Organophosphates, carbamates and synthetic pyrethroids are commonly used in Thailand to control mosquito vectors; however, long-term use of insecticides in vector control has led to the rapid development of insecticide resistance. In this study, we screened Bacillus thuringiensis strains as biological control agents for potential toxins against mosquito larvae as an additional control tool. Preliminary bioassays conducted on 434 strains demonstrated that 41 strains (11.64%) and 14 strains (3.97%) achieved 100% mortality against Ae. aegypti and Cx. quinquefasciatus larvae, respectively. Three strains (JC690, JC691, and JC699) showed toxicity to both mosquito species, compared with the reference Bti strain. Strains JC691 demonstrated the highest efficacy against Ae. aegypti and Cx. quinquefasciatus, with an LC50 value of 6.96 × 104 CFU/ml and 1.16 × 103 CFU/ml, respectively. A comparison of LC50 values revealed that JC691 exhibited higher efficacy against Cx. quinquefasciatus than that by Bti (Bti LC50: 8.89 × 10⁴ CFU/ml) but lower efficacy against Ae. aegypti (Bti LC50: 1.99 × 10³ CFU/ml). Scanning electron microscopy revealed that JC690, JC691, and JC699 are rod-shaped, have oval spores, and produce bi-pyramidal crystal proteins. Protein profile analysis using SDS-PAGE demonstrated distinct differences between these Thailand strains (JC690, JC691, and JC699) and the reference Bti strain. All three Thailand strains contained cry1I and cry2A genes, and only JC691 harbored the cry32 gene. Bayesian inference and maximum likelihood phylogenetic analyses of cry32 indicated that the partial sequences of cry32 in JC691 from Thailand were distinct from those of other B. thuringiensis strains from different countries. This study demonstrates the potential of JC690, JC691, and JC699 as biocontrol agents for Ae. aegypti and Cx. quinquefasciatus.
{"title":"Larvicidal activity of Bacillus thuringiensis strains against Aedes aegypti and Culex quinquefasciatus mosquitoes","authors":"Prakai Rajchanuwong , Sawaporn Peaboon , Ratchadawan Ngoen-Klan , Atsalek Rattanawannee , Atirat Noosidum , Boonhiang Promdonkoy , Jariya Chanpaisaeng , Theeraphap Chareonviriyaphap","doi":"10.1016/j.crpvbd.2025.100245","DOIUrl":"10.1016/j.crpvbd.2025.100245","url":null,"abstract":"<div><div>Organophosphates, carbamates and synthetic pyrethroids are commonly used in Thailand to control mosquito vectors; however, long-term use of insecticides in vector control has led to the rapid development of insecticide resistance. In this study, we screened <em>Bacillus thuringiensis</em> strains as biological control agents for potential toxins against mosquito larvae as an additional control tool. Preliminary bioassays conducted on 434 strains demonstrated that 41 strains (11.64%) and 14 strains (3.97%) achieved 100% mortality against <em>Ae. aegypti</em> and <em>Cx. quinquefasciatus</em> larvae, respectively. Three strains (JC690, JC691, and JC699) showed toxicity to both mosquito species, compared with the reference Bti strain. Strains JC691 demonstrated the highest efficacy against <em>Ae. aegypti</em> and <em>Cx. quinquefasciatus</em>, with an LC<sub>50</sub> value of 6.96 × 10<sup>4</sup> CFU/ml and 1.16 × 10<sup>3</sup> CFU/ml, respectively. A comparison of LC<sub>50</sub> values revealed that JC691 exhibited higher efficacy against <em>Cx. quinquefasciatus</em> than that by Bti (Bti LC<sub>50</sub>: 8.89 × 10⁴ CFU/ml) but lower efficacy against <em>Ae. aegypti</em> (Bti LC<sub>50</sub>: 1.99 × 10³ CFU/ml). Scanning electron microscopy revealed that JC690, JC691, and JC699 are rod-shaped, have oval spores, and produce bi-pyramidal crystal proteins. Protein profile analysis using SDS-PAGE demonstrated distinct differences between these Thailand strains (JC690, JC691, and JC699) and the reference Bti strain. All three Thailand strains contained <em>cry</em>1I and <em>cry</em>2A genes, and only JC691 harbored the <em>cry</em>32 gene. Bayesian inference and maximum likelihood phylogenetic analyses of <em>cry</em>32 indicated that the partial sequences of <em>cry</em>32 in JC691 from Thailand were distinct from those of other <em>B. thuringiensis</em> strains from different countries. This study demonstrates the potential of JC690, JC691, and JC699 as biocontrol agents for <em>Ae. aegypti</em> and <em>Cx. quinquefasciatus</em>.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100245"},"PeriodicalIF":1.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.crpvbd.2025.100244
Yaimie Lopez , Aitor Casas-Sanchez , Byron Arana , Nidia Rizzo , Erick Duran , Norma Padilla , Andrea de la Vega , Esteban Bustamante , Álvaro Acosta-Serrano , Renata Mendizabal-Cabrera
Cutaneous leishmaniasis (CL) is a parasitic vector-borne disease prevalent in 90 countries. Despite its endemicity in Guatemala, key transmission factors are still unknown. To address this, we characterized sand fly populations and Leishmania parasites in a Guatemalan community in 2022. We visited the households of 23 patients with lesions compatible with CL, sampled for sand flies and analysed Leishmania spp. presence in patients’ skin scrapings and in collected sand flies. We collected 93 sand flies, predominantly females including the vector species Nyssomyia ylephiletor, Bichromomyia olmeca and Lutzomyia cruciata. Nyssomyia ylephiletor was the most abundant species indoors. Four Leishmania spp. were identified including L. panamensis, L. guyanensis, L. braziliensis and L. infantum in CL lesions, L. guyanensis complex species (L. guyanensis or L. panamensis) and Leishmania sp. in sand flies. Sand fly species positive for Leishmania spp. were Ny. ylephiletor, Dampfomyia deleoni, Dampfomyia sp. and Brumptomyia sp. Blood-meal analysis revealed human and pig blood in engorged Ny. ylephiletor collected inside and in the proximity of the households. This is the first report of L. guyanensis in Guatemalan patients and provides insights into CL transmission dynamics, suggesting potential indoor transmission, pending more studies.
