Levels Of Parasitism Research Articles

Individual heterogeneity in ixodid tick infestation and prevalence of Borrelia burgdorferi sensu lato in a northern community of small mammalian hosts.

Heterogeneous aggregation of parasites between individual hosts is common and regarded as an important factor in understanding transmission dynamics of vector-borne diseases. Lyme disease is vectored by generalist tick species, yet we have a limited understanding of how individual heterogeneities within small mammal host populations affectthe aggregation of ticks and likelihood of infection. Male hosts often have higher parasite and infection levels than females, but whether this is linked to sexual body size dimorphism remains uncertain. Here, we analysed how host species, sex, and body mass influenced Ixodes ricinus tick infestations and the infection prevalence of Borrelia burgdorferi sensu lato (s.l.) in three species of small mammals involved in the enzootic transmission cycle of Lyme disease in Norway from 2018 to 2022. Larval and nymphal ticks were found on 98% and 34% of all individual hosts, respectively. In bank voles and wood mice, both larval and nymphal tick infestation and infection probability increased with body mass, and it increased more with mass for males than for females. Tick infestation in the common shrew increased with body mass and was higher in males, while pathogen infection was higher in females. Sex-biases in infestation did not correspond with level of sexual body mass dimorphism across species. This study contributes to our understanding of how individual heterogeneity among small mammalian hosts influences I. ricinus tick aggregation and prevalence of B. burgdorferi s.l. at northern latitudes.

Pathways linking nutrient enrichment, habitat structure, and parasitism to host-resource interactions.

Human activities simultaneously alter nutrient levels, habitat structure, and levels of parasitism. These activities likely have individual and joint impacts on food webs. Furthermore, there is particular concern that nutrient additions and changes to habitat structure might exacerbate the size of epidemics and impacts on host density. We used a well-studied zooplankton-fungus host-parasite system and experimental whole water column enclosures to factorially manipulate nutrient levels, habitat structure (specifically: mixing), and presence of parasites. Nutrient addition increased infection prevalence, density of infected hosts, and total host density. We hypothesized that nutrients, mixing, and parasitism were linked in multiple ways, including via their combined effects on phytoplankton (resource) abundance, and we used structural equation modeling to disentangle these pathways. In the absence of the parasite, both nutrients and mixing increased abundance of phytoplankton, whereas host density was negatively related to phytoplankton abundance, suggesting a mixture of bottom-up and top-down control of phytoplankton. In the presence of the parasite, nutrients still increased phytoplankton abundance but mixing no longer did, and there was no longer a significant relationship between host density and phytoplankton. This decoupling of host-resource dynamics may have resulted from reduced grazing due to illness-mediated changes in feeding behavior. Overall, our results show that the impact of one human activity (e.g., altered habitat structure) might depend on other human impacts (e.g., parasite introduction). Fortunately, carefully designed experiments and analyses can help tease apart these multifaceted relationships, allowing us to understand how human activities alter food webs, including interactions between hosts and their parasites and resources.

Integrating databases for spatial analysis of parasite-host associations and the novel Brazilian dataset

Incomplete information on parasites, their associated hosts, and their precise geographical location hampers the ability to predict disease emergence in Brazil, a continental-sized country characterised by significant regional disparities. Here, we demonstrate how the NCBI Nucleotide and GBIF databases can be used as complementary databases to study spatially georeferenced parasite-host associations. We also provide a comprehensive dataset of parasites associated with mammal species that occur in Brazil, the Brazilian Mammal Parasite Occurrence Data (BMPO). This dataset integrates wild mammal species’ morphological and life-history traits, zoonotic parasite status, and zoonotic microparasite transmission modes. Through meta-networks, comprising interconnected host species linked by shared zoonotic microparasites, we elucidate patterns of zoonotic microparasite dissemination. This approach contributes to wild animal and zoonoses surveillance, identifying and targeting host species accountable for disproportionate levels of parasite sharing within distinct biomes. Moreover, our novel dataset contributes to the refinement of models concerning disease emergence and parasite distribution among host species.

