Parasite Interactions Research Articles

Investigating Cryptosporidium spp. Using Genomic, Proteomic and Transcriptomic Techniques: Current Progress and Future Directions.

Cryptosporidiosis is a widespread disease caused by the parasitic protozoan Cryptosporidium spp., which infects various vertebrate species, including humans. Once unknown as a gastroenteritis-causing agent, Cryptosporidium spp. is now recognized as a pathogen causing life-threatening disease, especially in immunocompromised individuals such as AIDS patients. Advances in diagnostic methods and increased awareness have led to a significant shift in the perception of Cryptosporidium spp. as a pathogen. Currently, genomic and proteomic studies play a main role in understanding the molecular biology of this complex-life-cycle parasite. Genomics has enabled the identification of numerous genes involved in the parasite's development and interaction with hosts. Proteomics has allowed for the identification of protein interactions, their function, structure, and cellular activity. The combination of these two approaches has significantly contributed to the development of new diagnostic tools, vaccines, and drugs for cryptosporidiosis. This review presents an overview of the significant achievements in Cryptosporidium research by utilizing genomics, proteomics, and transcriptomics approaches.

Nestedness and beta diversity of gastrointestinal helminth communities in common warthogs, Phacochoerus africanus (Suidae), at 2 localities in South Africa.

Few studies have investigated the ecological interactions between wild species of Suidae and their parasites, leaving our knowledge concerning this host–parasite system fragmented. In the present study, we applied network studies to analyse community nestedness in helminth assemblages of common warthogs, Phacochoerus africanus (Gmelin) (Suidae). Helminth data were compiled from 95 warthogs, including young and adult males and females, from 2 different conservation areas in Mpumalanga and Limpopo Provinces, South Africa, collected monthly over a period of 1 year each. The aim was to study the effect of host sex, age and season of sampling on the structure of helminth infracommunities harboured by the warthogs and to search for non-random structural patterns in the warthog–helminth interaction networks. Furthermore, we investigated the influence of a warthog's age, sex and season of sampling on beta diversity and dark diversity of their helminth infracommunities. Lastly, we asked whether the effects of host sex, age and sampling season on helminth communities differed between the 2 localities. We found that helminth communities of warthogs were nested and host–parasite interactions were influenced by all 3 factors as well as combinations thereof. However, the resulting patterns differed at the 2 localities, indicating that local environmental processes are important drivers of community structure.

Pre-eclampsia and eclampsia pathogenesis utilizes iron released by a hemolytic protozoan parasite

Pre-eclampsia and eclampsia cause unfortunate pregnancies, and currently affect 8% to 10% of pregnancies world-wide, causing ∼ 16% of maternal mortalities. The causations of pre-eclampsia and eclampsia (pre-eclampsia with cerebral seizures and convulsions) are unknown. Several causes have been proposed, including infections of the oral, urinary or genital tracts by certain bacterial or viral pathogens. Pre-eclampsia studies have compiled lists of cytokine signatures to diagnose pre-eclampsia, but these cytokine signatures can also be analyzed to deduce the causations of pre-eclampsia and eclampsia. These cytokines indicate that pre-eclampsia and eclampsia can be caused by certain Gram-negative bacteria or viral pathogen infections boosted by an almost asymptomatic strain of a hemolytic protozoan parasite, such as Trichomonas vaginalis. Such protozoan parasite interactions can provide iron to chronic and/or latent infections by certain Gram-negative bacteria or viral pathogens to reactivate them and increase their virulence to cause pre-eclampsia and/or eclampsia. In summary, the hypothesis of this paper is that one event reactivating pathogens to cause pre-eclampsia is the reappearance of nutrients including iron, provided by a second pathogen. The second pathogen is believed to be the hemolytic protozoan parasite T. vaginalis, a commonly transmitted pathogen which disrupts blood cells to obtain iron for itself and which can enable the reactivation of the first pathogen which was suppressed by iron deprivation. The released iron boosts pathogen infections, impairs important immune cells, and even a small amount of free iron can be repeatedly recycled by reduction–oxidation reactions to cause oxidative stress damage to major organs, including the kidneys.

Detection of Secreted Effector Proteins from Phelipanche aegyptiaca During Invasion of Melon Roots.