{"title":"Insights into the transmission cycle of cutaneous leishmaniasis from an endemic community in rural Guatemala","authors":"Yaimie Lopez , Aitor Casas-Sanchez , Byron Arana , Nidia Rizzo , Erick Duran , Norma Padilla , Andrea de la Vega , Esteban Bustamante , Álvaro Acosta-Serrano , Renata Mendizabal-Cabrera","doi":"10.1016/j.crpvbd.2025.100244","DOIUrl":"10.1016/j.crpvbd.2025.100244","url":null,"abstract":"<div><div>Cutaneous leishmaniasis (CL) is a parasitic vector-borne disease prevalent in 90 countries. Despite its endemicity in Guatemala, key transmission factors are still unknown. To address this, we characterized sand fly populations and <em>Leishmania</em> parasites in a Guatemalan community in 2022. We visited the households of 23 patients with lesions compatible with CL, sampled for sand flies and analysed <em>Leishmania</em> spp. presence in patients’ skin scrapings and in collected sand flies. We collected 93 sand flies, predominantly females including the vector species <em>Nyssomyia ylephiletor</em>, <em>Bichromomyia olmeca</em> and <em>Lutzomyia cruciata</em>. <em>Nyssomyia ylephiletor</em> was the most abundant species indoors. Four <em>Leishmania</em> spp. were identified including <em>L. panamensis</em>, <em>L. guyanensis</em>, <em>L. braziliensis</em> and <em>L. infantum</em> in CL lesions, <em>L. guyanensis</em> complex species (<em>L. guyanensis</em> or <em>L. panamensis</em>) and <em>Leishmania</em> sp. in sand flies. Sand fly species positive for <em>Leishmania</em> spp. were <em>Ny. ylephiletor</em>, <em>Dampfomyia deleoni</em>, <em>Dampfomyia</em> sp<em>.</em> and <em>Brumptomyia</em> sp. Blood-meal analysis revealed human and pig blood in engorged <em>Ny. ylephiletor</em> collected inside and in the proximity of the households. This is the first report of <em>L. guyanensis</em> in Guatemalan patients and provides insights into CL transmission dynamics, suggesting potential indoor transmission, pending more studies.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100244"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143360315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.crpvbd.2025.100269
Mathilde S. Varegg, Ian D. Woolsey, Lucy J. Robertson, Alejandro Jiménez-Meléndez
Cryptosporidium research has been hampered by the lack of in vitro models that can recapitulate the life cycle of the parasite, thus relying on repeated animal infections. Traditional in vitro systems, employing cancerous cell lines, have been unable to support sexual reproduction, but have been widely employed for drug screening assays and allowed transcriptome mapping of the parasite, but extrapolation of those results to in vivo infections is limited. In recent years, intestinal organoids (enteroids), grown as 3D structures, have come to be recognized as more physiologically relevant, complex systems, since they more accurately reproduce the cell populations present in the small intestine. A key advantage of these systems is their ability to fulfil the life cycle of the parasite. However, studies employing bovine organoids, the target species of the major zoonotic species Cryptosporidium parvum, are lacking. Future research should emphasize bioengineered systems, with heterogeneous populations of intestinal epithelial and mesenchymal cells, to advance the in vitro field closer to in vivo infection models. The present review summarizes the history of cell line use in Cryptosporidium research and the most recent advances in organoids, bio-engineered and organ-on-a-chip platforms, including methodological approaches used to facilitate exposure of the apical side of the target cells to the parasite, and the influence of mechanical forces and microenvironment.
