Specific Parasite Research Articles

Helminth Fauna of bats (Chiroptera) of the National Park «Smolny» (European Russia)

The purpose of the research is to study the fauna of parasitic worms of bats (Chiroptera) in the National Park «Smolny» (Republic of Mordovia).Materials and methods. In 2018–2021, the helminth fauna of 445 ind. of 8 bat species at 10 locations in the National Park «Smolny» was studied using the method of complete helminthological necropsy. Parasitic worms were collected, fixed and processed using standard methods.Results and discussion. A total of 31 helminth species were recorded in bats of the National Park "Smolny": 3 – cestodes, 20 – trematodes and 8 – nematodes. The trematode Prosthodendrium cryptholecithum and the larva of the nematode Physaloptera clausa were found for the first time in Russian bats. The trematodes Gyrabascus amphoraeformis and G. oppositus were found for the first time in bats of the Middle Volga Region. The determining factors of helminth infection of bats are feeding predominantly on aquatic insects and poor contact of animals with the terrestrial environment. Of the 31 species of parasites found in bats, 28 species are specific parasites of bats, which is explained by the ecological isolation of this group of flying mammals and the antiquity of the co-evolution of bats and their parasites. An annotated list of helminths of bats is given, including their systematic position, host range, localization, infection rates, sites of detection and distribution. Among bats, the helminth fauna of the common noctule (15 species), Daubenton's bat (13) and Nathusius' pipistrelle (12) is the richest. The helminth fauna of the pond bat (6 species), lesser noctule (5) and Natterer's bat (4) is less represented. The greatest distribution in bats of the National Park "Smolny" has the trematode Plagiorchis koreanus and the nematode Pterothominx neopulchra noted each in 6 species of hosts. Only one helminth species (nematode Physocephalus sexalatus), which is of medical and veterinary importance as the causative agent of a dangerous helminthosis, has been recorded in bats.

Research Note: Reduction of Salmonella load in Brazilian commercial chicken farms using INSPEKTOR®: a bacteriophage-based product

Salmonella is a zoonotic pathogen transmitted through food and one of the four leading global causes of diarrheal disease in humans. Brazil is the world's largest exporter of poultry meat, and as such, Brazilian farms routinely detect and prevent Salmonella. The last official monitoring and control in poultry slaughter establishments in Brazil in 2023 detected Salmonella spp. in 14.80 % of samples from chickens, and those Salmonella-positive samples were classified as serovar Minnesota in 65.76 % of samples, serovar Heidelberg in 16.10 % of samples and another 26 or more serovars non-typeable represented a total of 18.13 % of the samples. However, despite these measures, several poultry diseases and outbreaks have been reported in recent decades, requiring permanent disease control. Bacteriophages, which act as specific parasites of bacterial cells, can contribute to food safety. This study evaluated the effectiveness of the INSPEKTOR® phage cocktail for controlling Salmonella on 17 commercial broiler farms on a total of 4 experimental groups (1 control cycle and 3 consecutive treatment cycles) using 3 doses of the cocktail for each cycle. Salmonella load was quantified (DNA copies/mL) by real-time PCR using the invA marker for Salmonella spp., together with serovars Minnesota and Heidelberg, which are relevant to the industry in Brazil. Our results showed that INSPEKTOR® reduced Salmonella load from 0.5 up to 6 logs in the treatment cycles 3 and 4 compared to the control cycle, and reduced the load of Minnesota and Heidelberg in all 3 treatment cycles. This study is relevant as it involves applying a phage cocktail capable of reducing Salmonella load in real poultry production systems with over 3 million broiler chickens.

Spatial clustering of hosts can favor specialist parasites.

Generalist parasites seem to enjoy the clear ecological advantage of a greater chance to find a host, and genetic trade-offs are therefore often invoked to explain why specialists can coexist with or outcompete generalists. Here we develop an alternative perspective based on optimal foraging theory to explain why spatial clustering can favor specialists even without genetic trade-offs. Using analytical and simulation models inspired by bacteriophage, we examine the optimal use of two hosts, one yielding greater reproductive success for the parasite than the other. We find that a phage may optimally ignore the worse host when the two hosts are clustered together in dense, ephemeral patches. We model conditions that enhance or reduce this selective benefit to a specialist parasite and show that it is eliminated entirely when the hosts occur only in separate patches. These results show that specialists can be favored even when trade-offs are weak or absent and emphasize the importance of spatiotemporal heterogeneity in models of optimal niche breadth.