Prospects of classical biological control of papaya mealybug in Kenya: Performance of its exotic parasitoid, Acerophagus papayae, under laboratory and field conditions

Papaya mealybug (PMB), Paracoccus marginatus, native to Mexico and Central America, invaded Kenya in 2016 causing severe yield losses of between 57% and 91% and £2224/ha household economic losses annually. A classical biological program for PMB involved the importation of Acerophagus papayae, a koinobiont endoparasitoid, from Ghana into the quarantine facility at Kenya Agricultural and Livestock Research Organization, Muguga. Laboratory bioassays were conducted to evaluate the suitability of A. papayae to parasitize PMB. Parasitism rates, sex ratio and development time of the parasitoid were evaluated under choice and no-choice experimental conditions. High parasitism rates of 72.5 ± 5.9 and 75.0 ± 3.8% were recorded in third instar and adult female PMB, respectively, and lower parasitism rates of 43.8 ± 4.6 % were recorded in second instars, under no-choice test conditions. Significant differences in host choice were noted when A. papayae was offered several host stages, with third instars being preferred over second instars. Adult females were preferred over third instars. Adult parasitoids were released and monitored for their establishment at six papaya farms in the Coastal region of Kenya from December 2021 to November 2022. Parasitoid establishment was recovered within the first month of release. Parasitism levels varied across the sites with the highest parasitism of 72.89 % recorded in Kwale. Findings from this study highlight the potential of A. papayae as a good candidate for biological control of PMB in Kenya and Africa beyond.

Mitochondrion of the Trypanosoma brucei long slender bloodstream form is capable of ATP production by substrate-level phosphorylation.

The long slender bloodstream form Trypanosoma brucei maintains its essential mitochondrial membrane potential (ΔΨm) through the proton-pumping activity of the FoF1-ATP synthase operating in the reverse mode. The ATP that drives this hydrolytic reaction has long been thought to be generated by glycolysis and imported from the cytosol via an ATP/ADP carrier (AAC). Indeed, we demonstrate that AAC is the only carrier that can import ATP into the mitochondrial matrix to power the hydrolytic activity of the FoF1-ATP synthase. However, contrary to expectations, the deletion of AAC has no effect on parasite growth, virulence or levels of ΔΨm. This suggests that ATP is produced by substrate-level phosphorylation pathways in the mitochondrion. Therefore, we knocked out the succinyl-CoA synthetase (SCS) gene, a key mitochondrial enzyme that produces ATP through substrate-level phosphorylation in this parasite. Its absence resulted in changes to the metabolic landscape of the parasite, lowered virulence, and reduced mitochondrial ATP content. Strikingly, these SCS mutant parasites become more dependent on AAC as demonstrated by a 25-fold increase in their sensitivity to the AAC inhibitor, carboxyatractyloside. Since the parasites were able to adapt to the loss of SCS in culture, we also analyzed the more immediate phenotypes that manifest when SCS expression is rapidly suppressed by RNAi. Importantly, when performed under nutrient-limited conditions mimicking various host environments, SCS depletion strongly affected parasite growth and levels of ΔΨm. In totality, the data establish that the long slender bloodstream form mitochondrion is capable of generating ATP via substrate-level phosphorylation pathways.