{"title":"Rapid review: Recent advances in in vitro models for the study of Cryptosporidium parvum","authors":"Mathilde S. Varegg, Ian D. Woolsey, Lucy J. Robertson, Alejandro Jiménez-Meléndez","doi":"10.1016/j.crpvbd.2025.100269","DOIUrl":"10.1016/j.crpvbd.2025.100269","url":null,"abstract":"<div><div><em>Cryptosporidium</em> research has been hampered by the lack of <em>in vitro</em> models that can recapitulate the life cycle of the parasite, thus relying on repeated animal infections. Traditional <em>in vitro</em> systems, employing cancerous cell lines, have been unable to support sexual reproduction, but have been widely employed for drug screening assays and allowed transcriptome mapping of the parasite, but extrapolation of those results to <em>in vivo</em> infections is limited. In recent years, intestinal organoids (enteroids), grown as 3D structures, have come to be recognized as more physiologically relevant, complex systems, since they more accurately reproduce the cell populations present in the small intestine. A key advantage of these systems is their ability to fulfil the life cycle of the parasite. However, studies employing bovine organoids, the target species of the major zoonotic species <em>Cryptosporidium parvum</em>, are lacking. Future research should emphasize bioengineered systems, with heterogeneous populations of intestinal epithelial and mesenchymal cells, to advance the <em>in vitro</em> field closer to <em>in vivo</em> infection models. The present review summarizes the history of cell line use in <em>Cryptosporidium</em> research and the most recent advances in organoids, bio-engineered and organ-on-a-chip platforms, including methodological approaches used to facilitate exposure of the apical side of the target cells to the parasite, and the influence of mechanical forces and microenvironment.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100269"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144116551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.crpvbd.2025.100317
Daisy Shaw , William J.S. Edwards , Gary S. Thompson , Martin Kolisko , Eleni Gentekaki , Anastasios D. Tsaousis
Blastocystis is the most prevalent intestinal protist in humans, yet its role in gut health remains poorly understood. Increasing evidence suggests subtype-specific interactions with the gut microbiome and metabolome may underlie its variable associations with health and disease. In this pilot study, we performed an integrated analysis of the microbiota and metabolite profiles of nine Blastocystis subtypes (ST1-ST9) grown in vitro using xenic cultures. Using 16S rRNA amplicon sequencing and proton nuclear magnetic resonance (1H-NMR) metabolomics, we characterised the microbial communities and extracellular metabolites across subtypes. ST3 exhibited the most distinct microbiome and metabolomic profile, characterised by a significant enrichment of short-chain fatty acids (SCFAs) and amino-acid derivatives. Benzoate, a known antimicrobial, was uniquely downregulated in ST3. Linear discriminant analysis identified several bacterial genera, such as Methanobrevibacter and Enterobacter, as biomarkers for ST3. Correlations between key metabolites and microbial taxa suggest potential syntrophic interactions. These findings suggest that individual Blastocystis subtypes establish distinct microenvironments in vitro, with implications for their ecological roles in vivo. Our study provides a foundational framework for understanding subtype-specific biology and offers a platform for improving culture conditions and investigating host-microbe interactions.
{"title":"Microbial and metabolic signatures among Blastocystis subtypes ST1-ST9 in xenic cultures","authors":"Daisy Shaw , William J.S. Edwards , Gary S. Thompson , Martin Kolisko , Eleni Gentekaki , Anastasios D. Tsaousis","doi":"10.1016/j.crpvbd.2025.100317","DOIUrl":"10.1016/j.crpvbd.2025.100317","url":null,"abstract":"<div><div><em>Blastocystis</em> is the most prevalent intestinal protist in humans, yet its role in gut health remains poorly understood. Increasing evidence suggests subtype-specific interactions with the gut microbiome and metabolome may underlie its variable associations with health and disease. In this pilot study, we performed an integrated analysis of the microbiota and metabolite profiles of nine <em>Blastocystis</em> subtypes (ST1-ST9) grown <em>in vitro</em> using xenic cultures. Using 16S rRNA amplicon sequencing and proton nuclear magnetic resonance (<sup>1</sup>H-NMR) metabolomics, we characterised the microbial communities and extracellular metabolites across subtypes. ST3 exhibited the most distinct microbiome and metabolomic profile, characterised by a significant enrichment of short-chain fatty acids (SCFAs) and amino-acid derivatives. Benzoate, a known antimicrobial, was uniquely downregulated in ST3. Linear discriminant analysis identified several bacterial genera, such as <em>Methanobrevibacter</em> and <em>Enterobacter</em>, as biomarkers for ST3. Correlations between key metabolites and microbial taxa suggest potential syntrophic interactions. These findings suggest that individual <em>Blastocystis</em> subtypes establish distinct microenvironments <em>in vitro</em>, with implications for their ecological roles <em>in vivo</em>. Our study provides a foundational framework for understanding subtype-specific biology and offers a platform for improving culture conditions and investigating host-microbe interactions.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"8 ","pages":"Article 100317"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.crpvbd.2025.100322
Taylor G. Donaldson , Brian T. Rich , Miranda R. Peterson , Hsiao-Hsuan Wang , William E. Grant , Donald B. Thomas , Kimberly H. Lohmeyer , Adalberto Á. Pérez de León , Pete D. Teel
Knowledge gaps on the dynamics of cattle fever tick-cattle-habitat-climate interactions in South Texas and their influence on the efficacy of treatments to eliminate infestations with the Rhipicephalus (Boophilus) microplus prevent optimal interventions by the Cattle Fever Tick Eradication Program (CFTEP). The CFTEP has been operating in the USA since 1907. This study applied the concept of location intelligence to examine movement, habitat use and selection by cattle in a highly heterogeneous coastal landscape infested with R. microplus. Cattle interface with white-tailed deer and nilgai, which are alternate wildlife hosts of R. microplus, in this unique South Texas landscape. Location intelligence data obtained from GPS collars placed on steers between August and December 2019 that were treated as part of the protocol to eradicate R. microplus were used to track their movement in the tick-infested rangeland of the Laguna Atascosa National Wildlife Refuge. GIS spatial analyses were conducted to determine time-of-day (morning, midday, evening, midnight), and seasonal differences in: (i) distance of cattle movements; (ii) cattle habitat use and selection; (iii) spatial spread of cattle; and (iv) distance to closest watering site. Cattle movement patterns, habitat use and selection, spatial spread, and distance to closest watering sites were significantly different between the summer and autumn periods. These variables were also significantly different by time-of-day periods within and between seasonal periods. Habitat use and selection by steers are discussed in the context of range sites and vegetation types. Nine ixodid tick species were documented through the inspection of hosts (cattle, nilgai, and white-tailed deer). Rhipicephalus microplus was collected from white-tailed deer and nilgai during cull hunts, as well as from project cattle that missed one anti-tick treatment due to adverse weather conditions. Tick-host-habitat-climate interactions involving cattle and wildlife, future grazing strategies for anti-tick treated cattle, and potential impacts of tick-refugia are discussed in the context of location intelligence. Spatiotemporal patterns of cattle habitat use and selection across an infested coastal landscape in South Texas revealed by location intelligence could inform adaptive operations of the CFTEP to keep the USA free of R. microplus.