Parasites can interact with their host plants through the induction and delivery of secreted effector proteins that facilitate plant colonization by decomposing plant cell walls and inhibiting plant immune response to weaken the defense ability of the host. Yet effectors mediating parasitic plant-host interactions are poorly understood. Phelipanche aegyptiaca is an obligate root parasite plant causing severe yield and economic losses in agricultural fields worldwide. Host resistance against P. aegyptiaca occurred during the attachment period of parasitism. Comparative transcriptomics was used to assess resistant and susceptible interactions simultaneously between P. aegyptiaca and two contrasting melon cultivars. In total, 2,740 secreted proteins from P. aegyptiaca were identified here. Combined with transcriptome profiling, 209 candidate secreted effector proteins (CSEPs) were predicted, with functional annotations such as cell wall degrading enzymes, protease inhibitors, transferases, kinases, and elicitor proteins. A heterogeneous expression system in Nicotiana benthamiana was used to investigate the functions of 20 putatively effector genes among the CSEPs. Cluster 15140.0 can suppress BAX-triggered programmed cell death in N. benthamiana. These findings showed that the prediction of P. aegyptiaca effector proteins based on transcriptomic analysis and multiple bioinformatics software is effective and more accurate, providing insights into understanding the essential molecular nature of effectors and laying the foundation of revealing the parasite mechanism of P. aegyptiaca, which is helpful in understanding parasite-host plant interaction.

Haemoproteus parasites and passerines: the effect of local generalists on inferences of host-parasite co-phylogeny in the British Isles.

Host–parasite associations provide a benchmark for investigating evolutionary arms races and antagonistic coevolution. However, potential ecological mechanisms underlying such associations are difficult to unravel. In particular, local adaptations of hosts and/or parasites may hamper reliable inferences of host–parasite relationships and the specialist–generalist definitions of parasite lineages, making it problematic to understand such relationships on a global scale. Phylogenetic methods were used to investigate co-phylogenetic patterns between vector-borne parasites of the genus Haemoproteus and their passeriform hosts, to infer the ecological interactions of parasites and hosts that may have driven the evolution of both groups in a local geographic domain. As several Haemoproteus lineages were only detected once, and given the occurrence of a single extreme generalist, the effect of removing individual lineages on the co-phylogeny pattern was tested. When all lineages were included, and when all singly detected lineages were removed, there was no convincing evidence for host–parasite co-phylogeny. However, when only the generalist lineage was removed, strong support for co-phylogeny was indicated, and ecological interactions could be successfully inferred. This study exemplifies the importance of identifying locally abundant lineages when sampling host–parasite systems, to provide reliable insights into the precise mechanisms underlying host–parasite interactions.

Survey and Molecular Characterization of Sarcocystidae protozoa in Wild Cricetid Rodents from Central and Southern Chile.

In Chile, studies of parasites from the family Sarcocystidae (Apicomplexa) have mostly been related to domestic animals. We aimed to assess the presence of Sarcocystidae taxa in cricetid rodents from Central and Southern Chile. We studied 207 rodents, encompassing six species, from 13 localities. We isolated DNA from tissue samples, amplified the Sarcocystidae 18S rRNA gene with polymerase chain reaction, and performed phylogenetic analyses using maximum likelihood and Bayesian inferences. In addition, we examined blood smears and performed histological studies in organs from Sarcocystidae DNA-positive animals. Three specimens were DNA-positive and three genotypes were retrieved and named: Sarcocystis sp. P61, related to Sarcocystis strixi, was detected in two Abrothrix olivacea. Toxoplasmatinae gen. sp. P99 was retrieved from those same two specimens, and was related to Toxoplasma and other genera, although it branched independently. Besnoitia sp. R34 was detected in one Abrothrix hirta, and was clustered with congeneric species associated with rodents. No protozoa were found during microscopic studies; thus, it was not possible to confirm parasitic interactions rather than accidental encounters. However, the close relatedness of the retrieved genotypes to parasites of rodents supports the hypothesis of host-parasite associations. All three genotypes are suggested as potential new taxa, including a putative new genus.