Effects of environmental factors on host-parasite interaction patterns in backyard-tethered goats of Kerala, India

The environment is the most important stratum in the epidemiological triad of a parasitic disease and any variations in the environmental factors may decide the dynamic occurrence and existence of different lifecycle stages of these parasites. The present study investigated the correlations between key biometeorological and demographical parameters with the incidence of different gastrointestinal parasites and hemoparasites among goats. Four hundred and thirty-two goats were screened for parasitic infection in a yearlong survey conducted from July 2022 to June 2023 in the Teaching Veterinary Clinical Complex, Mannuthy, Kerala, India. The weather parameters (Tmax, Tmin, RH, THI, and bright sunshine hours), air quality parameters [AQI, PM2.5, and PM10], and demographic parameters (gender and age) were recorded along with the test positivity of different categories of gastrointestinal parasites and hemoparasites in goats by routine fecal sample examination and blood smear examination, respectively. The infection level was ranked based on the severity of the infection. The mean and daily variations in biometeorological parameters were calculated and the data were statistically analyzed to figure out the pertinent correlations in host-parasite-environment interaction patterns. High levels of parasitic infections with significant month-wise variations and climate-correlated peak infection patterns were noticed. The incidence of parasites was negatively correlated to all parameters except humidity, indicating more severe parasitism during monsoon months. The significant variations in the host-parasite interaction dynamics point towards the need for detailed explorations concerning the lifecycle of each specific parasite with a focus on the possible environment-favourable and resistant lifecycle stages. Future studies may be designed from a biometeorological perspective to develop a crucial understanding of host-parasite-environment interactions in goats ensuring sustainable goat farming.

Serological profile of voluntary blood donors in a blood bank of tertiary health care centre- An institution-based study

Background: The safe transfusion of blood facilities is an essential component of an efficient, excellent healthcare sector. Unsafe blood transfusions can be a cause of transfusion-transmitted infections and can be lethal. The present study was conducted to find out the seroprevalence of HBsAg, HCV, HIV, malarial parasites, and syphilis in voluntary blood donors in a tertiary care center. Materials and methods: This prospective study was conducted at the blood bank of the Shri Mahant Indiresh Hospital, Dehradun. 16413 samples from all blood donations were screened for HBsAg, HCV, HIV 1 and 2, malaria, and syphilis. Samples were collected in vacutainers at the time of blood donation and screened for HIV 1and2, HBsAg, and HCV using the fourth-generation enzyme-linked immunosorbent assay technique. Syphilis was tested by Treponema antibodies using the VITROS Syphilis TPA Reagent Pack. Malaria was tested by pan malaria card, monoclonal anti-pan specific parasite lactate dehydrogenase antibody conjugated to colloidal gold, and another monoclonal anti-pan specific parasite lactate dehydrogenase antibody immobilized on a nitrocellulose strip in a thin line. Results: Out of 16413 blood donors 342(2.1%) were found to be seropositive and 16071 (97.9%) were found to be seronegative. The total number of donors, who were found positive for HBsAg/Anti HCV was 1 (0.3%). Out of the seropositive cases, HBsAg, HCV, HIV, and Syphilis infections constituted 28.9%, 27.5, 14.6, and 28.7% cases respectively. Conclusions: There is a need for the development and implementation of stringent donor selection and sensitive screening tests to reduce the risk of acquiring transfusion-transmitted illnesses.

Assessment of the Genetic Diversity of the Monogenean Gill Parasite Lamellodiscus echeneis (Monogenea) Infecting Wild and Cage-Reared Populations of Sparus aurata (Teleostei) from the Mediterranean Sea.