{"title":"Location intelligence unveils seasonal spatiotemporal pattern shifts of habitat use and selection by cattle across a South Texas coastal landscape infested with Rhipicephalus microplus","authors":"Taylor G. Donaldson , Brian T. Rich , Miranda R. Peterson , Hsiao-Hsuan Wang , William E. Grant , Donald B. Thomas , Kimberly H. Lohmeyer , Adalberto Á. Pérez de León , Pete D. Teel","doi":"10.1016/j.crpvbd.2025.100322","DOIUrl":"10.1016/j.crpvbd.2025.100322","url":null,"abstract":"<div><div>Knowledge gaps on the dynamics of cattle fever tick-cattle-habitat-climate interactions in South Texas and their influence on the efficacy of treatments to eliminate infestations with the <em>Rhipicephalus</em> (<em>Boophilus</em>) <em>microplus</em> prevent optimal interventions by the Cattle Fever Tick Eradication Program (CFTEP). The CFTEP has been operating in the USA since 1907. This study applied the concept of location intelligence to examine movement, habitat use and selection by cattle in a highly heterogeneous coastal landscape infested with <em>R. microplus</em>. Cattle interface with white-tailed deer and nilgai, which are alternate wildlife hosts of <em>R</em>. <em>microplus</em>, in this unique South Texas landscape. Location intelligence data obtained from GPS collars placed on steers between August and December 2019 that were treated as part of the protocol to eradicate <em>R. microplus</em> were used to track their movement in the tick-infested rangeland of the Laguna Atascosa National Wildlife Refuge. GIS spatial analyses were conducted to determine time-of-day (morning, midday, evening, midnight), and seasonal differences in: (i) distance of cattle movements; (ii) cattle habitat use and selection; (iii) spatial spread of cattle; and (iv) distance to closest watering site. Cattle movement patterns, habitat use and selection, spatial spread, and distance to closest watering sites were significantly different between the summer and autumn periods. These variables were also significantly different by time-of-day periods within and between seasonal periods. Habitat use and selection by steers are discussed in the context of range sites and vegetation types. Nine ixodid tick species were documented through the inspection of hosts (cattle, nilgai, and white-tailed deer). <em>Rhipicephalus microplus</em> was collected from white-tailed deer and nilgai during cull hunts, as well as from project cattle that missed one anti-tick treatment due to adverse weather conditions. Tick-host-habitat-climate interactions involving cattle and wildlife, future grazing strategies for anti-tick treated cattle, and potential impacts of tick-refugia are discussed in the context of location intelligence. Spatiotemporal patterns of cattle habitat use and selection across an infested coastal landscape in South Texas revealed by location intelligence could inform adaptive operations of the CFTEP to keep the USA free of <em>R</em>. <em>microplus</em>.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"8 ","pages":"Article 100322"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bats represent over 1400 species globally, accounting for approximately one-fifth of all mammalian diversity, yet their gastrointestinal parasite communities remain understudied. Among these parasites, the genus Eimeria is one of the most commonly documented coccidian groups infecting bats. To date, more than 40 Eimeria spp. have been described from bats worldwide; however, molecular data are limited, and their evolutionary relationships with congeners infecting other vertebrate hosts remain largely unresolved. This study aims to elucidate the evolutionary connections between Eimeria parasites infecting bats and rodents, addressing a key question about shared ancestry and host-switching events across deeply divergent hosts. We investigated the genetic diversity and phylogenetic relationships of Eimeria spp. infecting Thai bats. Ninety-six genomic DNA samples extracted from bat guano, collected across six geographically distinct sites in prior research, were screened using SSU rRNA-PCR and nanopore amplicon sequencing. Host identification based on vertebrate cox1 gene sequencing revealed seven bat species (Pteropus lylei, Taphozous melanopogon, Cynopterus brachyotis, Eonycteris spelaea, Mops plicatus, Hipposideros armiger, and Pteropus vampyrus) along with the Hipposideros larvatus species complex. Haplotype network construction and phylogenetic analyses using Bayesian inference and maximum likelihood identified five putative genetic clusters of Eimeria sequences, including novel Haplogroups 1 and 2 that formed clearly distinct groups. The remaining three clusters showed close genetic affinities to known Eimeria species from bats (Eimeria sp. Bat10 and Eimeria sp. Bat31) and rodents (E. ferrisi). Notably, despite the deep evolutionary divergence between bats and rodents, Eimeria parasites infecting these hosts did not form entirely separate clades. Both phylogenies consistently revealed the polyphyletic nature of bat-derived Eimeria species, with multiple independent lineages interspersed among rodent taxa. This pattern supports hypotheses of shared ancestry or host-switching events, highlighting the complex evolutionary dynamics shaping Eimeria diversity across vertebrate hosts. The widespread distribution and genetic patterns observed in Haplogroup 1 suggest a recent population expansion potentially driven by ecological adaptability and host range dynamics. By focusing on the evolutionary relationships between bat and rodent Eimeria, this study advances our understanding of Eimeria diversity and host-parasite coevolution, emphasizing the importance of integrative molecular approaches in unravelling parasite evolutionary history across vertebrate taxa.