Single Nucleotide Polymorphisms in Plasmodium falciparum Genes: Their Roles in Antimalarial Drugs Resistance and Recent Detection Strategies

Introduction: Malaria is a serious tropical disease with Plasmodium falciparum as its most well-known causative parasite for producing higher levels of late stage parasites that leads to sequestration in vital organs which could lead to death. There is a growing trend of antimalarial drugs resistance against Plasmodium falciparum. Molecular assessment using polymerase chain reaction could trace the presence of mutation and also determine single-nucleotide polymorphism (SNP) in Plasmodium falciparum genes. This SNP can determine the particular population’s response to antimalarial drugs. Objectives: This study aims to examine the relationship between SNP in Plasmodium falciparum genes and antimalarial drugs resistance. Methods: Literature searches were carried out through various databases which were then collected and analyzed. Result: We identified various SNPs from eleven known genes in Plasmodium falciparum, each SNPs causes a different mechanism which contributes to antimalarial drug resistance. Mechanisms varying from slower drug clearance to drug transport activity alteration. Conclusion: Results from most studies included in this review suggest that SNPs in Plasmodium falciparum genes participate in the resistance against various antimalarial drugs via several mechanisms and may be necessary for parasite survival when stressed.

Malaria and Pregnancy.

Recent identification of local mosquito-borne transmission of malaria in Florida, Texas, and Maryland and increasing travel to malaria-endemic countries raise the likelihood that U.S. obstetricians might encounter a pregnant patient with malaria. Pregnancy increases the risk of becoming infected with malaria and of developing severe disease. Malaria during pregnancy also increases the risk of adverse pregnancy outcomes, including low birth weight, pregnancy loss, and preterm birth; thus, prevention and prompt diagnosis and treatment are essential. Diagnosis can be challenging during pregnancy among persons with partial immunity because placental sequestration of parasite-infected red blood cells can result in lower parasite levels in peripheral blood. Treatment for uncomplicated malaria depends on the expected resistance pattern, which is determined by the specific Plasmodium species identified and where infection was acquired. For severe disease, parenteral artesunate treatment needs to be initiated immediately. Given the dire consequences of malaria in pregnancy, prevention is crucial. For persons born and raised in endemic areas, interventions include use of insecticide-treated bed nets, intermittent preventive treatment, and prompt diagnosis and treatment of illness. U.S. pregnant persons should avoid travel to endemic countries; for unavoidable travel, pregnant travelers should receive chemoprophylaxis and avoid mosquito bites. Although the risk is low to U.S. pregnant persons who are not traveling internationally, avoiding mosquito bites is important, especially for pregnant persons residing in or visiting areas with recent local mosquito-borne transmission.

Supplementation of honey bee production colonies with a native beneficial microbe mixture.

Honey bee colonies form a complex superorganism, with individual and social immune defences that control overall colony health. Sometimes these defences are not enough to overcome infections by parasites and pathogens. For that reason, several studies have been conducted to evaluate different strategies to improve honey bee health. Anovel alternative that is being studied is the use of beneficial microbes. In a previous study, we isolated and characterised bacterial strains from the native gut microbiota of honey bees. Four Apilactobacillus kunkeei strains were mixed and administered in laboratory models to evaluate their potential beneficial effect on larvae and adult bees. This beneficial microbe mixture was safe; it did not affect the expression of immune-related genes, and it was able to decrease the mortality caused by Paenibacillus larvae infection in larvae and reduced the Nosema ceranae spore number in infected adult honey bees. In the present study, we aimed to delve into the impact of the administration of this beneficial microbe mixture on honey bee colonies, under field conditions. The mixture was administered in sugar syrup using lyophilised bacterial cells or fresh cultures, by aspersion or sprayed and feeder, once a week for three consecutive weeks, in autumn or spring 2015, 2017 and 2019. Colony strength parameters were estimated before the administration, and one and three months later. Simultaneously different samples were collected to evaluate the infection levels of parasites and pathogens. The results showed that administering the beneficial microbe mixture decreased or stabilised the infection by N. ceranae or Varroa destructor in some trials but not in others. However, it failed to improve the colony's strength parameters or honey production. Therefore, field studies can be a game-changer when beneficial microbes for honey bees are tested, and meticulous studies should be performed to test their effectiveness.