Carbohydrate derivatives fight against malaria parasite as anti-plasmodial agents

Malaria, a prevalent fatal disease around the world is caused by Plasmodium sp. and is transmitted by the bite of female Anopheles mosquito. It is leading cause of death in this century among most infectious diseases. Drug resistance was reported for almost every front-line drug against the deadliest species of the malarial parasite, i.e., Plasmodium falciparum. In the evolutionary arms race between parasite and existing arsenals of drugs new molecules having novel mechanism of action is urgently needed to overcome the drug resistance. In this review, we have discussed the importance of carbohydrate derivatives of different class of compounds as possible antimalarials with emphasis on mode of action, rational design, and SAR with improved efficacy. Carbohydrate-protein interactions are increasingly important for medicinal chemists and chemical biologists to understand the pathogenicity of the parasite. Less is known about the carbohydrate-protein interactions and pathogenicity in the Plasmodium parasite. With the increased knowledge on protein-sugar interaction and glycomics of Plasmodium parasites, carbohydrate derivatives can surpass the existing biochemical pathways responsible for drug resistance. The new candidates with novel mode of action will prove to be a potent antimalarial drug candidate without any parasitic resistance.

Effects of temperature on azamethiphos sensitivity profile of Caligus rogercresseyi

It is well known that the biology of Caligus rogercresseyi is strongly affected by environmental conditions such as temperature. However, little is known if these variables can affect antiparasitic sensitivity. In this context, the aim of the study was to determine how temperature and light can induce changes in the parasite sensitivity profile to azamethiphos. Temperatures of 9, 12, 15, and 17 °C and two light conditions were evaluated through sensitivity evaluation in vitro bioassays. Parasites were exposed to an azamethiphos concentration gradient of 0, 3, 10, 30, 100, and 300 ppb. A range of temperature between 12 °C and 15 °C did not significantly change the sensitivity profile of the parasite. Moreover, light conditions did not induce significant changes in the sensitivity profile either. However, the temperature of 9 °C induced higher effective concentrations (EC50) than the rest of the temperatures, but also lower affectation and mortality of the parasite. This evidence suggested that sensitivity to azamethiphos decreases with temperature, regardless of the light conditions. These results are considered relevant since strong variations of environmental conditions (like temperature) among seasons and geographical areas could impact salmon–parasite interactions, but also the effectiveness of the treatments applied in the salmon industry. Even more, in a climate change context, for which temperature is considered one of the main variables, it is expected that important changes occur in the biology, metabolism, and population dynamics of parasites, fish, and marine animals, being these changes a matter of concern in the future sustainability of aquaculture.

Disentangling the Belowground Web of Biotic Interactions in Temperate Coastal Grasslands: From Fundamental Knowledge to Novel Applications

Grasslands represent an essential part of terrestrial ecosystems. In particular, coastal grasslands are dominated by the influence of environmental factors resulting from sea–land interaction. Therefore, coastal grasslands are extremely heterogeneous both spatially and temporally. In this review, recent knowledge in the field of biotic interactions in coastal grassland soil is summarized. A detailed analysis of arbuscular mycorrhiza symbiosis, rhizobial symbiosis, plant–parasitic plant interactions, and plant–plant interactions is performed. The role of particular biotic interactions in the functioning of a coastal grassland ecosystem is characterized. Special emphasis is placed on future directions and development of practical applications for sustainable agriculture and environmental restoration. It is concluded that plant biotic interactions in soil are omnipresent and important constituents in different ecosystem services provided by coastal grasslands.

The interaction of Schistosoma mansoni infection with diabetes mellitus and obesity in mice

Human schistosomiasis is one of the most prevalent parasitic diseases worldwide. Various host factors can affect the host–parasite interactions. Therefore, the aim of the present work was to determine the parasitological, histopathological, biochemical, and immunological status of Schistosoma mansoni-infected hosts with metabolic disorders to identify the underlying possible mechanisms of these comorbidities. The study animals were divided into four groups. Group I represented the control groups, namely, the normal control group, the S. mansoni-infected control group, and the noninfected type 1 diabetes (T1DM), type 2 diabetes (T2DM), and obesity groups. The mice of the other three groups underwent induction of T1DM (Group II), T2DM (Group III) and obesity (Group IV) before being infected with S. mansoni. All mice were subjected to body weight measurement, blood glucose and insulin assessment, parasitological evaluation of adult worm count, tissue egg count and intestinal oogram. Histopathological and immunohistochemical study using anti-glial fibrillary acidic protein (GFAP) in hepatic stellate cells (HSCs) and image analysis of Masson’s trichrome-stained liver sections using ImageJ (Fiji) software were carried out. Additionally, immunological analysis of tumour necrosis factor (TNF) beta, interleukin-5 (IL-5), IL-10, Forkhead box P3 (FOXP3) and pentraxin 3 (PTX3) levels besides biochemical study of total lipid profile were evaluated. The present study revealed a significant increase in the adult worm count and tissue egg output in the obesity group compared to the infected control group. The oogram of counted eggs showed prevalence of immature eggs in T1DM group, while T2DM and obese groups showed prevalence of mature eggs. The fibrosis area percentage showed significant increase in T2DM and obese groups while it was decreased in T1DM group in comparison to infected control group. Our data also showed significant increase in the levels of TNF-β, IL-5, PTX3 in T1DM, T2DM and obesity groups in comparison to infected control group, whilst the levels of FOXP3 and IL-10 were increased in the infected groups in comparison to their noninfected controls. Moreover, infected T1DM, T2DM and obesity groups showed higher blood glucose and lipid profile in comparison to the infected control group. However, these parameters were improved in comparison to their noninfected controls. In sum, induction of T2DM and obesity increased tissue egg counts, mature egg percentage, and fibrosis density, while schistosome infection induced changes in the lipid profile and blood glucose levels in infected diabetic and obese groups and impacted favorably insulin levels in obese mice. By better understanding the complexities of host–parasite interactions, efforts to reduce the burden of these debilitating diseases can be improved.

