biology 2021, 10(8), 797; https://doi.org/10.3390/biology10080797 - 18 Aug 2021

Cited by 8 | Viewed by 3570

Abstract

Little phylogeographic structure is presumed for highly mobile species in pelagic zones. Lake Tanganyika is a unique ecosystem with a speciose and largely endemic fauna famous for its remarkable evolutionary history. In bathybatine cichlid fishes, the pattern of lake-wide population differentiation differs among [...] Read more.

Little phylogeographic structure is presumed for highly mobile species in pelagic zones. Lake Tanganyika is a unique ecosystem with a speciose and largely endemic fauna famous for its remarkable evolutionary history. In bathybatine cichlid fishes, the pattern of lake-wide population differentiation differs among species. We assessed the congruence between the phylogeographic structure of bathybatine cichlids and their parasitic flatworm Cichlidogyrus casuarinus to test the magnifying glass hypothesis. Additionally, we evaluated the use of a PoolSeq approach to study intraspecific variation in dactylogyrid monogeneans. The lake-wide population structure of C. casuarinus ex Hemibates stenosoma was assessed based on a portion of the cox1 gene combined with morphological characterisation. Additionally, intraspecific mitogenomic variation among 80 parasite samples from one spatially constrained metapopulation was assessed using shotgun NGS. While no clear geographic genetic structure was detected in parasites, both geographic and host-related phenotypic variation was apparent. The incongruence with the genetic north-south gradient observed in H. stenosoma may be explained by the broad host range of this flatworm including eupelagic bathybatine host species that form panmictic populations across the lake. In addition, we present the first parasite mitogenome from Lake Tanganyika and propose a methodological framework for studying the intraspecific mitogenomic variation of dactylogyrid monogeneans. Full article

(This article belongs to the Special Issue Host-Parasite Interactions: Trends in Molecular Ecology)

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20 pages, 4023 KiB

Open AccessArticle

The Inquiline Ant Myrmica karavajevi Uses Both Chemical and Vibroacoustic Deception Mechanisms to Integrate into Its Host Colonies

by Luca Pietro Casacci, Francesca Barbero, Piotr Ślipiński and Magdalena Witek

Biology 2021, 10(7), 654; https://doi.org/10.3390/biology10070654 - 12 Jul 2021

Cited by 9 | Viewed by 3587

Abstract

Social parasitism represents a particular type of agonistic interaction in which a parasite exploits an entire society instead of a single organism. One fascinating form of social parasitism in ants is the “inquilinism”, in which a typically worker-less parasitic queen coexists with the [...] Read more.

Social parasitism represents a particular type of agonistic interaction in which a parasite exploits an entire society instead of a single organism. One fascinating form of social parasitism in ants is the “inquilinism”, in which a typically worker-less parasitic queen coexists with the resident queen in the host colony and produces sexual offspring. To bypass the recognition system of host colonies, inquilines have evolved a repertoire of deceiving strategies. We tested the level of integration of the inquiline Myrmica karavajevi within the host colonies of M. scabrinodis and we investigated the mechanisms of chemical and vibroacoustic deception used by the parasite. M. karavajevi is integrated into the ant colony to such an extent that, in rescue experiments, the parasite pupae were saved prior to the host’s brood. M. karavajevi gynes perfectly imitated the cuticular hydrocarbon profiles of M. scabrinodis queens and the parasite vibroacoustic signals resembled those emitted by the host queens eliciting the same levels of attention in the host workers during playback experiments. Our results suggest that M. karavajevi has evolved ultimate deception strategies to reach the highest social status in the colony hierarchy, encouraging the use of a combined molecular and behavioural approach when studying host–parasite interactions. Full article

(This article belongs to the Special Issue Host-Parasite Interactions: Trends in Molecular Ecology)

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Review

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14 pages, 2383 KiB

Open AccessReview

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

by Xi Huang

Biology 2021, 10(7), 636; https://doi.org/10.3390/biology10070636 - 09 Jul 2021

Cited by 3 | Viewed by 2430

Abstract

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 [...] Read more.