The diplectanid monogenean Lamellodiscus echeneis (Wagener, 1857) is a specific and common gill parasite of the gilthead seabream Sparus aurata Linnaeus, 1758, in the Mediterranean Sea. Few isolated molecular studies of this monogenean have been conducted, and its population structure and genetic diversity are poorly understood. This study represents the first analysis of the population genetics of L. echeneis, isolated from wild and cage-reared gilthead seabream from fifteen localities in both the Southern (Tunisia) and Northern (Italy and Spain) regions of the Mediterranean Sea, using nuclear ITS rDNA markers and a partial fragment of the mitochondrial gene cytochrome oxidase subunit I (COI). The phylogenetic trees based on the newly obtained dataset and the previously published sequences of L. echeneis corroborated the spread of only a single species throughout the Mediterranean Sea. The star-like haplotypes network, inferred by COI sequences, suggested a recent population expansion of L. echeneis. This is supported by the observed high haplotype diversity (Hd = 0.918) and low nucleotide diversity (Pi = 0.01595). Population structure-based AMOVA for two groups (the Adriatic Sea and the rest of the Mediterranean Sea) attributed 35.39% of the total variation to differences within populations, 16.63% to differences among populations within groups, and 47.99% to differences among groups. Fixation indices were significant, with a high FST value (0.64612), likely related to the divergence of the parasite populations from the Adriatic Sea and other Mediterranean regions. Phylogenetic analyses grouped all samples into the main clade corresponding to L. echeneis from several localities. This study provides insight into the genetic variation between L. echeneis populations, and did not show a clear genetic structure between populations of L. echeneis throughout Tunisian, Italian, and Spanish localities, which can be attributed to the considerable gene flow between the populations favoured by the potential for host dispersion within the Mediterranean Sea. Finally, haplotypes shared between wild and cage-reared hosts provided evidence for the potential for cross-infection between wild and farmed hosts in the Mediterranean Sea.

Multispecies interactions and the community context of the evolution of virulence.

Pairwise host-parasite relationships are typically embedded in broader networks of ecological interactions, which have the potential to shape parasite evolutionary trajectories. Understanding this 'community context' of pathogen evolution is vital for wildlife, agricultural and human systems alike, as pathogens typically infect more than one host-and these hosts may have independent ecological relationships. Here, we introduce an eco-evolutionary model examining ecological feedback across a range of host-host interactions. Specifically, we analyse a model of the evolution of virulence of a parasite infecting two hosts exhibiting competitive, mutualistic or exploitative relationships. We first find that parasite specialism is necessary for inter-host interactions to impact parasite evolution. Furthermore, we find generally that increasing competition between hosts leads to higher shared parasite virulence while increasing mutualism leads to lower virulence. In exploitative host-host interactions, the particular form of parasite specialization is critical-for instance, specialization in terms of onward transmission, host tolerance or intra-host pathogen growth rate lead to distinct evolutionary outcomes under the same host-host interactions. Our work provides testable hypotheses for multi-host disease systems, predicts how changing interaction networks may impact virulence evolution and broadly demonstrates the importance of looking beyond pairwise relationships to understand evolution in realistic community contexts.

Recent update on cerebral sparganosis: A bibliometric analysis and scientific mapping.

Human sparganosis, a parasitic infection prevalent in Asia, can progress to cerebral sparganosis, a severe condition with significant neurological symptoms. Diagnosis and treatment are challenging due to its clinical similarity to other infections, highlighting the need for improved detection and management strategies. The aim of this study was to observe research trends, key contributors, gaps in the existing knowledge, diagnosis challenges, effective treatment options, and prevention strategies, providing recommendations for future research directions and clinical practice improvements on cerebral sparganosis. A bibliometric analysis was conducted by extracting 139 documents from the Scopus database in June 2024. The retrieved data were analyzed using the R package's Bibliometrix (Biblioshiny) and VOSviewer. Spanning 97 different sources, the research exhibited an annual growth rate of 2.5%. Annual scientific production revealed fluctuating research activity with peaks in 2010 and 2011 and notable citation peaks in 1996 and 2005, indicating pivotal studies that significantly influenced subsequent research. Early studies focused on diagnosis and specific parasites, while recent studies (2010-2024) have increasingly addressed clinical outcomes, treatment strategies, and advanced diagnostic techniques. Trends revealed a shift towards clinical and diagnostic advancements, with recent emphasis on diagnostic imaging, immunoassays, and the relationship between cerebral sparganosis and brain tumors. In conclusion, the studies on cerebral sparganosis underscore the potential for enhancing clinical practice by improving diagnostic accuracy, informing treatment decisions, and implementing targeted screening efforts based on epidemiology and risk factors. Recommendation to further study needs to notify the cerebral sparganosis in high-risk countries with similar socioeconomic and cultural characteristics to endemic regions, including Indonesia.