Occurrence of five distinct clades of mermithid nematodes (Nematoda: Mermithidae) infecting black fly larvae (Diptera: Simuliidae) in tropical streams in Malaysia.

Mermithids are the most common parasites of black flies and are associated with host feminization and sterilization in infected hosts. However, information on the species / lineage of black fly mermithids in Southeast Asia, including Malaysia requires further elucidation. In this study, mermithids were obtained from black fly larvae collected from 138 freshwater stream sites across East and West Malaysia. A molecular approach based on nuclear-encoded 18S ribosomal RNA (18S rRNA) gene was used to identify the species identity / lineage of 77 nematodes successfully extracted and sequenced from the specimens collected. Maximum likelihood and neighbor-joining phylogenetic analyses demonstrated five distinct mermithid lineages. Four species delimitation analyses: automated simultaneous analysis phylogenetics (ASAP), maximum likelihood Poisson tree processes with Bayesian inferences (bPTP_ML), generalized mixed yule coalescent (GMYC) and single rate Poisson tree processes (PTP) were applied to delimit the species boundaries of mermithid lineages in this data set along with genetic distance analysis. Data analysis supports five distinct lineages or operational taxonomic units for mermithids in the present study, with two requiring further investigation as they may represent intraspecific variation or closely related taxa. One mermithid lineage was similar to that previously observed in Simulium nigrogilvum from Thailand. Co-infection with two mermithids of different lineages was observed in one larva of Simulium trangense. This study represents an important first step towards exploring other aspects of host - parasite interactions in black fly mermithids.

A meta‐analysis of how parasites affect host consumption rates

Parasites are known to mediate trophic interactions and can, for example, modify how consumers acquire resources. These modifications of host feeding behaviour can be imposed through three interconnected mechanisms affecting: 1) host food acquisition, 2) host food digestion or 3) host energy budgets. As a result, infected hosts may consume more, less or the same amount of food compared to their uninfected conspecifics. It is commonly assumed that infected hosts have lower consumption rates than uninfected hosts, but a comprehensive quantitative synthesis investigating the effects of parasites on host consumption rate has been lacking thus far. To fill this knowledge gap, we systematically searched for experimental studies that evaluated changes in consumption rate of infected vs uninfected hosts. In total, we extracted 158 effect sizes from 68 studies. We then performed meta‐analyses of mean differences in host consumption rates and their variation. The analyses were carried out for all taxonomic groups as well as separately for vertebrate and invertebrate hosts. The main‐effects meta‐analyses confirmed a generally negative effect of parasites on host consumption rates; infected hosts consumed on average 25% less food than their uninfected conspecifics. In addition, there was a significant increase in the variability in host consumption rate, on average by 25%, indicating that parasites can have variable effects on the foraging behaviour of their hosts. The meta‐regression models revealed that several moderator variables related to host and parasite characteristics influence host consumption rate. Experimental infection had a stronger influence on variance effects than natural infection. Parasitic infections reduced consumption rate of vertebrate hosts by 28% and thus more strongly than those of invertebrates, which were reduced by 22%. We conclude with recommendations to facilitate future ecological research syntheses on host–parasite interactions and beyond.