{"title":"New insights into molecular characterization and genetic diversity of Eimeria coccidian parasites in bats from diverse geographical regions of Thailand using nanopore-based DNA metabarcoding","authors":"Chatchapon Sricharoensuk , Pathamet Khositharattanakool , Puckavadee Somwang , Supaporn Wacharapluesadee , Padet Siriyasatien , Kanok Preativatanyou","doi":"10.1016/j.crpvbd.2025.100327","DOIUrl":"10.1016/j.crpvbd.2025.100327","url":null,"abstract":"<div><div>Bats represent over 1400 species globally, accounting for approximately one-fifth of all mammalian diversity, yet their gastrointestinal parasite communities remain understudied. Among these parasites, the genus <em>Eimeria</em> is one of the most commonly documented coccidian groups infecting bats. To date, more than 40 <em>Eimeria</em> spp. have been described from bats worldwide; however, molecular data are limited, and their evolutionary relationships with congeners infecting other vertebrate hosts remain largely unresolved. This study aims to elucidate the evolutionary connections between <em>Eimeria</em> parasites infecting bats and rodents, addressing a key question about shared ancestry and host-switching events across deeply divergent hosts. We investigated the genetic diversity and phylogenetic relationships of <em>Eimeria</em> spp. infecting Thai bats. Ninety-six genomic DNA samples extracted from bat guano, collected across six geographically distinct sites in prior research, were screened using SSU rRNA-PCR and nanopore amplicon sequencing. Host identification based on vertebrate <em>cox</em>1 gene sequencing revealed seven bat species (<em>Pteropus lylei</em>, <em>Taphozous melanopogon</em>, <em>Cynopterus brachyotis</em>, <em>Eonycteris spelaea</em>, <em>Mops plicatus</em>, <em>Hipposideros armiger</em>, and <em>Pteropus vampyrus</em>) along with the <em>Hipposideros larvatus</em> species complex. Haplotype network construction and phylogenetic analyses using Bayesian inference and maximum likelihood identified five putative genetic clusters of <em>Eimeria</em> sequences, including novel Haplogroups 1 and 2 that formed clearly distinct groups. The remaining three clusters showed close genetic affinities to known <em>Eimeria</em> species from bats (<em>Eimeria</em> sp. Bat10 and <em>Eimeria</em> sp. Bat31) and rodents (<em>E. ferrisi</em>). Notably, despite the deep evolutionary divergence between bats and rodents, <em>Eimeria</em> parasites infecting these hosts did not form entirely separate clades. Both phylogenies consistently revealed the polyphyletic nature of bat-derived <em>Eimeria</em> species, with multiple independent lineages interspersed among rodent taxa. This pattern supports hypotheses of shared ancestry or host-switching events, highlighting the complex evolutionary dynamics shaping <em>Eimeria</em> diversity across vertebrate hosts. The widespread distribution and genetic patterns observed in Haplogroup 1 suggest a recent population expansion potentially driven by ecological adaptability and host range dynamics. By focusing on the evolutionary relationships between bat and rodent <em>Eimeria</em>, this study advances our understanding of <em>Eimeria</em> diversity and host-parasite coevolution, emphasizing the importance of integrative molecular approaches in unravelling parasite evolutionary history across vertebrate taxa.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"8 ","pages":"Article 100327"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145320145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.crpvbd.2025.100332
Ross Bacchetti , Paula McCormack , Lisa Connelly, Derek J. Brown, Dominique L. Chaput, Claire L. Alexander
Cryptosporidium parvum is a zoonotic protozoan parasite of human and veterinary public health concern that causes gastrointestinal disease. Animal contact is a major risk factor for C. parvum outbreaks which require thorough investigation through the use of molecular subtyping. Recently, a multi-locus variable-number tandem repeat analysis (MLVA) scheme was established for C. parvum, offering improved subtyping resolution compared to the commonly used single-locus 60 kDa glycoprotein gene (gp60) subtyping approach. Using the C. parvum MLVA scheme, the genetic diversity of known gp60 subtyped faecal DNA extracts collected between April 1st 2023 and March 31st 2024 was explored. A representative group of a common Scottish gp60 subtype (IIaA15G2R1, n = 28) was analysed by MLVA and found to consist of 8 distinct complete MLVA profiles, with 4-12-5-7-27-36-16 (n = 12) being the most common. Genetic diversity within samples involved in three historic animal contact outbreaks (Outbreaks A, B and C) was investigated. Outbreak A, involving a single gp60 subtype (IIaA19G1R1), consisted of only one MLVA profile (4-12-5-8-27-15-17). Outbreak B was caused by two gp60 subtypes (IIaA17G1R1 and IIaA15G2R1), which were further subdivided into four MLVA profiles, two per gp60 subtype (4-14-4-7-27-37-15 and 4-14-5-7-27-27-15, and 4-13-4-8-27-31-17 and 4-12-5-7-27-42-16, respectively). Lastly, Outbreak C, thought to have two-point sources of infection, involved one gp60 subtype (IIaA15G2R1), which was subdivided into four distinct MLVA profiles (4-12-5-7-27-36-16, 4-12-5-7-27-32-15, 4-12-5-7-27-30-15, and 4-14-5-7-36-33-15). Improved MLVA resolution allowed outbreak specimens with insufficient epidemiological data to be linked to a source through sharing a common MLVA profile.