Research Progress on Detection of Pathogens in Medical Wastewater by Electrochemical Biosensors.

The detection of pathogens in medical wastewater is crucial due to the high content of pathogenic microorganisms that pose significant risks to public health and the environment. Medical wastewater, which includes waste from infectious disease and tuberculosis facilities, as well as comprehensive medical institutions, contains a variety of pathogens such as bacteria, viruses, fungi, and parasites. Traditional detection methods like nucleic acid detection and immunological assays, while effective, are often time-consuming, expensive, and not suitable for rapid detection in underdeveloped areas. Electrochemical biosensors offer a promising alternative with advantages including simplicity, rapid response, portability, and low cost. This paper reviews the sources of pathogens in medical wastewater, highlighting specific bacteria (e.g., E. coli, Salmonella, Staphylococcus aureus), viruses (e.g., enterovirus, respiratory viruses, hepatitis virus), parasites, and fungi. It also discusses various electrochemical biosensing techniques such as voltammetry, conductometry, impedance, photoelectrochemical, and electrochemiluminescent biosensors. These technologies facilitate the rapid, sensitive, and specific detection of pathogens, thereby supporting public health and environmental safety. Future research may should pay more attention on enhancing sensor sensitivity and specificity, developing portable and cost-effective devices, and innovating detection methods for diverse pathogens to improve public health protection and environmental monitoring.

Long-term balancing selection for pathogen resistance maintains trans-species polymorphisms in a planktonic crustacean

Balancing selection is an evolutionary process that maintains genetic polymorphisms at selected loci and strongly reduces the likelihood of allele fixation. When allelic polymorphisms that predate speciation events are maintained independently in the resulting lineages, a pattern of trans-species polymorphisms may occur. Trans-species polymorphisms have been identified for loci related to mating systems and the MHC, but they are generally rare. Trans-species polymorphisms in disease loci are believed to be a consequence of long-term host-parasite coevolution by balancing selection, the so-called Red Queen dynamics. Here we scan the genomes of three crustaceans with a divergence of over 15 million years and identify 11 genes containing identical-by-descent trans-species polymorphisms with the same polymorphisms in all three species. Four of these genes display molecular footprints of balancing selection and have a function related to immunity. Three of them are located in or close to loci involved in resistance to a virulent bacterial pathogen, Pasteuria, with which the Daphnia host is known to coevolve. This provides rare evidence of trans-species polymorphisms for loci known to be functionally relevant in interactions with a widespread and highly specific parasite. These findings support the theory that specific antagonistic coevolution is able to maintain genetic diversity over millions of years.

Biocontrol agent amendments shape the soybean rhizosphere in a cyst nematode (Heterodera glycines) conducive soil over a two-year field trial

Plant-associated beneficial microorganisms play a vital role in promoting plant health, fitness, and disease suppression, leading to improved plant growth and protection against specific plant parasites. Microbial amendments may reduce nematode parasite populations and ensure plant yield, yet their long-term impact on the native plant microbiome under field conditions is not well understood. In this study, we evaluated the effectiveness of biocontrol products against soybean cyst nematode (SCN) using two application methods over a two-year period under field conditions. Pochonia chlamydosporia PC10 (Rizotec), Bacillus methylotrophicus UFPEDA 20 (Onix), and Trichoderma koningiopsis GF 362 were applied either through seed inoculation or in-furrow treatment at planting. The treatments effectively reduced the nematode population, with T. koningiopsis showing significant deviations from the control and leading to a notable increase in yield. No difference in the Shannon diversity index was detected for the alpha-diversity of root-associated 16S, ITS2, and 18S communities. The dominant phyla were Proteobacteria, Acidobacteria, Actinobacteria for 16S; Ascomycota, Basidiomycota, Mortierellomycota for ITS2; and Ascomycota, and Cercozoa for 18S. In the 16S community, T. koningiopsis and B. methylotrophicus caused a 25 % increase in the relative abundance of Sphingomonas spp. compared to the control. Additionally, the relative abundance of Mortierella spp. significantly increased by 50 % in both the T. koningiopsis and B. methylotrophicus treatments compared to the control. Both treatments also led to a significant reduction in Fusarium spp. by 37.5 % and 31.5 %, respectively. Co-occurrence network analysis revealed that communities were disrupted after the first application, but grew more intricate and cohesive after the second year of biocontrol product amendment. T. koningiopsis and B. methylotrophicus demonstrated potential in reducing nematode and Fusarium populations, leading to increased yield production. However, under high nematode pressure, relying solely on biocontrol measures does not guarantee a reduction in SCN population or yield improvement. Manipulating the microbial community to reduce harmful organisms and promote biocontrol-related species may offer long-term benefits.