Proteomic characterization of Opisthorchis felineus exosome-like vesicles and their uptake by human cholangiocytes

The epidemiologically important food-borne trematode Opisthorchis felineus infests the liver biliary tract of fish-eating mammals and causes disorders, including bile duct neoplasia. Many parasitic species release extracellular vesicles (EVs) that mediate host–parasite interaction. Currently, there is no information on O. felineus EVs.Using gel electrophoresis followed by liquid chromatography coupled with tandem mass spectrometry, we aimed to characterize the proteome of EVs released by the adult O. felineus liver fluke. Differential abundance of proteins between whole adult worms and EVs was assessed by semiquantitative iBAQ (intensity-based absolute quantification). Imaging, flow cytometry, inhibitor assays, and colocalization assays were performed to monitor the uptake of the EVs by H69 human cholangiocytes.The proteomic analysis reliably identified 168 proteins (at least two peptides matched a protein). Among major proteins of EVs were ferritin, tetraspanin CD63, helminth defense molecule 1, globin 3, saposin B type domain-containing protein, 60S ribosomal protein, glutathione S-transferase GST28, tubulin, and thioredoxin peroxidase. Moreover, as compared to the whole adult worm, EVs proved to be enriched with tetraspanin CD63, saposin B, helminth defense molecule 1, and Golgi-associated plant pathogenesis-related protein 1 (GAPR1). We showed that EVs are internalized by human H69 cholangiocytes via clathrin-dependent endocytosis, whereas phagocytosis and caveolin-dependent endocytosis do not play a substantial role in this process.Our study describes for the first time proteomes and differential abundance of proteins in whole adult O. felineus worms and EVs released by this food-borne trematode. Studies elucidating the regulatory role of individual components of EVs of liver flukes should be continued to determine which components of EV cargo play the most important part in the pathogenesis of fluke infection and in a closely linked pathology: bile duct neoplasia. SignificanceThe food-borne trematode Opisthorchis felineus is a pathogen that causes hepatobiliary disorders in humans and animals. Our study describes for the first time the release of EVs by the liver fluke O. felineus, their microscopic and proteomic characterization, and internalization pathways by human cholangiocytes. Differential abundance of proteins between whole adult worms and EVs was assessed. EVs are enriched with canonical EV markers as well as parasite specific proteins, i.e. tetraspanin CD63, saposin B, helminth defense molecule 1, and others. Our findings will form the basis of the search for potential immunomodulatory candidates with therapeutic potential in the context of inflammatory diseases, as well as novel vaccine candidates.

Haemosporidian blood parasites of passerine birds in north-western Siberia

Host–parasite interactions include effects on both proximate and ultimate levels: parasite infections affect individual’s fitness and play a significant role in shaping the life history of host species. Global environmental changes as well as significant shifts in abiotic factors might impact the dynamics of parasite–host interactions, especially in Arctic regions, where the climate is changing at an alarming rate. With global warming, parasites and their vectors are predicted to spread to polar latitudes, and it is crucial to follow the changes occurring in the ecosystems in the era of global changes. We studied blood parasites (Haemosporidae) of passerine birds (Passeriformes: Aves) in southwest Yamal (north-western Siberia) using genetic and morphological methods. We found an overall parasite prevalence of 76.3%, with highest values for Leucocytozoon (72.0%) and lower values for Parahaemoproteus and Plasmodium (8.9 and 8.2%, respectively). We determined 26 genetic lineages in total, five of them were novel. The most common parasite lineages were TRPIP2 (18%), BT1 (14%), novel ACAFLA06 (13%), BT2 (7%), novel ACAFLA07 (6%), BT4 (5%) for Leucocytozoon; SISKIN1 (4%) for Parahaemoproteus; TURDUS1 (4%) for Plasmodium. For redpoll (Acanthis flammea), brambling (Fringilla montifringilla), bluethroat (Luscinia svecica) and little bunting (Emberiza pusilla) overall prevalence exceeded 90%. We also found significant differences in prevalence and lineage composition between sample sites, species and sexes, and a positive correlation between number of infections and host body mass. Our study provides knowledge about haemosporidian infections in the region, which had been barely studied for blood parasites. Gathered information is essential for the future monitoring and assessing potential shifts due to global change.