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. Full article

(This article belongs to the Special Issue Host-Parasite Interactions: Trends in Molecular Ecology)

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15 pages, 1375 KiB

Open AccessReview

Reproduction in Trypanosomatids: Past and Present

by Camino Gutiérrez-Corbo, Bárbara Domínguez-Asenjo, María Martínez-Valladares, Yolanda Pérez-Pertejo, Carlos García-Estrada, Rafael Balaña-Fouce and Rosa M. Reguera

Biology 2021, 10(6), 471; https://doi.org/10.3390/biology10060471 - 27 May 2021

Cited by 6 | Viewed by 2967

Abstract

Diseases caused by trypanosomatids (Sleeping sickness, Chagas disease, and leishmaniasis) are a serious public health concern in low-income endemic countries. These diseases are produced by single-celled parasites with a diploid genome (although aneuploidy is frequent) organized in pairs of non-condensable chromosomes. To explain [...] Read more.

Diseases caused by trypanosomatids (Sleeping sickness, Chagas disease, and leishmaniasis) are a serious public health concern in low-income endemic countries. These diseases are produced by single-celled parasites with a diploid genome (although aneuploidy is frequent) organized in pairs of non-condensable chromosomes. To explain the way they reproduce through the analysis of natural populations, the theory of strict clonal propagation of these microorganisms was taken as a rule at the beginning of the studies, since it partially justified their genomic stability. However, numerous experimental works provide evidence of sexual reproduction, thus explaining certain naturally occurring events that link the number of meiosis per mitosis and the frequency of mating. Recent techniques have demonstrated genetic exchange between individuals of the same species under laboratory conditions, as well as the expression of meiosis specific genes. The current debate focuses on the frequency of genomic recombination events and its impact on the natural parasite population structure. This paper reviews the results and techniques used to demonstrate the existence of sex in trypanosomatids, the inheritance of kinetoplast DNA (maxi- and minicircles), the impact of genetic exchange in these parasites, and how it can contribute to the phenotypic diversity of natural populations. Full article

(This article belongs to the Special Issue Host-Parasite Interactions: Trends in Molecular Ecology)

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47 pages, 9432 KiB

Open AccessReview

Review of Venoms of Non-Polydnavirus Carrying Ichneumonoid Wasps

by Donald L. J. Quicke and Buntika A. Butcher

Biology 2021, 10(1), 50; https://doi.org/10.3390/biology10010050 - 12 Jan 2021

Cited by 12 | Viewed by 3696

Abstract

Parasitoids are predominantly insects that develop as larvae on or inside their host, also usually another insect, ultimately killing it after various periods of parasitism when both parasitoid larva and host are alive. The very large wasp superfamily Ichneumonoidea is composed of parasitoids [...] Read more.

Parasitoids are predominantly insects that develop as larvae on or inside their host, also usually another insect, ultimately killing it after various periods of parasitism when both parasitoid larva and host are alive. The very large wasp superfamily Ichneumonoidea is composed of parasitoids of other insects and comprises a minimum of 100,000 species. The superfamily is dominated by two similarly sized families, Braconidae and Ichneumonidae, which are collectively divided into approximately 80 subfamilies. Of these, six have been shown to release DNA-containing virus-like particles, encoded within the wasp genome, classified in the virus family Polydnaviridae. Polydnaviruses infect and have profound effects on host physiology in conjunction with various venom and ovarial secretions, and have attracted an immense amount of research interest. Physiological interactions between the remaining ichneumonoids and their hosts result from adult venom gland secretions and in some cases, ovarian or larval secretions. Here we review the literature on the relatively few studies on the effects and chemistry of these ichneumonoid venoms and make suggestions for interesting future research areas. In particular, we highlight relatively or potentially easily culturable systems with features largely lacking in currently studied systems and whose study may lead to new insights into the roles of venom chemistry in host-parasitoid relationships as well as their evolution. Full article

(This article belongs to the Special Issue Host-Parasite Interactions: Trends in Molecular Ecology)

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