Parasitological examination results of zoo animals in Germany between 2012 and 2022

Parasitic infections in zoo animals are a critical concern for both animal health and management. The aim of this study was to assess the occurrence of endo- and ectoparasites among zoo animals in Germany. A retrospective analysis of the submitted samples of a diverse range of zoo animals (5768) from a ten-year period (2012–2022) was conducted. Overall, 31.1% of those samples tested positive for at least one parasite. In the examined samples, helminths (28.4%) were found more often than protozoans (10.3%) or ectoparasites (0.8%). Among the various animal groups the following parasites were found most commonly: Artiodactyla: Coccidia (34.6%), Strongylida (23.4%); Perissodactyla: Strongylida (19.3%), Ascaridida (12.0%); Carnivora: Ascaridida (16.6%), Coccidia (8.1%); Rodentia: Oxyurida (18.2%), Coccidia (10.5%); Marsupialia: Coccidia (9.4%), Oxyurida (5.9%); Primates: Trichuris spp. (9.7%), Oxyurida (2.2%); Aves: Capillaria (7.8%), Ascaridida (7.6%); Reptilia, Amphibia, Insecta: Oxyurida (18.7%); Pisces: Ciliates (6.2%). Furthermore, potentially zoonotic parasites were identified, including Toxoplasma gondii (0.1%), Cryptosporidium sp. (0.1%). By examining the occurrence of specific parasites, these findings demonstrate the importance of parasites in the context of zoo animal health. They also highlight the need for effective strategies to control parasite burden to improve the overall welfare of zoo animals.

Winter mortality syndrome in Hong Kong oyster (Crassostrea hongkongensis): Causes and impacts

Cultivation of Hong Kong oyster species (Crassostrea hongkongensis, also known as Magallana hongkongensis) in estuarine areas of South China including Hong Kong contributes to almost a quarter of global edible oyster production. Recently, many growers and scientists observed that mass mortality of this species in winter months, i.e., at the time of their harvest. However, the characteristics and patterns of aforementioned winter mortality syndrome (WMS), as well as the potential underlying causes and impacts are yet to be evaluated. In this study, WMS was first described and examined within Hong Kong's cultural areas by employing a combination of interviews, field observations, histological examinations, and molecular analyses to identify the potential pathogen responsible for WMS in this region. Significant mortality in field experiment confirmed the presence of WMS and matched with results from interviews with oyster growers. Eugymnanthea japonica is identified as one of the contributing factors to winter mortality in Hong Kong. Nevertheless, it cannot be definitively established as the primary and sole cause of WMS. Our results and observations suggest that multiple environmental stressors driven primarily by high salinity stress combined with infection by specific parasite, serves as the main cause of this WMS. This study highlighted the knowledge gaps warranting future investigation and proposed potential short-term mitigation strategies to tackle WMS in the region.