Defining the filarial N-glycoproteome by glycosite mapping in the human parasitic nematode Brugia malayi

N-linked glycosylation is a critical post translational modification of eukaryotic proteins. N-linked glycans are present on surface and secreted filarial proteins that play a role in host parasite interactions. Examples of glycosylated Brugia malayi proteins have been previously identified but there has not been a systematic study of the N-linked glycoproteome of this or any other filarial parasite. In this study, we applied an enhanced N-glyco FASP protocol using an engineered carbohydrate-binding protein, Fbs1, to enrich N-glycosylated peptides for analysis by LC-MS/MS. We then mapped the N-glycosites on proteins from three host stages of the parasite: adult female, adult male and microfilariae. Fbs1 enrichment of N-glycosylated peptides enhanced the identification of N-glycosites. Our data identified 582 N-linked glycoproteins with 1273 N-glycosites. Gene ontology and cell localization prediction of the identified N-glycoproteins indicated that they were mostly membrane and extracellular proteins. Comparing results from adult female worms, adult male worms, and microfilariae, we find variability in N-glycosylation at the protein level as well as at the individual N-glycosite level. These variations are highlighted in cuticle N-glycoproteins and adult worm restricted N-glycoproteins as examples of proteins at the host parasite interface that are well positioned as potential therapeutic targets or biomarkers.

Half of a forest bird community infected with haemosporidian parasites

IntroductionParasites play important roles in ecosystems. Through their interactions with host and vector species, they are capable of changing the behavior and population dynamics of their host species, and the shape of entire communities. Over the past years, many studies have acknowledged the role of parasitism for host populations and communities and discovered their important regulatory functions for many vertebrate populations. Although birds are a well-studied group of vertebrates, the infection patterns of endoparasites at the community level are not fully understood. Some bird species and families are known to have a higher susceptibility to certain endoparasites than others, which may be driven by their abundance in the community.MethodsOver the course of four consecutive breeding seasons (2019–2022), we monitored the patterns of endoparasite infections in a bird community of a temperate forest ecosystem. We sampled 483 birds belonging to 29 Palearctic species and investigated the prevalence of blood parasites (haemosporidian parasites) andTrichomonasspp. using molecular methods.ResultsWe found an overall prevalence of 48.1% of haemosporidians belonging to 53 genetic lineages of the three generaHaemoproteus,Leucocytozoon, andPlasmodiumspp. While the bird families Turdidae (94%) and Paridae (76%) showed a high prevalence of haemosporidians, Certhiidae, and Picidae were not infected (0%). Host–parasite network analysis detected high variability in interactions. Infections withTrichomonasspp. were not observed in the forest bird community.DiscussionWe found that the prevalence and lineage diversity of haemosporidian parasites differed between avian families and that the parasite prevalence of a family could not serve as a predictor of lineage diversity. To further assess the consequences of these host–parasite interactions for bird communities, future research should aim to disentangle the infection pathways in different ecosystems while also considering the vector community and environmental factors.

Anatomical, phenological and genetic aspects of the host-parasite relationship between Andrena vaga (Hymenoptera) and Stylops ater (Strepsiptera).

Stylops ater is an endoparasite of the mining bee Andrena vaga with extreme sexual dimorphism and hypermetamorphosis. Its population structure, parasitization mode, genetic diversity and impact on host morphology were examined in nesting sites in Germany to better understand this highly specialized host–parasite interaction. The shift in host emergence due to stylopization was proven to be especially strong in A. vaga. Around 10% of bees hosted more than 1 Stylops, with at maximum 4. A trend in Stylops' preference for hosts of their own sex and a sex-specific position of extrusion from the host abdomen was found. Invasion of Andrena eggs by Stylops primary larvae was depicted for the first time. Cephalothoraces of female Stylops were smaller in male and pluristylopized hosts, likely due to lower nutrient supply. The genes H3, 18S and cytochrome c oxidase subunit 1 were highly conserved, revealing near-absence of local variation within Stylops. Ovaries of hosts with male Stylops contained poorly developed eggs while those of hosts with female Stylops were devoid of visible eggs, which might be due to a higher protein demand of female Stylops. Male Stylops, which might have a more energy-consuming development, led to a reduction in head width of their hosts. Host masculinization was present in the leaner shape of the metabasitarsus of stylopized females and is interpreted as a by-product of manipulation of the host's endocrine system to shift its emergence. Stylopization intensified tergal hairiness, most strongly in hosts with female Stylops, near the point of parasite extrusion, hinting towards substance-induced host manipulation.