小隐孢子虫是一种人畜共患的原生动物寄生虫，引起人类和兽医的公共卫生关注，引起胃肠道疾病。动物接触是小弧菌暴发的主要危险因素，需要通过分子分型进行彻底调查。最近，建立了一种多位点可变数串联重复分析（MLVA）方案，与常用的单位点60 kDa糖蛋白基因（gp60）亚型分型方法相比，该方案提供了更高的亚型分型分辨率。利用小孢子虫MLVA方案，对2023年4月1日至2024年3月31日收集的已知gp60亚型粪便DNA提取物的遗传多样性进行了研究。通过MLVA分析了一个常见苏格兰gp60亚型（IIaA15G2R1, n = 28）的代表性群体，发现由8个不同的完整MLVA谱组成，其中4-12-5-7-27-36-16 （n = 12）是最常见的。调查了三次历史性动物接触性暴发（暴发A、B和C）所涉及样本的遗传多样性。爆发A涉及单一gp60亚型（IIaA19G1R1），仅包括一个MLVA谱（4-12-5-8-27-15-17）。爆发B由2个gp60亚型（IIaA17G1R1和IIaA15G2R1）引起，进一步细分为4个MLVA亚型，每个gp60亚型各2个（分别为4-14-4-7-27-37-15和4-14-5-7-27-27-15，以及4-13-4-8-27-31-17和4-12-5-7-27-42-16）。最后，爆发C被认为具有两点传染源，涉及一种gp60亚型（IIaA15G2R1），该亚型被细分为四种不同的MLVA亚型（4-12-5-7-27-36-16、4-12-5-7-27-32-15、4-12-5-7-27-30-15和4-14-5-7-36-33-15）。改进的MLVA分辨率允许通过共享共同的MLVA概况将流行病学数据不足的暴发标本与一个来源联系起来。
{"title":"Investigating genetic diversity within Cryptosporidium parvum outbreaks using multi-locus variable number tandem repeat analysis","authors":"Ross Bacchetti , Paula McCormack , Lisa Connelly, Derek J. Brown, Dominique L. Chaput, Claire L. Alexander","doi":"10.1016/j.crpvbd.2025.100332","DOIUrl":"10.1016/j.crpvbd.2025.100332","url":null,"abstract":"<div><div><em>Cryptosporidium parvum</em> is a zoonotic protozoan parasite of human and veterinary public health concern that causes gastrointestinal disease. Animal contact is a major risk factor for <em>C. parvum</em> outbreaks which require thorough investigation through the use of molecular subtyping. Recently, a multi-locus variable-number tandem repeat analysis (MLVA) scheme was established for <em>C. parvum</em>, offering improved subtyping resolution compared to the commonly used single-locus 60 kDa glycoprotein gene (<em>gp60</em>) subtyping approach. Using the <em>C. parvum</em> MLVA scheme, the genetic diversity of known <em>gp60</em> subtyped faecal DNA extracts collected between April 1st 2023 and March 31st 2024 was explored. A representative group of a common Scottish <em>gp60</em> subtype (IIaA15G2R1, <em>n</em> = 28) was analysed by MLVA and found to consist of 8 distinct complete MLVA profiles, with 4-12-5-7-27-36-16 (<em>n</em> = 12) being the most common. Genetic diversity within samples involved in three historic animal contact outbreaks (Outbreaks A, B and C) was investigated. Outbreak A, involving a single <em>gp60</em> subtype (IIaA19G1R1), consisted of only one MLVA profile (4-12-5-8-27-15-17). Outbreak B was caused by two <em>gp60</em> subtypes (IIaA17G1R1 and IIaA15G2R1), which were further subdivided into four MLVA profiles, two per <em>gp60</em> subtype (4-14-4-7-27-37-15 and 4-14-5-7-27-27-15, and 4-13-4-8-27-31-17 and 4-12-5-7-27-42-16, respectively). Lastly, Outbreak C, thought to have two-point sources of infection, involved one <em>gp60</em> subtype (IIaA15G2R1), which was subdivided into four distinct MLVA profiles (4-12-5-7-27-36-16, 4-12-5-7-27-32-15, 4-12-5-7-27-30-15, and 4-14-5-7-36-33-15). Improved MLVA resolution allowed outbreak specimens with insufficient epidemiological data to be linked to a source through sharing a common MLVA profile.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"8 ","pages":"Article 100332"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145465154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Malaria is a global infectious disease, causing hundreds of thousands of deaths annually. This study presents an age-structured mathematical model for malaria vaccination that captures human and mosquito host interactions. Fundamental mathematical properties were established, and the stability of equilibria was analyzed in relation to the effective reproduction number . The system admits two equilibrium points: a malaria-free equilibrium and a malaria-endemic equilibrium. Analytical results showed that the malaria-free equilibrium is locally and globally asymptotically stable when . Conversely, the malaria-endemic equilibrium is globally asymptotically stable when . A sensitivity analysis of was performed to identify parameters influencing malaria transmission dynamics for prioritization in control strategies. The numerical results corroborate theoretical findings, illustrating that the model solutions converge to equilibrium states over time. This implies that with effective vaccinations, treatments, and insecticide vector control, malaria transmission could be reduced to nearly zero, potentially leading to complete eradication of the disease. This study offers key insights on the integration of vaccination with complementary malaria control strategies, informing public health planning for sustainable malaria control in endemic regions.