Multi-Class Microscopic Image Analysis of Protozoan Parasites Using Convolutional Neural Network

Protozoan parasites cause a wide range of devastating diseases in various kinds of organisms, including humans. It may be lethal if untreated promptly. To detect specific disease-causingorganisms parasites, a wide range of immunological and molecular technologies are now widely available. However, all of this depends on the worker's expertise and are time-consuming, error-prone, and expensive. With the development of technology, compared to traditional biological techniques, convolutional neural networks have reached excellent achievements in image classification, cutting costs while attaining an overall higher accuracy and eliminating human error. Many models include numerous convolutional layers and offer an accuracy between 90 and 95 percent. In this study, 4740 microscopic images of protozoan parasites from six classes with a balanced dataset and an 80–20% split were classified using three convolutional layers with stochastic gradient descent as an optimizer. A 5-fold cross-validation approach is used to evaluate the proposed method. We also examine and evaluate with deep learning models namely VGG16, ResNet50, and InceptionV3. The performance evaluation of the proposed model shows an accuracy of 94% with a precision range (of 0.83-0.99) and a recall range (of 0.76-1.00), respectively. The retrained model was able to recognize and classify all 6 different parasites. Except for class Leishmania, where 24% of images are incorrectly classified as Plasmodium and Trichomonas, the model demonstrates that most cases are correctly identified.

Трематоды рода Apophallus (Trematoda: Heterophyidae) в фауне многоклеточных паразитов Perca fluviatilis (Perciformes, Actinopterygii) в дельте Волги

The living conditions of aquatic organisms in the Volga-Caspian Sea Shipping Canal are determined by a high level of complex multifactor anthropogenic load. As a link in a unified international transport system, the canal serves as an invasive corridor for the settlement of alien organisms, including parasites. The fauna of multicellular parasites Perca fluviatilis (Perciformes) in the canal area was studied. 6 taxa of parasitic organisms have been registered. The nematode Eustrongylides excisus occupies a dominant position in the fauna of macroparasites P. fluviatilis. An alien trematode, Apophallus muehlingi, was discovered associated with the invasive mollusk Lithoglyphus naticoides; the parasite has the status of a codominant species. A specific parasite widely distributed in perch fish populations in the Volga delta, Apophallus donicus, has not been registered. The high degree of invasion of perch by A. muehlingi during the three-year study period indicates the stability of the parasitic subsystem “A. muehlingi – P. fluviatilis”, previously uncharacteristic for this host species in the lower reaches of the Volga. Currently, more favorable conditions have developed for the invasion of perch A. muehlingi than A. donicus in certain areas of the Volga delta. Thus, structural changes were found in the host-parasite relationships systems of the trematodes of the genus Apophallus, which appear in the form of a partial restructuring of the species and host structure of the fauna of macroparasites P. fluviatils in the investigated area of the river. This situation is determined by factors that are largely anthropogenic in nature – changes in the living conditions of hosts and parasites, caused by a combination of fluctuations in the level of the Caspian Sea and the discharge of the Volgograd hydroelectric station, intensive shipping (large volume of cargo transportation) and high fishing pressure. The most likely significant additional factor of changes in the nature of infection of P. fluviatils by trematodes of the genus Apophallus is currently a decrease in the stocks of populations of some massive species of cyprinid fish – the second intermediate hosts of A. muehlingi, for which the parasite is defined as specific.

Gill parasites of Schizocypris altidorsalis (Pisces: Cyprinidae), a threatened freshwater fish in Iran

Context Schizocypris altidorsalis is a fish of very restricted distribution, with its populations being known only from few water reservoirs on the border of Iran and Afghanistan. Aims The aim was to investigate the occurrence and diversity of host-specific Monogenea on this fish. Methods In total, 400 fish were purchased from the market and examined for the presence of Monogenea. Specimens were characterised morphologically and genetically. Key results In total, 26.5% of fish were found to be infected with Monogenea. Further morphological and molecular studies based on the sequences of the 18S, 28S and ITS2 regions suggested that they all belong to a new species, herein named as Paradiplozoon jalalii. Our results suggest that this monogenean is a highly specific parasite of Schizocypris altidorsalis. Conclusions Monogeneans are highly specialised host-specific parasites infecting fish gill. They can adversely affect respiration and excretory functions in fish, making them more vulnerable to illness, leading to population declines. Implications Determining effective strategies for safeguarding endangered fish can be challenging in conflict zones, such as the area studied here. Additionally, the parasite identified in our study, with its blood-feeding habits, could contribute to the extinction of its fish host, subsequently leading to its own extinction. An unanswered question lingers regarding the potential extinction of other symbionts of Schizocypris altidorsalis if the fish faces extinction.