Diversity and abundance of parasitoid fauna associated with the pests of certain medicinal plants of West Bengal

A preliminary study was conducted from 2021 to 2022 to explore the parasitoid fauna associated with insect pests and their per cent parasitism levels in the field as well as to understand the diversity of parasitoids in the medicinal plants ecosystem under northern tracts of West Bengal. In course of the study, a total of ten parasitoid species belonging to 5 families from 2 orders were observed in this ecosystem. Hymenopteran parasitoids were dominant, i.e., more than 90% and only one fly parasitoid species from Diptera belonging to the family Tachinidae was observed. Amongst the hymenopteran parasitoids, braconids were the prime species, found parasitizing various insect pests. All these parasitoids were observed attacking lepidopteran caterpillars which were predominant defoliators on various medicinal plants. The per cent parasitism by Copidosoma sp. on Helcystogramma hibisci was 38% which was the highest and found effective in the suppression of pest population.

CGAS-STING Pathway Activation during Trypanosoma cruzi Infection Leads to Tissue-Dependent Parasite Control.

Host cell invasion by Trypanosoma cruzi is a markedly silent process, with limited host transcriptional changes indicative of innate immune recognition, except for a modest type I IFN (IFN-I) response. In this study, we show that T. cruzi-induced IFN-β production was nearly abolished in primary murine cGAS-/- or stimulator of IFN genes (STING)-deficient (STINGGt) macrophages and fibroblasts. T. cruzi infection did not impact the ability of IFN-regulatory factor reporter macrophages to respond to classical cGAS-STING agonists, indicating that the limited IFN-β induction is not due to active parasite suppression. cGAS-/-, STINGGt, and IFN-α/β receptor-/- (IFNAR-/-) macrophages infected with T. cruzi yielded significantly higher numbers of amastigotes compared with wild-type macrophages; however, the impact of the STING pathway during infection invivo is more complex. Despite an initial increase in parasite growth, STINGGt and IFNAR-/- mice ultimately had lower parasite burden in footpads as compared with wild-type mice, demonstrating a role for IFN-I expression in potentiating parasite growth at the infection site. STING pathway activation had little impact on parasite levels in the skeletal muscle; however, in the heart, cGAS-/- and STINGGt mice, but not IFNAR-/- mice, accumulated higher acute parasite loads, suggesting a protective role of STING sensing of T. cruzi in this organ that was independent of IFN-I. Together, these results demonstrate that host cGAS-STING senses T. cruzi infection, enhancing parasite growth at the site of entry, and contributes to acute-phase parasite restriction in the heart, a major site of tissue damage in chronic T. cruzi infection.

Exploration of rhizosphere-dwelling nematophagous Trichoderma spp. using novel ‘bait technique’ with root-knot nematode Meloidogyne incognita

Throughout the world Trichoderma spp. are majorly used as biocontrol agents for managing the economically important plant-parasitic nematodes. We employed a novel strategy to investigate the variety of rhizosphere dwelling Trichoderma species using the nematode Meloidogyne incognita as prey bait. Nine nematophagous Trichoderma spp., validated morphologically and molecularly, were discovered during the expedition in several agroclimatic zones of India. Molecular phylogenetic analysis of these species along with the reported Trichoderma spp. from ‘Harzianum clade’ from India indicated the true identity of Indian T. harzianum sensu stricto to be disputed. Nematophagous nature of the isolated species was confirmed through the presence of extracellular lytic enzymes, secondary metabolites, volatile organic compounds, Huperzine A, and tri-gene cluster variability. Besides, the most promising T. yunnanense isolate, shortlisted based on its in vitro potential against M. incognita, showed the highest levels of nematode parasitism, egg hatching inhibition and juvenile mortality compared to all other isolates and species. Expression of green fluorescent protein in T. yunnanense helped tracking its infection in the juveniles and further validated the nematode parasitizing capacity. The chosen isolate decreased the multiplication factor of M. incognita in pot culture assays and in organically produced capsicum in nematode-infected sick soil. It is interesting that the isolate also markedly increased the plant growth and yield, which was a bonus. Therefore, the performance of T. yunnanense demonstrated through various strategies instills high confidence to propose it as a prospective species for developing as commercially potent nematode biocontrol agent.