{"title":"Age-structured vaccination strategies in mathematical modeling of malaria transmission","authors":"Andualem Tekle Haringo, Legesse Lemecha Obsu, Feyissa Kebede Bushu","doi":"10.1016/j.crpvbd.2025.100328","DOIUrl":"10.1016/j.crpvbd.2025.100328","url":null,"abstract":"<div><div>Malaria is a global infectious disease, causing hundreds of thousands of deaths annually. This study presents an age-structured mathematical model for malaria vaccination that captures human and mosquito host interactions. Fundamental mathematical properties were established, and the stability of equilibria was analyzed in relation to the effective reproduction number <span><math><mrow><mo>(</mo><msub><mi>R</mi><mi>e</mi></msub><mo>)</mo></mrow></math></span>. The system admits two equilibrium points: a malaria-free equilibrium and a malaria-endemic equilibrium. Analytical results showed that the malaria-free equilibrium is locally and globally asymptotically stable when <span><math><mrow><msub><mi>R</mi><mi>e</mi></msub><mo><</mo><mspace></mspace><mn>1</mn></mrow></math></span>. Conversely, the malaria-endemic equilibrium is globally asymptotically stable when <span><math><mrow><msub><mi>R</mi><mi>e</mi></msub><mo>></mo><mspace></mspace><mn>1</mn></mrow></math></span>. A sensitivity analysis of <span><math><mrow><msub><mi>R</mi><mi>e</mi></msub></mrow></math></span> was performed to identify parameters influencing malaria transmission dynamics for prioritization in control strategies. The numerical results corroborate theoretical findings, illustrating that the model solutions converge to equilibrium states over time. This implies that with effective vaccinations, treatments, and insecticide vector control, malaria transmission could be reduced to nearly zero, potentially leading to complete eradication of the disease. This study offers key insights on the integration of vaccination with complementary malaria control strategies, informing public health planning for sustainable malaria control in endemic regions.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"8 ","pages":"Article 100328"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sand flies are principal vectors of Leishmania spp. and Trypanosoma spp. Identifying precise vector species is crucial for effective control. We conducted a study on the species distribution of phlebotomine sand flies in cave-dwelling and non-cave-dwelling in four southern provinces of Thailand. In this study, we collected 621 sand flies (346 females and 275 males) and identified all specimens based on morphology and DNA barcoding, employing cytochrome c oxidase subunit 1 (cox1) and cytochrome b (cytb) genes. In female specimens, we also screened the small subunit 18S ribosomal RNA (18S rRNA) gene for Leishmania spp. and Trypanosoma spp. Morphologically, 467 (75.2%) sand flies were identified to species level, 47 (7.57%) to subgenus level, and 107 (17.23%) to genus level. These included Idiophlebotomus asperulus (43.48%), Sergentomyia khawi (26.73%), S. anodontis (2.25%), S. brevicaulis (2.25%), Grassomyia indica (0.48%), Phlebotomus (Euphlebotomus) spp. (4.83%), Phlebotomus (Lewisius) spp. (2.74%), Sergentomyia spp. (9.18%), and Phlebotomus spp. (8.05%). Among the 107 specimens identified to genus level, DNA barcoding further identified 49 (45.79%) as Sergentomyia barraudi (1.61%), S. bailyi (0.16%), Phlebotomus kiangsuensis (2.9%), and Ph. stantoni (1.61%). No Leishmania DNA was detected, but Trypanosoma DNA was found in females of S. khawi from Narathiwat Province. Expanding genetic reference databases of sand flies located in four provinces of southern Thailand will improve barcoding accuracy. Understanding sand fly species composition and distribution is imperative for vector control and disease prevention in Thailand.