Unmasking the Mechanism behind Miltefosine: Revealing the Disruption of Intracellular Ca2+ Homeostasis as a Rational Therapeutic Target in Leishmaniasis and Chagas Disease.

Originally developed as a chemotherapeutic agent, miltefosine (hexadecylphosphocholine) is an inhibitor of phosphatidylcholine synthesis with proven antiparasitic effects. It is the only oral drug approved for the treatment of Leishmaniasis and American Trypanosomiasis (Chagas disease). Although its precise mechanisms are not yet fully understood, miltefosine exhibits broad-spectrum anti-parasitic effects primarily by disrupting the intracellular Ca2+ homeostasis of the parasites while sparing the human hosts. In addition to its inhibitory effects on phosphatidylcholine synthesis and cytochrome c oxidase, miltefosine has been found to affect the unique giant mitochondria and the acidocalcisomes of parasites. Both of these crucial organelles are involved in Ca2+ regulation. Furthermore, miltefosine has the ability to activate a specific parasite Ca2+ channel that responds to sphingosine, which is different to its L-type VGCC human ortholog. Here, we aimed to provide an overview of recent advancements of the anti-parasitic mechanisms of miltefosine. We also explored its multiple molecular targets and investigated how its pleiotropic effects translate into a rational therapeutic approach for patients afflicted by Leishmaniasis and American Trypanosomiasis. Notably, miltefosine's therapeutic effect extends beyond its impact on the parasite to also positively affect the host's immune system. These findings enhance our understanding on its multi-targeted mechanism of action. Overall, this review sheds light on the intricate molecular actions of miltefosine, highlighting its potential as a promising therapeutic option against these debilitating parasitic diseases.

Abstract 756: Differences in composition, diversity, and function of the fecal microbiota of post-menopausal breast cancer patients compared to healthy, age-matched controls

Abstract Gut microbiota are a community of organisms that colonize the intestinal tract with essential roles in immune function, gut epithelial integrity, and metabolite production. Dysbiosis occurs when the gut microbiota environment is negatively altered causing detrimental changes to these functions, which may predispose an individual to breast cancer development. To understand the relationship between dysbiosis and breast cancer development, fecal microbiota samples were collected from 27 post-menopausal breast cancer patients of varying hormone receptor statuses (ER+HER2-, ER+Her2+, ER-HER2+, or ER-Her2-) prior to starting chemotherapeutic treatment. Samples were compared to 25 healthy controls, and all samples underwent 16srRNA sequencing. Samples from breast cancer patients and control groups were compared for significant differences (P<.05) in alpha (within sample) and beta (between sample) diversity. Using the Shannon Index and Generalized Least Squares Model, significant differences in alpha diversity were identified between all breast cancer types vs. controls (P=.0104), and between ER+HER2- breast cancer vs. controls (P=.00153). Healthy controls exhibited a higher mean Shannon Index than breast cancer patients, thus higher within sample diversity. Using principal coordinate analyses, significant differences in beta diversity were identified between all breast cancer types vs. controls (P = .01199), and ER+HER2- breast cancer vs. control (P = .008991). Further analyses identified significant taxa of microbiota with functions related to breast cancer development and progression. Of note, Lachnoclostridium, a genus of bacteria that can produce β-glucuronidase, which can deconjugate estrogen, was increased in all breast cancer types and ER+HER2- breast cancer when compared to controls. Deconjugation of estrogen can cause elevated blood estrogen levels, potentially increasing Estrogen Receptor binding in hormone-receptor-positive breast cancer. Additionally, Akkermansia, a genus implicated in gut barrier dysfunction, was decreased in ER+HER2- patients, while Parvimonas, a tumorigenic cell-cycle regulator, was increased. Elucidating if these effects are causative or reactionary may have important implications for understanding breast cancer etiology. Samples are currently undergoing additional metagenomic analyses using long-read sequencing to identify specific bacteria, viruses, fungi, parasites, and phages that may be contributing to dysbiosis. Overall, this study is the first, to our knowledge, to employ short and long-read sequencing to the fecal samples of untreated postmenopausal breast cancer patients. We provide mechanistic insight into the relationship between microbiota and breast cancer development, with the intent of informing future patient screening and prevention. Citation Format: Nadia Kabbej, Frederick Ashby, Erika Atencio, Erinn Rosenkrantz, Dominique Day, Khloe Dang, Josee Gauthier, Rachel Newsome, John Sommerville, Taqwa Naas, Raad Gharaibeh, Christian Jobin, Amira Quevedo, Coy D. Heldermon. Differences in composition, diversity, and function of the fecal microbiota of post-menopausal breast cancer patients compared to healthy, age-matched controls [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 756.