Community structure, seasonal dynamics, and impact of some biological parameters of the African catfish Clarias gariepinus on the infection level of the helminth parasites.

Fish parasitic diseases impose a major economic concern on aquaculture. Identified parasites of Clarias gariepinus include one monogenean, Macrogyrodactylus clarii (gills), three digeneans Orientocreadium batrachoides, Eumasenia bangweulensis and Sanguinicola sp. (intestine), two cestodes Tetracampose ciliotheca and Monobothrioides chalmersius (intestine) and two nematodes Paracamallanus cyathopharynx and Procamallanus pseudolaeviconchus (intestine and stomach). Most nematodes, digeneans and cestodes occurred in all months of the study period. However, M. clarii and Sanguinicola sp. disappeared for 6 and 8months of the year, respectively. The digenean group was the most dominant followed by the cestode and nematode groups, respectively. The nematodes attained the highest infection rate over the digeneans and cestodes while the monogenean M. clarii recorded the lowest infection rate. The infection level of examined parasites varied seasonally, but no overall significant pattern was detected. E. bangweulensis showed a highly significant difference for all parameters seasonally. A higher prevalence was obvious in males than females for most parasites, and the opposite for the mean intensity except for P. pseudolaeviconchus which was significantly different between females and males in the mean abundance. There were variations in the relationship between the host condition factor and helminth parasite infection levels. O. batrachoides, E. bangweulensis and P. cyathopharynx recorded the highest infection level in class II. The mean prevalence was highly significantly different between host classes for T. ciliotheca, M. chalmersius and P. pseudolaeviconchus.

Parasite effects on receivers in animal communication: Hidden impacts on behavior, ecology, and evolution

Parasites exert a profound effect on biological processes. In animal communication, parasite effects on signalers are well-known drivers of the evolution of communication systems. Receiver behavior is also likely to be altered when they are parasitized or at risk of parasitism, but these effects have received much less attention. Here, we present a broad framework for understanding the consequences of parasitism on receivers for behavioral, ecological, and evolutionary processes. First, we outline the different kinds of effects parasites can have on receivers, including effects on signal processing from the many parasites that inhabit, occlude, or damage the sensory periphery and the central nervous system or that affect physiological processes that support these organs, and effects on receiver response strategies. We then demonstrate how understanding parasite effects on receivers could answer important questions about the mechanistic causes and functional consequences of variation in animal communication systems. Variation in parasitism levels is a likely source of among-individual differences in response to signals, which can affect receiver fitness and, through effects on signaler fitness, impact population levels of signal variability. The prevalence of parasitic effects on specific sensory organs may be an important selective force for the evolution of elaborate and multimodal signals. Finally, host–parasite coevolution across heterogeneous landscapes will generate geographic variation in communication systems, which could ultimately lead to evolutionary divergence. We discuss applications of experimental techniques to manipulate parasitism levels and point the way forward by calling for integrative research collaborations between parasitologists, neurobiologists, and behavioral and evolutionary ecologists.

Biological activities of 4H-thiochromen-4-one 1,1-dioxide derivatives against tropical disease parasites: A target-based drug design approach