Drivers behind co-occurrence patterns between pathogenic bacteria, protozoa, and helminths in populations of the multimammate mouse, Mastomys natalensis

Advances in experimental and theoretical work increasingly suggest that parasite interactions within a single host can affect the spread and severity of wildlife diseases. Yet empirical data to support predicted co-infection patterns are limited due to the practical challenges of gathering convincing data from animal populations and the stochastic nature of parasite transmission. Here, we investigated co-infection patterns between micro- (bacteria and protozoa) and macroparasites (gastro-intestinal helminths) in natural populations of the multimammate mouse (Mastomys natalensis). Fieldwork was performed in Morogoro (Tanzania), where we trapped 211 M. natalensis and tested their behaviour using a modified open-field arena. All animals were checked for the presence of helminths in their gastro-intestinal tract, three bacteria (Anaplasma, Bartonella, and Borrelia) and two protozoan genera (Babesia and Hepatozoon). Besides the presence of eight different helminth genera (reported earlier), we found that 19% of M. natalensis were positive for Anaplasma, 10% for Bartonella, and 2% for Hepatozoon species. Hierarchical modelling of species communities was used to investigate the effect of the different host-related factors on these parasites’ infection probability and community structure. Our results show that the infection probability of Bartonella increased with the host's age, while the infection probability of Anaplasma peaked when individuals reached adulthood. We also observed that less explorative and stress-sensitive individuals had a higher infection probability with Bartonella. Finally, we found limited support for within-host interactions between micro-and macroparasites, as most co-infection patterns could be attributed to host exposure time.

Cryptosporidium secretome sheds new light on host–parasite interactions

Invasive Cryptosporidium sporozoites contain organelles that secrete unique proteins to facilitate invasion and remodeling of the infected cell. By identifying a novel secretory organelle, ‘small granules’, and defining the global content of all the secretory organelles, Guérin et al. set the stage to uncover molecular determinants of virulence at the host cell interface.

10 Preliminary Effect of Cottonseed as a Source of Gossypol on Hepatic Portal Blood Flow as an Indicator of Metabolism in Meat does Artificially Infected withHaemonchus Contortus

Abstract Cottonseed diets provide animals with increased levels of protein and energy to support growth. Recently, it was suggested that although the gossypol content of cottonseed could result in adverse animal reproduction, it could have a potential anthelmintic property beneficial to small ruminant operations. In addition, gossypol is primarily cleared and excreted from the animal via liver glucuronidation, which is a primary pathway for steroid clearance in ruminants. The objective of this experiment was to determine the effect of a cottonseed diet and parasite load on the hepatic portal blood flow an indicator of hepatic clearance rates and metabolism. Forty Boer x Spanish cross does were assigned to of 4 treatments (n = 10 per treatment group) in a 2x2 factorial design consisting of cottonseed supplementation and no parasite infection (CNP), cottonseed supplementation plus artificial infection with Haemonchus contortus (CP), commercial pellets with no parasite infection (NCNP), or commercial pellets plus artificial infection with Haemonchus contortus (NCP). On week 8 post-treatment, hepatic portal blood flow measurements were collected via Doppler ultrasonography on the right side of the animal at the 10th intercostal space. Blood flow was then calculated using the following equation: blood flow (mL/min) = mean velocity (cm/s) x vessel area x 60 seconds. The mean velocity was calculated by the following formula: (systolic – diastolic)/pulsatility index. Hepatic portal blood flow and body weight of does were analyzed with a One-way ANOVA using the MIXED procedure of SAS with diet and parasite load as the main effects and their interactions. A diet by parasite interaction (P = 0.026) was observed for the mean velocity of the hepatic portal vein, which was decreased in CP versus CNP treatments. A diet by parasite interaction (P = 0.012) was observed for the diameter of the hepatic portal vein, which was increased in the CP treatment versus all other groups. However, absolute hepatic portal blood flow was not different (P > 0.12) amongst treatments. A tendency for the main effect (P = 0.087) of diet was observed for hepatic portal blood flow relative to body weight, which was an increase in cottonseed (27.8 ±.8 mL/min*kg) versus NCS (23.2 ±.8 mL/min*kg). Body weight was not different (P > 0.35) amongst treatments at the time of Doppler ultrasound examination. In conclusion, cottonseed interacted with parasites to decrease mean velocity and increase the diameter of the portal vein. In addition, cottonseed appears to increase liver blood flow relative to body weight. This change in relative liver blood flow could have implications for mediating hepatic metabolism and clearance.