Epidemiology and Molecular Characterization of Zoonotic Gastrointestinal Protozoal Infection in Zoo Animals in China.

Zoo animals, harboring zoonotic gastrointestinal protozoal diseases, pose potential hazards to the safety of visitors and animal keepers. This study involved the collection and examination of 400 fresh fecal samples from 68 animal species, obtained from five zoos. The aim of this study was to determine the occurrence, genetic characteristics, and zoonotic potential of common gastrointestinal protists. PCR or nested PCR analysis was conducted on these samples to detect four specific parasites: Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi, and Blastocystis spp. The overall prevalence of Cryptosporidium spp was 0.5% (2/400), G. duodenalis was 6.0% (24/400), Blastocystis spp. was 24.5% (98/400), and E. bieneusi was 13.5% (54/400). G. duodenalis, Blastocystis spp., and E. bieneusi were detected in all of the zoos, exhibiting various zoonotic genotypes or subtypes. G. duodenalis-positive samples exhibited three assemblages (D, E, and B). Blastocystis spp. subtypes (ST1, ST2, ST3, ST4, ST5, ST8, ST10, ST13, and ST14) and one unknown subtype (ST) were identified. A total of 12 genotypes of E. bieneusi were identified, including SC02, BEB6, Type IV, pigEBITS 7, Peru8, PtEb IX, D, CD9, EbpC, SCBB1, CM4, and CM7. Moreover, significant differences in the positive rates among different zoos were observed (p < 0.01). The findings indicate that zoo animals in China are affected by a range of intestinal protozoa infections. Emphasizing molecular identification for specific parasite species or genotypes is crucial for a better understanding of the zoonotic risk. Preventing and controlling parasitic diseases in zoos is not only vital for zoo protection and management but also holds significant public health implications.

Clinical, Pathological and Epidemiological Aspects of Cephalopina titillator Larval, Exciter in Camelus dromedaris from the Rafsanjan Region, Iran

The camel nasal bot fly is an obligate parasite which its larvae causes nasopharyngeal myiasis and the 3rd generation of larvae may cause serious nasal mucosal damage. The present study was conducted on Camelus dromedaris to determine the clinical assessment, seasonal prevalence and also pathological adverse effect of Cephalopina titillator in Rafsanjan region (South east of Iran). Due to history and dental formula, camels were divided into four age groups: less than two years (62 cases), two to five years (86 cases), five to nine (42 cases) and more than nine years (10 cases), which positive cases confirmed in 12 (19.4%%), 31 (36%), 40 (95.2%) and 10 (100%) cases, respectively. The major clinical signs of naturally infected camel was categorized in three main parts; Respiratory signs, nervous behavior and general symptoms which the main ones were related to stridor and nasal discharge. Suspected larvae with average 14.83±4.35 was recovered from 93 infested camels and evaluated microscopically for determining the larval stage. Furthermore, the gross and histopathological findings were recorded by using tissue samples. These non sex related findings showed that with increasing the age, susceptibility to this specific parasite infestation increased as well (p&lt;0.001). No significant seasonal changes were recorded, but the incidence rate was higher in March, April and September. Different larval stage were mostly found in nasal cavity, nasopharyngeal and laryngeal areas which was accompanied by local inflammation, regional edema and serosanguinous exudate. Microscopical findings were showed the epithelial damage along with lymphoid hyperplasia, accumulation of inflammatory cells and remnants of necrotic tissue. However, fibroblasts proliferation, connective tissue formation along with some degrees of atrophy and focal calcification were the significant findings of chronic infestation. These findings indicate the presence of heavy larval infestation in camel of Rafsanjan region which imposes severe economic losses and affect their health, growth and related productions. Therefore, it is recommended to carry out the necessary measures for the biological control of the camel nasal bot fly.