{"title":"Species distribution and screening of Trypanosoma DNA in phlebotomine sand flies from four southern provinces of Thailand","authors":"Nantatchaporn Klaiklueng , Rawadee Kumlert , Sopavadee Moonmake , Toon Ruang-areerate , Padet Siriyasatien , Sakone Sunantaraporn , Darawan Wanachiwanawin , Pichet Ruenchit , Sirichit Wongkamchai","doi":"10.1016/j.crpvbd.2025.100263","DOIUrl":"10.1016/j.crpvbd.2025.100263","url":null,"abstract":"<div><div>Sand flies are principal vectors of <em>Leishmania</em> spp. and <em>Trypanosoma</em> spp. Identifying precise vector species is crucial for effective control. We conducted a study on the species distribution of phlebotomine sand flies in cave-dwelling and non-cave-dwelling in four southern provinces of Thailand. In this study, we collected 621 sand flies (346 females and 275 males) and identified all specimens based on morphology and DNA barcoding, employing cytochrome <em>c</em> oxidase subunit 1 (<em>cox</em>1) and cytochrome <em>b</em> (<em>cytb</em>) genes. In female specimens, we also screened the small subunit 18S ribosomal RNA (18S rRNA) gene for <em>Leishmania</em> spp. and <em>Trypanosoma</em> spp. Morphologically, 467 (75.2%) sand flies were identified to species level, 47 (7.57%) to subgenus level, and 107 (17.23%) to genus level. These included <em>Idiophlebotomus asperulus</em> (43.48%), <em>Sergentomyia khawi</em> (26.73%), <em>S. anodontis</em> (2.25%), <em>S. brevicaulis</em> (2.25%), <em>Grassomyia indica</em> (0.48%), <em>Phlebotomus</em> (<em>Euphlebotomus</em>) spp. (4.83%), <em>Phlebotomus</em> (<em>Lewisius</em>) spp. (2.74%), <em>Sergentomyia</em> spp. (9.18%), and <em>Phlebotomus</em> spp. (8.05%). Among the 107 specimens identified to genus level, DNA barcoding further identified 49 (45.79%) as <em>Sergentomyia barraudi</em> (1.61%), <em>S. bailyi</em> (0.16%), <em>Phlebotomus kiangsuensis</em> (2.9%), and <em>Ph. stantoni</em> (1.61%). No <em>Leishmania</em> DNA was detected, but <em>Trypanosoma</em> DNA was found in females of <em>S. khawi</em> from Narathiwat Province. Expanding genetic reference databases of sand flies located in four provinces of southern Thailand will improve barcoding accuracy. Understanding sand fly species composition and distribution is imperative for vector control and disease prevention in Thailand.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100263"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.crpvbd.2025.100246
Maria V. Murgia , Laurie Widder , Catherine A. Hill
Tick-borne diseases (TBDs) impact human and animal health on a global scale. Prevention of TBDs relies primarily on prevention of tick bites. New bite-prevention technologies are needed as an alternative to current approaches such as topical repellents and treated clothing which suffer low user compliance. To date, no passive spatial devices have been commercialized for area protection against ticks. The BiteBarrier (formerly the Personal Insect Repellent Kit, PIRK), a passive, lightweight device that emits transfluthrin, offers to fill this gap. In a previous study, we demonstrated contact toxicity of the BiteBarrier substrate to three tick species, Ixodes scapularis, Dermacentor variabilis and Amblyomma americanum, and reported differences in efficacy depending on species and short-range spatial efficacy against I. scapularis adult females. Here, we extended analyses and demonstrated modest spatial activity of the BiteBarrier substrate against A. americanum and D. variabilis adult females. Using a dual-choice behavioral assay, we showed that the three tick species preferred an area of untreated substrate. Lastly, we present a novel perimeter assay, developed to assess the efficacy of the BiteBarrier ground-based prototype against ticks. At short-range in a Peet Grady-style chamber, the BiteBarrier perimeter induced greater than 90% knockdown of I. scapularis adult females at 1 and 2 h post-exposure and 90% mortality at 48 h post-exposure. Taken together, study findings indicate the potential of the BiteBarrier perimeter to control ticks at near range and potentially, to protect against tick bites.
{"title":"The BiteBarrier perimeter: A passive spatial device for tick control and bite prevention","authors":"Maria V. Murgia , Laurie Widder , Catherine A. Hill","doi":"10.1016/j.crpvbd.2025.100246","DOIUrl":"10.1016/j.crpvbd.2025.100246","url":null,"abstract":"<div><div>Tick-borne diseases (TBDs) impact human and animal health on a global scale. Prevention of TBDs relies primarily on prevention of tick bites. New bite-prevention technologies are needed as an alternative to current approaches such as topical repellents and treated clothing which suffer low user compliance. To date, no passive spatial devices have been commercialized for area protection against ticks. The BiteBarrier (formerly the Personal Insect Repellent Kit, PIRK), a passive, lightweight device that emits transfluthrin, offers to fill this gap. In a previous study, we demonstrated contact toxicity of the BiteBarrier substrate to three tick species, <em>Ixodes scapularis</em>, <em>Dermacentor variabilis</em> and <em>Amblyomma americanum</em>, and reported differences in efficacy depending on species and short-range spatial efficacy against <em>I. scapularis</em> adult females. Here, we extended analyses and demonstrated modest spatial activity of the BiteBarrier substrate against <em>A. americanum</em> and <em>D. variabilis</em> adult females. Using a dual-choice behavioral assay, we showed that the three tick species preferred an area of untreated substrate. Lastly, we present a novel perimeter assay, developed to assess the efficacy of the BiteBarrier ground-based prototype against ticks. At short-range in a Peet Grady-style chamber, the BiteBarrier perimeter induced greater than 90% knockdown of <em>I. scapularis</em> adult females at 1 and 2 h post-exposure and 90% mortality at 48 h post-exposure. Taken together, study findings indicate the potential of the BiteBarrier perimeter to control ticks at near range and potentially, to protect against tick bites.</div></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"7 ","pages":"Article 100246"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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