A promising strategy for developing novel therapies against tropical diseases, including malaria, leishmaniasis, and trypanosomiasis, is to detect biological targets such as trypanothione reductase, a vital parasite enzyme that regulates oxidative stress. This enzyme is highly selective and conserved in the Trypanosotidae family and has an ortholog in the Plasmodium genus. Previous studies have established that an isosteric replacement of naphthoquinone's carbonyl group with a sulfone group leads to compounds with high bioactivity and selectivity (half-maximal inhibitory concentration = 3 μM against intracellular amastigotes of L. panamensis, selectivity index = 153 over monocytes U-937). In this study, we analyzed the reactive oxygen species (ROS) levels of parasites through indirect measurements of the tryparedoxin system after treatment with these isosteric compounds. This strategy proved that a significant increase in the ROS levels and strong mitochondrial perturbation led to the death of parasites due to cell homeostatic imbalance, confirming the compounds' effectiveness in disrupting this important metabolic pathway. To improve understanding of the parasite-molecule interaction, 27 new compounds were synthesized and assessed against parasites of the three principal tropical diseases (malaria, leishmaniasis, and trypanosomiasis), displaying an EC50 below 10 μM and good correlation with in-silico studies, indicating that the 4H-thiochromen-4-one 1,1-dioxide core is a special allosteric modulator. It can interact in the binding pocket through key amino acids like Ser-14, Leu-17, Trp-21, Ser-109, Tyr-110, and Met-113, leading to interhelical disruption.

Comparison of indoor (refrigerated) versus outdoor winter storage of commercial honey bee, Apis mellifera (Hymenoptera: Apidae), colonies in the Western United States.

Honey bees (Apis mellifera L.) are critical to the pollination of many important crops in the United States, and one crop that demands large numbers of colonies early each year is almonds. To provide adequate numbers of colonies for almond pollination, many beekeepers move colonies of bees to high-density holding yards in California in late fall, where the bees can fly and forage, but little natural pollen and nectar is available. In recent years, high colony losses have occurred in some operations following this management strategy, and alternative approaches, including indoor storage of colonies, have become more commonly used. The current study evaluated colonies kept indoors (refrigerated and/or controlled atmosphere) for the winter compared with those kept outdoors in either Washington or California. Colonies were evaluated for strength (frames of bees), brood area, lipid composition of worker bees, colony weight and survival, parasitic mites (Varroa mites, tracheal mites), and pathogens (Nosema spp.). No differences were found in colony weight, survival, parasitic mite levels, or pathogen prevalence among the treatments. Colonies stored indoors and outdoors in WA had significantly more frames of bees and less brood present after the storage period than colonies stored outdoors in CA. Lipid composition of honey bees stored indoors was significantly higher than colonies stored outdoors in WA or CA. The implications of these findings for overall colony health and improved pollination activity are discussed.

Haematological alterations of mullet Planiliza abu (Heckel, 1843) naturally infected by Ergasilus mosulensis Rahemo, 1982 (Copepoda: Ergaslidae) in a private fish farm from Basrah Province, Iraq

Generally, there is no previous information about haematological parameters of parasitized fish maintained in fish farms in Al- Mashab area, Basrah, Iraq. In this study, the effects of parasitism by the copepod Ergasilus mosulensis. on haemoglobin (Hb), haematocrit (HCT), red blood cells (RBCS), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), and leucocytes were analysed in infected Planiliza abu. The high level of parasitism found in infected fishes was responsible for alterations in blood picture Hb, HCT, RBCS, MCV, MCH, MCHC, and leucocytes (P > 0.05). This is the first report regarding hematology of cultivated freshwater fish which are infected with parasitic copepods in Basrah Province.

Prevalence and Burden of Gastrointestinal Parasites among University Students at Dar es Salaam University College of Education, Tanzania

Gastrointestinal parasites cause major health problems in many tropical and sub-tropical countries including Tanzania. However, information on the status of these infections is often scanty, especially among young adults including students in higher learning institutions. During December 2020 to June 2021, a total of 272 faecal samples from university students at Dar es Salaam University College of Education (DUCE) were examined for parasites using the Kato Katz technique and analysed for infection levels based on standard guidelines. Detected parasites were identified as Schistosoma mansoni (8.1%), hookworms (1.5%), Trichuris trichiura (0.4%) and Hymenolepis diminuta (0.4%), with an overall prevalence of 10.4%. S. mansoni had the highest mean intensity of 792 eggs per gram (epg) of faeces, while H. diminuta was the least intense parasite (120 epg). While infection levels of most parasites were generally low, S. mansoni intensity was categorized as heavy based on standard criteria. The findings indicated the public importance of parasitic infections among young adults who are often excluded from most intervention programmes. Thus, further studies to elucidate the magnitude of the infections among young adults in higher learning institutions in Tanzania is warranted alongside regular prescriptions of anthelminthics and sanitation and hygiene education to reduce parasite transmissions.

Fish length, diet, and depth drive Anisakis levels in a zooplankton-feeding fish

Parasites play a key but overlooked role in the functioning of marine systems. Understanding the drivers of parasite infection in fish is thus crucial. Anisakis levels in the Atlantic horse mackerel Trachurus trachurus resulted from both biotic and environmental drivers. Ontogenic variation of the diet was the first driver of Anisakis level. The nonlinear pattern confirmed that the variation in parasitism was related to ontogenetic dietary shifts. The impact of depth on diet also explained the effect of depth on parasites. In deeper areas, fish only access pelagic prey, where Anisakis presence is high, consistent with the pelagic nature of the parasite. Finally, relative proportions of parasitic burden by tissue appeared to be driven by lipid content. In lipid-rich species like T. trachurus, Anisakis can find favorable conditions in the body cavity and in muscle and avoid the liver. Parasitism levels in fish are thus the result of patterns at play at different levels, and these factors should be better considered before being able to include parasites in an integrated vision of marine ecosystem functioning.

Discovery, SAR and mechanistic studies of quinazolinone-based acetamide derivatives in experimental visceral leishmaniasis

Towards identification of novel therapeutic candidates, a series of quinazolinone-based acetamide derivatives were synthesized and assessed for their anti-leishmanial efficacy. Amongst synthesized derivatives, compounds F12, F27 and F30 demonstrated remarkable activity towards intracellular L. donovani amastigotes in vitro, with IC50 values of 5.76 ± 0.84 μM, 3.39 ± 0.85 μM and 8.26 ± 1.23 μM against promastigotes, and 6.02 μM ± 0.52, 3.55 ± 0.22 μM and 6.23 ± 0.13 μM against amastigotes, respectively. Oral administration of compounds F12 and F27 entailed >85% reduction in organ parasite burden in L. donovani-infected BALB/c mice and hamsters, by promoting host-protective Th1 cytokine response. In host J774 macrophages, mechanistic studies revealed inhibition of PI3K/Akt/CREB axis, resulting in a decrease of IL-10 versus IL-12 release upon F27 treatment. In silico docking studies conducted with lead compound, F27 demonstrated plausible inhibition of Leishmania prolyl-tRNA synthetase, which was validated via detection of decreased proline levels in parasites and induction of amino acid starvation, leading to G1 cell cycle arrest and autophagy-mediated programmed cell death of L. donovani promastigotes. Structure−activity analysis and study of pharmacokinetic and physicochemical parameters suggest oral availability and underscore F27 as a promising lead for anti-leishmanial drug development.

Minimal sharing of nosematid and trypanosomatid parasites between honey bees and other bees, but extensive sharing of Crithidia between bumble and mason bees

We document gut parasites in co-occurring Apis, Bombus, and Osmia spp. in the Northern Virginia region, USA. Trypanosomatidea occurred in sixty percent of specimens and 13% carried Nosematidae. We found strong host partitioning: Lotmaria passim and Vairimorpha (Nosema) ceranae predominated in Apis, and Crithidia bombi and V. bombi in Bombus. We did not detect pathogen spread from Apis to Bombus but did detect sharing of C. bombi between Bombus and Osmia, higher parasite levels in Apis at sites with apiaries, and clustering of Vairimopha infection. Given the presence of C. bombi in Osmia, we suggest disease sharing across taxa be monitored.